Renesas Assigned Patent
Optical disc device
By Francis Pelletier | October 28, 2015 at 2:48 pmRenesas Electronics Corporation, Kanagawa, JP, has been assigned a patent (9,153,271) developed by Iso, Yoshimi, Tokyo, Japan, Hagiwara, Mitsuo, and Kimura, Mitsuyuki, Tokyo, Japan, for a “optical disc device.”
The abstract of the patent published by the U.S. Patent and Trademark Office states: ”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.“
The patent application was filed on June 6, 2014 (14/298,316).