US3337340A - Method for the reproduction of color - Google Patents

Method for the reproduction of color Download PDF

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Publication number
US3337340A
US3337340A US238786A US23878662A US3337340A US 3337340 A US3337340 A US 3337340A US 238786 A US238786 A US 238786A US 23878662 A US23878662 A US 23878662A US 3337340 A US3337340 A US 3337340A
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United States
Prior art keywords
resin
overprinting
image
pigment
solvent
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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US238786A
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English (en)
Inventor
Matkan Josef
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Research Laboratories of Australia Pty Ltd
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Australia Res Lab
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Filing date
Publication date
Priority claimed from AU12804/61A external-priority patent/AU264712B2/en
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Publication of US3337340A publication Critical patent/US3337340A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/122—Developers with toner particles in liquid developer mixtures characterised by the colouring agents
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G11/00—Selection of substances for use as fixing agents
    • 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
    • G03G13/01—Electrographic processes using a charge pattern for multicoloured copies
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G8/00—Layers covering the final reproduction, e.g. for protecting, for writing thereon
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds

Definitions

  • Claim. (Cl. 96-1) This invention relates to reproduction of color by electrophotography, and particularly to the reproduction of color in such forms as to be substantially similar in hue, balance and intensity to that produced by lithographic and other mechanical printing methods and color photography.
  • electrophotographic images can be produced in any desired color by one skilled in the art, and toner formulations capable of producing images of various colors are known. It is also known to produce such images in a multiplicity of colors by the use of repetition exposure and development procedures on the same electrophotographic sheet.
  • Color printing by xerographic methods usually involves the use of a photosensitive material on a relatively conducting backing or supporting layer such as a paper or metal sheet or film, the photo-sensitive layer comprising for instance a particulate photoconductor such as zinc oxide or the like in a resin binder, such coating resin being sufficiently hardened or poiymerised that its electrical properties are not affected by environmental changes during production of the print.
  • a photosensitive material on a relatively conducting backing or supporting layer such as a paper or metal sheet or film
  • the photo-sensitive layer comprising for instance a particulate photoconductor such as zinc oxide or the like in a resin binder, such coating resin being sufficiently hardened or poiymerised that its electrical properties are not affected by environmental changes during production of the print.
  • Such a sheet is first sensitized by applying an electrical charge thereto. This may be accomplished, for example, by subjecting it to a corona discharge from a series of wires or points held at a relatively high direct current potential above a base on which the sheet is placed
  • the polarity should be such as to impart a negative potential to the photo-layer in case such photo-layer is composed of zinc oxide since this material is not capable of supporting a positive electrostatic charge.
  • the sheet is then subjected to a light pattern corresponding to the requirements of the first color to be applied, and after this exposure the sheet is developed in a dish or bath or by means of some other device containing the liquid toner dispersion of the appropriate color. It is preferable to dry the sheet after this development step as this allows the first deposited image to become sufiiciently adherent to the photosurface to enable it to remain in position during subsequent handling.
  • Subsequent colors are deposited in turn by repetition of the charge, expose, develop and dry cycle, the exposure step in each instance imposing the correct light pattern corresponding with the particular color being reproduced at that time.
  • the successive images are placed in register with each other using a balanced set of compatible, overprinting toners, the resultant image will be substantially similar to that which would be produced by a mechanical printing using the same separations and inks corresponding in hue to the toners used.
