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:
Oct. 20, 2009
Filed:
Jun. 22, 2005
Nobumasa Ono, Hashimoto, JP;
Nobumasa Ono, Hashimoto, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A light receiving and emitting integrated device is provided that can be connected to an IC for an optical pickup of the discrete package type, regardless of use of the knife edge method for a focus servo signal. In the light receiving and emitting integrated device, a diffraction grating branches light emitted from a semiconductor laser into three, namely, first to third lights, a hologram element divided into four regions, namely, first to four regions divides the first to third lights reflected by an optical recording medium, and four light receiving segments provided in a light receiving element receive and detect the first light. A focus servo signal can be obtained by the knife edge method using detection outputs of the first light received and detected by the four light receiving segments.