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:
Sep. 21, 1999
Filed:
Jun. 26, 1997
Applicant:
Inventors:
Hideo Maeda, Yokohama, JP;
Shigeru Ohuchida, Zama, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4423 ; 369112 ;
Abstract
An optical pick-up having a high-density double diffraction grating constructed with two high-density diffraction gratings superposed on each other wherein polarized light rays are separated so that P-polarized light rays pass through the double diffraction grating and S-polarized light rays are diffracted. The optical pick-up is disposed in the optical path between a light source and a recording medium.