| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical encoder capable of detecting abnormality of an optical system by easy means without adding components, in the optical encoder for detecting a rotation position with a high resolution by executing interpolation computing to two sinusoidal signals with a 90-degree phase difference. <P>SOLUTION: An optical absolute encoder comprises: a square sum computing unit for squaring and adding two sinusoidal signals with the 90-degree phase difference respectively; an abnormality signal memory for recording an abnormality level of signals; and an abnormality determination device for determining abnormality of the signals. When an arithmetic result obtained in the square sum computing unit is below a value recorded in the abnormality signal memory, the abnormality determination device outputs abnormality signals. <P>COPYRIGHT: (C)2013,JPO&INPIT |
