Sony Corporation

Yasuyuki Takeshita

Keiichi Tsutsui

Kazuhiko Fujiie

Atsushi Fukumoto

Taiji Ito

Takashi Nakao

Motoi Kimura

Shinichi Kai

Takeshi Sano

Keiichi Shibata

Tamotsu Ishii

Shinji Ohta

Mitsuhiro Ueno

Kyohei Iwamoto

Hiromitsu Komatsu

Hidetaka Kodama

An optical communication device, for performing communication between spatially separated points by using one or more laser beams, includes an angle correction device that corrects a direction of a light receiving system and an emission optical axis correction device, in which an angle error which is not corrected by the angle correction device is detected by a light receiving angle detection device, and the emission optical axis correction device is controlled according to a detected error amount, and an emission optical axis is corrected.

Optical communication device

A laser drive includes a variable output voltage source that can control an output voltage, a laser source connected to the variable output voltage source, a laser drive circuit that drives the laser source, and a monitoring controller that monitors an operating voltage of the laser drive circuit and controls the output of the variable output voltage source such that the monitored operating voltage becomes equal to a desired value.

Laser drive, optical disc apparatus, and laser-driving method

The present invention proposes a method of controlling the laser power of a semiconductor laser that, in this method of controlling the laser power of a semiconductor laser by applying a power source voltage to between the collector and emitter of an output transistor and a serial circuit of the output transistor and a semiconductor laser, enables decreasing the power consumption of the output transistor. The present invention is arranged to apply a variable power source voltage Vcc to a serial circuit of an output transistor (Qb) and a semiconductor laser (SL) and thereby control the variable power source voltage Vcc such that a difference between the variable power source voltage Vcc and the peak hold voltage of an operating voltage of the semiconductor laser (SL) becomes substantially constant.

Optical recording, producing apparatus, and method with peak-hold voltage features

A liquid crystal device, and a method and an apparatus for driving the same in which the refractive index of the liquid crystal device is adjusted using a simple driving method and apparatus, which is advantageous in that the cost is reduced, are provided. A liquid crystal device () includes a first transparent substrate () and a second transparent substrate () that face each other, a liquid crystal () filled between the first and second transparent substrates (), a first transparent electrode () formed on a surface of the first transparent substrate () that faces the second transparent substrate (), and a second transparent electrode () formed on a surface of the second transparent substrate () that faces the first transparent substrate (). First and second driving signals (S, S) of square waves are applied to the first and second transparent electrodes () with a time interval t (sec) therebetween. Thus, the potential difference between the first and second driving signals (S, S) is applied to the liquid crystal ().

Liquid crystal device, its driving method, and driving apparatus

A reproducing laser output can be adjusted to an optimal level. To this end, a magneto-optical disk device includes a differential amplifier and a shortest recording mark identifier that detects a shortest recording mark reproducing signal corresponding to a component of a shortest recording mark in a reproducing signal obtained by reproducing a magneto-optical disk. In addition, an envelope detector detects an amplitude level of the shortest recording mark reproducing signal, a comparator compares the amplitude level with a reference voltage outputted from the reference voltage source, and a drive control section adjusts the reproducing laser beam to an output level at which the amplitude level is equal to or higher than the reference voltage, based on a comparison result from the comparator.

Optical output adjusting apparatus based on shortest recording marks

Growing community of inventors

Tokyo, Japan

Yasuyuki Takeshita