Color-neutral brightness adjustment for microscope illumination beam path has filter for compensating red shift in light source spectrum adjusted in dependence on brightness of light source

摘要

The brightness adjustment uses a control device (12), for regulating the power supplied to the electric light source (2) supplying the illumination beam path (8) and a device for compensation of the red shift in the light source spectrum with the reduction in the electrical power, using an optical filter (16) inserted in the illumination beam path. The filter has a transmission characteristic for red light which alters along its surface, with displacement of the filter by an electric motor via the control device, in dependence on the brightness of the light source.