| 摘要 |
<P>PROBLEM TO BE SOLVED: To monitor displacements between a movable scale and a fixed slit of an optical encoder and excess load related to the displacements without having to use a separately placed displacement sensor. <P>SOLUTION: Light from a light source part is irradiated to the movable scale 1 mounted to a rotating shaft etc. of a fluid bearing motor to generate signal light of an A phase, a B phase, etc. The signal light of each channel is passed through each opening of the fixed slit and made incident onto a light receiving part to generate an electric signal of each phase. The peak of output Vin of any phase is held by a peak hold element and compared with a peak voltage Vref at normal times to acquire an output voltage Vo as monitor output. On the basis of a code and an absolute value of Vo, it is possible to monitor displacements of the movable scale and a rotor in directions along the rotating shaft or the size of load (an external force) exerted on them and detect anomalous displacements, excess load, etc. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
