Patents Assigned to Mita Industrial Company
  • Patent number: 4315064
    Abstract: Disclosed is an electrostatic photographic copying process comprising causing a substrate carrying an electrostatic latent image thereon to fall in contact with a magnetic brush of a one-component type magnetic developer to effect development of the electrostatic latent image and electrostatically transferring the formed image of the developer onto a transfer sheet, wherein a magnetic developer having an electrostatic capacity of 7.8 to 9.8 PF (picofarad) as determined under conditions of an electrode spacing of 0.65 mm, an electrode sectional area of 1.43 cm.sup.2 and an electrode load of 105 cm.sup.2 and a dielectric constant of 4 to 5 as determined under the above conditions is used as the one-component type magnetic developer.
    Type: Grant
    Filed: November 28, 1979
    Date of Patent: February 9, 1982
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Takashi Teshima
  • Patent number: 4314018
    Abstract: An electrophotograhic copying process forms an electrostatic latent image on the surface of a photosensitive member, developes the image by applying a monocomponent developer to the latent image to form a toner image, transfers the thus formed toner image by contacting a receptor sheet with the photosensitive member to transfer the toner image to the surface of the receptor sheet, fixes the toner image onto the surface of the receptor sheet, eliminates electrostatic charge from the photosensitive member by irradiating the surface of the photosensitive member with an electrostatic eliminating lamp after the toner image has been transferred to the receptor sheet, and cleans the surface of the photosensitive member by removing the developer remaining on the surface thereof.
    Type: Grant
    Filed: October 26, 1979
    Date of Patent: February 2, 1982
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Shoji Matsumoto, Toshikazu Matsui, Toshimitsu Ikeda, Nobuhiko Kozuka, Hitoshi Nishihama, Tatsuo Aizawa
  • Patent number: 4311779
    Abstract: Disclosed is a one-component type magnetic developer which comprises a binder medium and 45 to 65% by weight, based on the total developer, of fine particles of a magnetic material dispersed in the binder medium, the binder medium comprising a homopolymer of an aromatic vinyl monomer or a copolymer of (a) at least one aromatic vinyl monomer with (b) at least one mono- or di-ethylenically unsaturated monomer other than the aromatic vinyl monomer and having a weight average molecular weight of 75,000 to 150,000, wherein the electrostatic capacity as determined under conditions of an electrode spacing of 0.65 mm, an electrode sectional area of 1.43 cm.sup.2 and an electrode load of 105 g/cm.sup.2 is 7.8 to 11.7 PF (picofarad), the dielectric constant is 4 to 6 as determined under the above conditions and the electric resistance is at least 5.times.10.sup.13 .OMEGA.-cm as determined under the above conditions.
    Type: Grant
    Filed: November 28, 1979
    Date of Patent: January 19, 1982
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Takashi Teshima
  • Patent number: 4295731
    Abstract: An electrostatic copying apparatus has a copying paper wound in a roll-like form, and an endless drive cable loop is wrapped about two drive reels rotated in one direction so as to cause part of an optical device or an original document carrier to travel reciprocally during a copying operation. Each copying operation mode, such as copying paper feeding, exposure, and copying paper cutting, is timed by means of mechanical constructions including a moving member to cause a paper feed detecting member, an exposure detecting member, a paper cut detecting member and a de-energization detecting member to pivot. These pivot motions result into a paper feed linkage actuation of a paper feed device, an exposure linkage energization of an exposure lamp, and a paper cut linkage actuation of a paper cut device.
    Type: Grant
    Filed: April 11, 1979
    Date of Patent: October 20, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Koichi Sasaki, Yasuji Sumida, Hiroshi Ishida
  • Patent number: 4287282
    Abstract: Disclosed is a composite magnetic developer which consists essentially of a homogeneous intimate mixture comprising a plurality of electrically insulating magnetic particulate developers comprising a binder medium and a finely divided magnetic material dispersed in the binder medium, in which the difference of the dielectric constant between the developers is in the range of from 0.2 to 0.85.This composite magnetic developer can provide a clear transferred image having a high density on a transfer sheet such as plain paper, and even if the copying operation is conducted continuously for a long time by using this developer, excellent transferred images can be obtained without substantial change of the composition of the composite developer or substantial reduction of the image density.
