EP0234903B1 - Copiage électrostatographique - Google Patents

Copiage électrostatographique Download PDF

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Publication number
EP0234903B1
EP0234903B1 EP19870301547 EP87301547A EP0234903B1 EP 0234903 B1 EP0234903 B1 EP 0234903B1 EP 19870301547 EP19870301547 EP 19870301547 EP 87301547 A EP87301547 A EP 87301547A EP 0234903 B1 EP0234903 B1 EP 0234903B1
Authority
EP
European Patent Office
Prior art keywords
film
pattern
paper
charges
radio
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
Application number
EP19870301547
Other languages
German (de)
English (en)
Other versions
EP0234903A3 (en
EP0234903A2 (fr
Inventor
Jack Adams Well Needham
John Arthur Kylemore Elvidge
James Henry 18 Groveland Road Semark
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Crosfield Muirhead Ltd
Original Assignee
Crosfield Muirhead Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Crosfield Muirhead Ltd filed Critical Crosfield Muirhead Ltd
Publication of EP0234903A2 publication Critical patent/EP0234903A2/fr
Publication of EP0234903A3 publication Critical patent/EP0234903A3/en
Application granted granted Critical
Publication of EP0234903B1 publication Critical patent/EP0234903B1/fr
Expired legal-status Critical Current

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Classifications

    • 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
    • G03G15/65—Apparatus which relate to the handling of copy material
    • G03G15/6597—Apparatus which relate to the handling of copy material the imaging being conformed directly on the copy material, e.g. using photosensitive copy material, dielectric copy 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
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00367—The feeding path segment where particular handling of the copy medium occurs, segments being adjacent and non-overlapping. Each segment is identified by the most downstream point in the segment, so that for instance the segment labelled "Fixing device" is referring to the path between the "Transfer device" and the "Fixing device"
    • G03G2215/00371—General use over the entire feeding path
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00443—Copy medium
    • G03G2215/00518—Recording medium, e.g. photosensitive
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
    • G03G2215/00535—Stable handling of copy medium
    • G03G2215/00654—Charging device

