Digital image sender, digital image receiver, digital image transmission system and digital image transmission method

A digital image sender for transmitting a digital image signal including image signals for color image reproduction, a reference clock signal and parallel control signals, comprising:

• parallel/serial conversion means for converting the parallel control signals into a serial control signal by time division multiplexing;
• superposition means for superposing the serial control signal obtained by the conversion by said parallel/serial conversion means and the reference clock signal and outputting a resulting superposition signal, wherein the superposition signal is formed by combining individual optical element driving currents respectively associated with the serial control signal and reference clock which are simultaneously applied to an electro-optic conversion means;
• and further wherein the reference clock and parallel control signals are converted via a single electrooptic converter into an optical signal, and wherein an amplitude controller receives the reference clock and serial control signal and provides outputs such that an amplitude of the reference clock has a predetermined relationship to an amplitude of the serial control signal and the amplitude controller provides an output corresponding to the reference clock to an optical element driver having a current signal output and the amplitude controller provides an output to a transistor that controls a further current that is combined with the optical element driver current signal output in order to drive the optical element with the combined current.

A digital image receiver for receiving a digital image signal, which includes image signals for color image reproduction, a reference clock signal and parallel control signals, in the form of an optical signal produced by an electro-optic conversion of a superposition signal wherein a serial control signal converted from the parallel control signals by time division multiplexing and the reference clock signal are superimposed, comprising:

• an opto-electric converter configured to convert the received superposition signal from an optical signal into an electric signal, wherein the superposition signal is formed by combining individual optical element driving currents respectively associated with the control signals and reference clock which are simultaneously applied to a transmission electro-optic converter;
• a separator configured to separate the superposition signal converted by said opto-electric converter into the reference clock signal and the serial control signal;
• and
• a serial/parallel converter configured to convert the serial control signal separated by said separator into parallel control signals by time division demultiplexing and a clock signal which are derived from a common optical signal.

A digital image receiver for receiving a digital image signal, which includes image signals for color image reproduction, a reference clock signal and parallel control signals, in the form of an optical signal produced by electro-optic conversion of a superposition signal wherein a serial control signal converted from the parallel control signals by time division multiplexing and the reference clock signal are superimposed, comprising:

• opto-electric conversion means for converting the received superposition signal from an optical signal into an electric signal, wherein the superposition signal is formed by combining individual optical element driving currents respectively associated with the serial control signal and reference clock which are simultaneously applied to a transmission electrooptic converter;
• separation means for separating the superposition signal converted by said opto-electric conversion means into the reference clock signal and serial control signal;
• and
• serial/parallel conversion means for converting the serial control signal separated by said separation means into parallel control signals by time division demultiplexing, and further wherein the reference clock and parallel control signals are converted from a single optical signal.

A digital image transmission system, comprising:

• a digital image sender which transmits a digital image signal including image signals for color image reproduction, a reference clock signal and parallel control signals;
• and
• a digital image receiver which receives the digital image signal from said digital image transmission apparatus;
• said digital image sender including
• a parallel/serial converter configured to convert the parallel control signals into a serial control signal by time division multiplexing,
• a superposition element configured to superimpose the serial control signal obtained by the conversion by said parallel/serial converter with the reference clock signal and output a resulting superposition signal, wherein the superposition signal is formed by combining individual optical element driving currents respectively associated with the serial control signal and reference clock which are simultaneously applied to an electrooptic converter, and wherein an amplitude controller receives the reference clock and serial control signal and provides outputs such that an amplitude of the reference clock has a predetermined relationship to an amplitude of the serial control signal and the amplitude controller provides an output corresponding to the reference clock to an optical element driver having a current signal output and the amplitude controller provides an output to a transistor that controls a further current that is combined with the optical element driver current signal output in order to drive the optical element with the combined current and
• the electro-optic converter configured to convert the superposition signal outputted from said superposition element from an electric signal into an optical signal;
• said digital image receiver including
• an opto-electric converter configured to convert the received superposition signal from an optical signal into an electric signal,
• a separator configured to separate the superposition signal converted by said opto-electric converter into the reference clock signal and the serial control signal, and
• a serial/parallel converter configured to convert the serial control signal separated by said separator into parallel control signals by time division demultiplexing, and further wherein the reference clock and parallel control signals are converted from a single optical signal.

A digital image transmission method for transmitting a digital image signal including image signals for color image reproduction, a reference clock signal and parallel control signals, comprising the steps executed on the sender side of the digital image signal of:

• converting the parallel control signals into a serial control signal by time division multiplexing;
• superposing the serial control signal obtained by the conversion with the reference clock signal and wherein an amplitude controller receives the reference clock and serial control signal and provides outputs such that an amplitude of the reference clock has a predetermined relationship to an amplitude of the serial control signal and the amplitude controller provides an output corresponding to the reference clock to an optical element driver having a current signal output and the amplitude controller provides an output to a transistor that controls a further current that is combined with the optical element driver current signal output in order to drive the optical element with the combined current;
• and
• converting the superposition signal from an electric signal into an optical signal, wherein the superposition signal is formed by combining individual optical element driving currents respectively associated with the serial control signal and reference clock which are simultaneously applied to an electrooptic converter;
• and the steps executed on the receiver side of the digital image signal of:
• converting the received superposition signal from an optical signal into an electric signal;
• separating the superposition signal obtained by the conversion into the reference clock signal and the serial control signal;
• and
• converting the separated serial control signal into parallel control signals by time division demultiplexing, and further wherein the reference clock and parallel control signals are converted from a single optical signal.