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:
Sep. 11, 1990

Filed:

Jun. 20, 1988
Applicant:
Inventors:

Masatomo Seya, Hyogo, JP;

Kazuo Okada, Hyogo, JP;

Motomu Yoshimura, Hyogo, JP;

Mitsuo Maeda, Hyogo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
365119 ; 365106 ; 365215 ; 369106 ; 372 32 ;
Abstract

A wavelength selective optical recording and reproducing device has a reference wavelength in a marker hole of a medium. The optical detector is adapted to detect light which is reflected from or transmitted through the marker hole. A phase detector detects the phase of an output of the optical detector by using a high frequency signal as a reference to obtain a signal indicative of the deviation of the wavelength of the output from a desired wavelength. A wavelength regulator is responsive to the wavelength deviation to control the wavelength of the light source to be the desired wavelength.


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