Definitions

  • the present invention relates to electrostatographic copying.
  • a particular application of the invention is to electrostatographic copying in conditions of high temperature and/or high humidity, for example, 45 ° c and/or 95% humidity.
  • a method of electrostatographic copying is known in which the copying is done onto electrostatic paper which has a film of highly electrically resistive material on a single side of the paper, the paper being impregnated with electrically conductive resin.
  • the known method comprises the steps of applying an electric field pattern to the paper so as to induce a pattern of charges of opposite polarity on opposite sides of the film (due to the field effect), discharging the charge pattern on one side of the film (by means of conduction through the resin-impregnated paper) while substantially retaining the charge pattern on the other side of the film, applying toner medium to the paper so that the toner medium adheres to the paper in the pattern of the retained charge, due to the retained charge, and fixing the toner medium in the aforesaid pattern.
  • a method of electrostatographic copying onto electrostatic paper which has a film of highly electrically resistive material on a single side of the paper, comprising the steps of applying an electric field pattern to the paper so as to induce a pattern of retained charges, applying toner medium to the paper so that the toner medium adheres to the paper in the pattern of the retained charges due to the retained charge, and fixing the toner medium in the aforesaid pattern, characterised in that the paper is exposed to emissions of particles from a radio-active source before, during or after applying the electric field pattern, so as to prevent a pattern of charges forming on, or discharge any pattern of charges formed on, one side of the film while permitting formation and substantial retention of a charge pattern of opposite polarity on the other side of the film.
  • an apparatus for electrostatographic copying onto electrostatic paper which has a film of highly electrically resistive material on a single side (16a) of the paper (16), comprising means (26,28) for applying an electric field pattern to the paper so as to induce a pattern of retained charge means (40,42) for applying toner medium to the paper so that the toner medium adheres to the paper in the pattern of the retained charges due to the retained charge, and means (44,46,48) for fixing the toner medium in the aforesaid pattern, characterised in that a radio-active source (52,54) arranged to expose the paper to emissions of particles from the radio-active source before, during or after the application of the electric field, so as to prevent a pattern of charges forming on, or discharge any pattern of charges formed on, one side of the film while permitting formation and substantial retention of a charge pattern of opposite polarity on the other side of the film.
  • a radio-active source 52,54
  • resin-impregnated paper may be used in the above-mentioned method and apparatus (other than in conditions of high temperature and/or high humidity, of course) the provision of the radio-active source obviates the need for resin-impregnated paper, since the energy of the particles from the radio-active source is sufficient to ionise the paper even without resin-impregnation.
  • the illustrated electrostatographic copying apparatus 10 comprises a housing 12 which contains a reel 14 of copying paper 16 which has no resin-impregnation but which has a film of highly electrically resistive material on a single side 16a of the paper 16 (and no such film on the other side 16b).
  • the paper 16 is arranged to pass out of the housing 12, via a roller 18, upwardly between two guides 20, 22 to a further roller 24, then between a selectively electrically energisable 'comb' 26 and a 'backplane' 28 to a pair of feed rollers 30, 32, then to a guillotine 34, then past a paper loop detector 36 to a toner box 38 having two rollers 40, 42 for applying toner (to the "out-side" of the film) and thence, via a stand of three pressure fix rollers 44, 46, 48 (the paper passing between the two upper rollers 44, 46) to an outlet 50.
  • the selectively electrically energisable comb 26 has, for example, 1728 copper wires (not shown) in two lines (not shown), for inducing a dot-matrix charge pattern on the paper according to the energisation of the wires as the paper passes between the comb 26 and the backplane 28.
  • the backplane 28, which is on the far side of the paper from the electrically resistive film, is maintained at a high positive voltage (for example, +600 volts). "Energisation" of the wires in the comb 26 takes the form of selective earthing of the wires.
  • the apparatus 10 includes means to achieve ionisation of the paper (but not the electrically resistive film) in the form of a radio-active source.
  • a radio-active source there are a number of possible positions for this radio active source, for example, just upstream of the comb 26 (as at 52) or just downstream of the comb 26 (as at 54) - see Figs. 1 and 2.
  • the radio-active source may for example be americium-241 or nickel-63 or polonium-210. More particularly, the particles emitted by the radio-active source may be of the same polarity as the eventually retained charge pattern or of the opposite polarity.
  • the radio-active source is on the opposite side of the paper from the film, whilst the side of the film from which the charge pattern is discharged, due to the ionisation of the paper by the particles from the radio-active source, is the side of the film in contact with the paper, i.e the "in-side" of the film.
  • the required radiation density may for example be 100 microcuries per square centimetre.
  • the charge pattern is induced on the paper by the field effect, as with conventional resin-impregnated paper, and the ionisation of the paper by the irradiation persists after the paper has left the region of the radio-active source, which is why it is possible to position the radio-active source either upstream (as at 52) or downstream (as at 54) of the backplane 28, by means of which the charge pattern is induced.
  • the film as with known resin-impregnated paper, is generally of synthetic resin.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Elimination Of Static Electricity (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)

Claims (15)

