EP0024234B1 - Procédé de reproduction electrographique sur un support par développement inverse et fixage par pression - Google Patents

Procédé de reproduction electrographique sur un support par développement inverse et fixage par pression Download PDF

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Publication number
EP0024234B1
EP0024234B1 EP80401156A EP80401156A EP0024234B1 EP 0024234 B1 EP0024234 B1 EP 0024234B1 EP 80401156 A EP80401156 A EP 80401156A EP 80401156 A EP80401156 A EP 80401156A EP 0024234 B1 EP0024234 B1 EP 0024234B1
Authority
EP
European Patent Office
Prior art keywords
carrier
image
powder
charges
development
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
EP80401156A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0024234A1 (fr
Inventor
Donald 1 résidence des Trois Chênes Kings
Pham Kim Quang
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.)
Rhone Poulenc Systemes SA
Original Assignee
Rhone Poulenc Systemes SA
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 Rhone Poulenc Systemes SA filed Critical Rhone Poulenc Systemes SA
Priority to AT80401156T priority Critical patent/ATE9515T1/de
Publication of EP0024234A1 publication Critical patent/EP0024234A1/fr
Application granted granted Critical
Publication of EP0024234B1 publication Critical patent/EP0024234B1/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
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/06—Developing
    • G03G13/08—Developing using a solid developer, e.g. powder developer
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/06—Eliminating residual charges from a reusable imaging member
    • G03G21/08—Eliminating residual charges from a reusable imaging member using optical radiation
    • 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
    • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/001—Electric or magnetic imagery, e.g., xerography, electrography, magnetography, etc. Process, composition, or product
    • Y10S430/104—One component toner

Definitions

  • the present invention relates to a method of electrographic reproduction on a support by reverse development and pressure fixing, in which an image of charges previously formed on the support, in a manner known per se, is developed in a reverse manner using a powder of suitable development, the powder image zones corresponding to zones in which there are no charges and vice versa, said powder image then being fixed on said support, by passage of the latter between pressure rollers connected to earth, which adhere the powder to the support.
  • This type of fixing has the advantage of being simple, because generally metal rollers are used, the machining of which does not present any particular difficulties.
  • this type of device does not present any danger when the copy is blocked in it, unlike heat fixing devices in which blocking the copy can cause a fire in the machine.
  • the method according to the invention makes it possible to avoid this drawback: it is characterized in that the image of charges is neutralized after development but before fixing, by the metal pressure rollers.
  • the method according to the invention can be implemented in different ways.
  • the method according to the invention is characterized in that the neutralization of the image of charges is caused by illumination of the support.
  • the back of the support through a slot, arranged transversely with respect to the direction of advance thereof and over its entire width.
  • the charge image is previously formed on the support, which is photoconductive, in the usual way, that is to say that after uniform loading of the photoconductive support using a charging device corona (or other similar device), the charge image is created by exposure to light through the semi-transparent original to be reproduced, so that the lit areas are discharged, while the unlit areas are kept charged .
  • the image is then developed from reverse.
  • the method according to the invention is characterized in that the neutralization of the image of charges is caused by the emission of charges of sign opposite to that of the image of charges.
  • the image is developed with a developing powder depositing in the uncharged areas.
  • Any well-known development method can be used. This is how we can use cascade development as described in US Pat. Nos. 2,618,551, 2,618,552 or 2,638,416. In such a development process, it is necessary to use a so-called “two-component” development powder which comprises on the one hand large particles called carrier (“carrier”) and fine colored particles of developer (“toner”). These particles generally consist of synthetic resinous materials which must have the property of being charged by triboelectricity. We choose these resins in the triboelectric series according to the result we want to obtain. Thus, in the case where it is desired to obtain negatively charged developer particles, the resin constituting these will be chosen a resin located below, in the triboelectric series, that constituting the support particles which are charged, they positively, and vice versa.
  • the carrier particles not having a developer role it is necessary that these have a sufficient weight to be able to flow by gravity: only the developer particles adhere to the support.
  • the support particles contain in particular magnetic materials.
  • the magnetic brush constituted by series of rotating magnets, magnetically attracts the particles on its surface, said support particles retaining, by triboelectricity, the generally non-magnetic developing particles.
  • the Applicant prefers, however, to use a "single-component" developing powder, in which all the particles are magnetic developer particles which are transferred under the action of an external electric field.
  • a resin for coating the magnetic particles having better electrical conductivity will be chosen in the case of a photoconductive copy medium, than in the case of a non-photoconductive dielectric medium (plain paper, plastic, etc. ..).
  • developer particles of the "single-component" type use will be made preferably of particles specially designed for fixing by pressure, such as those described in French patents 2,167,047, 2,167,143, 2,235,404, etc.
  • the upper cylinder must be made of very hard and electrically conductive material.
  • electrophotographic paper sold under the trade name REGMA M 100 BC, composed of a substrate 1 and an electrophotographic layer 2 positive charges 4 are uniformly deposited using a corona 3 with two wires spaced 6 mm apart from one 'other and located 17 mm from the paper ( Figure 1 a), the paper moves in front of the corona at a speed of 7,7 cm / s.
  • the corona is supplied with a continuous voltage of 6,500 volts.
  • the residual surface tension of the loaded paper, after 10 seconds, is 270 volts (voltage measured on KETHLEY ELECTROMETER 61 OB with probe 2501).
  • the electrophotographic paper is then exposed through an original 5 consisting of a 75% magenta glass screen, used in projection, composed of pairs of equal black and white lines, perpendicular, in steps of 150 pairs per inch.
  • the light radiation 6 (FIG. 1 b) is delivered by a PHILIPS Photocrescenta bulb of 150 watts, delivering 61 Lux at the level of the photosensitive paper.
  • the enlargement ratio used is 3/1.
  • the charge image thus obtained is developed using a negative one-component toner 7, for pressure fixing, sold under the trade name HITACHI-MI-TONER HMT 601 (FIG. 1 c).
  • a magnetic brush with a fixed aluminum envelope and movable magnets was used which rotated at the speed of 500 revolutions / min so as to move the toner in the direction of travel of the paper.
  • the envelope of the magnetic brush is polarized by a positive direct voltage of 310 volts.
  • the distance from the envelope (without toner) to the paper is approximately 0.5 mm, the thickness of the toner being 1 mm.
  • the support on which the electrophotographic paper moves is metallic and earthed.
  • the photoconductor is then discharged by lighting it using a light source 8.
  • a slit was used here. 9, arranged on the back of the electrophotographic paper extending over approximately half the width of the electrophotographic paper. This slit is illuminated using a lamp delivering 10,000 Lux arranged 3 cm from the support 1 which advances at the speed of 10 cm / s. The width of the slot is 2.5 cm.
  • the optical density of electrophotographic paper measured using a "MACBETH TP 524 DENSITOMETER" device, used in transmission with a neutral filter was 1.1. The electrophotographic paper is thus discharged only over half of its width.
  • the axis XX ′ represents the limit of the illuminated zone and of the unlit zone before fixing (the magnification used in the various photos in FIGS. 2, 3, and 4 is 22).
  • the unloaded area before fixing (which also corresponds to FIG. 3) has a very white background with very sharp halftone dots: the average optical density of this area, measured by reflection with a neutral filter is 0.24.
  • the non-discharged area before fixing (which also corresponds to FIG. 4) is almost uniform, the distinction between the background areas and the weft points being very difficult.
  • the average optical density measured is 0.41.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Fixing For Electrophotography (AREA)
  • Developing For Electrophotography (AREA)
  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
EP80401156A 1979-08-08 1980-08-06 Procédé de reproduction electrographique sur un support par développement inverse et fixage par pression Expired EP0024234B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80401156T ATE9515T1 (de) 1979-08-08 1980-08-06 Verfahren zur elektrographischen wiedergabe auf einem traeger durch umkehrentwicklung und druckfixierung.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7920264 1979-08-08
FR7920264A FR2474185A1 (fr) 1979-08-08 1979-08-08 Procede de developpement et de fixage d'une image obtenue par electrographie

