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. 28, 1992
Filed:
Mar. 13, 1991
Applicant:
Inventor:
Jae H Ryu, Seoul, KR;
Assignee:
Goldstar Co., Ltd., Seoul, KR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
313507 ; 313509 ;
Abstract
A thin-film EL display having a high-contrast ratio comprising a transparent ceramic substrate. A background electrode is formed on the lower surface of the ceramic substrate. A photochromism layer is formed on the upper surface of the ceramic substrate. The photochromism layer is black-colored when exposed to a required wavelength of light of 3,500 .ANG. to 5,100 .ANG.. Therefore, it is possible to avoid decrease in the contrast of the display device which may be caused by external light or light emitted from the fluorescent layer itself.