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. 10, 2012
Filed:
Nov. 07, 2008
Takashi Matsubara, Shizuoka, JP;
Yoshitake Yanagisawa, Shizuoka, JP;
Takashi Matsubara, Shizuoka, JP;
Yoshitake Yanagisawa, Shizuoka, JP;
Sony Corporation, Tokyo, JP;
Abstract
In a process of manufacturing a disc master, a stamper, a disc substrate, and an optical disc, separation performance between the stamper and the disc substrate and maintenance of satisfactory signal characteristics after the optical disc is manufactured are taken into consideration in the step of manufacturing the disc master. In the disc master, a boundary portion between a recessed portion and a non-recessed portion includes a small protrusion which protrudes from a flat surface of the non-recessed portion. The shape of the disc master is inversely transferred to the stamper, and the shape of the stamper is inversely transferred to the disc substrate. The separation performance is improved and the signal characteristics are maintained due to the shape of the boundary portion.