EP0712056B1 - Dispositif d'impression électrostatique direct avec tête d'impression spéciale - Google Patents

Dispositif d'impression électrostatique direct avec tête d'impression spéciale Download PDF

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Publication number
EP0712056B1
EP0712056B1 EP19950202968 EP95202968A EP0712056B1 EP 0712056 B1 EP0712056 B1 EP 0712056B1 EP 19950202968 EP19950202968 EP 19950202968 EP 95202968 A EP95202968 A EP 95202968A EP 0712056 B1 EP0712056 B1 EP 0712056B1
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EP
European Patent Office
Prior art keywords
printhead structure
printhead
frame
bars
fixed
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
Application number
EP19950202968
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German (de)
English (en)
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EP0712056A1 (fr
Inventor
Jacques c/o Agfa-Gevaert N.V. Leonard
François c/o Agfa-Gevaert N.V. Backeljauw
Guido C/O Agfa-Gevaert N.V. Desie
André c/o Agfa-Gevaert N.V. Van Geyte
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Agfa Gevaert NV
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Agfa Gevaert NV
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Publication date
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Priority to EP19950202968 priority Critical patent/EP0712056B1/fr
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Anticipated expiration legal-status Critical
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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
    • G03G15/34—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
    • G03G15/346—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 by modulating the powder through holes or a slit
    • 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
    • B41J2/415—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 by passing charged particles through a hole or a slit
    • B41J2/4155—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 by passing charged particles through a hole or a slit for direct electrostatic printing [DEP]
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2217/00—Details of electrographic processes using patterns other than charge patterns
    • G03G2217/0008—Process where toner image is produced by controlling which part of the toner should move to the image- carrying member
    • G03G2217/0025—Process where toner image is produced by controlling which part of the toner should move to the image- carrying member where the toner starts moving from behind the electrode array, e.g. a mask of holes

Definitions

  • This invention relates to the process Direct Electrostatic Printing (DEP).
  • DEP Direct Electrostatic Printing
  • electrostatic printing is performed directly on a substrate by means of electronically addressable printheads and the toner has to fly in an imagewise manner towards the receiving substrate.
  • the present invention relates to the printhead structure.
  • the toner or developing material is deposited directly in an imagewise way on a substrate, the latter not bearing any imagewise latent electrostatic image.
  • the substrate can be an intermediate, in case it is preferred to transfer said formed image on another substrate (e.g. aluminum, etc..), but it is preferentially the final receptor, thus offering a possibility to create directly the image on the final receptor, e.g. plain paper, transparency, etc.... after a final fusing step.
  • the final substrate can be different materials, such as a transparent medium, opaque polymeric films, paper, etc....
  • DEP is also markedly different from electrophotography in which an additionnal step and additionnal member is introduced to create the latent electrostatic image, more specifically, a photoconductor is used and a charging/exposure cycle is necessary.
  • a DEP device is disclosed in US-P 3,689,935.
  • This document discloses an electrostatic line printer comprising a multilayered particle modulator or printhead comprising a layer of insulating material, a continuous layer of conductive material on one side of the layer of the insulating material and a segmented layer of conductive material on the other side of the layer of the insulating Material.
  • the printhead comprises also at least one row of printing apertures.
  • Each segment of the segmented layer of conductive material is formed around a portion of an aperture and is insulatively isolated from each other segment of the segmented conductive layer. Selected potentials are applied to each of the segments of the segmented conductive layer while a fixed potential is applied to the continuous conductive layer.
  • An overall applied propulsion field projects charged particles through a row of printing apertures of the particle modulator (printhead) and the intensity of the particle stream is modulated according to the pattern of potentials applied to the segments of the segmented conductive layer.
  • the modulated stream of charged particles impinges upon a print-receiving medium interposed in the modulated particle stream and translated in a direction relative to the particle modulator (printhead) to provide a line-by-line scan printing.
  • the segmented electrode is called the control electrode and the continuous electrode is called the shield electrode.
