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:
Mar. 18, 1997
Filed:
May. 04, 1994
Applicant:
Inventors:
Yoji Takeuchi, Toride, JP;
Toshio Oshima, Toride, JP;
Ryuzo Fukao, Ibaraki-ken, JP;
Hisao Kanzaki, Toride, JP;
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K / ; C09K / ; G06K / ; B32B / ;
U.S. Cl.
CPC ...
2523 / ; 250271 ; 428913 ; 428690 ; 235491 ;
Abstract
The invention provides a phosphor excited by infrared rays to emit infrared rays which has a nonacicular particle shape and a particle size of 4 .mu.m or smaller after being synthesized. The phosphor preferably comprises an oxoacid salt-containing compound including at least one element selected from the group consisting of Nd, Yb and Er. The invention further provides a material having a latent image pattern comprising said phosphor and an optical reading system which use the material having a latent image pattern.