Patents Assigned to Hoya Electronics Corporation
  • Patent number: 5316844
    Abstract: A magnetic recording medium for contact recording has a layered structure sequentially with a substrate made of an aluminum alloy having a maximum surface roughness R.sub.max between 100 .ANG. and 300 .ANG. and having no surface protrusions or unevenness higher than 760 .ANG., a magnetic layer formed thereon by sputtering through underlying layers of Tiw film and Cr film, a non-magnetic first protective film formed by sputtering, a second protective film having hard particulates with average diameter 50-300 .ANG. dispersed in an inorganic oxide film, and a lubricant film. The second protective film is formed by applying a solution containing both an organic compound and the particulates and subjecting it to a heat treatment. The medium has a maximum surface roughness of 100-300 .ANG. and no surface protrusions or unevenness high than 760 .ANG. and is usable for contact recording with a recording head having flying height of less than 760 .ANG..
    Type: Grant
    Filed: September 26, 1991
    Date of Patent: May 31, 1994
    Assignee: Hoya Electronics Corporation
    Inventors: Hisanori Suzuki, Takeo Matsudaira
  • Patent number: 4945432
    Abstract: A magnetic disk drive of the Winchester type has magnetic disks layered around the external peripheral surface of a spindle and separated mutually from one another by spacers. The substrate of the magnetic disks are made of non-metallic materials such as glass or ceramics but do not break easily by the motion of the spindle or the change in temperature because either the adhesive used to form a unistructural assembly of the magnetic disks and the spacers or elastic members inserted in annular indentations formed in the spacers serve as a buffer when the magnetic disks and the spacers are compressed together.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: July 31, 1990
    Assignee: Hoya Electronics Corporation
    Inventors: Takeo Matsudaira, Hiroshi Kouno, Shinji Eda, Juuzoh Funayama