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:
Apr. 06, 1999
Filed:
Oct. 31, 1996
Applicant:
Inventors:
Atsushi Mizutani, Anjo, JP;
Masayuki Katayama, Handa, JP;
Nobuei Ito, Chiryu, JP;
Tadashi Hattori, Okazaki, JP;
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; H05B / ; H05B / ;
U.S. Cl.
CPC ...
313506 ; 313502 ; 313503 ; 313506 ; 313507 ;
Abstract
A luminescent layer in an EL device composed of CaGa.sub.2 S.sub.4 :Ce includes a first luminescent layer and a second luminescent layer. The first luminescent layer has an atomic ratio of Ga to Ca being higher than that in the second luminescent layer, and directly disposed on a first insulating layer, whereby delamination can be prevented. The atomic ratio of Ga to Ca in the second luminescent layer is approximately equal to a stoichiometric ratio, so that the threshold voltage of the EL device can be kept low.