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United States Patent5307173
Yuen , ; et al.April 26, 1994
Title
Apparatus and method using compressed codes for television program record scheduling
Abstract
Encoded video recorder/player timer preprogramming information listed in a television calendar allows a timer preprogramming feature on a video cassette recorder VCR to be programmed using a compressed code of as few as 1 to 8 digits, which are decoded by a decoder built into a television to convert the compressed code into channel, date, time and length information. The compressed code indications associated with each television program can be printed in a television program calendar in advance. The user would use the television remote or controls on the television to enter the code that signifies the program to be recorded. When the codes are entered they are transmitted to the television and the decoded in the television and then the codes themselves and the CDTL information, which is the result of decoding the codes, could be displayed "on screen" so that the user can verify that the proper codes have been entered. Then at the appropriate time the television would transmit the proper commands to a VCR and a cable box, if present, to command the recording of the selected program. This control function can be carried out by using an infrared link by placing infrared transmitters on the television cabinet, preferably at the corners. The television circuitry would include the capability of storing or learning the infrared code protocols for the VCR and the cable box. The decoder can be embedded into various other equipments associated with television, such as a video cassette recorder, cable box or satellite receiver. In any system the decoder would only have to be present in one of the equipments, such as the cable box, which would then at the appropriate time distribute the proper commands to the other equipments such as a VCR and a satellite receiver to record the desired program. The infrared transmitter can be placed in a infrared dome on the equipment, mounted behind the front panel, or attached to a mouse coupled via a cable to the equipment.
Inventors:Yuen; Henry C. (Redondo Beach, CA), Kwoh; Daniel S.  (Rolling Hills Estates, CA)
Assignee:Gemstar Development Corporation (Pasadena, CA)
Appl. No.:829412
Filed:February 3, 1992
Current U.S. Class:386/83 455/151.2 455/181.1 455/186.1 348/731 348/734 386/109 
Field of Search:358/335,191.1,192.1,193.1,194.1 360/33.1 455/170.1,171.1,181.1,185.1,186.1,151.2,151.4,154.1 359/146
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Primary Examiner: McElheny, Jr.; Donald E.
Attorney, Agent or Firm:Christie, Parker & Hale
Parent Case Text


BACKGROUND OF THE INVENTION

This is a continuation in part of pending patent application Ser. No. 07/767,323 filed Sep. 30, 1991 which is continuation in part of Ser. No. 07/676,934 filed Mar. 27, 1991, which is a continuation in part of Ser. No. 07/371,054 filed Jun. 26, 1989 now abandoned, which itself is a continuation in part of Ser. No. 07/289,369, filed Dec. 23, 1988 now abandoned.
Claims

We claim:
1. An apparatus for using compressed codes for recorder preprogramming that comprises:
a television receiver;
means for entering into said television receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a programs;
said television receiver comprising:
means for decoding each compressed code into the combination of channel, date, time-of-day and length commands,
means for storing said combination of channel, date, time-of-day and length commands,
a clock with an output as a function of time,
means for reordering said combinations of channel, time-of-day, date and length commands in said means for storing into temporal order, and
means for comparing the date and time-of-day commands of the temporally earliest in time combination in said means for storing to the output of the clock for a predetermined relation;
means for recording;
means for transmitting record on commands to said means for recording after the predetermined relation is found to exist according to the date and time-of-day commands of said temporally earliest in time combination, wherein said means for transmitting is compounded to said television receiver;
means for channel selection;
wherein said means for transmitting transmit channel select commands to said means for channel selection after the predetermined relation is found to exist according to the channel command of said temporally earliest in time combination wherein said means for transmitting is coupled to said television receiver; and
wherein said means for transmitting transmit record off commands to said means for recording following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.

2. The apparatus of claim 1 wherein said means for entering comprises a television remote controller.

3. The apparatus of claim 1 wherein said means for entering comprises controls coupled to said television receiver.

4. The apparatus of claim 1 wherein said means for channel selection comprises a cable box.

5. The apparatus of claim 1 wherein said means for channel selection comprises a satellite receiver.

6. The apparatus of claim 1 wherein said means for recording comprises a video cassette recorder.

7. The apparatus for using compressed codes for recorder preprogramming of claim 1 which further comprises means for substituting a local channel number for a channel number in at least one said channel command.

8. The apparatus of claim 1 further comprising means for selecting a periodicity for repeating the operation of said means for.

9. The apparatus of claim 1 further comprising a means for warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in times combination.

10. The apparatus of claim 1 wherein said means for transmitting comprises at least one infrared transmitter.

11. The apparatus of claim 10 wherein said means for transmitting further comprises a plurality of infrared transmitters positioned on said television receiver to transmit simultaneously in a plurality of directions.

12. The apparatus of claim 10 wherein said infrared transmitter is enclosed in a dome mounted on said television receiver.

13. The apparatus of claim 10 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said television receiver and wherein said mouse is placed near said means for recording.

14. The apparatus of claim 10 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said television receiver and wherein said mouse is placed near said means for channel selection.

15. The apparatus of claim 10 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said television receiver and wherein said miniature mouse is placed near said means for recording.

16. The apparatus of claim 10 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said television receiver and wherein said miniature mouse is placed near said means for channel selection.

17. The apparatus of claim 1 that further comprises:
means for advancing time-of-day commands decoded from a compressed code by a predetermined time interval; and
means for retarding time-of-day commands decoded from a compressed code by a predetermined time interval.

18. The apparatus for using compressed codes for recorder preprogramming of claim 1 that further comprises:
means for storing a plurality of protocol sets of record the channel select transmit signals coupled to said means for transmitting;
means for selecting one of said protocol sets of record transmit signals; and
means for selecting one of said protocol sets of channel select transmit signals.

19. An apparatus for using compressed codes for recorder preprogramming that comprises:
a video cassette recorder;
means for entering into said video cassette recorder compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
said video cassette recorder comprising:
means for decoding each compressed code into the combination of channel, date, time-of-day and length commands,
means for storing said combinations of channel, date, time-of-day and length commands,
a clock with an output as a function of time,
means for recording said combinations of channel, time-of-day, date and length commands in said means for storing into temporal order, and
means for comparing the date and time-of-day commands of the temporally earliest in time combination in said means for storing to the output of the clock for a predetermined relation;
wherein said video cassette recorder begins recording after the predetermined relationship is found to exist according to the date and time-of-day commands of said temporally earliest in time combination;
means for channel selection;
means for transmitting channel select commands to said means for channel selection after the predetermined relation is found to exist according to the channel command of said temporally earliest in time combination wherein said means for transmitting is coupled to said video cassette recorder; and
wherein said video cassette recorder stops recording following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.

20. The apparatus of claim 19 wherein said means for entering comprises a video cassette recorder remote controller.

21. The apparatus of claim 19 wherein said means for entering comprises controls coupled to said video cassette recorder.

22. The apparatus of claim 19 wherein said means for channel selection comprises a cable box.

23. The apparatus of claim 19 wherein said means for channel selection comprises a satellite receiver.

24. The apparatus for using compressed codes for recorder preprogramming of claim 19 which further comprises means for substituting a local channel number for a channel number in at least one said channel command.

25. The apparatus of claim 19 further comprising means for selecting a periodicity for repeating the operation of said means for.

26. The apparatus of claim 19 further comprising a means for warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in time combination.

27. The apparatus of claim 19 wherein said means for transmitting comprises at least one infrared transmitter.

28. The apparatus of claim 27 wherein said means for transmitting further comprises a plurality of infrared transmitters positioned on said television receiver to transmit simultaneously in a plurality of directions.

29. The apparatus of claim 27 wherein said infrared transmitter is enclosed in a dome mounted on said video cassette recorder.

30. The apparatus of claim 27 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said video cassette recorder and wherein said mouse is placed near said means for channel selection.

31. The apparatus of claim 27 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said video cassette recorder and wherein said miniature mouse is placed near said means for channel selection.

32. The apparatus of claim 19 that further comprises:
means for advancing time-of-day commands decoded from a compressed code by a predetermined time interval; and
means for retarding time-of-day commands decoded from a compressed code by a predetermined time interval.

33. The apparatus for using compressed codes for recorder preprogramming of claim 19 that further comprises:
means for storing a plurality of protocol sets of record and channel select transmit signals coupled to said means for transmitting; and
means for selecting one of said protocol sets of channel select transmit signals.

34. An apparatus for using compressed codes for recorder preprogramming that comprises:
a cable box;
means for entering into said cable box compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
said cable box comprising:
means for decoding each compressed code into the combination of channel, date, time-of-day and length commands,
means for storing said combinations of channel, date, time-of-day and length commands,
a clock with an output as a function of time,
means for reordering said combinations of channel, time-of-day, date and length commands in said means for storing into temporal order, and
means for comparing the date and time-of-day commands of the temporally earliest in time combination in said means for storing to the output of the clock for a predetermined relation;
means for recording;
means for transmitting record on commands to said means for recording after the predetermined relation is found to exist according to the date and time-of-day commands of said temporally earliest in time combinations wherein said means for transmitting is coupled to said cable box;
means for channel selection;
wherein said means for transmitting transmit channel select commands to said means for channel selection after the predetermined relation is found to exist wherein said means for transmitting is coupled to said cable box; and
wherein said means for transmitting transmit record off commands to said means for recording following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.

35. The apparatus of claim 34 wherein said means for entering comprises a cable box remote controller.

36. The apparatus of claim 34 wherein said means for entering comprises controls coupled to said cable box.

37. The apparatus of claim 34 wherein said means for channel selection comprises a satellite receiver.

38. The apparatus of claim 34 wherein said means for channel selection comprises a cable box.

39. The apparatus of claim 34 wherein said means for recording comprises a video cassette recorder.

40. The apparatus for using compressed codes for recorder preprogramming of claim 34 which further comprises means for substituting a local channel number for a channel number in at least one said channel command.

