Image collecting circuit of high-speed absolute grating ruler

Abstract

The invention relates to an image collecting circuit of a high-speed absolute grating ruler. Coarse code channels and high-precision absolute code channels are engraved in the grating ruler. A photoelectricity converter for reading images and two LED light sources are further installed on the grating ruler. Multiple data reading windows are arranged in the photoelectricity converter. The image collecting circuit comprises a circuit switching device, a first A / D converter, a second A / D converter, a phase detector, a first position detector, a counting device, a second position detector, a speed detector, a correcting processor, a phase correcting processor, an absolute position detector, a speed judging device, a coding and decoding device and a storage device. Phases output by the photoelectricity converter are used for finely dividing adjacent absolute coding engraving line intervals to improve measuring precision of the grating ruler, macro-micro composite reading on low-precision incremental code channels and high-precision absolute code channels is achieved with a reading head. In a low-precision measuring stage, high measuring speed is achieved and low-speed high-precision measuring is carried out by switching when an endpoint is close.

Description

technical field [0001] The invention is an image acquisition circuit of a high-speed absolute grating ruler, which belongs to the innovative technology of the image acquisition circuit of a high-speed absolute grating ruler. Background technique [0002] In 1874, Rayleigh (L. Rayleigh) used Moiré fringes for measurement for the first time, and since then there has been Moiré metrology. In 1953, the British Ferranti company invented the multiple reversible counting system, which made a breakthrough in the electronic system corresponding to the metering grating. The company's Edinburgh laboratory designed and built the first prototype to measure displacement using a Moiré fringe system. In the 1960s, NPL in the UK successively developed photoreticle reticle devices for circular gratings and long gratings, which broke through the manufacturing problem of grating masters. GuilD and Buech J.M conducted research on a series of theories of Moiré fringes. At the same time, Buss...

AI Technical Summary

Problems solved by technology

This measurement method is simple and easy, but in the use of CNC machine tools, it is necessary to return to the absolute zero point and reposition each time, so it is difficult to greatly improve the working efficiency of the machine tool

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