Grating displacement measuring device

The invention relates to the technical field of optical detection, in particular to a grating displacement measuring device which comprises a grating ruler and a reading head, and the grating ruler and the reading head can move relatively. The reading head comprises a shell, a cylindrical lens is arranged in the middle of the shell, a photodiode is arranged on the rear side of the cylindrical lens, and more than two light sources are arranged around the photodiode. By arranging more than two light sources, the photodiode compares the signals of each light source and then outputs the final signal, so that the measurement precision is improved; besides, when a signal of a certain light source on the grating ruler is lost due to stains, scratches and splicing gaps, signals of other light sources are still effective, normal work of the grating displacement measuring device can be guaranteed, and the service life of the whole grating displacement measuring device is prolonged. 本发明涉及光学检测技术领域，尤其是指一种光栅位移测量装置，包括光栅尺和读数