Patents by Inventor Tatsuya Niimi

Tatsuya Niimi 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: 7029810
    Abstract: An electrophotographic image forming apparatus comprising: an electrophotographic photoreceptor comprising: an electroconductive substrate; a charge generation layer; and a charge transport layer in this order, a charger; an irradiator; an image developer; and a transferer applying an electric current not less than 65 ?A to the electrophotographic photoreceptor, wherein the charge generation layer comprises titanylphthalocyanine crystals having a CuK? 1.542 ? X-ray diffraction spectrum having plural diffraction peaks, wherein a maximum diffraction peak is observed at a Bragg (2 ?) angle of 27.2°; main peaks are observed at 9.4°, 9.6° and 24.0°; and a minimum diffraction peak is observed at 7.3°; and no diffraction peak is observed at an angle greater than 7.3° and less than 9.4°, wherein said angles may vary by ±0.2° and the minimum interval where no peak is observed between required peaks at 7.3 and 9.4 is 2.0 degrees absolute or more.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: April 18, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Naohiro Toda, Tatsuya Niimi
  • Publication number: 20060057479
    Abstract: A coating liquid for an intermediate layer of an electrophotographic photoconductor comprises at least one of alcohol solvents; and N-methoxymethylated nylon, in which the N-methoxymethylated nylon has solution viscosity within a range from 43 mPa·s to 50 mPa·s when dissolving into methanol at 30° C. in a concentration of 20% by mass.
    Type: Application
    Filed: September 7, 2005
    Publication date: March 16, 2006
    Inventors: Tatsuya Niimi, Maiko Kondo, Nozomu Tamoto, Katsuichi Ohta
  • Publication number: 20060008719
    Abstract: A photoreceptor including at least an electroconductive substrate, and a charge blocking layer, a moiré preventing layer, and a photosensitive layer, which are located overlying the electroconductive substrate in this order, wherein the photosensitive layer includes an azo pigment having a fluorenone skeleton. The photosensitive layer is preferably prepared by coating a coating liquid including a dispersion which is prepared by dispersing the azo pigment in a solvent to an extent such that the average particle diameter of the azo pigment is not greater than 0.3 ?m and the standard deviation of the particle diameter is not greater than 0.2 ?m, followed by filtering with a filter having an effective pore diameter not greater than 5 ?m. An image forming apparatus and a process cartridge including the photoreceptor.
    Type: Application
    Filed: June 27, 2005
    Publication date: January 12, 2006
    Inventor: Tatsuya Niimi
  • Publication number: 20050175911
    Abstract: The object of the present invention is to provide a photoconductor that is highly sensitive, stable in image quality under repeated usages, and affords prolonged life. In order attain the object, a photoconductor is provided that comprises a charge generating layer, a charge transporting layer, and a crosslinked charge transporting layer, on an substrate in order, the charge generating layer contains titanyl phthalocyanine crystal particles that exhibit a highest peak at 27.2°, main peaks at 9.4°, 9.6° and 24.0°, a peak at 7.3° as the lowest angle, and with no peaks in a range between 7.3° and 9.4°, and with no peak at 26.3° as Bragg 2?angles (±0.2°) in terms of CuK-? characteristic X-ray wavelength at 1.542 ?, and the averaged primary particle size of the titanyl phthalocyanine crystal particles is 0.
    Type: Application
    Filed: October 28, 2004
    Publication date: August 11, 2005
    Inventors: Nozomu Tamoto, Tatsuya Niimi, Tetsuro Suzuki, Katsuichi Ohta
  • Patent number: 6902857
    Abstract: A method for forming an electrophotographic image and a device for forming an image on a transfer material by the steps for charging, exposing, developing and transferring, and recovering the toner remained untransferred in the step for cleaning by recovering, wherein the toner used in the step for developing has a total surface area ratio Z of additive, which is calculated by Z=(Ht·Wt)/(H·W), satisfies 0.5?Z?1.5, the electrophotographic photoconductor used comprises at least a photosensitive layer and a filler-containing protective layer provided on a conductive support in that order, and the angle of repose of the toner to the protective layer surface of the electrophotographic photoconductor is 30° or less.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: June 7, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichiro Yagi, Naohito Shimota, Tatsuya Niimi, Satoshi Mochizuki, Hiroaki Matsuda, Tomomi Tamura
  • Patent number: 6902858
    Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 ?m.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: June 7, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Mochizuki, Naohito Shimota, Hiroaki Matsuda, Shinichiro Yagi, Tomomi Tamura, Tatsuya Niimi
  • Publication number: 20050106482
    Abstract: A photoreceptor including an electroconductive substrate; and a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler, wherein the content of the inorganic filler at a surface side of the photosensitive layer is greater than that at a bottom side of the photosensitive layer near the electroconductive substrate, and wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m?2·24 h?1.
