Abstract: A system for light splitting particularly suitable for microscopic investtion of living tissues using the so called confocal or tandem scanning by a scanning disk with a number of spirally arranged elementary holes similar to a Nipkow disk. This system for light splitting uses a Koesters reflecting prism having a semi-transparent mirror coating between two parts of said prism. According to this invention this semi-transparent mirror coating is parallel with illuminating pencils of rays striking the prism and with image pencils of rays leaving the prism.

Abstract: An arrangement preventing the creation of secondary images in the case of the so called "tandem scanning" of objects by means of a scanning disk with spirally arranged openings similar to a Nipkow disk and a mirror provided on one of its surfaces with a semitransparent mirror layer in which said mirror has a thickness sufficient to space apart the light rays reflected from the mirrored and unmirrored surfaces so that only the light ray reflected from the mirrored surface will pass through the scanning disk.