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:
Jul. 31, 2001
Filed:
Aug. 23, 1999
Hirofumi Takemura, Kamakura, JP;
Satoshi Sugano, Yokohama, JP;
Hiroyasu Yashima, Shizuoka-ken, JP;
Yohe Shimizu, Shizuoka-ken, JP;
Tsuyoshi Oyaizu, Fukaya, JP;
Akira Mikami, Kumagaya, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A red emitting phosphor comprises a yttrium oxysulfide phosphor as a base material. A red emitting phosphor of medium particle size type has such a particle size distribution that a content of a component of a particle diameter of less than 4.0 &mgr;m is 15% or less, that of a component of a particle diameter of 4.0 &mgr;m or more and less than 8.0 &mgr;m is 75% or more, and that of a component of a particle diameter of 8.0 &mgr;m or more is 10% or less. A red emitting phosphor of larger particle size type has such a particle size distribution that the content of a component of a particle diameter of less than 5.04 &mgr;m is 20% or less, that of a component of a particle diameter of 5.04 &mgr;m or more and less than 10.079 &mgr;m is 70% or more, and that of a component of a particle diameter of 10.079 &mgr;m or more is 10% or less. Phosphor layers employing these red emitting phosphors are excellent in denseness. Accordingly, a cathode ray tube of high contrast and high quality can be provided.