Patents Assigned to Hitaci Maxell, Ltd.
  • Patent number: 5756130
    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.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: May 26, 1998
    Assignees: Hitaci Maxell, Ltd., Hitachi, Ltd.
    Inventors: Nobuhiro Umebayashi, Hiroshi Obara, Hiroshi Ishihama, Yoshitaka Kojima, Shoichi Nakashima, Shizuka Yamaguchi