Photoelectric measuring head for the contactless scanning of measuring fields on a printing sheet with an air permeable annular disk

摘要

A photoelectric measuring head for the contactless scanning of measurement regions, particularly of measurement fields on a printing sheet resting flat. The measuring head having outlet orifices for compressed air on its underside to generated an air cushion between the measuring head and the printing sheet. A measuring head of this kind, suspended on an air cushion provides for high stability, and the least possible distance from the base. This is achieved in that the outlet orifice for the compressed air are formed from a plate which, by virtue of a microporous structure, is air-permeable.