Apparatus for selective routing of information signals

• US 5,592,321 A
• Filed: 04/13/1995
• Issued: 01/07/1997
• Est. Priority Date: 04/13/1995
• Status: Expired due to Term

• Current Assignee: Elbex Video Limited (Elbex Japan Ltd.)
• Original Assignee: Elbex Video Limited (Elbex Japan Ltd.)
• Inventors: Elberbaum, David
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/421,615
• Time in Patent Office: 635 Days
• Field of Search: 359/109, 359/117, 359/154, 359/159, 359/163, 359/173, 345/1-2, 348/15, 348/385, 348/388, 348/705-706, 348/722, 348/359, 348/218, 348/335
• US Class Current: 398/45
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04N 5/268 Signal distribution or switching
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0045 Synchronisation

Abstract

An apparatus for the selective routing of information signals includes a plurality of transmitting units. Each transmitting unit has a transmitter for transmitting information by converting the same into a light signal. A plurality of fiber optic lines are provided for carrying the light signal from the transmitting units. Each fiber optic line corresponds to one of the transmitting units. At least one receiving unit is provided for selectively receiving the information carried by the fiber optic lines. The receiving unit includes a liquid crystal panel having a plurality of light passing areas. The optical transmission properties of the light passing areas are controlled individually, for selectively receiving the light from the fiber optic lines, for effecting connections between the transmission units and the receiving unit by the fiber optic lines in any arbitrary combination. Each light passing area corresponds to one of the fiber optic lines. A receiver which is part of the receiving unit generates an electrical signal converted from the light which passes through the liquid crystal panel.

Claims

1. An apparatus for the selective routing of information signals, comprising:

a plurality of transmitting means, each having a transmitter for transmitting an information signal by converting said information signal into a light signal;

a plurality of fiber optic lines for carrying said light signal from said transmitting means, each fiber optic line respectively corresponding to one of said transmitting means; and

at least one receiving means for selectively receiving said light signal carried by said fiber optic lines;

wherein said receiving means includes a liquid crystal panel having a plurality of light passing areas the optical transmission properties of said plurality of light passing areas being individually controlled, receiving light from said fiber optic lines, each light passing area respectively corresponding to one of said fiber optic lines, a receiver for generating an electrical signal from the light passing through said liquid crystal panel, add a selection means for individually controlling said light passing areas for selecting any of said light passing areas to be switched on so as to selectively connect, by said fiber optic lines, said transmitting means and said receiving means in any arbitrary combination with each other.

2. An apparatus according to claim 1, wherein each transmitter includes a photoemissive element for generating said light signal, and a driver for driving the photoemissive element by said information signal, and wherein said receiver includes a light receiving element for receiving said light signal passing through said liquid crystal panel, and a converter for converting said light signal received by said light receiving element into electrical output signal.

3. An apparatus according to claim 2, wherein each transmitting means further includes a lens for directing said light signal generated by said photoemissive element toward said fiber optic lines, and wherein said receiving means further includes a lens for directing said light signal passing through said liquid crystal panel toward said receiver.

4. An apparatus according to claim 1, further comprising:

a plurality of video signal generating means respectively connected to said plurality of transmitting means through a transmission line for feeding a video signal as said information signal to the transmitter of the corresponding transmitting means; and

video signal processing means for reproducing and/or recording an image corresponding to the video signal contained in an electrical output signal output from said receiver.

5. An apparatus according to claim 2, further comprising:

a plurality of video signal generating means respectively connected to said plurality of transmitting means through a transmission line for feeding a video signal as said information signal to the transmitter of the corresponding transmitting means; and

video signal processing means for reproducing and/or recording an image corresponding to the video signal contained in said electrical output signal fed from said receiver.

6. An apparatus according to claim 3, further comprising:

a plurality of video signal generating means respectively connected to said plurality of transmitting means through a transmission line for feeding a video signal as said information signal to the transmitter of the corresponding transmitting means; and

video signal processing means for reproducing and/or recording an image corresponding to the video signal contained in said electrical output signal fed from said receiver.

7. An apparatus according to claim 4, further comprising:

an external synchronizing signal generating means for generating and feeding external synchronizing signal to said video signal generating means;

wherein each video signal generating means includes a synchronizing signal generation circuit for generating composite video signals synchronized with said external synchronizing signal.

8. An apparatus according to claim 5, further comprising:

an external synchronizing signal generating means for generating and feeding an external synchronizing signal to said video signal generating means;

wherein each video signal generating means includes a synchronizing signal generation circuit for generating composite video signals synchronized with said external synchronizing signal.

9. An apparatus according to claim 6, further comprising:

an external synchronizing signal generating means for generating and feeding an external synchronizing signal to said video signal generating means;

wherein each video signal generating means includes a synchronizing signal generation circuit for generating composite video signals synchronized with said external synchronizing signal.

