| 摘要 |
Absolute optical encoder device using a line array detector in conjunction with a single strip of encoding bars. The bars are orthogonal to the detector array line and may be long enough to allow motion parallel to the bars without loss of measurement continuity. High resolution is achieved by combining use of a small difference between the detector element spacing and the bar spacing in selected regions to produce a vernier effect, enabling measurement to the precision of a fraction of a detector element. High resolution is further achieved by traverse of a vernier regin edge across a multiplicity of detector elements upon which adjacent vernier regions are optically superimposed, and by identification of each vernier region as a unique member of a numbered series using distinguishable patterns in the space between vernier regions or in the structure of the vernier regions themselves.
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