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:
Sep. 04, 2001
Filed:
Nov. 12, 1999
Susumu Uehara, Sagamihara, JP;
Yasuo Ochi, Kunitachi, JP;
Kabushiki Kaisha Ohara, Sagamihara, JP;
Abstract
There is provided a long-lasting phosphor having a base crystal of {dot over (a)}kermanite crystal structure consisting of R′ (where R′ is one or more elements selected from the group consisting of Ca, Sr and Ba), Mg, Si, O and N and comprising Eu as an activator and one or more co-activators such as Dy. The long-lasting phosphor is produced by sintering materials including strontium nitrate to grow the base crystal of {dot over (a)}kermanite crystal structure, or by changing a solution containing constituent elements or material in the state of suspension into fine particles of liquid by atomization and thereafter heating the fine particles of liquid in a gas stream under oxidating, neutral or reducing atmosphere. The new Mohs' scale of hardness of the long-lasting phosphor is less than 1. Phosphorescence brightness of the long-lasting phosphor 2 minutes after stoppage of irradiation of illuminance of 1000 lux for 30 minutes with a white fluorescent lamp is 200 mCd/m,or over.