PURPOSE: To reduce the residual magnetism of both left and right track and to reduce distortion of even order and noise by laminating a material with high magnetic permeability, magnet material with gradual alternate gradient, material with high magnetic permeability, and nonmagnetic material to a thickness greater than the width of a tape.
CONSTITUTION: The magnetic material 4' with high magnetic permeability, magnet material 2 with gradual alternating gradient, material 4 with high magnetic permeability, and nonmagnetic material 3 are laminated to the thickness greater than the width of the tape 1, and the thickness of the magnet material 2 is made greater than the outside width of tracks R and L. This magnet material 2 is so magnetized that the N pole and S pole are decreased gradually by turns. Consequently, the residual magnetism of the tracks R and L is reduced uniformly to manufacture a product with less distortion of even order and noise.
MIYATAKE NORIO
KASHIMURA NOBUO
