US3498917A - Liquid developer for electrostatic images - Google Patents

Liquid developer for electrostatic images Download PDF

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Publication number
US3498917A
US3498917A US588576A US3498917DA US3498917A US 3498917 A US3498917 A US 3498917A US 588576 A US588576 A US 588576A US 3498917D A US3498917D A US 3498917DA US 3498917 A US3498917 A US 3498917A
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US
United States
Prior art keywords
liquid
toner
image
charge
liquid developer
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
US588576A
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English (en)
Inventor
Klaus Witter
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.)
US Philips Corp
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US Philips Corp
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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3498917A publication Critical patent/US3498917A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • 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
    • G03G13/10—Developing using a liquid developer, e.g. liquid suspension
    • 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
    • G03G9/125—Developers with toner particles in liquid developer mixtures characterised by the liquid
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/16—Developers not provided for in groups G03G9/06 - G03G9/135, e.g. solutions, aerosols
    • G03G9/18—Differentially wetting liquid developers

Definitions

  • the invention relates to a method of developing latent, electrostatic images on carriers with the use of liquids.
  • Solid developers usually consist of two powdery constituents of the same or of different granular size, which charge each other tribo-electrically. If this mixture is poured onto the charge-image to be developed the grains of a polarity opposite that of the image are retained, so that a visible picture is formed. With liquid developers the suspended toner assumes an electrostatic charge with respect to the liquid. This developing process corresponds to the phenomenon known under the name of electro phoresis.
  • the novel method of the invention obviates these disadvantages and is characterized in that two liquids are employed, which do not intermix one of which being polar and at least to some extent electrically conductive, whereas the other is highly insulating (dielectric) and forms a thin film between the layer to be developed and the polar liquid, whilst the toner material suspended in this liquid or initially contained only in the contact region of the two liquids penetrates through the thin film to the layer in accordance with the latent charge-images.
  • the novel method provides short periods of development at a low surface charge density of the electric images, a cheap space-saving construction of the developing apparatus and the possibility of using cheap, chemically simple substances.
  • the liquid 1 is polarfor example, water, glycol, glycerine, methanol and so onor formed by metallic, conducting mercury
  • the liquid 2 is highly insulating (dielectric)--for example, petrol, benzene, cyclohexane, turpentine, silicon oil, carbon tetrachloride, Freons.
  • An immersed carrier of the charge-image which consists in all electrostatic printing or copying methods of a layer 3 and a substrate 6 (paper) is wetted more strongly by the dielectric liquid 2 with an appropriate choice of the liquids.
  • the liquid 2 forms a thin film between the layer 3 and the polar liquid 1 and from an electrostatic point of view it forms the dielectric of a capacitor of a high capacity.
  • a strong electric field 5 with respect to the polar liquid 1 is produced.
  • a toner 4 which must be electrically good conducting, for example, soot, is introduced into the interface of the liquids 1 and 2, it is charged at the polar liquid 1 with a polarity opposite the charged image and penetrates through the liquid 2 towards the layer regions to be coloured.
  • the process is aided by the fact that apart from the layer 3 also the toner 4 is usually wetted more strongly by the liquid 2 than by the liquid 1 and that the energy of the process is such that conditions are favorable for the toner to be located at the interface.
  • the process consists in continuously moving the image carriers 3, 6 through an insulating liquid 2 through an interface rich in toner material in a polar, more conductive liquid 1 by means of a rotatable device 7, which is located at least partly in the liquid 1, out of the liquid phase system.
  • Various embodiments are possible (FIG. 2).
  • toner material A large quantity of toner material is introduced into the system, so that it floats in a thick layer on the liquid 1, in which it settles by sedimentation, whereas for reasons of energy it is not capable of transgressing the phase boundary.
  • a charge-image When a charge-image is dipped into the liquid 1, said process of the toner transition takes place.
  • a great quantity of toner material is carried along by the uncharged regions. During the withdrawal from the liquid 1, this material drops down and settles in the liquid 2 down to the phase boundary.
  • the current produced in the liquids by the movement of the image carrier provide a uniform toner distribution in the phase boundary. It is advisable to use fairly coarse, inorganic toners, whilst an adequate conductivity has to be ensured.
  • Such a toner has little or no emulsifying effect in the two liquids, if the interfacial tension is chosen not to be too low. Coarse toner grains and a low viscosity of the insulating liquid are conducive to the sedimentation of the toner material (and simultaneously to the toner transition).
  • the cleanness of the picture is determined essentially by the toner concentration of the upper layers of the liquid 2, so that in upward direction a concentration gradient should be maintained.
  • mercury mercury
  • the toners may have a higher specific weightfor example, various metal powders, metal oxide powders, metal sulphide powders and so on, so that the rate of sedimentation of the toner in the liquid 2 is higher.
  • the image carriers may be light-sensitive metal drums (metal plates) electrographic or electrophotographic special paper.
  • the liquid 2 may then have a higher specific weight, so that the non-inflammable, halogenized hydrocarbons, or, if desired, highly volatile, non-inflammable, non-poisonous Freons.
  • FIG. 2 For high rates of development the following structural measures may be taken (FIG. 2). There is provided a rotary device formed by a metal roller 7, immersed in the developer bath at the most by half, so that the rear side of the image carrier material 3, 6 is not wetted. The consumption of the liquid 2 is thus reduced.
  • the tank 8 is shaped in a form such that only a minimum quantity of liquid can evaporize. The consumption of liquid is, of course, determined chiefly by the adsorption at the image carrier; in the case of very high rates of passage through the liquid 2 it is advisable to provide a device for regaining said liquid (not shown in FIG. 2).
  • the electrode 9 in the neighbourhood of the transitional regions of the toner material serve to prevent the static charge of Even with light-sensitive image carriers the course of the rays or the wavelength of the light of this device may be chosen in an appropriate manner.
  • a drum which may be light-sensitive, may be employed as an intermediate carrier, from which the developed image is afterwards transferred to the definite picture carrier. In FIG. 2 the drum has to be supposed to take the place of the rotary device 7.
  • the requirements with respect to insulation capacity need not be severe.
  • the developing process is performed more rapidly than the discharge of the image by contamination with ions.
  • the liquid 2 need not be chemically pure, so that the cost may be lower.
  • the developing process is performed more rapidly than the dissolving process in the liquid 2.
  • the solubility may be chosen appropriately by mixing an inert liquid and a dissolving liquid. The developing bath is then at the same time a fixing bath.
  • a liquid developer for electrotatic images consisting essentially of a mixture of liquid mercury, an organic dielectric liquid inert to and immiscible with mercury and finely divided toner material inert to mercury, dispersed in said mixture and consisting of finely divided carbon or finely divided inorganic toners.
  • the liquid developer of claim 1 wherein the toner is selected from the group consisting of finely divided metals, metal oxides and metal sulfides inert to mercury.
  • the liquid developer of claim 2 wherein the organic liquid is selected from the group consisting of benzene, cyclohexane, turpentine, silicon oil, carbon tetrachloride and gasoline.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Liquid Developers In Electrophotography (AREA)
US588576A 1965-10-23 1966-10-21 Liquid developer for electrostatic images Expired - Lifetime US3498917A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEP0037944 1965-10-23