41. The apparatus of claim 34 further comprising means for selecting a periodicity for repeating the operation of said means for.

42. The apparatus of claim 34 further comprising a means for warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in time combination.

43. The apparatus of claim 34 wherein said means for transmitting comprises at least one infrared transmitter.

44. The apparatus of claim 43 wherein said means for transmitting further comprises a plurality of infrared transmitters positioned on said television receiver to transmit simultaneously in a plurality of directions.

45. The apparatus of claim 43 wherein said infrared transmitter is enclosed in a dome mounted on said cable box.

46. The apparatus of claim 43 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said cable box and wherein said mouse is placed near said means for recording.

47. The apparatus of claim 43 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said cable box and wherein saidmouse is placed near said means for channel selection.

48. The apparatus of claim 43 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said cable box and wherein said miniature mouse is placed near said means for recording.

49. The apparatus of claim 43 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said cable box and wherein said miniature mouse is placed near said means for channel selection.

50. The apparatus of claim 34 that further comprises:
means for advancing time-of-day command decoded from a compressed code by a predetermined time interval; and
means for retarding time-of-day commands decoded from a compressed code by a predetermined time interval.

51. The apparatus for using compressed codes for recorder preprogramming of claim 34 that further comprises:
means for storing a plurality of protocol sets of record and channel select transmit signals coupled to said means for transmitting;
means for selecting one of said protocol sets of record transmit signals; and
means for selecting one of said protocol sets of channel select transmit signals.

52. An apparatus for using compressed codes for recorder preprogramming that comprises:
a satellite receiver;
means for entering into said satellite receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
said satellite receiver comprising:
means for decoding each compressed code into the combination of channel, date, time-of-day and length commands,
means for storing said combination of channel, date, time-of-day and length commands,
a clock with an output as a function of time,
means for reordering said combinations of channel, time-of-day, date and length commands in said means for storing into temporal order, and
means for comparing the date and time-of-day commands of the temporally earliest in time combination in said means for storing to the output of the clock for a predetermined relation;
means for recording;
means for transmitting record on commands to said means for recording after the predetermined relation is found to exist according to the date and time-of-day commands of said temporally earliest in time combination, wherein said means for transmitting is coupled to said satellite receiver;
means for channel selection;
wherein said means for transmitting transmit channel select commands to said means for channel selection after the predetermined relation is found to exist wherein said means for transmitting is coupled to said satellite receiver; and
wherein said means for transmitting transmit record off commands to said means for recording following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.

53. The apparatus of claim 52 wherein said means for entering comprises a satellite receiver remote controller.

54. The apparatus of claim 52 wherein said means for entering comprises controls coupled to said satellite receiver.

55. The apparatus of claim 52 wherein said means for channel selection comprises a cable box.

56. The apparatus of claim 52 wherein said means for channel selection comprises a satellite receiver.

57. The apparatus of claim 52 wherein said means for recording comprises a video cassette recorder.

58. The apparatus for using compressed codes for recorder preprogramming of claim 52 which further comprises means for substituting a local channel number for a channel number in at least one said channel command.

59. The apparatus of claim 52 further comprising means for selecting a periodicity for repeating the operation of said means for.

60. The apparatus of claim 52 further comprising a means for warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in time combination.

61. The apparatus of claim 52 wherein said means for transmitting comprises at least one infrared transmitter.

62. The apparatus of claim 61 wherein said means for transmitting further comprises a plurality of infrared transmitters positioned on said television receiver to transmit simultaneously in a plurality of directions.

63. The apparatus of claim 61 wherein said infrared transmitter is enclosed in a dome mounted on said satellite receiver.

64. The apparatus of claim 61 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said satellite receiver and wherein said mouse is placed near said means for recording.

65. The apparatus of claim 61 further comprising a mouse wherein said infrared transmitter is enclosed in said mouse and wherein said mouse is attached via a cable to said satellite receiver and wherein said mouse is placed near said means for channel selection.

66. The apparatus of claim 61 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said satellite receiver and wherein said miniature mouse is placed near said means for recording.

67. The apparatus of claim 61 further comprising a miniature mouse wherein said infrared transmitter is enclosed in said miniature mouse and wherein said miniature mouse is attached via a cable to said satellite receiver and wherein said miniature mouse is placed near said means for channel selection.

68. The apparatus of claim 52 that further comprises:
means for advancing time-of-day commands decoded from a compressed code by a predetermined time interval; and
means for retarding time-of-day commands decoded from a compressed code by a predetermined time interval.

69. The apparatus for using compressed codes for recorder preprogramming of claim 52 that further comprises:
means for storing a plurality of protocol sets of record and channel select transmit signals coupled to said means for transmitting;
means for selecting one of said protocol sets of record transmit signals; and
means for selecting one of said protocol sets of channel select transmit signals.

70. A method of permitting programs to be preprogrammed for recording by a recorder for time shifted viewing comprising:
providing a television receiver having a means for transmitting signals and a clock with an output as a function of time;
entering into said television receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
decoding each compressed code to obtain channel, time-of-day, date and length commands;
providing a memory;
storing each said channel, time-of-day, date and length commands into said memory;
recording said channel, time-of-day, date and length commands in said memory into temporal order;
comparing the date and time-of-day commands of the temporally earliest in time entry in said memory to the output of the clock for a predetermined relation;
transmitting channel and record on commands from said television receiver after the predetermined relationship is found to exist;
selecting the channel;
recording the program;
measuring length of time from transmitting record on command; and
transmitting record off commands from said television receiver when the measured length of time compares with said length command.

71. A method of permitting programs to be preprogrammed for recording by a recorder for time shifted viewing comprising:
providing a video cassette recorder having a means for transmitting signals and a clock with an output as a function of time;
entering into said video cassette recorder compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
decoding each compressed code to obtain channel, time-of-day, date and length commands;
providing a memory;
storing each said channel, time-of-day, date and length commands in said memory into said memory;
reordering said channel, time-of-day, date and length commands in said memory into temporal order;
comparing the date and time-of-day commands of the temporally earliest in time entry in said memory to the output of the clock for a predetermined relation;
transmitting channel commands from said video cassette recorder after the predetermined relationship is found to exist;
selecting the channel;
recording the program when predetermined relation is found to exist;
measuring length of time from start of recording; and
stopping recording when the measured length of time compares with said length command.

72. A method of permitting programs to be preprogrammed for recording by a recorder for time shifted viewing comprising:
providing a cable box having a means for transmitting signals and a clock with an output as a function of time;
entering into said cable box compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
decoding each compressed code to obtain channel, time-of-day, date and length commands;
providing a memory;
storing each said channel, time-of-day, date and length commands into said memory;
reordering said channel, time-of-day, date and length commands in said memory into temporal order;
comparing the date and time-of-day commands of the temporally earliest in time entry in said memory to the output of the clock for a predetermined relation;
transmitting channel and record on commands from said cable box after the predetermined relationship is found to exist;
selecting the channel;
recording the program;
measuring length of time from transmitting record on command; and
transmitting record off commands from said cable box when the measured length of time compares with said length command.

73. A method of permitting program to be preprogrammed for recording by a recorder for time shifted viewing comprising:
providing a satellite receiver having a means for transmitting signals and a clock with an output as a function of time;
entering into said satellite receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
decoding each compressed code to obtain channel, time-of-day, date and length commands;
providing a memory;
storing each said channel, time-of-day, date and length commands into said memory;
reordering said channel, time-of-day, date and length commands in said memory into temporal order;
comparing the date and time-of-day commands of the temporally earliest in time entry in said memory to the output of the clock for a predetermined relation;
transmitting channel and record on commands from said satellite receiver after the predetermined relationship is found to exist;
selecting the channel;
recording the program;
measuring length of time from transmitting record on command; and
transmitting record off commands from said satellite receiver when the measured length of time compares with said length command.

74. The method of claim 70, 71, 72 or 73 wherein the step of selecting and recording are performed by a video cassette recorder.

75. The method of claim 70, 71, 72 or 73 wherein the step of selecting is performed by a cable box.

76. The method of claim 70, 71, 72 or 73 wherein the step of selecting is performed by a satellite receiver.

77. The method of claim 70, 71, 72 or 73 which further comprises the step of advancing said time-of-day command by a predetermined number of hours.

78. The method of claim 70, 71, 72 or 73 which further comprises the step of retarding said time-of-day command by a predetermined number of hours.

79. The method of claim 70, 71, 72 or 73 wherein the step of transmitting is performed by an infrared transmitter.

80. The method of claim 70, 71, 72 or 73 wherein the step of transmitting is performed by an infrared transmitter attached to a cable.

81. The method of claim 70, 71, 72 or 73 which further comprises the step of:
selecting a periodicity for repeating the step of recording on a channel corresponding to said channel command at a time-of-day corresponding to said time-of-day command and for a length corresponding to said length command.

82. The method of claim 70, 71, 72 or 73 wherein the step of entering is performed by a television remote.

83. The method of claim 70, 71, 72 or 73 which further comprises the step of:
warning a user that said clock output will compare within a preset time to said date and time-of-day commands.

84. The method of claim 70, 71, 72 or 73 which further comprises the step of:
substituting a local channel number for a channel number in said channel command.

85. The method of claim 70, 71, 72 or 73 which further comprises the steps of:
storing a plurality of protocol sets of transmit signals; and
selecting a protocol set of transmit signals for a particular means for recording.

86. The method of claim 70, 71, 72 or 73 wherein the step of decoding each compressed code to obtain channel, time-of-day, date and length commands comprises the step of:
converting said compressed code into a binary number;
recording the bits in said binary number to obtain a reordered binary compressed code;
grouping said reordered binary compressed code into channel, date, time and length priority numbers; and
deriving said channel, day, time-of-day and length commands from said channel, date, time and length priority numbers.

