Sony Corporation

Nobuyuki Asai

Satoshi Kato

Masaaki Ishihara

Nobuyoshi Kobayashi

Yuji Gendai

Junkichi Sugita

Shinobu Nakamura

Kazumasa Nishimoto

Tomohiro Ohama

An optical disk reproducing device includes: a signal reproducing section configured to read and decode information recorded on an optical disk by an optical pickup unit, and reproduce the information, wherein the signal reproducing section includes a gain controlled amplifier circuit configured to amplify an radio frequency signal generated from a light receiving element, an automatic gain control circuit configured to control a gain of the gain controlled amplifier circuit, and a signal processing section configured to derive a part of an automatic gain control value generated in the automatic gain control circuit, and generate a control signal for adjusting one of an optical system path and a detection system path for controlling the optical pickup unit.

Optical disk reproducing device and optical disk recording and reproducing device

A frequency control device capable of detecting a frame sync pattern and generating a frequency information accurately even if a reproduction signal is not zero-crossed, and an information reproduction apparatus having the same, which includes an oscillation circuit outputting a clock having a frequency corresponding to a control signal; a converter sampling an input analog signal having a predetermined pattern based on the clock and converting the same to a digital signal; and a frequency detection device detecting an object to be a sync pattern from a changing trend of the digital signal, generating a frequency information for controlling a reproduction clock based on the detected object to be the sync pattern, and outputting the same as the control signal to the oscillation circuit.

Frequency control device and information reproduction apparatus

A disc reproduction device, in which at the time of normal reproduction, a rotational speed of a spindle is detected based on a reproduction signal from the disc by a rotational speed counting circuit, a control signal that makes a speed error with respect to a reference speed zero is given to a first VCO as the control voltage thereof, a reproduction clock is generated while controlling the frequency and phase at a digital PLL circuit by using the oscillation output thereof as the reference frequency of the first PLL circuit containing a second VCO and in which, at the time of access, the control signal to the first VCO is switched to the output signal of the phase comparator by the switch circuit under the control of the controller and a multiple PLL circuit containing the first VCO, phase comparator, LPF, and so forth, is constituted to make the oscillation frequency of the first VCO track the reproduction speed at the destination of access predicted based on the access information by the controller. As a result, the access time can be reduced.

Disc player reproduction circuit with reproduction speed dependent VFO

Growing community of inventors

Kanagawa, Japan

Nobuyuki Asai