Hitachi, Ltd.

Hitachi-lg Data Storage, Inc.

Hitachi Consumer Electronics Co., Ltd.

Hitachi Media Electronics Co., Ltd.

Hideki Maruyama

Fumio Isshiki

Toshiteru Nakamura

Kenmei Masuda

Yukinobu Tanaka

Kenkichi Inada

Toshio Tsuchiya

Kuniaki Hirayama

Takeshi Ogata

Toshihiko Imachi

Yoshio Uemura

An optical disc apparatus records information onto plural disc shaped mediums of different standards or reproduces information from the plural disc shaped mediums. The optical disc apparatus includes an optical pickup equipped with a spherical aberration correcting unit using a movable lens, and a disc insertion unit for inserting and ejecting the disc shaped mediums. The spherical aberration correcting unit starts the movement of the movable lens to an initial position while the disc insertion unit inserts or ejects the disc shaped medium. As such, the present invention discloses the optical disc apparatus with a reduced disc recognition time for improving user convenience and a driving method thereof.

Optical disk apparatus and driving method thereof

An optical disk apparatus includes an optical pickup and a signal processor. The optical pickup includes an actuator for driving an objective lens, and a detected light intensity signal output part for outputting a detected light intensity signal to the processor. The signal processor includes a servo signal generator for generating a main push-pull signal and a sub push-pull signal on the basis of the detected light intensity signal supplied from the detected light intensity signal output part, a signal generator for generating a differential push-pull signal and a lens error signal by conducting addition/subtraction on the main push-pull signal and the sub push-pull signal, and a tracking offset correction signal generator which is input with the lens error signal to output a tracking offset correction signal. The differential push-pull signal correction is conducted by conducting addition/subtraction between the differential push-pull signal and the tracking offset correction signal.

Optical disk apparatus

An optical disc apparatus, for executing recording or reproducing on an optical disc having at least two recording/reproducing layers, includes an optical pickup, having a sphere aberration compensating portion, an objective lens, a driver portion, and an obtaining portion. The sphere aberration compensating portion sets up a compensation volume corresponding to an intermediate position laying between a deepest layer and a most front layer from the optical pickup, and the driver portion drives the objective lens in a direction approaching to the optical disc in accordance with the set compensation volume. When the sphere aberration compensating portion sets up the compensation volume corresponding to the deepest layer, and when the objective lens is driven in a direction approaching the optical disc, the driver portion drives the objective lens in a direction of separating from the optical disc.

Optical disc apparatus, driving method of optical disc apparatus

The present invention provides an optical disk apparatus and a focus jump method capable of reliably performing a focus jump by appropriately obtaining the amplitude of a signal such as a focus error signal in a multilayer optical disk. An optical disk includes jump areas which are provided separately from data areas and at which a focus jump is performed. When a focus jump is performed, an optical pickup is moved to the jump area, and the laser power level of the optical pickup is changed and set in accordance with a target layer to which the focus is jumped. A focus position is allowed to reach the target layer by counting the number of times of intersecting with recording layers using a reflected light from the optical disk while performing a focus sweep of an objective lens in the optical pickup.

Optical disk apparatus and focus jump method for multilayer optical disk

An optical disc drive apparatus which is mounted on a mobile apparatus, which at least reads information from a disc surface of an optical disc disposed in a predetermined position by using a pickup, which is robust against vibration, and which is capable of preventing collision between the disc surface of the optical disc and the pickup. The apparatus judges a road surface condition associated with location information on the basis of the location information concerning a location on a road on which the mobile apparatus is traveling, acquired externally and road surface condition information depending upon a road surface condition of a road on which the mobile apparatus travels. Servo characteristics of the optical drive apparatus are controlled according to control information associated with the judged road surface condition.

Optical disc drive apparatus and its control method

In an optical disk apparatus, an optical pickup includes an actuator for driving an object lens, and a sensed signal output part for making it possible to generate a tracking error signal and a lens error signal by addition/subtraction, and a signal processor includes a servo signal generator for generating a tracking error signal and a lens error signal on the basis of a signal supplied from the sensed signal output part, and a tracking offset correction quantity signal generator supplied with the lens error signal to output a tracking offset correction quantity signal. DC (direct current) offset correction is conducted by conducting addition/subtraction between the tracking error signal and both the lens error signal and the tracking offset correction quantity signal.

A highly reliable optical disk apparatus adapted to record and reproduce the information in and from plural types of optical disks is disclosed. An acquisition unit acquires a predetermined signal from the reflected light obtained by radiating a predetermined laser on each of the optical disks. A comparator compares the waveform of the signal acquired by the acquisition unit with the comparative waveform of the signal stored in a memory beforehand and obtained from the radiated laser corresponding to the optical disk. An identification unit identifies the type of the optical disk based on the result of comparison by the comparator.

Optical disk apparatus and disk identification method

For achieving an improvement on recording/reproducing quality of information, with enabling more adequate tilt adjustment, even for an optical disc to be used under a circumstance having a large temperature change, an optical disc apparatus for conducting recording or reproducing of video information onto/from the optical disc, through buffersand, while conducting a tilt adjustment through a learning of a tilt amount, comprises a temperature sensorfor detecting temperature within an optical pickup, wherein a control unit determines whether a relearning of the tilt amount of the optical pickup, upon basis of a change of temperature detected, a movement amount of the optical pickup between the time when a previous learning is done and the time when a present learning is done, and a remaining memory capacity of the buffers.

Optical disc apparatus

An arrangement is designed to achieve satisfactory tape contact by setting a specific ratio for the width of a drum window and the head length of a double azimuth head. The head length L is defined as the distance from the front end of the preceding head to the back end of the succeeding head. When the drum window width W is defined as the distance of the drum window in the rotary direction, the preceding head and the succeeding head are arranged within the drum window to satisfy the relation 1.15 L.ltoreq.W.ltoreq.1.28 L. When the space S1 is defined as the distance from the front end of the preceding head to the front end of the drum window, and the space S2 is defined as the distance from the back end of the succeeding head to the back end of the drum window, the preceding head and the succeeding head are arranged within the drum window to satisfy the relation 0.075 L.ltoreq.S1.ltoreq.0.14 L and 0.075 L.ltoreq.S2.ltoreq.0.14 L. According to this arrangement, the magnetic tape intrudes preferably into the space between the double azimuth head and the drum window. The magnetic tape envelopes and contacts the head surface, so that the tendency for a spacing to occur between the head and the tape is suppressed. The reproducing output is increased and stabilized in this way.

Growing community of inventors

Yokohama, Japan

Hideki Maruyama