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:
Dec. 03, 2002
Filed:
Feb. 08, 2001
Toshio Sakai, Sodegaura, JP;
Hisahiro Higashi, Sodegaura, JP;
Hiroaki Nakamura, Sodegaura, JP;
Hisayuki Kawamura, Sodegaura, JP;
Chishio Hosokawa, Sodegaura, JP;
Idemitsu Kosan Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a practical, organic, blue-emitting EL device having a long life and having high luminous efficiency and good thermal stability. The device comprises organic compound layers, of which at least one is an organic blue-emitting layer, as sandwiched between a pair of electrodes, and is characterized in that the organic blue-emitting layer comprises an organic host compound having a fluorescence quantum efficiency of not smaller than 0.3 in a solid state and a fluorescent substance, and the organic host compound and the fluorescent substance are selected such that the device retains a monomeric blue-emitting ability, and that all the organic compound layers have a glass transition temperature of not lower than 75° C., while the organic compound layers adjacent to the organic blue-emitting layer have a glass transition temperature of not lower than 105° C.