Renesas Electronics Corporation

Mitsuyuki Kimura

Yoshimi Iso

Mitsuo Hagiwara

The optical disc device has a circuit which forms a focus error signal for focus servo control based on reflection light from an optical disc exposed to laser light. Also, the device has a data processing unit which can control by feedback a position to which an objective lens is moved by a focusing actuator based on a focus error signal. In label printing, the data processing unit controls, by feedforward, a position to which the objective lens is moved by the focusing actuator based on control data for label printing. The operation resolution of the focusing actuator in feedforward control is made higher than that in feedback control. Thus, an intended position control accuracy is achieved in feedforward control. For instance, in feedforward control, the gain of the driver circuit for the focusing actuator is switched to a smaller one in comparison to that in feedback control.

Optical disc device

The optical disc device has a circuitwhich forms a focus error signal FER for focus servo control based on reflection light from an optical disc exposed to laser light. A data processing unitcan control by feedback a position to which an objective lens is moved by a focusing actuatorbased on the focus error signal. In label printing, the data processing unit controls, by feedforward, a position to which the objective lens is moved by the focusing actuator based on control data for label printing. The operation resolution of the focusing actuator in feedforward control is made higher than that in feedback control. Thus, an intended position control accuracy is achieved in feedforward control. For instance, in feedforward control, the gain of the driver circuitfor the focusing actuator is switched to a smaller one in comparison to that in feedback control.

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Tokyo, Japan

Mitsuyuki Kimura