US Patent 7298549 Microscope

A confocal microscope has a specimen holding device for holding a specimen (18). The specimen (18) is illuminated by an illuminating unit (10). An optics unit (12) serves to direct radiation produced by the illuminating unit (10) toward the specimen (18) and to direct the radiation emitted by the specimen toward a detector unit (20). The confocal microscope also comprises an aperture diaphragm (34) that is placed in the beam path in front of the detector unit (20). In addition, a focusing lens (30) is provided in the beam path in front of the aperture diaphragm (34). The focusing lens (30) can be moved in order to adjust the confocal microscope, for example, in order to compensate for thermal stresses.