| 摘要 |
The present invention relates to a digital data play back apparatus for converting a digital data a signal read from a recording medium (1) by sampling (7) in a clock cycle, equalizing (8) this digital data to a waveform which agrees with a partial response class on the basis of the clock (VCO), and detecting data (10) on the basis of the clock (VCO,20) with respect to the equalized signal waveform (8). Then, this apparatus detects a timing phase gradient (18) between the equalized (8) signal waveform and the clock, and controls a clock frequency (20) on the basis of the detected timing phase gradient (18). |
