Transversal push-pull method for optical pickup

The authors have developed the transversal push-pull (TPP) method for removing track offset. The basic principle and characteristics of the TPP method are described. The proposed method has the following features: (1) ability to remove track error offset caused by objective lens shifting; (2) no chance for track error offset in recording on a write-once disk, because of one-beam scanning; (3) no limitation of spot size on the photodetector (therefore, the effect of photodetector movement is depressed); and (4) application to a compact disk system. The TPP has negligible offset in playing back compact disks.<>