The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Mar. 21, 1995

Filed:

Aug. 17, 1993
Applicant:
Inventors:

Takumi Sugaya, Hachioji, JP;

Takao Rokutan, Higashimurayama, JP;

Mitsuo Oshiba, Hachioji, JP;

Takefumi Sakurada, Akishima, JP;

Naoaki Tani, Hachioji, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 15 ; 369 4437 ; 369 4438 ;
Abstract

According to the optical information recording/reproducing device of the present invention, upon recording of information, when a pit image on an optical detector which is formed by a recording optical beam spot at an information recording time arrives at a position of a O-order diffraction light spot image, while an optical card is moving in the forward direction, a light receiving element for signal reproducing senses a change in light amount. A verify signal is obtained immediately after recording based on the light amount change to perform a verify operation. Further, when a pit image on the optical detector formed by the recording optical spot arrives at a position of the image of the primary diffraction optical spot while a moving direction of the optical card is reversed and the optical card moves in the reverse direction to perform recording, a signal reproducing light receiving element senses a change in light amount. A verify signal is obtained immediately after recording based on the light amount change to perform a verify operation. Since irradiation is made in which the space between the recording optical spot and the O-order diffraction light spot is made equal to the space between the recording optical spot and the primary diffraction light spot b, an optical detector can receive the verify signal at the same timing even if the optical card moves in the forward or reverse direction.


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