Abstract: The invention relates to a toner replenishment system for a dry toner developer unit in a photocopier. Toner is introduced into the developer unit in a canister which is closed at one end and has near its other end an extractor plate mounted for rotation around the axis of the canister and for axial movement along the canister, the toner powder being disposed between the closed end and the extractor plate. This canister can be simply loaded into a developer unit and then, during operation of the developer unit, toner demand is met at a metered rate by rotation of the extractor plate causing an extractor blade to slice toner and transfer it through the extractor plate to the axially outer side thereof for subsequent conveyance to the developer hopper.

Abstract: In a document copier in which forward and reverse travel of a scanning member, preferably a document-carrying carriage moving past a stationary scanning source, is driven in a forward direction by a first drive chain, and entrained for movement in a reverse direction by a second, more rapidly circulating drive chain. The second drive chain is effective also to drive the image-developer unit and the sheet feed system of the copier. In the preferred embodiment, the first drive member is synchronized to circulate at the same speed as the peripheral speed of rotation of the photoconductor drum.

Abstract: A radiant heat fuser for an electrostatic copying machine in which heat for fusing the delicate toner image on top of a sheet is applied using a top heater of radiant type, and background heat to the underside of the sheet is provided by means of heat-absorbing and -radiating elements positioned in the fuser bed and arranged to absorb radiant heat while no sheet is being fed and to radiate and convect heat to the underside of the sheet as it passes through the fuser. The control of the temperature of these heat-absorbing and -radiating elements is achieved by way of a cooling air system throttled in accordance with temperature-responsive deformation of the heat-absorbing and -radiating elements some of which are accordingly of bimetallic form.