Sony Corporation

Sony Disc & Digital Solutions Inc.

Koji Ishiwata

Satoru Tobita

Masaru Tezuka

Toshiharu Kondo

Hideo Kawachi

Teruhito Noshiro

Kunio Nakayama

Cheonseok Park

A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.

Laser control method and laser control circuit

A disc recording/playback apparatus adapted to obtain data of recorded signals at the maximum level within a predetermined period in the signal recorded on an erasable medium per each predetermined period from a signal recording start point to end point and to record them as waveform data of the recorded signal in a different recording area from that of the recorded signal. A compressed envelope waveform of the recorded signal may be displayed on a display section by supplying the waveform data continuously to the display section, so that broad signal changes can be understood by viewing them.

Method and apparatus for recording signals with sub-signals indicative

In a reproducing system, a reproducing start position of recording information is set in a first reproducing device reproducible in a second reproducing device. The reproducing start position set in the first reproducing device is stored in a detachable external storage medium. The external storage medium is detached from the first reproducing device, attached to a second reproducing device, and the reproducing start position stored in the external storage medium is read into the second reproducing device. Thus the reproducing start position set by the first reproducing device will be reproduced in the second reproducing device to control a location of selection, such as musical numbers.

Reproducing system with detachable storage medium for storing selected

An apparatus for recording a signal on a disc medium driven by a servo circuit comprises, device for generating a laser beam for recording the signal on the disc medium, device for detecting a track jump of a scan of the disc medium by the laser beam, device for storing the signal during an occurrence of the track jump, and controller for controlling the laser beam generating device, track jump detecting device and storing device so that a recording operation by the laser beam is stopped during the occurrence of the track, and the signal stored in the storing device is recorded on a predetermined area of the disc medium after the record operation becomes to be possible.

Disc recording apparatus for recording a signal without losing the

An optically writable record of digital information is provided on an optically writable record disk having a reflection factor substantially higher than seventy percent, and is composed of first digital information including a plurality of program data and respective address data indicative of the individual addresses of the respective program data and being recorded with the latter sequentially along a first track in a first annular recording area of the record disk, and second digital information including table-of-contents data, identifying the plurality of program data, respectively, and being recorded sequentially along a second track which is in a second annular recording area of the record disk and which has a concluding end contiguous to a starting end of the first track so that, upon playback of the digital information record, the table-of-contents data and the plurality of program data and respective address data can be reproduced successively without interruption by a standardized compact disk player.

Growing community of inventors

Kanagawa, Japan

Koji Ishiwata