The Mead Corporation

Suresh C Paranjpe

James W Davis

Frederic L Clark

Robert J Scranton

Burton W Scott

Roger D Wells

John A Robertson

Richard Sutera

John W Donahue

Svetislav Mitrovich

Thomas W Bobick

Eugene Nodov

James E Burnett

Biswa N Ganguly

David W Smith

Robert B McJohnson

Henry N Kannapell

James A Frey

Arthur Cox

Jack D Ames

John E Dobson

Elias Spyrou

Orville A Kaffenberger, Jr

Gary D Cason

Francis P Gunter

Daniel W Moore

A method and apparatus for flattening curled ones of a plurality of moving paper sheets subsequent to the printing and at least partial drying thereof is disclosed. The sheets are transported sequentially along a transport path, and the selected sheets are heated to a plasticizing temperature. The selected sheets are then stretched in both a longitudinal and a lateral direction with respect to the transport direction of the sheets.

Sheet flattening method

The intersheet gaps or spacings between successive sheets of copy paper for an ink jet printing system are set according to the print densities for sheets to be printed to enhance the operation of a sheet dryer within the printing system. The greater the print density, the greater the intersheet gaps such that sheets which are more heavily printed are effectively exclusively within the sheet dryer for a longer period of time and, hence, receive more of the available sheet dryer energy. The print densities are determined from image data which define images to be printed on the sheets by translating the data into the number of drops to be printed per image data word and accumulating the number of drops required to print each sheet by counting the resulting numbers of drops.

Drop counter printer control system

An ink jet printer transporting a print receiving medium angularly past a print head which generates a row of jet drop streams. Drops in the streams are selectively charged to either a print charge level or a catch charge level, and are subsequentlysubjected to a cyclically varying electric deflection field, normal to the row, which deflects of the drops carrying the print charge level into selected print trajectories. A static electric deflection field then separates the drops into print and catch trajectories, with the drops in the catch trajectories being intercepted by a catcher and thereby prevented from striking the print receiving medium. Drops from each jet drop stream may be deflected in a direction perpendicular to the row by the secondary field so as to be deposited at a number of positions on the print receiving medium.

Ink jet printer with secondary, cyclically varying deflection field

An ink jet printer control circuit is disclosed in which provision is made for production of drop clock signal pulses for application to the electromechanical drop stimulation transducer of the printer. Print enable pulses are provided by a state controller means to the charge electrode driver of the printer so as to permit selective charging of drops produced by the jet drop stream. An edge detector means is responsive to the leading edge of each pulse in the drop clock signal pulse train to provide an edge detection pulse. Additionally, an encoder arrangement provides a train of synchronization pulses, each such pulse signifying an increment of movement of the print receiving medium. The state controller responds to the edge detection pulses and to the synchronization pulses and provides a print enable pulse upon receipt of an edge detection pulse next following receipt of a synchronization pulse. The state controller means includes three flip-flops which are sequentially actuated so that a print enable pulse is provided only after receipt of at least two edge detection pulses prior to each synchronization pulse.

Ink jet printer control circuit and method

An ink drop duplicating system employs a plurality of angularly extending ink drop print heads to reproduce an original document. Each printing head produces a row of drop streams which are individually controlled to deposit printing drops at a plurality of printing positions along a line extending perpendicular to the major axis of the printing head. Printing control information for the ink drop printing heads is generated by a photosensing array which extends across one major dimension of an original document and which is scanned across the other major dimension. Scanning data is stored on a magnetic disk. After one or more original documents have been completely scanned, the scanning data is read from the magnetic disk and reorganized to produce drop control signals for the ink drop printing heads.

Ink drop duplicating system

An ink drop printing system for use as part of a duplicator. Sheets which are to be printed by the printing system are fed from one or another of two separate paper supplies and delivered along downwardly converging delivery paths toward a common reception point on a printing transport. The printing transport carries the sheets along a printing path which is angled upwardly and folded back from the delivery paths toward the common reception point. While the sheets are carried upwardly by the printing transport, they are printed by a plurality of inclined, angularly extending, and cooperatively operated jet drop printing heads.

Ink drop printing system

An ink jet printer includes a print head means which generates two parallel rows of jet drop streams. Charge electrodes are mounted on a pair of charge electrode plates which are movable into and out of drop charging positions. A pair of catchers each define a drop catching surface and a drop ingesting slot along the lower edge of the drop catching surface. Each of the catchers is generally pivotally mounted for rotation about an axis parallel to the rows of jet drop streams. The catchers may be pivoted from a drop catching position, in which the drop catching surfaces are substantially parallel, to a full catch position in which drop catching surfaces are inclined to face upward and intercept the jet drop streams. In the full catch position, the drop ingesting slots are positioned closely together. A linkage arrangement is provided for pivoting the catchers from the full catch position to the drop catch position after start up of the print head means. The linkage arrangement also moves the charge electrode plates into the drop charging positions after the catchers are pivoted sufficiently to apply a drop deflecting potential to thereto, but while the drop catching surfaces intercept the jet drop streams.

