| 摘要 |
PROBLEM TO BE SOLVED: To easily and reliably detect anomalies, such as, damages and defects to a light-receiving element or a light-projecting element and degradation of the light-projecting element with the passage of time. SOLUTION: The method for determining the state of output of the light-receiving element in a rotary encoder which detects the state of rotation of a shaft to be detected, on the basis of the state of output of each light-receiving element PD, according to the passage and interruption of light projected from the light-projecting element LED to a rotating slit RS includes both a step for determining anomalies during the halt of its rotation and determining that the light-receiving element and the light-projecting element are normal, if the output level of the light-receiving element is equal to or greater than the determination level specified between a zero level and an output level due to a dark current, or the like, of the light-receiving element during the halt of rotation of the rotary encoder and that the light-receiving element or the light-projecting element is anomalous, when the output level of the light-receiving element is less than the determination level, and a step for determining anomalies during its rotating operation and determining that the light-receiving element or the light-projecting element is normal or anomalous, on the basis of on-duty changes in pulse output converted, on the basis of output changes of the light-receiving element during the rotation operation of the rotary encoder. COPYRIGHT: (C)2009,JPO&INPIT
|
