Optical transmission of signals
First Claim
1. An optical transmitter, comprising:
- signal processing means for respectively modulating a plurality of electrical signals and providing respective modulated signals in a plurality of respective frequency bands with at least one of said modulated signals having sideband waves at opposite sides of the respective frequency band;
means for removing one of said sideband waves from said at least one of the modulated signals having sideband waves at opposite sides of the respective frequency band; and
electro-optical transducing means for transducing said at least one modulated signal from which said one sideband wave has been removed, and for transducing another of said modulated signals in said plurality of frequency bands into respective optical signals.
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Accused Products
Abstract
In optically transmitting a video signal comprised of luminance and chrominance signals which are frequency modulated to provide an FM luminance signal and an FM chrominance signal in respective adjacent frequency bands, such as, 6 to 20 MHz and 20 to 30 MHz, respectively, whereupon, infrared signals corresponding to the FM luminance and chrominance signals are output by respective emitting diodes, a carrier frequency for the FM chrominance signal is set, for example, between 25.93 and 26.08 MHz, so that the lower sideband wave of the FM chrominance signal is spaced by a substantial frequency from a frequency band in which a secondary distortion of the FM luminance signal is substantially generated. Further, the upper sideband wave of the FM chrominance signal is removed, as in a trap circuit, for ensuring that the transmitted FM chrominance signal will be accommodated in the respective frequency band therefor when its carrier frequency is set, as above. When the infrared signals corresponding to the FM luminance and chrominance signals are received by a photodiode and thereby transduced to respective FM modulated components output by the photodiode and then preamplified in common prior to separation, the component corresponding to the FM chrominance signal has the removed upper sideband wave restored by amplitude limiting thereof.
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Citations
20 Claims
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1. An optical transmitter, comprising:
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signal processing means for respectively modulating a plurality of electrical signals and providing respective modulated signals in a plurality of respective frequency bands with at least one of said modulated signals having sideband waves at opposite sides of the respective frequency band; means for removing one of said sideband waves from said at least one of the modulated signals having sideband waves at opposite sides of the respective frequency band; and electro-optical transducing means for transducing said at least one modulated signal from which said one sideband wave has been removed, and for transducing another of said modulated signals in said plurality of frequency bands into respective optical signals. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An optical transmission method, comprising:
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modulating a plurality of electrical signals so as to provide respective modulated signals in a plurality of respective frequency bands with at least one of said modulated signals having sideband waves at opposite sides of the respective frequency band; removing a sideband wave from said at least one of the modulated signals having sideband waves at opposite sides of the respective frequency band; and electro-optically transducing said at least one modulated signal from which said one sideband wave has been removed and another of said modulated signals in said plurality of frequency bands into respective optical signals. - View Dependent Claims (8, 9, 10)
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11. An optical transmission system comprising:
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an optical transmitter including signal processing means for respectively modulating a plurality of input electrical signals and providing respective modulated input signals in a plurality of respective frequency bands with at least one of said modulated input signals having sideband waves at opposite sides of the respective frequency band, means for removing one of said sideband waves from said at least one of the modulated input signals having sideband waves at opposite sides of the respective frequency band, and transmitting electro-optical transducing means for transducing said at least one modulated input signal from which said one sideband wave has been removed and for transducing another of said modulated input signals in said plurality of frequency bands into respective transmitted optical signals; and an optical receiver including receiving electro-optical transducing means for receiving said transmitted optical signals and for transducing the received optical signals into a corresponding electrical output, means for preamplifying said electrical output, filter means for extracting from the preamplified electrical output said respective frequency bands and thereby providing respective modulated received signals, means for restoring said one of the sideband waves to the modulated received signal corresponding to the modulated input signal from which said one sideband wave was removed, and means for demodulating said respective modulated received signals so as to provide respective output electrical signals corresponding to said input electrical signals, respectively. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An optical transmitter for a video signal including at least a luminance signal and a chrominance signal, said transmitter comprising:
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signal processing means for frequency modulating said luminance signal and said chrominance signal so as to provide a modulated luminance signal in a first frequency band and a modulated chrominance signal in a second frequency band which is higher than and adjacent to said first frequency band, with said modulated chrominance signal having primary lower and upper sideband waves at opposite sides of said second frequency band; means for removing said upper sideband wave from said modulated chrominance signal; and electro-optical transducing means for transducing said modulated chrominance signal from which said upper sideband wave has been removed, and for transducing said modulated luminance signal. - View Dependent Claims (18, 19, 20)
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Specification