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US 6,686,025 B2Granted
Magnetic recording medium
AssigneeFuji Electric Co., Ltd.
InventorAkira Iso
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium that does not develop film swelling when exposed to severe conditions has a nonmagnetic substrate having a trench formed in the area within 2 mm from and concentrically with the outer circumference or the inner circumference of the nonmagnetic substrate, or formed outside the data area concentrically with the outer circumference or the inner circumference of the nonmagnetic substrate.
Claims11
A magnetic recording medium comprising:
- a nonmagnetic substrate made of a plastic resin, the nonmagnetic substrate having a trench extending along the vicinity of an edge of the nonmagnetic substrate;
- a nonmagnetic undercoating layer on the nonmagnetic substrate, the non magnetic undercoating layer coating the trench;
- a magnetic layer on the nonmagnetic undercoating layer;
- a protection layer on the magnetic layer;
- and
- a liquid lubricant layer on the protection layer.
- wherein said medium having a substrate with said trench exhibits reduced swelling caused by absorbed moisture compared to a medium having a substrate without said trench.
4 more elements
A method of manufacturing a magnetic recording medium including a nonmagnetic substrate;
- a nonmagnetic undercoating layer on the nonmagnetic substrate;
- a magnetic layer on the nonmagnetic undercoating layer;
- a protection layer on the magnetic layer;
- and a liquid lubricant layer on the protection, layer the method comprising the steps of:
- providing the nonmagnetic substrate composed of plastic;
- forming a trench extending along the vicinity of an edge of the plastic substrate;
- and
- forming the nonmagnetic undercoating layer on the nonmagnetic substrate, the nonmagnetic undercoating layer coating the trench.
- wherein said medium having a substrate with said trench exhibits reduced swelling caused by absorbed moisture compared to a medium having a substrate without said trench.
6 more elements
A magnetic storage device comprising:
- a magnetic recording medium mounted thereon, the magnetic recording medium including:
- a nonmagnetic substrate made of a plastic resin, the nonmagnetic substrate having a trench extending along the vicinity of an edge of the nonmagnetic substrate;
- a nonmagnetic undercoating layer on the nonmagnetic substrate, the non magnetic undercoating layer coating the trench;
- a magnetic layer on the nonmagnetic undercoating layer;
- a protection layer on the magnetic layer;
- and
- a liquid lubricant layer on the protection layer.
- wherein said medium having a substrate with said trench exhibits reduced swelling caused by absorbed moisture compared to a medium having a substrate without said trench.
5 more elements
Dependencies are inferred from the claim text.