  • a problem however in overprinting xerographically is that the developers tend to affect the charging characteristic and bleeding away of the charge on the photoconductor surface and therefore while the first color can be put down in the normal manner, this color can then modify the charge which different areas can take when preparing the photoconductor for the application of the second color, the problem being intensified when an attempt is made to charge through the first two colors in preparation for the application of a third color.
  • the object of this invention is to provide a form of developer which will be as close as is reasonably possible to mechanical overprinting, and we have found that this can be achieved by closely regulating the quantity of insulating matter such as resin which is used in conjunction with the pigments in the developer, it having been found by us that if there is sufiicient of such insulating resin present to just cover the pigment surface, the insulating surface formed on the developed image will be capable of supporting a charge, while the proximity of the photoconductor to the surface allows the charge to be bled away under the influence of light.
  • such resins being used in a quantity which is so balanced in relation to the pigment that sufficient resin exists in excess of the quantity required to wet the pigment and to fill the voids between the deposited particles to form an insulating film at the pigment surface or alternatively such required resin film may be subsequently placed thereon to be then capable of supporting an electrostatic charge but not to the extent that such charge could not be bled away when the photoconductor surface beneath the resin is subjected to light.
  • This present invention therefore embodies the method and means for the production and use of 'toners of various colors capable of simulating the hue, intensity transparency, and overprinting characteristics of lithographic, gravure and letterpress inks, when such toners are used under controlled conditions as herein defined.
  • the image areas must contain an insulating component either within the image forming pigment structure or as a layer over the image, such component being capable of supporting an electrostatic charge in case the surface is recharged for the subsequent color step.
  • an insulating component which is preferably a resin (termed from now on overprinting resin) is the only medium capable of supporting a charge if the image is re-charged with the purpose of depositing another color which has to overlap the previous color.
  • An image formed by a conductive pigment can be rendered sufliciently insulating so as to be capable of supporting a charge by the following methods:
  • the overprinting resin must be present with the pigment in dispersed form in a quantity such that there is suffi cient resin for adequate charge holding.
  • the co-deposited overprinting resin acts as a binder for the pigment, fills the image structure and acts as key for further overprinting resin quantities which may be deposited later in some other form.
  • the overprinting resin can be deposited over the conductive image by dipping the print containing the conductive image in a solution of the overprinting resin in a non-polar solvent of adequate insulating properties such as for instance a volume resistivity greater than 10 ohm. cm. and a dielectric constant preferably less than 3.0.
  • the image is developed in a liquid containing only dispersed pigment or pigment and some dispersing medium and then it is removed from the developer liquid and placed into the overprinting resin solution. There is still some charge left on the image areas so that in addition to an overall cover, preferential resin deposition takes place in image areas.
  • the overprinting resin can be deposited by dipping the print containing the conducting image in an overprinting resin solution in order to obtain an overall resin coating.
  • the image is developed in a vehicle containing the pigment dispersion or the pigment and some dispersing medium, the print is dried after developing and then dipped in the overprinting resin solution.
  • the concentration of overprinting resin solution in (b) and (c) must be such that the resin layer over non-image areas is not excessive so that no noticeable increase of charge holding capacity with consequent decrease in photoconductivity of the zinc oxide is caused in the imagefree or background areas.
  • the deposited layer over the image areas must be capable of supporting a charge over the conductive pigment structure yet it must also be capable of permitting such charge to leak away when the zinc oxide layer underneath the image is exposed to light in areas where no overprint is desired.
