Abstract: The object of this invention is to provide an optical disc apparatus and an optical disc reproducing method that can realize an excellent reproducing operation by suppressing noise in the optical disc apparatus using an optical attenuator. In order to solve this object, a control voltage of the optical attenuator is changed according to reproduction power when reproducing the optical disc and an ambient temperature of the optical attenuator. In addition, the amplitude of a high frequency current for driving a laser diode is changed according to an attenuation factor of the optical attenuator.

Abstract: In laser power control, optical and electronic components are subjected to correction on their temperature characteristics to stabilize write/read characteristics. The present invention comprises a power detector which detects the power of laser light generated by a pickup, a temperature detector which detects the temperature in the pickup, a calculating unit which calculates a target value of the power of laser light generated by the pickup according to the detected temperature, and a power control unit which performs control so that the pickup generates laser light with the power based on the target value. The calculating unit sets a target value so that the characteristics of an objective lens and the power detector in the pickup may be corrected based on their temperature characteristics.

Abstract: According to the present invention, an optimum value of a laser power for recording data on a high-density optical disk can be set with high accuracy. A test signal whose erase power Pe is fixed and recording power Pw is varied is recorded on the optical disk. The recorded signal is reproduced and a ? value representing asymmetry of the reproduced signal is obtained for each recording power. An optimum recording power Pwo is set from a recording power with which the obtained ? value becomes a target ? value. Hereby, the fixed erase power Pe is determined from measurement results of a value of a modulation factor M of another test signal recorded. Alternatively, the fixed erase power Pe follows strategy information defined in advance for the optical disk. Or Pe?0 is used regardless of the optical disk.

Abstract: The object of this invention is to provide an optical disc apparatus and an optical disc reproducing method that can realize an excellent reproducing operation by suppressing noise in the optical disc apparatus using an optical attenuator. In order to solve this object, a control voltage of the optical attenuator is changed according to reproduction power when reproducing the optical disc and an ambient temperature of the optical attenuator. In addition, the amplitude of a high frequency current for driving a laser diode is changed according to an attenuation factor of the optical attenuator.