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:
Dec. 07, 1999
Filed:
Mar. 24, 1998
Nobuyuki Arakawa, Kanagawa, JP;
Masanobu Yamamoto, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc substrate having a reduced thickness and sufficient rigidity is provided which can be of a single-plate structure. It can be compatible with a magneto-optic recording and also with a conventional disc driving means. The substrate consists of a disc supporting portion (21) formed around the center of the substrate and of which one side (21a) provides a surface at which the disc is to be mounted on a disc driving means, and a recording portion (22) formed between the disc supporting portion (22) and a circumference of the substrate and of which one side (22a) provides a recording surface. The disc supporting portion (21) is designed thicker than the recording portion (22) so that the disc supporting surface (21a) and the recording surface (22a) will not lie together in a sample plane. A recess 25 may be formed between the recording portion (22) and disc supporting portion (21), and also a projection (27) may be formed along the circumference of the side (22b). Furthermore, one or more functional layer may be formed on the side (22b) opposite to the recording surface.