Patents Assigned to Research Laboratories of Australia
  • Patent number: 7451943
    Abstract: A method of preparation of a liquid electrostatographic toner or liquid ink jet ink which includes the steps of heating a marking particle mix of particles of a resin and a colourant blend in a carrier liquid to a temperature between about the first softening point of the resin and about the second softening point of the resin, maintaining the temperature of the heated marking particle mix for a selected period of time, cooling the marking particle mix to room temperature, and mixing the marking particle mix with high shear. The particle mix can be produced by coarse grinding in a ball mill. The resultant toner or ink has an improved Newtonian like flow behaviour, improved electrical properties, reduced sedimentation and agglomeration and significantly improved optical density and reduced background. The invention also includes toners and inks produced by the method.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: November 18, 2008
    Assignee: Research Laboratories of Australia Pty Ltd.
    Inventor: Herbert Lee Marko
  • Patent number: 6939655
    Abstract: A liquid recording material containing at least a carrier liquid, a resin, a coloring agent, and a reactive silicone material, an image transfer sheet for use with the liquid recording material, and a method of fixing images, using the liquid recording material, are disclosed.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: September 6, 2005
    Assignee: Research Laboratories of Australia PTY Ltd.
    Inventors: Kazuo Tsubuko, Tsuyoshi Asami, Aiko Ishikawa
  • Patent number: 6811943
    Abstract: A toner or developer for electrostatic images including a carrier liquid and insoluble marking particles. The carrier liquid comprises or includes a polybutene. The polybutene may be present in a range of 20 to 98 percent by weight. The carrier liquid can also includes one or a blend of other carrier liquids selected from aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated solvents, silicone fluids and vegetable oils. The insoluble marking particle is present in the range of 2 to 40 percent by weight of the toner or developer.
    Type: Grant
    Filed: November 21, 2002
    Date of Patent: November 2, 2004
    Assignee: Research Laboratories of Australia Pty Ltd
    Inventor: Stephen Lansell Nicholls
  • Patent number: 6613209
    Abstract: A toner characterization cell used to determine characteristics of insoluble particles in a liquid medium. First and second electrode are spaced apart and an electric field is applied between the electrodes and a displacement current is measured. Optical density measuring devices measure the change in optical density in the cell adjacent each electrode. The characteristics are determined from the displacement current and the change in optical density. The characterizing feature may be particle mobility. The invention also relates to a method of determining the characteristics.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: September 2, 2003
    Assignee: Research Laboratories of Australia Pty Ltd.
    Inventor: Alexander Borisovich Ozerov
  • Patent number: 6579654
    Abstract: A method of preparing a liquid ink or liquid toner for printing including the steps of dispersing a monomer in a carrier fluid and a polymerization stabilizer comprising a multi or single functional group containing polysiloxane, and in situ polymerizing the monomer to form uniform polymer particles dispersed in the carrier fluid. The multi or single functional group on the polysiloxane is amino, carboxylic acid, vinyl and hydroxyl.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: June 17, 2003
    Assignee: Research Laboratories of Australia Pty Ltd
    Inventor: Herbert Lee Marko
  • Patent number: 6287741
    Abstract: A liquid toner composition for use in high viscosity electrostatic printing processes. The liquid toner comprises a non-aqueous carrier liquid which is an electrically non-conductive liquid being a silicone fluid of straight chained or cyclic configuration, a silicone fluid of cyclic configuration, a silicone fluid of branched configuration, or a combination thereof having a viscosity in the range of from 0.5 to 1,000 mPa.s, an insoluble marking particle, and a dispersion additive, the dispersion additive comprising a polysiloxane having at least one functional group comprising a radical which introduces an active site into the polysiloxane and wherein the functional group is a radical selected from the group comprising a vinyl group, a carboxylic group, a hydroxyl group, or an amine group. The particular advantage of the liquid composition is that the formation of rivulets is minimised during printing with resultant improvement in image quality.
    Type: Grant
    Filed: April 11, 2000
    Date of Patent: September 11, 2001
    Assignee: Research Laboratories of Australia Pty Ltd
    Inventor: Herbert Lee Marko
  • Patent number: 6207336
    Abstract: A liquid developing method that uses a highly-concentrated liquid developing agent to develop an electrostatic latent image. A highly-concentrated liquid developing agent with a viscosity of 100 to 1,000 mPa.s can be used. Therefore, a film of developing agent from 5 to 40 &mgr;m thick can be formed on the surface of the developing roller or developing belt and this provides a soft contact with the photosensitive member surface where the electrostatic latent image has been formed. If the surface of the photosensitive member does not have good release properties, a film of pre-wet liquid can be formed on the surface of the photosensitive member.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: March 27, 2001
    Assignee: Research Laboratories of Australia PTY Ltd.
