Apparatus for transmitting lightwave

• US 5,570,220 A
• Filed: 09/20/1994
• Issued: 10/29/1996
• Est. Priority Date: 09/20/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Mori, Koji, Kobayashi, Jun, Okada, Kenji, Sano, Kenji, Matsumoto, Kenji, Itoh, Shigeyuki
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US08/309,412
• Time in Patent Office: 770 Days
• Field of Search: 348/372, 348/375, 348/374, 348/376, 348/6, 348/723, 348/725, 348/343, 348/344, 348/359, 348/734, 348/335, 348/12, 348/16, 358/906, 358/909.1, 358/335, 359/161, 359/172, 359/118, 359/146, 359/142
• US Class Current: 398/113
• CPC Class Codes: H04B 10/114 Indoor or close-range type systems
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission
• CPC Class Codes: Y10S 358/906 Hand-held camera with recorder in a single unit

Abstract

Apparatus for achieving contact-less linking between a transmitting unit and a receiving unit when transmitting video signal, audio signal, control signal, or digital data therebetween. The apparatus includes a switch circuit which switches the output signal of a light emitting integrated circuit to a first set of light guides for spatial transmission of an optical signal representing the video, audio and control signals and digital data and to a second set of light guides for near-by transmission of the optical signal.

Claims

1. An interface apparatus for interfacing a signal producing apparatus to display apparatus having a display screen and an audio output device by use of optical signals, said signal producing apparatus produces video, audio, control and digital data signals, said interface apparatus comprising:

a first converter for converting at least two of said signals produced by said signal producing apparatus into an optical signal;

a first set of light guides for guiding said optical signal for transmission from a transmitting unit to a receiving unit, said first set of light guides includes a spatial transmission light guide and a near-by transmission light guide;

a second set of light guides for receiving said optical signal from said transmitting unit and guiding said optical signal into said receiving unit, said second set of light guides includes a spatial receiving light guide and a near-by receiving light guide;

a switch for applying said optical signal to said spatial transmission light guide for transmission of said optical signal from said spatial transmission light guide to said spatial receiving light guide when spatial transmission between said transmitting unit and said receiving unit is to be conducted and applying said optical signal to said near-by transmission light guide for transmission of said optical signal from said near-by transmission light guide to said near-by receiving light guide when near-by transmission between said transmitting unit and said receiving unit is to be conducted; and

a second converter for converting said optical signal received by said receiving unit from the spatial or near-by receiving light guides into said at least two signals for use by said display apparatus.

2. An interface apparatus according to claim 1, wherein said first and second sets of light guides attenate said optical signal at different levels from each other.

3. An interface apparatus according to claim 1, wherein said first set of light guides emits said optical signal from a side portion of said transmitting unit.

4. An interface apparatus according to claim 1, wherein said transmitting unit includes said first converter and said first set of light guides.

5. An interface apparatus according to claim 4, wherein said transmitting unit is detachably connectable to said signal producing apparatus.

6. An interface apparatus according to claim 1, further comprising:

a first filter for filtering said optical signal from said first set of light guides prior to transmission of said optical signal to said receiving unit; and

a second filter for filtering said optical signal transmitted from said first set of light guides prior to receiving said optical signal in said second set of light guides.

7. An apparatus for transmitting an optical signal representing at least two of video, audio, control and digital data signals from a transmitting unit to a receiving unit comprising:

a modulator for modulating each of said at least two signals;

an electrical-optical converter for converting said at least two signals modulated by said modulator into an optical signal;

a first set of light guides for guiding said optical signal obtained by conversion in said electrical-optical converter for emission from said transmission unit to said receiving unit, said first set of light guides includes a spatial transmission light guide and a near-by transmission light guide;

a second set of light guides for receiving said optical signal from said transmitting unit and guiding said optical signal into said receiving unit, said second set of light guides includes a spatial receiving light guide and a near-by receiving light guide;

a switch for applying said optical signal to said spatial transmission light guide for transmission of said optical signal from said spatial transmission light guide to said spatial receiving light guide when spatial transmission between said transmitting unit and receiving unit is to be conducted and applying said optical signal to said near-by transmission light guide for transmission of said optical signal from said near-by transmission light guide to said near-by receiving light guide when near-by transmission between said transmitting unit and said receiving unit is to be conducted;

an optical-electrical converter for converting an optical signal received by the receiving unit from the spatial or near-by receiving light guides into an electrical signal; and

a demodulator for demodulating said electrical signal obtained by conversion in said optical-electrical converter thereby obtaining said at least two signals.

