公开(公告)号：US5981941A

公开(公告)日：1999-11-09

申请号：US859321

申请日：1997-05-20

申请人： Kazumasa Takata ,  Kanji Nishii ,  Kenji Takamoto ,  Masami Ito ,  Atsushi Fukui ,  Tomohisa Kishi

发明人： Kazumasa Takata ,  Kanji Nishii ,  Kenji Takamoto ,  Masami Ito ,  Atsushi Fukui ,  Tomohisa Kishi

IPC分类号： G01D5/38 ,  G01D5/34

CPC分类号： G01D5/38

摘要： The present invention provides an optical encoder capable of using the recesses and convexes of a movable plate and a fixed plate to accurately generate a Z phase signal in synchronism with an A/B phase signal. Phase type diffraction gratings on the moving and fixed plates including a plurality of tracks with different grating pitches cause parallel coherent beams to interfere with one another, and a light receiving part detects the intensity of light to obtain a plurality of synchronous signals with different periods. On the other hand, the light receiving part detects light spots formed by condensing elements on the movable plate to generates a single pulse per rotation as a reference position. One of the plurality of synchronous signals that has the shortest period is selected as an A/B phase signal that depends on the movement of the movable plate. The conjunction of the reference position signal and the plurality of synchronous signals is determined as a Z phase signal indicating the origin of the movable plate, thereby obtaining a Z phase signal in synchronism with one pulse of the A/B phase signal.

摘要翻译： 本发明提供一种能够使用可移动板和固定板的凹凸的光学编码器，以与A / B相位信号同步地精确地生成Z相信号。 包括具有不同光栅间距的多个轨道的移动和固定板上的相位衍射光栅使平行的相干光束彼此干涉，并且光接收部分检测光的强度以获得具有不同周期的多个同步信号。 另一方面，光接收部检测由可动板上的聚光元件形成的光斑，以产生每旋转一脉冲作为基准位置。 选择具有最短周期的多个同步信号中的一个作为取决于可动板的移动的A / B相位信号。 基准位置信号和多个同步信号的结合被确定为指示可移动板的原点的Z相信号，从而获得与A / B相位信号的一个脉冲同步的Z相信号。