    Inventors: Masahiko Itaya, Hiroyuki Nakagoshi, Tsutomu Sasaki, Tai Hasegawa, Toshihiro Saito, Yoshiyuki Tanaka
  • Patent number: 6174640
    Abstract: A polymer suitable for the preparation of liquid toners for developing electrostatic images and liquid toners incorporating such a polymer. The polymer is a reaction product of an epoxy resin and carrier soluble nitrogen bearing polymeric compound. The epoxy resin may be a reaction product of bisphenol A and epichlorhydrin and the carrier soluble nitrogen bearing polymeric compound may be an alkylated polyvinylpyrrolidone.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: January 16, 2001
    Assignee: Research Laboratories of Australia PTY Ltd.
    Inventor: Terence Michael Lawson
  • Patent number: 6167225
    Abstract: This invention relates to an electrostatic latent image liquid developing method and liquid developing apparatus that can prevent adhesion of toner to the non-image parts on the image bearing member and thereby prevent the occurrence of image inaccuracies. The method provides a pre-wetting process that applies pre-wet liquid to photosensitive member 10 and a developing process. In the developing process, a thin layer of a highly viscous liquid developing agent, in which toner is dispersed at a high concentration in a non-conductive liquid, is formed on the elastic developing roller 506. Developing roller 506 is rotated and, at the same time, the liquid developing agent layer on developing roller 506 is brought into contact with the pre-wet liquid layer on photosensitive member 10 in order to supply liquid developing agent to the latent image on photosensitive member 10. Thus, the toner develops the electrostatic latent image formed on photosensitive member 10.
    Type: Grant
    Filed: July 10, 1996
    Date of Patent: December 26, 2000
    Assignee: Research Laboratories of Australia Pty Ltd
    Inventors: Tsutomu Sasaki, Masahiko Itaya
  • Patent number: 6137976
    Abstract: A multi-color image formation apparatus that has multiple developed image formation devices, each corresponding to one color. Each of the developed image formation devices has a photosensitive member, charging apparatus that charges the photosensitive member, exposure apparatus that exposes the charged photosensitive member, and developing apparatus that supplies highly viscous and highly concentrated color liquid developing agent to the surface of the latent image on the photosensitive member. Each of the developed image formation devices is provided with transfer apparatus that sequentially transfers the developed images, each of which has been formed on the surface of the latent imgae on one of the photosensitive members, to the paper transported by the transfer belt and thereby forms a color image on the paper. An electrostatic latent image is formed on a photosensitive member such that a developed image corresponding to the desired print image remains on the developing agent bearing member.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: October 24, 2000
    Assignee: Research Laboratories of Australia PTY Ltd.
    Inventors: Masahiko Itaya, Tai Hasegawa, Tsutomu Sasaki
  • Patent number: 5612162
    Abstract: A composition and a method of forming a liquid developer or a constituent of a liquid developer for electrostatography comprising the steps of dispersing at least one monomer in silicone fluid and polymerizing the at least one monomer to form polymer particles in the silicone fluid. A homopolymer or a copolymer may be formed and a colorant, such as a pigment or dye, and a charge control agent may be added before or after the polymerization.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: March 18, 1997
    Assignee: Research Laboratories of Australia PTY Ltd.
    Inventors: Terence M. Lawson, Stephen L. Nicholls
  • Patent number: 5609979
    Abstract: A method of production of microparticles of a thermoplastic polymer suitable as a toner for electrostatographic processes comprising the steps of melting the material in a continuous non-solvent phase having a boiling point higher than the melting point of the thermoplastic polymer, mixing the thermoplastic polymer in the continuous phase to produce an emulsion, and cooling the emulsion to produce a dispersion of solid microparticles of the thermoplastic polymer in the continuous phase. The thermoplastic polymer may include pigments or dyes to provide colored toner particles. A surface active agent may be used to control particle size.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: March 11, 1997
    Assignee: Research Laboratories of Australia Pty Ltd.
    Inventor: Terence M. Lawson
  • Patent number: 5591557
    Abstract: A liquid developer for electrostatography comprising a silicone fluid, marker particles and a charge control agent which is soluble in the silicone fluid. The charge control agent may be an organo-metallic compound such as an organo titanate selected from tetra-2-ethyl hexyl titanate, tetra-n-butyl titanate and tetra isopropyl titanate. The organo-metallic compound may be present in a range of from 0.01 to 10% by weight of the toner particles, with a preferred range of 0.1 to 2% by weight. A colourant may also be included.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: January 7, 1997
    Assignee: Research Laboratories of Australia Pty Ltd.
    Inventors: Terence M. Lawson, Stephen L. Nicholls
  • Patent number: 4697463
    Abstract: A method for testing electrostatic developer toners which comprises applying the toner to a stationary non-magnetic sleeve (4), moving the toner along the surface of the sleeve by an array of field lines generally normal to the surface produced by a multiple magnetic roll (1) rotating within the sleeve and determining the characteristics of the toner from the pattern (15) of the spread toner by reference to a calibrated scale (9) and a stop line (5) on the surface of the sleeve.
    Type: Grant
    Filed: August 6, 1985
    Date of Patent: October 6, 1987
    Assignee: Research Laboratories of Australia Pty. Ltd.