8. An apparatus according to claim 7, wherein said first and second sets of light guides attenuate said optical signal at different levels from each other.

9. An apparatus according to claim 7, wherein said first set of light guide emits said optical signal from a side portion of said transmitting unit.

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

a first filter for filtering said optical signal from said first set of light guides prior to transmission of said optical signal to said receiving unit; and

a second filter for filtering said optical signal transmitted from said first set of light guides prior to receiving said optical signal in said second set of light guides.

11. An apparatus for transmitting an optical signal representing at least two of video, audio, control, and digital data signals from a transmitting unit to a receiving unit, comprising:

a modulator for modulating each of said at least two signals;

a multiplexer for frequency-multiplexing said at least two signals modulated by said modulator;

an electrical-optical converter for converting the signal obtained by multiplexing in said multiplexer into an optical signal;

a first set of light guides for guiding said optical signal obtained by converting in said first electrical-optical converter for emission from said transmitting unit to said receiving unit, said first set of light guides includes a spatial transmission light guide and a near-by transmission light guide;

a second set of light guides for receiving said optical signal emitted from said transmitting unit and guiding said optical signal into said receiving unit, said second set of light guides includes a spatial receiving light guide and a near-by receiving light guide;

a switch for applying said optical signal to said spatial transmission light guide for transmission of said optical signal from said spatial transmission light guide to said spatial receiving light guide when spatial transmission between said transmitting unit and said receiving unit is to be conducted and applying said optical signal to said near-by transmission light guide for transmission of said optical signal from said near-by transmission light guide to said near-by receiving light guide when near-by transmission between said transmitting unit and said receiving unit is to be conducted;

an optical-electrical converter for converting said optical signal received by said receiving unit from said spatial or near-by receiving light guides into an electric signal; and

a demodulator for demodulating said electric signal obtained by conversion in said optical-electrical converter thereby obtaining said at least two signals.

12. An apparatus according to claim 11, wherein said first and second set of light guides attenuate said optical signal at different levels from each other.

13. An apparatus according to claim 11, wherein said first set of light guides emits said optical signal from a side portion of said transmitting unit.

14. An apparatus according to claim 11 wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said optical signal received by said receiving unit from said spatial or near-by receiving light guides into a plurality of electric signals; and

a selection circuit for selecting one of said electric signals having a maximum signal amplitude and supplying said selected electric signal to said demodulator.

15. An apparatus according to claim 14, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

16. An apparatus according to claim 14, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

17. An apparatus according to claim 14, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

18. An apparatus according to claim 14, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

19. An apparatus according to claim 11 wherein said electrical-optical converter comprises:

at least two electrical-optical conversion units each converting one of said at least two signals modulated by said modulator into an optical signal;

wherein said first set of light guides guides at least two of said optical signals obtained by conversion in said at least two electrical-optical conversion units for emission from said transmitting unit.

20. An apparatus according to claim 19, wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said at least two optical signals received by said receiving unit from said spatial or near-by receiving light guides into a plurality of electric signals; and

a selection circuit for selecting one of said electric signals having a maximum signal amplitude and supplying said selected electric signal to said demodulator.

21. An apparatus according to claim 20, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

22. An apparatus according to claim 20, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

23. An apparatus according to claim 20, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

24. An apparatus according to claim 20, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

25. An apparatus according to claim 11, further comprising:

a first filter for filtering said optical signal from said first set of light guides prior to transmission of said optical signal to said receiving unit; and

a second filter for filtering said optical signal transmitted from said first set of light guides prior to receiving said optical signal in said second set of light guides.

