Single-track absolute grating scale and image coding method thereof

Abstract

A single-track absolute grating scale and image encoding method thereof, comprising a light source, a reflector, incremental scale grating lines, a glass substrate, a movable diaphragm, a photoelectric receiver, and an indication grating; the light source and the reflector are combined into an illumination light path; the incremental scale grating lines having the same width are engraved on the glass substrate at equal intervals; milestone flags are engraved in parallel at equal intervals below the incremental scale grating lines on the glass substrate; the indication grating is embedded in an opening at the left upper part of the movable diaphragm; an upper and a lower CMOS sensors are respectively embedded in an upper and a lower symmetrical openings on the right of the movable diaphragm; the indication grating is installed closely against the glass substrate; the installation position of the upper CMOS aligns to the incremental scale grating lines; the installation position of the lower CMOS aligns to the milestone flags; and the light beams of the incremental scale grating lines and the indication grating form Moire fringes projected onto the photoelectric receiver. The present invention improves the acquisition speed of image information, improves code measurement accuracy, and can reliably encode, simply decode and quickly output a result.

Description

Technical field [0001] The present invention is a single-track absolute grating ruler and an image coding method thereof, and belongs to the transformation technology of a single-track absolute grating ruler and its image coding method. Background technique [0002] The basis of the metrological grating technology is the Moiré fringe. In 1874, the British physicist L. Rayleigh first proposed the engineering value of this pattern. It was not until the 1950s that people began to use the moiré fringe of the grating for precision measurement. In 1950, Germany Heidenhain pioneered the DIADUR copying process, which is a photolithographic copying process that evaporates chromium plating on a glass substrate. Only this can produce high-precision and inexpensive grating scales, and grating measurement instruments can be accepted by users and enter the commodity market. In 1953, the British Ferranti Company proposed a 4-phase signal system, which can realize 4 times frequency subdivision i...

AI Technical Summary

Problems solved by technology

However, due to the relative complexity of single-track absolute encoding, cumbersome decoding methods, and high error rate, it is still not widely popularized.

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