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. 24, 2002
Filed:
May. 01, 2001
Applicant:
Inventors:
Hiroaki Takahata, Tokyo, JP;
Hisaji Oyake, Tokyo, JP;
Assignee:
TDK Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 3/70 ;
U.S. Cl.
CPC ...
G11B 3/70 ;
Abstract
In an optical recording medium comprising a substrate including parallel extending lands and grooves on one surface thereof, the grooves serving as recording tracks, and the lands being formed with prepits, the height H of the land disposed between the prepit and the groove divided by the height H of the land in a prepit-free region, both as measured from the groove bottom, i.e., H /H ranges from 0.25 to less than 1. This enables to significantly increase the recording density of the medium without a substantial cost increase.