US3673600A - Electrographic recording method and apparatus - Google Patents

Electrographic recording method and apparatus Download PDF

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US3673600A
US3673600A US862369A US3673600DA US3673600A US 3673600 A US3673600 A US 3673600A US 862369 A US862369 A US 862369A US 3673600D A US3673600D A US 3673600DA US 3673600 A US3673600 A US 3673600A
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recording medium
dielectric
developer
recording
ramp
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David E Damouth
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Xerox Corp
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Xerox Corp
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/24—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 whereby at least two steps are performed simultaneously
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/34—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner
    • G03G15/344—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner by selectively transferring the powder to the recording medium, e.g. by using a LED array
    • G03G15/348—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the powder image is formed directly on the recording material, e.g. by using a liquid toner by selectively transferring the powder to the recording medium, e.g. by using a LED array using a stylus or a multi-styli array
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
    • G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
    • G06K15/14—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by electrographic printing, e.g. xerography; by magnetographic printing

Definitions

  • ABSTRACT I Electrographic recording apparatus in which the latent electrostatic charge patterns recorded on a dielectric recording medium are rendered visible substantially coextensive with the deposition of the charge patterns on the recording medium.
  • the recording medium is transported in a generally vertical direction at the charging zone.
  • the array of charging electrodes are disposed from the record medium at the charging zone at a negative inclination relative to horizontal to form a ramp comprising a portion of the developer system.
  • a second ramp is disposed from the recording medium at the charging zone at a positive inclination relative to horizontal, comprising another portion of the developer system.
  • the positively inclined ramp is further situated .in a manner such that developer material will be transported down the ramp in substantially uniform quantities to contact the recording medium. As the developer material contacts the recording medium, toner from the developer material will be attracted to the latent electrostatic charge patterns to render the charge patterns visible. Unused portions of the developer material after contacting the record medium are then transported down the ramp formed by the electrode array to a developer reservoir.
  • This invention relates generally to electrographic recording and more particularly, to electrographic recording in a manner which permits immediate viewing of the recorded information.
  • a pattern of electrostatic charges is placed on a suitable dielectric support material in a configuration corresponding to the desired information record.
  • This pattern of electrostatic charges may be applied directly to the recording surface by an electrographic recording stylus, an electrode array, or any of the other known electrographic recording means.
  • the charge pattern is developed or toned by a suitable developer material containing a toner which may comprise a pigmented thermoplastic resin.
  • the toner material which adheres to the dielectric support member may be fused to the support to form a permanent copy of the information.
  • the process of electrographic recording in some aspects is similar to the now well known xerographic process. That is, in both processes patterns of electrostatic charges are created which correspond to the desired information record. In the process of xerography, this is accomplished by blanket charging of a photoconductive insulator, and then selectively discharging portions thereof by exposure to light, generally through a suitable optical system.
  • the process of electrographic recording differs from the process of xerography in that the charge pattern in electrographic recording is created without the use of photosensitive materials. That is, the process of xerography requires the use of a suitable photoconductor, whereas the process of electrographic recording does not.
  • images are formed by means of small conductive electrodes of styli which are utilized to apply a charge pattemin image configuration to a suitable dielectric recording medium.
  • a suitably high voltage or potential is applied across the dielectric recording medium to produce a latent residual charge pattern of information on the recording medium.
  • the electrodes or styli may be disposed in a linear array across the recording medium in contact therewith or in close proximity thereto.
  • the styli or electrodes may be disposed in two or more closely spaced linear arrays with the individual electrodes in the next adjacent linear array being displaced therefrom to result in an overlap of adjacent charge patterns on the recording medium.
  • a suitable electrical signal may then be utilized to control the voltage or potential applied to the various styli at any point in time representative of the particular information to be recorded.
  • a charge pattern is formed in or on the recording surface by either ionization of the intervening air or direct conductive transfer, producing an electrostatic charge pattern on the recording surface.
  • the charge transfer thereof is usually by air ionization rather than by conductive transfer.
  • the electrostatic charge pattern formed on the surface of the recording medium may then be developed with a developer material which may comprise a suitable carrier and a finely divided electroscopic toner material, bearing a charge of opposite polarity to the electrostatic charge pattern, whereby the toner material is attracted to and deposited on the record medium according to the charge pattern.
  • the resulting visible image may then be made permanent if desired, by passing the recording medium, in the case of a paper recording medium, through a heated area wherein the toner material is fused to the surface of the recording medium.
  • the powder developed image may be transferred to other suitable support material and thereafter fused thereto to form a pennanent image.
  • the recording surface may be passed through a suitable viewing area to permit viewing of the recorded information and subsequently passed through a cleaning station to remove the powder and electrostatic charge pattern therefrom, thereby permitting reuse of the recording medium.
  • the latent electrostatic images When employing the electrographic recording process, it is advantageous to develop the latent electrostatic images in point of time as soon after they are produced as possible.
  • One reason for developing such images as soon after they are produced as possible is due to the fact that depending on the quality of the dielectric, the charge patterns produced on the recording medium will decay with time and as a function of ambient conditions. As a result, if the charge patterns are to be developed at a point in time extensively subsequent to the formation thereof, the remaining electrostatic image on the recording medium may be at a relatively low level, hence detracting from the quality of the developed image.
  • the record medium is transported in a generally vertical direction at the charging zone.
  • the array of charging electrodes are disposed from the record medium at the charging zone at a negative inclination relative to horizontal to form a ramp comprising a portion of the developer system.
  • a second ramp is disposed from the record medium at the charging zone at a positive inclination relative to horizontal, comprising another portion of the developer system.
  • the positively inclined ramp is further situated in a manner such that developer material will be transported down the ramp in substantially uniform quantities to contact the recording medium As the developer material contacts the recording medium, toner from the developer material will be attracted to the latent electrostatic charge patterns to render the charge patterns visible.
  • Unused portions of the developer material after contacting the record medium are then transported down the ramp formed by the electrode array to a developer reservoir.
  • the development zone may be substantially coextensive with the charging zone thereby permitting rapid viewing of the recorded information.
  • FIG. 1 is a simplified schematic illustration of an electrographic recording apparatus as contemplated by the present invention.
  • FIG. 2 is a simplified schematic illustration of the electrographic charging elements adapted for use in the embodiment of FIG. 1.
  • FIG. 1 of the drawings there is illustrated an electrographic recording apparatus as contemplated by the present invention which includes an outer casing 11, the upper portion of which includes a viewing area 12 and a slot 13 through which the final copy of the recorded information may be withdrawn, as hereinafter more fully described.
  • the recording medium which may comprise a continuous web of dielectrically coated paper 21 is supported on a supply roll 14 within casing 11 and is withdrawn therefrom by means of a web drive mechanism 19.
  • the web 21 is withdrawn from supply roll 14 in a generally horizontal direction, passing over platen roller 16 whereat the directional path of travel of web 21 is extended in a generally vertical direction. From platen roller 16, web 21 passes through viewing area 12 supported by heated platen 18, to the paper drive mechanism 19 and out exit slot 13.
  • Supply roll 14 is supported from the base of casing 11 by means of a pair of support brackets 36, one at either end thereof, and is rotatably journaled therebetween on shaft 37.
  • a braking member is provided to exert a constant braking force against supply roll 14 to prevent overrunning of supply roll 14 as a result of inertial mementum.
  • Platen roller 16 is journaled for rotation between the side portions of casing 11 on shaft 38. Platen roller 16 is the preferred arrangement is freely rotatable under the influence of web 21. However, it should be understood that a suitable drive mechanism may also be provided to impart rotational movement to platen roller 16. Platen roller 16 is formed from an electrically conductive material to which an electrical potential may be applied the purpose of which will hereinafter be more fully explained.
  • Heated platen 18 includes a smooth heat conductive surface within the general viewing area 12 against which the web 21 is supported.
  • the heat conductive surface of platen 18 is maintained at a substantially uniform temperature during machine operation to fuse toner material on web 21 to the surface of web 21.
  • Heat may be supplied to heated platen 18 by means of electrical resistance heating elements adjacent to or embedded within platen 18. As power is supplied to the heating elements heat will be transferred to the heat conductive surface of platen 18. Suitable power controls may also be provided to regulate the amount of heat at the conductive surface of platen 18 to insure against over heating of web 21 yet at the same time maintaining an elevated temperature sufficient to fuse the toner material to web 21.
  • Web drive mechanism 19 includes a pair of pinch rollers 39 and 40 rotatably journaled between the sides of casing 11 which form a bite or nip therebetween to engage web 21.
  • the surface of pinch rollers 39 and 40 may be covered with a resilient material having a high coefficient of friction to enhance the web advancement characteristics thereof.
  • a source of motive power operatively connected to pinch rollers 39 and 40 is also operatively connected to the recording logic to advance web 21 in accordance with the recorded information.
  • An override mechanism is also provided between pinch rollers 39 and 40 and the source of motive power to allow web 21 to be manually withdrawn from slot 13.
  • the directional path of travel of web 21 about platen roller 16 extends in a general vertical direction.
  • An electrode array generally designated 22 is utilized to selectively charge the dielectric web 21 in an information configuration at the recording station 15 in response to predetermined electrical signals.
