Abstract: A slider servo device in which a quantity of deviation of an information reading spot of a pickup from a recording track of an information recording disk in the radial direction of the disk is corrected, a servo amplifier for receiving a low-band component of a tracking error signal corresponding to the quantity of deviation is provided. The servo amplifier has a first gain and a second gain smaller than the first gain. The slider servo device also has a slider unit 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 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.

Abstract: An offset compensating circuit in a fine control servo. When the servo loop for an error signal is opened, the error signal is sampled and its positive and negative peaks are found. The average of the positive and negative peaks is determined as an offset signal to be subtracted from the error signal when the loop is closed.