Abstract: A disc-stacker for inverting sheets either singly or in sets as they exit a copier enabling dual function N-1 and 1-N sequence copying with either face-up or face-down copies. The stacker comprises a sheet inverter wheel having a slot into which one or more copy sheets to be inverted may be inserted. The sheets are fed into the slots by a pair of feed rolls. A compiler tray is disposed between the feed rolls and the inverter wheel. In the single sheet inversion mode the wheel is rotated each time a sheet is deposited in the slot. The sheet is stripped from the slot by stripping member and falls into a catch tray. The inverter wheel then returns to receive and convey subsequent sheets. In the set inversion mode, the wheel is not rotated until all the sheets of the set have been received in the slot. The compiler tray supports and registers the trail edges of the set of copy sheets before they are inverted.

Abstract: A convenient reflecting material is a ceramic fiber felt in which the container is partially embedded, the felt being bleached by the radiation from the source to form a pure white reflector conforming to the exterior of the container. The ceramic fiber felt is virtually indestructable, and costs only a few pence. The felt can be made sufficiently thick that the reflector acts as a heat insulator so that heat losses to the back of the reflector are low. The time for the system to warm-up is dependent almost entirely on the source and its enclosing tube, as little heat passes into the reflector.