| 摘要 |
PURPOSE:To omit a labor of previously measuring an optimum power by automatically controlling power of a laser light to hold a detecting time at a predetermined value. CONSTITUTION:When a unrecorded part is irradiated with a strong level of a laser light at the time of recording, a time to be elapsed before thermally modification of the unrecorded part is detected by a time (tau) detector 4. This time (tau) is constant if data writing on an optical disk by the power of the light is optimum, but if the power is varied, the time (tau) is varied. Then, a laser light irradiating time on the unrecorded part detected by the detector 4 is fed back to a laser power controller 5, and the power of the light is controlled so that the detecting time (tau) is held at a predetermined value by the controller 5. Thus, the light is always controlled to optimum power for data writing on the disk 1, and the labor of previously measuring the optimum power is omitted. |
