US3623123A - Electrostatic printer - Google Patents

Electrostatic printer Download PDF

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Publication number
US3623123A
US3623123A US806782A US3623123DA US3623123A US 3623123 A US3623123 A US 3623123A US 806782 A US806782 A US 806782A US 3623123D A US3623123D A US 3623123DA US 3623123 A US3623123 A US 3623123A
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United States
Prior art keywords
potential
grid
wires
ions
coupled
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US806782A
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English (en)
Inventor
Alex E Jvirblis
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Singer Co
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Singer Co
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/385—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material
    • B41J2/41—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material for electrostatic printing
    • 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
    • G03G15/32—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 charge pattern is formed dotwise, e.g. by a thermal head
    • G03G15/321—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 charge pattern is formed dotwise, e.g. by a thermal head by charge transfer onto the recording material in accordance with the image
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S101/00—Printing
    • Y10S101/37—Printing employing electrostatic force

Definitions

  • PATENTEDunv 23 can 3.623.123
  • Electrostatic printing is generally accomplished by positioning a suitable receptor between a pair of electrodes which are closely spaced and connected to opposite poles of a potential source. It is customary, in the prior art, to have at least one of the electrodes shaped in the form of the desired character.
  • various means have been devised to produce a uniform corona source and/or to focus the ions from a corona source on the receptor.
  • the receptor usually comprises a dielectric web or sheet which is moved relative to the electrodes as successive characters are presented to the receptor.
  • a charge pattern which in effect is an electrostatic latent image is formed on the receptor and subsequently developed by known techniques to produce a suitable visual image.
  • Prior an electrostatic printers have employed a multielement electrode which is divided into a matrix of elements which are selectively energized to form individual characters.
  • OBJECTS 'static printer in which the ion field is selectively controlled by means of a control grid which is switched at a relatively low potential.
  • an electrostatic printer having astable corona source, a grid, and a plate.
  • the printer deposits a controlled electrostatic charge pattern on a suitable receptor surface which is disposed in an ion path.
  • the deposited charge pattern is subsequently developed by applying powdered inks or toners as in prior art electrographic processes.
  • a multielement control grid is disposed in the ion path and close to the receptor.
  • the grid may take a variety of forms and may, for example, comprise an array of orthogonal wires for character generation by, points; or the grid may be a set of plates having bar and/or are type slits which, when used in various selected combinations, form the desired character.
  • FIG. 1 presents a simplified representation of an apparatus embodying the invention.
  • the apparatus includes an enclosing metallic member 10 which may include a small transparent area to permit inspection and observation.
  • a corona generating member 20 having one or more pointed ends or needles 21 is connected by a wire 25 to a first terminal 31 of a first potential source 30.
  • the second terminal 32 of said potential source 30 is electrically connected to a metallic platen 40.
  • a suitable receptor 50 Positioned in close proximity to the platen 40 is a suitable receptor 50.
  • the receptor 50 may take any of various forms which are well known in the art. Quite typically, the receptor 50 may comprise a mylar film which is metallized on the side facing the platen 40.
  • the receptor 50 may move from a supply reel 51 to a takeup reel 52 somewhat in the manner of tape in a tape recorder; or the receptor 50 may be arranged in a closed loop and be reused afler being erased by suitable means.
  • the receptor 50 may also comprise specially fonnulated or treated paper.
  • a grid 60 which is electrically connected to the swinger 71 of a transfer contact.
  • the back contact 72 is connected to the second terminal 32 of potential source 30 and also to the second terminal 82 of another potential source 80.
  • the front contact 73 of the transfer contact is connected to the first terminal 81 of potential source 80.
  • terminals 32 and 82 of potential sources 30 and 80 are of the same polarity, and may be either positive or negative.