  • a smooth overprinting resin overall coverage can be obtained in (b) and (c) if to the overprinting resin solution a weaker solvent is added which acts as a diluent and promotes solvent release by a fast rate of evaporation, or if a weaker solvent is added which acts as a differential solvent causing resin precipitation upon evaporation of the true solvent, such weak solvent having a slower rate of evaporation than the true solvent.
  • the resin layer can be applied by means other than dipping, such as by spraying, by electrostatic deposition, by wet roller, in form of a contact adhesive, from a liquid wedge applicator, etcetera.
  • the overprinting resin used in (b) and (c) must of course be compatible with the dispersing medium used for the pigment in the developing vehicle and it must be compatible with any different overprinting resin used with preceding or subsequent colors.
  • the overprinting resin should be of fast drying type and of fast solvent releasing type. In dried form it should not be attacked, swelled or removed by the solvent action of the subsequent vehicles. When dried this overprinting resin should have such electrical properties as hereinbefore described that it is capable of supporting a charge adequate to attract pigment or other particulate matter for the formation of images of the desired intensity.
  • any vehicle in which an image rendered insulating by such overprinting resin is to be developed should be weaker in solvent power than the liquid in which the overprinting resin is dissolved, whether or not such overprinting resin solution contains a diluent or a differential solvent, and in view of this, the liquid vehicles should be progressively weaker in solvent power, or at least all vehicles subsequently applied to an image containing an overprinting resin insulator should be of such solvent power that the overprinting resin coating previously applied is not softened by such subsequently applied liquid.
  • This invention is preferably based on the following sequence of colors: blue, red, black and yellow, and in view of this, the formulations appearing herein and the process as described is arranged for the above sequence but this is not to limit the invention in any way as it is possible to adjust the resin solution to allow a different color sequence.
  • An electrophotographic sheet carrying a surface coating of resin-held photoconductive particles is prepared by any known method.
  • the resin which anchors the photoconductors should be impervious to and resistant to solution in the liquid used for purposes of development and washing.
  • the resin may be made resistant by prolonged curing at temperatures such as P. which do not char the paper on which the coating is placed or if the backing is of metal or other heat-resistant material then curing may be carried out in a shorter time at the recommended curing temperature for the resin.
  • the following photoconductive coating can be used in this process:
  • the ingredients can be milled together, diluted if required, and then deposited on a relatively conducting support by any known coating method.
  • Example I This example illustrates the first embodiment of this invention where a relatively conducting pigment is dispersed in a liquid vehicle containing the overprinting resin in solution.
  • Four toners are prepared as follows:
  • Red developer 100 grams of the pigment Para red, or Toluidine red or Lithol red, having a mean particle diameter of approximately 0.1 micron, is dispersed with grams of Beckosol Solution 1352 in for instance Shell solvent X55 in a similar way to the blue pigment.
  • the electrophotographic sheet is subjected to a corona discharge to produce on it a uniform electrostatic charge of the order of 200 to 400 volts.
  • the charged sheet is subjected to exposure to an image produced by filtering the colored image with an orange filter or by contact printing from a black and white separation transparency as it is well known to do in the printing industry, in this case to the blue separation.
  • This image is then developed in a dish of blue developer for 30 seconds and then washed in a poor solvent such as Shell X4 solvent or in iso-octane, or Freon 113.
  • the image so obtained is then dried oif by subjecting it to an air blast or by suspending it in the air for 2 minutes, when the ambient temperature is 70 F. or higher, in order that such dried resin film should be rendered sufiiciently insoluble in the vehicle used for subsequent colors.
  • the sheet is then re-charged by once again exposing it to the corona discharge, producing on its surface another charge which resides over the whole of the previous image.
  • the sheet is then exposed to a green filtered image or to a red separation, and the result is developed in the red developer of Example 1.
  • the image is then washed and dried as previously described for the blue image.
  • Example II This example illustrates the second embodiment of this invention (Case b) where an overprinting resin layer is deposited by placing the image after color developing into the overprinting resin solution.
