Optical encoder and method of fabricating its sensor head

摘要

An optical encoder is constructed by a reflection-type scale 1 and a sensor head 4. The sensor head 4 has an irradiation light source 2 and a sensor board 3, the sensor board 3 has a transparent substrate 30 on which light-receiving areas 5 for outputting displacement signals which have different phase with each other, and index gratings 6 for modulating the scale irradiating light are formed to be alternately arranged. The index gratings 6 are formed of the same material film as metal electrode of the light-receiving areas 5.