  • the corona generating members 20 and 21 may be either positive or negative with respect to the platen 40. But in either case, as already stated, the terminals 32 and 82 are of the same polarity.
  • the potential sources 30 and are of unequal magnitude with source 30 being of considerably higher potential.
  • the potential 80 may be of the order of volts.
  • the actual potential for source 80 is a function of several factors, including: the intensity of the ion source, the duration of a voltage pulse (to be described later), the grid and receptor dimensions, and the development conditions.
  • the grid 60 may be selectively switched from the potential of terminal 82, which is the same as the potential of the platen 40, to the potential of terminal 81 which thereby places the grid at a potential between that of the platen 40 and that of the needles 21.
  • the transfer contacts comprising contacts 71, 72, and 73 be 'of the break-before-make variety; or if desired, protective resistors or any other suitable means could be used.
  • the purpose of shifting the grid 60 from one potential to the other will be shown hereinbelow.
  • Ions are pulled out of the corona field near needles 21 because of the potential of the grid 60 and/or the platen 40.
  • the ions may be beamed and focused by means disclosed in the prior art and familiar to those having experience in the electrostatic printer an. If the grid 60 is at the platen potential, all available ions will be attracted to the grid and none will penetrate to the receptor 50 or platen 40. However, if the grid 60 is at a potential between that of the platen 40 and the needles 21, ions will be enabled to penetrate the grid and an electrostatic image of the ion field will be formed on the receptor 50.
  • the grid 60 has a predetermined shape, it will be effective to permit the passage of ions past the grid in a controlled pattern and thereby deposit a charge on the receptor in a corresponding predetermined pattern. To obtain a variety of patterns or characters, it is obviously necessary to change the grid pattern.
  • the grid pattern can be altered by using a multielement grid with each element of the grid separately controlled or switched between the two terminals of potential source 80.
  • the grid 60 of FIG. 2 is composed of a plurality of separate elements 61, each of which are electrically insulated from each other element thereof.
  • Each grid element has a slot 62 therein and, as may be seen from an examination of FIG. 2, the slots 62 are arranged in a familiar figure 8" pattern so that any of the digits may be constructed by using selected combinations of the slots 62. All spaces 63 between the individual grid elements 61 are filled with insulating material.
  • Each grid element 61 is electrically connected to the swinger 71a to 713 of an individual transfer contact and each transfer contact may be independently operated to connect the corresponding grid element through front contacts 73a to 733 to terminal 81; or through back contacts 72a to 72g to tenninal 82 of potential source 80.
  • Any grid element 61 which is connected to terminal 82 is at the same potential as platen 40 and will attract all ions in that area and prevent any ions from passing through opening 62 of grid element 61 to the receptor 50.
  • any grid elements 6i which are connected to terminal 81 will enable ions to pass through their respective slots 62 and produce a corresponding charge pattern on receptor 50. Accordingly, with the grid shown in FIG. 2, it is possible to cause electrostatic images of any desired digit to be formed on the receptor 50.
  • the circuit comprising contacts 710, 72a, and 73a, etc. to 71g, 72g, and 73g may actually be any suitable form of logic circuitry and be controlled by any suitable means for selecting the desired character.
  • signals could be read from perforated tape or cards or magnetic tape for individually controlling the plurality of contacts 71a to 73g.
  • the specific control means do not form a part of this invention and, therefore, are not illustrated or described herein as such means is a matter of engineering choice using principles which are familiar to those having experience in the appropriate arts.
  • a more complicated grid 60 could be constructed with a greater plurality of elements 61 having bar and are openings 62 for forming alpha characters as well as numerics. It is not necessary that all grid elements 61 occupy the same plane.
  • the grid 60 may also take an entirely different form as shown in FIG. 3 and comprise an array of orthogonal wires.
  • the horizontal array (as viewed in FIG. 3) may be designated an X array and individual grid elements identified as 6lXa, 6IXb, etc., to 61Xn.
  • the vertical array (as viewed in FIG. 3)may be designated the Y array and individual grid elements identified as 61Ya, 6lYb, etc. to 6lYn.
  • Use of the grid of FIG. 3 permits printing and character formation in a manner similar to that used in matrix printers such as that disclosed in an application of E. O. BLodgett entitled "Serial Character Matrix Page Printer” filed Apr. 14, 1967, and issued Feb.
