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, 1993
Filed:
Dec. 22, 1989
Takahiro Nakayama, Ibaraki, JP;
Kenichi Onisawa, Ibaraki, JP;
Katsumi Tamura, Ibaraki, JP;
Kazuo Taguchi, Tokyo, JP;
Akira Sato, Ibaraki, JP;
Kenichi Hashimoto, Ibaraki, JP;
Yoshio Abe, Ibaraki, JP;
Masanobu Hanazono, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electroluminescent device including dielectric films each of which consists of first regions made of a material with a strong self-healing type dielectric breakdown characteristic, second regions made of a material with a strong propagating type dielectric breakdown characteristic, and mixed regions consisting of a mixture of these two materials, the first and second regions being arranged alternately in the film thickness direction with the mixed regions therebetween, the mixing ratio of these two materials in the mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, that is, the ratio of the other material increases. Thus, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction are continuous and periodic. These dielectric films, with a high breakdown field strength, make it possible to obtain an electroluminescent device having a large drive voltage margin and providing a luminescence of high brightness.