87. The method of claim 86 wherein the steps of reordering comprises the step of performing said reordering as a function of the output of a clock.

88. The method of claim 86 wherein the step of deriving comprises the step of performing said deriving as a function of the output of a clock.

89. The method of claim 70, 71, 72 or 73 wherein the step of decoding each compressed code to obtain channel, time-of-day, date and length commands comprises the steps of:
converting said compressed code into a mixed radix number;
reordering the bits in said mixed radix number to obtain a reordered mixed radix compressed code;
grouping said reordered mixed radix compressed code into channel, date, time and length priority numbers; and
deriving said channel, day, time-of-day and length commands from said channel, date, time and length priority numbers.

90. An apparatus for using compressed codes for recorder preprogramming that comprises:
a television receiver;
means for entering into said television receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
said television receiver comprising:
means for decoding each compressed code into the combination of channel, date, time-of-day and length commands,
means for storing said combinations of channel, date, time-of-day and length commands,
a clock with an output as a function of time,
means for reordering said combinations of channel, time-of-day, date and length commands in said means for storing into temporal order, and
means for comparing said ate and time-of-day commands of the temporally earliest in time program entry in said means for storing to the output of the clock for a predetermined relation;
means for transmitting channel select and record on commands to a recorder after the predetermined relationship is found to exist according to the channel, date and time-of-day command of said temporally earliest in time combination, wherein said means for transmitting is coupled to said television receiver; and
wherein said means for transmitting transmits record off commands following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.

91. The apparatus of claim 90 wherein said means for entering comprises a television remote control.

92. The apparatus of claim 90 wherein said means for entering comprises controls coupled to said television receiver.

93. The apparatus of claim 90 which further comprises:
a channel selector responsive to said transmitted channel select commands; and
a means for recording the program responsive to said transmitted record on and record off commands.

94. The apparatus of claim 93 wherein said channel selector comprises a cable box.

95. The apparatus of claim 93 wherein said means for recording comprises a video cassette recorder.

96. The apparatus for using compressed codes for recorder preprogramming of claim 90 which further comprises means for substituting a local channel number for a channel number in at least one of said channel commands.

97. The apparatus of claim 90 further comprising means for selecting a periodicity for repeating the operation of said means for transmitting.

98. The apparatus of claim 90 further comprising a means for warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in time combination.

99. The apparatus of claim 90 wherein said means for transmitting further comprises means for transmitting simultaneously in a plurality of directions.
100. The apparatus of claim 90 or 99 wherein said means for transmitting comprises at least one infrared transmitter.
101. The apparatus of claim 90 that further comprises:
means for advancing time-of-day commands decoded from a compressed code by a predetermined time interval; and
means for retarding time-of-day commands decoded from a compressed code by a predetermined time interval.
102. The apparatus for using compressed codes for recorder preprogramming of claim 90 that further comprises:
means for storing a plurality of protocol sets of transmit signals coupled to said means for transmitting; and
means for selecting one of said protocol sets of transmit signals.
103. A method of permitting programs to be preprogrammed for recording by a recorder for time shifted viewing comprising:
providing a television receiver having a decoder, a memory, means for transmitting signals to the recorder and a clock with an output as a function of time;
entering into said television receiver compressed codes each having at least one digit and each representative of, and compressed in length from, the combination of channel, time-of-day, date and length commands for a program;
decoding each compressed code into the combination of channel, time-of-day, date and length commands with said decoder;
storing each said combination of said channel, time-of-day, date and length commands into said memory;
reordering said combinations of channel, time-of-day, date and length commands in said memory into temporal order;
comparing the date and time-of-day commands of the temporally earliest in time combination in said memory to the output of the clock for a predetermined relation;
transmitting channel select and record on commands from said television receiver to the recorder after the predetermined relation is found to exist according to the channel, date and time-of-day commands of the temporally earliest in time combination; and
transmitting record off commands from said television receiver to the recorder following an elapsed time interval corresponding to the length command of said temporally earliest in time combination.
104. The method of claim 103 further comprising the steps of selecting a channel and recording a program corresponding to said temporally earliest in time combination and wherein the steps of selecting and recording are performed by a video cassette recorder.
105. The method of claim 103 further comprising the steps of selecting a channel corresponding to said temporally earliest in time combination and wherein the steps of selecting is performed by a cable box.
106. The method of claim 103 which further comprises the step of advancing said time-of-day commands by a predetermined time interval.
107. The method of claim 103 which further comprises the step of retarding time-of-day commands by a predetermined time interval.
108. The method of claim 103 wherein the steps of transmitting further comprise the step of transmitting simultaneously in a plurality of directions.
109. The method of claim 103 which further comprises the step of selecting a periodicity for repeating the steps of transmitting.
110. The method of claim 103 wherein the step of entering is performed by a television remote.
111. The method of claim 103 wherein the step of entering is performed by controls coupled to said television receiver.
112. The method of claim 103 which further comprises the step of warning a user that said clock output will compare within a preset time to said date and time-of-day commands of said temporally earliest in time combination.
113. The method of claim 103 which further comprises the step of substituting a local channel number for a channel number in at least one of said channel commands. PG,85
114. The method of claim 103 which further comprises the step of:
storing a plurality of protocol sets of transmit signals; and
selecting one of said protocol sets of transmit signals.
115. The method of claim 103 wherein the step of decoding each compressed code to obtain channel, time-of-day, date and length commands comprises the steps of:
converting each said compressed code into a binary number;
reordering the bits in said binary number to obtain a reordered binary compressed code;
grouping said reordered binary compressed code into channel, date, time and length priority numbers; and
deriving said combination of channel, date, time-of-day and length commands from said channel, date, time and length priority numbers.
116. The method of claim 115 wherein the step of reordering comprises the step of performing said reordering as a function of the output of a clock.
117. The method of claim 115 wherein the step of deriving comprises the step of performing said deriving as a function of the output of a clock.
118. The method of claim 103 wherein the step of decoding each compressed code to obtain channel, time-of-day, date and length commands comprises the steps of:
converting each said compressed code into a mixed radix number comprising bits;
reordering the bits in said mixed radix number to obtain a reordered mixed radix compressed code;
grouping said reordered mixed radix compressed code into channel, date, time and length priority numbers; and
deriving said combination of channel, date, time-of-day and length commands from said channel, date, time and length priority numbers.
Description
FIELD OF THE INVENTION

This invention relates generally to video cassette recorder systems and particularly to the timer preprogramming feature of video cassette recorders (VCRs) and to an apparatus and method for using encoded information to shorten the time required to perform timer preprogramming and an apparatus and method of embedding the decoding of the encoded information in a television receiver, video cassette recorder, cable box and satellite receiver.

PRIOR ART

The video cassette recorder (VCR) has a number of uses, including playing back of tapes filmed by a video camera, playing back of pre-recorded tapes, and recording and playing back of broadcast and cable television programs.

To record a television program in advance of viewing it, a two-step process is often used: (1) obtain the correct channel, date, time and length (CDTL) information from a television program guide, and (2) program this CDTL information into the VCR. Depending on the model, year and type of the VCR, the CDTL information can be programmed in various ways including: (i) pushing an appropriate sequence of keys in the console according to instructions contained in the user's manual, (ii) pushing an appropriate sequence of keys in a remote hand-held control unit according to instructions contained in the user's manual (remote programming), and (iii) executing a series of keystrokes in the remote hand-held control unit in response to a menu displayed on the television screen (on-screen programming). Other techniques for timer preprogramming have been suggested including: (iv) reading in certain bar-code information using a light pen (light pen programming), and (v) entering instructions through a computer or telephone modem. These various methods differ only in the physical means of specifying the information while the contents, being CDTL and certain power/clock/timer on-off commands are generally common although the detailed protocol can vary with different model VCRs. Methods (i) and (ii) described above can require up to 100 keystrokes, which has inhibited the free use of the timer preprogramming feature of VCRs. To alleviate this, new VCR models have included an "On-Screen Programming" feature, which permits remote input of CDTL information in response to a menu displayed on the television screen. Generally on screen programming of CDTL information requires an average of about 18 keystrokes, which is less than some of the prior methods but still rather substantial. Some of the other techniques such as (iv) above, require the use of special equipment such as a bar code reader.

In general the present state of the art suffers from a number of drawbacks. First, the procedure for setting the VCR to record in advance can be quite complex and confusing and difficult to learn; in fact, because of this many VCR owners shun using the timer preprogramming record feature. Second, the transcription of the CDTL information to the VCR is hardly ever error-free; in fact, many users of VCR's timer preprogramming features express concern over the high incidence of programming errors. Third, even for experienced users, the process of entering a lengthy sequence of information on the channel, date, time and length of desired program can become tedious. Fourth, techniques such as reading in bar-code information or using a computer require special equipment. These drawbacks have created a serious impedance in the use of a VCR as a recording device for television programs. The effect is that time shifting of programs has not become as popular as it once was thought it would be. Accordingly, there is a need in the art for a simpler system for effecting VCR timer preprogramming which will enable a user to take advantage of the recording feature of a VCR more fully and freely.

SUMMARY OF THE INVENTION

A principal object of the invention is to provide an improved system for the selection and entering of channel, date, time and length (CDTL) information required for timer preprogramming of a VCR which is substantially simpler, faster and less error-prone than present techniques. Another principal object of the invention is to provide televisions having an embedded capability for timer programming control.

