Projector type-coder for handling data has three-fold grating mounted on transparent substrate with antireflection layers, adjacent to movable plate with grating and photosensors

摘要

The coder has a transparent substrate (71) with first and second antireflection films (711,712) on its flat top and bottom surfaces. The coding or scaling grating (6) is mounted on an antireflection film (72) on top of the first film. Light can shine through the gaps in the grating. The grating and its substrate adheres to a metallic or aluminized baseplate (100) with a flat surface (101). There is an antireflection film (73) between the surface of the baseplate and the second film.