Patents by Inventor Akihiko Gotoh

Akihiko Gotoh 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: 6899751
    Abstract: An ink for ink jet recording which is used for an ink jet printer in which at least a portion of a member being in contact with the ink is formed by any one of a borosilicate glass, a soda lime glass, a photosensitive glass, single crystal silicon, polysilicon, a silicon oxide film, a titanium nitride film, a zirconium film, a titanium oxide film, and a silicon nitride film, wherein a corrosion inhibitor is contained, and a phosphonium ion represented by the general formula (Formula 1) described below is contained: (wherein in Formula 1, Ra, Rb, Rc and Rd represent a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a halogenated alkyl group and a substituted or non substituted phenyl group, and X? represents a counter ion) is provided.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: May 31, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Arita, Nobutaka Osada, Kiyofumi Nagai, Kakuji Murakami, Akihiko Gotoh
  • Publication number: 20050054751
    Abstract: An ink and ink set characterized in that both a combination of a specific wetting agent, penetrating agent, and water-soluble organic solvent and use of surfactant, particularly fluorine surfactant are enabled by using water dispersion in which polymer fine particles contain coloring material. Even when plain paper is printed at high speed by ink-jet recording by using this ink and ink set, the ink and ink set can realize a pigment ink for ink-jet recording, an ink set, an ink-jet recording method, ink cartridge, and recorder which have an excellent ejection stability and excellent preservability, and provide (1) good color tone, (2) high image density, (3) recorded image free of unsharpness near character or image and feathering and high in sharpness, (4) less boundary color bleedings between different colors, (5) image adaptable to both-side printing and causing less strike-throughs, and (6) image fastness such as water resistance and light resistance.
    Type: Application
    Filed: August 5, 2004
    Publication date: March 10, 2005
    Inventors: Michihiko Namba, Toshiroh Tokuno, Akihiko Gotoh, Kiyofumi Nagai
  • Publication number: 20050007431
    Abstract: An image recording method including: applying a pretreatment liquid on a surface of a recording material; and discharging a recording ink according to image signals to form an ink image on the pretreatment liquid on the surface of the recording material before the pretreatment liquid applied to the recording material has dried, wherein the recording ink includes a solvent and a component dispersed or dissolved in the solvent, wherein the pretreatment liquid includes a compound depressing at least one of the dispersibility and solubility of the component in the recording ink in an amount of 10 to 80% by weight based on total weight, and wherein the pretreatment liquid has a viscosity of from 10 to 10,000 mPa·s at 25° C.
    Type: Application
    Filed: July 13, 2004
    Publication date: January 13, 2005
    Inventors: Masayuki Koyano, Hitoshi Arita, Tetsuya Kaneko, Nobutaka Osada, Kakuji Murakami, Akihiko Gotoh, Akiko Bannai, Tomoko Maeda, Kiyofumi Nagai
  • Publication number: 20040179066
    Abstract: An ink composition including a colorant; and a solvent, wherein a zeta potential 2 between the colorant and a material selected from the group consisting of silicon, glass, silicon oxide, titanium oxide, chromium oxide, titanium nitride, silicon nitride, zirconium and polyimide is from 0 to −50 mV at a pH of from 6.5 to 11.5. A corrosion inhibitor is preferably added to the ink composition to adjust the zeta potential 2. An ink cartridge containing the ink which optionally includes a recording head discharging the ink to form an image on a recording material, wherein the zeta potential 2 between the colorant in the ink and a material of the recording head contacting the ink is from 0 to −50 mV at a pH of from 6.5 to 11.5. An inkjet recording apparatus including the ink cartridge and a carriage carrying the ink cartridge.