  • the electrode array 22 comprises a plurality of small conductive electrodes or styli 23 each one of which is operatively connected by suitable conducting members to an electronic pulsing circuit (not shown).
  • a suitably high electrical potential may thus be applied to selected ones of the individual styli or conducting elements 23 in response to electrical information signals.
  • a suitable electrical potential is also provided on platen roller 16.
  • the potential applied to platen roller 16 may be maintained at a substantially continuous level independent of the selected pulsing of the individual conducting elements 23 and may be of either a positive or negative polarity. However, it has been found that where a positive polarity is applied to styli 23 a negative polarity potential applied to platen roller 16 produces good charging of dielectric web 21 and permits operation at generally lower overall voltage levels.
  • the styli or conductive elements 23 are embedded between upper and lower layers of a dielectric material insulating the individual elements from each other and externally thereabout. At one end, however, the conductive elements 23 are exposed for contact or substantial contact at least with the dielectric web 21.
  • the electrode array 22 and conductive elements 23 may be conveniently produced from copper-clad plastic sheets of a type which are generally employed for making printed electronic circuits, with the desired array of conductive elements 23 being provided by photoetching of the copper layer.
  • the copper layer may then be coated with a thin uniform dielectric layer which insulates the conducting elements 23.
  • the dielectric layer also provides a continuous planar surface whereby the electrode array can function as a portion of the developer system as will hereinafter be more fully described.
  • the electrode array 22 is positioned at the recording station in a manner to provide an inclined planar surface with the exposed tips of conductive elements 23 being substantially in contact with the dielectric web at the recording station. From the recording station, the planar surface is disposed at a negative inclination relative to horizontal to form a ramp or chute comprising a portion of the developer system.
  • a second ramp or chute 34 is disposed from the dielectric web 21 at the recording zone at a positive inclination relative to horizontal.
  • the lower end of ramp 34 is positionedonly slightly above and in close proximity to the electrodes 23 in electrode array 22 where the electrodes contact web 21.
  • ramp 34 and electrode array 22 are limited largely only by the particle size of the developer material and ramp 34 is as wide as the web 21 and electrode array 22.
  • ramp 34 is provided with a guide or gate 35 which is coextensive with the width of ramp 34 and is spaced from the upper surface thereof a distance such that the carrier is released from the gate in a thin substantially uniform layer.
  • a developer sump or reservoir 31 is supported inwardly of casing 11 in communication with the ramp formed by the planar surface of electrode array 22. Sump 31 is partially filled with a developer material which is to be utilized in rendering latent charge patterns on dielectric web 21 visible.
  • the developer material in sump 31 may comprise a pigmented thermoplastic resin intermixed with a suitable carrier material as is well known in the art.
  • a conveyor member generally designated 32 is supported within casing 11 in communication with sump 31 and ramp 34 to transport developer material from sump 31 and discharge the transported developer material onto ramp 34.
  • Conveyor 32 according to the preferred arrangement includes a flexible endless member 29 having a plurality of reservoirs or buckets 27 spaced along the surface thereof to engage quantities of the developer material.
  • Endless member 29 is entrained about a first roller or pulley member 30 which is joumaled for rotation within sump 31 and a second roller or pulley member 28 which is joumaled for rotation adjacent ramp 34.
  • Conveyor member 29 is driven about roller members 28 and 30 by means of'drive mechanism 33 to transport developer material from sump 31 onto ramp 34.
  • Means may also be provided for automatically adding toner material to the developer material in sump 31 to replace the toner material depleted from the system through the development process.
  • the viewing area 12 is positioned on the portion of the easing 1 1 which is immediately adjacent the end of the ramp 34 in the direction of advance of the dielectric web 21 whereby the image on web 21 is viewable substantially coextensively with the deposition of charge patterns on the web 21.
  • the web 21 is advanced from the supply roll 14 by the paper drive mechanism 19 over the platen roller 16, past the viewing area 12 and the heated platen 18 and out the exit slot 13 in casing 11.
  • the individual conductive elements 23 are selectively activated by input information to generate latent images of the appropriate information on the web 21.
  • Developer in the sump 31 is lifted out of the sump 31 by the conveyor 32 and is deposited on the upper portion of the downwardly inclined ramp 34.
  • the developer rolls or slides down the ramp 34 to the gate 35 whereat it is released from the gate 35 in a thin substantially uniform layer.
  • the developer thus released from the gate 35 rolls or slides down the ramp 34, to contact the web 21.
  • information recorded on web 21 is viewable through the viewing area 12 substantially coextensive with the deposition of charge on web 21 and the viewer or user has immediate access to the recorded information.
  • an endless flexible belt or cylindrical member may be substituted for the web 21 as described.
  • the latent electrostatic image is then developed, as hereinabove described, directly on the belt or cylinder and the resulting visible image is immediately viewable in the viewing area.
  • the powder image on the belt or cylinder may be transferred to a suitable support, such as paper, as generally known in the art; e.g., electrostatic transfer.
  • the endless belt or cylinder is then passed through a suitable cleaning station to remove toner remaining thereon 7 after transfer and residual charge patterns. If a permanent record of the printed information is not required, the transfer step may be omitted and the belt or cylinder passed through a cleaning station immediately after the viewing area.
  • a bias potential may be employed to control background and image density with the bias potential being applied either between the ramp 34 and the platen 16 or on additional electrodes placed near the point at which developer contacts the recording medium for development.
  • the application of a bias potential for control of background and/or image density is generally known in the art and therefore no detailed explanation thereof is deemed necessary for a full understanding of the invention.
  • a screen may be interposed between the web 21 and the lower portion of the ramp 34, whereby the carrier material bounces off the screen onto the electrode array 22 and only toner passes through the screen to contact the web 21. 1n such a modification, the screen may be biased to control image density and background.
  • the ramp may be modified in numerous ways to enhance the rolling or sliding of the carrier material down the ramp 34.
  • the ramp 34 may be continuously vibrated to enhance flow characteristics.
  • the electrographic recording as contemplated by the present invention is particularly advantageous in that developing is effected very close to the electrode array whereby there is a very short distance and time between production of the latent electrostatic image and development thereof. Therefore, a user may immediately view the printed information.
  • Electrographic recording apparatus comprising,
  • an array of electrically conductive members for selectively depositing electrostatic charge in information configuration onto said recording medium, said array including a generally planar surface disposed at an inclination from said recording medium at said recording station to form a first ramp along which developer material is transported from the recording station,
  • a second member having a generally planar surface thereon disposed at an inclination to said recording medium at said recording station to form a second ramp along which developer material is transported to contact said recording medium at the recording station, and
  • Electrographic recording apparatus comprising;
  • a casing including a viewing area
  • a movable dielectric recording medium positioned in the casing, a portion of said movable dielectric recording medium being viewable through said viewing area;
  • first ramp means positioned in the casing for returning unused portions of developer material, said first ramp means including electrically conductive means for selectively depositing electrostatic charge in information configuration onto said recording medium;
  • a second ramp means positioned in the casing for transporting and releasing developer material onto the recording medium at a point which is both immediately adjacent the point at which a portion of the dielectric recording medium is viewable through the viewing area and coextensive with the point at which the electrostatic charge is deposited on the recording medium;
  • the first ramp means comprises upper and lower layers of a dielectric material, the upper layer having a planar surface for returning the developer, said electrically conducting means comprising a plurality of individual electrically conducting elements embedded in the upper and lower layers of the dielectric material to insulate the elements, one end of said individual elements being exposed and in close proximity with said recording medium for depositing the electrostatic charge on said recording medium.
  • Electrographic recording apparatus comprising;
  • a casing including a viewing area
  • a ramp means within the casing positively inclined with respect to horizontal, the lower end of said ramp means positioned adjacent the dielectric recording medium at a point during the movement thereof immediately prior to the point at which said dielectric recording medium is visible in the viewing area to deposit developer on the recording medium;
  • an array of charging electrodes means for depositing electrostatic charge in information configuration on said recording medium at a point on the moving recording medium immediately prior to the point at which developer is deposited thereon, said array including an insulated planar surface at a negative inclination with respect to the horizontal, the upper end of said insulated planar surface positioned adjacent to and spaced immediately below the lower end of the ramp means and defining a surface for returning developer;
  • the recording medium is a continuous web of dielectrically coated paper and further comprising a roller means rotatably supported within the casing, said paper web passing over said roller means in a generally vertical direction, the ramp means and electrode array being positioned adjacent said paper web as the paper web passes over said roller means in the generally vertical direction.
  • the ramp means includes a guide means for releasing the developer in a substantially uniform layer.
  • a method of recording information on a dielectric recording medium comprising:
  • a method of recording information on a dielectric recording medium comprising:
  • Electrographic recording apparatus comprising:
  • a dielectric recording medium including means for depositing electrostatic charges in information configuration on said dielectric recording medium; means for advancing the dielectric recording medium, said means for advancing the dielectric recording medium moving the dielectric recording medium past the recording station; means positioned at the recording station for rendering the charge patterns on said dielectric recording medium visible substantially simultaneously with deposition of charge in information configuration on the dielectric recording medium; and
  • said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an operator substantially coextensive with the development thereof.
  • Electrographic recording apparatus comprising:
  • a dielectric recording medium a dielectric recording medium
  • a recording station including recording means for depositing electrostatic charges in information configuration on said dielectric recording medium, said recording means defining a ramp adjacent being transported away from the recording station on said ramp.
  • said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an perator substantially coextensive with the development thereof.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)

