Optical transmission/reception system for various video signals
View Patent ↗A special-code encoding circuit generates a first special code to be added to a video signal and a second special code to replace a synchronous signal. A multiplex circuit multiplexes the video signal and first and second special codes. An encoding circuit for code conversion performs 8B/10B encoding. A parallel/serial conversion circuit converts parallel data to serial data (bit stream signal). A light emission circuit and a light emission device transmit the bit stream signal as a light signal.
1. An optical transmission apparatus for use in an optical transmission/reception system in which an electric signal comprising a digital signal including at least a video signal and horizontal and vertical synchronous signals of the video signal is converted to a light signal and then transmitted and in which the light signal is received and converted to the electric signal comprising the digital signal, the apparatus comprising:
a first encoder for generating at least a first identification code indicating presence of both the horizontal synchronous signal and the vertical synchronous signal, a second identification code indicating presence of the horizontal synchronous signal, a third identification code indicating presence of the vertical synchronous signal, and a fourth identification code indicating a start position of the video signal;
a multiplexer for multiplexing the video signal and the first to fourth identification codes while arranging the fourth signal ahead of the video signal to output a signal obtained by the multiplexing as a first data string which has a first bit number;
a second encoder for converting an output of the multiplexer to a second data string which has a second bit number larger than the first bit number;
a bit stream converter for converting the second data string to a bit stream signal; and
a light emitter for transmitting the bit stream signal as the light signal.
2. The optical transmission apparatus according to claim 1 , further comprising:
a format converter, disposed in a stage before the first encoder, for format-converting the video signal to decrease or increase a number of lines or pixels of the video signal.
3. The optical transmission apparatus according to claim 1 , wherein the optical transmission/reception system conforms to IEEE802.3z standard of measure, and the second encoder includes an 8B/10B encoding circuit for encoding the first data string of eight bits to the second data string of ten bits.
4. An optical reception apparatus for use in an optical transmission/reception system in which an electric signal comprising a digital signal including at least a video signal and horizontal and vertical synchronous signals of the video signal is converted to a light signal and then transmitted and in which the light signal is received and converted to the electric signal comprising the digital signal, the apparatus comprising:
light receiver for receiving the light signal and converting the light signal to an electric bit stream signal, the light signal being based on a bit stream signal obtained by conversion of a first data string having a first bit number, the first data string being obtained by conversion of a second data string having a second bit number equal to or smaller than the first bit number, the second data string being obtained by multiplexing the video signal, a first identification code indicating presence of both the horizontal synchronous signal and the vertical synchronous signal, a second identification code indicating presence of the horizontal synchronous signal, a third identification code indicating presence of the vertical synchronous signal, and a fourth identification code arranged ahead of the video signal and indicating a start position of the video signal;
a converter for converting the electric bit stream signal to the first data string;
a first decoder for converting an output of the converter to the second data string; and
a second decoder for separating the video signal based on the first fourth identification code included in the second data string and generating the horizontal and vertical synchronous signals based on the first, second and third identification codes.
5. The optical reception apparatus according to claim 4 , wherein the optical transmission/reception system conforms to IEEE802.3z standard of measure, and the first decoder includes an 8B/10B decoding circuit for decoding the first data string of ten bits to the second data string of eight bits.