A New Servo Method Which Increases Track Following Range Of A One-Beam Optical Head

A simple and reliable optical head is needed for practical application of optical mass data storage. The so-called push-pull tracking method is widely used in pregrooved disc systems. A disadvantage of this tracking method is that track following range is limited to a few tens of microns, which is too little for practical use. The limited range is due to disc eccentricity, which displaces the axis of the reflected beam. The authors have overcome this problem by a new servo method which compensates electrically the undesirable influence by detecting the displacement from the driving signal of the tracking actuator, and have improved the track following range to 350 μm.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.