Abstract

Electrographic recording apparatus in which the latent electrostatic charge patterns recorded on a dielectric recording medium are rendered visible substantially coextensive with the deposition of the charge patterns on the recording medium. The recording medium is transported in a generally vertical direction at the charging zone. The array of charging electrodes are disposed from the record medium at the charging zone at a negative inclination relative to horizontal to form a ramp comprising a portion of the developer system. A second ramp is disposed from the recording medium at the charging zone at a positive inclination relative to horizontal, comprising another portion of the developer system. The positively inclined ramp is further situated in a manner such that developer material will be transported down the ramp in substantially uniform quantities to contact the recording medium. As the developer material contacts the recording medium, toner from the developer material will be attracted to the latent electrostatic charge patterns to render the charge patterns visible. Unused portions of the developer material after contacting the record medium are then transported down the ramp formed by the electrode array to a developer reservoir. By thus utilizing the electrode array as a portion of the overall developer path the development zone may be substantially coextensive with the charging zone thereby permitting rapid viewing of the recorded information.

Description

United States Patent Damouth June 27, 1972 [54] ELECTROGRAPHIC RECORDING METHOD AND APPARATUS [72] lnventor: David E. Damouth, Penfield, N.Y.
Xerox Corporation, Rochester, NY.
Sept. 30, 1969 [73] Assignee:
[22] Filed:
,[21] App]. No.: 862,369
3,263,234 7/1966 Epsteinw. ...346/74 ES 3,348,521; 10/1967 Hawk.... .118/637 X 2,932,690 4/1960 Adams 178/66 A 3,082,970 3/1963 Rasmussen ..346/76 Primary Examiner-Howard W. Britton Aztorney-Marn & Jangarathis, James J. Ralabate, John E. Beck and Benjamin B. Sklar [57] ABSTRACT I Electrographic recording apparatus in which the latent electrostatic charge patterns recorded on a dielectric recording medium are rendered visible substantially coextensive with the deposition of the charge patterns on the recording medium. The recording medium is transported in a generally vertical direction at the charging zone. The array of charging electrodes are disposed from the record medium at the charging zone at a negative inclination relative to horizontal to form a ramp comprising a portion of the developer system. A second ramp is disposed from the recording medium at the charging zone at a positive inclination relative to horizontal, comprising another portion of the developer system. The positively inclined ramp is further situated .in a manner such that developer material will be transported down the ramp in substantially uniform quantities to contact the recording medium. As the developer material contacts the recording medium, toner from the developer material will be attracted to the latent electrostatic charge patterns to render the charge patterns visible. Unused portions of the developer material after contacting the record medium are then transported down the ramp formed by the electrode array to a developer reservoir. By thus utilizing the electrode array as a portion of the overall developer path the development zone may be substantially coextensive with the charging zone thereby permitting rapid viewing of the recorded infonnation.
15 Claims, 2 Drawing Figures PATENTEnJum m2 3, 673,600
saw 1 or 2 vFig. l.
INVENTOR.
David E. Domouth BY ATTORNEYS PATENTEDJUNZ'! me I 3, 73, 00
sum 2 nr .2
x J A DOVid E. o m
ATTORNEYS ELECTROGRAPHIC RECORDING METHOD AND APPARATUS BACKGROUND OF THE. INVENTION This invention relates generally to electrographic recording and more particularly, to electrographic recording in a manner which permits immediate viewing of the recorded information.
In the art of electrographic recording, a pattern of electrostatic charges is placed on a suitable dielectric support material in a configuration corresponding to the desired information record. This pattern of electrostatic charges may be applied directly to the recording surface by an electrographic recording stylus, an electrode array, or any of the other known electrographic recording means. Subsequently, the charge pattern is developed or toned by a suitable developer material containing a toner which may comprise a pigmented thermoplastic resin. Subsequent to the development process, the toner material which adheres to the dielectric support member may be fused to the support to form a permanent copy of the information.
The process of electrographic recording in some aspects is similar to the now well known xerographic process. That is, in both processes patterns of electrostatic charges are created which correspond to the desired information record. In the process of xerography, this is accomplished by blanket charging of a photoconductive insulator, and then selectively discharging portions thereof by exposure to light, generally through a suitable optical system. However, the process of electrographic recording differs from the process of xerography in that the charge pattern in electrographic recording is created without the use of photosensitive materials. That is, the process of xerography requires the use of a suitable photoconductor, whereas the process of electrographic recording does not.
In one form ofelectrographic recording, images are formed by means of small conductive electrodes of styli which are utilized to apply a charge pattemin image configuration to a suitable dielectric recording medium. As the recording medium is transversed relative to the styli or electrodes, one suitable medium being for example, a continuous web of paper stock, a suitably high voltage or potential is applied across the dielectric recording medium to produce a latent residual charge pattern of information on the recording medium. The electrodes or styli may be disposed in a linear array across the recording medium in contact therewith or in close proximity thereto. Alternatively, the styli or electrodes may be disposed in two or more closely spaced linear arrays with the individual electrodes in the next adjacent linear array being displaced therefrom to result in an overlap of adjacent charge patterns on the recording medium.
ln operation, a suitable electrical signal may then be utilized to control the voltage or potential applied to the various styli at any point in time representative of the particular information to be recorded. As the high potential pulses are thus selectively applied to the individual electrodes or styli, a charge pattern is formed in or on the recording surface by either ionization of the intervening air or direct conductive transfer, producing an electrostatic charge pattern on the recording surface. It should be noted, that for most materials, even though the electrodes are in contact with the recording surface, the microscopic roughness of the recording media surface results in an intervening air layer over most of the contact area. As a result, the charge transfer thereof is usually by air ionization rather than by conductive transfer. Thus, for example, if any applicably high voltage is applied to the styli by an electronic drive circuit, a residual voltage proportionate to the applied voltage level will remain on the surface of the dielectric, the residual voltage, however, decaying with time and as a function of ambient conditions.
The electrostatic charge pattern formed on the surface of the recording medium may then be developed with a developer material which may comprise a suitable carrier and a finely divided electroscopic toner material, bearing a charge of opposite polarity to the electrostatic charge pattern, whereby the toner material is attracted to and deposited on the record medium according to the charge pattern. The resulting visible image may then be made permanent if desired, by passing the recording medium, in the case of a paper recording medium, through a heated area wherein the toner material is fused to the surface of the recording medium. Alternatively, the powder developed image may be transferred to other suitable support material and thereafter fused thereto to form a pennanent image. In the' case where a permanent image may not be required, the recording surface may be passed through a suitable viewing area to permit viewing of the recorded information and subsequently passed through a cleaning station to remove the powder and electrostatic charge pattern therefrom, thereby permitting reuse of the recording medium.
