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. 06, 1990
Filed:
Jun. 30, 1988
Wai-Hon Lee, Cupertino, CA (US);
Pencom International Corp., Sunnyvale, CA (US);
Abstract
The present invention is a combined surface emitting semiconductor laser and photodetector in a single housing with the photodetector positioned to detect light emitted from the surface emitting laser and reflected off of a medium. The surface emitting laser is mounted on the top surface of a chip which includes at least one set of two photodetectors for detecting a reflected beam. At least two photodetectors are used so that spacial variations in the reflected beam can be detected for focusing and tracking when the device is used in an optical head. Photodetectors are arranged to intersect a diffracted beam from a hologram lens used in an optical head. A rear emission photodetector for monitoring the power of the surface emitting laser is positioned so that it will not receive diffracted light which will interfere with its operation.