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:
Feb. 17, 2009
Filed:
Mar. 29, 2005
Keisuke Ohta, Higashihiroshima, JP;
Takeshi Kanai, Higashihiroshima, JP;
Keisuke Ohta, Higashihiroshima, JP;
Takeshi Kanai, Higashihiroshima, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical pickup device according to the present invention is constituted so that a laser beam emitted from a light receiving and emitting integral-type element is transmitted or reflected by a beam splitter, transformed to a parallel beam by a collimator lens, introduced into an objective lens, transmitted through the objective lens, and collected on a recording surface of an optical disc and the laser beam thus collected is returned to the light receiving and emitting integral-type element via a reverse path after the laser beam is reflected by the recording surface of the optical disc. The optical pickup device includes a front monitor light receiving element that is arranged between the light receiving and emitting integral-type element and the collimator lens, receives a part of the laser beam emitted from the light receiving and emitting element, and detects a quantity of the received laser beam. The front monitor light receiving element includes a received-light-quantity increasing unit that increases the quantity of the received laser beam.