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:
Oct. 13, 1992

Filed:

Jan. 23, 1989
Applicant:
Inventors:

Akihiko Hashimoto, Hachioji, JP;

Hiroyuki Hagita, Hachioji, JP;

Koji Maruyama, Hachioji, JP;

Satoru Kato, Fukui, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 44320 ; 235456 ; 369 4435 ; 369 4442 ; 369116 ; 369118 ;
Abstract

An apparatus for reading information out of an optical record medium including a semiconductor laser diode for emitting a laser beam, a collimator lens, a beam splitter, an objective lens, converging lens and a photodetector. The laser beam emitted from the laser diode is made incident upon the optical record medium via the collimator lens, beam splitter and objective lens, and a light flux reflected by the optical record medium is made incident upon the photodetector via the objective lens, beam splitter and converging lens. The laser diode and collimator lens are arranged such that the laser beam is projected upon the optical record medium in a de-focused condition, while the objective lens is in-focused on the optical record medium.


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