| 摘要 |
PURPOSE:To prevent the quality of an optical master disk from being deteriorated due to the modulation defect of a modulator by adjusting the bias of the modulator based on a bias command means which outputs a clock pulse with a cycle shorter than the rotating cycle of a substrate from a clock pulse generating means. CONSTITUTION:The clock pulse generating means 12 generates the clock pulse with the cycle shorter than the rotating cycle of the substrate, and also, the bias command means 13 outputs the above stated clock pulse based on the clock pulse and the relative movement stopping signal of the substrate with an irradiating position when no laser modulated light is outputted. Also, since the adjustment of the bias of the modulator 2 is performed by an auto bias controller 14 based on the clock pulse from the bias command means 13, no adjustment of the bias is performed during the irradiation of the laser modulated light 1. In addition to that, since the cycle of the clock pulse is short, the modulator 2 can be stabilized while no laser modulated light 1 is outputted. Thereby, the modulation defect due to the modulator 2 can be prevented occurring, and data can be recorded on the substrate with fidelity. |