When employing the electrographic recording process, it is advantageous to develop the latent electrostatic images in point of time as soon after they are produced as possible. One reason for developing such images as soon after they are produced as possible is due to the fact that depending on the quality of the dielectric, the charge patterns produced on the recording medium will decay with time and as a function of ambient conditions. As a result, if the charge patterns are to be developed at a point in time extensively subsequent to the formation thereof, the remaining electrostatic image on the recording medium may be at a relatively low level, hence detracting from the quality of the developed image.
Of primary concern in many applications is the extreme desirability to provide immediateviewing of the recorded information immediately following the recording on the record medium. Because the undeveloped charge patterns are not visible, it is therefore extremely desirable to develop these images immediately after formation so that they may be checked or verified. In many applications such as electrostatic typewriters, computer output printers, communications printers and the like immediate viewing of the alphanumeric or general graphic information is absolutely essential. However, with the use of present development techniques this capability is not possible. This is due in large part to the fact that present development techniques utilized in conjunction with the electrographic recording process have been derived from the development techniques generally employed in the development of xerographically formed latent electrostatic images. However, the requirement that the electrostatically formed latent image be visualized immediately after the formation thereof has not been a problem presented in conjunction with the xerographic process as is now required in conjunction with the electrographic recording process.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide improved development apparatus for rendering latent electrostatic images visible.
It is another object of the patent invention to efiect development of latent electrostatic charge patterns visible, substantially coextensive with the formation of the charge patterns on a record medium.
It is yet a further object of the present invention to electrographically form latent electrostatic charge patterns on a recording medium with an electrode array which comprises a portion of a developer system by which the latent electrostatic charge patterns are rendered visible, substantially coextensive with deposition of the charge patterns on the record medium.
These and other object of the invention are attained from a unique structural configuration of an array of charging members and development apparatus in an electrographic recording apparatus in which development of the latent electrostatic images occurs substantially simultaneously or coextensively with a deposition of charge patterns on the record media.
According to one embodiment of the invention, the record medium is transported in a generally vertical direction at the charging zone. The array of charging electrodes are disposed from the record medium at the charging zone at a negative inclination relative to horizontal to form a ramp comprising a portion of the developer system. A second ramp is disposed from the record medium at the charging zone at a positive inclination relative to horizontal, comprising another portion of the developer system. The positively inclined ramp is further situated in a manner such that developer material will be transported down the ramp in substantially uniform quantities to contact the recording medium As the developer material contacts the recording medium, toner from the developer material will be attracted to the latent electrostatic charge patterns to render the charge patterns visible. Unused portions of the developer material after contacting the record medium are then transported down the ramp formed by the electrode array to a developer reservoir. By thus utilizing the electrode array as a portion of the overall developer path the development zone may be substantially coextensive with the charging zone thereby permitting rapid viewing of the recorded information.
Other objects of the invention will become readily apparent to those skilled in the art in view of the following detailed disclosure and description thereof, especially when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified schematic illustration of an electrographic recording apparatus as contemplated by the present invention.
FIG. 2 is a simplified schematic illustration of the electrographic charging elements adapted for use in the embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 of the drawings, there is illustrated an electrographic recording apparatus as contemplated by the present invention which includes an outer casing 11, the upper portion of which includes a viewing area 12 and a slot 13 through which the final copy of the recorded information may be withdrawn, as hereinafter more fully described. The recording medium which may comprise a continuous web of dielectrically coated paper 21 is supported on a supply roll 14 within casing 11 and is withdrawn therefrom by means of a web drive mechanism 19. As may be seen from FIG. 1, the web 21 is withdrawn from supply roll 14 in a generally horizontal direction, passing over platen roller 16 whereat the directional path of travel of web 21 is extended in a generally vertical direction. From platen roller 16, web 21 passes through viewing area 12 supported by heated platen 18, to the paper drive mechanism 19 and out exit slot 13.
Supply roll 14 is supported from the base of casing 11 by means of a pair of support brackets 36, one at either end thereof, and is rotatably journaled therebetween on shaft 37. In the preferred arrangement a braking member is provided to exert a constant braking force against supply roll 14 to prevent overrunning of supply roll 14 as a result of inertial mementum.
Platen roller 16 is journaled for rotation between the side portions of casing 11 on shaft 38. Platen roller 16 is the preferred arrangement is freely rotatable under the influence of web 21. However, it should be understood that a suitable drive mechanism may also be provided to impart rotational movement to platen roller 16. Platen roller 16 is formed from an electrically conductive material to which an electrical potential may be applied the purpose of which will hereinafter be more fully explained.
Heated platen 18 includes a smooth heat conductive surface within the general viewing area 12 against which the web 21 is supported. The heat conductive surface of platen 18 is maintained at a substantially uniform temperature during machine operation to fuse toner material on web 21 to the surface of web 21. Heat may be supplied to heated platen 18 by means of electrical resistance heating elements adjacent to or embedded within platen 18. As power is supplied to the heating elements heat will be transferred to the heat conductive surface of platen 18. Suitable power controls may also be provided to regulate the amount of heat at the conductive surface of platen 18 to insure against over heating of web 21 yet at the same time maintaining an elevated temperature sufficient to fuse the toner material to web 21.
Web drive mechanism 19 according to the preferred arrangement includes a pair of pinch rollers 39 and 40 rotatably journaled between the sides of casing 11 which form a bite or nip therebetween to engage web 21. The surface of pinch rollers 39 and 40 may be covered with a resilient material having a high coefficient of friction to enhance the web advancement characteristics thereof. A source of motive power operatively connected to pinch rollers 39 and 40 is also operatively connected to the recording logic to advance web 21 in accordance with the recorded information. An override mechanism is also provided between pinch rollers 39 and 40 and the source of motive power to allow web 21 to be manually withdrawn from slot 13.
At the recording station which has been generally designated as 15 in the drawings, the directional path of travel of web 21 about platen roller 16 extends in a general vertical direction. An electrode array generally designated 22 is utilized to selectively charge the dielectric web 21 in an information configuration at the recording station 15 in response to predetermined electrical signals. According to a preferred embodiment the electrode array 22 comprises a plurality of small conductive electrodes or styli 23 each one of which is operatively connected by suitable conducting members to an electronic pulsing circuit (not shown). A suitably high electrical potential may thus be applied to selected ones of the individual styli or conducting elements 23 in response to electrical information signals. A suitable electrical potential is also provided on platen roller 16. The potential applied to platen roller 16 may be maintained at a substantially continuous level independent of the selected pulsing of the individual conducting elements 23 and may be of either a positive or negative polarity. However, it has been found that where a positive polarity is applied to styli 23 a negative polarity potential applied to platen roller 16 produces good charging of dielectric web 21 and permits operation at generally lower overall voltage levels.