    Inventors: Anthony N. Spooner, Luis Lima-Marques
  • Patent number: 4470350
    Abstract: A method of impact printing onto a receiving sheet on a platen by supplying powder to the sheet for pressure fixture by type face impact. The powder is temporarily held to the sheet by either electrostatic or magnetic force. In an alternate embodiment, the powder is held on the type face by electrostatic or magnetic force.
    Type: Grant
    Filed: November 15, 1982
    Date of Patent: September 11, 1984
    Assignee: Research Laboratories of Australia PTY Limited
    Inventor: Robert J. Wright
  • Patent number: 4245555
    Abstract: A system for producing lithographic printing plates by image transfer from either a right way or a wrong way reading recording member, which comprise a conductive base having first and second register means thereon the register means being arranged and positioned respectively so that the first engages and locates an image receiving member and a recording member on the base and the second engages and locates an offset member on the base, the register means being spaced apart to allow access to the first register means while the offset member is engaged on the second register means, a roller having at least a conductive core arranged to move over the base outwards from the register means and return, and means to apply an electrical field between the roller and base and to change the polarity to prevent electrostatic image transfer during the outward movement of the roller and to cause electrostatic image transfer during the return movement of the roller.
    Type: Grant
    Filed: September 11, 1978
    Date of Patent: January 20, 1981
    Assignee: Research Laboratories of Australia Pty Limited
    Inventor: Julia M. Alston
  • Patent number: 4182266
    Abstract: A system for producing lithographic printing plates by image transfer from either a right way or a wrong way reading recording member, which comprise a conductive base having first and second register means thereon the register means being arranged and positioned respectively so that the first engages and locates an image receiving member and a recording member on the base and the second engages and locates an offset member on the base, the register means being spaced apart to allow access to the first register means while the offset member is engaged on the second register means, a roller having at least a conductive core arranged to move over the base outwards from the register means and return, and means to apply an electrical field between the roller and base and to change the polarity to prevent electrostatic image transfer during the outward movement of the roller and to cause electrostatic image transfer during the return movement of the roller.
    Type: Grant
    Filed: May 23, 1977
    Date of Patent: January 8, 1980
    Assignee: Research Laboratories of Australia Pty. Limited
    Inventor: Julia M. Alston
  • Patent number: 4152151
    Abstract: A method for pressure induced development of electrostatic latent images comprising forming an electrostatic latent image on a support member and subsequently placing the image bearing surface of the member in face contact with a receiving sheet, applying a dispersion to at least one of the contacting surfaces in a first state wherein the flow properties of the dispersion are non-Newtonian and the dispersion consists of a liquid phase and of a solid phase comprising flocculated electroscopic marking particles forming a matrix sufficiently strong to prevent extraction of individual electroscopic marking particles from the matrix by electrostatic attraction, using a pressure roller to apply to the dispersion a shear stress of sufficient magnitude to convert the dispersion to a second state wherein the flow properties of the dispersion become Newtonian and the solid phase is deflocculated in the liquid phase to allow individual electroscopic marking particles to deposit in accordance with the latent image, and s
    Type: Grant
    Filed: June 9, 1975
    Date of Patent: May 1, 1979
    Assignee: Research Laboratories of Australia Pty. Limited
    Inventors: Terence M. Lawson, Blair D. Howell
  • Patent number: 3949116
    Abstract: The method of developing an electrostatic latent image contained on a surface comprising the steps of applying to a surface a dispersion in a first state wherein the flow properties of the dispersion are non-Newtonian and wherein the dispersion consists of a liquid phase and of a solid phase comprising flocculated electroscopic marking particles forming a matrix sufficiently strong to prevent extraction of individual electroscopic marking particles from the matrix and applying to the dispersion a shear stress of sufficient magnitude to convert the dispersion from the first state to a second state wherein the flow properties of said dispersion become Newtonian and wherein said solid phase is deflocculated.
    Type: Grant
    Filed: June 10, 1974
    Date of Patent: April 6, 1976
    Assignee: Research Laboratories of Australia Pty. Limited
    Inventors: Terence M. Lawson, Blair D. Howell
  • Patent number: 3944355
    Abstract: In an electrostatic copier particularly of the microfilm reader-printer type an electrically insulating member such as a polyester transport belt is provided onto which an uncharged recording sheet is fed so that no other holding means is required to position the recording sheet at the exposure station, the invention utilizing, at the site of discharging the recording sheet onto the transport belt, a conductive electrode which is interposed between recording sheet and insulating belt to allow a single corona generating device to both apply a surface charge to said recording sheet and assemble it onto the transport belt.BACKGROUND OF THE INVENTIONThis invention relates to electrostatic copiers and in particular it relates to an improved method of electrostatically charging, transporting and positioning for the purpose of exposure an electrophotographic recording member in such a copier.
    Type: Grant
    Filed: April 4, 1974
    Date of Patent: March 16, 1976
    Assignee: Research Laboratories of Australia
    Inventor: Josef Matkan