Photoelectric angle measuring device with adjacent order interference

摘要

A photoelectric measuring device for measuring the position of two objects which can be rotated relative to each other. The measuring device includes a grid graduation located on a graduation support to which the first object can be attached. The second object is attached to a scanning unit scan that scans the grid by means of light diffraction. A beam from the light source is diffracted into partial beam bundles in a first graduation zone of the grid graduation and brought into interference in a second graduation zone which is diametrically opposite of the first graduation zone on the grid graduation for measurement. In order to eliminate or compensate for eccentricity and to produce signals that are phase-displaced and interfere with sinusoidal intensity changes between interference fringes, only partial beam bundles of adjacent orders of diffraction are brought into interference in the second graduation zone.