Optical disc device

An optical disc device which can record and reproduce information by irradiating a face of an optical disc with laser light from an objective lens and perform label printing by irradiating the other face of the optical disc with the laser light from the objective lens, comprising:

• a circuit for forming a focus error signal for a focus servo based on a reflection light from the optical disc exposed to the laser light;
• and
• a data processing unit which can feedback-control a position to which the objective lens is moved by a focusing actuator, based on the focus error signal,
• wherein the data processing unit includes:
• an analog-to-digital conversion circuit which converts the focus error signal into digital data;
• a servo control circuit which an output of the analog-to-digital conversion circuit is input to, and which produces servo control data;
• and
• a digital-to-analog conversion circuit which converts the servo control data output by the servo control circuit or control data for label printing into analog signals,
• wherein the optical disc device further comprises:
• a driver circuit which amplifies an output of the digital-to-analog conversion circuit and supplies the resultant signals to the focusing actuator, the driver circuit being arranged so that its gain can be switched,
• wherein when performing the label printing, the data processing unit feedforward-controls a position to which the objective lens is moved by the focusing actuator based on the control data for the label printing which is stored in a memory circuit as digital data and converted to an analog signal with the digital-to-analog conversion circuit,
• wherein when performing the feedforward control, the data processing unit switches and controls a gain of the driver circuit so as to become smaller than the gain of the driver circuit in the feedback control.