| 摘要 |
PURPOSE: To generate a thermal structure suitable for optical recording and optical reproducing in an optical disk by including a heat conduction control layer variable in thermal conductivity from the outside within the disk. CONSTITUTION: On the optical disk 11 a heat conduction control layer 6 of which thermal conductivity can be varied from the outside, is arranged between in optical recording film 3 and a light reflection film 7 in common use as a heat sink film. As the result, the adjustment of the diffusion of heat from the optical recording film 3 to the light reflection film 7 is made possible. The heat is diffused via the light reflection film 7. The control layer 6 consists of laminated films of ferromagnetic films 4 and nonmagnetic films 5. As the result, the control layer 6 has a first form of the low thermal conductivity in which the films 4 are magnetically mutually arranged in the antiferromagnetic direction and a second form of the high thermal conductivity in which the films 4 are magnetically mutually arranged in the ferromagnetic direction under impression of external magnetic fields. |
