Patent ID: 6603716
Filing Date: 2003-08-05
Classification: G11B

Abstract:
In an optical pickup for writing optical disc record information onto an information record track of an optical disc having prepits based on emission light from a light source or reading the optical disc record information from return light provided by reflecting emission light from the light source on the information record track, an optical pickup direction detection unit for detecting a direction to move the optical pickup in order to position the emission light on the information record track, said optical pickup direction detection unit comprising:a photodetector for receiving the return light and outputting a light detection electric signal; push-pull signal generation means for generating a push-pull signal from the light detection electric signal from said photodetector; prepit signal generation means for extracting a prepit component from the push-pull signal and generating a prepit signal, wherein the prepit component is exclusively a result of a prepit located in a land portion of the optical disc; tracking error signal generation means for generating a tracking error signal from the light detection electric signal from said photodetector, wherein the tracking error signal is based on a continuous guide groove in the optical disc; and optical pickup move direction detection means for detecting the move direction of the optical pickup based on the tracking error signal and the prepit signal.