In accordance with the invention, to program the timer preprogramming feature of a video system, there is an apparatus and method for using encoded video recorder/player timer preprogramming information. The purpose is to significantly reduce the number of keystrokes required to set up the timer preprogramming feature on a VCR. In accordance with this invention it is only necessary for the user to enter a code with 1 to 7 digits or more into the VCR. This can be done either remotely or locally at the VCR. Built into either the remote controller or the VCR is a decoding means which automatically converts the code into the proper CDTL programming information and activates the VCR to record a given television program with the corresponding channel, date, time and length. Generally multiple codes can be entered at one time for multiple program selections. The code can be printed in a television program guide in advance and selected for use with a VCR or remote controller with the decoding means.

Another principal object of the invention is to embed the decoding means into a television. The television would then at the appropriate time distribute the proper commands to a VCR and a cable box to record the desired program. The user would use the television remote or controls on the television to enter the code that signifies the program to be recorded. The same television remote and controls on the television would also be used to perform normal television control functions, such as channel selection. When the codes are entered they are transmitted to the television and the decoder in the television, which decodes the codes into CDTL information and then the codes themselves and the CDTL information could be displayed "on screen" so that the user can verify that the proper codes have been entered. Then at the appropriate time the television would transmit the proper commands to a VCR and a cable box, if necessary, to command the recording of the selected program. This control function can be carried out by using an infrared link by placing infrared transmitters on the television cabinet, preferably at the corners. The television circuitry would include the capability of storing or learning the infrared code protocols for the VCR and the cable box.

Another principal object of the invention is to embed the decoding means into various equipments associated with television, such as a video cassette recorder, cable box or satellite receiver. In any system the decoding means would only have to be present in one of the equipments, such as the cable box, which would then at the appropriate time distribute the proper commands to the other equipments such as a VCR and a satellite receiver to record the desired program. The user would use the television remote or controls on the equipment with the decoder to enter the code that signifies the program to be recorded. The same television remote would also be used to perform normal television control functions, such as channel selection. When the codes are entered they are transmitted to the equipment with the decoder, which decodes the codes into CDTL information. Then at the appropriate time the equipment with the decoder would transmit the proper commands to a the other equipment such as a VCR, satellite receiver and a cable box to command the recording of the selected program. This control function can be carried out by using an infrared link by coupling infrared transmitters on the equipment with the decoder. The infrared transmitter can be placed in a infrared dome on the equipment, mounted behind the front panel, attached to a mouse coupled via a cable to the equipment with the decoder with the mouse placed near the receiver, or attached to a stick on miniature mouse coupled via a cable to the equipment with the decoder with the miniature mouse attached to the device with the receiver. The equipment with the decoder would include the capability of storing or learning the infrared code protocols for the other equipment, such as a VCR, satellite receiver and a cable box.

Other objects and many of the attendant features of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed descriptions and considered in connection with the accompanying drawings in which like reference symbols designate like parts throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic showing apparatus according to this invention with the code decoder means embedded in the video cassette recorder.

FIG. 2 is a schematic of the VCR embedded processors for command control and code decoding.

FIG. 3 is a schematic showing a preferred embodiment according to this invention with the code decoder means embedded in a remote controller.

FIG. 4 is a schematic of the processor embedded in the remote controller.

FIG. 5 is a schematic of a universal remote controller with the code decoder means embedded in the universal remote controller.

FIG. 6 is a flow graph of the G-code decoding technique.

FIG. 7 is a flow graph of the G-code encoding technique

FIG. 8 is an illustration of part of a television calendar according to this invention.

FIG. 9 is a flowchart for decoding for cable channels.

FIG. 10 is a flowchart for encoding for cable channels.

FIG. 11 is a flow graph of the G-code decoding for cable channels including conversion from assigned cable channel number to local cable carrier channel number.

FIG. 12 is a means for decoding including a stack memory.

FIG. 13 is a flowchart for program entry into stack memory.

FIG. 14 is an operation flowchart for sending programs from remote control to main unit VCR.

FIG. 15 is a perspective view of an apparatus for using compressed codes for recorder prepregramming according to a preferred embodiment of the invention.

FIG. 16 is a front view of the apparatus of FIG. 15 showing a forward facing light emitting diode.

FIG. 17 is a perspective view of the apparatus of FIG. 15 placed in a mounting stand.

FIG. 17A is a front elevational view of the apparatus of FIG. 15 placed in the mounting stand as shown in FIG. 17.

FIG. 18 is a detail of the LCD display of the apparatus of FIG. 15.

FIG. 19 is a perspective view showing a manner of placing the apparatus of FIG. 15 relative to a cable box and a VCR.

FIG. 20 is a perspective view showing a manner of placing the mounting stand with the apparatus of FIG. 15 mounted thereon near a cable box and VCR.

FIG. 21 is a schematic showing apparatus for using compressed codes for recorder prepregramming according to a preferred embodiment of the invention.

FIG. 22 is a detailed schematic showing a preferred embodiment of apparatus implementing the schematic of FIG. 21.

FIG. 23 is a flow graph for program entry into the apparatus of FIG. 15.

FIG. 24 is a flow graph for review and program cancellation of programs entered into the apparatus of FIG. 15.

FIG. 25 is a flow graph for executing recorder prepregramming using compressed codes according to a preferred embodiment of the invention.

FIG. 26 is a flow graph for encoding program channel, date, time and length information into decimal compressed codes.

FIG. 27 is a flow graph for decoding decimal compressed codes into program channel, date, time and length information.

FIG. 28 is an embodiment of an assigned channel number/local channel number table.

FIG. 29 block diagram of a system including a television having a G-code decoder.

FIG. 30 is a schematic of a television having a G-code decoder.

FIG. 31 is a schematic showing apparatus for a G-code decoder in a television having G-code decoding.

FIG. 32 is a block diagram of a system including a television having a G-code decoder, a VCR, a cable box and a satellite receiver.

FIG. 33 is a block diagram of a system including a VCR having a G-code decoder, a television, a cable box and a satellite receiver.

FIG. 34 is a block diagram of a system including a cable box having a G-code decoder, a television, a VCR, and a satellite receiver.

FIG. 35 is a block diagram of a system including a satellite receiver having a G-code decoder, a television, a VCR, and a cable box.

FIG. 36 is a perspective view showing a cable box placed on top of a VCR having an infrared transmitter behind the front panel which communicates to the cable box infrared receiver via reflection.

FIG. 37 is a perspective view showing a cable box placed on top of a VCR having an infrared transmitter inside a infrared dome on the top of the VCR which communicates to the cable box infrared receiver.

FIG. 38 is a perspective view of a VCR having an infrared transmitter inside a mouse coupled via a cable to the VCR with the mouse placed near the cable box infrared receiver.

FIG. 39 is a perspective view of a VCR having an infrared transmitter inside a miniature mouse coupled via a cable to the VCR with the miniature mouse stuck onto the cable box near the infrared receiver.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and more particularly, to FIG. 1, there is shown an apparatus for using encoded video recorder/player timer preprogramming information 10 according to this invention. The primary components include a remote controller 12 and a video cassette recorder/player with G-code decoder 14, which can be controlled by remote controller 12 via a command signal 16. The remote controller 12 can have a number of keys, which include numerical keys 20, G-code switch 22, function keys 24, program key 26 and power key 27. There are means in the remote controller 12 that interprets each key as it is pressed and sends the proper command signal 16 to the VCR via an infra-red light emitting diode 28. Except for the G-code switch 22 on the remote controller 12 in FIG. 1, the remote controller 12 is essentially the same as any other remote controller in function. The G-code switch 22 is provided just to allow the user to lock the remote controller 12 in the G-code mode while using a G-code, which is the name given to the compressed code which is the encoded CDTL information, to perform timer preprogramming.

A G-code consists of 1 to 7 digits, although more could be used, and is associated with a particular program. A user would lookup the G-code in a program guide and just enter the G-code on the remote controller 12, instead of the present state of the art, which requires that the user enter the actual channel, date, time and length (CDTL) commands.

In order to understand the advantages of using a G-code, it is helpful to describe the best of the current state of the art, which is "on screen programming" with direct numerial entry. This technique involves about 18 keystrokes and the user has to keep switching his view back and forth between the TV screen and the remote controller while entering the CDTL information. This situation may be akin to a user having to dial an 18 digit telephone number while reading it from a phone book. The number of keys involved and the switching back and forth of the eye tend to induce errors. A typical keying sequence for timer recording using on-screen CDTL programming is as follows:

The first program (PROG) key 26 enters the programming mode. Then a sequence of numericals key 20 are pushed. The 2 means it is timer recording rather than time setting. The 1 means the user is now entering the settings for program 1. The 15
is the date. The 07 is starting hour. The 30 is a starting minute. The 2 means pm. The next sequence 08 00 2 is the stopping time. The 04 is channel number. Finally, the PROG is hit again to exit the program mode.

By contrast, this command could have been "coded" and entered in a typical G-code sequence as follows: PROG 113 PROG. To distinguish that the command is a coded G-code, the G-code switch 22 should be turned to the "ON" position. Instead of having a switch, a separate key "G" can be used. The G-code programming keystroke sequence would then be: G 1138 PROG.

The use of a G-code does not preclude "on-screen" confirmation of the program information that has been entered. When the keystrokes "PROG 1138 PROG" are entered with the G-code switch in the "ON" position, the G-code would be decoded and the television could display the following message:

______________________________________ START STOP PROGRAM DATE TIME TIME CHANNEL ______________________________________ 1138 15 7:30 PM 8:00 PM 4 ______________________________________

In order for the G-code to be useful it must be decoded and apparatus for that purpose must be provided. Referring to FIG. 1, a video cassette recorder/player with G-code decoder 14 is provided to be used in conjunction with remote controller
12. The command signal 16 sent from the remote controller 12 is sensed by the photodiode 32 and converted to electrical signals by command signal receiver 30. The electrical signals are sent to a command controller 36, which interprets the commands and determines how to respond to the commands. As shown in FIG. 1, it is also possible for the command controller 36 to receive commands from the manual controls 34 that are normally built into a VCR. If the command controller 36 determines that a G-code was received then the G-code will be sent to the G-code decoder 38 for decoding. The G-code decoder 38 converts the G-code into CDTL information, which is used by the command controller 36 to set the time/channel programming 40. Built into the VCR is a clock 42. This is normally provided in a VCR and is used to keep track of the date and time. The clock 42 is used primarily by the time/channel programming 40 and the G-code decoder 38 functions. The time/channel programming 40 function is set up with CDTL information by the command controller 36. When the proper date and time is read from clock 42, then the time/channel programming 40 function turns the record/playback 44 function "ON" to record. At the same time the tuner 46 is tuned to the proper channel in the television signal 18. Later the user can command the record/playback 44 function to a playback mode to watch the program via the television monitor 48.