  • each individual grid wire may be selectively and individually connected to either terminal 81 or 82 of potential source 80.
  • Some of the individual contacts 71Xa to 73Yn for selectively connecting each of the plurality of grid wires of FIG. 3 to the required potential are shown. It should be understood that each of the plurality of grid wires is individually and selectively switched by individual contact sets or equivalents. By this means, it is possible to produce an enabling potential at any desired cross point by connecting the appropriate grid wires to potential terminal 81.
  • cross point 69 will be enabled and ions from the corona field could pass the grid at that point and leave an electrostatic image on the receptor. It may well be asked why a dot is printed at cross point 69 and not two lines or bars that cross at point 69. The point is well taken and probably either no printing would be obtained under the conditions given or else the two lines or bars corresponding to grid wires 6IXb and 6IYb would be printed.
  • the inhibiting effect of any grid wire connected to terminal 82 must have a band of inhibiting influence at least twice as wide as the spacing between parallel grid wires. This desired effect may be obtained by judicious grid design, and selection of potential of potential source 80.
  • grid wires 6IXb and 61Yb are enabled by being selectively connected to the potential at terminal 81 that there will be no printing at cross point 69 as the inhibiting influence of grid wires 6IXa, 6IXc, 6lYa, and 6lYc all provide a band of inhibiting influence which precludes the possibility of any ions being passed anywhere along the length of grid wires 6IXb or 6lYb.
  • the actual and practical method by which the grid of FIG. 3 may be used for selectively controlling the printing of selected characters will next be described.
  • any one or more of the grid wires 61Xa to 6lXn and 6lYa to 6lYn may be selectively connected to terminal 82 which is at substantially the same potential as terminal 32 and the platen 40.
  • Any grid wire so connected will have a potential which attracts all ions in the area thereof and prevents such ions from reaching the receptor; (b) The inhibiting band width of a grid wire connected to the inhibiting potential is at least equal to twice the width between adjacent parallel wires (but little, if any, more); (c) Any one or more of the grid wires 61Xa to 61Xn and 6IYa to 61Yn may be selectively connected to terminal 81 which has a polarity in the same direction as terminal 31 but a greatly reduced potential. Any grid wire so connected will have a potential which tends to allow ions to pass to the receptor; and (d) No ions will pass to the receptor as a result of a single enabled grid wire as the inhibiting influence of parallel adjacent grid wires is too great.
  • the grid elements of FIG. 2 might be fabricated on a printed circuit board with the grid elements 61 printed on both sides of the board. In some applications, both sides of corresponding grid elements would be electrically connected together while in other applications, there might be a resistor in the circuit coupling two corresponding elements. In some applications, the resistor would help to create a focusing grid and improve the focusing of the ions on the receptor 50 and thereby provide an improved image.
  • the grid elements 6lXa to 61Xn may be in one plane while the grid elements 61Ya to 61Yn may be in another parallel and closely spaced plane.
  • the printing rate may be increased by using the structure shown in FIG. 4.
  • the top half of FIG. 4 is substantially a duplication of FIG. 1 except that no platen 40 is included in FIG. 4.
  • the bottom half of FIG. 4 is substantially a mirror image of the top half.
  • the most significant difference between the top and bottom halves of FIG. 4 resides in the reversed potentials of one with respect to the other.
  • parts of the top half of FIG. 4 which correspond with equivalent parts shown in FIG. I are given identical numbers.
  • Elements in the bottom half of FIG. 4 which correspond with elements in the top half are given identical identification numbers except that they are primed.
  • the potential of source 30 is reversed with respect to source 30. Accordingly, needles 21 and 21' are at different potentials and one set of needles produces positive corona while the other set of needles produces negative corona.
  • the grids 60 and 60' can enable ions to be directed to the receptor 50 from both sides, thereby depositing a greater number of ions on the receptor in a given unit of time. By this means, an acceptable density of ion deposition can be obtained in a shorter time, thereby resulting in the equivalent of more rapid printing.
  • the grids 60 and 60 should be identical and should be switched in an identical manner at all times, although one grid is positive with respect to the other. That is, terminals 81 and 31 are at potentials in opposite directions.