    Type: Application
    Filed: March 11, 2004
    Publication date: September 16, 2004
    Applicant: Ricoh Company Limited
    Inventors: Hitoshi Arita, Nobutaka Osada, Kiyofumi Nagai, Kakuji Murakami, Tomoko Maeda, Akihiko Gotoh
  • Patent number: 6786588
    Abstract: An image recording method including: applying a pretreatment liquid on a surface of a recording material; and discharging a recording ink according to image signals to form an ink image on the pretreatment liquid on the surface of the recording material before the pretreatment liquid applied to the recording material has dried, wherein the recording ink includes a solvent and a component dispersed or dissolved in the solvent, wherein the pretreatment liquid includes a compound depressing at least one of the dispersibility and solubility of the component in the recording ink in an amount of 100 to 80% by weight based on total weight, and wherein the pretreatment liquid has a viscosity of from 10 to 10,000 mPa·s at 25° C.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: September 7, 2004
    Assignee: Ricoh Company Limited
    Inventors: Masayuki Koyano, Hitoshi Arita, Tetsuya Kaneko, Nobutaka Osada, Kakuji Murakami, Akihiko Gotoh, Akiko Bannai, Tomoko Maeda, Kiyofumi Nagai
  • Patent number: 6730155
    Abstract: An aqueous ink composition contains at least one pigment selected from the group consisting of a condensed azo pigment, a condensed polycyclic pigment, a phthalocyanine pigment, and a nickel complex azo pigment, at least an anionic surfactant with ethylene oxide group or a nonionic surfactant with ethylene oxide group as a dispersant, a wetting agent, a penetrating agent, and water, with the ink composition having a surface tension of 20 mN/m or more and less than 35 mN/m. A yellow ink containing at least one pigment selected from the group consisting of C.I. Pigment Yellow 128, C.I. Pigment Yellow 138, C.I. Pigment Yellow 151, C.I. Pigment Yellow 97, and C.I. Pigment Yellow 150, a magenta ink containing at least one pigment of C.I. Pigment Red 122 or C.I. Pigment Violet 19, a cyan ink containing at least one pigment of C.I. Pigment Blue 15:3 or C.I. Pigment Blue 15:4, each color ink further containing a specific anionic surfactant and a water-soluble organic solvent, and a black ink containing C.I.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: May 4, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Gotoh, Tomoko Maeda, Akiko Bannai, Kiyofumi Nagai, Hitoshi Arita, Tetsuya Kaneko, Nobutaka Osada, Toshiroh Tokuno, Masayuki Koyano, Kakuji Murakami
  • Patent number: 6730149
    Abstract: An ink composition including a colorant; and a solvent, wherein a zeta potential 2 between the colorant and a material selected from the group consisting of silicon, glass, silicon oxide, titanium oxide, chromium oxide, titanium nitride, silicon nitride, zirconium and polyimide is from 0 to −50 mV at a pH of from 6.5 to 11.5. A corrosion inhibitor is preferably added to the ink composition to adjust the zeta potential 2. An ink cartridge containing the ink which optionally includes a recording head discharging the ink to form an image on a recording material, wherein the zeta potential 2 between the colorant in the ink and a material of the recording head contacting the ink is from 0 to −50 mV at a pH of from 6.5 to 11.5. An inkjet recording apparatus including the ink cartridge and a carriage carrying the ink cartridge.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: May 4, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hitoshi Arita, Nobutaka Osada, Kiyofumi Nagai, Kakuji Murakami, Tomoko Maeda, Akihiko Gotoh
  • Patent number: 6695443
    Abstract: An ink for ink jet recording and an ink jet recording method which realize an image quality of laser printer on a plain paper in a one-pass printing mode under conditions of a volume of an ink droplet ejected being 5 to 43 Pico liter, a velocity of an ink droplet being 6 to 20 m/sec, frequency of 1 kHz and resolution of 300 dpi or more. The ink for ink jet recording is a penetrating type ink which includes (1) at least one humectant selected from glycerin, 1,3-butandiol, triethyleneglycol, 1,6-hexanediol, propyleneglycol, 1,5-pentanediol, diethyleneglycol, dipropyleneglycol, trimethylolpropane and trimethylolethane, (2) colorant contained in the amount of 6% by weight or more, (3) a polyol having 8 to 11 carbon atoms and glycolether, and an anionic surfactants or non-ionic surfactants, the ink has viscosity of 5 mPa·s or more at 25° C. and a surface tension of 40 mN/m or less.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: February 24, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Arita, Kiyofumi Nagai, Akihiko Gotoh, Akiko Bannai, Tetsuya Kaneko, Nobutaka Osada, Tomoko Maeda, Masayuki Koyano, Kakuji Murakami, Toshiroh Tokuno
  • Patent number: 6578958
    Abstract: An inkjet recording apparatus including (A) a recording head including: plural nozzles discharging an ink drop to form an image on a receiving material; and plural pressure generators applying a pressure to the corresponding nozzles; (B) an ink container containing the ink, wherein the ink includes a pigment and a volatile solvent, and wherein the ink has a pigment content decreasing property such that the pigment content decreases at a meniscus portion of the ink in the nozzles when the ink is allowed to settle; and (C) a driver selectively actuating the pressure generators to discharge the ink from the corresponding nozzles, wherein the driver selectively actuates at least one of the pressure generators at a predetermined timing such that the ink at the meniscus portion is vibrated to an extent such that the ink is not discharged from the corresponding nozzle.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: June 17, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Gotoh, Akiko Bannai
  • Publication number: 20030107632
    Abstract: An ink for ink jet recording and an ink jet recording method which realize an image quality of laser printer on a plain paper in a one-pass printing mode under conditions of a volume of an ink droplet ejected being 5 to 43 Pico liter, a velocity of an ink droplet being 6 to 20 m/sec, frequency of 1 kHz and resolution of 300 dpi or more. The ink for ink jet recording is a penetrating type ink which comprises (1) at least one humectant selected from glycerin, 1,3-butandiol, triethyleneglycol, 1,6-hexanediol, propyleneglycol, 1,5-pentanediol, diethyleneglycol, dipropyleneglycol, trimethylolpropane and trimethylolethane, (2) colorant contained in the amount of 6 % by weight or more, (3) a polyol having 8 to 11 carbon atoms and glycolether, and an anionic surfactants or non-ionic surfactants, the ink has viscosity of 5 mPa.s or more at 25° C. and a surface tension of 40 mN/m or less.
