| 摘要 |
A position sensor has a detector having a plurality of sensitive elements which are acted on by indicia of a scale so that each sensitive element detects overlap between itself and one or more indicia of the scale. The outputs of the sensitive elements are modified by weighting values so that there is one position of detector and scale where the sum of the outputs has a unique characteristic. This position can be detected by means analyzing the sum of the outputs, and can then detect displacement of scale and detector from that one position. The indicia used have a non-uniform pattern, but other indicia with a pitch less than twice but not equal to the pitch of the sensitive elements may be provided to permit interpolation to fractions of the pitch of the sensitive elements. Further interpolation may be provided by a register through which signals propagate at a rate which is a multiple of the rate they are received. The register elements modify the signals by weighting values and the sum of the register element outputs is determined. |
