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.
Patent No.:
Date of Patent:
Mar. 23, 1999
Filed:
Feb. 04, 1998
Kouichi Takamine, Hirakata, JP;
Yasuaki Edahiro, Habikino, JP;
Hiromichi Ishibashi, Ibaraki, JP;
Mitsurou Moriya, Ikoma, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
The tilt control apparatus of the invention controls to minimize an error in an orthogonal relationship between an optical disk and an optical axis of a light beam irradiated onto the optical disk. The tilt control apparatus includes: an optical pickup for irradiating the light beam onto the optical disk, thereby reproducing information recorded on the optical disk; an orthogonality error detector for outputting an orthogonality error signal corresponding to the error in the orthogonal relationship between the optical disk and the optical axis; a tilting mechanism for tilting the optical axis; a tilt controller for controlling such that the optical disk falls at right angles with the optical axis by driving the tilting mechanism in response to the orthogonality error signal; a pulse width variation detector for outputting a pulse width variation signal corresponding to a variation in a pulse width of an information reproduced signal obtained from the optical pickup; and a target value variable circuit for varying a control target value of the tilt controller based on the pulse width variation signal.