The invention is directed to an apparatus for the electrophotographic production of image patterns on a recording medium, particularly or printer or copier, comprising at least one printing unit to which toner is supplied from a toner reservoir. According to various inventive aspects, the invention is directed to devices for delivering the toner and/or for eliminating the toner in such an apparatus.
When the toner supply in the toner reservoir has just about run out, a signal is produced in a known printer that causes the printer to be arrested or stopped. An operator must then replenish toner from a standardized refilling container into the toner reservoir. After the end of the filling procedure, printing operations can be reassumed. The similar case is true for handling used toner that is collected by a cleaning station in the printer or copier. When a used toner container has reached a high filling level, an operator is informed of this by an alarm signal. The printing operations are interrupted and the full used toner container is replaced with an empty one. The described procedure reduces the availability, economic feasibility and user-friendliness of the printer or, respectively, copier. This is particularly felt given high-performance printers that should print or, respectively, copy optimally free of interruptions in order to achieve their full efficiency.
U.S. Pat. NO. 4,967,234 discloses a copier device whose device covers, for example device doors, are connected to an electrical safety means. When the device doors are opened, the copier device is turned off by this safety means. An opening that is not connected to the safety means is incorporated into the device covering. A toner container with fresh toner can be supplied to the copier device via this opening. The fresh toner is refilled into a container. The toner container emptied in this way is then filled with used toner.
U.S. Pat. No. 5,329,340 discloses an apparatus for the electrophotographic generation of image patterns on a recording medium. The apparatus contains two toner reservoirs. When the first toner reservoir is empty, a switch is made to the second toner reservoir. The used toner that arises is collected in a used toner container. When the used toner container is not available, the used toner is collected in an additionally provided container inside the apparatus or outside the apparatus.
WO-A-95 10074 discloses a color printer with a developing unit. Toner from a toner reservoir is supplied to this developing unit with a delivery conduit and a pump.