  • toner concentrates containing pigments and dispersing media are prepared as follows: a (I Blue toner concentrate Grams Heliogen Blue G pigment 20 Magnesium carbonate l0 Paralac RPlO resin 80 Cold blend ingredients and mill. Magnesium carbonate has been incorporated to obtain a certain color value.
  • the overall solvent power of this rinsing liquid is smaller than that of the liquid vehicle in which the blue image has been developed.
  • the red concentrate is dispersed in Shell solvent X55 and is used for development in this form but the rinsing operation after development is carried out in a liquid comprising one part of 5% Pentacite P423 resin solution in cyclohexane to two parts of Shell solvent X55.
  • the black development step is carried out in a dispersion of the black toner concentrate in Shell solvent X55 and the rinsing operation is carried out in the same manner as for the red color.
  • the yellow development step is carried out in a dispersion of the yellow toner concentrate in n-heptane or Shell solvent X4, both of which are poorer solvents than Shell solvent X55.
  • the invention aims to ensure that there is suflicient resin present to maintain the surface charge after each development and that as one particular embodiment of this invention lower solvent power liquids are used as vehicles for toners which have to be deposited to obtain overprinting effect on to previously deposited images because such lower solvent power liquids are not capable of attacking or dissolving the overprinting resin layer which carries the surface charge.
  • Example 111 This example illustrates the third embodiment of this invention (case c) where an overprinting resin layer is deposited by dipping or other means on to a developed and dried image.
  • the four developers are made up merely by dispersing pigment in the desired carrier liquid with the aid of a wetting agent such as iso-propyl alcohol, oleic acid, cyclohexane, stearic acid, lauric acid, myristic acid or the like or other well known methods of dispersing pigments in solvents of adequate volume resistivity used in the paint and ink industries.
  • a wetting agent such as iso-propyl alcohol, oleic acid, cyclohexane, stearic acid, lauric acid, myristic acid or the like or other well known methods of dispersing pigments in solvents of adequate volume resistivity used in the paint and ink industries.
  • the invention consists of developing the colors in the sequence and manner already described but the images are dried after each development. and then dipped in or contacted by some other means with a solution of resin in a suitable solvent. It is important to distinguish between having the resin in suspension and having it in solution. Examples of the resin solutions which may be used in this embodiment
  • the dry pigments dispersed in the carrier liquid and used to form an image then selectively adsorb resin from the resin solution and so enhance charge holding capacity.
  • a convenient method of assessing the efiiciency of the resin solutions and their effect on overprinting is to dip one half of a sheet of the electrophotographic material in the solution and dry it as would be done when a picture is being produced. This dipped and dried sheet is then charged and exposed to a convenient pattern which covers both the dipped and undipped areas. The result is developed and the difference between the areas is noted.
  • Beckosol Solution 1352 is an isophthalic long oil alkyd resin based on semi-drying oil, 60% oil length, acid value 3-6, specific gravity 0.940 (solution) dissolved in Mineral Spirits, 60% non-volatile matter.
  • Paralac RPLO- is a long oil alkyd resin based on linseed oil, acid value 512, specific gravity 1.034.
  • Pentacite P-423- is a pentaeryth-ritol resin, melting range 121132 C., acid value 20-30, specific gravity 1.05 1.15.
  • Silicone Resin 804- is a silicone protective coating resin, 60% resin solids dissolved in toluene, specific gravity 1.05-1.07.
  • Epidene E168- is an epoxy ester resin based on tall oil 50% oil length, acid value 6, supplied as a 50% solution in an aromatic solvent (such as toluene), specific gravity 0.96-0.97 (solution).
  • Superbeckacite 2100 is a pure phenolic oil reactive resin, melting range 129146 C., specific gravity 1.07, 100% non-volatile matter.
  • Pentarol 1- is an unmodified pentaerythritol ester of rosin
  • Vandene M 66 is a resin modified maleic resin, melting range 100115 0, acid value -20, specific gravity 1.10, 100% non-volatile matter.
  • Shell X4 petroleum fraction, boiling range 5870 C.
  • a wet method of developing multiple colors by the overprinting of multiple electrostatic images on a single electrophotographic sheet comprising:
  • each bonding medium liquid vehicle for each developer sequence being substantially weaker in solvent power than the liquid vehicle in which the overprinting chargeable bonding medium being developed is contained