As may be seen more clearly from FIG. 2, the styli or conductive elements 23 are embedded between upper and lower layers of a dielectric material insulating the individual elements from each other and externally thereabout. At one end, however, the conductive elements 23 are exposed for contact or substantial contact at least with the dielectric web 21. The electrode array 22 and conductive elements 23 may be conveniently produced from copper-clad plastic sheets of a type which are generally employed for making printed electronic circuits, with the desired array of conductive elements 23 being provided by photoetching of the copper layer. The copper layer may then be coated with a thin uniform dielectric layer which insulates the conducting elements 23. The dielectric layer also provides a continuous planar surface whereby the electrode array can function as a portion of the developer system as will hereinafter be more fully described.
The electrode array 22 is positioned at the recording station in a manner to provide an inclined planar surface with the exposed tips of conductive elements 23 being substantially in contact with the dielectric web at the recording station. From the recording station, the planar surface is disposed at a negative inclination relative to horizontal to form a ramp or chute comprising a portion of the developer system.
A second ramp or chute 34 is disposed from the dielectric web 21 at the recording zone at a positive inclination relative to horizontal. The lower end of ramp 34 is positionedonly slightly above and in close proximity to the electrodes 23 in electrode array 22 where the electrodes contact web 21. The
spacing between ramp 34 and electrode array 22 is limited largely only by the particle size of the developer material and ramp 34 is as wide as the web 21 and electrode array 22. The
upper portion of ramp 34 is provided with a guide or gate 35 which is coextensive with the width of ramp 34 and is spaced from the upper surface thereof a distance such that the carrier is released from the gate in a thin substantially uniform layer.
A developer sump or reservoir 31 is supported inwardly of casing 11 in communication with the ramp formed by the planar surface of electrode array 22. Sump 31 is partially filled with a developer material which is to be utilized in rendering latent charge patterns on dielectric web 21 visible. The developer material in sump 31 may comprise a pigmented thermoplastic resin intermixed with a suitable carrier material as is well known in the art. A conveyor member generally designated 32 is supported within casing 11 in communication with sump 31 and ramp 34 to transport developer material from sump 31 and discharge the transported developer material onto ramp 34. Conveyor 32 according to the preferred arrangement includes a flexible endless member 29 having a plurality of reservoirs or buckets 27 spaced along the surface thereof to engage quantities of the developer material. Endless member 29 is entrained about a first roller or pulley member 30 which is joumaled for rotation within sump 31 and a second roller or pulley member 28 which is joumaled for rotation adjacent ramp 34. Conveyor member 29 is driven about roller members 28 and 30 by means of'drive mechanism 33 to transport developer material from sump 31 onto ramp 34. Means may also be provided for automatically adding toner material to the developer material in sump 31 to replace the toner material depleted from the system through the development process.
The viewing area 12 is positioned on the portion of the easing 1 1 which is immediately adjacent the end of the ramp 34 in the direction of advance of the dielectric web 21 whereby the image on web 21 is viewable substantially coextensively with the deposition of charge patterns on the web 21.
In operation, the web 21 is advanced from the supply roll 14 by the paper drive mechanism 19 over the platen roller 16, past the viewing area 12 and the heated platen 18 and out the exit slot 13 in casing 11. As the paper web is thus advanced, the individual conductive elements 23 are selectively activated by input information to generate latent images of the appropriate information on the web 21.
Developer in the sump 31 is lifted out of the sump 31 by the conveyor 32 and is deposited on the upper portion of the downwardly inclined ramp 34. The developer rolls or slides down the ramp 34 to the gate 35 whereat it is released from the gate 35 in a thin substantially uniform layer. The developer thus released from the gate 35 rolls or slides down the ramp 34, to contact the web 21.
As the developer material flowing from ramp 34 contacts the web 21 toner from the developer mixture is electrostatically attracted to the charge patterns on web 21 to render the charge patterns visible. As has been previously pointed out, the charge patterns are thus rendered visible at immediately subsequent to the deposition of charge on the web 21 which is in point of time substantially coextensive with deposition of charge on web 21. After contact with web 21, unused portions of the flowing developer are returned to the developer sump 31 via the ramp comprising the smooth planar surface overlying styli or electrode elements 23.
As a result of the uniquely configured combination of the electrode array and developer system, information recorded on web 21 is viewable through the viewing area 12 substantially coextensive with the deposition of charge on web 21 and the viewer or user has immediate access to the recorded information.
The hereinabove described embodiment of the invention may be modified in numerous ways within the spirit and scope of the invention. Thus, for example, an endless flexible belt or cylindrical member may be substituted for the web 21 as described. In such case, the latent electrostatic image is then developed, as hereinabove described, directly on the belt or cylinder and the resulting visible image is immediately viewable in the viewing area. If a permanent record of the recorded information is desired, the powder image on the belt or cylinder may be transferred to a suitable support, such as paper, as generally known in the art; e.g., electrostatic transfer. The endless belt or cylinder is then passed through a suitable cleaning station to remove toner remaining thereon 7 after transfer and residual charge patterns. If a permanent record of the printed information is not required, the transfer step may be omitted and the belt or cylinder passed through a cleaning station immediately after the viewing area.
As another modification, a bias potential may be employed to control background and image density with the bias potential being applied either between the ramp 34 and the platen 16 or on additional electrodes placed near the point at which developer contacts the recording medium for development. The application of a bias potential for control of background and/or image density is generally known in the art and therefore no detailed explanation thereof is deemed necessary for a full understanding of the invention.
As a further modification, a screen may be interposed between the web 21 and the lower portion of the ramp 34, whereby the carrier material bounces off the screen onto the electrode array 22 and only toner passes through the screen to contact the web 21. 1n such a modification, the screen may be biased to control image density and background.
As still other modifications, the ramp may be modified in numerous ways to enhance the rolling or sliding of the carrier material down the ramp 34. For example, the ramp 34 may be continuously vibrated to enhance flow characteristics.
These and other modifications should be apparent to those skilled in the art from the teachings herein.
The electrographic recording as contemplated by the present invention is particularly advantageous in that developing is effected very close to the electrode array whereby there is a very short distance and time between production of the latent electrostatic image and development thereof. Therefore, a user may immediately view the printed information.
Numerous modifications and variations of the invention are possible in light of the above teachings and therefore the invention may be practiced other than as particularly described.
What is claimed is:
1. Electrographic recording apparatus comprising,
means for advancing a dielectric recording medium "onto which information is to be recorded past a recording station,
an array of electrically conductive members for selectively depositing electrostatic charge in information configuration onto said recording medium, said array including a generally planar surface disposed at an inclination from said recording medium at said recording station to form a first ramp along which developer material is transported from the recording station,
