Pioneer Corporation

Pioneer Electronic Corporation

Hideaki Yoshimura

Takashi Suzuki

Yoshihiro Hashizuka

Takao Shimamura

Kenichi Takahashi

Koichi Kikuchi

Shinya Honjou

Alex Bradshaw

Yoshimichi Nishio

Tomoko Miyagawa

Takashi Sasaki

Takeshi Sato

Kazunori Matsuo

Hitoshi Yamazaki

Kazuhiro Kiyoura

Koichiro Haraguchi

Takeshi Matsumoto

Yoshifumi Fujino

Mayumi Takahashi

Morio Nozaki

Kazuhiko Oogami

Nobutaka Kawakita

Yoshitaka Makino

Fumihiko Nakamura

There is provided a carrier mechanism which can move a carrier sectionto a desired position with high accuracy. The carrier mechanism is comprised of the carrier section, a driving motor, and an actuator formed of a cam mechanismfor transmitting a driving force of the driving motorto the carrier sectionto convey the same. When the carrier sectionis moved upward with respect to the present position, the carrier sectionis once moved (elevated) to a position in excess of a desired position, then moved downward from the exceeded position to the desired position. When the carrier sectionis moved downward from the present position, the carrier sectionis moved to the desired position without exceeding the desired position. By virtue of this operation, in both of the elevation and lowering of the carrier section, the carrier sectionreaches the desired section by lowering thereto at its final stage of the movement. Further, the so-called actuator for driving the carrier sectionis held in a predetermined direction, and therefore the carrier sectioncan be positioned to the desired position with high accuracy.

Carrier mechanism

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

An unbalanced waveform of a tracking error signal is automatically corrected within a short period of time. A peak value and a bottom value of a tracking error signal are obtained by a peak-hold circuit and a bottom-hold circuit, respectively. Based on the peak value and the bottom value, an amount of offset measured from a reference level and an amplitude of the tracking error signal are computed. An adjustment value is computed for correcting the unbalance between the peak value and the bottom value based on the amount of offset and the amplitude of the tracking error signal. The adjustment value is fed back to a tracking balance circuit so that the waveform of the unbalanced waveform of the tracking error signal is corrected.

Waveform controlling device for a tracking error signal

An optical information reproducing and/or recording system is provided with an optical system for irradiating a light beam to an information record surface of an information record medium and detecting the light beam reflected from the information record surface to output a light detection signal, an amplifying device for amplifying the light detection signal and generating a focus error signal which indicates an error of a focus point of the light beam with respect to the information record surface, and a feed back device for feeding back the focus error signal in the focus servo loop to change the focus point in accordance with a level of the focus error signal. An apparatus for controlling a bias amount of the focus error signal is provided with: a superimposing device for superimposing a disturbance signal to flutter the focus point with respect to the information record surface, onto the focus error signal; an error amount detecting device for detecting a focus error amount of the focus point, on the basis of the light detection signal outputted when the disturbance signal is superimposed; a parameter calculating device for calculating a gain parameter corresponding to an amplification factor of the amplifying device, and a sensitivity parameter corresponding to a detection sensitivity of the optical system; and a bias amount calculating device for calculating the bias amount.

Apparatus for controlling bias amount of focus error signal

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Kawagoe, Japan

Hideaki Yoshimura