| 摘要 |
An absolute position length measurement type encoder includes: a scale in which an ABS pattern based on a pseudorandom code is provided; a light-receiving element for receiving bright and dark patterns formed by the scale; and a signal processing circuit for processing signals subjected to output of the light-receiving element and measuring an absolute position of the scale to the light-receiving element, wherein the signal processing circuit includes a space-dividing number conversion circuit that obtains finer intervals D than the array interval PPDA of the ABS light-receiving element array of the light-receiving element, and simultaneously obtains and outputs a digital value for each of the intervals D subjected to output of the ABS light-receiving element array. Therefore, even where the minimum line width of the ABS pattern is not an integral multiple of the array interval of the ABS light-receiving element array, an arithmetic operation for the correlation can be carried out, and the moving distance can be measured at high accuracy.
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