Electrostatic Image Transfer Patents (Class 430/48)
  • Patent number: 4336306
    Abstract: An electrostatic imaging sheet wherein one side of the sheet, e.g. paper, is electrically conductive and the other side of the sheet has a continuous dielectric layer comprising a mixture of a smectite clay e.g. a synthetic hectorite swelling clay and an electrically insulating polymer, preferably in particle form. The dielectric layer may comprise a layer of a smectite clay which forms a barrier between the electrically conductive layer and the layer of insulating polymer.The invention is also a dielectric coating composition comprising a mixture of electrically insulating polymer in aqueous dispersion and a water dispersible smectite clay.The mixture of polymer and water dispersible smectite clay, preferably form a colloidal suspension, and the amount of smectite clay in the composition is preferably in the range 0.5 to 5% by weight of the composition excluding inorganic filler.
    Type: Grant
    Filed: November 13, 1979
    Date of Patent: June 22, 1982
    Inventor: Adrian N. Fellows
  • Patent number: 4330607
    Abstract: A method for forming an electrostatic latent image usable to produce images free from fog and "gooseflesh" non-uniformity wherein an electrostatic recording medium placed between two electrodes and a photoconductive layer is illuminated in a first step while a voltage less than the minimum threshold recording voltage is applied across the electrodes and then exposed in a second step to an optical image while a voltage higher than the minimum threshold recording voltage is applied across the electrodes.
    Type: Grant
    Filed: August 28, 1979
    Date of Patent: May 18, 1982
    Assignee: Nippon Electric Co., Ltd.
    Inventor: Akiyoshi Kouno
  • Patent number: 4318972
    Abstract: An electrostatic latent image residing on an electrically insulating surface used to induce a similar image on a sectionally conductive member by bringing one surface of the sectionally conductive member into proximity with the latent image while the opposite surface of the sectionally conductive member is brought to ground potential. The sectionally conductive member is then removed from proximity with the latent image. To prevent electrical breakdown during removal, a grounded electrode is placed adjacent the surface of the sectionally conductive member opposite the latent image but separated from the sectionally conductive member by a thin electrically insulating layer. A latent image is thus formed on the sectionally conductive member which can be developed by conventional means such as with electroscopic materials well known in the xerographic art.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: March 9, 1982
    Assignee: Xerox Corporation
    Inventor: James M. Hardenbrook
  • Patent number: 4311776
    Abstract: An electrophotographic copying method in which there are employed a photosensitive member including a photoconductor layer backed by a conductive electrode and a dielectric layer backed by a conductive electrode comprises the steps of positioning the members with the layers in face-to-face virtual contact and while so positioned applying a voltage of a first polarity between the electrodes under dark conditions to cause gaseous discharges in the gaps between the layers and the charging of the dielectric layer and short circuiting the electrodes while illuminating the photoconductive layer until the electric field therein is zero, and then applying a voltage of reverse polarity between the electrodes while exposing the photoconducted layer to a light image to produce an electrostatic latent image thereof on the dielectric layer which is then separated from the photoconductor layer and the latent image developed and transferred to copy paper.
    Type: Grant
    Filed: April 9, 1979
    Date of Patent: January 19, 1982
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Kuniki Seino, Yoshihiro Ozaki
  • Patent number: 4311777
    Abstract: A method of producing an electrostatic latent image of an original includes the successive steps of positioning of face-to-face virtual contact a photoconductor layer superimposed on a conductive backing electrode and a dielectric layer superimposed on another conductive backing electrode, applying a direct current voltage of a first polarity between the electrodes of a value to produce gas discharges between the layers to charge the dielectric layer while the photoconductor layer is unexposed to any light, short circuiting the electrodes while exposing the full surface of the photoconductor layer to light until the electric field across the photoconductor layer is substantially zero and applying a voltage between the electrodes at a polarity opposite to the first polarity while exposing the photoconductor layer to the light image of an original.
