US 6,324,137 B2Granted

Information recording and reproduction apparatus carrying out recording and reproduction of information using laser beam

AssigneeSanyo Electric Co., Ltd.

InventorsKenji Tanase, Atsushi Yamaguchi, Kenji Nakao, Hisashi Matsuyama, Yoshihiro Hori, Satoshi Sumi

Life of this patent

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Abstract

An information recording and reproduction apparatus for a magneto-optical medium includes a synchronizing signal generation circuit for generating a synchronizing signal to provide a pulsed laser beam at the time of reproduction according to an internal clock obtained from a reproduction signal. The laser beam is driven on/off according to the synchronizing signal at the time of reproduction to have the laser spot on the signal plane prevented from being enlarged, so that the reproducible domain is smaller than the domain of when a laser beam is continuously emitted. In reproduction, an optical superresolution method is applied simultaneous to provision of a pulsed laser beam to allow reproduction of higher density. An external synchronizing signal generation circuit for generating an external synchronizing signal according to a wobble on a surface of a recording medium can be used instead of a synchronizing signal generation circuit according to an internal clock.

Claims8

Dependent claims

An information recording and reproduction apparatus for an information recording medium, comprising:

optical means for emitting a laser beam on a plane of said information recording medium in which a signal is recorded, and detecting a laser beam reflected from said signal recording plane,
information reproduction means for reproducing information from the laser beam detected by said optical means,
drive means for driving said optical means so as to render said emitted laser beam into a pulsed laser beam, and
first synchronizing signal generation means for generating and providing to said drive means a first synchronizing signal for emitting said pulsed laser beam to said signal recording plane in reproduction, wherein said first synchronizing signal is generated in synchronization with a signal reproduced from said signal recording plane by said pulsed laser beam,
wherein said optical means blocks an inner portion of said laser beam emitted from said optical means so that a laser beam formed of a main lobe and side lobes is emitted on said signal recording plane only in reproduction.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/828,935Filed 10 Apr 2001 · division
Priority: JP 8-12987124 May 1996
Published: US 2001/0014065 A116 Aug 2001
Granted: 27 Nov 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

G11B 7/005
Recording, reproducing or erasing methods; Read, write or erase circuits therefor: reproducing
B82Y 10/00
Nanotechnology for information processing, storage or transmission
G11B 7/126
Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for…
G11B 7/1367
Separate or integrated refractive elements, e.g. wave plates: stepped phase plates