| 摘要 |
PURPOSE:To produce a recess on a film and obtain media for freely recording and playing back by separating the film, on which magnetic substance is applied, by the use of Meissner effect and heating a part of the film to eliminate superconductivity. CONSTITUTION:When a permanent magnetic film 2 is put on superconductive material 1 and the film on which a magnetic film 4 is stuck on a thin plastic film 3 is approached, buoyancy is generated by Meissner effect and a fixed distance is held. When the material 1 is heated to eliminate superconductivity by the use of laser light 5 for writing, only the heated part loses the buoyancy. Recess is produced by the magnetic suction of the magnetic films 2, 4. Since the laser light 5 produces the difference of an optical path only on the recess and the reflected strength is varied, readout is enabled. When the recess is eliminated, current flows in a coil 7 and the magnetic film 4 is drawn to flatten. Therefore, media in which record and playback can freely be performed are obtained. |
