METHOD FOR DETECTING TANGENTIAL TILT OF OPTICAL DISK DRIVE AND SUITABLE APPARATUS THEREOF

摘要

PURPOSE: A method for detecting tangential tilt of an optical disk drive and suitable apparatus thereof are provided not to necessary for an additional tilt detecting sensor by detecting a tangential tilt using a synchronous signal recorded in a header region of a disk. CONSTITUTION: A reproduction signal generator(140) generates signals, a subtracted signal and an added signal generated in light receiving devices of 4-divided optical detector. A header interval signal generator(152) generates a header interval signal for indicating a header region from a push-pool signal generated in the reproduction signal generator (140). A first synchronous signal level detector(144) detects a size (V1) of a synchronous signal among signals provided from a switch(S3) after being synchronized to the header interval signal(12) generated by the header interval signal generator(142). A second synchronous signal level detector(146) detects a size (V3) of a synchronous signal among signals provided from a switch(S1) after being synchronized to the header interval signal(34) generated by the header interval signal generator(142). A balance operating unit(154) operates a ratio between the V1 detected by the first synchronous signal level detector(144) and the V3 detected by the second synchronous signal level detector(146). A comparing unit(156) compares a balance value(T1) operated by the balance operating unit(164) with a predetermined reference value(T0) and outputs a difference of two values(T0,T1). A polarity inverting unit(160) inverts a polarity of the difference value outputted from the comparing unit(156). A tangential tilt adjusting unit(134) adjusts a tangential tile according to the polarity-inverted difference value. A mirror interval signal generator(150) generates a mirror interval signal for indicating a mirror region from the addition signal generated from the reproduction signal generator (140).