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:
Mar. 22, 1994
Filed:
Jun. 23, 1992
Applicant:
Inventors:
Akihiko Tomoda, Hamamatsu, JP;
Hisao Suzuki, Hamamatsu, JP;
Akira Kaneko, Hamamatsu, JP;
Hideki Tsuboi, Hamamatsu, JP;
Assignee:
Yamaha Corporation, Hamamatsu, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
548236 ; 548469 ; 548546 ; 548547 ; 549 60 ; 549252 ;
Abstract
In chemical structure of a fulgide type photochromic compound having the following general formula; ##STR1## introduction of electron donative groups into its heteroaromatic structure is effective in improving the long wave length sensitivity without any lowering in its thermal stability. Thanks to such combined functional properties, the products are advantageously used for optical recording media, copying media, printing media, optical filters and display materials.