Patent ID: 6987609

Claim:
A TIR microscope ( 10 ) comprising a microscope housing ( 18 ), an optics system ( 16 ) at one end of a passage ( 19 ) in said microscope housing ( 18 ), said optics system ( 16 ) comprising at least one lens system which includes at least one lens ( 48 ), said optics system ( 16 ) determining an optical axis ( 54 ) and an aperture of said microscope ( 10 ), at least one observation device ( 14 , 22 ), in particular an eyepiece, at another end of said passage ( 19 ), an illumination device ( 24 ) whose illumination light forms at least one illumination beam ( 44 ) which passes through said lens system, said at least one illumination beam ( 44 ) being actually or virtually focused in the focal plane ( 46 ) facing said at least one observation device ( 14 , 22 ) of said at least one lens system ( 48 ) through which said illumination beam ( 44 ) passes and striking a microscope slide ( 36 ) at a predetermined angle ( 13 ) to the optical axis ( 54 ) which is greater than zero, said angle being in the range of a total reflection angle when said illumination light strikes an interface between an object to be observed and a microscope slide, characterized in that said illumination beam, after emanating from a plane of incidence ( 45 ) which perpendicularly intersects said passage ( 19 ) between a front lens ( 48 ) located closest to the object to be detected of the optics system ( 16 ) and said observation device ( 14 , 22 ), is focused in the focal plane ( 46 ) facing said at least one observation device ( 14 , 22 ) of said optics system ( 16 ), and between said plane of incidence and said lens system substantially extends parallel to and at a distance from the optical axis, said focused illumination beam ( 44 ) being supplied in the plane of incidence ( 45 ) by an optical device which is located in the region of said optics system, which has a cross section in the area of said aperture which is much smaller than the cross section of said aperture and which is displaceable in the radial direction with respect to the optical axis ( 54 ).