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Magnetic recording disc and method of making same

  • US 4,338,643 A
  • Filed: 04/08/1980
  • Issued: 07/06/1982
  • Est. Priority Date: 11/16/1976
  • Status: Expired due to Term
First Claim
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1. A method of producing a magnetic recording disc comprising applying a magnetic layer containing magnetic particles on a support film base, orienting the magnetic particles in a number of first strip-like zones in a first direction and in a number of second strip-like zones in a second direction inclined with respect to the first direction at an angle of 60°

  • to 120°

    , said first and second strip-like zones being alternately and contiguously arranged in parallel to each other, the width of each said first and second strip-like zones being not more than 5 mm and the ratio of the width of the first strip-like zone to that of the second strip-like zone being within the range of 1;

    3 to 3;

    1, solidifying the magnetic layer after the magnetic particles in said first strip-like zones, causing interaction along the boundaries between adjacent strip-like zones resulting in a random particle orientation and then stamping out a magnetic recording disc from the support film base, whereby positioning of a disc center hole is greatly fascilitated and the output is enhenced.

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