Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Yasuo Nishihara

Tetsuo Saimi

Masatoshi Yajima

Hiroyuki Yamaguchi

Yasuhiro Tanaka

Kenji Nagashima

Yoshihiro Mushika

Kazumasa Takata

Shinichi Yamada

Masanari Mohri

Koji Funami

Kenji Takauchi

Seiji Kumazawa

Yoshiro Kitamura

Masaya Kuwahara

Masuo Maruyama

Masayoshi Shioya

Akihiro Sakaguchi

Yoichi Saito

A method for manufacturing an optical unit () having an optical element () and a support member () supporting the optical element. According to the method, at least one of the optical element () and the support member () is deformed, securing the optical element () and the support member () together.

Optical unit and its manufacturing method

Optical disks compliant with different standards are recorded or reproduced by a single recording/reproducing apparatus by a first step of determining a substrate thickness of the disk based on a focusing error signal, when a focusing section for bringing the light beam into a focus on the disk is moved in such a way as to approach or withdraw from the recording surface of the disk; a second step of performing any one step of determining the number of recording surfaces of the disk when the focusing section is moved in such a way as to approach or withdraw from the recording surface of the disk, and determining whether or not the disk can be recorded and reproduced using a tracking error signal detected when the light beam crosses the track.

Disk type determination method

The disk device of this invention includes: a disk driving section for rotating a disk; a head for recording and/or reproducing information on and/or from the disk; a head moving section for moving the head from a start position to a destination position; a temperature calculation section for calculating a temperature change at a predetermined position, wherein the calculation is carried out based on the information of the start position and the destination position; and a control section for controlling the disk driving section and/or the head moving section depending on the temperature change calculated by the temperature calculation section.

Disk device with temperature calculation section for calculating temperature change and difference

In an optical head, two object lenses,fixed to a lens holder,are provided to serve as means for condensing a light beam,wherein these object lenses,are at positions eccentric from a support axis,The object lenses,and,are fabricated to satisfy prescribed conditions to suppress aberration. When either object lens,or,is selected for an optical recording medium,degrading of signals can be prevented. Alternatively, two light sources,are provided for one object lens,, and the object lens is fabricated to satisfy prescribed conditions to suppress aberration. When either one of the light sources is used, degrading of signals can be prevented. In a different optical head, a recording medium,is set on a disk driving device,and an optical head,is provided movable freely in radial directions. The tilt of the recording medium is detected with a sensor, and the optical axis of the beam is controlled according to the detected tilt to cancel aberration.

Optical head

To present an objective actuator small in the number of parts, easy in soldering and assembling, heightened in the motion precision and brake effect, free from undesired resonance due to torsional motion of the objective lens holding member, heightened in the secondary resonance frequency by the torsional motion of the objective lens holding member, and suppressed of its amplitude. A lens holding member holding an objective lens and a housing are simultaneously and integrally molded through four linear spring members inserted in a die. Afterwards, a pair of magnets are fixed on the lens holding member, and an electromagnetic coil is wound, and wire terminals are wound in the wire arrangement grooves, then a soldered coil frame is fixed on the housing. A brake member is injected into the recess space enclosing linear spring members with the inside of the side wall of the housing and the inner wall, the brake frame, its partition wall, and part of the coil frame, from the side surfaces. The objective lens is mounted on the middle and top of the lens holding member holding the objective lens, and an optical plate is fixed in the middle of the lower surface, thereby forming a rigid nearly hexahedral structure, in which the suspension center by the linear spring members and the driving center by the driving system of the electromagnetic coil and magnets are matched, and the moment balance of the lens holding member including the objective lens and optical plate is achieved on this driving center.

Objective lens actuator

Optical-beam 2 emitted from semiconductor laser device 1 is transformed into parallel-light 4 by means of collimator lens 3, and a part of parallel-light 4 passed through parallel glass-plate 7 of which the front-surface is mirror finished and the rear-surface is frost finished is inputted into detector 5 monitoring the light-quantity. The optical-beam reflected from parallel glass-plate 7 is focused on information medium 9 after it passed through a collimator-lens 6. The optical-beam reflected from information medium 9 is then introduced on a detector disposed on the semiconductor laser device taking an reversed course. Since no interference of light transmitted through detector 5 is generated in this optical head, a higher linearity of the output of detector 5 can be obtained so that the better stabilized output control of semiconductor laser device 1 by means of laser control circuit 11 can be obtained.

Optical head with a translucent plate to split a light beam

Growing community of inventors

Osaka, Japan

Yasuo Nishihara