Patents by Inventor Yoshimi Kojima

Yoshimi Kojima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7011920
    Abstract: A non-magnetic mono-component toner of the present invention is composed of a coloring powder at least containing a binder resin, coloring agent and wax and at least one kind of external additive having a mean particle diameter of 0.04 ?m or greater, wherein the relationship between the Vickers hardness of the above coloring powder and the mean particle diameter of the external additives satisfies the predetermined expression. Thereby, the present invention is effective in preventing the external additive particles from sinking into the toner surface as well as from falling off from the surface when the toner particles are stressed in the developing unit. As a result, it is possible to provide stable image quality free from degradation of toner charge performance and toner supply performance even for long-term use.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: March 14, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takafumi Nagai, Tadayuki Sawai, Toshihisa Ishida, Kouji Kida, Kazuya Korematsu, Toru Nishikawa, Yoshimi Kojima
  • Patent number: 6780553
    Abstract: An object of the present invention is to provide an electrophotographic photoreceptor capable of recording management information for managing the electrophotographic photoreceptor in a noncontact manner, and improving management of the electrophotographic photoreceptor. An electrophotographic photoreceptor includes a conductive base, a photosensitive layer and a flange portion, wherein a noncontact information medium provided with an antenna part which communicates in a noncontact manner with a reader/writer of a main body of an electrophotographic image forming apparatus and a control part which stores management information for managing the electrophotographic photoreceptor and controls the antenna part so as to communicate with the reader/writer is disposed onto the conductive base.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: August 24, 2004
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Sugimura, Kenichi Nagata, Masanori Matsumoto, Yoshimi Kojima
  • Publication number: 20040096764
    Abstract: A non-magnetic mono-component toner of the present invention is composed of a coloring powder at least containing a binder resin, coloring agent and wax and at least one kind of external additive having a mean particle diameter of 0.04 &mgr;m or greater, wherein the relationship between the Vickers hardness of the above coloring powder and the mean particle diameter of the external additives satisfies the predetermined expression. Thereby, the present invention is effective in preventing the external additive particles from sinking into the toner surface as well as from falling off from the surface when the toner particles are stressed in the developing unit. As a result, it is possible to provide stable image quality free from degradation of toner charge performance and toner supply performance even for long-term use.
    Type: Application
    Filed: November 12, 2003
    Publication date: May 20, 2004
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Takafumi Nagai, Tadayuki Sawai, Toshihisa Ishida, Kouji Kida, Kazuya Korematsu, Toru Nishikawa, Yoshimi Kojima
  • Publication number: 20030124445
    Abstract: An object of the present invention is to provide an electrophotographic photoreceptor capable of recording management information for managing the electrophotographic photoreceptor in a noncontact manner, and improving management of the electrophotographic photoreceptor. An electrophotographic photoreceptor includes a conductive base, a photosensitive layer and a flange portion, wherein a noncontact information medium provided with an antenna part which communicates in a noncontact manner with a reader/writer of a main body of an electrophotographic image forming apparatus and a control part which stores management information for managing the electrophotographic photoreceptor and controls the antenna part so as to communicate with the reader/writer is disposed onto the conductive base.
