Honeywell G.m.b.h.

Paul A Diddens

Richard W Denny

Dean M Peterson

Roger D Erickson

Edward R Bade

Charles J O'Toole, Jr

Robert E Humphrey

Boyce D Braschler

An improvement in electrographic recorders to increase the speed of writing that is possible by utilizing a magnetic member behind the paper and by preventing writing signals to occur until the toner is in such a position that writing is possible.

Electrographic recorder with enhanced writing speed

A gray tone recorder uses a selective variation in a recording stylus duty cycle of an electrostatic recording system which recording stylus continues to write at full voltage using a dry toner electrostatically attracted to a recording paper by an electrostatic charge deposited by the recording stylus. The full voltage recording operation produces a high degree of consistency in the gray level density while the duty cycle variation is effective to vary the separation between record segments by producing variable length segments within fixed recording time periods to achieve a gray scale record. The toner is subsequently fixed or bonded to the paper to create a permanent record. Input data codes are compared with a sequence of fixed codes during a writing time period to determine the cut-off point of each write cycle. The system is adaptable for a plural stylii write head by supplying individual stylus write data during each write cycle.

Gray tone recorder

A multistylus recorder uses a recording head having a plurality of side-by-side styli extending across the width of a recording medium which is driven at right angles to the recording head. The recording styli are individually energized to provide a recording on the recording medium using a digital control system for storing addresses of the recording styli to be energized whereby the recording styli are energized from the lowest to highest stored addresses. The recording system uses a minimum to maximum, min-max, accumulator to configure the digital data obtained from an analog-to-digital (A/D) converter representative of an input signal applied to the A/D converter into a format suitable for energizing the multistylus recording head, i.e., the min-max accumulator accepts and stores the digitized values obtained by sampling an input signal by the A/D converter and a sample and hold circuit to obtain a plurality of samples between recording operations to produce a plurality of outputs for energizing each of the plurality of recording styli. The min-max accumulator stores all of the digitized samples of the input data, selects the minimum and maximum digitized values of the input sample, produces stylus addresses for those values and energizes all of the styli between and including the lowest and highest stylus address received since the preceding recording cycle.

Multistylus recording system

In an improved control circuit for the heating current of a system for developing latent photographic images on a heat developable medium, an incipient loss of tension in the record medium is sensed by detecting high frequency components of the energizing current incident to incipient arcing at the heating electrodes. The resulting signal is utilized to interrupt the flow of current to the heating electrodes, to prevent further arcing and the danger of fire. A time delay feature is incorporated to restore the heating current after a predetermined delay. If the tension in the record medium has not been restored, then the incipient arcing will again cause an interruption of the heating current.

Recorder control circuit for suppressing incipient arcing at the heating

In a control circuit to prevent the overheating of a conductively backed recording medium, a closed loop control circuit is provided wherein heat is provided to the heating electrodes of the circuit by one subcircuit under the control of a speed responsive control subcircuit. A feedback loop to a summing junction in the latter subcircuits is monitored to determine a deviation from virtual zero at that junction. A deviation from such virtual zero at that junction is used to control a shutdown safety circuit.

Fail safe control circuit

A voltage buffering coupling circuit for coupling a ground-referenced control signal to a high voltage biased CRT includes all solid state elements, thereby avoiding the tendency of the arc breakdown characteristic of gaseous voltage regulator tubes. The circuits include temperature compensating elements of opposite thermal coefficient characteristics.

Video coupling system

A power limiting circuit for controlling recording electrode energizing power in an electrographic recorder having a plurality of electrographic recording electrodes has a voltage and current monitor circuit for detecting the changes in voltage and current being supplied to electrographic recording electrodes. The monitor circuit is used to maintain the current and voltage levels at predetermined reference levels by inhibiting the firing of preselected ones of the recording electrodes in a first and a second inhibit mode of operation. In the first inhibit mode, the firing of the even numbered electrodes is inhibited to maintain the predetermined power levels being supplied to the recording electrodes. The inhibiting operation is extended in the second inhibit mode to inhibit the odd numbered electrodes as well as the even numbered electrodes in alternate recording lines for a further limiting of electrode energization power to the recording head.

Recording electrode power limiting circuit for an electrographic recorder

An improved recorder for recording substantially simultaneously across the width of a relatively wide sheet of electrosensitive material has a fixed head made up of a laminar stack of recording styli or, as referred to herein, recording pins. Adjacent pins are offset from one another a distance sufficient to allow the passage of a purging fluid therethrough. The purging fluid conveniently may be supplied from a source of low pressure air.

Electrostatic recorder having a fixed head made up of a laminated stack

A trace locator for identifying in a visual display the position on a recording medium of a recorded trace representing an input signal in a multi-trace recorder. The trace position may be displayed without a movement of the recording medium to enable the possible trace to be located and positioned by observing the visual display. The visual display is sequentially advanced by successive clock signals until a predetermined amplitude of an input signal to be displayed is reached. The trace location is displayed for a preset period of time after which the display is cleared prior to a subsequent display of the trace location for either the same input signal or another input signal.

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Denver, CO, United States of America

Paul A Diddens