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. 14, 1995
Filed:
Dec. 21, 1992
Hiroyuki Imataki, Kawasaki, JP;
Tetsuya Satoh, Kawasaki, JP;
Mizuho Hiraoka, Kawasaki, JP;
Tomoyuki Tamura, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method produces a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; the projection having different etching velocities along its projected thickness; and defining a pair of convergent opposite inclining side slopes. Each slope of the pair forms an acute inclining angle with respect to extension of the mold surface. A pattern-forming layer is formed comprising a common metal element throughout its thickness and an additional element differing in composition from the common metal element in the thickness direction of the pattern-forming layer. The common metal element and the additional elements have different etching velocities in the thickness direction of the pattern-forming layer. The pattern-forming layer is selectively etched with a common etchant to form the projection.