A Pit-edge Confocal Push-Pull Tracking-error Signal Detection Method for an Optical Pick-up

Abstract

We previously reported that the confocal push-pull (CPP) signals for the tracking-error signals of an optical disk player strongly depend on the parameters of the optical disk system, such as the groove/land ratio (duty ratio) and focus conditions, although CPP signals are very stable in the face of lens displacement. In this paper, improved CPP signal detecting at the pit-edge is reported. This new tracking-error detection method can be applied to an optical disk system in which the optical disk has a pit depth of λ/4n to λ/8n without any phase compensation.