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Liquid Developers In Electrophotography (AREA)
  • Color Electrophotography (AREA)
US238786A 1961-12-28 1962-11-19 Method for the reproduction of color Expired - Lifetime US3337340A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU12804/61A AU264712B2 (en) 1961-12-28 Electrophotographic method and means forthe reproduction of colour

Publications (1)

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US3337340A true US3337340A (en) 1967-08-22

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US238786A Expired - Lifetime US3337340A (en) 1961-12-28 1962-11-19 Method for the reproduction of color

Country Status (7)

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US (1) US3337340A (fr)
BE (1) BE626695A (fr)
CH (1) CH419834A (fr)
DE (1) DE1303188B (fr)
GB (1) GB1030166A (fr)
NL (1) NL287089A (fr)
SE (1) SE308665B (fr)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3419411A (en) * 1963-09-06 1968-12-31 Australia Res Lab Method for the transfer of developed electrostatic images using a lattice forming substance
US3475169A (en) * 1965-08-20 1969-10-28 Zenith Radio Corp Process of electrostatically screening color cathode-ray tubes
US3489557A (en) * 1966-03-16 1970-01-13 Zenith Radio Corp Process of electrostatically screening a color cathode-ray tube
US3498917A (en) * 1965-10-23 1970-03-03 Philips Corp Liquid developer for electrostatic images
US3515548A (en) * 1966-03-16 1970-06-02 Zenith Radio Corp Charging process for electrostatic screening of color tubes
US3620722A (en) * 1967-09-18 1971-11-16 Supply Australia Sensitized developers for electrophotography and electroradiography
US3775106A (en) * 1970-08-28 1973-11-27 Fuji Photo Film Co Ltd Electrophotographic process
US3836361A (en) * 1971-09-30 1974-09-17 Commw Of Au Care Of The Secret Method of developing an electrophotographic image with a bias field
US3870644A (en) * 1969-02-10 1975-03-11 Ricoh Kk Liquid developer for plural-color electrophotography
US3907693A (en) * 1973-05-21 1975-09-23 Rank Xerox Ltd Liquid developer for electrophotography
US3963486A (en) * 1973-05-21 1976-06-15 Rank Xerox Ltd. Electrophotographic imaging process employing epoxy-ester containing liquid developer
US3972611A (en) * 1970-03-18 1976-08-03 Canon Kabushiki Kaisha Apparatus for transferring images produced by liquid developer
US3985560A (en) * 1969-08-21 1976-10-12 Xerox Corporation Migration imaging member with fusible particles
US4093534A (en) * 1974-02-12 1978-06-06 Plessey Handel Und Investments Ag Working fluids for electrophoretic image display devices
EP0221451A1 (fr) * 1985-10-24 1987-05-13 Stork Colorproofing B.V. Procédé de fixage d'images pour l'électrostatographie à couleurs
US5069995A (en) * 1989-05-23 1991-12-03 Commtech International Management Corporation Stain elimination in consecutive color toning
US5262259A (en) * 1990-01-03 1993-11-16 Minnesota Mining And Manufacturing Company Toner developed electrostatic imaging process for outdoor signs
US5342720A (en) * 1993-04-28 1994-08-30 Minnesota Mining And Manufacturing Company Color proofing element and process for making the same
EP0706891A2 (fr) 1994-10-13 1996-04-17 Imagine Ltd. Appareil et procédés pour l'impression numérique sans impact
US20030186158A1 (en) * 2002-03-21 2003-10-02 Samsung Electronics Co., Ltd. Electrophotographic imaging method
US20040063017A1 (en) * 2002-07-27 2004-04-01 Samsung Electronics Co., Ltd Single layered electrophotographic photoreceptor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2907674A (en) * 1955-12-29 1959-10-06 Commw Of Australia Process for developing electrostatic image with liquid developer
US3057720A (en) * 1959-05-04 1962-10-09 Xerox Corp Xerographic color reproduction
US3060020A (en) * 1958-03-20 1962-10-23 Rca Corp Method of electrophotographically producing a multicolor image
US3076722A (en) * 1959-04-29 1963-02-05 Rca Corp Electrostatic printing
US3081263A (en) * 1956-12-21 1963-03-12 Secretary Of The Dept Of Suppl Precipitation of particulate or molecular materials in electrostatic developing
US3241957A (en) * 1961-06-08 1966-03-22 Harris Intertype Corp Method of developing electrostatic images and liquid developer

