发明名称 |
Defect detection device |
摘要 |
The defect detection device includes: an amplification section for amplifying a reflection signal corresponding to the intensity of light reflected from an optical disc according to a control signal indicating recording or playback; an envelope detection section for outputting an envelope of the amplified signal; a first pulse generation section for outputting a pulse when the level of the control signal changes; an integration section for integrating the envelope; a differential signal generation section for receiving the envelope as a first input signal and the integrated results as a second input signal and outputting a differential signal corresponding to the difference between these signals; and a comparison section for comparing the differential signal with a predetermined value and outputting the results as a defect detection signal. The second input signal is changed so as to reduce the possibility that the defect detection signal may indicate the presence of a defect over the duration of the pulse.
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申请公布号 |
US2005030865(A1) |
申请公布日期 |
2005.02.10 |
申请号 |
US20040899008 |
申请日期 |
2004.07.27 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
IZUMI TERUHIKO |
分类号 |
G11B7/004;G01N21/84;G01N21/95;G11B5/58;G11B7/0037;G11B7/09;G11B27/36;(IPC1-7):G11B5/58 |
主分类号 |
G11B7/004 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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