Patent ID: 7272087

Claim:
An ADIP (address in pre-groove) signal detection circuit for a wobble detection system of an optical disc apparatus, the ADIP signal detection circuit comprising: a delayer, which delays a wobble signal by a predetermined time period; a first window comparator, which compares the wobble signal with a positive reference level to generate a first comparison signal and compares the wobble signal with a negative reference level to generate a second comparison signal; a second window comparator, which compares the positive reference level with an output signal of the delayer to generate a third comparison signal and compares the negative reference level with an output signal of the delayer to generate a fourth comparison signal; a first edge detection circuit, which receives the first comparison signal and the third comparison signal and detects edges of the first comparison signal; a second edge detection circuit, which receives the second comparison signal and the fourth comparison signal and detects edges of the second comparison signal; a first discontinuous point determination circuit, which generates a signal corresponding to a positive discontinuous point of the wobble signal when two successive edges among the edges detected by the first edge detection circuit exist in a predetermined time interval; and a second discontinuous point determination circuit, which generates a signal corresponding to a negative discontinuous point of the wobble signal when two successive edges among the edges detected by the second edge detection circuit exist in the predetermined time interval.