Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Tatsuo Suzuki

Akihiro Hatsusegawa

Katsuya Watanabe

Masanobu Takahashi

Katsuo Hori

Toshihiko Iga

Naoko Suzuki

A signal processing device for optical disks includes a reflected light process section configured to convert reflected light received by an optical pickup into an electric signal based on a first gain, wherein the optical pickup emits laser light to an optical disk and receives reflected light from the optical disk; a servo signal generation section configured to generate a servo signal by using the electric signal generated by the reflected light process section; a servo signal control section configured to control the servo signal so that a change in the amplitude of the servo signal, in response to an increase or decrease of the amount of the reflected light from the optical disk, is suppressed using an attenuator that attenuates the servo signal generated by the servo signal generation section by a factor of a second gain; and a gain setting section configured to set the first gain to the reflected light process section and the second gain to the servo signal control section substantially simultaneously.

Signal processing device for optical disks and optical disk apparatus

An information processing apparatus according to the present invention comprises a communication device, a volatile memory for storing a communication data therein, a first CPU for controlling communication processings of the communication device and the communication data stored in the volatile memory, a ROM memory in which a program of the first CPU is previously stored, a second CPU for controlling the whole apparatus, a non-volatile memory for storing a whole program of the second CPU therein, a ROM memory in which another program executable by the second CPU is previously stored; and an external input terminal adapted in such a manner that if program execution by the second CPU starts in the non-volatile memory or in the ROM memory is selectively set, wherein where the program execution starts is selected in accordance with the setting of the external input terminal when activated, and a rewriting program for the whole program of the non-volatile memory is stored in the ROM memory.

Information processing apparatus

A transfer start/end detecting section detects timing at which a DMARQ signal becomes an H level or an L level. A transfer time-measuring section measures a transfer time during which data transfer is actually performed within a period in which a predetermined number of data blocks are transferred. A transfer byte count-measuring section measures a transferred byte count of data that have successfully been transferred. An effective data transfer rate-computing section computes an effective data transfer rate by dividing the transferred byte count by the transfer time. A transfer rate-comparing section compares the effective data transfer rate with a transfer rate that is one step slower than a current transfer rate output from a selectable transfer rate-storing section. If the former is slower, a transfer rate-switching section switches to the transfer rate that is one step slower. A large decrease in the effective data transfer rate caused by data corruption is prevented.

Data transfer device, data transfer system, and data transfer method

An optical disc controller for an optical disc drive playing optically a first information storage medium and a second information storage medium having a higher storage density than the first medium. The controller includes: a rotation control section for controlling a rotating mechanism rotating the media; an equalizer for removing first frequency range components from an RF playback signal, obtained by irradiating each media with light and detecting reflected light, and amplifying second frequency range components; and a phase locking section for generating a sync clock signal to do synchronization detection with a digital playback signal obtained by digitizing the output of the equalizer. The rotation control section rotates the media while controlling the rotating mechanism such that RF playback signals are obtained at first and second transfer rates. The maximum playback frequency of the RF playback signal obtained from the first medium at the first transfer rate is substantially equal to that of the RF playback signal obtained from the second medium at the second transfer rate.

Optical disc controller and optical disc device having the same

An optical disc controller for controlling recording or reproduction of an optical disc includes: a rewritable memory for storing information necessary for recording or reproduction of the optical disc; a determination section for determining a class and type of the optical disc; a search section for searching for a region of the optical disc in which control information is recorded based on a determination result of the determination section; a reproduction section for reproducing the control information recorded in the region searched by the search section; and a memory control section for changing an arrangement of the memory based on at least one of the determination result and the control information reproduced by the reproduction section.

Growing community of inventors

Kyoto, Japan

Tatsuo Suzuki