    Type: Grant
    Filed: January 10, 1980
    Date of Patent: September 1, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Takashi Teshima
  • Patent number: 4286861
    Abstract: An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging mechanism and the developing mechanism, and a receptor sheet conveying system for transporting a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: September 1, 1981
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Shoji Matsumoto, Toshikazu Matsui, Toshimitsu Ikeda, Nobuhiko Kozuka, Hitoshi Nishihama, Tatsuo Aizawa
  • Patent number: 4267246
    Abstract: A developer for electrostatic images comprising a binder medium and a pigment dispersed in the binder medium is disclosed. This binder medium comprises (A) a thermoplastic or rubbery polymer containing a member selected from the group consisting of a halogen atom and a nitrile group at a concentration of at least 100 milliequivalents per 100 g of the polymer and (B) a binder having a melting temperature lower than that of the polymer (A) at an (A)/(B) mixing weight ratio of from 1/20 to 1/1. The halogen- or nitrile-containing polymer (A) is present in the form of fine particles dispersed in the continuous phase of the binder (B). This developer has good flowability and charge characteristics at the developing step and shows an excellent offset-preventing effect at the fixing step.
    Type: Grant
    Filed: February 21, 1980
    Date of Patent: May 12, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Katsumi Nishibayashi, Yoshimi Amagai, Norio Hikake, Toshihiro Kouchi, Tatsuo Aizawa
  • Patent number: 4265992
    Abstract: In a one-component type developer for electrophotography consisting essentially of a dry blend of fixing magneto-sensitive particles and flowability- and electric resistance-controlling fine particles, when an aromatic vinyl resin and/or an acrylic resin is used as a binder resin for the magneto-sensitive particles in combination with a low molecular weight olefin resin, the magneto-sensitive particles are much improved in the property of holding the flowability- and electric resistance-controlling fine particles on the surfaces thereof. Accordingly, these fine particles cannot be substantially separated from the magneto-sensitive particles under agitation conditions, development conditions and fixing conditions. As a result, contamination of the interior of a copying machine, especially an optical system, can be completely prevented, and also contamination of the background can be completely prevented.
    Type: Grant
    Filed: July 31, 1978
    Date of Patent: May 5, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Toshihiro Kouchi, Hiroshi Takayama, Tatsuo Aizawa
  • Patent number: 4264698
    Abstract: A developer for electrostatic photography consisting essentially of a dry blend of (A) substantially spherical fixing magneto-sensitive particles of a composition comprising a binder medium and a fine powder of a magnetic material dispersed in the binder medium, the substantially spherical particles (A) have on their surfaces fine convexities and concavities formed by spraying a dispersion of the composition into a drying atmosphere and have a particle size of 2 to 44 microns, and (B) flowability- and electric resistance-controlling fine particles having a volume resistivity not higher than 10.sup.12 .omega.-cm and a particle size not larger than 1/10 of the particle size of the substantially spherical particles (A). The fine particles (B) are distributed predominantly on the surface portion of said spherical particles (A). The mixing weight ratio of (A):(B) is in the range of from 1000:1 to 50:1.
    Type: Grant
    Filed: October 15, 1976
    Date of Patent: April 28, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Hiroshi Takayama, Tatsuo Aizawa
  • Patent number: 4259565
    Abstract: A method of controlling dew formation preventing heaters for a copying apparatus which includes a first temperature detecting means for detecting the temperature inside the copying apparatus, with a first reference temperature (T1) being set, a second temperature detecting means for detecting the temperature inside the copying apparatus, with a second reference temperature (T2) higher than said first reference temperature (T1) being set, a humidity detecting means for detecting the humidity inside the copying apparatus, with a reference humidity (H1) being set, and a first group of heaters and a second group of heaters to be controlled by said temperature detecting means and said humidity detecting means.
