| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk evaluation device capable of highly reliable disk evaluation even for a recording disk to which high density recording is performed. SOLUTION: An amplitude limit read sample value sequence for which a read sample value sequence obtained by sampling read signals read from the recording disk at the clock timing of the same frequency as a channel clock is limited by a prescribed amplitude limit value is obtained. In this case, when the interval of a maximum sample value and a minimum sample value in the amplitude limit read sample value sequence is pertinent to a prescribed high band wavelength interval, a high band emphasized read sample value sequence for which a high band is emphasized by increasing the maximum sample value and the minimum sample value is obtained. Then, the high band emphasized read sample value sequence is converted to analog high band emphasized read signals at the clock timing of the same frequency as the channel clock and only the components of a prescribed cutoff frequency or below in the high band emphasized read signals are obtained as evaluation read signals. Then, the jitter of binary signals for which the evaluation read signals are binarized by a prescribed threshold is outputted as a disk evaluation value. COPYRIGHT: (C)2004,JPO
|
