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. 28, 1992
Filed:
Mar. 29, 1990
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04N / ;
U.S. Cl.
CPC ...
346108 ; 2503361 ; 7386141 ; 372 21 ; 372 69 ;
Abstract
An optical device for illuminating an object with a rectangular pattern having a uniform light intensity distribution includes n (n.gtoreq.1) polarization separating elements which a laser beam emitted from a laser source enters and each of which separates the laser beam into two beams in two directions. The angle of separation by the polarization separating element is set to be 2.sup.(n-1) times of the smallest one of the separation angles of the polarization separating elements used. At least one quarter-wave or half-wave plate is combined with the polarization separating elements. An imaging lens is provided for forming 2.sup.n beam spots on the object such as an optical laser disk plate.