Device and method for optically sorting bulk material

A device for the optical selection of at least a fraction of components from a bulk material stream conveyed along a conveyance direction, including a camera, with a camera viewing direction oriented on the bulk material stream, a background, situated behind the bulk material stream in the camera viewing direction, having a color adaptable to a color of a selected fraction of the components of the bulk material stream, an analysis and control unit, coupled to the camera, for providing control of a separation unit, the separation unit controlling selection of components from the bulk material stream according to a decision criterion, wherein:

• the camera unit provides local resolution and has at least two color channels each having different spectral sensitivity;
• the background is illuminated by a plurality of illuminants, each illuminant emitting light with a spectral distribution adapted to a spectral sensitivity of the camera;
• and
• the analysis and control unit determines at least one local color value of a component of the bulk material stream transverse to the conveyance direction and regulates setting brightness of the illuminants so that the color of the background assumes the at least one local color value.