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:
Jun. 22, 2010
Filed:
Oct. 22, 2002
Kazuo Ogino, Akishima, JP;
Koji Suzuki, Tokyo, JP;
Kazuo Ogino, Akishima, JP;
Koji Suzuki, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
Provided are a method for producing a glass suitable for an information recording medium required to have high qualities, a process for the production of a glass substrate blank from the above glass and a process for the production of a glass substrate from the above blank. The method is for the production of a glass containing an alkali metal element by melting a glass material in a glass melting apparatus and uses, as said melting apparatus, a melting apparatus whose glass-contact portion is made of a material containing zirconium and containing substantially no alkali metal element. In the process for the production of a glass substrate blank, the glass obtained by the above method is press-molded or is subjected to a float process, and in the process for the production of a glass substrate, the above glass substrate blank is lapped and polished.