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:
Nov. 01, 1994
Filed:
Apr. 23, 1993
Applicant:
Inventors:
Junichi Hibino, Hirakata, JP;
Eiji Ando, Katano, JP;
Assignee:
Matsushita Electric Industrial Co. Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430345 ; 430 19 ; 430495 ; 430962 ; 430945 ; 252586 ;
Abstract
The present invention provides a photochromic material which comprises a spiropyran compound of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are independently alkyl groups each containing 1 to 30 carbon atoms and Y is a halogen. The photochromic material possesses absorption sensitivity at wavelengths in the length region of about 700 nm which is the oscillation range of a semi-conductor laser device, and possesses higher stability compared with conventional one when it becomes a colored form.