Device for regulating the pupil illumination and intensity in microscope e.g. for mask inspection has optical component which is available for injection and extraction of condenser from beam path

摘要

Device has a part of illuminating radiation which is shielded for the measurement of measuring beam path. An optical component is available for the injection and extraction of condenser from the beam path and illuminating lens is arranged after the adjustable operative diaphragm or aperture diaphragm. Blocked-out part of illuminating radiation leads over a bertrand lens of detector. Measured value is evaluated by the controller. Illumination control is regulated and monitored from the measuring result and it is for the monitoring and modification of diaphragm centering as well as for the supervision and regulation of focus position. An independent claim is also included for the method for regulating the pupil illumination and intensity in microscope e.g. for mask inspection.