  • the shield electrode faces, e.g. the toner supply and the control electrode faces the image recording member.
  • a DC field is applied between the printhead and a backing electrode and this propulsion field is responsible for the attraction of toner to the imaging receiving member that is placed between the printhead and the backing electrode.
  • toning particles are selected from the toner offering means through the printing apertures to reach receiving members at a fixed distance.
  • GB 2,108,432 means are disclosed for realising a stable and uniform supply of toner particles to the printhead. Therefore a conveying member is provided on which a layer of toner particles is deposited and an AC voltage is applied between the toner conveying member and the continuous layer of conductive material on the printhead structure. Due to this AC voltage the toner particles "jump" between the toner conveying member and the surface of the printhead facing said toner conveying member, forming a "toner-cloud".
  • EP-A 266 961 a toner delivery system is disclosed in which a monolayer of toner is deposited on the surface of the toner conveying means using a multi-component developer (carrier/toner) and a conventional magnetic brush.
  • a device for direct electrostatic printing (DEP) on an intermediate substrate or on a final substrate comprising a back electrode, a printhead structure made from an insulating material comprising a control electrode in combination with printing apertures, a toner delivery means presenting a cloud of toner particles in the vicinity of said printing apertures characterised in that said printhead structure is thightly stretched over a frame by means of lateral forces applied to said printhead structure and said printhead structure has an overall flatness equal or better than 50 ⁇ m.
  • both said printhead structure and said frame are rectangular or square and said lateral forces are exerted on every side of said printhead structure.
  • said lateral forces are exerted on said printhead structure via resilient elements.
  • Fig. 1 is a schematic illustration of a possible embodiment of a DEP device.
  • Fig 2. is a schematic illustration of a printhead structure stretched over a two bar frame.
  • Fig 3. is a schematic illustration of an other embodiment of a printhead structure stretched over a two bar frame.
  • Fig 4. is a schematic illustration of a printhead structure to stretched over a four bar frame.
  • Fig 5. is a schematic illustration of an other embodiment of a printhead structure stretched over a four bar frame.
  • Fig 6. is a schematic illustration of still an other embodiment of a printhead structure stretched over a four bar frame.
  • a possible embodiment of device for implementing DEP comprises (fig 1):
  • This thin printhead structure has to be mounted as close as possible to the toner receiving subtrate since this limits the spreading of the toner particles before they reach the receiving substrate.
  • the distance between printhead and receiving substrate is normally between 5 and 1000 ⁇ m, preferably between 25 and 500 ⁇ m.
  • a printhead structure made from an insulating material and comprising a control electrode, wherein said insulating material is preferably a plastic material and said control electrode is preferably made of metal, can be mounted very flat when said printhead structure (106) is thightly stretched over a frame by means of lateral forces applied to said printhead.
  • the printhead structure is preferably stretched so that the overall flatness of said printhead structure when stretched over said frame becomes equal or better than 50 ⁇ m.
  • the overall flatness of the printhead structure is better than 25 ⁇ m.
  • the overall flatness of the printhead structure is defined as the top to top topological value, measured by scanning the printhead structure over the total witdth with an optical (contactless) profilometer at a spatial resolution of 125 point/mm and a height resolution better than 1 ⁇ m.
  • Said frame can have any form, it can be circular, elliptic, polygonal, triangular, square, rectangular, etc..
  • the frame can be only one bar, over which the printhead structure is stretched.
  • said frame consists of 2 parallel bars whereover the printhead structure is stretched.
  • Preferably said frame is either square or rectangular.
  • said square or rectangular frame does not have to be a closed rectangle or square.
  • Said frame can comprise only four straight bars, positioned along the sides of a rectangle or square, in such a way that the elongation of each of said bars in both directions would yield a rectangle or a square.
  • the bars (both single bar, the bars that are arranged as a pair of parallel bars and the bars arranged along the four sides of a square or rectangle) have to fit in a two dimensional plane within a tolerance of 50 ⁇ m, preferably 25 ⁇ m.