  • the grids 60 and 60' may be of the form illustrated in FIGS. 2 or 3 or any other suitable form.
  • FIG. 4 does not have a platen similar to that shown as 40 in FIG. 1. However, if a receptor support is required, it would be possible to add a suitable edge support.
  • An electrostatic printer comprising:
  • a corona source coupled to said first potential source for generating a substantially continuous supply of ions
  • a receptor means positioned between said platen and said corona source for recording an electrostatic image of the charge pattern closely adjacent said platen;
  • a second potential source having a magnitude substantially less than said first potential source and greater than said reference potential and a polarity of the same sign as said first potential source;
  • said grid structure disposed between said receptor means and said corona source for regulating the flow of said ions toward said platen to control the configuration of said charge pattern, said grid structure comprising a plurality of electrically conductive elements insulated from each other;
  • switching means for selectively coupling said grid structure to said second potential source and to said reference potential, said switching means including a plurality of individually actuatable switching devices for coupling each of said plurality of elements to either of said potential source and said reference potential, individual ones of said switching devices being associated with individual ones of said plurality of elements;
  • each said switching device comprising a first member coupled to said reference potential, a second member coupled to said second potential source, a central member coupled to said associated grid element and means for coupling said central member to either of said first and second members.
  • said grid structure comprises a plurality of electrically conductive plate segments mutually separated by an electrically nonconductive substance, each said plate segment having a slotted opening therein, said segment openings being arranged to form a master character stencil.
  • said grid structure comprises a substantially coplanar array of a plurality of electrically conductive wires
  • said second subplurality of wires being disposed substantially perpendicular to said first subplurality of wires.
  • An electrostatic printer comprising:
  • first and second potential sources having substantially equal magnitudes and opposite polarities
  • first and second corona sources disposed on opposite sides of said receptor means and coupled respectively to said first and second potential sources for generating a substantially continuous supply of ions
  • first and second grid structures disposed between said first and second corona sources, respectively, and said receptor means for regulating the flow of said ions toward said platen to control the configuration of said electrostatic image, said first and second grid structures each comprising a plurality of electrically conductive elements insulated from each other;
  • third and fourth potential sources having substantially equal magnitudes and opposite polarities, the magnitude of said third and fourth potential sources being substantially less than the magnitude of said first ans second potential sources, respectively, said third and fourth potential sources having the same polarity as said first and second potential sources, respectively;
  • switching means for selectively coupling said first and second grid structures to said reference potential and said third and fourth potential sources, respectively, said switching means including first and second sets of individually actuatable switching devices for coupling corresponding ones of said plurality of elements of said first and second grid structures, respectively, to either of said third potential source and said reference potential, and either of said fourth potential and said reference potential, respectively;
  • each said switching device of said first and second sets comprising:
  • first and second grid structures define an image area and including means for moving said receptor means through said image area at a predetermined rate.
  • said first and second grid structures each comprise a plurality of electrically conductive plate segments mutually separated by an electrically nonconductive substance, each said plate segment having a slotted opening therein, said segment openings being arranged to form a master character stencil.
  • first and second grid structures each comprise a substantially coplanar array of a plurality of electrically conductive wires
  • said second subplurality of wires being disposed substantially perpendicular to said first subplurality of wires.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Dot-Matrix Printers And Others (AREA)
US806782A 1969-03-10 1969-03-10 Electrostatic printer Expired - Lifetime US3623123A (en)