a second member having a generally planar surface thereon disposed at an inclination to said recording medium at said recording station to form a second ramp along which developer material is transported to contact said recording medium at the recording station, and
means for depositing developer material onto said second ramp to generate a flow of developer material along said second ramp and into contact with said recording medium and said first recited ramp at said recording station to render patterns of charge on said recording medium visible substantially coextensive with the deposition of charge on said recording medium, the unused portions of flowing developer material being transported from the recording station along said first recited ramp.
2. Electrographic recording apparatus comprising;
a casing, including a viewing area;
a movable dielectric recording medium positioned in the casing, a portion of said movable dielectric recording medium being viewable through said viewing area;
a first ramp means positioned in the casing for returning unused portions of developer material, said first ramp means including electrically conductive means for selectively depositing electrostatic charge in information configuration onto said recording medium;
a second ramp means positioned in the casing for transporting and releasing developer material onto the recording medium at a point which is both immediately adjacent the point at which a portion of the dielectric recording medium is viewable through the viewing area and coextensive with the point at which the electrostatic charge is deposited on the recording medium;
means for depositing developer material onto the second ramp means to generate flow along said second ramp meanS whereby developer is released from the second ramp means onto the recording medium and unused developer is deposited on the first ramp means, thereby rendering the recorded information visible and viewable substantially simultaneously with the recording thereof.
3. The recording apparatus as defined in claim 2 wherein the second ramp meanS includes a guide means to release the developer in a substantially uniform layer.
4. The recording apparatus as defined in claim 3 wherein the first ramp means comprises upper and lower layers of a dielectric material, the upper layer having a planar surface for returning the developer, said electrically conducting means comprising a plurality of individual electrically conducting elements embedded in the upper and lower layers of the dielectric material to insulate the elements, one end of said individual elements being exposed and in close proximity with said recording medium for depositing the electrostatic charge on said recording medium.
5. Electrographic recording apparatus comprising;
a casing including a viewing area;
a dielectric recording medium positioned in the casing;
means for moving said dielectric recording medium said moving including a point where the recording medium is viewable in the viewing area;
a ramp means within the casing positively inclined with respect to horizontal, the lower end of said ramp means positioned adjacent the dielectric recording medium at a point during the movement thereof immediately prior to the point at which said dielectric recording medium is visible in the viewing area to deposit developer on the recording medium;
an array of charging electrodes means for depositing electrostatic charge in information configuration on said recording medium at a point on the moving recording medium immediately prior to the point at which developer is deposited thereon, said array including an insulated planar surface at a negative inclination with respect to the horizontal, the upper end of said insulated planar surface positioned adjacent to and spaced immediately below the lower end of the ramp means and defining a surface for returning developer;
a developer reservoir positioned in said casing below the lower end of the insulated planar surface; and
means for conveying developer from the reservoir to the upper portion of the ramp means whereby developer flows down said ramp means and contacts said recording medium to render charge patterns on said recording medium visible and the unused developer is deposited on the planar surface and transported to the developer reservoir, whereby the recorded information is rendered visible and viewable substantially simultaneously with the recording thereof.
6. The apparatus as defined in claim 5 wherein the recording medium is a continuous web of dielectrically coated paper and further comprising a roller means rotatably supported within the casing, said paper web passing over said roller means in a generally vertical direction, the ramp means and electrode array being positioned adjacent said paper web as the paper web passes over said roller means in the generally vertical direction.
7. The apparatus as defined in claim 6 wherein the ramp means includes a guide means for releasing the developer in a substantially uniform layer.
8. A method of recording information on a dielectric recording medium comprising:
passing a dielectric recording medium onto which information is to be recorded past a recording station;
depositing electrostatic charge patterns in information configuration on said dielectric recording medium at said recording station;
rendering charge patterns on said dielectric recording medium visible substantially coextensive with deposition of charge on the recording medium by contacting said recording medium with a developer material at said recording station; and
subsequently passing the dielectric recording medium past an operator viewing station immediately adjacent said recording station, whereby said visible charge patterns are viewable by an operator substantially coextensive with the development thereof.
9. The method as defined in claim 8 wherein said charge patterns are rendered visible by passing from a developer storage zone a developer material comprised of toner and carrier over the dielectric recording medium substantially coextensive with deposition of charge on the recording medium.
10. A method of recording information on a dielectric recording medium, comprising:
depositing at a recording station by an electrographic recording means electrostatic charges, in information configuration, on a moving dielectric recording medium;
rendering charge patterns on the dielectric recording medium visible substantially simultaneously with the formation thereof by passing from a developer storage zone a developer material over the dielectric recording medium in close proximity to the point at which the electrostatic pattern is placed on the dielectric recording medium;
depositing unused portions of developer material onto the electrographic recording means; and
returning unused portions of developer material on the electrographic recording means to the developer storage zone.
11. The method as defined in claim 10 and further comprising: subsequently passing the dielectric recording medium past an operator viewing station immediately adjacent said recording station, whereby said visible charge patterns are viewable by an operator substantially coextensive with the development thereof.
12. The method as defined in claim 10 wherein the developer material is passed from the developer storage zone over the dielectric recording medium in a thin uniform layer.
13. Electrographic recording apparatus, comprising:
a dielectric recording medium; a recording station including means for depositing electrostatic charges in information configuration on said dielectric recording medium; means for advancing the dielectric recording medium, said means for advancing the dielectric recording medium moving the dielectric recording medium past the recording station; means positioned at the recording station for rendering the charge patterns on said dielectric recording medium visible substantially simultaneously with deposition of charge in information configuration on the dielectric recording medium; and
an operator viewing station closely adjacent to said recording station, said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an operator substantially coextensive with the development thereof.
14. Electrographic recording apparatus, comprising:
a dielectric recording medium; a recording station including recording means for depositing electrostatic charges in information configuration on said dielectric recording medium, said recording means defining a ramp adjacent being transported away from the recording station on said ramp. 15. The apparatus as defined in claim 14 and further comprising:
an operator viewing station closely adjacent to said recording station, said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an perator substantially coextensive with the development thereof.