Publications (1)

Publication Number Publication Date
US3498917A true US3498917A (en) 1970-03-03

Family

ID=7375594

Family Applications (1)

Application Number Title Priority Date Filing Date
US588576A Expired - Lifetime US3498917A (en) 1965-10-23 1966-10-21 Liquid developer for electrostatic images

Country Status (7)

Country Link
US (1) US3498917A (da)
BE (1) BE688802A (da)
CH (1) CH487435A (da)
DE (1) DE1497190B2 (da)
GB (1) GB1170597A (da)
NL (1) NL6614680A (da)
SE (1) SE320884B (da)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3601092A (en) * 1969-02-28 1971-08-24 Ricoh Kk Developing device for wet process electrophotography
US3628981A (en) * 1969-06-09 1971-12-21 Seiji Matsumoto Liquid toner development
US3862618A (en) * 1972-11-09 1975-01-28 Xerox Corp Liquid developing apparatus for developing an electrostatic image
US3865611A (en) * 1972-11-09 1975-02-11 Xerox Corp Method for electrostatic image development employing toner and carrier supported by a conductive liquid electrode surface
US3885960A (en) * 1972-12-11 1975-05-27 Bell & Howell Co Method of development of liquid electrostatic images using an hydrophobic barrier liquid
US20040206579A1 (en) * 1998-02-26 2004-10-21 Baranda Pedro S. Tension member for an elevator
US20090107776A1 (en) * 1998-02-26 2009-04-30 Baranda Pedro S Tension member for an elevator