    Type: Application
    Filed: December 26, 2002
    Publication date: July 3, 2003
    Inventors: Hiroshi Sugimura, Kenichi Nagata, Masanori Matsumoto, Yoshimi Kojima
  • Patent number: 5492786
    Abstract: The present invention is directed to an electrophotographic photoreceptor which is smooth without orange peel, inhibits the rise of a residual potential and the drop of a charged potential, and is excellent in stability even when it is repeatedly used.The photoreceptor comprises a charge generation material, a charge transport material, a polyarylate having a polymerization degree of 10 to 5,000, a polycarbonate having a polymerization degree of 10 to 5,000, and a polydimethylsiloxane having a polymerization degree of 0 to 2,000.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: February 20, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Sugimura, Satoshi Katayama, Kazushige Morita, Yoshimi Kojima, Yoshimasa Fujita, Satoshi Nishigaki, Kazuhiro Emoto
  • Patent number: 5489496
    Abstract: An electrophotographic photoconductor comprising a conductive support, an undercoating layer provided on the conductive support and a photosensitive layer provided on the undercoating layer, in which the undercoating layer comprises a needle-like titanium oxide particles and a binder resin. The needle-like titanium oxide particles in the undercoating layer show a volume resistance in the range from 10.sup.5 .OMEGA..multidot.cm to 10.sup.10 .OMEGA..multidot.cm when a loading pressure of 100 Kg/cm.sup.2 is applied and have a short axis S having a length of 0.5 .mu.m or less and a long axis L having a length of 10 .mu.m or less and the aspect ratio of L/S ranging from 2 to 10. Further, the needle-like titanium oxide particles are contained in the undercoating layer in the range from 50 wt % to 95 wt % and the surface thereof remains untreated.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: February 6, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoshi Katayama, Satoshi Nishigaki, Kazuhiro Emoto, Hiroshi Sugimura, Kazushige Morita, Yoshimi Kojima, Yoshimasa Fujita
  • Patent number: 5396354
    Abstract: In the liquid crystal display, a liquid crystal layer is provided between a first insulating substrate and a second insulating substrate. A plurality of first electrodes are arranged in parallel on the first insulating substrate in a first direction, and a first insulating layer is formed on the entire surface of the first insulating substrate and covers the first electrodes. A semiconductor layer is formed on the first insulating layer, and a second insulating layer is formed thereon and covers the entire surface of the first insulating substrate. This triple-layered structure constitutes a switching element array. A plurality of second electrodes are arranged in parallel on the second insulating electrode in a second direction crossing the first direction. Thus, the switching element array sandwiched between the first and second electrodes is used for driving the liquid crystal layer.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: March 7, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasunori Shimada, Tomohiko Yamamoto, Hiroshi Morimoto, Yoshimi Kojima, Mitsuhiro Koden, Masaru Yoshida
  • Patent number: 5116706
    Abstract: 1,2,4,5-Benzoylenebis(naphto[1,8-de]pyrimidine) compounds of the followig formula (I) or (II): ##STR1## wherein R and R' are, the same or different, hydrogen atom, a halogen atom, hydroxyl group, nitro group, cyano group, an alkyl group which may be substituted, an alkoxyl group which may be substituted, an aryl group which may be substituted, an aralkyl group which may be substituted, a carboxyl group which may be esterified or a carbamoyl group which may be substituted and m and n each are an integer from 1 to 6, and photosensitive members for electrophotography having a photosensitive layer containing them.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: May 26, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshimi Kojima, Satoshi Katayama, Yoshihide Shimoda, Hiroshi Sugimura, Eiji Imada
  • Patent number: 4943503
    Abstract: An amorphous silicon (a-Si) photoreceptor includes an amorphous silicon (a-Si) photoconductive layer, and a surface layer disposed above the amorphous silicon (a-Si) photoconductive layer. An intermediate layer is disposed between the amorphous-silicon (a-Si) photoconductive layer and the surface layer to ensure the energy level matching. The intermediate layer is made of amorphous silicon (a-Si) doped with nitrogen and boron so as to have the energy difference of less than 0.2 eV between the bottom of the conduction bands of the surface layer and the intermediate layer.
    Type: Grant
    Filed: October 10, 1984
    Date of Patent: July 24, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hideo Nojima, Yoshimi Kojima, Eiji Imada, Toshiro Matsuyama, Takashi Hayakawa, Shiro Narikawa, Shaw Ehara
  • Patent number: 4883733
    Abstract: An electrophotographic printing process is disclosed that comprises the steps of: imagewise exposing a photosensitive means with light of a wavelength at which photochromism occurs, to thereby record the image therein, wherein said photosensitive means has a photosensitive layer formed on a conductive support, said photosensitive layer containing a photochromically sensitive compound that shows photoconductivity when irradiated with light of different wavelengths before and after said photochromism occurs; charging the entire surface of said photosensitive layer; and uniformly exposing said photosensitive means with light of a wavelength at which photochromism does not occur, but at which said photochromically sensitive compound or photoisomeric compound therewith shows photoconductivity, to thereby form the image of a charge pattern on the surface of said photosensitive layer.
