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. 02, 1999
Filed:
Jul. 29, 1997
Applicant:
Inventor:
Fuyuki Habu, Yonezawa, JP;
Assignee:
Asahi Komag Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; B05D / ;
U.S. Cl.
CPC ...
360135 ; 427554 ;
Abstract
A substrate for a magnetic recording medium. The substrate is a non-magnetic brittle material having a substantially flat surface on which laser marks having a height in a range of 10-500 .ANG. are formed in a landing zone. The laser marks are formed by irradiating a pulsed laser beam having a wavelength capable of being absorbed in the non-magnetic brittle material within a range of substantially circular form having a waist diameter D .mu.m, and which has a physical property of 0.5<E.sup.v /(D/20).sup.2 <6 .mu.J where E.sup.v .mu.J represents a pulse energy for initiating vaporization of the glass substrate by irradiation of the pulsed laser.