    Type: Grant
    Filed: April 2, 1979
    Date of Patent: January 19, 1982
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Kuniki Seino, Yoshihiro Ozaki
  • Patent number: 4309497
    Abstract: In an electrically activatable recording element, such as one comprising an electrically conductive support having thereon, in sequence: (a) a polymeric electrically active conductive (EAC) layer, (b) an electrically activatable recording layer comprising (A) a dye-forming coupler, and (B) an oxidation-reduction combination comprising (i) an organic silver salt oxidizing agent, such as a silver salt of a 1,2,4-mercaptotriazole derivative, with (ii) a reducing agent which, in its oxidized form, forms a dye with the dye-forming coupler, (c) a photoconductive layer separated from (b) by an air gap of up to 20 microns, and (d) an electrically conductive layer; improvements are provided by means of a polymeric EAC layer (a) comprising a halogen containing polyester, such as poly(2,2'-oxydiethylene:2,2'-dimethyl 1,3-propylene 50:50-2,5-dibromoterephthalate) and poly(ethylene:2,2-dimethyl-1,3-propylene 50:50-2,5-dibromoterephthalate).
    Type: Grant
    Filed: June 13, 1980
    Date of Patent: January 5, 1982
    Assignee: Eastman Kodak Company
    Inventors: Mark Lelental, Mohammad A. Sandhu
  • Patent number: 4282297
    Abstract: Charge transfer imaging method and apparatus using a photoreceptor assembly. The assembly, which is formed by the interposition of a semiconducting substrate between a photoreceptor and a conducting base member, is used to transfer an image to a dielectric member with reduced image degradation.
    Type: Grant
    Filed: April 14, 1980
    Date of Patent: August 4, 1981
    Assignee: Dennison Manufacturing Company
    Inventor: Richard A. Fotland
  • Patent number: 4281052
    Abstract: An image-forming member for forming a metal grain image of the type containing a reducible metal compound which is able to isolate metal from it when reduced, and a reducing agent being capable of reducing the metal compound so that there may be formed a metal grain image by the metal isolated from the metal compound at the portion of the member subjected to the action of energy for producing a metal grain image-forming ability and thermal energy is characterized by the provision of a capturing means which is capable of capturing by-product produced from the metal compound upon the isolation of the metal from the metal compound.
    Type: Grant
    Filed: February 28, 1980
    Date of Patent: July 28, 1981
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Ito, Ichiro Endo, Shigeru Ohno
  • Patent number: 4277551
    Abstract: An electrophotographic plate comprising a conductive substrate, a photoconductive-insulative layer overlaying the substrate and a transparent, electrically active, organic, electron transport layer overlaying the photoconductive-insulative layer in which the photoconductive layer comprises a Se--Te or Se--As mixture in the range of 90-97.5 atomic percent Se or 60-97.5 atomic percent, respectively, and wherein the thicknesses of the photoconductive layer and transport overlayer range between 40 to 100 micrometers and 1 to 5 micrometers, respectively.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: July 7, 1981
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Terry J. Sonnonstine, Kenneth G. Kneipp
  • Patent number: 4276829
    Abstract: The method of forming a charge-image on a charge-retaining object by applying an electrical image-activating energy and a mechanical image-activating energy in a manner to result in the functional dependence of the charge density of the consequent charge-image to the magnitudes of the image-activating energies and to the length of the activating time period, enabling the charge-image or the subsequent visible image to have a uniform desired level of desired density, controlled multiple levels of density, controlled continuously varying density, or a combination thereof. It also enables the trading off of charge density for a lower image-activating voltage and the trading off of charge-imaging speed for higher charge density. The resulting image is of high fidelity to the original.
    Type: Grant
    Filed: September 20, 1979
    Date of Patent: July 7, 1981
    Inventor: Wu Chen
  • Patent number: 4273845
    Abstract: A heat-developable photosensitive material for producing an electrostatic printing master having improved electrostatic characteristics comprises a support, an organic silver salt, a reducing agent, and a binder.
    Type: Grant
    Filed: February 28, 1980
    Date of Patent: June 16, 1981
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hajime Kobayashi, Yasuhiro Yano, Ichiro Endo
  • Patent number: 4273844
    Abstract: A heat-developable photosensitive member for forming an electric printing master comprises a support, an organic silver salt layer containing an organic silver salt, a halide and a toning agent dispersed in a binder, and a surface protecting layer or a particular surface, and a reducing agent is contained in at least one layer of the organic silver salt layer and a layer adjacent to the organic layer.
