Slit scanner
A slit scanner is a scanner in fluorescence microscopes that illuminates the sample not uniformly (as in a Wide Field Microscope) or point by point (as in a Confocal Microscope) but somewhere in between: a line in space is illuminated and this is used to scan the whole 3D volume.
Because this illumination is somehow a case between the confocal and the widefield ones, the Point Spread Function (PSF) of a slit scanning microscope shares properties of both limiting cases.