    Type: Grant
    Filed: July 15, 1988
    Date of Patent: November 28, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Sugimura, Eiji Imada, Yoshimi Kojima, Shuhei Tsuchimoto
  • Patent number: 4853309
    Abstract: A photoreceptor for electrophotography including an electrically conductive substrate, a bottom layer, a photoconductive layer composed mainly of amorphous silicon, and a surface layer, in that order. Both the bottom and surface layers have a greater optical bandgap than said photoconductive layer. A first middle layer is disposed between said bottom layer and said photoconductive layer, and a second middle layer is disposed between said photoconductive layer and said surface layer. Both the first and second middle layers are composed mainly of amorphous silicon and have a concentration of doped atoms which varies from the bottom to the top of the layer.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: August 1, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Hayakawa, Hideo Nojima, Yoshimi Kojima, Shiro Narikawa, Toshiro Matsuyama, Eiji Imada, Shaw Ehara
  • Patent number: 4851256
    Abstract: An apparatus for manufacturing photosensitive amorphous silicon objects comprises a pair of coaxial cylindrical electrodes inside a reaction tank of a plasma CVD device. A plurality of cylindrical substrates of an electrically conductive material disposed between these electrodes. A source gas is injected into the reaction tank through a plurality of inlets evenly spaced on the outer peripheral wall so that films of uniform quality can be produced efficiently.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: July 25, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiro Matsuyama, Yoshimi Kojima, Shaw Ehara
  • Patent number: 4687724
    Abstract: A photoreceptor for electrophotography utilizing a-Si:N:H:F, wherein a stable high-sensitive layer is provided and the time-lapse variation in characteristics is reduced in the use of an a-Si.sub.1-x N.sub.x layer as a sensitive layer.
    Type: Grant
    Filed: December 14, 1983
    Date of Patent: August 18, 1987
    Assignee: Sharp Kabushiki
    Inventors: Shaw Ehara, Yoshimi Kojima, Eiji Imada, Takashi Hayakawa, Toshiro Matsuyama
  • Patent number: 4666816
    Abstract: A method of manufacturing an electrophotographic photoreceptor having an amorphous silicon layer formed as a photoconductive layer, on an electrically conductive support member. The manufacturing method includes the steps of preparing the amorphous silicon layer as the photoconductive layer by employing Si.sub.2 H.sub.6 (disilane) as a main raw material gas through a glow discharge process, and simultaneously, adding nitrogen and boron to the main raw material gas, with the unsaturated bond being stabilized by hydrogen or hydrogen and fluorine.
    Type: Grant
    Filed: August 26, 1986
    Date of Patent: May 19, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshimi Kojima, Shiro Narikawa, Takashi Hayakawa, Hideo Nojima, Eiji Imada, Toshiro Matsuyama, Shaw Ehara
  • Patent number: 4615299
    Abstract: A plasma CVD (chemical vapor deposition) apparatus of the capacitance coupling type for effecting the chemical vapor deposition on a drum which includes an air tight chamber made of an electrically conductive material, a support provided in the chamber for supporting the drum inside the chamber in an electrically insulated relationship with the chamber, and an RF power source for supplying RF power to the drum. The chamber is grounded and, therefore, the plasma is generated between the drum and inside wall of the chamber. The apparatus is provided with means for providing a smooth surface on the drum. The drum can be used as a photoreceptor for use in an electrophotographic copying machine.
    Type: Grant
    Filed: March 7, 1985
    Date of Patent: October 7, 1986
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiro Matsuyama, Takashi Hayakawa, Yoshimi Kojima, Shiro Narikawa, Shaw Ehara