  • the overall flatness of at least one bar of the frame, but preferably of each individual bar, contacting the printhead structure is preferably better than 50 ⁇ m, more preferably beter than 25 ⁇ m. This flatness, defined as the top to top topological value, measured by scanning the surface of the bar over the total length with an optical (contactless) profilometer at a spatial resolution of 125 point/mm and a height resolution better than 1 ⁇ m,
  • the bars, used in the device according to the present invention can be made of any material suitable to be machined to a flatness better than 50 ⁇ m, preferably better than 25 ⁇ m.
  • Very suitable materials are, e.g., copper, stainless steel, etc.
  • the shape of said bars can vary widely. It can be simple cylinders, hollow cylinders, profiles of any shape, e.g. T-profiles, U-profiles, open rectangular profiles, etc.
  • the bars, used in the frame to be used in a device according to the present invention, can be built into a larger framework.
  • This lager framework can be made of any material that can be machined to keep the tolerances applied to the frame formed by the bars.
  • the larger frame work can also be injection moulded. In this case it is possible to injection mould a framework wherein the bars forming the frame can seperatly be mounted or with the bars forming the frame already included in the larger framework.
  • Suitable materials to build the larger framework are, e.g., PVC (polyvinylchloride), (fiber reinforced) epoxy resins, bakelite, aluminium, etc.
  • the printhead structure comprises an insulating material, which is preferably a plastic material.
  • the plastic material can be any polyester, (fiber reinforced) epoxy resins, polyimide resins, etc.
  • the use of polyimide resins as insulating material is the most preferred for producing printhead structures according to the present invention.
  • the printhead structure comprises also metal layers applied to said plastic insulating material. These metal layers are preferably between 1 and 50 ⁇ m thick, more preferably between 3 and 20 ⁇ m. The metal layer can eventually be a multi-layer of different metals or of the same metal.
  • the insulating material is preferably between 20 and 200 ⁇ m thick, most preferably between 25 and 100 ⁇ m.
  • the printhead structure is stretched over said frame by lateral forces.
  • lateral forces is meant forces that are exerted in the plane of the printhead structure or at a small angle out of the plane of the printhead structure and pointing away from the center of said printhead structure.
  • the small angle out of the plane of the printhead structure means that the forces are applied under an angle of at least 135 °.
  • the forces can be exerted by any means, e.g. the printhead structure can be stretched by fitting it between two frames fitting snuggly one over another for holding the printhead structure taut as e.g.is done in an embroidery frame.
  • the lateral forces can also be applied by the own resilience of the material whereof the printhead structure is made. In that case the printhead structure is stretched over the bars forming the frame and firmly attached (e.g. glued) to the bars.
  • the lateral forces are preferably applied by external resilient means, e.g. rubber bands, coil springs, etc.
  • the printing apertures (107) are arranged in the close vicinity of said bar, while the row(s) of said apertures are parallel to said bar.
  • auxilliary bars together with a main bar, can be present.
  • said main bar has to fulfil the flatness requirement of 50 ⁇ m, preferably 25 ⁇ m.
  • the printing apertures (107) are arranged in the close vicinity of said main bar, while the row(s) of said apertures are parallel to said main bar (see e.g. figure 2). For the highest flatness, it is preferred to locate the printing apertures (107) as close as possible to said bar. The practical distance of the said apertures from said bar is dictated by the physical shape of the toner delivery means (101).
  • the printhead structure can be either square or rectangular, having one dimension longer than the distance between the two bars forming the frame and an other dimension smaller than the length of the bars forming the frame (in case of a square printhead, the sides of the square must both be larger than the distance between the bars and smaller then the length of said bars).
  • FIG 2 a possible embodiment of a printhead structure stretched over a two bar frame is shown.
  • Lateral forces are exerted on the printhead structure 106, extending over the bars 111a and 111b, by fixing one side (106c) of the printhead structure 106, extending over bar 111a in a non-resilient way (or using only the own resilience of the printhead structure 106) and fixing the other side (106d) of the printhead structure 106, extending over bar 111b, in a resilient way by coil springs 112.
