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:
Nov. 18, 2014
Filed:
Oct. 11, 2012
Hironori Nakahara, Tokyo, JP;
Toshiya Matozaki, Tokyo, JP;
Nobuo Takeshita, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An optical component, a hologram, and a photodetector are configured in an optical head device of an optical disc device such that a +1-order beam or a −1-order beam of diffracted light generated from light reflected from an information track in the intended information recording layer strikes the interior of the light-receiving surfaces of the tracking error detection light-receiving sections, a +1-order beam or a −1-order beam of diffracted light generated from light reflected from an information track in an information recording layer one layer deeper than the intended information recording layer strikes outside the light-receiving sections, and a +1-order beam or a −1-order beam of diffracted light that is generated from light reflected from an information track in an information recording layer one layer shallower than the intended information recording layer strikes outside the light-receiving sections.