U.S. Philips Corporation

Hans D Hinz

Herbert Lobl

Ulf Rothgordt

A large number of printing electrodes are combined to form groups which each time have a common switching point, each printing electrode of the same ordinal number of each group being connected to a common voltage amplifier. A capacitor (C) is connected between the common switching point (G) of a group and the electrical control element (SK) associated with each printing electrode (BE). All capacitors are simultaneously charged, however, consecutively one group after the other, to the analog voltages which correspond to the information to be printed and which are present on the relevant voltage amplifiers (V). The time required for the charging of all capacitors (C) is less than the printing time for an image element. The circuit arrangement is particularly suitable for an electrophoretic printing method.

Circuit arrangement for controlling a large number of printing

The invention relates to a printing device for electrophoretic recording by means of electrodes which are relatively movable with respect to an image carrier. Between the image carrier and electrodes, a liquid developer fluid is present in which the electrodes are immersed. Recording takes place under the influence of a control voltage (U.sub.ST) causing adherence of electrophoretic pigment to the image carrier. In order to enable point-like (matrix-like) recording, the surface of the image carrier is electrically conductive and the developer fluid at the area of the electrodes is continuously exchanged to maintain the electrophoretic pigment supply.

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Tornesch, Germany

Hans D Hinz