  • the lateral forces are, at both sides, exerted under an angle ⁇ , being larger than 135 °. For sake of clarity in the figures 2 to 6 only one angle ⁇ is shown.
  • both sides are fixed in a resilient way, as shown in figure 3.
  • Lateral forces are exerted on the printhead structure 106, by fixing both side (106c and 106d), extending over the bars 111a and 111b, in a resilient way by coil springs 112.
  • the lateral forces are, on both sides, exerted under an angle ⁇ , being larger than 135 °.
  • the printhead structure is stretched over said bars by lateral forces exerted at an angle greater than 135 °, preferably an angle greater than 155 ° and most preferably over angle greater than 165 °. (180 ° being the plane of the printhead structure).
  • the location of the printing apertures (107) in the printhead structure can, in case of a two bar frame, be chosen in the middle between said two bars, but preferably the printing apertures are located in the vicinity of one of the bars, preferably at a distance from one of said bars equal to or lower than a fourth of the distance between the two bars.
  • the embodiment reverts to a one bar frame, wherein one auxilliary bar is present.
  • the printing apertures (107) are arranged in the close vicinity of said main bar, while the row(s) of said apertures are parallel to said main bar (see e.g. figure 2).
  • the practical distance of the said apertures from said bar is dictated by the physical shape of the toner delivery means (101).
  • both bars fulfil the flatness requirement of 50 ⁇ m, preferably 25 ⁇ m.
  • the printhead structure is preferably rectangular or square, and is in every direction longer than the distance between two opposite bars.
  • the corners of the rectangular or square printhead structure, extending beyond the bars forming the frame, are preferably cut away.
  • the cut-aways preferably have a form that avoids the concentration of stress, induced by stretching the printhead structure (106), in a single point.
  • the exact form of the cut-away for relieving stress concentration can be calculated from the properties of the materials wherefrom the printhead structure is made and from the lateral forces exerted on said printhead structure. This means that the cut-away will be a polygon and in the limit a fluent curve, with a form adapted to the properties of the printhead strucure and the forces exerted on it.
  • the corners of the rectangular or square printhead structure are cut away so that the width of the portions extending over each of said four bars, is lower than the length of the individual bar whereover every individual extending portion is stretched.
  • the printhead structure may be stretched over said four bar frame in different ways.
  • figure 4 a possible embodiment is shown.
  • Two adjacent sides (106 c and 106e) of the printhead structure (106) extending over bars 111a and 111d, are fixed in a non resilient way (or by using only the own resilience of the material of which the printhead structure (106) is made), the two other sides (106 d and 106 f) of the printhead structure (106) are fixed by resilient means, coil spring 112.
  • the printing apertures 107 are preferably located in the middle of the printhead structure. On the four sides the lateral forces are exerted under an angle ⁇ being larger than 155 °.
  • FIG. 5 Another possible embodiment using a four bar frame is shown in figure 5.
  • One side (106e) of the printhead structure (106), extending over bar 111d, is fixed in a non resilient way (or using the own resilience of the material of which the printhead structure (106) is made), and the three other sides (106c, 106d, 106f) of the printhead structure (106), extending over bars 111a, 11b, 111c, are fixed by resilient means, the coil springs 112.
  • the printing apertures 107 are preferably located in the middle of the printhead structure. On the four sides the lateral forces are exerted under an angle ⁇ being larger than 155 °.
  • FIG 6 the most preferred embodiment for stretching a printhead structure over a four bar frame is shown.
  • the four sides (106c, 106d, 106e 106 f) of the printhead structure (106), extending over bars 111a, 111b, 111c and 111d, are fixed by resilient means, the coil springs 112.
  • the printing apertures 107 are preferably located in the middle of the printhead structure.
  • On the four sides the lateral forces are exerted under an angle ⁇ being larger than 155 °.
  • the printhead structure is stretched over said bars by lateral forces exerted at an angle greater than 155 ° and preferably over angle greater than 165 °. (180 ° being the plane of the printhead structure).
