公开(公告)号：US4800256A

公开(公告)日：1989-01-24

申请号：US938930

申请日：1986-12-08

申请人： Eric C. Broockman ,  Robert T. Cato ,  William D. Gregory, Jr. ,  George J. Laurer

发明人： Eric C. Broockman ,  Robert T. Cato ,  William D. Gregory, Jr. ,  George J. Laurer

IPC分类号： G02B26/10 ,  G06K7/016 ,  G06K7/10 ,  G06K7/12

CPC分类号： G06K7/10871 ,  G02B26/106

摘要： An improved holographic scanner includes circuitry for adjusting the frequency with which an analog photodetector signal is sampled in accordance with the focal length of the scanning beam produced by the active holographic facet. Two embodiments are shown. In one embodiment, facet-edge signals are used to track the facets. A processor retrieves a predetermined frequency scaling factor appropriate for each facet. In the other embodiment, a holographic disk carries an auxiliary data track. The track has timing indicia with spatial frequencies dependent upon the focal length of the adjacent facet. The timing indicia are used to control the output of a voltage controlled oscillator in a circuit including a phase locked loop.

摘要翻译： 改进的全息扫描器包括用于根据由有源全息小面产生的扫描光束的焦距调整模拟光电检测器信号被采样的频率的电路。 示出了两个实施例。 在一个实施例中，小面边缘信号用于跟踪小平面。 处理器检索适合于每个小面的预定频率缩放因子。 在另一个实施例中，全息盘携带辅助数据轨道。 轨道具有定时标记，其空间频率取决于相邻小面的焦距。 定时指示用于控制包括锁相环的电路中的压控振荡器的输出。