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. 17, 2001
Filed:
Feb. 12, 1999
Taiyo Yuden Co., Ltd., Tokyo, JP;
Abstract
An optical disc having a transparent substrate, being recordable with a signal (s) by irradiating recording light at the side of the transparent substrate thereof, comprises a cover sheet being attached on the transparent substrate at a surface side for incidence of recording light and reproducing light, in detachable manner, wherein the stretching rate of the cover sheet is selected to be equal or less than 200%. Further, the thermal contraction rate of the cover sheet is selected to be equal or less than 1.5%, and the bonding force thereof onto a surface of the transparent substrate per 25 mm width to be from 10 g/25 mm width to 300 g/25 mm width. Thereby, the curve on the optical disc can be suppressed, if it is attached with the cover sheet of the surface of the transparent substrate thereof.