Siemens Aktiengesellschaft

Hans Kern

Joachim Heinzl

Erich Kattner

Reiner Lichti

Ulrich Heider

Fritz Giebler

Guetner Rosenstock

A plunger armature printing system incorporates an opto-electronic sensor for sensing the movement of a vane fixed to the armature of the print mechanism. The output signal generated by the sensor is employed to define periods for measurement of the speed of movement of the armature. A microprocessor is employed for supplying accelerating and decelerating pulses to the armature magnet for causing the armature to achieve a preselected printing force, in response to the time intervals between similar signals produced by said sensor, and to return said armature to its rest position rapidly without rebound.

Microprocessor-controlled printing mechanism having an opto-electronic

A speed control circuit for a DC motor has a phase comparator to which is supplied a theoretical frequency, emitted by a clock pulse generator, and an actual frequency, emitted from a pulse transmitter connected to the drive shaft of the motor. A first rotation direction signal, obtained from a rotation direction indicator, and a second rotation direction signal, obtained from the comparator, are combined in a logic element, the output of which is supplied to a drive circuit for driving the DC motor. A reference voltage is also supplied to the drive circuit, the reference voltage being obtained from another output of the comparator and supplied to the drive circuit through a filter. The reference voltage is a DC voltage which is proportional to the amount of phase deviation detected by the comparator. This reference voltage is utilized by the drive circuit to set the proportional value of the current supplied to the DC motor.

Speed control circuit for a DC motor

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

A circuit arrangement for piezo-electric recording nozzles, in ink mosaic recording devices, to effect a temperature regulation of the control voltages therefor in which the respective recording nozzles are each provided with a control circuit for individually controlling the respective nozzles and which may be individually adjusted, in combination with a regulating circuit which is common to all of the control circuits, and includes temperature-dependent means for controlling the regulating means, whereby the latter supplies at its output a voltage which varies in accordance with the environmental temperature at such temperature-dependent means.

Circuit arrangement for temperature-dependent voltage regulation of

A heating device for recording heads of ink mosaic recorders, for maintaining the ink therefrom at an optimum temperature at time of discharge from the head. Means are provided for supplying heat to the head directly at the discharge orifices thereof. The device is further provided with control means, including temperature sensing means, for maintaining the temperature of the ink constant. Means are also provided for preventing operation of the recording head unless the ink is at its nominal operating temperature.

Heating device for recording heads in ink mosaic recorders

A device for monitoring the supply of printing liquid in the reservoir of an ink-operated printer and the like, in which two monitoring electrodes are disposed in and wetted by the printing liquid, with circuit means being connected to the electrodes for monitoring the electrical resistance therebetween, which resistance varies in response to changes in the amount of ink in the reservoir. Means are provided, responsive to predetermined resistance values, for actuating at least one display element, and/or effecting disconnection of an associated printer. Additional circuit means may also be connected to the monitoring means for actuating a preliminary warning device prior to actual triggering of a display element indicating the exhaustion of the printing liquid supply. Means also may be provided for monitoring the supply of a data carrier, i.e. paper, which means may likewise be operatively connected to the display element, whereby the latter serves as a common display element to indicate both the operational status of the ink supply reservoir and the presence of a data carrier for receiving the printing.

Device for monitoring the ink supply in ink-operated printers

A device for monitoring the supply of electrically conductive recording fluid in a supply container for ink recording devices and other recording devices utilizing recording fluid, employing electrodes which are wetted by recording fluid and a circuit arrangement which detects the electrical resistance between the electrodes and triggers a display device when the amount of recording fluid falls below a specific volume, in which a plurality of electrodes are provided within the supply container, two electrodes of which define therebetween a fluid-specific standard resistance, formed by the recording fluid, and two electrodes defined therebetween a resistance, formed by the recording fluid, which changes in dependence upon the level of the fluid, with at least those electrodes which detect the fluid-specific standard resistance being disposed in an area of the supply container which is constantly wetted by fluid.

Device for monitoring the ink supply in ink recording devices

The invention relates to a circuit arrangement for driving a plurality of printing jets in mosaic printers employing a plurality of tubular drive elements of polarized ceramic which hold printing liquid therein and whose diameter may be contracted or expanded by the application of suitably poled voltages thereto, in which activation of a jet takes place by the application of a pulse thereto comprising two half cycles of opposite polarity, the first cycle of which is operative to effect an expansion of the drive element from a normal rest condition, and the second is operative to effect a contraction of the drive element from its normal rest condition.

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Munich, Germany

Hans Kern