Abstract: There is provided a display device equipped with a display unit, the display device including a receiving part for receiving a difference signal of a plurality of channels including an image signal and content identification information inserted in a blanking period and outputting the image signal and the content identification information; a light emission amount regulation part for setting a reference duty according to image information of the image signal; an adjustment part for adjusting so that an actual duty is within a predetermined range based on the reference duty and an adjustment signal and adjusting a gain of the image signal so that a light emission amount defined by the actual duty and the gain of the image signal becomes the same as the light emission amount defined by the reference duty; and an adjustment signal generation part for generating the adjustment signal based on the content identification information.

Abstract: An optical reception device realizes stabilization of reception sensitivity inexpensively and highly precisely. The optical reception device includes: a Mach-Zehnder type 1-bit delay unit including a one-terminal input port and two-terminal output ports for decoding an optical difference phase shift keying (DPSK) signal and provided with one or more phase control functions to control the phase state of light; photoelectric conversion means for branching a portion of an optical output signal output from the one-side output port of the Mach-Zehnder type 1-bit delay unit, to convert the branched portion into an electric signal; and a phase control unit for controlling the phase state of the Mach-Zehnder type 1-bit delay device by using as an error signal the output signal of the photoelectric conversion means.

Abstract: An optical divider divides an optical input signal into a plurality of paths. A plurality of optical-to-electrical converters respectively converts the divided optical input signals into electrical signals. A plurality of discriminators respectively outputs discrimination results by discriminating the electrical signals output from the optical-to-electrical converters based on predetermined thresholds. An operational circuit performs a predetermined logical operation with the discrimination results output from the discriminators.

Abstract: An error correction coding apparatus includes a first coding unit for coding a sequence data to be coded which includes information source data for each frame to generate an error correcting code word sequence including a parity sequences, and a first rearranging unit for rearranging elements of the error correcting code word sequences of a plurality of frames generated by the first coding unit. The first rearranging unit rearranges elements of the parity sequences included in the error correcting code word sequences. The first rearranging unit also rearranges elements of the error correcting code word sequences other than the parity sequences, within the error correcting code word sequences other than the parity sequences.

Abstract: A repeater includes a variable optical attenuating unit that collectively attenuates WDM optical signal input, an optical-attenuation adjusting unit that adjusts attenuation in the variable optical attenuating unit, and an optical amplifying unit that collectively amplifies and outputs the WDM optical signal collectively attenuated, to a downstream side. An optical-attenuation adjusting unit includes an input level detector; an output level detector; an output-level transmitting unit that receives information of a signal level of WDM optical signal output by a repeater at an upstream side and transmits information of a signal level of the WDM optical signal detected by the output level detector to a repeater at a downstream side; and an attenuation amount controller that controls the variable optical attenuating unit by calculating an attenuation amount thereof based on information of a signal level detected by the input level detector and a signal level received by the output-level transmitting unit.

Abstract: A control-target-value setting unit sets a control target value corresponding to the number of multiplexed wavelengths measured by a number-of-multiplexed-wavelengths measuring unit. A controller controls the variable optical attenuator based on the control target value. An optical amplifier performs an optical amplification with a constant gain regardless of power of a wavelength-multiplexed light. The controller performs feedback control of the variable optical attenuator such that a result of measurement of the total power of the wavelength-multiplexed light coincides with the control target value.

Abstract: An optical transmitter includes an optical modulator, an optical coupler, a crosspoint monitoring unit, a reference-value setting unit, and a bias circuit. The optical coupler splits an optical signal output from the optical modulator into a plurality of optical signals. The crosspoint monitoring unit receives part of the optical signals, and monitors a crosspoint of the optical signal output from the optical modulator. The reference-value setting unit sets a bias reference value to be assigned to the optical modulator based on an output of the crosspoint monitoring unit so that the crosspoint is constant. The bias circuit applies a bias to the optical modulator based on the bias reference value.

Abstract: A Raman amplifier includes a pumping light source, an optical coupler, and a Raman amplifier medium. The pumping light source outputs a pumping light that is intensity-modulated with a frequency equal to or higher than 100 megahertz. The optical coupler couples the pumping light with a carrier light. The Raman amplification medium is pumped by the pumping light to amplify the carrier light. The Raman amplification medium has characteristics of a low dispersion and a small difference between propagation times of the carrier light and the pumping light.

Abstract: [Object] To make it possible for the reception side to carry out an optimum process for an image signal (image data) depending upon the type of a content. [Solving Means] An AV system 40 composed of an HD recorder 41 and a display unit 42 uses a communication interface of the HDMI. An HDMI source 53 of the HD recorder 41 transmits image data (image signal) in the form of differential signals to an HDMI sink 61 of the display unit 42 through three TMDS channels. The HDMI source 53 inserts content identification information for the identification of the type of a content of image data to be transmitted into an AVI InfoFrame packet placed in a blanking period. A control section 64 of the display unit 42 controls operation of a display processing section 62 which carries out a process for displaying for the image data based on the content identification information (ITC, CT1 and CT0) received by the HDMI sink 61 and a display section 63 for displaying an image.

Abstract: There is provided a display device equipped with a display unit, the display device including a receiving part for receiving a difference signal of a plurality of channels including an image signal and content identification information inserted in a blanking period and outputting the image signal and the content identification information; a light emission amount regulation part for setting a reference duty according to image information of the image signal; an adjustment part for adjusting so that an actual duty is within a predetermined range based on the reference duty and an adjustment signal and adjusting a gain of the image signal so that a light emission amount defined by the actual duty and the gain of the image signal becomes the same as the light emission amount defined by the reference duty; and an adjustment signal generation part for generating the adjustment signal based on the content identification information.

