The invention discloses a displacement sensor, a
galvanometer motor system, an assembling method and a
signal processing method, the displacement sensor is connected with a
motor shaft and adopts a transmission-type
grating sandwich structure, and the transmission-type
grating sandwich structure comprises a
light source module which is arranged on the upper layer and comprises an aspheric collimating lens capable of generating uniform parallel light beams; the
grating code disc is arranged on the middle layer and made of an
optical glass substrate, and the grating code disc is fixed on the
motor shaft through a code disc tray; the photoelectric receiving module is arranged on the lower layer, the photoelectric receiving module comprises a plurality of groups of orthogonally arranged photodiodes and photoelectric
converters, the photodiodes are used for receiving light and shade changes of light stripes and forming optical signals, and the photoelectric
converters are used for receiving the optical signals and converting the optical signals into electric signals. According to the invention, the size of the structure can be reduced, the position
subdivision precision is improved, the
signal processing speed and the anti-interference capability are improved, and thus the use effect of the
galvanometer motor system is improved.