Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Ikuo Hidaka

Koji Oka

Toshiaki Ozeki

Yoshikazu Makabe

Kenji Koishi

Yuichi Kamioka

Naoyuki Nakamura

Yoshiyuki Miyabata

Daisuke Nomasaki

Kenichi Tatehara

Kiyoshi Nakamori

An A/D converter which converts an analog input signal into a digital output signal by performing time-divisional parallel processings on the analog input signal using first and second pipeline type unit A/D converters. The A/D converter sets plural unit A/D converters performing parallel processings according to a system request, such that, when the A/D converter operates with a conversion frequency that is lower than the maximum conversion frequency, the unit A/D converter is halted by a control signal, thereby reducing inter-channel errors among the unit A/D converters to improve the precision of the A/D converter.

A/D converter and A/D conversion method

A first Delayed Flip Flop includes a first D input terminal, a first clock input terminal, a first output terminal outputting a signal inputted to the first D input terminal based on the clock signal, and a first inversion output terminal inverting and outputting the signal inputted to the first D input terminal and outputting the signal to the first D input terminal as a feedback. A second Delayed Flip Flop includes a second D input terminal receiving the output from the first output terminal of the first Delayed Flip Flop, a second clock input terminal, and a second output terminal outputting the signal inputted to the second D input terminal as a first output based on the clock signal. A third Delayed Flip Flop includes a third D input terminal receiving the output from the first inversion output terminal of the first Delayed Flip Flop, a third clock input terminal, and a third output terminal outputting the signal inputted to the third D input terminal as a second output based on the clock signal. The first output and the second output have signal waveforms inverted at the same timing.

Clock signal generating device and analog-digital conversion device

In an optical disc apparatus, a semiconductor SLD driving device is mounted on an optical pickup in order to realize a high speed switching of drive current for a semiconductor laser diode (SLD), necessary for recording data. The SLD is placed. within 5 cm from the SLD driving device. The driving device becomes a heat source due to driving current of the SLD, and increases a temperature of the optical pickup. Since the temperature rises proportionally to power consumption, power saving is required. A voltage supplied to the driving device is controlled to be a minimum level necessary for keeping the driving device still working on basic functions. The SLD driving device is mounted to the optical pickup, and this driving device handles N pieces of input signals for setting semiconductor laser power and N pieces of switch-timing-input-signals for selecting respective input signals. A supplied voltage is controlled so that a voltage supplied to the output section of the driving device is a minimum value necessary for keeping the output section still operating. A power source is placed outside of the pickup.

Semiconductor laser diode driving device and driving method

Growing community of inventors

Kyoto, Japan

Ikuo Hidaka