An alternate way to control the recorder is to have the command controller 36 keep all the CDTL information instead of sending it to the time/channel programming 40. The command controller would also keep track of the time by periodically reading clock 42. The command controller would then send commands to the time/channel programming 40 to turn on and off the recorder and to tuner 46 to cause it to tune to the right channel at the right time according to the CDTL information.

The clock 42 is also an input to G-code decoder 38, which allows the G-code decoding to be a function of the clock, which lends a measure of security to the decoding technique and makes it harder to copy. Of course this requires that the encoding technique must also be a function of the clock.

A possible realization of the command controller 36 and the G-code decoder 38 is shown in FIG. 2. The command controller 36 function can be realized with a microprocessor 50, a random access memory 52 and a read only memory 54, which is used for program storage. The input/output 56 function is adapted to receive commands from the command signal receiver 30, the manual controls 34 and the clock 42, and to output signals to a display 35, the clock 42, and the time/channel programming 40 function. If the microprocessor 50 interprets that a G-code has been received, than the G-code is sent to microcontroller 60 for decoding. The microcontroller 60 has an embedded random access memory 62 and an embedded read only memory 64 for program and table storage. The clock 42 can be read by both microprocessor 50 and microcontroller 60.

An alternative to having microcontroller 60 perform the G-code decoding is to build the G-code decoding directly into the program stored in read only memory 54. This would eliminate the need for microcontroller 60. Of course, other hardware to perform the G-code decoding can also be used. The choice of which implementation to use is primarily an economic one.

The blocks in FIGS. 1 and 2 are well known in the prior art and are present in the following patents: Fields, U.S. Pat. No. 4,481,412; Scholz, U.S. Pat. No. 4,519,003; and Brugliera, U.S. Pat. No. 4,631,601. For example, clock 42 is analogous to element 7 in Scholz and element 17 in Brugliera. Other analogous elements are: command signal receiver 30 and Scholz 14 and Brugliera 12; tuner 46 and Scholz 6 and Brugliera 10; time/channel programming 40 and Scholz 8, 11 and Brugliera 16; record & playback 44 and Scholz 1, 2, 4; command controller 36 and Scholz 11, 10 and Brugliera 12; microprocessor 50 and Fields 27; RAM 62 and Fields 34; ROM 54 and Fields 33; manual controls 34 and Scholz 15, 16; and remote controller 12 and Scholz 26
and Bruqliera 18.

FIG. 3 illustrates an alternate preferred embodiment of this invention. In FIG. 3 a remote controller with embedded G-code decoder 80 is provided. The remote controller with embedded G-code decoder 80 is very similar to remote controller 12, except for the addition of the G-code decoder 82. Note that it is also possible in any remote controller to provide a display 84. The remote controller with embedded G-code decoder 80 would be used in conjunction with a normal video cassette recorder/player 70, which would not be required to have an embedded G-code decoder. The numerals for the subelements of video cassette recorder/player 70 are the same as described above for the video cassette recorder/player with G-code decoder 14 and have the same function, except for the absence of G-code decoder 38. This preferred embodiment has the advantage that it can be used in conjunction with VCRs that are presently being used. These do not have a G-code decoding capability. Replacing their remote controllers with ones that have this capability built-in can vastly improve the capability to do timer preprogramming for a modest cost.

FIG. 4 illustrates a possible realization of the G-code decoder 82 built into the remote controller with embedded G-code decoder 80. A microprocessor 60 can be used as before to decode the G-code, as well as interface with the display 84, a clock 85, the keypad 88 and the light emitting diode 28. Alternately, other hardware implementations can be used to perform the G-code decoding. The clock 85 is provided in the remote controller 80 so that the G-code decoder 82 can be made to have the clock 85 as one of its inputs. This allows the G-code decoding to be a function of the clock 85, which lends a measure of security to the decoding technique and makes it harder to copy.

The remote controller with embedded G-code decoder as described above would send channel, date, time and length information to the video cassette recorder/player 70, which would use the CDTL information for tuning into the correct channel and starting and stopping the recording function. The remote controller may have to be unique for each different video cassette recorder/player, because each brand or model may have different infrared pulses for each type of information sent such as the channel number keys and start record and stop record keys. The particular infrared pulses used for each key type can be called the vocabulary of the particular remote controller. Each model may also have a different protocol or order of keys that need to be pushed to accomplish a function such as timer preprogramming. The protocol or order of keys to accomplish a function can be called sentence structure. If there is a unique remote controller built for each model type, then the proper vocabulary and sentence structure can be built directly into the remote controller.

An alternate to having the remote controller with embedded G-code decoder send channel, date, time and length information to the video cassette recorder/player 70, is to have the remote controller with embedded G-code decoder perform more operations to simplify the interfacing problem with existing video cassette recorder/players. In particular, if the remote controller not only performs the G-code decoding to CDTL, but also keeps track of time via clock 85, then it is possible for the remote controller to send just channel, start record and stop commands to the video cassette recorder/player. The channel, start and stop are usually basic one or two key commands, which means there is no complicated protocol or sentence structure involved. Thus, to communicate with a diverse set of video cassette recorder/player models it is only necessary to have memory within the remote controller, such as ROM 64 of FIG. 4, for storing the protocol for all the models or at least a large subset. The G-code would be entered on the remote controller as before and decoded into channel, date, time and length information, which would be stored in the remote controller. Via clock 85, the time would be checked and when the correct time arrives the remote controller would automatically send out commands to the VCR unit for tuning to the correct channel and for starting and stopping the recording. It is estimated that only two (2) bytes per key for about 15 keys need to be stored for the vocabulary for each video cassette recorder/player model. Thus, to cover 50 models would only require about 30*50=1500 bytes of memory in the remote controller. It would be necessary to position the remote controller properly with respect to the VCR unit so that the infrared signals sent by the remote controller are received by the unit.

Another preferred embodiment is to provide a universal remote controller 90 with an embedded G-code decoder. Universal remote controllers provide the capability to mimic a number of different remote controllers. This reduces the number of remote controllers that a user needs to have. This is accomplished by having a learn function key 94 function on the universal remote controller, as shown in FIG. 5. If the learn function key 94 is pushed in conjunction with another key, the unit will enter into the learn mode. Incoming infra-red (IR) pulses from the remote controller to be learned are detected by the infra-red photodiode 96, filtered and wave-shaped into recognizable bit patterns before being recorded by a microcontroller into a battery-backed static RAM as the particular IR pulse pattern for that particular key. This is done for all the individual keys.

An example of more complex learning is the following. If the learn function key 94 in conjunction with the program key 26 are pushed when the G-code switch is "ON", the unit will recognize that it is about to record the keying sequence of a predetermined specific example of timer preprogramming of the particular VCR involved. The user will then enter the keying sequence from which the universal remote controller 90 can then deduce and record the protocol of the timer preprogramming sequence. This is necessary because different VCRs may have different timer preprogramming command formats.

If keys are pushed without the learn function key 94 involved, the microcontroller should recognize it is now in the execute mode. If the key is one of the direct command keys, the microcontroller will read back from its static RAM the stored pulse sequence and send out command words through the output parallel I/O to pulse the output light emitting diode 28. If the key is the PROG key and the G-code switch is "OFF", then the microcontroller should recognize the following keys up to the next PROG key as a timer preprogramming CDTL command and send it out through the light emitting diode 28. If the G-code switch 22 is set to "ON" and the program key 26 is pushed, the microcontroller should recognize the following keys up to the next PROG key as a G-code command for timer preprogramming. It will decode the G-code into channel, date, start time and length (CDTL) and the microcontroller will then look up in its static RAM "dictionary" the associated infra-red pulse patterns and concatenate them together before sending them off through the output parallel I/O to pulse the light emitting diode 28 to send the whole message in one continuous stream to the VCR.

FIG. 4 illustrates a possible realization of the G-code decoder 92 that could be built into the universal remote controller with embedded G-code decoder 90. A microcontroller 60 can be used as before to decode the G-code, as well as for interfacing with the input/output functions including the photodiode 96. Alternately, the G-code decoding can be performed with other hardware implementations.

The universal remote controller can also be used in another manner to simplify the interfacing problem with existing video cassette recorder/players. In particular, if the universal remote controller performs not only the G-code decoding to CDTL, but also keeps track of time via clock 85 in FIG. 4, then it is possible for the universal remote controller to send just channel, start record and stop commands to the video cassette recorder/player, which as explained before, are usually basic one key commands, which means there is no complicated protocol or sentence structure involved. Thus, to communicate with a diverse set of video cassette recorder/player models it is only necessary for the universal remote controller to "learn" each key of the remote controller it is replacing. The G-code would be entered on the universal remote controller as before and decoded into channel, date, time and length information, which would be stored in the universal remote controller. Via clock 85, the time would be checked and when the correct time arrives the universal remote controller would automatically send out commands to the VCR unit for tuning to the correct channel and for starting and stopping the recording. It would be necessary to position the universal remote controller properly with respect to the VCR unit so that the signals sent by the universal remote are received by the VCR unit.

