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:
Sep. 02, 2003
Filed:
Apr. 19, 2000
Masato Nishida, Tokyo, JP;
Tetsuhiro Sakamoto, Chiba, JP;
Toshiyuki Kashiwagi, Tokyo, JP;
Motohiro Furuki, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc and its manufacturing method in which humps may be prohibited from being formed on an outer rim area of the disc to assure optimum surface properties of a light transmitting layer of the disc to contribute to further increase in recording capacity. On a substrate of an optical disc are sequentially formed a recording portion and a light transmitting layer . The light falls on the light transmitting layer to record and/or reproduce information signals for a signal recording area of the substrate . The radial distance D from the outermost rim of the substrate to the signal recording area is selected to be larger than the radial width L of a hump formed on the outer rim of the light transmitting layer . The hump has a height h from the surface of the light transmitting layer not larger than 70 &mgr;m.