10. An apparatus according to claim 7, wherein said external synchronizing signal is a pulse signal having a voltage level higher than the maximum voltage level or lower than the minimum voltage level of said video signal, generated during the vertical blanking period of said video signal, wherein each transmitting means includes a circuit for injecting said external synchronizing signal into a transmission line extending from said video signal generating means to said transmitter or through a separate transmission line, and wherein said video signal generating means further includes a comparing circuit for extracting said external synchronizing signal by comparing the signal level of said pulse signal with a reference signal having a predetermined voltage level and for applying the extracted external synchronizing signal to said synchronizing signal generation circuit.

11. An apparatus according to claim 8, wherein said external synchronizing signal is a pulse signal having a voltage level higher than the maximum voltage level or lower than the minimum voltage level of said video signal, generated during the vertical blanking period of said video signal, wherein each transmitting means includes a circuit for injecting said external synchronizing signal into a transmission line extending from said video signal generating means to said transmitter or through a separate transmission line, and wherein said video signal generating means further includes a comparing circuit for extracting said external synchronizing signal by comparing the signal level of said pulse signal with a reference signal having a predetermined voltage level and for applying the extracted external synchronizing signal to said synchronizing signal generation circuit.

12. An apparatus according to claim 9, wherein said external synchronizing signal is a pulse signal having a voltage level higher than the maximum voltage level or lower than the minimum voltage level of said video signal, generated during the vertical blanking period of said video signal, wherein each transmitting means includes a circuit for injecting said external synchronizing signal into a transmission line extending from said video signal generating means to said transmitter or through a separate transmission line, and wherein said video signal generating means further includes a comparing circuit for extracting said external synchronizing signal by comparing the signal level of said pulse signal with a reference signal having a predetermined voltage level and for applying the extracted external synchronizing signal to said synchronizing signal generation circuit.

13. An apparatus according to claim 10, wherein each transmitting means further includes a circuit for removing said external synchronizing signal from the information signal converted into light signal.

14. An apparatus according to claim 11, wherein each transmitting means further includes a circuit for removing said external synchronizing signal from the signal fed to said driver.

15. An apparatus according to claim 12, wherein each transmitting means further includes a circuit for removing said external synchronizing signal from the signal fed to said driver.

16. An apparatus according to claim 4, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical signal for feeding the extracted identification code signal to said video signal processing means.

17. An apparatus according to claim 5, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

18. An apparatus according to claim 6, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

19. An apparatus according to claim 7, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

20. An apparatus according to claim 8, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

21. An apparatus according to claim 9, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

22. An apparatus according to claim 10, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

23. An apparatus according to claim 11, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

24. An apparatus according to claim 12, wherein each video signal generation means includes an identification code signal generation circuit for generating an identification code signal corresponding to an identification code respectively allotted to said video signal generating means for injecting said identification code signal into said video signal, and wherein said receiving means further includes an identification code signal processing means for extracting said identification code signal from said electrical output signal for feeding the extracted identification code signal to said video signal processing means.

25. An apparatus according to claim 16 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

26. An apparatus according to claim 17 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

27. An apparatus according to claim 18 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

28. An apparatus according to claim 19 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

29. An apparatus according to claim 20 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

30. An apparatus according to claim 21 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

31. An apparatus according to claim 22 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

32. An apparatus according to claim 23 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said Identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

33. An apparatus according to claim 24 wherein each identification code signal processing means includes a memory for storing an identification data for each allotted identification code, a decoding circuit for decoding the extracted said identification code signal to generate a decoder signal, and a controller for retrieving said identification data pertaining said decoder signal from said memory for superimposing said identification data onto said video signal.

34. An apparatus according to claim 25, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

35. An apparatus according to claim 26, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

36. An apparatus according to claim 27, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

37. An apparatus according to claim 28, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

38. An apparatus according to claim 29, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

39. An apparatus according to claim 30, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

40. An apparatus according to claim 31, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

41. An apparatus according to claim 32, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

42. An apparatus according to claim 33, further comprising:

control means for generating a control signal combining a coded control command for controlling said video signal generating means together with annexed identification code signal corresponding to the identification code respectively allotted to each video signal generating means;

wherein said control signal is applied to said video signal generating means to operate a circuit corresponding to said control signal, only when the identification code signal annexed to said control signal corresponds to the identification code signal allotted to said video signal generating means.

43. An apparatus according to claim 34, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

44. An apparatus according to claim 35, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

45. An apparatus according to claim 36, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

46. An apparatus according to claim 37, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

47. An apparatus according to claim 38, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

48. An apparatus according to claim 39, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

49. An apparatus according to claim 40, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

50. An apparatus according to claim 41, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

51. An apparatus according to claim 42, wherein said control signal is injected into said transmission line extended from said transmitting means to said video signal generating means, and wherein said video signal generating means further includes a control signal processing means for extracting said control signal from said transmission line for feeding the extracted control signal to a circuit corresponding to said extracted control signal, when the identification code signal annexed to said control signal corresponds to the identification code allotted to said video signal generating means.

52. An apparatus according to claim 34, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

53. An apparatus according to claim 35, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

54. An apparatus according to claim 36, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

55. An apparatus according to claim 37, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

56. An apparatus according to claim 38, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

57. An apparatus according to claim 39, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

58. An apparatus according to claim 40, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

59. An apparatus according to claim 41, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

60. An apparatus according to claim 42, wherein each receiving means further includes a photo emissive element for converting said control signal together with said annexed identification code signal generated by said control means into a control light signal for feeding said control light signal to said transmitting means through said fiber optic lines, and wherein each transmitting means further includes a light receiving element for converting said control light signal carried through said fiber optic lines into an electrical control signal, for injecting said electrical controls signal into said transmission line.