There are a number of ways that the G-code decoding can be performed. The most obvious way is to just have a large look up table. The G-code would be the index. Unfortunately, this would be very inefficient and result in a very expensive decoder due to the memory involved. The total storage involved is a function of the number of total combinations. If we allow for 128 channels, 31 days in a month, 48 on the hour and on the half hour start times in a twenty four hour day, and 16 length selections in half hour increments, then the total number of combinations is 128.times.31.times.48.times.16=3,047,424. This number of combinations can be represented by a 7 digit number. The address to the table would be the 7 digit number. In the worse case, this requires a lookup table that has about 4,000,000 rows by 15 to 16 digital columns, depending on the particular protocol. These digital columns would correspond to the CDTL information required for "on screen programming". Each digit could be represented by a 4 bit binary number. Thus, the total storage number of bits required for the lookup table would be about 4,000,000.times.16.times.4=256,000,000. The present state of the art has about 1 million bits per chip. Thus, G-code decoding using a straightforward table lookup would require a prohibitively expensive number of chips.

Fortunately, there are much more clever ways of performing the G-code decoding. FIG. 6 is a flow diagram of a preferred G-code decoding technique. To understand G-code decoding, it is easiest to first explain the G-code encoding technique, for which FIG. 7 is the flow chart. Then the G-code decoding technique, which is the reverse of the G-code encoding will be explained.

The encoding of the G-codes can be done on any computer and is done prior to preparation of any program guide that would include G-codes. For each program that will be printed in the guide, a channel, date, time and length (CDTL) code 144 is entered in step 142. Step 146 separately reads the priority for the channel, date, time and length in the priority vector storage 122, which can be stored in read only memory 64. The priority vector storage 122 contains four tables: a priority vector C table 124, a priority vector D table 126, a priority vector T table 128 and a priority vector L table 130.

The channel priority table is ordered so that the most frequently used channels have a low priority number. An example of the data that is in priority vector C table 124 follows.

______________________________________ channel 4 7 2 3 5 6 11 13 . . . priority 0 1 2 3 4 5 6 7 . . . ______________________________________

Generally the dates of a month all have an equal priority, so the low number days in a month and the low number priorities would correspond in the priority vector D table as in the following example.

______________________________________ date 1 2 3 4 5 6 7 8 9 10 . . . priority 0 1 2 3 4 5 6 7 8 9 . . ______________________________________ .

The priority of the start times would be arranged so that prime time would have a low priority number and programs in the dead of the night would have a high priority number. For example, the priority vector T table would contain:

______________________________________ time 6:30 pm 7:00 pm 8:00 pm 7:30 pm . . . priority 0 1 2 3 . . . ______________________________________

An example of the data that is in the priority vector L table 130 is the following:

______________________________________ length of program (hours) 0.5 1.0 2.0 1.5 3.0 . . . priority 0 1 2 3 4 . . . ______________________________________

Suppose the channel date time length (CDTL) 144 data is 5 10 19.00 1.5, which means channel 5, 10th day of the month, 7:00 PM, and 1.5 hours in length, then for the above example the C.sub.p,D.sub.p,T.sub.p,L.sub.p data 148, which are the result of looking up the priorities for channel, date, time and length in priority tables 124, 126, 128 and 130 0f FIG. 7, would be 4 9 1 3. Step 150 converts C.sub.p,D.sub.p,T.sub.p,L.sub.p data to binary numbers. The number of binary bits in each conversion is determined by the number of combinations involved. Seven bits for C.sub.p, which can be denoted as C.sub.7 C.sub.6 C.sub.5 C.sub.4 C.sub.3 C.sub.2 C.sub.1, would provide for 128 channels. Five bits for D.sub.p, which can be denoted as D.sub.5
D.sub.4 D.sub.3 D.sub.2 D.sub.1, would provide for 31 days in a month. Six bits for T.sub.p , which can be denoted as T.sub.6 T.sub.5 T.sub.4 T.sub.3 T.sub.2 T.sub.1, would provide for 48 start times on each half hour of a twenty four hour day. Four bits for length, which can be denoted as L.sub.4 L.sub.3 L.sub.2 L.sub.1, would provide for a program length of up to 8 hours in half hour steps. Together there are 7+5+6+4=22 bits of information, which correspond to 2**22=4,194,304 combinations.

The next step is to use bit hierarchy key 120, which can be stored in read only memory 64 to reorder the 22 bits. The bit hierarchy key 120 can be any ordering of the 22 bits. For example, the bit hierarchy key might be:

______________________________________ L.sub.8 C.sub.3 . . . T.sub.2 C.sub.2 T.sub.1 C.sub.1 L.sub.1 D.sub.5 D.sub.4 D.sub.3 D.sub.2 D.sub.1 22 21 . . . 10 9 8 7 6 5 4 3 2 1 ______________________________________

Ideally the bit hierarchy key is ordered so that programs most likely to be the subject of timer preprogramming would have a low value binary number, which would eliminate keystrokes for timer preprogramming the most popular programs. Since all the date information has equal priority, then the D.sub.5 D.sub.4 D.sub.3 D.sub.2 D.sub.1 bits are first. Next T.sub.1 C.sub.1 L.sub.1 are used, because for whatever date it is necessary to have a time channel and length and T.sub.1 C.sub.1 L.sub.1 are the most probable in each case due to the ordering of the priority vectors in priority vector storage 122. The next bit in the hierarchy key is determined by the differential probabilities of the various combinations. One must know the probabilities of all the channels, times and lengths for this calculation to be performed.

For example, the probability for channels may be:

______________________________________ channel 4 7 2 3 5 6 11 13 . . . priority 0 1 2 3 4 5 6 7 . . . probability (%) 5 4.3 4 3 2.9 2.1 2 1.8 . . . ______________________________________

The probabilities for times might be:

______________________________________ time 6:30 pm 7:00 pm 8:00 pm 7:30 pm . . . priority 0 1 2 3 . . . probability (%) 8 7.8 6 5 . . . ______________________________________

And, the probabilities for lengths might be:

______________________________________ length of program (hours) 0.5 1.0 2.0 1.5 3.0 . . . priority 0 1 2 3 4 . . . probability (%) 50 20 15 5 4 . . . ______________________________________

The probabilities associated with each channel, time and length, as illustrated above, are used to determine the proper ordering. Since the priority vector tables are already ordered by the most popular channel, time, and length, the order in which to select between the various binary bits for one table, for example selecting between the C.sub.7 C.sub.6 C.sub.5 C.sub.4 C.sub.3 C.sub.2 C.sub.1 bits, is already known. The C.sub.1 bit would be selected first because as the lowest order binary bit it would select between the first two entries in the channel priority table. Then the C.sub.2 bit would be selected and so on. Similarly, the T.sub.1 and L.sub.1 bits would be used before any of the other time and length bits. A combination of the C.sub.1, T.sub.1, L.sub.1 and D.sub.5 D.sub.4 D.sub.3 D.sub.2 D.sub.1 bits should be used first, so that all the information is available for a channel, date, time and length. The D.sub.5 D.sub.4 D.sub.3 D.sub.2 D.sub.1 bits are all used because the date bits all have equal priority and all are needed to specify a date even if some of the bits are binary zero.

At this point the bit hierarchy key could be:

The first channel binary bit C.sub.1 by itself can only select between 2.sup.1 =2 channels, and the first two channels have a probability percent of 5 and 4.3, respectively. So the differential probability of C.sub.1 is 9.3. Similarly, the differential probability of T.sub.1 is 8+7.8=15.8, and the differential probability of L.sub.1 is 50+20=70. If the rules for ordering the bit hierarchy key are strictly followed, then the first 8 bits of the bit hierarchy key should be ordered as:

because L.sub.1 has the highest differential priority so it should be next most significant bit after D.sub.5, followed by T.sub.1 as the next most significant bit, and then C.sub.1 as the next most significant bit. Notice that the bit hierarchy key starts with the least significant bit D.sub.1, and then is filled in with the highest differential probability bits. This is for the purpose of constructing the most compact codes for popular programs.

The question at this point in the encoding process is what should the next most significant bit in the hierarchy key be: T.sub.2, C.sub.2, or L.sub.2. This is again determined by the differential probabilities, which can be calculated from the above tables for each bit. Since we are dealing with binary bits, the C.sub.2 in combination with C.sub.1 selects between 2.sup.2 =4 channels or 2 more channels over C.sub.1 alone. The differential probability for C.sub.2 is then the additional probabilities of these two additional channels and for the example this is: 4+3=7. In a similar manner C.sub.3 in combination with C.sub.1 and C.sub.2 selects between 2.sup.3 =8 channels or 4=2.sup.(3-1) more channels over the combination of C.sub.1 and C.sub.2. So the differential probability of C.sub.3 is the additional probabilities of these four additional channels and for the example this is: 2.9+2.1+2+1.8=8.8. In a similar manner, the differential probabilities of T.sub.2 and L.sub.2 can be calculated to be 6+5=11 and 15+5=20, respectively. Once all the differential probabilities are calculated, the next step is determining which combinations of bits are more probable.

Now for the above example, which combination is more probable: T.sub.2 with C.sub.1 L.sub.1, or C.sub.2 with T.sub.1 L.sub.1, or L.sub.2 with T.sub.1 C.sub.1. This will determine the next bit in the key. So, which is greater:
11.times.9.3.times.70=7161; 7.times.15.8.times.70=7742; or 20.times.15.8.times.9.3=2938.8? In this case the combination with the greatest probability is 7.times.15.8.times.70=7742, which corresponds to C.sub.2 with T.sub.1 L.sub.1. So, C.sub.2 is selected as the next bit in the bit hierarchy key.