  • the embodiment reverts to a one bar frame, wherein three auxilliary bars are present and a flat main bar.
  • the printing apertures (107) are arranged in the close vicinity of said main bar, while the row(s) of said apertures are parallel to said main bar.
  • a four frame bar that at least the two opposite bars fulfil the flatness requirement of 50 ⁇ m, preferably 25 ⁇ m. In the most preferred enbodiment, all four bars fulfil said flatness requirement.
  • the use of resilient means to exert lateral forces on the printhead structure offers the advantage that the flatness is kind of self rectifying, independently of the variations of temperature or of aging of the materials, the flatness of the printhead structure is guaranteed.
  • Said resilient means can be attached to holes in the sides of the printhead structure.
  • the vicinity of said holes is preferably reinforced. This reinforment can be effected by any means known in the art, E.g. by having ticker plastic along the edges, by having a thicker metal layer along the edge, by having metal ring aroud the holes, etc.
  • the resilient means can be attached to the printhead structure by clamping means not necessitating the punching of holes in the printhead structure.
  • the magnitude of the forces applied to the printhead structure is determined by the material in the printhead structure having the lowest limit of elasticity, since otherwise permanent deformations of the printhead structure are observed.
  • the forces, applied to said printhead structure have to be such that the stress exerted by the streching of said printhead structure, does not bring about a deformation (elongation) exceeding 5 %.
  • the stress induced in the printhead structure in said two perpendicular directions may be equal. It is preferred that the stress, induced along the line (rows) of the printing printing apertures (107) is larger than the stresses induced perpendicular to the rows (i.e. parallel to the columns) of said printing apertures (107).
  • the anisotropy of the stresses induced in the printhead structure is preferably in the range 6:1 to 1:6, most preferably in the range 3:1 to 1:3, i.e. the lateral forces are preferably exerted anisotropically with an anisotropy factor between 6:1 to 1:6, most preferably in the anisotropy factor lies between 3:1 to 1:3.
  • a printhead structure, held flat by means according to the present invention can be used in any DEP device. It can e.g. be used in devices using toner conveyer means to present a monolayer of toner in the vicinity of the printhead structure, as disclosed in e.g. US-P 4,743,926, US-P 4,780,733, DE-OS 3411948, EP-A 266 960, etc. It can be used in devices where the toner is presented to the printhead from a magnetic brush as disclosed in e.g. US-P 5,327,169. It can be used in devices where the uniform toner cloud in the vicinity of the printhead structure is provided by oscillating fields or by mechanical means as is disclosed in e.g. US-P 5,202,704.
  • the printing apertures (107) in the printhead structure, held flat by means according to the present invention can be of any form, the holes can be formed as disclosed in e.g. US-P 3,689,935, GB-A 2,108,432 etc.
  • the printing apertures (107) in the printhead structure, held flat by means according to the present invention can be present in one row or in multiple rows, they can be staggered or non staggered, etc.
  • a printhead structure held flat by means according to the present invention, can be used in devices comprising a full back electrode (105) or a segmented back electrode.
  • Said printhead structure can be used with any developer, monocomponent or multicomponent, with coloured or black or colourless toners, developers comprising fluidity improvers as e.g. hydrophobic silica particles, etc.

Claims (16)

  1. Dispositif pour l'impression électrostatique directe (DEP) sur un substrat intermédiaire ou sur un substrat final, comprenant une contre-électrode (105), une structure de tête d'impression (106) constituée d'un matériau isolant comprenant une électrode de commande combinée à des ouvertures d'impression (107), un moyen de distribution de toner (101) présentant un nuage (104) de particules de toner dans le voisinage desdites ouvertures d'impression (107), caractérisé en ce que
       ladite structure de tête d'impression (106) est tendue raide par-dessus un cadre au moyen de forces latérales appliquées sur ladite structure de tête d'impression, et ladite structure de tête d'impression (106) présente une planéité globale égale à, ou meilleure que, 50 µm.
