With the development of economy and the improvement of automation degree, rotary encoder obtained rapid development in the market.

Based on principle of electromagnetic induction rotary encoder is a kind of precision measuring angular displacement sensor, in the rotor and stator windings. If sine excitation current in the rotor winding zhongtong, the rotor in the stator winding induction voltage with frequency, but the phase and amplitude changes with the relative displacement of the stator and rotor. Induced voltage phase or as A picture and the electronic circuit such as A/D conversion, the output of several digital signal (absolute value), or output has certain phase difference and the frequency difference of multiphase pulse or sine signal.

Feedback sensor, rotary encoder as speed and displacement is mainly used in the servo motor, asynchronous motor, stepping motor, elevator traction machine, elevator door machine and mechanical shaft need the automation control of the movement speed and displacement information feedback, to ensure the high precision of mechanical stability, and improve production efficiency and safety operation. Mainland companies in the early 1950 s, started in the production field of rotary encoder, due to the mainland market automation industry development level is low, rotary encoder scale and growth are restricted by a certain degree.

Into the 90 s of the 20th century, with China automation industry rapid development, the application of CNC and the servo system, the requirement of precision CNC machinery equipment is increasing, the rotary encoder products greatly improved its application proportion, rotary encoder of the size of the market is expanding fast. Foreign rotary encoder manufacturers are starting at this time in the domestic set up offices, intensify the promotion in mainland China market. Rotary encoder in mainland market momentum of rapid development has attracted more foreign manufacturers to enter the mainland market, after 2007, the fort union, cooper and other manufacturers have set up branches and offices in domestic, at the same time, China also emerged many domestic manufacturers of rotary encoder, the market more competitive.