Siemens Aktiengesellschaft

Reiner Lichti

Klaus Dietrich

Hans Kern

Gunter Rosenstock

Apparatus for monitoring supply of electrically conductive writing fluid in a reservoir for an ink printing device which has three electrodes with one pair of the electrodes mounted in a region of the reservoir which is constantly moistened by the writing fluid and provides a first signal which produces a fluid comparison resistance. An additional electrode together with one of the pair of electrodes produces a signal which indicates the change of resistance as a function of the fluid level of the fluid. A control electronics component receives the first and second signals and supplies an output to a shutoff device. A generator and an inverter which receives an input from the generator supply pulses to two of the electrodes.

Apparatus and circuit for monitoring the ink supply and ink printer

A drive circuit for a piezoelectric transducer in an ink jet printer incorporates a resonant circuit formed of an inductance and a piezoelectric transducer functioning as a capacitance, with the resonant circuit being excited to oscillation by means of current pulses, and with such oscillation being damped by means of a damping circuit, said damping beginning after a time delay relative to the onset of said oscillation.

Drive circuit for piezoelectric transducer in ink jet printers

A circuit for operating recording nozzles in ink mosaic recorders, each nozzle having an associated ink channel cylindrically surrounded by a piezoelectric transducer having a diameter which expands upon the application of a voltage thereto having a polarity which is opposite to the direction of polarization of the transducer and contracts upon the application of a voltage having a polarity in the direction of the transducer polarization, has a charging circuit which connects the transducers in a rest state to a common voltage source having a polarity in the direction of polarization of the transducers so that the transducers assume a state of contracted diameter. The circuit further includes a discharging circuit operated by a control input for each transducer operable for discharging an ink droplet from the nozzles after ink is drawn into the channels by operation of the charging circuit. The charging circuit contains a switching arrangement so that the charging circuit can be interrupted independently of the operation of the discharging circuit.

Circuit for operating recording nozzles

A control circuit for momentarily energizing an electromagnetic coil in a teleprinting device recorder has a pair of switching transistors respectively operated by control pulses having a lag between respective switching times and a control transistor biased by a single operating voltage source. When a first of the switching transistors is switched on a rapid current rise in the coil takes place for immediate and rapid activation of the coil plunger which is followed by a maintenance time during which the first switching transistor is either switched off or is in pulsed operation and also during which the energy stored in the electromagnetic coil serves as the maintenance current source, which is followed by switching on of the second control transistor. By the addition of a diode between the coil and the operating voltage source, a feedback circuit is formed so that after disconnection of the electromagnetic coil, the energy stored in the coil is fed back into the operating currents supply network.

Control circuit for electromagnetically-operated recorders in

A circuit arrangement for the operation of recording nozzles in ink mosaic recording devices employing tubular drive elements, which contain recording fluid, and which comprise electromechanical transducers, in particular piezo-electric transducers, whose diameter, and thus internal volume varies in the presence of different voltage potentials, utilizing an electronic switch for each of the electromechanical transducers, for selectively supplying to the respective electromechanical transducers a first voltage potential, and an electronic switch common to all of said electromechanical transducers for supplying in common a second voltage potential to all of said electronic transducers. The first voltage potential preferably is a potential operative to expand the diameters of the electromechanical transducers, and said second voltage potential preferably is a potential operative to contract the diameters of the electromechanical transducers. Means may also be provided in the supply path of current conducted across the electronic switch supplying the first voltage potential to the electromechanical transducers for limiting such current in an adjustable manner.

Circuit arrangement for the operation of recording nozzles in ink mosaic

An arrangement for recording characters composed of matrix-like rastered character elements by means of a matrix printer to provide varying configurations to the recorded characters, by electrically varying the relationship of the respective character elements with respect to time.

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Germering, Germany

Reiner Lichti