Optical disk player

TL;DR: In this article, the authors proposed a method to shorten the time required for optimizing a liquid crystal refractive index for improving signal characteristic values of a light receiving signal in an optical disk player.

Abstract: PROBLEM TO BE SOLVED: To shorten the time required for optimizing a liquid crystal refractive index of a liquid crystal element for the purpose of improving signal characteristic values of a light receiving signal in an optical disk player SOLUTION: The optical disk player adjusts the liquid crystal refractive index of the liquid crystal element so as to become minimum refractive index (#1), and stands by till the liquid crystal refractive index of the liquid crystal element is stabilized (#2), after that, the liquid crystal refractive index of the liquid crystal element is adjusted so as to become maximum (#3), and jitter values of RF signals are measured multiple times during a period till the liquid crystal refractive index becomes maximum refractive index from the minimum (#4) Then, based on these measurement results (based on the jitter values of the measured RF signals and an elapsed period from the time adjusted so that the liquid crystal refractive index becomes maximum, to the time when the jitter values of respective RF signals are measured), the optimum refractive index which is a liquid crystal refractive index when the jitter value of the RF signal becomes minimum (optimum), is calculated (#5 to #7) and the liquid crystal refractive index of the liquid crystal element is adjusted so as to become optimum (#8) COPYRIGHT: (C)2009,JPO&INPIT