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:
Jun. 06, 2000

Filed:

Oct. 24, 1997
Applicant:
Inventor:

Takashi Tajiri, Saitama, JP;

Assignee:

Sony Corporation, Tokyo, JP;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 58 ; 369 54 ; 369 47 ;
Abstract

In accordance with the invention, an apparatus and method are provided in which it is possible to determine a type of disc which has been loaded before servoing is locked. A disc is rotated by a spindle motor, and a pickup is gradually moved toward the disc from a position spaced apart from the disc. A peak value of an obtained reflection is detected by a peak hold circuit is stored into a CPU. If the disc is a DVD (by way of example), a single layer DVD has a reflectivity higher than that of a double layer DVD. Accordingly, a single layer DVD and a double layer DVD can be discriminated from each other from the value of the peak reflection value obtained by the peak hold circuit.


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