  2. Dispositif selon la revendication 1, dans lequel ladite planéité globale de ladite structure de tête d'impression (106) est égale à, ou meilleure que, 25 µm.
  3. Dispositif selon la revendication 1 ou 2, dans lequel lesdites forces latérales sont appliquées par des moyens élastiques.
  4. Dispositif selon la revendication 3, dans lequel lesdits moyens élastiques sont des ressorts hélicoïdaux.
  5. Dispositif selon l'une quelconque des revendications 1 à 4, dans lequel ledit cadre est un cadre à deux barres et ladite structure de tête d'impression est soit carrée, soit rectangulaire.
  6. Dispositif selon la revendication 5, dans lequel un côté de ladite structure de tête d'impression est fixé d'une manière non élastique et le côté opposé est fixé par des moyens élastiques.
  7. Dispositif selon la revendication 5, dans lequel ladite structure de tête d'impression est fixée des deux côtés par des moyens élastiques.
  8. Dispositif selon l'une quelconque des revendications 5 à 7, dans lequel lesdites forces latérales sont appliquées sur ladite structure de tête d'impression selon un angle supérieur à 135°.
  9. Dispositif selon l'une quelconque des revendications 1 à 4, dans lequel ledit cadre est un cadre à quatre barres et et ladite structure de tête d'impression est soit carrée, soit rectangulaire.
  10. Dispositif selon la revendication 9, dans lequel un côté de ladite structure de tête d'impression est fixé d'une manière non élastique et les trois autres côtés sont fixés par des moyens élastiques.
  11. Dispositif selon la revendication 9, dans lequel deux côtés adjacents de ladite structure de tête d'impression sont fixés d'une manière non élastique et les deux autres côtés adjacents sont fixés par des moyens élastiques.
  12. Dispositif selon la revendication 9, dans lequel les quatre côtés de ladite structure de tête d'impression sont fixés par des moyens élastiques.
  13. Dispositif selon l'une quelconque des revendications 9 à 12, dans lequel lesdites forces latérales sont appliquées sur ladite structure de tête d'impression selon un angle supérieur à 155°.
  14. Dispositif selon l'une quelconque des revendications 9 à 13, dans lequel l'anisotropie desdites forces latérales est comprise entre 6:1 et 1:6.
  15. Dispositif selon l'une quelconque des revendications 9 à 14, dans lequel les coins de ladite structure de tête d'impression sont découpés.
  16. Dispositif selon l'une quelconque des revendications 5 à 15, dans lequel l'une au moins desdites barres présente une planéité globale meilleure que 50 µm.
EP19950202968 1994-11-08 1995-11-02 Dispositif d'impression électrostatique direct avec tête d'impression spéciale Expired - Lifetime EP0712056B1 (fr)

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EP19950202968 EP0712056B1 (fr) 1994-11-08 1995-11-02 Dispositif d'impression électrostatique direct avec tête d'impression spéciale

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EP94203255 1994-11-08
EP94203255 1994-11-08
EP19950202968 EP0712056B1 (fr) 1994-11-08 1995-11-02 Dispositif d'impression électrostatique direct avec tête d'impression spéciale

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EP0712056A1 EP0712056A1 (fr) 1996-05-15
EP0712056B1 true EP0712056B1 (fr) 1999-08-04

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Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0795802A1 (fr) * 1996-03-15 1997-09-17 Agfa-Gevaert N.V. Structure d'une tête d'impression fabriquée par revêtement autocatalytique sur un substrat plastique
US6102523A (en) * 1996-12-19 2000-08-15 Agfa-Gevaert Printer for large format printing using a direct electrostatic printing (DEP) engine
DE69620204T2 (de) 1996-12-23 2002-10-24 Agfa Gevaert Nv Drucker und Druckverfahren
US6227655B1 (en) 1997-04-09 2001-05-08 Agfa-Gevaert DEP (direct electrostatic printing) device maintaining a constant distance between printhead structure and toner delivery means
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