Ink jet printer

An ink jet printer deposits ink drops from a plurality of jet drop streams along a plurality of parallel adjacent print lines on a sheet of paper. The printer includes a sheet supporting drum, means for rotating the drum, and a print head which is slidably mounted adjacent the drum for linear movement in a direction parallel to the axis of rotation of the drum. A rotatable cam defines a continuous endless camming surface with the cam being driven by a drive arrangement interconnected with the means for rotating the drum. A cam follower means follows the continuous camming surface and moves the print head in a direction parallel to the axis of rotation of the paper supporting drum such that jet streams are directed to deposit drops along respective ones of the print lines during successive rotations of the drum.

Ink jet printer with laterally movable print head

An image scanner for scanning a document along a plurality of scan lines and providing a plurality of print control signal pulses in response to the image density of the document along the scan lines includes a means for projecting a moving document image onto a focal plane and a sensor array positioned in the focal plane. The sensor array includes columns of sensors extending parallel to the direction of image movement and a shift register associated with each column for sensors for shifting electrical outputs from the sensors in the direction of image movement. In a line copy mode of operation, the electrical outputs are shifted at the same rate at the rate of movement of the image such that the given pixel on the image is scanned sequentially by each of the sensors in a column. The electrical outputs are compared with a predetermined reference label to produce a print control signal. In a gray scale mode of operation, the outputs from all of the sensors in a sensor column are accumulated to produce an output related to the average image density of the area scanned by the column of sensors. The electrical outputs resulting from successively scanning overlapping image areas are integrated until a predetermined reference level is reached to produce a print control signal.

Moving image scanner

A jet drop copying apparatus has a print head which directs a row of jets toward a print sheet mounted on a rotating drum. The row of jets extend substantially across the full width of the print sheet and are operated under control of a printing controller to print a series of tracks extending circumferentially along the sheet. The jets are shifted laterally in synchronism with the drum rotation such that each jet is moved a distance equal to the width of one printing track during one rotation of the drum. The shifting continues until a solid print has been obtained. An illumination device is provided for illuminating a narrow strip extending across a document to be copied and projecting an image of the illuminated strip upon a row of photodetectors. Longitudinal image scanning proceeds in synchronism with the rotation of the printing drum, and there is a lateral shifting of the image in synchronism with the shifting of the jet printing tracks.

Apparatus and method for jet drop copying with an array of jets and

A jet drop printer for selectively depositing drops along a plurality of parallel lines on a moving print receiving medium includes a print head for generating a plurality of jet drop streams directed toward the moving print receiving medium, with the streams arranged in a row substantially perpendicular to the direction of movement of the print receiving medium. A drop charging electrode arrangement, adjacent each of the jet drop streams, selectively charges drops in each of the streams to one of a plurality of discrete charge levels. A deflection means provides a plurality of static drop deflecting electrostatic fields, with each of the jet drop streams passing through an associated one of the fields. Each drop deflecting field deflects charged drops passing therethrough in a direction which is inclined with respect to the row of jet drop streams and with respect to the direction of movement of the print receiving medium. Each drop in the jet drop streams is deflected by a distance dependent upon the charge carried by the drop. A drop catcher means positioned adjacent the row of drop streams and extending substantially parallel thereto, catches drops from each of the drop streams which are sufficiently deflected. The deflection means may include a plurality of parallel lateral deflection electrodes for providing first static electrical deflection fields extending substantially parallel to the row of jet drop streams and a longitudinal deflection electrode for providing a second static electrical deflection field extending substantially perpendicular to the row of jet drop streams. Alternatively, the deflection means may comprise a plurality of pairs of parallel deflection electrodes extending obliquely with respect to the row of jet drop streams.

Jet drop printer

An ink jet printer utilizes a substantially electrically conductive deflection electrode which extends generally parallel to at least one row of ink jet drop streams and has a d.c. electrical deflection potential impressed thereon to produce a static electrical deflection field through which drops in the drop streams pass. The deflection electrode is heated by passing a resistive heating current through the electrode and is held by a spring mounting arrangement to compensate for resulting thermal expansion of the electrode, thus maintaining the electrode in tension, such that it is held substantially straight.

Ink jet printer with heated deflection electrode

Ink jet printer startup and shutdown procedure

An ink jet printer produces high resolution printing from continuously flowing, non-stimulated jets. The jets are produced from a common manifold by rows of staggered orifices, all being relatively small in diameter. Drop deflection is accomplished by laminated electrode assemblies which are activated at a lower frequency than the natural drop formation frequency, so that each printed spot on the printing substrate is covered with a fairly large number of relatively small drops.

Jet printer and electrode assembly therefor

An ink jet printer for printing a print image on a print medium selectively deposits ink drops at a plurality of print positions on the medium with each print position defining a print line on the medium extending in the direction of relative movement of the medium. A means for generating a plurality of drop jets directs the jet toward the print medium. A means is provided for selectively deflecting drops from each drop jet to print positions in an associated group of the plurality of print positions. At least two of the print positions in each group of print positions define print lines which substantially overlap the print lines defined by print positions in adjacent groups of print positions.

Growing community of inventors

Xenia, OH, United States of America

Suresh C Paranjpe