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. 09, 1999
Filed:
Oct. 17, 1994
Applicant:
Inventor:
Tatsunori Ide, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
3692754 ;
Abstract
In an optical data recording media provided with a recording layer which changes its optical characteristics by the difference of heat history of heating and cooling by the irradiation of the laser light to a transparent substrate on which tracking channels have been formed. The width of an extruded or concave region formed by the tracking channels on the substrate is narrower than the diameter of the laser beam being used for recording, erasing and reading. Thereby, a problem which is associated with the recording frequency-dependent erasing efficiency in a case where the pulse width modulation method is used as the modulation method, can be solved.