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:
Apr. 03, 2007

Filed:

Oct. 17, 2003
Applicants:

Akinori Ohkubo, Tsurugashima, JP;

Takuma Yanagisawa, Tsurugashima, JP;

Inventors:

Akinori Ohkubo, Tsurugashima, JP;

Takuma Yanagisawa, Tsurugashima, JP;

Assignee:

Pioneer Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/18 (2006.01);
U.S. Cl.
CPC ...
Abstract

A tilt angle detection device and method which generates, as a first push-pull signal, a difference between light reception signals corresponding to two light receiving surfaces of one side of a photodetector, which are divided along the track tangent direction; generates, as a second push-pull signal, a difference between the light reception signals corresponding to two light receiving surfaces of the other side of the photodetector; and generates a tilt signal that indicates a tilt angle defined by a normal on the recording surface of the optical recording medium at a position of irradiation of the laser beam and the optical axis of the laser beam in accordance to a difference between amplitudes of the first and second push-pull signals.


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