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:
Nov. 25, 2003
Filed:
Aug. 07, 2001
Sohmei Endoh, Miyagi, JP;
Manabu Satoh, Miyagi, JP;
Mitsuo Arima, Miyagi, JP;
Jun Shimizu, Miyagi, JP;
Etsuro Ikeda, Miyagi, JP;
Hirotaka Ozawa, Tokyo, JP;
Akitoshi Suzuki, Tokyo, JP;
Masayuki Takakuwa, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A recording medium and a recoding medium master, and a method of manufacturing the recording medium which comply with the standard of recording/reproducing characteristic established in the MD standard while enabling precise discrimination of the pit track and groove track and optical detection of the pits by optical pickup and the like are provided. Pits and grooves are arranged on a surface of a disc-shaped substrate so as to form a grooves and the ratio is from 1.00 exclusive to 1.13 inclusive. It is preferable that the track pitch of the grooves is from 1.50 &mgr;m inclusive to 1.70 &mgr;m exclusive. The width of the pits and grooves in the radial direction of the substrate is the same.