Patent ID: 9153271
Filing Date: 2015-10-06
Classification: G11B

Abstract:
1. A single-chip data processing unit for use in 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, wherein the single-chip data processing unit can feedback-control a position to which the objective lens is moved by a focusing actuator, based on a focus error signal for a focus servo based on a reflection light from the optical disc exposed to the laser light, the single-chip data processing unit comprising: 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 has: wherein when performing the label printing, the single-chip 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 that of the driver circuit in the feedback control.