Photoelectric encoder, scale and method of manufacturing scale

摘要

A photoelectric encoder includes: a scale having a grating formed thereon along a measuring axis; a light source operative to emit light to the scale so as to form a light spot on the grating; and a photoreceiver operative to receive reflected light from the scale. The light source and the photoreceiver are disposed so as to be allowed to move relative to the scale at least in a direction along the measuring axis. The light source emits the light to the scale so that the photoreceiver receives the reflected light by the scale. The light source emits light with different wavelengths. The scale includes a plurality of reflection portions that respectively reflect the light with different wavelengths.