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:
Jun. 06, 2000
Filed:
May. 30, 1997
Atsushi Tajiri, Osaka-fu, JP;
Kazushi Mori, Osaka-fu, JP;
Keiichi Yodoshi, Osaka-fu, JP;
Takao Yamaguchi, Osaka-fu, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
An optical pickup device of the present invention includes a substrate having at least a major surface, a semiconductor laser provided on the surface of the substrate for emitting laser beam, a reflection-type diffraction grating oriented to the semiconductor laser for splitting the laser beam into at least three beams and reflecting them upward, a hologram for receiving the three beams reflected from the reflection-type diffraction grating, and an objective lens for converging onto an optical recording medium the three beams transmitted by the hologram. The three beams reflected from the optical recording medium are focused by the hologram and directed onto the photodetector from the above.