发明名称 |
Process and optical device for generating signals controlling the position of a scanning spot of the tracks of a data carrier |
摘要 |
The process makes it possible to generate on the basis of discrete preetching elements or flags, the radial tracking error and/or focusing error signals. The flags comprise portions displaced with respect to the mean axis of the tracks to be followed. According to a first variant, each track comprises portions displaced on either side of the axis. According to a second variant the flags comprise portions alternately displaced to one and then the other side thereof. In response to the passages of these portions, windows are generated and the pulses supplied by the photodetectors of the interaction of these portions on the focused scan beam are compared between successive windows.
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申请公布号 |
US4562564(A) |
申请公布日期 |
1985.12.31 |
申请号 |
US19830473539 |
申请日期 |
1983.03.09 |
申请人 |
THOMSON-CSF |
发明人 |
BRICOT, CLAUDE;BERTHET, PIERRE;GERARD, JEAN-LOUIS |
分类号 |
G11B7/085;G11B7/00;G11B7/004;G11B7/007;G11B7/08;G11B7/09;G11B27/19;G11B27/30;(IPC1-7):G11B7/00 |
主分类号 |
G11B7/085 |
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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