1. Méthode de copie électrostatographique sur un papier électrostatique qui comporte un film de matériau à résistance électrique élevée sur une seule face (16a) du papier (16), comprenant les étapes d'appliquer un motif par un champ électrique sur le papier, afin d'induire un motif de charges retenues, d'appliquer un médium tel que du toner sur le papier (16) afin que le toner se fixe sur le papier suivant le motif des charges retenues obtenu par la charge retenue, et de fixer le médium suivant ledit motif, caractérisée en ce que le papier (16) est exposé à des émissions de particules provenant d'une source radio-active (52, 54) avant, durant et après l'application du motif suivant le champ électrique, afin d'éviter la formation d'un motif de charges ou d'une décharge de tout motif de charges formé sur l'une des faces du film tout en permettant la formation et la rétention substantielle du motif de charge de polarité inverse sur l'autre face du film.
2. Méthode selon la revendication 1, caractérisée en ce que la source (52, 54) est sur la face opposée (16b) du papier par rapport au film, cette face étant la face intérne du film.
3. Méthode selon la revendication 1 ou 2, caractérisée en ce que l'application du toner est effectuée sur la face extérne du film.
4. Méthode selon l'une des revendications 2 à 3, caractérisée en ce qu'un nombre substantiel de particules sont des particules chargées de polarité opposée à celle des charges déchargées sur ladite face du film.
5. Méthode selon l'une des revendications 1 à 3, caractérisée en ce qu'un certain nombre de particules sont des particules chargées ayant la même polarité que la polarité des charges déchargées sur ladite face du film.
6. Méthode selon l'une des revendications 1 à 5, caractérisée en ce que la source utilise de l'américium-241, du nickel-63 ou du polonium-210.
7. Méthode selon l'une des revendications précédentes, caractérisée en ce que l'air ionisé produit par l'émission effectuée par la source radio-active est positivement empêché d'atteindre' l'autre face du film afin d'éviter le déchargement de tout motif de charge retenue et ce, au moyen d'un motif en écoulement d'air réalisé de manière que ladite autre face du film est en amont et/ou est soumise à une pression supérieure par rapport à celle de l'endroit où se trouve l'air qui est ionisé.
8. Appareil pour la copie électrostatographique sur un papier électrostatique qui comporte un film de matériau à haute résistance électrique sur l'une de ses faces (16a) et comprenant des moyens (16, 28) pour appliquer un motif suivant un champ électrique sur le papier afin d'induire un motif suivant les charges retenues, un moyen (40, 42) pour appliquer un médium tel que du toner au papier afin que le toner adhère au papier suivant le motif des charges retenues obtenu grâce à une charge retenue et un moyen (44, 46, 48) pour fixer le toner sur ledit motif, caractérisé en ce qu'une source radio-active (52, 54) est arrangée pour exposer le papier à des émissions de particules provenant de la source radio-active avant, durant et après l'application du champ électrique, afin d'éviter la formation de motifs suivant des charges, ou la décharge de tout motif de charges formé sur le papier, sur l'une des faces du film tout en permettant la rétention substantielle d'un motif de charge de polarité opposée sur la face opposée du film.
9. Appareil selon la revendication 8, caractérisé en ce que la source (52, 54) est située sur la face opposée (16b) du papier (16) par rapport au film, ladite face étant la face interne du film.
10. Appareil selon la revendication 8 ou 9, caractérisé en ce que le moyen (40, 42) pour appliquer le toner est arrangé pour appliquer celui-ci sur la face externe du film.
11. Appareil selon l'une des revendications 8 à 10, caractérisé en ce que la source radio-active (52, 54) est telle qu'un certain nombre de particules sont des particules chargées ayant une polarité opposée à la polarité des charges déchargées sur ladite face du film.
12. Appareil selon l'une des revendications 8 à 10, caractérisé en ce que la source radio-active (52, 54) est telle qu'un nombre substantiel des particules sont des particules chargées ayant la même polarité que la polarité des charges déchargées sur ladite face de film.
13. Appareil selon l'une des revendications 8 à 12, caractérisé en ce que la source utilise de l'américium-241, du nickel-63 ou du polonium-210.
14. Appareil selon l'une des revendications 8 à 13, caractérisé en ce que, pour positivement éviter que l'air ionisé produit par l'émission effectuée par la source radio-active ne vienne atteindre l'autre face du film et décharger le motif suivant la charge retenue, un moyen d'écoulement d'air est prévu pour produire un écoulement d'air suivant un motif tel que ladite autre face du film est située en amont et/ou est soumise à une pression d'air supérieure à celle de l'emplacement où se trouve l'air ionisé.
15. Appareil selon l'une des revendications 8 à 14, caractérisé en ce que le moyen d'application du champ électrique (26, 28) comprend un tamis d'électrodes arrangées à proximité du papier et un moyen formant interrupteur électrique sélectivement actionné.
EP19870301547 1986-02-21 1987-02-23 Copiage électrostatographique Expired EP0234903B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8604369 1986-02-21
GB08604369A GB2188590A (en) 1986-02-21 1986-02-21 Electrostatographic copying

Publications (3)

Publication Number Publication Date
EP0234903A2 EP0234903A2 (fr) 1987-09-02
EP0234903A3 EP0234903A3 (en) 1988-03-02
EP0234903B1 true EP0234903B1 (fr) 1990-06-20

Family

ID=10593468

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19870301547 Expired EP0234903B1 (fr) 1986-02-21 1987-02-23 Copiage électrostatographique

Country Status (3)

Country Link
EP (1) EP0234903B1 (fr)
DE (1) DE3763344D1 (fr)
GB (1) GB2188590A (fr)

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5535338A (en) * 1978-09-01 1980-03-12 Sharp Corp Copying machine

Also Published As

Publication number Publication date
EP0234903A3 (en) 1988-03-02
DE3763344D1 (de) 1990-07-26
GB8604369D0 (en) 1986-03-26
GB2188590A (en) 1987-10-07
EP0234903A2 (fr) 1987-09-02

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