| 摘要 |
PURPOSE:To obtain a good head contact by adjusting the cupping amt. of a magnetic recording medium formed by providing a thin ferromagnetic metallic film on an extra thin nonmagnetic substrate having 3.5-9mum thickness to a specific value or below. CONSTITUTION:A ferromagnetic metallic metal 2 such as Fe is formed by vacuum deposition on the substrate 1 consisting of polyethylene phthalate, etc., to form a thin film thereon to 3.5-9mum thickness. The resultant magnetic recording medium is run along a cylindrical can 3 and IR rays are irradiated 4 thereon in the place where the medium is in contact with the can 3. The cupping amt., i.e., the camber (h) when the medium is cut to width W=8mm and is imposed on a flat plate is adjusted to <=2.5mm after preservation for one week under the conditions of 40 deg.C and 80% relative humidity. The contact with the magnetic head is good, and the good recording and reproducing are executed according to the above-mentioned constitution.
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