    Type: Application
    Filed: December 22, 2004
    Publication date: May 19, 2005
    Inventors: Hidetoshi Kami, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Nozomu Tamoto
  • Publication number: 20050100804
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and optionally a protective layer overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, a binder resin and an organic compound having an acid value of from 10 to 700 mgKOH/g. The photosensitive layer can be the outermost layer. A coating liquid for an outermost layer of a photoreceptor including a filler, a binder resin, an organic compound having an acid value of from 10 to 700 mgKOH/g and plural organic solvents. A method for preparing a photoreceptor including forming a photosensitive layer, and coating the coating liquid on the photosensitive layer. An image forming method and apparatus and a process cartridge using the photoreceptor are also provided.
    Type: Application
    Filed: July 24, 2003
    Publication date: May 12, 2005
    Inventors: Nozomu Tamoto, Tetsuro Suzuki, Hiroshi Tamura, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Hidetoshi Kami
  • Publication number: 20050084287
    Abstract: The present invention relates to an image forming apparatus, an image forming process and a process cartridge, in which the image quality and the durability of the photoconductor may be enhanced, images may be formed stably even after the repeated usages, and higher quality and higher stability of images may be established due to the superimposed alternating voltage as well as decrease of the charging hazard on the photoconductor. Specifically, the image forming apparatus according to the present invention comprises a photoconductor, latent electrostatic image forming unit, developing unit a transferring unit, and fixing unit, wherein, the charging member is of roller shape disposed proximate to the photoconductor, the photoconductor is charged at the charging nip portion formed between the photoconductor and the charging member, in a condition that satisfies the following Equation: 4.4×1014?[(Number of Charged Particles)÷(Perimeter of Photoconductor)]?17.
    Type: Application
    Filed: August 27, 2004
    Publication date: April 21, 2005
    Inventors: Tatsuya Niimi, Masami Kadonaga
  • Publication number: 20050069797
    Abstract: A photoreceptor including an electroconductive substrate; and a charge blocking layer; a moiré preventing layer; and a photosensitive layer, which are overlaid overlying the substrate in this order, wherein the photosensitive layer includes a titanyl phthalocyanine crystal which has an average primary particle diameter not greater than 0.25 ?m, and has an X-ray diffraction spectrum such that a maximum peak is observed at a Bragg (2?) angle of 27.2°±0.2°; a peak is observed at Bragg (2?) angle of 9.4°±0.2°, 9.6±0.2° and 24.0±0.2°; a lowest angle peak is observed at an angle of 7.3°±0.2°; no peak is observed between the lowest angle peak and the 9.4° peak; and no peak is observed at a Bragg (2?) angle of 26.3°±0.2°, when a Cu—K? X-ray having a wavelength of 0.1542 nm (1.542 ?) is used.
    Type: Application
    Filed: September 20, 2004
    Publication date: March 31, 2005
    Inventors: Tatsuya Niimi, Nozomu Tamoto, Katsuichi Ohta
  • Patent number: 6858362
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and optionally a protective layer overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, a binder resin and an organic compound having an acid value of from 10 to 700 mgKOH/g. The photosensitive layer can be the outermost layer. A coating liquid for an outermost layer of a photoreceptor including a filler, a binder resin, an organic compound having an acid value of from 10 to 700 mgKOH/g and plural organic solvents. A method for preparing a photoreceptor including forming a photosensitive layer, and coating the coating liquid on the photosensitive layer. An image forming method and apparatus and a process cartridge using the photoreceptor are also provided.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: February 22, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Nozomu Tamoto, Tetsuro Suzuki, Hiroshi Tamura, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Hidetoshi Kami
  • Patent number: 6844124
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate and including a resin; and a surface layer including a filler and a binder resin, wherein the surface layer and the photosensitive layer have a continuous structure, and wherein the surface layer satisfies the following relationship: ??D/5, wherein D represents an average of maximum thicknesses of the surface layer in units of micrometers in 20 segments of 5 ?m wide when a portion of a cross section of the photoreceptor of 100 ?m wide is divided into the 20 segments, and ? represents a standard deviation of the 20 maximum thicknesses.
