Other

Pioneer Corporation

Kazuhiko Oogami

Masato Sakamoto

Mayumi Takahashi

Atsushi Kusaka

Norikazu Tada

Katsunori Tamamura

Akihito Fujiwara

Takeshi Sato

Kazunori Matsuo

Hitoshi Yamazaki

Yoshimichi Nishio

Hideaki Yoshimura

Yoshihiro Hashizuka

Morio Nozaki

Yoshitaka Makino

A focusing controller executes an appropriate focus jump even in a multilayer disk having layers of characteristics greatly different from each other. The focusing controller has an optical pickup including an objective lens for converging the light beam and a detector for receiving reflected light from the multilayer recording medium; an error signal generator for generating a focus error signal of the irradiated light beam from a detecting signal of the detector; an actuator for operating the objective lens; and a controller for controlling a focusing position of the light beam by operating the actuator based on the focus error signal. The controller calculates intensities of the reflected lights of two layers based on the detecting signal of the detector, and thus controls the timings of acceleration and deceleration signals of a focus jump between these two layers.

Focusing controller for focus jump control between recording layers of multilayer disk

A gain controlling apparatus includes a pre-amplifier for roughly adjusting a gain of a generation signal, which is generated on the basis of a reception signal from an optical disc; a variable amplifier for finely adjusting the gain on the basis of the roughly adjusted gain by the pre-amplifier; a memory for storing a plurality of values for adjusting the gain generated during a previous occasion of gain adjustment in time series; and a controlling device for controlling the pre-amplifier at a current occasion of gain adjustment on the basis of the respective stored values for adjusting the gain and controlling the variable amplifier, wherein the controlling device comprises a predicting device for predicting a current adjustment value, namely an adjusted value for the gain roughly adjusted at the current occasion by the pre-amplifier, and the controlling device controls the pre-amplifier on the basis of the predicted current adjustment value.

Gain controlling apparatus and method, information reproducing apparatus and method, and information recording apparatus and method

An apparatus for driving an optical pickup for a tracking servo control. The apparatus includes an emitting device disposed in the optical pickup for emitting a main beam to a first position on an information track of a recording medium and emitting at least two subsidiary beams to a second position and a third position on the information track of the recording medium, respectively. The positions of the main beam and the subsidiary beams are determined appropriately for a three beam method. The apparatus further includes: a tracking error signal generating device for generating a tracking error signal using returned light beams of the subsidiary beams from the recording medium; a driving device for moving the first position of the main beam and the second position and the third position of the subsidiary beams with respect to the recording medium; a tracking control device for outputting a driving signal based on the tracking error signal to the driving device; and a detecting device for detecting a damaged part on the recording medium. The tracking control device generates a pulse signal having a polarity opposite to a disturbance part of the driving signal generated due to at least one of the subsidiary beams passing on the damaged part, and uses this pulse signal as a part of the driving signal.

Drive apparatus for optical recording medium

Growing community of inventors

Kawagoe, Japan

Kazuhiko Oogami