Optical positioning device

摘要

The device has a light source (LQ) arranged such that light from the source is penetrated into a scanning bar (A) at a point of intersection of the bar and a scale (M) to arrive back at the bar. The light is split into different partial beams by diffraction and combined again at optical structures i.e. grating structures, of the bar and the scale. A detector (DET) generates periodic detection signals in response to change in a scanning distance between the bar and the scale, and displacement between the bar and the scale in a specified direction due to interference of the combined beams.