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2907674A (en) * 1955-12-29 1959-10-06 Commw Of Australia Process for developing electrostatic image with liquid developer
US3081263A (en) * 1956-12-21 1963-03-12 Secretary Of The Dept Of Suppl Precipitation of particulate or molecular materials in electrostatic developing
US3060020A (en) * 1958-03-20 1962-10-23 Rca Corp Method of electrophotographically producing a multicolor image
US3076722A (en) * 1959-04-29 1963-02-05 Rca Corp Electrostatic printing
US3057720A (en) * 1959-05-04 1962-10-09 Xerox Corp Xerographic color reproduction
US3241957A (en) * 1961-06-08 1966-03-22 Harris Intertype Corp Method of developing electrostatic images and liquid developer

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3419411A (en) * 1963-09-06 1968-12-31 Australia Res Lab Method for the transfer of developed electrostatic images using a lattice forming substance
US3475169A (en) * 1965-08-20 1969-10-28 Zenith Radio Corp Process of electrostatically screening color cathode-ray tubes
US3498917A (en) * 1965-10-23 1970-03-03 Philips Corp Liquid developer for electrostatic images
US3489557A (en) * 1966-03-16 1970-01-13 Zenith Radio Corp Process of electrostatically screening a color cathode-ray tube
US3515548A (en) * 1966-03-16 1970-06-02 Zenith Radio Corp Charging process for electrostatic screening of color tubes
US3620722A (en) * 1967-09-18 1971-11-16 Supply Australia Sensitized developers for electrophotography and electroradiography
US3870644A (en) * 1969-02-10 1975-03-11 Ricoh Kk Liquid developer for plural-color electrophotography
US3985560A (en) * 1969-08-21 1976-10-12 Xerox Corporation Migration imaging member with fusible particles
US3972611A (en) * 1970-03-18 1976-08-03 Canon Kabushiki Kaisha Apparatus for transferring images produced by liquid developer
US3775106A (en) * 1970-08-28 1973-11-27 Fuji Photo Film Co Ltd Electrophotographic process
US3836361A (en) * 1971-09-30 1974-09-17 Commw Of Au Care Of The Secret Method of developing an electrophotographic image with a bias field
US3963486A (en) * 1973-05-21 1976-06-15 Rank Xerox Ltd. Electrophotographic imaging process employing epoxy-ester containing liquid developer
US3907693A (en) * 1973-05-21 1975-09-23 Rank Xerox Ltd Liquid developer for electrophotography
US4093534A (en) * 1974-02-12 1978-06-06 Plessey Handel Und Investments Ag Working fluids for electrophoretic image display devices
EP0221451A1 (fr) * 1985-10-24 1987-05-13 Stork Colorproofing B.V. Procédé de fixage d'images pour l'électrostatographie à couleurs
US5069995A (en) * 1989-05-23 1991-12-03 Commtech International Management Corporation Stain elimination in consecutive color toning
US5262259A (en) * 1990-01-03 1993-11-16 Minnesota Mining And Manufacturing Company Toner developed electrostatic imaging process for outdoor signs
US5342720A (en) * 1993-04-28 1994-08-30 Minnesota Mining And Manufacturing Company Color proofing element and process for making the same
EP0706891A2 (fr) 1994-10-13 1996-04-17 Imagine Ltd. Appareil et procédés pour l'impression numérique sans impact
US20030186158A1 (en) * 2002-03-21 2003-10-02 Samsung Electronics Co., Ltd. Electrophotographic imaging method
US6884559B2 (en) 2002-03-21 2005-04-26 Samsung Electronics Co., Ltd. Electrophotographic imaging method
US20040063017A1 (en) * 2002-07-27 2004-04-01 Samsung Electronics Co., Ltd Single layered electrophotographic photoreceptor

Also Published As

Publication number Publication date
DE1303188B (fr)
GB1030166A (en) 1966-05-18
BE626695A (fr)
CH419834A (fr) 1966-08-31
NL287089A (fr)
SE308665B (fr) 1969-02-17

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