The next bit is selected in the same way. Which combination is more probable: C.sub.3 with T.sub.1 L.sub.1, or T.sub.2 with C.sub.1 or C.sub.2 and L.sub.1, or L.sub.2 with C.sub.1 or C.sub.2 and T.sub.1. For the example shown, which has the probability: 8.8.times.15.8.times.70=9732.8; 11.times.(9.3+7).times.70=12551; or 20.times.(9.3+7).times.15.8=5150.8? In this case the combination with the greatest probability is 11.times.(9.3+7).times.70=12551, which corresponds T.sub.2 with C.sub.1 or C.sub.2 and L.sub.1. So, T.sub.2 is selected as the next bit in the bit hierarchy key. This procedure is repeated for all the differential probabilities until the entire key is found.

Alternately, the bit hierarchy key can be just some arbitrary sequence of the bits. It is also possible to make the priority vectors interdependent, such as making the length priority vector dependent on different groups of channels. Another technique is to make the bit hierarchy key 120 and the priority vector tables 122, a function of clock 42, as shown in FIG. 7. This makes it very difficult for the key and therefore the coding technique to be duplicated or copied.

For example it is possible to scramble the date bits in the bit hierarchy key 120 as a function of the clock. Changing the order of the bits as a function of the clock would not change the effectiveness of the bit hierarchy key in reducing the number of binary bits for the most popular programs, because the date bits all are of equal priority. This could be as simple as switching the D.sub.1 and D.sub.5 bits periodically, such as every day or week. Thus the bit hierarchy key 120 would switch between

______________________________________ . . . C.sub.1 T.sub.1 L.sub.1 D.sub.5 D.sub.4 D.sub.3 D.sub.2 D.sub.1 and . . . C.sub.1 T.sub.1 L.sub.1 D.sub.1 D.sub.4 D.sub.3 D.sub.2 D.sub.5. ______________________________________

Clearly other permutations of the bit hierarchy key as a function of the clock are possible.

The priority vector tables could also be scrambled as a function of the clock. For example, the first two channels in the priority channel table could just be swapped periodically. If this technique is followed, then the C.sub.p of 148 in FIG.
7 would change as a function of the clock 42. For example,

______________________________________ channel 4 7 2 3 5 6 11 13 . . . priority 0 1 2 3 4 5 6 7 . . . ______________________________________

would change periodically to:

______________________________________ channel 7 4 2 3 5 6 11 13 . . . priority 0 1 2 3 4 5 6 7 . . . ______________________________________

This would be a fairly subtle security technique, because a decoder that was otherwise correct would only fail if those first two channels were being used. Other clock dependencies are also possible to provide security for the coding technique.

However it is derived, the bit hierarchy key 120 is determined and stored. In step 154 the binary bits of C.sub.p,D.sub.p,T.sub.pl,L.sub.p are rearranged according to the bit hierarchy key 120 to create one 22 bit binary number. Then the resulting 22 bit binary number is converted to decimal in the convert binary number to decimal G-code step 156. The result is G-code 158.

If the priority vector and the bit hierarchy key are well matched to the viewing habits of the general population, then it is expected that the more popular programs would require no more than 3 or 4 digits for the G-code.

Now that the encoding technique has been explained the decoding technique is just reversing the coding technique. This is done according to the flow chart of FIG. 6. This is the preferred G-code decoding that can be built into G-code decoder 38
in VCR 14 or the remote controller G-code decoders 82 and 92 in FIGS. 3 and 5.

The first step 102 is to enter G-code 104. Next the G-code 104 is converted to a 22 bit binary number in step 106. Then the bits are reordered in step 108 according to the bit hierarchy key 120 to obtain the reordered bits 110. Then the bits are grouped together and converted to decimal form in step 112. As this point we obtain C.sub.p,D.sub.p,T.sub.p,L.sub.p data 114, which are the indices to the priority vector tables. For the above example, we would have at this step the vector 4 9 1 3. This C.sub.p,D.sub.p,T.sub.p,L.sub.p data 114 is then used in step 116 to lookup channel, date, time, and length in priority vector storage 122. The CDTL 118 for the example above is 5 10 19.00 1.5, which means channel 5, 10th day of the month, 7:00 PM, and 1.5 hours in length.

If the coding technique is a function of the clock then it is also necessary to make the decoding technique a function of the clock. It is possible to make the bit hierarchy key 120 and the priority vector tables 122, a function of clock 42, as shown in FIG. 6. This again makes it very difficult for the key and therefore the coding technique to be duplicated or copied. It is also possible to have the decoding and encoding techniques dependent on any other predetermined or preprogrammable algorithm.

Although the above G-code encoding and decoding technique is a preferred embodiment, it should be understood that there are many ways to perform the intent of the invention which is to reduce the number of keystrokes required for timer preprogramming. To accomplish this goal there are many ways to perform the G-code encoding and decoding. There are also many ways to make the encoding and decoding technique more secure besides just making the encoding and decoding a function of the clock. This security can be the result of any predetermined or preprogrammed algorithm.

It is possible in the G-code coding and decoding techniques to use mixed radix number systems instead of binary numbers. For example, suppose that there are only 35 channels, which would require 6 binary bits to be represented; however, 6 binary bits can represent 64 channels, because 2.sup.6 =64. The result is that in a binary number system there are 29 unnecessary positions. This can have the effect of possibly making a particular G-code longer than it really needs to be. A mixed radix number system can avoid this result. For example, for the case of 35 channels, a mixed radix number system with the factors of 7.sup.1 and 5.sup.0 can represent 35 combinations without any empty space in the code. The allowed numbers for the 7.sup.1
factor are 0, 1, 2, 3, and 4. The allowed numbers for the 5.sup.0 factor are 0, 1, 2, 3, 4, 5, and 6. For example, digital 0 is represented in the mixed radix number system as 00. The digital number 34 is represented in the mixed radix number system as 46, because 4*7.sup.1 +6*5.sup.0=34. The major advantage of a mixed radix number system is in prioritizing the hierarchy key. If the first 5 channels have about equal priority and the next 30 are also about equal, then the mixed radix number system allows the two tiers to be accurately represented. This is not to say that a mixed radix number system is necessarily preferable. Binary numbers are easier to represent in a computer and use of a fixed radix number system such as binary numbers allows a pyramid of prioritization to be easily represented in the hierarchy key.

Another feature that is desirable in all of the embodiments is the capability to key in the G-code once for a program and then have the resulting CDTL information used daily or weekly. Ordinarily the CDTL information is discarded once it is used. In the case of daily or weekly recording of the same program, the CDTL information is stored and used until it is cancelled. The desire to repeat the program daily or weekly can be performed by having a "WEEKLY" or "DAILY" button on the remote controller or built into the VCR manual controls. Another way is to use one key, such as the PROG key and push it multiple times within a certain period of time such as twice to specify daily or thrice to specify weekly. For example, if the G-code switch is "ON" and the G-code for the desired program is 99 then daily recording of the program can be selected by the following keystrokes:

______________________________________ "PROG 99 DAILY PROG" or by: "PROG 99 PROG PROG". ______________________________________

The G-code 99 would be converted to CDTL information, which would be stored and used daily in this case. The recording would begin on the date specified and continue daily after that using the same channel time and length information. A slight twist is that daily recording could be automatically suspended during the weekends, because most daily programs are different on Saturday and Sunday.

Once a daily or weekly program is set up, then it can be used indefinitely. If it is desired to cancel a program and if there is a "CANCEL" button on the remote controller or manual control for the VCR, then one way to cancel a program (whether it is a normal CDTL, daily or weekly entry) is to key in the following:

where xx is the G-code. Again as before there are alternate ways of accomplishing this.

If "on screen programming" is available, then the programs that have been selected for timer preprogramming could be reviewed on the screen. The daily and weekly programs would have an indication of their type. Also the G-codes could be displayed along with the corresponding CDTL information. This would make it quite easy to review the current "menu" and either add more programs or cancel programs as desired.

A television calendar 200 according to this invention is illustrated in FIG. 8. As shown, the television calendar has multiple day of year sections 202, multiple day sections 204, multiple time of day sections 206, channel identifiers 208, and descriptive program identifiers 210, including the name of the program, arranged in a manner that is common in television guide publications. Arranged in relation to each channel identifier is a compressed code indication 212 or G-code containing the channel, date, time and length information for that entry in the television calendar. FIG. 8 shows how easy it is to perform timer programming. All one needs to do is find the program one wants to watch and enter the compressed code shown in the compressed code indication. This is in contrast to having to deal with all the channel, date, time and length entries separately. At least the channel, date and time are explicitly stated in the television guide. The length is usually only available by searching the guide to find the time of day section 204 where a new program begins and then performing some arithmetic to find the length of the program. Using the compressed G-code avoids all these complications.

For cable television programs, there is an additional issue that needs to be addressed for the compressed G-code to be useful. In a normal television guide, CDTL information is available for all the normal broadcast channels in the form of numbers including the channel numbers, such as channel 4 or 7. However, for cable channels like HBO, ESPN etc., only the names of the channels are provided in most television listings. The reason for this is that in some metropolitan areas, such as Los Angeles, there may be only one (1) edition of television guide, but there may be quite a few cable carriers, each of which may assign HBO or ESPN to different cable channel numbers. In order for a compressed code such as the G-code to be applicable to the cable channels as published by a wide area television guide publication, the following approach can be used.

First, all the cable channels would be permanently assigned a unique number, which would be valid across the nation. For example, we could assign ESPN to cable channel 1, HBO as cable channel 2, SHO as cable channel 3, etc. This assignment would be published by the television guide publications.

The video cassette recorder apparatus, such as the remote controller, the VCR unit or both, could then be provided with two (2) extra modes: "set" and "cable channel". One way of providing the user interface to these modes would be to provide two (2) extra buttons: one called SET and one called CABLE CHANNEL. The buttons could be located on the video cassette recorder unit itself or located on a remote controller, as shown in FIGS. 1, 3 and 5, where SET is element 168 and CABLE CHANNEL is element 170. Of course, other user interfaces are possible.

