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:
Jan. 26, 1982
Filed:
Apr. 11, 1980
Applicant:
Inventors:
Tatsuo Harada, Fuchu, JP;
Toshiaki Kita, Hinodemachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
3501 / ;
Abstract
A concave grating having grooves formed in a concave blank surface in which the grooves are so formed as to have a non-uniform, spacing in accordance with the following relationship: ##EQU1## wherein