JPS6427015A - Production of erasing head - Google Patents

Abstract

PURPOSE:To produce an erasing head having plural magnetic poles the polarities of which are alternately reverse from each other at a low cost by previously magnetizing a thin magnetic film layer in one direction, projecting light on the thin magnetic film layer via a slit plate and applying a bias magnetic field in the direction reverse from the magnetization direction of the thin magnetic film layer on said layer. CONSTITUTION:The thin magnetic film layer 2 having a required thickness is formed on the surface of a head base plate 1 on the side where the surface comes into contact with a tape. Said layer is so magnetized that the magnetization direction is perpendicular to the film plane, for example, in a downward direction. The slit plate 3 having many parallel and rectangular slits 4 is disposed above said layer 2 in proximity thereto and the light is projected thereon from a light source 5 disposed above the plate. The external bias magnetic field Hb is further impressed on this layer 2 in the direction opposite to the magnetization direction of the layer. The plural magnetic poles the polarities of which are alternately reversed from each other are thereby formed on the layer 2. The production process is thus simplified and the cost thereof is reduced; in addition, the setting of the number of inversions of the magnetic poles is easy.