Apparatus for optoelectronically determining power using a light source being of annular design

摘要

The present invention provides an apparatus for optoelectronically determining power for a moving machine element. The apparatus includes two parallel coding discs which are mounted on the machine element and each have grid lines or light windows distributed over their circumference. A light source is arranged on one side of the coding discs and has an associated light meter on the opposite side of the discs. The light source and the light meter are preferably of an annular design in order to transilluminate all the light windows to a largely uniform degree. A diffusion disc is arranged in the beam path between the light source and the coding discs and a light barrier is mounted outside the region of the light windows. At least one of the light windows on one of the coding discs is formed in the beam path of the light barrier and a translucent endless zone is formed on the other of the parallel coding discs.