    Type: Application
    Filed: May 29, 2002
    Publication date: June 12, 2003
    Inventors: Hitoshi Arita, Kiyofumi Nagai, Akihiko Gotoh, Akiko Bannai, Tetsuya Kaneko, Nobutaka Osada, Tomoko Maeda, Masayuki Koyano, Kakuji Murakami, Toshiroh Tokuno
  • Publication number: 20030076394
    Abstract: An inkjet recording apparatus including (A) a recording head including: plural nozzles discharging an ink drop to form an image on a receiving material; and plural pressure generators applying a pressure to the corresponding nozzles; (B) an ink container containing the ink, wherein the ink includes a pigment and a volatile solvent, and wherein the ink has a pigment content decreasing property such that the pigment content decreases at a meniscus portion of the ink in the nozzles when the ink is allowed to settle; and (C) a driver selectively actuating the pressure generators to discharge the ink from the corresponding nozzles, wherein the driver selectively actuates at least one of the pressure generators at a predetermined timing such that the ink at the meniscus portion is vibrated to an extent such that the ink is not discharged from the corresponding nozzle.
    Type: Application
    Filed: March 22, 2002
    Publication date: April 24, 2003
    Inventors: Akihiko Gotoh, Akiko Bannai
  • Publication number: 20030064206
    Abstract: An image recording method including: applying a pretreatment liquid on a surface of a recording material; and discharging a recording ink according to image signals to form an ink image on the pretreatment liquid on the surface of the recording material before the pretreatment liquid applied to the recording material has dried, wherein the recording ink includes a solvent and a component dispersed or dissolved in the solvent, wherein the pretreatment liquid includes a compound depressing at least one of the dispersibility and solubility of the component in the recording ink in an amount of 10 to 80 % by weight based on total weight, and wherein the pretreatment liquid has a viscosity of from 10 to 10,000 mPa·s at 25 ° C.
    Type: Application
    Filed: March 18, 2002
    Publication date: April 3, 2003
    Inventors: Masayuki Koyano, Hitoshi Arita, Tetsuya Kaneko, Nobutaka Osada, Kakuji Murakami, Akihiko Gotoh, Akiko Bannai, Tomoko Maeda, Kiyofumi Nagai
  • Publication number: 20030010252
    Abstract: An ink composition including a colorant; and a solvent, wherein a zeta potential 2 between the colorant and a material selected from the group consisting of silicon, glass, silicon oxide, titanium oxide, chromium oxide, titanium nitride, silicon nitride, zirconium and polyimide is from 0 to −50 mV at a pH of from 6.5 to 11.5. A corrosion inhibitor is preferably added to the ink composition to adjust the zeta potential 2. An ink cartridge containing the ink which optionally includes a recording head discharging the ink to form an image on a recording material, wherein the zeta potential 2 between the colorant in the ink and a material of the recording head contacting the ink is from 0 to −50 mV at a pH of from 6.5 to 11.5. An inkjet recording apparatus including the ink cartridge and a carriage carrying the ink cartridge.
