Patent Document ID: 20070147821
Application ID: 11644524
Patent Status: 0

Claim One:
1. A device for optically inspecting an investigated section of a specularly or diffusely reflecting surface having at least one light source for providing bright-field illumination that is imaged onto the investigated section employing a telecentric beam path, an electronic camera having a lens that receives part of the light coming from within the investigated section of the surface via a telecentric beam path and transmits the images obtained to a processor, and an electronic controller for controlling the illumination of the investigated section and the operation of the camera, characterized in that the camera-and-illuminator-side beam path has an aspherical field lens whose focal length is less than twice the maximum dimension of the investigated section, and whose projection on the surface to be investigated at least just barely covers the investigated section, where the investigated section is imaged onto the entrance pupil of the lens of the camera by a beamsplitter arranged at an angle of about 45° to the optical axis of the field lens and a light source, other than a point source, whose minimum dimension in the focal plane of the field lens substantially equals twice to ten-times the diameter of the entrance pupil of the lens of the camera is arranged in the focal plane, which is penetrated by the optical axis of the field lens.