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. 26, 1993
Filed:
Jun. 12, 1991
Applicant:
Inventors:
Yoshio Yoshida, Tenri, JP;
Takahiro Miyake, Tenri, JP;
Yasuo Nakata, Kashihara, JP;
Yukio Kurata, Tenri, JP;
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ; G11B / ;
U.S. Cl.
CPC ...
359485 ; 359558 ; 359569 ; 369109 ; 369110 ; 2502 / ;
Abstract
A polarization diffraction element comprising two diffraction gratings formed on both faces of a substrate respectively. Both the diffraction gratings have grating lines which are arranged at the same grating pitch, and whose directions mutually form a predetermined minute angle. The grating lines may also be arranged parallel to each other. In this case, the relationship between grating pitches D.sub.1, D.sub.2 of the respective diffraction gratings and the wavelength .lambda. of an incident light is expressed as: