Hitachi, Ltd.

Hitachi-lg Data Storage, Inc.

Hiroshi Minoda

Kazuhiko Ono

Akio Fukushima

Shigeki Inoue

Eiji Ikeda

Hiroaki Shioyama

Akira Shimizu

Mikio Shiraishi

Hiroyuki Tanaka

Yasuo Otsuka

Takeshi Imai

Yasuyuki Kojima

Naohiro Ozawa

Toyota Honda

Masamichi Ito

Toshio Tanizoe

Akihiko Asada

The present invention provides an optical disk apparatus capable of stably performing a layer jump on an optical disk having plural recording layers and non-uniform interlayer distances. In an optical disk with at least three recording layers and non-uniform interlayer distances between respective recording layers, if a layer jump is carried out from a first recording layer to a second recording layer, a distance from the first recording layer to the second recording layer is obtained and driving voltages set according to the distance are applied to an actuator for the layer jump to carry out the layer jump. At this time, interlayer distances for combinations of the respective recording layers and applied driving voltages thereto are stored in a memory in advance and when necessary, corresponding driving voltages are read out from the memory and are set for the layer jump.

Optical disk apparatus, focus control method and optical disk

Provided is an optical disk device installed in a personal computer, including: an information creation unit that creates identification information for identifying the type of the personal computer based on a command transmitted from the personal computer; and a parameter selection unit that conducts switching, for parameter selection, concerning a parameter indicating an amount of unbalance of an optical disk, which has previously been determined depending on the type of the personal computer, in accordance with the identification information created by the information creation unit.

Optical disk device and parameter selection method

In an optical disk apparatus and a disk rotation speed control method thereof, enabling to rotate a disk at high speed, with stability and certainty, irrespective of mass eccentricity thereof, detection is made on the greatest value and the smallest value on the signal after conducting a process of a band pass filteron a lens error signal in a step response of a pickup, with using a wobble signal in the place of a tracking error signal and chaining an offset, when controlling the rotation speed of the apparatus by loading an optical disk therein, and thereafter, determination is made on whether the disk rotation speed be shifted to the high speed or not, upon basis of a value obtained through comparison of the maximum value (Max_spnup) and the minimum value (Min_spnup) obtained with the greatest value (Max_step) and said smallest value (Min_step) memorized, when shifting the disk rotation to the high speed.(Max&#x2212;Min)/(Max_step&#x2212;Min_step)

Optical disk apparatus and disk rotation speed control method thereof

A method and apparatus for reproducing data from an optical disc which has a plurality of recording layers reproducible from one side of the optical disc, and in which the disc is recorded in the OTP (Opposite Track Path) type. Upon receipt of a command of pausing, a pausing operation is performed by switching a moving direction of a focal point of an optical pickup in accordance with layer information of the recording layer to be currently reproduced.

Optical disc apparatus and method

An optical disc apparatus for recording information and/or reproducing on an optical disc which has at least two recording layers including layer and layer reproducible from one side of the disc. The apparatus includes an optical pickup having a laser source, an objective lens, and an actuator. A controller is provided which obtains a present layer information of a sector recording layer from light reflected from the disc, confirms a target layer information of a target recording layer, judges whether the present layer information is the same as the target layer information, and outputs a first control signal to the actuator when it is judged that the present layer information is layer and the target layer information is layer and outputs a second control signal to a slider.

Optical disk apparatus

A method for reproducing information on a dual layer disc which has two recording layers including layer and layer reproducible from one side of the &lsqb;disk&rsqb; disc, wherein each layer has a plurality of sectors. The method includes the steps of emanating an optical beam from a laser source, concentrating the optical beam on a recording layer with an objective lens, moving the objective lens in the direction of the thickness of the &lsqb;disk&rsqb; disc so that a focal point of the objective lens is focused on one layer of the two recording layers, obtaining a present layer information of a sector of the recording layer being reproduced from the reflected light from the &lsqb;disk&rsqb; disc, confirming a target layer information of a target recording layer of a target information, and moving the objective lens in a direction of the thickness of the &lsqb;disk&rsqb; disc until the focal point of the objective lens is focused on layer 1 when the present layer information is layer and the target layer information is layer

Optical disc apparatus accessing method and system therefor

There are provided a plurality of information recording surfaces to be reproduced on one side of an optical disc to be reproduced, and when accessing control of an optical pickup over a plurality of recording layers is performed, first, a beam focal point of the optical pickup is moved using a moving device to the recording layer on which target information is recorded to thereby perform switching processing of information recording layers during reproduction, after which accessing control of the optical pickup is performed using control processor similar to the access between the same recording layers, and with respect to the pausing operation, in a layer in which information is recorded from the inner circumference to the outer circumference, one track jumping is repeated toward the inner circumference, while in a layer in which information is recorded from the outer circumference to the inner circumference, one track jumping is repeated toward the outer circumference.

An optical disk apparatus for reproducing or recording and reproducing two or more sorts of optical disks whose recording plane heights are different is arranged to reproduce or record data from or on the optical disk transparently to the user and without the users intricate operations. For this purpose, the optical disk apparatus provides a disk discriminating circuit for discriminating the disks whose recording plane heights are different. The disk discriminating circuit operates to discriminate the disk before reproducing or recording the disk mounted to the optical disk apparatus and switch the optical system and the circuit system to the suitable ones to the discriminated disk and then reproduce or record the data from or on the disk.

Method and apparatus for automatically discriminating types of optical disks

There are provided a plurality of information recording surfaces to be reproduced on one side of an optical disc to be reproduced, and when accessing control of an optical pickup over a plurality of recording layers is performed, first, a beam focal point of the optical pickup is moved using a moving device to the recording layer on which target information is recorded to thereby perform switching processing of information recording layers during reproduction, after which accessing control of the optical pickup is performed using control processing circuit similar to the access between the same recording layers, and with respect to the pausing operation, in a layer in which information is recorded from the inner circumference to the outer circumference, one track jumping is repeated toward the inner circumference, while in a layer in which information is recorded from the outer circumference to the inner circumference, one track jumping is repeated toward the outer circumference.

There are provided a plurality of information recording surfaces to be reproduced on one side of an optical disc to be reproduced, and when accessing control of an optical pickup over a plurality of recording layers is performed, first, a beam focal point of the optical pickup is moved using a moving means to the recording layer on which target information is recorded to thereby perform switching processing of information recording layers during reproduction, after which accessing control of the optical pickup is performed using control processing means similar to the access between the same recording layers, and with respect to the pausing operation, in a layer in which information is recorded from the inner circumference to the outer circumference, one track jumping is repeated toward the inner circumference, while in a layer in which information is recorded from the outer circumference to the inner circumference, one track jumping is repeated toward the outer circumference.

An image copying system is disclosed which has a thermal head energized at a strobe current supply time rate corresponding to a current head temperature according to a preset strobe current supply time rate control characteristics. In copying operation at a standard speed, a read sensor 211 reads an image by performing N main scans in one sub scan. A signal processor 221 validates the image signal thus read once every N scans according to a selection signal from a mode control circuit 401. A record circuit 311 having a thermal head performs one main scan every sub scan. During a copying operation at a speed N times the standard speed, the sub scan speed is made N times and the read sensor 211 reads the image by performing one main scan every sub scan and the signal processor 221 makes the read image signal always valid by the selection signal. The record device 311 performs one main scan every sub scan. A single A/D converter is used for A/D converting head temperature as well as other output signal.

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Yokohama, Japan

Hiroshi Minoda