    Type: Grant
    Filed: August 9, 1978
    Date of Patent: June 16, 1981
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hajime Kobayashi, Yasuhiro Yano, Ichiro Endo
  • Patent number: 4268595
    Abstract: An electrostatic recording material comprising a support having formed thereon a dielectric layer composed of a terpolymer consisting of (a) methacrylic acid, (b) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, and (c) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, wherein monomer (b) and monomer (c) are different and at least one of the monomers (b) and (c) is an acrylic acid ester containing at least 11 carbon atoms or a methacrylic acid ester containing at least 8 carbon atoms, and a method for producing an electrostatic recording material, which comprises converting such a terpolymer to a water-soluble or water-emulsifiable salt of the terpolymer in which about 20 to 100 mol% of the carboxyl groups present form a salt with ammonia and/or a volatile amine,
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: May 19, 1981
    Assignee: Copyer Co., Ltd.
    Inventors: Kazuharu Katagiri, Shozo Ishikawa, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4259424
    Abstract: An improved heat-developable photosensitive material is disclosed which comprises an infrared rays-absorbing layer provided in contact with or adjacent to a layer comprising a reducible organic silver salt.
    Type: Grant
    Filed: February 5, 1979
    Date of Patent: March 31, 1981
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ichiro Endo, Hajime Kobayashi, Toshiyuki Komatsu, Shigeru Ohno
  • Patent number: 4258073
    Abstract: A first method of revealing a fingerprint involves the charging of the surface bearing the fingerprint to a high electric potential and applying finely divided carbon to the charged surface to form a pattern thereon corresponding to the fingerprint.The finely divided carbon may be dusted or sprayed on or may be in suspension in a dielectric liquid into which the charged surface is introduced.In another method the surface is charged while submerged in the dielectric liquid, under the action of an electric field in the dielectric.In another method an electrically charged sheet is brought into contact with a surface bearing a fingerprint and after being removed, the charged sheet has applied to its surface finely divided carbon which adheres thereto depending on the charge pattern remaining thereon after contact with the fingerprint.The pattern of finely divided carbon can be fixed in position by applying thereover a transparent protective layer.
    Type: Grant
    Filed: February 28, 1979
    Date of Patent: March 24, 1981
    Inventor: John M. Payne
  • Patent number: 4220699
    Abstract: A method whereby a large number of copies can be produced from a single electrostatic latent image formed on one of a dielectric member, an insulating member or photoconductive member by developing and printing the image by transfer printing in successive operations. The absolute value of a bias voltage impressed on the developing device in developing the electrostatic latent image is gradually reduced until the number of copies produced reaches a specific level, and then progressively increased as the number of copies produced increases for producing copies in numbers which exceed the specific level, whereby copies of a number greater than the number of the specific level can be produced from the same electrostatic latent image.
    Type: Grant
    Filed: May 17, 1978
    Date of Patent: September 2, 1980
    Assignee: Ricoh Co., Ltd.
    Inventors: Tsutomu Ishida, Takehiko Iwaoka
  • Patent number: 4207100
    Abstract: Disclosed is a process for forming an electrostatic latent image on a recording element having a dielectric layer superposed on a conductive electrode. In the first step of this process, the recording element and a xerographic sensitive element having a photoconductive layer also superposed on a conductive electrode are charged with the same polarity. In the second step, the photosensitive element is brought into virtual contact with the recording element so that the charged surface of the photoconductive layer in the photosensitive element is in face-to-face relationship with the charged surface of the dielectric layer in the recording element.
    Type: Grant
    Filed: May 9, 1978
    Date of Patent: June 10, 1980
    Assignee: Teijin Limited
    Inventors: Sadao Kadokura, Kazuhiko Honjo, Kazuhiro Kamei
  • Patent number: 4195927
    Abstract: An electrophotographic system employing double image transfer. A photoconductive member is charged and exposed to form a latent electrostatic image, which is then transferred to a drum with a durable dielectric coating. The latent electrostatic image is subsequently toned and transferred by pressure to a recording medium, with or without simultaneous pressure fixing.
    Type: Grant
    Filed: January 30, 1978
    Date of Patent: April 1, 1980
    Assignee: Dennison Manufacturing Company
    Inventors: Richard A. Fotland, Jeffrey J. Carrish