Next, the television viewer would have to go through a one-time "setting" procedure of his VCR for all the cable channels that he would likely watch. This "setting" procedure would relate each of the assigned numbers for each cable channel to the channel number of the local cable carrier. For example, suppose that the local cable carrier uses channel 6 for ESPN, then cable channel number 1 could be assigned to ESPN, as shown in the following table.

______________________________________ Cable Channel Assigned Channel Number in Name Cable Chan. No. the local cable carrier ______________________________________ EPSN 1 6 HBO 2 24 SHO 3 3 . . . . . . . . . DIS 8 25 ______________________________________

The user could perform the "setting" procedure by pushing the buttons on his remote controller as follows:

______________________________________ SET 06 CABLE CHANNEL 1 PROGRAM SET 24 CABLE CHANNEL 2 PROGRAM SET 23 CABLE CHANNEL 3 PROGRAM SET 25 CABLE CHANNEL 8 PROGRAM ______________________________________

The "setting" procedure would create a cable channel address table 162, which would be loaded into RAM 52 of command controller 36. For the above example, the cable channel address table 162 would have the following information.

______________________________________ CABLE CHANNEL ADDRESS TABLE 162 ______________________________________ 1 6 2 24 3 23 . . . . . . 8 25 ______________________________________

After the "setting" procedure is performed, the TV viewer can now select cable channels for viewing by the old way: eg. pushing the key pad buttons 24 will select HBO. He can also do it the new way: eg. by pushing CABLE CHANNEL 2, which will also select HBO. The advantage of the new way is that the television guide will publish [C2] next to the program description, so the viewer will just look up the assigned channel number identifier instead of having to remember that HBO is local cable channel 24. When the CABLE CHANNEL button is pushed, command controller 36 knows that it will look up the local cable channel number in cable channel address table 162 to tune the VCR to the correct channel.

For timer preprogramming and for using the compressed G-code, a way to differentiate between broadcast and cable channels is to add an eighth channel bit, which would be set to 0 for normal broadcast channels and 1 for cable channels such as HBO. This eighth channel bit could be one of the low order bits such as the third bit C.sub.3 out of the eight channel bits, so that the number of bits to specify popular channels is minimized, whether they be normal broadcast or cable channels. For a normal broadcast channel, the 7 other bits can be decoded according to priority vector C table 124. For a cable channel, the 7 other bits can be decoded according to a separate cable channel priority vector table 160, which could be stored in ROM 54 of microcontroller 36. The cable channel priority vector table can be set ahead of time for the entire country or at least for an area covered by a particular wide area television guide publication.

A television guide that carries the compressed code known as the G-code will now print the cable channel information as follows:

______________________________________ 6:30 pm [C2] HBO xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (4679) xxxxxx(program description)xxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx ______________________________________

The [C2] in front of HBO reminds the viewer that he needs only to push CABLE CHANNEL 2 to select HBO. The (4679) is the G-code indication for this particular program.

FIG. 8 shows a section of a television guide. The cable channels all have an assigned cable channel number 188 after the cable channel mnemonic. Other than that the cable channel information is arranged the same as the broadcast channels with a compressed G-code 212 associated with the channel.

For timer preprogramming, the viewer need only enter the number 4679 according to the unit's G-code entry procedure, eg. PROG 4679 PROG. The G-code decoder unit will decode this G-code into "cable channel 2" and will also signal the command controller 36 with a cable channel signal 164, as shown in FIGS. 1 and 2, because the extra channel bit will be "1" which distinquishes that the G-code is for a cable channel; then, since the association of "cable channel 2" with channel 24 has been established earlier in the "setting" procedure, the command controller, if it has received a cable channel signal, will immediately look up 2 in the cable channel address table 162 to translate it to cable channel 24, which will be used as the recording channel at the appropriate time. By associating the G-code with the assigned cable channel number rather than the local cable channel number, the G-code for that program will be valid in the whole local area, which may have many different cable carriers each of which may have different local cable channel numbers.

To include the cable channel compressed G-code feature, the decoding and encoding algorithms are as shown in FIGS. 9 and 10, respectively. The encoding should be explained first before the decoding. The primary change in FIG. 10 from FIG. 7 is that a cable channel priority vector table 160 has been added and is used in look up priority step 180 if a cable channel is being encoded. Also if a cable channel is being encoded then the cable channel bit is added in the correct bit position in the convert C.sub.p D.sub.p T.sub.p L.sub.p to binary numbers step 182. This could be bit C.sub.3, as discussed before. The bit hierarchy key could be determined as before to compress the number of bits in the most popular programs; however, it needs to be
23 bits long to accommodate the cable channel bit. The maximum compressed G-code length could still be 7 digits, because 2.sup.23 =8,388,608.

The decoding is shown in FIG. 9 and is just the reverse of the encoding process. After step 108, test cable channel bit 174 is added and effectively tests the cable channel bit to determine if it is a "1". If so then the command controller 36
is signaled via cable channel signal 164 of FIGS. 1 and 2 that the CDTL 118 that will be sent to it from G-code decoder 38 is for a cable channel. Then the command controller knows to look up the local cable carrier channel number based on the assigned cable channel number. In step 176 of FIG. 9, the priority vector tables including the cable channel priority vector table 160 are used to look up the CDTL 118 information.

An alternate to having the command controller receive a cable channel signal 164 is for the G-code decoder to perform all of the decoding including the conversion from assigned cable channel number to local cable carrier number. This would be the case for the remote controller implementation of FIG. 3. FIG. 11 shows the implementation of the entire decode algorithm if this step is included. All that needs to be added is convert assigned channel to local cable carrier channel step 166, which performs a lookup in cable channel address table 162, if the cable channel bit indicates that a cable channel is involved. Step 166 effectively replaces step 174 in FIG. 9.

Another issue that needs addressing is the number of programs that can be preprogrammed. Since the G-code greatly simplifies the process of entering programs, it is likely that the user will quickly learn and want to enter a large number of programs; however, some existing VCRs can only store up to four (4) programs, while some can store as many as eight. Thus, the user may get easily frustrated by the programming limitations of the VCR.

One approach to this problem, is to perform the compressed G-code decoding in the remote controller and provide enough memory there to store a large number of programs, eg. 20 or 40. The remote controller would have the capability of transferring periodically several of these stored programs at a time to the VCR main unit. To provide this capability, extra memory called stack memory 76 is required inside the remote unit, as shown in FIG. 12, which other than that is identical to FIG. 4. Stack memory 76 can be implemented with a random access memory, which may in fact reside in the microcontroller itself, such as RAM 62.

The stack memory 76 is where new entry, insertion & deletion of timer preprogramming information is carried out. It is also where editing takes place. The top memory locations of the stack, for example the first 4 locations, correspond exactly to the available timer preprogramming memory in the VCR main unit. Whenever the top of the stack memory is changed, the new information will be sent over to the VCR main unit to update it.

FIG. 13 shows the sequence of events when the user enters a G-code program on the keypad of the remote controller. For illustration purposes, suppose the VCR main unit can only handle four (4) programs. Suppose also that the stack memory capacity is 20 timer preprograms. Referring to the flow chart in FIG. 13, when the user enters a G-code in step 230, the microcontroller 60 first decodes it into the CDTL information in step 234 and displays it on the display unit with the additional word "entered" also displayed. The microcontroller then enters the decoded program into the stack memory in step 236.

If this is the first program entered, it is placed at the top location of the stack memory. If there are already programs in the stack memory, the newly entered program will first be provisionally placed at the bottom of the stack memory. The stack memory will then be sorted into the correct temporal order in step 240, so that the earliest program in time will appear in the top location and the last program in time will be at the bottom. Notice that the nature of the temporally sorted stack memory is such that if stack memory location n is altered, then all the locations below it will be altered.

For example, suppose the stack memory has six (6) entries already temporally ordered, and a new entry is entered whose temporal ordering places it in location 3 (1 being the top location). If this entry is placed into location 3, information which was in location 3, 4, 5, 6 will be shifted to locations 4, 5, 6, and 7. Locations 1 and 2 will remain unchanged.

The microcontroller 60, after doing the temporal ordering, checks in step 242 whether the first n entries have changed from before, where for the current example n equals 4. In this case, since a new program has been entered into location 3, what used to be in location 3 now moves to location 4. Since the VCR's main unit program menu of 4 entries should correspond exactly to location 1 through 4 of the stack memory, entries 3 and 4 on the VCR main unit must now be revised. The microcontroller therefore sends out the new entries 3 & 4 to the main unit, in step 244 of FIG. 13. If the newly entered program, after temporal ordering, gets entered into location 5, then entries 1 through 4 have not changed from before and the microcontroller will not send any message to the VCR main unit and the microcontroller will just resume monitoring the clock 85 and the keyboard 88 as per step 246. It is assumed that when the user enters the G-code in step 230, the remote controller is pointed at the VCR main unit. The other steps of FIG. 13 happen so fast that the changes are sent in step 244 while the remote controller is still being pointed at the VCR main unit.

If the user decides to delete a program in step 232, the deletion is first carried out in the stack memory. If the first 4 entries are affected, the microcontroller will send the revised information over to the VCR main unit. If the first 4
entries are not affected, then again the remote controller unit will not send anything. The deletion will only change the lower part of the stack (lower meaning location 5 to 20). This new information will be sent over to the VCR main unit at the appropriate time.

In the meantime, the VCR main unit will be carrying out its timer programming function, completing its timing preprogramming entries one by one. By the time all 4 recording entries have been completed, the stack in the remote must send some new entries over to "replenish" the VCR main unit (if the stack has more than 4 entries).

The real time clock 85 in the remote controller unit is monitored by the microcontroller to determine when the programs in the main unit have been used