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:
Feb. 04, 1992
Filed:
Jul. 09, 1990
Seiichi Matsushima, Tsukuba, JP;
Masahide Yagi, Toride, JP;
Masahiro Suzuki, Ibaraki, JP;
Yasuyuki Mori, Ibaraki, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
Disclosed is an optical data recording medium provided with a glass substrate and a recording layer carried by the glass substrate, wherein the glass substrate is composed of a glass plate having a mixed layer of metallic tin or a tin compound formed on at least one surface thereof, a content of the metallic tin or tin compound on the surface of the glass substrate being regulated to 1.3 wt % or less and the entire surface of the glass plate being subject to a chemically reinforcing treatment, and also disclosed is a method of manufacturing an optical data recording medium provided with a glass substrate and a recording layer carried by the glass substrate, which comprises the steps of making a glass plate by a float method using melted metallic tin for the glass substrate, cutting the glass plate to a desired configuration and size, polishing at least one surface of the glass plate which is in contact with the melted metallic tin when making the glass plate to regulate a content of tin in the polished surface to 1.3 wt % or less, and subjecting the polished glass plate to a chemically reinforcing treatment.