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:
Jul. 15, 1997
Filed:
Nov. 17, 1994
Takeshi Yamazaki, Hachioji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An optical pick-up apparatus for recording and/or reading information on and/or from an optical record medium including a semiconductor substrate, a semiconductor laser arranged on the semiconductor substrate, plurality of photodetectors formed in the surface of the semiconductor substrate, a diffraction gratings dividing a laser beam into main beam and two sub-beams, an objective lens projecting the main and sub-beams onto the record medium and directing these beams reflected by the record medium toward a hologram which diffracts each of the main and sub-beams into .+-.1-order beams which are received by the photodetectors. The apparatus is constructed to satisfy the following conditions: