| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the lowering of a detection accuracy even if a scale is contaminated or the like, or even if a pattern on the scale is something like an integrated pattern, to keep a detection head compact, and to reduce the stopping of a control machine to which an encoder is mounted, due to an error. <P>SOLUTION: A detection head 120 includes a plurality of light-receiving array sections PDi (i=1-4) aligned in a relatively displaceable direction, a position signal xi indicating the position x of the detection head 120 is calculated by output signals output from the light-receiving array sections PDi respectively to synthesize a plurality of position signals xi, when determining the position x of the detection head 120 with respect to a scale 110, the position signals xi for every light receiving array sections PDi are weighted (a reliability coefficient Ri) according to the dimension of the output signals, and the weighted position signals xi are averaged. <P>COPYRIGHT: (C)2012,JPO&INPIT |
