公开(公告)号：US4006293A

公开(公告)日：1977-02-01

申请号：US568727

申请日：1975-04-16

申请人： Gijsbertus Bouwhuis ,  Josephus Johannes Maria Braat ,  Peter Ferdinand Greve ,  Kornelis Antonie Immink

发明人： Gijsbertus Bouwhuis ,  Josephus Johannes Maria Braat ,  Peter Ferdinand Greve ,  Kornelis Antonie Immink

IPC分类号： H04N5/85 ,  G02B7/36 ,  G11B7/005 ,  G11B7/09 ,  G11B7/13 ,  H04N5/76 ,  G11B7/12

CPC分类号： G11B7/13 ,  G11B7/005 ,  G11B7/0917

摘要： An apparatus is described for reading a flat record carrier on which information is stored in an optically readable track-shaped information structure. By the arrangement in the far field of the information structure and at one side of a plane which is formed by the optical axis of an objective system which is used for reading and a line parallel to the center line of the track portion to be read, of a radiation-sensitive detection system which consists of at least two detectors in approximately the position .beta./2, .beta. being the angle at which a first-order beam is diffracted in the lateral direction of the tracks, centering and focussing errors can be detected without the use of auxiliary beams and additional optical elements.

摘要翻译： 描述了一种用于读取以光学可读的轨道形信息结构存储信息的平面记录载体的装置。 通过在信息结构的远场中和在由用于读取的物镜系统的光轴和平行于要读取的轨道部分的中心线的直线形成的平面的一侧， 由大约β/ 2位置的至少两个检测器组成的辐射敏感检测系统，β是在轨道的横向上衍射一阶光束的角度，可以检测定心和聚焦误差 而不使用辅助光束和附加的光学元件。