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:
Aug. 24, 1999
Filed:
Apr. 25, 1997
Applicant:
Inventors:
Tatsuya Senoo, Sagamihara, JP;
Hisao Yatsuda, Sagamihara, JP;
Assignee:
Kabushiki Kaisya Ohara, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C / ; C03C / ; C03C / ; C03G / ;
U.S. Cl.
CPC ...
257650 ; 257794 ; 257704 ;
Abstract
A low alpha-ray level glass which emits only an extremely small amount of alpha-ray while maintaining excellent chemical durability, coefficient of thermal expansion and hardness is obtained by introducing fluorine into a SiO.sub.2 --B.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --R.sub.2 O (R being an alkali metal) system glass of a specific content range. The amount of alpha-ray emitted from this glass is below 0.02 count/cm.sup.2.hr.