Sony Corporation

Jumpei Kura

Tatsuya Tamaki

Shunji Yoshimura

Motoi Kimura

Takeshi Yuwaki

Toshiki Shimizu

Seiichi Sagara

Naoyuki Nishigata

Mariko Fukuyama

Takashi Fujimoto

Tadatsugu Morimoto

Yoshie Hayashida

Rumi Fukuda

A reproduction signal output from a reproduction device is output via a relay device to two or more display devices including an excellent display device that is used by being mounted on the head of a user. A connection monitoring circuit in a front end boxmonitors both a +5V signal of a source appliance that is HDMI-connected to an HDMI input unit, and an HPD signal of a sink appliance that is HDMI-connected to a second output unit. Then, only when an HPD signal emitted by the HDMI sink appliance is detected together with a +5V signal emitted by the HDIM source appliance does the connection monitoring circuit in the front end boxenables a repeater function with respect to the HDMI sink appliance.

Display system, display device, and relay device

A recording and reproducing apparatus includes optical head means for writing and reading information expressed by a mark and a space on an optical recording medium by irradiating laser light to the optical recording medium, laser-drive pulse generating means for creating and supplying a laser-driving pulse in accordance with information to write to the optical head means and causing the optical head means to perform the irradiation of laser light for writing, mark edge error detecting means for detecting an error of the edge position of the mark from a signal read out from the optical recording medium by the optical head means; and adjustment control means for defining the adjustment on a laser-driving pulse generated by the laser-driving pulse generating means.

Recording and reproducing apparatus and laser-driving pulse adjusting method

An optical recording and reproducing apparatus includes a recording-pulse-shift setting unit that shifts a front edge and a rear edge of a recording pulse and sets a write strategy of the recording pulse, an mark-edge-position evaluating unit that detects a front edge and a rear edge of a mark formed and detects a front mark edge position error and a rear mark edge position error, an assuming unit that assumes that the front mark edge position error is represented by a first linear function and assumes that the rear mark edge position error is represented by a second linear function, a sensitivity calculating unit that executes test recording and calculates sensitivities, and a write-strategy calculating unit that calculates a write strategy of the recording pulse on the basis of the sensitivities.

Optical recording and reproducing apparatus and optical recording and reproducing method

An evaluation value calculating apparatus includes the following elements. A difference metric selecting unit selects a difference metric for a specific recorded sequence in recorded sequences obtained in a maximum likelihood decoding process when information expressed with marks and spaces on a recording medium is played back, the difference metric being obtained in the maximum likelihood decoding process. A difference metric error value calculating unit determines a difference metric error value for the selected difference metric using a calculation method that is selected according to an edge shift direction of each of the marks on a time axis, the difference metric error value representing an error from an ideal difference metric and the edge shift direction on the time axis. A statistical processing unit performs statistical processing on the determined difference metric error value on the basis of each of states of path meeting points to generate an evaluation value.

Evaluation value calculating apparatus, recording and playback apparatus, evaluation value calculating method, recording method

An optical disk recording apparatus having () an optical pickup that emits laser light to illuminate a recording surface of an optical disk, receives reflected light resulting from the laser light reflected off the recording surface, and generates a light reception signal based on the thus received reflected light; () a laser power controller that sets a laser power setting and controls the power of the laser light emitted from the optical pickup based on the thus set laser power setting; and () a signal generator that, when a plurality of trial write areas provided on the recording surface of the optical disk are successively illuminated with the laser light in order to write trial write data, generates a timing notification signal that sets laser arrival timing when the laser light sequentially reaches trial write start positions of the plurality of trial write areas based on the light reception signal generated by the optical pickup.

Optical disk recording apparatus and optical recording method

A laser driving apparatus for a light source of an optical head apparatus includes a laser, a laser driving circuit, and a radio frequency current generation circuit for generating a radio frequency current to be superimposed on the drive current. The laser driving apparatus further includes a current monitor circuit, an optical detector for detecting an optical output of the laser; a selection circuit for selecting either of non-superimposing or superimposing the radio frequency current on the drive current, an APC circuit for controlling the optical output of the laser at a constant level, and a control circuit. The control circuit controls the amplitude of the radio frequency current on the basis of current values of the drive current on non-superimposing and superimposing or detection values of the optical output of the laser on non-superimposing and superimposing.

Laser driving apparatus and associated methodology of controlling a drive current

A digital signal reproducing circuit which enables precise measurement of a phase difference and jitter components of reproduction signals while realizing miniaturization of the circuit is disclosed. The digital signal reproducing circuit has a phase comparator for detecting a phase difference by using sampled values before and after an edge portion of a reproduction signal from an optical disc outputted from an A/D converter, and a jitter measuring section for detecting a jitter detection signal on the basis of unevenness of the phase difference obtained by the phase comparator.

Digital signal reproducing circuit

The present invention provides a digital signal reproduction circuit capable of controlling a transfer function of waveform equalization circuit so that a synchronous clock can be generated with an optimal transfer characteristic. The digital signal reproduction circuit 1 includes: a waveform equalization block for waveform-equalizing a regenerative signal; a binarization block 20 for binarizing the regenerative signal which has been waveform-equalized; a synchronous clock reproduction block 30 for generating a synchronous clock from the signal binarized; and a waveform equalization control block 40 for controlling a transfer function of the waveform equalization block 10 according to a jitter component between the synchronous clock and the binarized signal. The waveform equalization control block 40 is supplied with a phase difference signal between the binarized signal and the synchronous signal, so as to obtain an optimal value of the transfer function of the waveform equalization block 10 by using a microcomputer, for example. The transfer function is controlled so as to reduce the jitter component of the synchronous clock.

Growing community of inventors

Kanagawa, Japan

Jumpei Kura