Dither signal detecting device and method

A device and method for detecting the dither signal are disclosed. The slope and peak of a digital dither signal which is read out from CD or DVD and has been processed by band-pass filter and A/D converter are detected. If the value calculated according to the gap between current peak and previous peak is a bit length that is the integer times of 3, the class conversion is delayed by a certain bit length to enable it to detect and output the rectangular-wave dither signal whose pulse width is the bit length that is the integer times of 2. It can also simplify the address decoder. 本发明是关于一种抖动信号检测装置及方法。检测从可以录制的CD或DVD等光盘读出的并经带通滤波及A/D转换的数字抖动信号的斜率及峰值，若当前检测的峰值与先前已经检测的峰值之间间隔的频率计算的数值成3的正数倍比特长度时，以一定的比特长度延迟级别转换，使其能够检测并输出具有2的正数倍比特长度脉宽的矩形波抖动信号，即使在上述A/D转换的数字抖动信号中存在低频波或直流偏移成分，或是振幅变动等情况下，也能够不仅可以稳定地检测抖动信号，而且还可以把解码光盘物理地址的地址解码器的结构更简化。