Measurement device directs beam to measurement scale and receives reflections of beam to produce phase shifted interference signals which are then evaluated

摘要

A radiation source (4) directs a beam to a measurement scale (8). The beam is reflected from a diffraction grating of the measurement scale into the waveguides (12,18) of a waveguide coupler (10) that outputs phase shifted interference signals which are detected by photodiodes (30,32,34) and analyzed by an evaluation unit. An independent claim is also included for a miniaturized optical scanning head.