Pioneer Corporation

Yoshihiro Hashizuka

Takashi Suzuki

Kenichi Takahashi

Hideaki Yoshimura

Takao Shimamura

Koichi Kikuchi

Shinya Honjou

Kazunori Matsuo

Hitoshi Yamazaki

Yoshimichi Nishio

Takashi Sasaki

Takeshi Sato

Hideaki Watarihana

Hiroki Goto

Morio Nozaki

Kazuhiko Oogami

Yoshitaka Makino

An optical disk playing apparatus which performs at least a focusing servo operation for reading light as a servo operation and irradiates the reading light onto one optical disk, receives reflected light from the optical disk by a pickup to obtains a light receiving signal, moves an irradiated position of the reading light onto the optical disk to cross tracks on the disk; generates a tracking error signal in response to the reading signal during the track crossing; compares the tracking error signal with a threshold value; and determines the type of the optical disk in accordance with the number of pulses in the compared result signal within a predetermined period from start of the track crossing.

Optical disk playing apparatus and method for discriminating optical disk

A method for reproducing information recorded on a disc is provided. In the method, a reproduction signal is irradiated towards the disc to produce a corresponding read signal. Also, the reproduction signal is positioned at a first position within a non-program area of the disc and is attempted to be focused on the disc. If the reproduction signal is focused on the disc, the method determines if the read signal has a valid signal level. If the read signal does not have the valid signal level when the reproduction signal is positioned at the first position, the reproduction signal is moved to a second position within a program area of the disc while the reproduction signal remains focused on the disc. Then, the method determines if the read signal has the valid signal level when the reproduction signal is positioned at the second position. Also, a disc player that employs the method and a software program that instruct a controller to perform operations in accordance with the method are also provided.

Disc player capable of reproducing a partially recorded disc

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 servo control apparatus of an optical pickup is provided for reading recorded information from a recording medium and generates a read signal. The apparatus includes an error signal extracting part for extracting an error signal which indicates a deviation amount of a reading position from a target reading position of the optical pickup; a drive part for driving the optical pickup to change the reading position; an equalizer for equalizing the error signal and supplying a drive signal which indicates a driving amount of the drive part; a detecting part for detecting a dropout portion in the read signal; an identifying part for identifying a form of the dropout portion detected in the detecting part; and a controller. The controller performs control to change a gain of the equalizer in accordance with the identified form of the dropout portion.

Apparatus for detecting dropout, an error signal extracting unit, and unit for identifying type of dropout in an optical pickup

A servo adjustment apparatus for setting an adjustment value for servo control of at least one of optical recording of information on information recording surfaces and optical reproduction of information recorded on the information recording surfaces, is provided. A setting device sets an adjustment value corresponding to one of the information recording surfaces. Another setting device sets another adjustment value corresponding to another one of the surfaces other than the one of information recording surfaces. Then a calculation device calculates a relational value indicating a relationship between the adjustment value and another adjustment value. A storage device stores calculated relational value. A resetting device resets the adjustment value using another adjustment value set previously and the relational value when the adjustment value is reset, and resets another adjustment value using the adjustment value set previously and the relational value when another adjustment value is reset.

Method of and apparatus for setting servo adjustment value, reproducing information and recording information under servo control using servo adjustment value

A servo-control apparatus is provided for use with an optical disc player for reading and/or recording information. The apparatus includes an adjustment section for performing coarse and fine adjustment of a servo loop gain in accordance with a storage medium loaded in the player; a memory for storing a gain adjustment value; a discriminator for determining, upon one of reading and recording information, that the storage medium has already been subjected to the coarse and fine adjustment; and a controller. The controller allows the adjustment section to perform the fine adjustment of the servo loop gain in accordance with the stored adjustment value when it is determined that the storage medium has already been subjected to the coarse and fine adjustment.

Servo control apparatus for optical disc player

A disc player can be used in common for discs having different focus positions of an object lens with respect to a recording surface. The disc player carries out focus servo control with respect to the discs and reads out recorded information. The disc player comprises a judging device, a waveform setting device and a focus searching device. The judging device judges a type of disc set at the disc player. The waveform setting device selectively sets a predetermined waveform information in accordance with results of judgement by the judging device, from a plurality of waveform information which are held in advance for use in focus searching for the types of discs. The focus searching device generates a focus search signal based on the waveform information set by the waveform setting device, and carries out focus searching, at a time of start-up of the disc player, before the focus servo control is carried out.

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Kawagoe, Japan

Yoshihiro Hashizuka