| 摘要 |
PURPOSE:To perform the light modulation overwriting with a low error ratio at the recording and reproduction by making the laser deletion power to be applied in the case of a short recording pit interval shorter than that in case of a long recording pit interval. CONSTITUTION:An optical disk capable of light modulation overwriting is irradiated with the higher laser power in the case of forming a recording pit and with the lower laser power than the recording time in the case of deletion. In short, the recording pit is recorded at the temperature higher than T1, and deleted within the temperature range from lower than T1 and up to T2. When a recording bit is short, the location which is originally under the T2 is fluctuated by the thermal interference between recording bits, increasing an error ratio. This tendency is remarkable in the optical disk capable of light modulation overwriting since the optical disk is irradiated with laser for deletion during recordings. An error ratio is reduced if the laser power at the deletion is controlled so as to prevent the excess temperature rise of the deletion section of a recording film. |
