Patent ID: 7055972

Claim:
A device for an optical system that comprises an objective ( 1 ) and detector (reticle) ( 7 ) or detector surface(s) ( 7 a ) interacting with said objective via a atop aperture ( 6 a ), characterized in that the objective ( 1 ) and stop aperture ( 6 a ) are decentralized or have a decentralizing function in relation to the detector (the reticle) or the detector surface(s) and have thereby a degree of decentralization that essentially prevents beams ( 8 a ) reflected by the detector (reticle) or detector surface(s) passing back through the stop aperture ( 6 a ), wherein the decentralizing function of the objective ( 1 ) means that only parts of, for example, one half ( 2 a ) of the objective, viewed in cross section through the objective at right angles to the beam path ( 8 ), passes the incoming beam ( 8 ) towards the stop aperture wherein the stop ( 6 ) is set at an angle or the stop aperture ( 6 a ) is arranged to be inclined in relation to the plane of the detector (reticle) or detector surface(s) ( 7 a ) at right angles to the beam path ( 8 ) in order to obtain a more even irradiance on the detector or detector surface(s) in comparison to the case when there has not been any setting at an angle or at an indentation.