    Type: Grant
    Filed: August 12, 2003
    Date of Patent: January 18, 2005
    Assignee: Ricoh Company Limited
    Inventors: Hiroshi Ikuno, Hidetoshi Kami, Ryohichi Kitajima, Narihito Kojima, Akihiko Matsuyama, Hiroshi Nagame, Katsuichi Ohta, Tetsuro Suzuki, Nozomu Tamoto, Hiroshi Tamura, Yohta Sakon, Eiji Kurimoto, Tatsuya Niimi, Yuka Miyamoto
  • Publication number: 20040234875
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, a charge generation layer, and a charge transport layer formed by using a halogen-free solvent, arranged in this order, in which the charge generation layer contains a charge generation material having an average particle diameter smaller than a surface roughness of a plane where the electroconductive substrate is arranged, and a polyvinyl acetal resin having a ratio Mw/Mn of a weight-average molecular weight Mw to a number-average molecular weight Mn is 2.2 or more.
    Type: Application
    Filed: March 19, 2004
    Publication date: November 25, 2004
    Inventors: Naohiro Toda, Tatsuya Niimi, Ryohichi Kitajima, Yoshiaki Kawasaki
  • Patent number: 6803162
    Abstract: An image forming apparatus including a photoreceptor, wherein the photoreceptor includes an image forming portion having two ends substantially parallel to the rotating direction and a gap forming member located outside of each of the two ends of the image forming portion; a charging roller configured to charge the photoreceptor, wherein the charging roller contacts the gap forming members of the photoreceptor to form a gap g between the surface of the image forming portion and the peripheral surface thereof; an imagewise light irradiator; an image developer; and an image transfer device, wherein the relationship t≧2g is satisfied, where g represents the gap and t represents a distance between an inside edge of one of the gap forming members and nearer one of the two ends of the image forming portion of the photoreceptor.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: October 12, 2004
    Assignee: Ricoh Company, Ltd.
    Inventor: Tatsuya Niimi
  • Publication number: 20040197688
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and optionally a protective layer overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, a binder resin and an organic compound having an acid value of from 10 to 700 mgKOH/g. The photosensitive layer can be the outermost layer. A coating liquid for an outermost layer of a photoreceptor including a filler, a binder resin, an organic compound having an acid value of from 10 to 700 mgKOH/g and plural organic solvents. A method for preparing a photoreceptor including forming a photosensitive layer, and coating the coating liquid on the photosensitive layer. An image forming method and apparatus and a process cartridge using the photoreceptor are also provided.
    Type: Application
    Filed: April 20, 2004
    Publication date: October 7, 2004
    Inventors: Nozomu Tamoto, Tetsuro Suzuki, Hiroshi Tamura, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Hidetoshi Kami
  • Publication number: 20040179861
    Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 &mgr;m.
    Type: Application
    Filed: March 19, 2004
    Publication date: September 16, 2004
    Inventors: Satoshi Mochizuki, Naohito Shimota, Hiroaki Matsuda, Shinichiro Yagi, Tomomi Tamura, Tatsuya Niimi
  • Patent number: 6790572
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and optionally a protective layer overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, a binder resin and an organic compound having an acid value of from 10 to 700 mgKOH/g. The photosensitive layer can be the outermost layer. A coating liquid for an outermost layer of a photoreceptor including a filler, a binder resin, an organic compound having an acid value of from 10 to 700 mgKOH/g and plural organic solvents. A method for preparing a photoreceptor including forming a photosensitive layer, and coating the coating liquid on the photosensitive layer. An image forming method and apparatus and a process cartridge using the photoreceptor are also provided.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: September 14, 2004
    Assignee: Ricoh Company Limited
    Inventors: Nozomu Tamoto, Tetsuro Suzuki, Hiroshi Tamura, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Hidetoshi Kami
  • Publication number: 20040126686
    Abstract: An electrophotographic image forming apparatus comprising:
    Type: Application
    Filed: September 22, 2003
    Publication date: July 1, 2004
    Inventors: Naohiro Toda, Tatsuya Niimi
  • Publication number: 20040126689
    Abstract: An electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and optionally a protective layer overlying the photosensitive layer, wherein an outermost layer of the photoreceptor includes a filler, a binder resin and an organic compound having an acid value of from 10 to 700 mgKOH/g. The photosensitive layer can be the outermost layer. A coating liquid for an outermost layer of a photoreceptor including a filler, a binder resin, an organic compound having an acid value of from 10 to 700 mgKOH/g and plural organic solvents. A method for preparing a photoreceptor including forming a photosensitive layer, and coating the coating liquid on the photosensitive layer. An image forming method and apparatus and a process cartridge using the photoreceptor are also provided.
    Type: Application
    Filed: July 23, 2003
    Publication date: July 1, 2004
    Inventors: Nozomu Tamoto, Tetsuro Suzuki, Hiroshi Tamura, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Hidetoshi Kami
  • Patent number: 6757507
    Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 &mgr;m.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: June 29, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Mochizuki, Naohito Shimota, Hiroaki Matsuda, Shinichiro Yagi, Tomomi Tamura, Tatsuya Niimi