| 摘要 |
PURPOSE:To perform magnetic recording or the same recording of a laser disk, etc., by laminating a magnetic recording layer and an optical recording layer successively from the surface, and providing a laser which generates a compatible output for optical and magnetic recording and reproduction. CONSTITUTION:A head 7 for a magnetic recording layer 2 which is arranged in contact with or nearby the surface of a recording medium 1 supplies a write magnetic field to the layer 2 or detects a leak magnetic field. A head 6 for an optical recording layer 4, on the other hand, controls the laser light of a laser oscillator 9 so as to form an optical path 8 of transmission and reflection. The laser light is laser output satisfying P>=Ed+Lm+Le (P: output of oscillator 9, Ed: input laser light energy required by reflected light detector and amplifier, Lm: energy loss during reciprocation in layer 2, and Le: total of light energy loss except loss Lm). The expression controls both condition of optical recording and reproduction and magnetic recording and reproduction and this expression is satisfied to realize both recording and reproducing systems. |