Claims (14)

  1. 2. Electrographic recording apparatus comprising; a casing, including a viewing area; a movable dielectric recording medium positioned in the casing, a portion of said movable dielectric recording medium being viewable through said viewing area; a first ramp means positioned in the casing for returning unused portions of developer material, said first ramp means including electrically conductive means for selectively depositing electrostatic charge in information configuration onto said recording medium; a second ramp means positioned in the casing for transporting and releasing developer material onto the recording medium at a point which is both immediately adjacent the point at which a portion of the dielectric recording medium is viewable through the viewing area and coextensive with the point at which the electrostatic charge is deposited on the recording medium; means for depositing developer material onto the second ramp means to generate flow along said second ramp meanS whereby developer is released from the second ramp means onto the recording medium and unused developer is deposited on the first ramp means, thereby rendering the recorded information visible and viewable substantially simultaneously with the recording thereof.
  2. 3. The recording apparatus as defined in claim 2 wherein the second ramp meanS includes a guide means to release the developer in a substantially uniform layer.
  3. 4. The recording apparatus as defined in claim 3 wherein the first ramp means comprises upper and lower layers of a dielectric material, the upper layer having a planar surface for returning the developer, said electrically conducting means comprising a plurality of individual electrically conducting elements embedded in the upper and lower layers of the dielectric material to insulate the elements, one end of said individual elements being exposed and in close proximity with said recording medium for depositing the electrostatic charge on said recording medium.
  4. 5. Electrographic recording apparatus comprising; a casing including a viewing area; a dielectric recording medium positioned in the casing; means for moving said dielectric recording medium said moving including a point where the recording medium is viewable in the viewing area; a ramp means within the casing positively inclined with respect to horizontal, the lower end of said ramp means positioned adjacent the dielectric recording medium at a point during the movement thereof immediately prior to the point at which said dielectric recording medium is visible in the viewing area to deposit developer on the recording medium; an array of charging electrodes means for depositing electrostatic charge in information configuration on said recording medium at a point on the moving recording medium immediately prior to the point at which developer is deposited thereon, said array including an insulated planar surface at a negative inclination with respect to the horizontal, the upper end of said insulated planar surface positioned adjacent to and spaced immediately below the lower end of the ramp means and defining a surface for returning developer; a developer reservoir positioned in said casing below the lower end of the insulated planar surface; and means for conveying developer from the reservoir to the upper portion of the ramp means whereby developer flows down said ramp means and contacts said recording medium to render charge patterns on said recording medium visible and the unused developer is deposited on the planar surface and transported to the developer reservoir, whereby the recorded information is rendered visible and viewable substantially simultaneously with the recording thereof.
  5. 6. The apparatus as defined in claim 5 wherein the recording medium is a continuous web of dielectrically coated paper and further comprising a roller means rotatably supported within the casing, said paper web passing over said roller means in a generally vertical direction, the ramp means and electrode array being positioned adjacent said paper web as the paper web passes over said roller means in the generally vertical direction.
  6. 7. The apparatus as defined in claim 6 wherein the ramp means includes a guide means for releasing the developer in a substantially uniform layer.
  7. 8. A method of recording information on a dielectric recording medium comprising: passing a dielectric recording medium onto which information is to be recorded past a recording station; depositing electrostatic charge patterns in information configuration on said dielectric recording medium at said recording station; rendering charge patterns on said dielectric recording medium visible substantially coextensive with deposition of charge on the recording medium by contacting said recording medium with a developer material at said recording station; and subsequently passing the dielectric recording medium past an operator viewing station immediately adjacent said recording station, whereby said visible charge patterns are viewable by an operator substantially coextensive with the development thereof.
  8. 9. The method as defined in claim 8 wherein said charge patterns are rendered visible by passing from a developer storage zone a developer material comprised of toner and carrier over the dielectric recording medium substantially coextensive with deposition of charge on the recording medium.
  9. 10. A method of recording information on a dielectric recording medium, comprising: depositing at a recording station by an electrographic recording means electrostatic charges, in information configuration, on a moving dielectric recording medium; rendering charge patterns on the dielectric recording medium visible substantially simultaneously with the formation thereof by passing from a developer storage zone a developer material over the dielectric recording medium in close proximity to the point at which the electrostatic pattern is placed on the dielectric recording medium; depositing unused portions of developer material onto the electrographic recording means; and returning unused portions of developer material on the electrographic recording means to the developer storage zone.
  10. 11. The method as defined in claim 10 and further comprising: subsequently passing the dielectric recording medium past an operator viewing station immediately adjacent said recording station, whereby said visible charge patterns are viewable by an operator substantially coextensive with the development thereof.
  11. 12. The method as defined in claim 10 wherein the developer material is passed from the developer storage zone over the dielectric recording medium in a thin uniform layer.
  12. 13. Electrographic recording apparatus, comprising: a dielectric recording medium; a recording station including means for depositing electrostatic charges in information configuration on said dielectric recording medium; means for advancing the dielectric recording medium, said means for advancing the dielectric recording medium moving the dielectric recording medium past the recording station; means positioned at the recording station for rendering the charge patterns on said dielectric recording medium visible substantially simultaneously with deposition of charge in information configuration on the dielectric recording medium; and an operator viewing station closely adjacent to said recording station, said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an operator substantially coextensive with the development thereof.
  13. 14. Electrographic recording apparatus, comprising: a dielectric recording medium; a recording station including recording means for depositing electrostatic charges in information configuration on said dielectric recording medium, said recording means defining a ramp adjacent the dielectric recording medium for transporting unused developer material away from said recording station; means for advancing the dielectric recording medium, said means for advancing the dielectric recording medium moving the dielectric recording medium past the recording station; and means positioned at the recording station for releasing developer material adjacent the dielectric recording medium at a point immediately adjacent the means for depositing electrostatic charges in information configuration to thereby render the charge patterns on said dielectric recording medium visible substantially simultaneously with deposition of charge in information configuration, the unused developer material being transported away from the recording station on said ramp.
  14. 15. The apparatus as defined in claim 14 and further comprising: an operator viewing station closely adjacent to said recording station, said means for advancing the dielectric recording medium moving the dielectric recording medium past the viewing station immediately after the charge patterns are rendered visible whereby said charge patterns are viewable by an perator substantially coextensive with the development thereof.
US862369A 1969-09-30 1969-09-30 Electrographic recording method and apparatus Expired - Lifetime US3673600A (en)

