Abstract: Process and apparatus for minimizing residual charges in the shift registers of a CCD type scanning array in an asynchronously operated image input terminal in which the unknown arrival time of the next integration signal is predicted and, based on that prediction, the last periodic dumping pulse before the integration signal is delayed a required period of time to assure clearing of residual charges from the shift registers.

Abstract: A constant power regulator for a xerographic fuser in which power control is achieved by taking the sum of the load voltage and current. The regulator includes an operational amplifier connected as a voltage adding circuit. The operational circuit amplifier of the power regulator adds the voltage drop across the fuser and a reference resistor connected in series with the fuser and the voltage drop across the fixed reference resistance which represents the current flow through the fuser. The output of this summing circuit is detected by a photodetector that electrically isolates the power regulator from a voltage regulator which has an output for controlling the power supply to the fuser through, for example, a triac, controlled as a function of the power supply signal and the detected voltage generated by the power regulating circuit.

Abstract: In an electrostatographic copying system, where a common imaging surface is subjected to currents from several corona generators during copying, the actual output current of each corona generator is individually measured, and controlled, utilizing individual current measurement resistive paths between the low voltage sides of discrete power supply circuits provided for each corona generator and a common ground path from the imaging surface, and by individually feeding back the shield current of each corona generator in a feedback path separate from the current measurement path. A.C. lead feedback, and switching and measurement circuitry are also disclosed.

Abstract: In a copier with a copying platen, and platen cover unit pivotal thereover, which may comprise a document feeder, the platen cover unit having connecting pivotal lifting means, and a magnetic latch for magnetically latching the platen cover unit in a closed position closely overlying the copier platen with a magnetic flux field between the platen cover unit and the copier generated by at least one magnet on one completing a magnetic circuit through at least one magnetic flux conductive member on the other when the magnetic latch is closed, the magnetic latching of the platen cover unit in the closed position providing for document retention and illumination thereunder and magnetic resistance to opening of the platen cover unit by the lifting means, and with a switch for indicating closure of the platen cover unit, the improvement wherein the switch comprises a magnetic switch magnetically coupled to the magnetic latch, the magnetic switch being magnetically actuated in response to the change in magnetic flux