TRACKING ERROR GENERATING DEVICE AND METHOD, SEMICONDUCTOR FOR GENERATING TRACKING ERROR, COMPUTER PROGRAM PERFORMING TRACKING ERROR GENERATION PROCESSING

摘要

PROBLEM TO BE SOLVED: To provide a tracking error generating device in which the manufacturing cost is reduced and accuracy is good, and offset quantity for a reference potential of a tracking error signal can be eliminated.;SOLUTION: First and second analog signals (E13', F14') from a plurality of light receiving means are fetched by an A/D converting means 23 in a timing period positioned at a specific position when an objective lens 2 is shifted in the focus direction, respective maximum values and respective minimum values for temporal variation of first and second digital signals E13'D, F14'D are detected by an extreme value detecting means 43, and offset quantity of the first and second analog signals are changed based on calculated offset compensation values (Vo13, Vo14) so that offset values of the first and the second analog signals coincide with an arbitrary reference potential in an input voltage range of the A/D conversion means based on an extreme value detected result.;COPYRIGHT: (C)2004,JPO&NCIPI