Abstract: A digital copying device with an adjustable reproduction characteristic. This characteristic maps optical densities ODin of an original document onto optical densities ODout of a copy that is to be made of the original.

Abstract: A method of forming a multi-color image, comprising image elements in a first color which along at least part of their circumference adjoin image elements of one or more following colors wherein separation images in the first, second, third and any following color are each built up from image dot patterns of colored toner powder. The separation images are transferred to an intermediate support to collect said separate images to form a multi-color image. The multi-color image is then transferred from the intermediate support to an image receiving material. The second and each following generated separation image is generated so that the image elements, which on transfer onto the intermediate support are required to adjoin image elements of a separation image already transferred thereto previously, at least partially overlap said previously transferred image elements.

Abstract: In a contact fixing system in which a heat-softened toner image is fixed onto a sheet material by being pressed against the sheet material in a nip between the peripheral surfaces of two circulating fixing members, such as rollers pressing one against the other or a roller pressing against an image carrying belt, residues of the toner of an image and paper dust are removed from the surface of a fixing member in a cleaning zone beyond the fixing nip by moving in rolling contact with that surface a circulating cleaning surface, such as a roller surface, to which the toner adheres preferentially and which has a multiplicity of spaced-apart perforations formed therein and so disposed that with continued movements of the cleaning surface through the cleaning zone a toner layer formed on the cleaning surface is repeatedly pressed thin and excess toner present in it is displaced to the perforations for discharge through them into a cavity inside the cleaning member.