Rotary switch with circular light guide in stator - directs light to cylindrical rotor reflector which reflects it back to detector

摘要

The rotary switch consists of a cylindrical rotor (2) with a reflector (8) mounted on its circumference and a circular stator (1) enclosing the rotor. Both the rotor and stator are plastic. The stator contains a circular light guide (3) with roughly radial projections (5) that direct light towards the circumference of the stator. When the reflector is in the appropriate position light from one of these projections is reflected back to a photodetector (7) embedded in the stator next to the projection.