| 摘要 |
PROBLEM TO BE SOLVED: To provide a jitter measuring device for an optical disk playback device which measures jitters that is included when pit information recorded on an optical disk is reproduced, which changes settings of the equalizer characteristics, binarizing characteristics and loop characteristics of a PLL circuit easily for the devices to be measured having especially different jitter measurement standards and which make the measurement of jitters of optical disk playback devices having different specifications possible by employing a single measuring device. SOLUTION: A media/linear velocity discriminating circuit 15 discriminates the type and linear velocity of the device to be measured and outputs the measured results to a control section 17 through a CPU16. The section 17 changes the boost frequency of an equalizer/filter circuit 11, the cutoff frequency of a binarizing circuit 12, the loop characteristics of a PLL circuit 13 corresponding to the type and linear velocity of the device to be measured and conducts settings for the circuits corresponding to the jitter measurement standards of the device. Thus, settings of jitter measurement standards corresponding to the device to be measured are performed and jitter measurement of wide range optical disk playback devices is conducted using a single jitter measuring device. COPYRIGHT: (C)2005,JPO&NCIPI
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