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:
Jul. 21, 1992
Filed:
Jan. 09, 1990
C. Itoh & Co., Ltd., Osaka, JP;
Toshinori Morizani, Tokyo, JP;
Abstract
Herein disclosed is a method for manufacturing a base plate for a recording disc, which comprises steps of polishing the surface of the base plate of glass or aluminum, thereafter dispersing uniformly micro-crystals on the polished surface to form a portion where the micro-crystals are in contact with said polished surface, and subjecting the base plate to etching treatment with an etching agent in a gas phase or a liquid phase. Also disclosed is a base plate for a recording disc, which is obtained by uniformly dispersing micro-crystals on the surface of the base plate and subjecting the same to etching treatment, said base plate having very fine convexities and concavities on its surface.