| 摘要 |
PROBLEM TO BE SOLVED: To provide a new length measuring device dispensing with a complicated optical system and an operation circuit, and generating no conventional count mistake. SOLUTION: This length measuring device is equipped with a liquid crystal scale wherein pixel rows with a constant pitch comprising the first pixel row and the second pixel row are arranged on the upper and lower sides and each pixel of the first pixel row and each pixel of the second pixel row are arranged on such positions in the length direction that the second pixel row covers the interval in the length direction of the first pixel row, a reading device for reading the pixels in the liquid crystal scale, and an arithmetic unit for processing a signal from the reading device. The length measuring device comprises a circuit for detecting a peak value in the first pixel row and/or the second pixel row by the operation device, a zero detection circuit for detecting a zero point of the first pixel row and/or the second pixel row, and an addition circuit for adding a signal from the arithmetic unit. COPYRIGHT: (C)2005,JPO&NCIPI
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