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US3797457A (en) * 1970-03-06 1974-03-19 R Bushnell Coating of surfaces with powder
US3948218A (en) * 1973-11-30 1976-04-06 Agfa-Gevaert, A.G. Electrostatic copier device
US3971042A (en) * 1970-02-25 1976-07-20 Xerox Corporation Writing apparatus having wear resistant material
US4042939A (en) * 1975-09-12 1977-08-16 Xerox Corporation Printer/plotter style system for confined installation and method
US5208613A (en) * 1991-03-04 1993-05-04 Canon Kabushiki Kaisha Image forming apparatus
US6467605B1 (en) 1971-04-16 2002-10-22 Texas Instruments Incorporated Process of manufacturing

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US2890922A (en) * 1956-03-29 1959-06-16 Standard Register Co Apparatus for reproducing electrical information
US2932690A (en) * 1956-09-21 1960-04-12 Addressograph Multigraph Apparatus for image reproduction
US3082970A (en) * 1962-05-08 1963-03-26 Burdick Corp Electrocardiograph
US3263234A (en) * 1961-10-04 1966-07-26 Burroughs Corp Apparatus and method of electrostatic recording
US3348521A (en) * 1962-08-28 1967-10-24 Xerox Corp Automatic toner control system

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US2890922A (en) * 1956-03-29 1959-06-16 Standard Register Co Apparatus for reproducing electrical information
US2932690A (en) * 1956-09-21 1960-04-12 Addressograph Multigraph Apparatus for image reproduction
US3263234A (en) * 1961-10-04 1966-07-26 Burroughs Corp Apparatus and method of electrostatic recording
US3082970A (en) * 1962-05-08 1963-03-26 Burdick Corp Electrocardiograph
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Publication number Priority date Publication date Assignee Title
US3971042A (en) * 1970-02-25 1976-07-20 Xerox Corporation Writing apparatus having wear resistant material
US3797457A (en) * 1970-03-06 1974-03-19 R Bushnell Coating of surfaces with powder
US6467605B1 (en) 1971-04-16 2002-10-22 Texas Instruments Incorporated Process of manufacturing
US3948218A (en) * 1973-11-30 1976-04-06 Agfa-Gevaert, A.G. Electrostatic copier device
US4042939A (en) * 1975-09-12 1977-08-16 Xerox Corporation Printer/plotter style system for confined installation and method
US5208613A (en) * 1991-03-04 1993-05-04 Canon Kabushiki Kaisha Image forming apparatus

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GB1318605A (en) 1973-05-31
DE2047637A1 (en) 1971-06-16

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