Abstract: A disk recording system for disks such as videod isks or compact disks has a turntable on which the disk is supported adjacent a recording head. A shaft defining the axis of rotation of the turntable rotates in a bearing and that bearing is itself movable about an axis defined by another shaft. The bearing of the shaft is an air bearing and there is a damper unit for damping that movement. There may be a sensor for detecting the rate of rotation of the shaft defining the axis of rotation of the turntable. The radial displacement of the head relative to the axis of the turntable may be determined on the basis of rotation of the other shaft, and the rotation of the turntable controlled on the basis of the product of signals representing the radial displacement and the rate of rotation of the shaft, respectively.

Abstract: A method and apparatus are provided for controlling the rotation of a turntable relative to a recording head in a disk recording system. A first, voltage signal is generated corresponding to the radial displacement of the recording head relative to a turntable axis, and a second, frequency signal is generated corresponding to the rate of rotation of the turntable. A further voltage signal is then generated which represents the multiplication product of the radial displacement and the rate of rotation of the turntable based on the first and second signals. The rotation of the turntable is controlled in dependence on a difference between the multiplication product and a reference value.

Abstract: A disk recording system for disks such as videodisks or compact disks has a turntable on which the disk is supported adjacent a recording head. A shaft defining the axis of rotation of the turntable rotates in a bearing and that bearing is itself movable about an axis defined by another shaft. The bearing of the shaft is an air bearing and there is a damper unit for damping that movement. There may be a sensor for detecting the rate of rotation of the shaft defining the axis of rotation of the turntable. The radial displacement of the head relative to the axis of the turntable may be determined on the basis of rotation of the other shaft, and the rotation of the turntable controlled on the basis of the product of signals representing the radial displacement and the rate of rotation of the shaft, respectively.