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:
May. 08, 1990
Filed:
Oct. 12, 1988
Applicant:
Inventors:
Kazuyoshi Shigematsu, Chiba, JP;
Shigenori Shirouzu, Chiba, JP;
Shuji Sakamoto, Chiba, JP;
Toshiyasu Suzuki, Chiba, JP;
Assignee:
Idemitsu Kosan Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528196 ; 528204 ;
Abstract
A resin material for optical instruments comprising a polycarbonate having the repeating units represented by the following general formula: ##STR1## wherein X represents ##STR2## has an extremely small birefringence particularly to oblique-incident lights.