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. 20, 2007
Filed:
Aug. 04, 2003
Toshiharu Mori, Settsu, JP;
Hideki Kawai, Nishinomiya, JP;
Toshiharu Mori, Settsu, JP;
Hideki Kawai, Nishinomiya, JP;
Minolta Co., Ltd., Osaka, JP;
Abstract
A glass substrate for use as the substrate of an information recording medium such as a magnetic disk, magneto-optical disk, DVD, or MD or of an optical communication device, and a glass composition for making such a glass substrate, contains the following glass ingredients: 45 to 75% by weight of SiO; 1 to 20% by weight of AlO; 0 to 8% by weight, zero inclusive, of BO; SiO+AlO+BOaccounting for 60 to 90% by weight; a total of 0 to 20% by weight, zero inclusive, of RO compounds, where R=Li, Na, and K; and a total of 0 to 15% by weight, zero inclusive, of TiO+ZrO+LnO, where LnOrepresents at least one compound selected from the group consisting of lanthanoid metal oxides, YO, NbO, and TaO.