Displacement sensor using semiconductor laser light source - has thermal insulator between laser light source and optical grating measuring scale

摘要

The sensor for linear or angular displacement has a housing (11) with a relatively sliding element carrying an optical grating scale (32) onto which a light beam provided by a semiconductor laser (35) is directed. The light received from the scale is converted into a corresponding electrical signal via a transducer (36) within the housing. A thermal insulator (41) is inserted between the laser and the scale, for preventing heat generated by the laser from being transmitted to the scale, with a heat sink, for dissipating the generated heat mounted on the outside of the housing. ADVANTAGE - Eliminates measuring inaccuracy due to thermal expansion of scale.