    Type: Grant
    Filed: September 5, 1979
    Date of Patent: March 31, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Tetsuo Ogino, Takashi Sengo, Toshio Yoshiyama
  • Patent number: 4259008
    Abstract: Improvements are provided in and relating to an electrostatic copying apparatus including a housing, a support for supporting an original to be copied, the support being mounted on the housing and having a transparent plate for supporting the original thereon and a holding member for covering the original on the transparent plate, a system for forming a copied image disposed within the housing and having an optical system for projecting the image of the original on the transparent plate, and a system for transferring a copying paper synchronously with the scanning of the original which is effected by the relative movement of the original holder and the optical system.
    Type: Grant
    Filed: April 10, 1979
    Date of Patent: March 31, 1981
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Ryutaro Yamagata, Sohei Matsuo, Shigeo Koyama, Nobuhiko Kozuka, Yasusuke Tohi, Tatsuo Aizawa
  • Patent number: 4254202
    Abstract: An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and a receptor sheet conveying system for transferring a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism: A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and
    Type: Grant
    Filed: April 11, 1978
    Date of Patent: March 3, 1981
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Shoji Matsumoto, Toshikazu Matsui, Toshimitsu Ikeda, Nobuhiko Kozuka, Hitoshi Nishihama, Tatsuo Aizawa
  • Patent number: 4250250
    Abstract: A photographic process comprising exposing imagewise a photosensitive layer containing a divalent tin basic salt to actinic rays to form a pattern consisting of non-reducing exposed areas and reducing non-exposed areas and contacting the exposed photo-sensitive layer with a developer capable of forming or erasing color by reduction to thereby form a visible image corresponding to said non-exposed areas or said exposed areas.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: February 10, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Hiroshi Kokado, Eiichi Inoue
  • Patent number: 4245025
    Abstract: A transfer sheet for electrostatically transferring thereon an electrically conductive or electrically semi-conductive toner in electrostatic photography or electrostatic printing, which comprises a substrate and a toner-receiving layer formed on at least one surface of the substrate, which toner-receiving layer contains a composition comprising (A) 100 parts by weight of thermoplastic acrylic-styrene copolymer and (B) 10 to 100 parts by weight of dry method finely divided silica is disclosed.In this transfer sheet, the electric resistance can be maintained at a high level even under high humidity conditions, and a toner image can be transferred on this transfer sheet at a high transfer efficiency without broadening of contours of the image. This transfer sheet has feel and touch quite similar to those of ordinary paper and is very excellent in graphic characteristics.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: January 13, 1981
    Assignee: Mita Industrial Company Limited
    Inventors: Mamoru Kato, Susumu Yamaura, Yasutoki Kamezawa, Tatsuo Aizawa
  • Patent number: 4232101
    Abstract: A photosensitive paper for electrophotography comprising a paper substrate, an electrophotographic photosensitive layer formed on one surface of the substrate and an electrically conductive coating layer formed on the other surface of the substrate, which electrically conductive coating layer comprises an electrically conductive binder medium and a fine powder of a fluorine resin distributed predominantly in the surface portion of the electrically conductive coating layer, is disclosed.This photosensitive paper is satisfactory in all of the following properties; adaptability to the paper feeding operation, the scratch resistance of the photosensitive layer, the blocking resistance and electric characteristics irrespective of the humidity conditions in the operation atmosphere.
    Type: Grant
    Filed: June 27, 1978
    Date of Patent: November 4, 1980
    Assignee: Mita Industrial Company Ltd.
    Inventors: Hideo Fukuda, Hiroichi Morikawa, Yasutoki Kamezawa, Tatsuo Aizawa
  • Patent number: 4226928
    Abstract: In a laminated photosensitive material for electrophotography, an intermediate layer comprising, incorporated in a binder, phthalocyanine or a phthalocyanine derivative and a polycyclic aromatic nitro compound at a specific ratio is formed on an electrically conductive substrate, and a top layer comprising an organic polymeric photoconductor and the above polycyclic aromatic nitro compound at a specific ratio is laminated on the intermediate layer. In this photosensitive material, the dark decay speed is controlled in a range suitable for application to the repeated copying operation and the residual potential left on the exposure area can be reduced to a negligible level. Accordingly, occurrence of fogging is prevented and the toner transfer efficiency is improved. Further, this photosensitive material has improved mechanical, chemical and electric durabilities, and therefore, the life of the photosensitive material is remarkably prolonged.