Publications (2)

Publication Number Publication Date
EP0024234A1 EP0024234A1 (fr) 1981-02-25
EP0024234B1 true EP0024234B1 (fr) 1984-09-19

Family

ID=9228709

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80401156A Expired EP0024234B1 (fr) 1979-08-08 1980-08-06 Procédé de reproduction electrographique sur un support par développement inverse et fixage par pression

Country Status (8)

Country Link
US (1) US4294903A (enrdf_load_stackoverflow)
EP (1) EP0024234B1 (enrdf_load_stackoverflow)
JP (1) JPS607272B2 (enrdf_load_stackoverflow)
AT (1) ATE9515T1 (enrdf_load_stackoverflow)
CA (1) CA1140813A (enrdf_load_stackoverflow)
DE (1) DE3069221D1 (enrdf_load_stackoverflow)
DK (1) DK340580A (enrdf_load_stackoverflow)
FR (1) FR2474185A1 (enrdf_load_stackoverflow)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8102224A (nl) * 1981-05-07 1982-12-01 Philips Nv Werkwijze voor het langs elektrofotografische weg vervaardigen van een beeldscherm voor een kleurenbeeldbuis.
DE4342904C1 (de) * 1993-03-02 1995-04-27 Duma Masch Anlagenbau Abblasvorrichtung

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2965756A (en) * 1959-10-09 1960-12-20 Haloid Xerox Inc Electrostatic charging apparatus
CA953349A (en) * 1970-07-08 1974-08-20 Rca Corporation Method of electrostatic printing
US3707138A (en) * 1970-12-14 1972-12-26 Eastman Kodak Co Apparatus for transferring a developed image from a photosensitive member to a receiver
US4035750A (en) * 1975-10-14 1977-07-12 Eastman Kodak Company Electrophotographic apparatus having improved photoconductor regenerative structure and procedure
JPS52102743A (en) * 1976-02-23 1977-08-29 Olympia Werke Ag Apparatus for pressure fixing ink powder image on recording carrier
JPS53115227A (en) * 1977-03-18 1978-10-07 Hitachi Metals Ltd Electrostatic latent image developing method
JPS6049310B2 (ja) * 1977-12-27 1985-11-01 日立金属株式会社 圧力定着装置

Also Published As

Publication number Publication date
FR2474185A1 (fr) 1981-07-24
JPS607272B2 (ja) 1985-02-23
CA1140813A (fr) 1983-02-08
ATE9515T1 (de) 1984-10-15
EP0024234A1 (fr) 1981-02-25
FR2474185B1 (enrdf_load_stackoverflow) 1983-08-12
DE3069221D1 (en) 1984-10-25
JPS56101174A (en) 1981-08-13
US4294903A (en) 1981-10-13
DK340580A (da) 1981-02-09

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