发明授权
US4375088A Optically readable record carrier with track variations which provide
clock and tracking signals and apparatus for recording and/or
reproducing data from such a record carrier
失效
具有轨道变化的光学可读记录载体,其提供时钟和跟踪信号以及用于从这样的记录载体记录和/或再现数据的装置
- 专利标题: Optically readable record carrier with track variations which provide clock and tracking signals and apparatus for recording and/or reproducing data from such a record carrier
- 专利标题(中): 具有轨道变化的光学可读记录载体,其提供时钟和跟踪信号以及用于从这样的记录载体记录和/或再现数据的装置
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申请号: US139924申请日: 1980-04-14
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公开(公告)号: US4375088A公开(公告)日: 1983-02-22
- 发明人: Maarten R. de Haan , Klaas Compaan , Leopold H. Hissel
- 申请人: Maarten R. de Haan , Klaas Compaan , Leopold H. Hissel
- 申请人地址: NY New York
- 专利权人: U.S. Philips Corporation
- 当前专利权人: U.S. Philips Corporation
- 当前专利权人地址: NY New York
- 优先权: NLX8000122 19800109
- 主分类号: G11B7/00
- IPC分类号: G11B7/00 ; G11B7/004 ; G11B7/0045 ; G11B7/005 ; G11B7/007 ; G11B7/09 ; G11B7/24 ; G11B7/26 ; G11B19/28 ; G11B20/14
摘要:
Disclosed is a record carrier for storage of digital data which is provided with a first periodic track variation having a period corresponding to a frequency at which the power spectrum of the digital signals is at a zero level. The first track variation produces a corresponding modulation of the radiation when scanned by a beam so that a clock signal can be derived from the detected radiation for synchronizing readout or recording of the data. The record carrier is further provided with a second periodic track variation in a direction transverse to the track direction having a period of the same order of magnitude, and preferably equal to the period of the first periodic track modulation. The second track variation produces a corresponding modulation of the beam which is detected and is used to generate to a tracking signal, the clock signal being used as phase reference signal for demodulation of the tracking signal. If the periods of the two track variations are equal, low-pass filtering automatically yields the tracking signal.