| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk evaluation device which can perform reliable disk evaluation even to a recording disk recorded with high density recording. SOLUTION: An amplitude limiting reading sample value series, in which each of the sample values of the read sample value series acquired by sampling a read signal read from the recording disk at clock timing with frequency identical to 66 MHz channel clock is limited to the designated amplitude limiting value or below, is acquired. At this stage, when an interval of the maximum sample and the minimum sample in the amplitude limiting reading sample value series is in a designated higher frequency interval, the high frequency emphasis read sample value series acquired by applying the high frequency emphasis processing for increasing the values of these maximum and the minimum samples, respectively, are converted to an analog high frequency emphasis read signal at the clock timing with the frequency identical to the channel clock. Only a component below cutoff frequency of 27-33 MHz in the high frequency emphasis read signal is made an evaluation reading signal and jitter for a binarized signal in which this evaluation reading signal is binarized by the designated threshold value is made a disk evaluation value. COPYRIGHT: (C)2006,JPO&NCIPI
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