26. An apparatus for transmitting an optical signal representing at least two of video, audio, control and digital data signals from a transmitting unit to a receiving unit, comprising:

a modulator for modulating each of said at least two signals;

a multiplexer for frequency-multiplexing said at least two signals modulated by said modulator;

an electrical-optical converter for converting the signal obtained by multiplexing in said multiplexer into an optical signal;

a first light guide, positionable near said receiving unit for guiding said optical signal from said unit, transmitting unit for emission to said receiving unit so as to conduct near-by transmission of said optical signal from said transmitting unit to said receiving unit;

a second light guide for receiving said optical signal emitted from said transmitting unit and guiding said optical signal into said receiving unit;

an optical-electrical converter for converting said optical signal received and guided by said light guide into an electric signal; and

a demodulator for demodulating said electric signal obtained by conversion in said optical-electrical converter thereby obtaining said at least two signals.

27. An apparatus according to claim 26, wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said optical signal received and guided by said second light guide into respective electric signals; and

a selection unit for selecting one of said electric signals having a maximum signal amplitude and supplying said selected electric signal to said demodulator.

28. An apparatus according to claim 27, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

29. An apparatus according to claim 27, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

30. An apparatus according to claim 27, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

31. An apparatus according to claim 27, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

32. An apparatus according to claim 26, wherein said electrical-optical converter comprises:

at least two electrical-optical conversion units each converting one of said at least two signals modulated by said modulator into an optical signal for transmission from said transmitting unit.

33. An apparatus according to claim 32, wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said optical signals received and guided by said second light guide into respective electric signals; and

a selection unit for selecting at least two of said electric signals having a maximum signal amplitude and supplying said selected electric signals to said demodulator.

34. An apparatus according to claim 33, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

35. An apparatus according to claim 33, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

36. An apparatus according to claim 33, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

37. An apparatus according to claim 33, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

38. An apparatus according to claim 26, wherein said first and second light guides attenuate said optical signal at levels different from each other.

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

a first filter for filtering said optical signal from said first light guide prior to transmission of said optical signal to said receiving unit; and

a second filter for filtering said optical signal transmitted from said first light guide prior to receiving said optical signal in said second light guide.

40. An apparatus for transmitting an optical signal representing at least two of video, audio, control and digital data signals from a transmitting unit to a receiving unit, comprising:

a modulator for modulating each of said at least two signals;

a multiplexer for frequency-multiplexing said at least two signals modulated by said modulator;

an electrical-optical converter for converting the signal obtained by multiplexing in said multiplexer into an optical signal;

a light guide for spatially emitting said optical signal from said transmitting unit to said receiving unit;

a filter for filtering said optical signal from said light guide prior to emission from said transmitting unit to said receiving unit;

an optical-electrical converter for receiving said spatially emitted optical signal filtered by said filter and converting said received optical signal into an electric signal; and

a demodulator for demodulating said electric signal obtained by conversion in said optical-electrical converter thereby obtaining said at least two signals.

41. An apparatus according to claim 40, wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said received optical signal into respective electric signals; and

a selection unit for selecting one of said electric signals having a maximum signal amplitude and supplying said selected electric signal to said demodulator.

42. An apparatus according to claim 41, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

43. An apparatus according to claim 41, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

44. An apparatus according to claim 43, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

45. An apparatus according to claim 41, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

46. An apparatus according to claim 40, wherein said electrical-optical converter comprises:

at least two electrical-optical conversion units each converting one of said at least two signals modulated by said modulator into an optical signal for transmission from said transmitting unit.

47. An apparatus according to claim 46, wherein said optical-electrical converter comprises:

a plurality of optical-electrical conversion units for converting said received optical signals into respective electric signals; and

a selection unit for selecting at least two of said electric signals having a maximum signal amplitude and supplying said selected electric signals to said demodulator.

48. An apparatus according to claim 47, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the video signal included in the electric signal is maximum or not.

49. An apparatus according to claim 47, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the audio signal included in the electric signal is maximum or not.

50. An apparatus according to claim 47, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the control signal included in the electric signal is maximum or not.

51. An apparatus according to claim 47, wherein said selection circuit, when selecting an electric signal having a maximum signal amplitude from the plurality of electric signals, determines whether the signal amplitude is maximum or not according to whether the signal amplitude of the digital data included in the electric signal is maximum or not.

52. An apparatus according to claim 40, wherein said light guide attenuates said optical signal at a predetermined level.

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

a filter for filtering said optical signal transmitted from said light guide prior to receiving said optical signal in said optical-electrical converter.