| 摘要 |
PURPOSE:To obtain a good replay signal without a crosstalk by a method wherein a material layer whose phase is changed partially inside a scanning spot by readout light and whose reflection factor is changed is formed on a transparent substrate on which a phase pit is formed. CONSTITUTION:A material layer 13 whose reflection factor is changed by a phase change is formed on a transparent substrate 11 on which phase pits are formed. When an optical disk is irradiated with readout light, the temperature of the material layer 13 is raised, a phase change is caused, and a region whose reflection factor is partially high is produced inside a scanning spot by the readout light. As a result, even when a plurality of phase pits out of the phase pits formed according to a signal are situated inside the scanning spot by the readout light, a reflection change by whether the phase pits exist or not is formed as a signal only inside the region whose reflection factor is high. Thereby, even when a pit cycle is less than a diffraction limit, a good replay signal without a crosstalk is obtained and a recording density can be increased. |