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US80678269A 1969-03-10 1969-03-10

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US3623123A true US3623123A (en) 1971-11-23

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US806782A Expired - Lifetime US3623123A (en) 1969-03-10 1969-03-10 Electrostatic printer

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US (1) US3623123A (enExample)
DE (1) DE2011038A1 (enExample)
FR (1) FR2037859A5 (enExample)
GB (1) GB1279532A (enExample)
NL (1) NL7003122A (enExample)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3978492A (en) * 1971-09-25 1976-08-31 Agfa-Gevaert, A.G. Process for the electrographic recording of charge images in a low electron affinity case
US3986189A (en) * 1973-09-04 1976-10-12 Agfa-Gevaert N.V. Dielectrographic recording apparatus and method
US4208965A (en) * 1977-03-25 1980-06-24 Helmut Eichler Method for electrostatic assistance in printing processes, and printing machines having electrostatic substrate contact pressure
US4521792A (en) * 1983-08-29 1985-06-04 Xerox Corporation Ion projection printer with charge compensation source
US4527177A (en) * 1983-08-29 1985-07-02 Xerox Corporation Ion projection printer with virtual back electrode
US4864331A (en) * 1986-10-22 1989-09-05 Markem Corporation Offset electrostatic imaging process
US4899186A (en) * 1989-06-19 1990-02-06 Xerox Corporation Ionographic device with pin array coronode
US6285032B1 (en) * 1995-07-13 2001-09-04 Eltexelektrostatik Gmbh Device for removing the gaseous laminar boundary layer of a web

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2716826A (en) * 1951-10-24 1955-09-06 Huebner Company Apparatus for reproducing images
US2944147A (en) * 1955-12-21 1960-07-05 Ibm Xerographic printer
US3266046A (en) * 1961-01-24 1966-08-09 Le Febure Inc Electrostatic printer
US3277818A (en) * 1964-12-28 1966-10-11 Gen Micro Electronics Inc Electrostatic stencil apparatus for matrix printers
US3298030A (en) * 1965-07-12 1967-01-10 Clevite Corp Electrically operated character printer
US3306193A (en) * 1964-09-14 1967-02-28 Continental Can Co Electrostatic screen printing with magnetic conveyer and moving base electrode
US3358289A (en) * 1963-05-23 1967-12-12 Burroughs Corp Electrostatic transducer apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2716826A (en) * 1951-10-24 1955-09-06 Huebner Company Apparatus for reproducing images
US2944147A (en) * 1955-12-21 1960-07-05 Ibm Xerographic printer
US3266046A (en) * 1961-01-24 1966-08-09 Le Febure Inc Electrostatic printer
US3358289A (en) * 1963-05-23 1967-12-12 Burroughs Corp Electrostatic transducer apparatus
US3306193A (en) * 1964-09-14 1967-02-28 Continental Can Co Electrostatic screen printing with magnetic conveyer and moving base electrode
US3277818A (en) * 1964-12-28 1966-10-11 Gen Micro Electronics Inc Electrostatic stencil apparatus for matrix printers
US3298030A (en) * 1965-07-12 1967-01-10 Clevite Corp Electrically operated character printer

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3978492A (en) * 1971-09-25 1976-08-31 Agfa-Gevaert, A.G. Process for the electrographic recording of charge images in a low electron affinity case
US3986189A (en) * 1973-09-04 1976-10-12 Agfa-Gevaert N.V. Dielectrographic recording apparatus and method
US4208965A (en) * 1977-03-25 1980-06-24 Helmut Eichler Method for electrostatic assistance in printing processes, and printing machines having electrostatic substrate contact pressure
US4521792A (en) * 1983-08-29 1985-06-04 Xerox Corporation Ion projection printer with charge compensation source
US4527177A (en) * 1983-08-29 1985-07-02 Xerox Corporation Ion projection printer with virtual back electrode
US4864331A (en) * 1986-10-22 1989-09-05 Markem Corporation Offset electrostatic imaging process
US4899186A (en) * 1989-06-19 1990-02-06 Xerox Corporation Ionographic device with pin array coronode
US6285032B1 (en) * 1995-07-13 2001-09-04 Eltexelektrostatik Gmbh Device for removing the gaseous laminar boundary layer of a web

Also Published As

Publication number Publication date
FR2037859A5 (enExample) 1970-12-31
GB1279532A (en) 1972-06-28
NL7003122A (enExample) 1970-09-14
DE2011038A1 (de) 1970-09-17

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