Slider servo device.

摘要

In a slider servo device the deviation of an information reading spot (S1) of a pickup from a recording track of an information recording disk in the radial direction of the disk is corrected by a servo amplifier (13) for receiving a low-band component of a tracking error signal corresponding to the quantity of deviation. The servo amplifier (13) has a first gain and a second gain smaller than the first gain and, the slider servo device also has a slider unit (17) for moving the pickup in the radial direction of the disk depending upon the level of the output from the servo amplifier. The slider unit (17) has a dead zone such that an output for driving the pickup cannot be generated until the absolute value of the level of the input to the slider unit reaches a prescribed magnitude. The first gain is selected for high-speed movement of the pickup, and the second gain is selected for the normal-speed movement or low-speed movement of the pickup. In another embodiment of the invention, the first gain is selected when the level of the input to the amplifier (13) is low and the first gain is replaced by the second gain when the absolute value of the level of the input from the amplifier (13) is proximate to the prescribed magnitude of the level of the input to the slider unit (17).