    Type: Grant
    Filed: January 5, 1978
    Date of Patent: October 7, 1980
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Toru Nakazawa, Keiichi Nagahashi, Tatsuo Aizawa
  • Patent number: 4214907
    Abstract: In a photosensitive material for electrophotography, an intermediate layer comprising an organic polymeric photoconductor and a polycyclic aromatic nitro compound at a specific ratio is formed on an electrically conductive substrate, and a top layer comprising, incorporated in a binder, phthalocyanine or phthalocyanine derivative and the above polycyclic aromatic nitro compound at a specific ratio is laminated on the intermediate layer. In this photosensitive material, the dark decay speed is controlled in a range suitable for application to the repeated copying operation and the residual potential left on the exposure area can be reduced to a negligible level. Accordingly, occurrence of fogging is prevented and the toner transfer efficiency is improved. Further, this photosensitive material has improved mechanical, chemical and electric durabilities, and therefore, the life of the photosensitive material is remarkably prolonged.
    Type: Grant
    Filed: January 5, 1978
    Date of Patent: July 29, 1980
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Toru Nakazawa, Keiichi Nagahashi, Tatsuo Aizawa
  • Patent number: 4214031
    Abstract: An electroconductive substrate for an electrically responsive recording material comprising a porous substrate and a layer of at least one cationic or anionic electric conductor, the conductor layer being formed in the porous substrate along the entire thickness direction thereof extending from one surface of the porous substrate to the other surface of the porous substrate, wherein the conductor layer has a multilayer distribution structure comprising (a) a layer of a cationic electroconductive resin distributed predominantly in the one surface portion of the porous substrate, (b) a layer of an anionic electroconductive resin distributed predominantly in the other surface portion of the porous substrate and (c) a layer of a polysalt of the cationic electroconductive resin and the anionic electroconductive resin interposed between both the electroconductive resin layers (a) and (b) in such a positional relationship that the polysalt layer (c) is adjacent to the electroconductive resin layers (a) and (b).
    Type: Grant
    Filed: April 22, 1976
    Date of Patent: July 22, 1980
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Eiichi Inoue, Hiroshi Kokado
  • Patent number: 4206088
    Abstract: A solid conducting agent comprising a finely divided inorganic solid acid and at least 0.5% by weight of a protonically conductive solid adsorbed and supported on the finely divided inorganic solid acid.This solid conducting agent is characterized by much reduced humidity dependency of the electric conductivity, and it has a sufficient electric conductivity even under low humidity conditions. An electro-responsive recording material including a layer of this solid conducting agent does not show a tacking phenomenon even under high humidity conditions.
    Type: Grant
    Filed: February 7, 1978
    Date of Patent: June 3, 1980
    Assignee: Mita Industrial Company Limited
    Inventors: Eiichi Inoue, Hiroshi Kokado, Nobuhiro Miyakawa
  • Patent number: 4199413
    Abstract: An electric recording material comprising a support and an electrically conductive recording layer formed at least in the surface portion of the substrate, which recording layer is composed of a dispersion of a basic salt of divalent tin or tin (II) hydroxide in an electrically conductive medium, gives an image having high density and contrast at relatively low electric power when applied to an electrolytic recording process utilizing cathodic reduction. This image can be preserved for a long time without discoloration of the background. Especially good results are obtained when a specific polyhydric alcohol is incorporated in the recording layer optionally with a specific organic sulfur compound.
    Type: Grant
    Filed: January 24, 1979
    Date of Patent: April 22, 1980
    Assignee: Mita Industrial Company Limited
    Inventors: Nobuhiro Miyakawa, Hiroshi Kokado, Eiichi Inoue