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:
May. 26, 1998
Filed:
May. 17, 1994
Nobuhiro Umebayashi, Tsukuba, JP;
Hiroshi Obara, Toride, JP;
Hiroshi Ishihama, Shimotsuma, JP;
Yoshitaka Kojima, Hitachi, JP;
Shoichi Nakashima, Hitachi, JP;
Shizuka Yamaguchi, Katsuta, JP;
Hitaci Maxell, Ltd., Osaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
There is provided a stamper for producing a recording medium exhibiting excellent durability and capable of stably forming projections and pits and a method of producing the stamper. A stamper for producing a recording medium comprising projections and pits in a predetermined pattern on the surface thereof, wherein a value of tan .theta..sup.-1 obtainable from an enlargement angle .theta. of an output from a cartridge with respect to an enlargement of an output denoting a load measured by a test of scratching the surface having the projections and pits under conditions that a diameter of a stylus is 100 .mu.m and a loading speed of 1 .mu.m/second is 1.3 or more.