| 摘要 |
PURPOSE:To reduce the thickness of a magnetic tape used for recording and reproducing of a color television signal by using a substrate film formed by laminating a metallic film on a plastic film and specifying the bending rigidity in the longitudinal direction thereof to a specific value or above. CONSTITUTION:The film formed by forming the metallic film by lamination, etc., onto, for example, the plastic film to sufficiently increase the modulus of elasticity within a 2,500-6,000kgf/mm<2> range is preferably used as the substrate film. The overall thickness of the magnetic tape is specified to <=10mum and the bending rigidity in the longitudinal direction expressed by the equation Ext<3>/1291-upsilon<2>) (where E is the Young's modulus of the magnetic tape, t is the thickness of the magnetic tape, upsilon is a Poisson's ratio) is specified to >=0.10gfmm, by which the mechanical strength of the thinnest possible magnetic tape having <=10mum overall thickness is sufficiently intensified to effectively suppress the oscillation during recording and reproducing and to stabilize a head touch. The noise of an amplitude modulation is thus sufficiently decreased.
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