61. An apparatus according to claim 52, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

62. An apparatus according to claim 61, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

63. An apparatus according to claim 53, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

64. An apparatus according to claim 63, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

65. An apparatus according to claim 54, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

66. An apparatus according to claim 65, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

67. An apparatus according to claim 55, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

68. An apparatus according to claim 67, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

69. An apparatus according to claim 56, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

70. An apparatus according to claim 69, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

71. An apparatus according to claim 57, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

72. An apparatus according to claim 71, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

73. An apparatus according to claim 58, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

74. An apparatus according to claim 73, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

75. An apparatus according to claim 59, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

76. An apparatus according to claim 75, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

77. An apparatus according to claim 60, wherein each receiving means further includes an individual control circuit for feeding said control signal to said fiber optic lines for carrying said control signal to said transmitting means.

78. An apparatus according to claim 77, wherein each transmitting means feeds said control signal to a transmission line commonly used for the video signal and the control signal, said transmission line being a line extended from said transmitting means to said video signal generating means or to a separate control transmission line.

79. An apparatus according to claim 61, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

80. An apparatus according to claim 63, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

81. An apparatus according to claim 65, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

82. An apparatus according to claim 67, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

83. An apparatus according to claim 69, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

84. An apparatus according to claim 71, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

85. An apparatus according to claim 73, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

86. An apparatus according to claim 75, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

87. An apparatus according to claim 77, further comprising:

a master control unit for supervising the state controlled by said control circuit in order to prevent any conflicting control commands or prohibited commands.

88. An apparatus according to claim 7, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

89. An apparatus according to claim 8, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

90. An apparatus according to claim 9, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

91. An apparatus according to claim 10, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

92. An apparatus according to claim 11, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

93. An apparatus according to claim 9, wherein said selection means is respectively arranged for each receiving means for individually controlling said light passing areas of said liquid crystal panel, and wherein said selection means is synchronized by said external synchronizing signal to time the selection of any of said plurality of light passing areas during the vertical blanking period.

94. An apparatus according to claim 88 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

95. An apparatus according to claim 89 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

96. An apparatus according to claim 90 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

97. An apparatus according to claim 91 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

98. An apparatus according to claim 92 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

99. An apparatus according to claim 93 further comprising:

a master selection circuit for supervising the state of selection by said selection means.

100. Apparatus as claimed in claim 16, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

101. Apparatus as claimed in claim 17, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

102. Apparatus as claimed in claim 18, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

103. Apparatus as claimed in claim 19, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

104. Apparatus as claimed in claim 20, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

105. Apparatus as claimed in claim 21, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

106. Apparatus as claimed in claim 22, wherein said identification code signal generation circuit is included in said transmitting means instead of being Included In said video signal generating means.

107. Apparatus as claimed in claim 23, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

108. Apparatus as claimed in claim 24, wherein said identification code signal generation circuit is included in said transmitting means instead of being included in said video signal generating means.

109. An apparatus according to claim 4, wherein each video signal generating means further includes a signal mixing means for generating a mixed signal composed of a video signal and an audio signal by injecting the audio signal into said video signal, and for feeding said mixed signal to said transmission line.

110. An apparatus according to claim 109, wherein each receiving means further includes an audio signal retrieving means for outputting the audio signal by retrieving said audio signal from said electrical output signal.

111. An apparatus according to claim 5, wherein each transmitting means further includes a signal mixing means for generating a mixed signal composed of a video signal and an audio signal by injecting the audio signal into said video signal and for feeding said mixed signal to said driver.

112. An apparatus according to claim 5, wherein each video signal generating means further includes a signal mixing means for generating a mixed signal composed of a video signal and an audio signal by injecting the audio signal into said video signal, and for feeding said mixed signal to said transmission line.

113. An apparatus according to claim 111, wherein each receiving means further includes an audio signal retrieving means for outputting the audio signal by retrieving said audio signal from said electrical output signal.

114. An apparatus according to claim 112, wherein each receiving means further includes an audio signal retrieving means for outputting the audio signal by retrieving said audio signal from said electrical output signal.

115. An apparatus according to claim 6, wherein each transmitting means further includes a signal mixing means for generating a mixed signal composed of a video signal and an audio signal by injecting the audio signal into said video signal and for feeding said mixed signal to said driver.

116. An apparatus according to claim 6, wherein each video signal generating means further includes a signal mixing means for generating a mixed signal composed of a video signal and an audio signal by injecting the audio signal into said video signal, and for feeding said mixed signal to said transmission line.

117. An apparatus according to claim 115, wherein each receiving means further includes an audio signal retrieving means for outputting the audio signal by retrieving said audio signal from said electrical output signal.

118. An apparatus according to claim 116, wherein each receiving means further includes an audio signal retrieving means for outputting the audio signal by retrieving said audio signal from said electrical output signal.