    Type: Application
    Filed: January 22, 2002
    Publication date: January 16, 2003
    Inventors: Hitoshi Arita, Nobutaka Osada, Kiyofumi Nagai, Kakuji Murakami, Tomoko Maeda, Akihiko Gotoh
  • Publication number: 20020096085
    Abstract: An aqueous ink composition contains at least one pigment selected from the group consisting of a condensed azo pigment, a condensed polycyclic pigment, a phthalocyanine pigment, and a nickel complex azo pigment, at least an anionic surfactant with ethylene oxide group or a nonionic surfactant with ethylene oxide group as a dispersant, a wetting agent, a penetrating agent, and water, with the ink composition having a surface tension of 20 mN/m or more and less than 35 mN/m. A yellow ink containing at least one pigment selected from the group consisting of C.I. Pigment Yellow 128, C.I. Pigment Yellow 138, C.I. Pigment Yellow 151, C.I. Pigment Yellow 97, and C.I. Pigment Yellow 150, a magenta ink containing at least one pigment of C.I. Pigment Red 122 or C.I. Pigment Violet 19, a cyan ink containing at least one pigment of C.I. Pigment Blue 15:3 or C.I. Pigment Blue 15:4, each color ink further containing a specific anionic surfactant and a water-soluble organic solvent, and a black ink containing C.I.
    Type: Application
    Filed: June 29, 2001
    Publication date: July 25, 2002
    Applicant: Ricoh Company, Ltd.
    Inventors: Akihiko Gotoh, Tomoko Maeda, Akiko Bannai, Kiyofumi Nagai, Hitoshi Arita, Tetsuya Kaneko, Nobutaka Osada, Toshiroh Tokuno, Masayuki Koyano, Kakuji Murakami
  • Publication number: 20020083866
    Abstract: An ink for ink jet recording which is used for an ink jet printer in which at least a portion of a member being in contact with the ink is formed by any one of a borosilicate glass, a soda lime glass, a photosensitive glass, single crystal silicon, polysilicon, a silicon oxide film, a titanium nitride film, a zirconium film, a titanium oxide film, and a silicon nitride film, wherein a corrosion inhibitor is contained, and a phosphonium ion represented by the general formula (Formula 1) described below is contained: 1
    Type: Application
    Filed: October 1, 2001
    Publication date: July 4, 2002
    Inventors: Hitoshi Arita, Nobutaka Osada, Kiyofumi Nagai, Kakuji Murakami, Akihiko Gotoh
  • Patent number: 6020103
    Abstract: A liquid toner for use in a liquid developer contains a dispersion medium and toner particles, each of which toner particles contains a coloring agent and a binder agent and is dispersed in the dispersion medium, the toner particles comprising small toner particles with a particle diameter of 0.1 .mu.m or less in an amount of 20 wt. % or less of the total weight of the toner particles, and having an average particle diameter of 0.3 to 5 .mu.m. Using the above-mentioned liquid toner in which the amount of the toner particles is controlled to 5 to 100 wt. % of the total weight of the liquid toner, a latent electrostatic image formed on a photoconductor can be developed to a toner image.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: February 1, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuo Tsubuko, Akihiko Gotoh, Tsuyoshi Asami, Yukio Tabata
  • Patent number: 5952048
    Abstract: An ink composition contains a carrier medium and charged particles containing a coloring agent, which ink composition satisfies at least one condition of condition A or B: condition A that the specific charge quantity of the charged particles is in a range of 10 to 1,000 .mu.C/g with a positive or negative polarity; and condition B that the specific resistance of the ink composition is 10.sup.10 .OMEGA.cm or more; and ink-jet recording methods using the ink composition are proposed.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: September 14, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuo Tsubuko, Nobutaka Kinoshita, Tsuyoshi Asami, Akihiko Gotoh, Kazuhiko Umemura, Kazuyo Mizuno, Makoto Okawara
  • Patent number: 5851717
    Abstract: A developer for use in electrophotography for developing latent electrostatic images to visible toner images, includes at least two kinds of toner particles with different shapes selected from the group consisting of spherical toner particles, fibrous toner particles and amorphous toner particles, each toner particle containing a coloring agent and a binder resin. There is provided a liquid developer including a toner which is dispersed in a carrier liquid, in which the toner includes at least two kinds of the above-mentioned toner particles with different shapes. An electrophotographic image formation method using the above-mentioned liquid developer is also provided.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: December 22, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuo Tsubuko, Akihiko Gotoh, Tsuyoshi Asami, Kazuyo Mizuno, Akihiro Koseki
  • Patent number: 5204207
    Abstract: A magenta color liquid developer for electrophotography composed of a carrier liquid and toner particles dispersed in the carrier liquid, which toner particles contain a resin and two or more pigments including at least one water-insoluble azo pigment and a quinacridone-type pigment.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: April 20, 1993
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamashita, Akihiko Gotoh