Abstract: A bias circuit that supplies bias voltage or bias current to one end of a transmission line includes an inductor that prohibits a high frequency component of a baseband signal transmitted on the transmission line and passes a frequency component near direct current of the baseband signal, and an impedance-decrease prevention element that prevents impedance from decreasing, when viewed from the transmission line, that is produced due to a resonance between a parasitic capacitance generated due to the inductor and an inductance of the inductor.

Abstract: An optical reception device realizes stabilization of reception sensitivity inexpensively and highly precisely. The optical reception device includes: a Mach-Zehnder type 1-bit delay unit including a one-terminal input port and two-terminal output ports for decoding an optical difference phase shift keying (DPSK) signal and provided with one or more phase control functions to control the phase state of light; photoelectric conversion means for branching a portion of an optical output signal output from the one-side output port of the Mach-Zehnder type 1-bit delay unit, to convert the branched portion into an electric signal; and a phase control unit for controlling the phase state of the Mach-Zehnder type 1-bit delay device by using as an error signal the output signal of the photoelectric conversion means.

Abstract: A wavelength demultiplexer demultiplexes a wavelength multiplexed incident photon pulse string based on wavelengths of the photons in the photon pulse string. Each of a plurality of photon detectors detects a photon that is demultiplexed by the wavelength demultiplexer and outputs a signal based on detected photon, and a bias applying unit applies a gate pulse as a bias voltage to at least some of the photon detectors to match an incidence timing of an output light of the wavelength demultiplexer to the photon detectors. A data processor converts the signals from the photon detectors into time series signals.

Abstract: An optical transmitter includes an optical modulator, an optical coupler, a crosspoint monitoring unit, a reference-value setting unit, and a bias circuit. The optical coupler splits an optical signal output from the optical modulator into a plurality of optical signals. The crosspoint monitoring unit receives part of the optical signals, and monitors a crosspoint of the optical signal output from the optical modulator. The reference-value setting unit sets a bias reference value to be assigned to the optical modulator based on an output of the crosspoint monitoring unit so that the crosspoint is constant. The bias circuit applies a bias to the optical modulator based on the bias reference value.

Abstract: An error correction coding apparatus includes a frame generating unit for buffering inputted information sequence data in frame buffers which correspond to units to be coded, respectively, a first interleaving unit for rearranging the information sequence data within two or more of the frame buffers, a first coding unit for coding the information sequence data rearranged by the first interleaving unit for each of the frame buffers, and for buffering an error correcting code generated thereby in the frame buffer, a first deinterleaving unit for rearranging code word sequence data in the frame buffer which is coded by the first coding unit according to a procedure which is reverse to that which the first interleaving unit uses, and a multiplexing unit for outputting, as transmission information, the code word sequence data rearranged by the first deinterleaving unit.

Abstract: A bias circuit that supplies bias voltage or bias current to one end of a transmission line includes an inductor that prohibits a high frequency component of a baseband signal transmitted on the transmission line and passes a frequency component near direct current of the baseband signal, and an impedance-decrease prevention element that prevents impedance from decreasing, when viewed from the transmission line, that is produced due to a resonance between a parasitic capacitance generated due to the inductor and an inductance of the inductor.

Abstract: A Raman amplifier includes a pumping light source, an optical coupler, and a Raman amplifier medium. The pumping light source outputs a pumping light that is intensity-modulated with a frequency equal to or higher than 100 megahertz. The optical coupler couples the pumping light with a carrier light. The Raman amplification medium is pumped by the pumping light to amplify the carrier light. The Raman amplification medium has characteristics of a low dispersion and a small difference between propagation times of the carrier light and the pumping light.

Abstract: A phase comparator includes: first and second detecting units for detecting an amplitude value of a clock signal at falling timing or rising timing of a data signal; an edge comparing unit for identifying as to whether the first detecting unit detects an amplitude value under a rising state or a falling state to output a first identification result, and for identifying as to whether the second detecting unit detects an amplitude value under a rising state or a falling state to output a second identification result; first and second polarity inverting units for inverting a polarity of output of the first and second detecting units; and a signal selecting unit for selecting one of output values of the first and second polarity inverting units in response to a polarity of the data signal to output the selected output value.

Abstract: An optical divider divides an optical input signal into a plurality of paths. A plurality of optical-to-electrical converters respectively converts the divided optical input signals into electrical signals. A plurality of discriminators respectively outputs discrimination results by discriminating the electrical signals output from the optical-to-electrical converters based on predetermined treshholds. An operational circuit performs a predetermined logical operation with the discriminators.

Abstract: An optical receiver includes a soft-decision deciding unit (7) for deciding an electric received signal according to a plurality of decision levels to output a multivalued decision signal, a demultiplexing unit (5) for serial-to-parallel converting the multivalued decision signal to output a multivalued parallel signal, a soft-decision error correction decoding unit (8) for correcting the multivalued parallel signal based on reliability information to output an error-corrected parallel received signal and decision results indicating the decision of the electric received signal according to the plurality of decision levels, a probability density distribution estimation unit (9) for estimating probability density distributions based on distributions of the decision results, and a decision level control unit (10) for controlling the plurality of decision levels based on the probability density distributions, thereby improving the transmission quality.