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5031826B1 (da) * 1970-07-20 1975-10-15

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001888A (en) * 1957-09-25 1961-09-26 Metcalfe Kenneth Archibald Method of developing an electrostatic image
US3068115A (en) * 1961-02-06 1962-12-11 Xerox Corp Electrostatic emulsion development
US3084043A (en) * 1959-05-07 1963-04-02 Xerox Corp Liquid development of electrostatic latent images
US3247007A (en) * 1960-09-06 1966-04-19 Method of developing latent electro- static images ushng solid developer body and related solvent
US3259581A (en) * 1961-11-23 1966-07-05 Australia Res Lab Liquid developer for electrostatic images
US3300410A (en) * 1961-03-13 1967-01-24 Australia Res Lab Conductive liquid developer for xerographic images
US3301698A (en) * 1961-06-08 1967-01-31 Harris Intertype Corp Method and apparatus for simultaneously developing and fixing electrostatically formed images
US3311490A (en) * 1958-09-23 1967-03-28 Harris Intertype Corp Developing electrostatic charge image with a liquid developer of two immiscible phases
US3337340A (en) * 1961-12-28 1967-08-22 Australia Res Lab Method for the reproduction of color
US3369524A (en) * 1964-08-28 1968-02-20 Lumoprint Zindler Kg Copying device for electro-photographic copying materials

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001888A (en) * 1957-09-25 1961-09-26 Metcalfe Kenneth Archibald Method of developing an electrostatic image
US3212916A (en) * 1957-09-25 1965-10-19 Commw Of Australia Method of developing electrostatic image with foam liquid developer
US3311490A (en) * 1958-09-23 1967-03-28 Harris Intertype Corp Developing electrostatic charge image with a liquid developer of two immiscible phases
US3084043A (en) * 1959-05-07 1963-04-02 Xerox Corp Liquid development of electrostatic latent images
US3247007A (en) * 1960-09-06 1966-04-19 Method of developing latent electro- static images ushng solid developer body and related solvent
US3068115A (en) * 1961-02-06 1962-12-11 Xerox Corp Electrostatic emulsion development
US3300410A (en) * 1961-03-13 1967-01-24 Australia Res Lab Conductive liquid developer for xerographic images
US3301698A (en) * 1961-06-08 1967-01-31 Harris Intertype Corp Method and apparatus for simultaneously developing and fixing electrostatically formed images
US3259581A (en) * 1961-11-23 1966-07-05 Australia Res Lab Liquid developer for electrostatic images
US3337340A (en) * 1961-12-28 1967-08-22 Australia Res Lab Method for the reproduction of color
US3369524A (en) * 1964-08-28 1968-02-20 Lumoprint Zindler Kg Copying device for electro-photographic copying materials

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3601092A (en) * 1969-02-28 1971-08-24 Ricoh Kk Developing device for wet process electrophotography
US3628981A (en) * 1969-06-09 1971-12-21 Seiji Matsumoto Liquid toner development
US3862618A (en) * 1972-11-09 1975-01-28 Xerox Corp Liquid developing apparatus for developing an electrostatic image
US3865611A (en) * 1972-11-09 1975-02-11 Xerox Corp Method for electrostatic image development employing toner and carrier supported by a conductive liquid electrode surface
US3885960A (en) * 1972-12-11 1975-05-27 Bell & Howell Co Method of development of liquid electrostatic images using an hydrophobic barrier liquid
US20040206579A1 (en) * 1998-02-26 2004-10-21 Baranda Pedro S. Tension member for an elevator
US20090107776A1 (en) * 1998-02-26 2009-04-30 Baranda Pedro S Tension member for an elevator
US9352935B2 (en) 1998-02-26 2016-05-31 Otis Elevator Company Tension member for an elevator

Also Published As

Publication number Publication date
DE1497190B2 (de) 1975-03-06
GB1170597A (en) 1969-11-12
DE1497190A1 (de) 1969-04-24
BE688802A (da) 1967-04-24
NL6614680A (da) 1967-04-24
SE320884B (da) 1970-02-16
CH487435A (de) 1970-03-15

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