Patents by Inventor Tamotsu Aruga

Tamotsu Aruga 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).

  • Publication number: 20070221079
    Abstract: The object of the present invention is to provide a recording ink having excellent color developing properties and high delivery stability, by which not only the color saturation of the obtained image can be remarkably improved, but also the image having a high quality can be formed. For this object, the present invention provides a recording ink used for an inkjet recording using a dye ink and a pigment ink properly alternately through one inkjet head, wherein the dye ink and the pigment ink have respectively a viscosity at 25° C. of 5 mPa·s or more and the difference between the viscosity of the dye ink and the viscosity of the pigment ink is 3 mPa·s or less.
    Type: Application
    Filed: April 6, 2005
    Publication date: September 27, 2007
    Inventors: Tamotsu Aruga, Kiyofumi Nagai
  • Publication number: 20070197685
    Abstract: A recording ink containing at least a solid component which contains a colorant and a resin and is a solid at 25° C., a liquid component which has a higher boiling point than that of water and is a liquid at 25° C. and water, wherein the total content of the liquid component in the recording ink is 20% by mass or less, the total content of the solid component in the recording ink is 20% by mass or more, and the total content of a resin component in the solid component is 40% by mass to 95% by mass relative to a total amount of the solid component is provided.
    Type: Application
    Filed: January 17, 2007
    Publication date: August 23, 2007
    Inventors: Tamotsu Aruga, Masayuki Koyano, Akihiko Matsuyama, Hisashi Habashi, Hiroshi Goto, Tohru Ohshima, Naoya Morohoshi, Kiyofumi Nagai
  • Publication number: 20060279603
    Abstract: An image forming apparatus having a recording head for discharging an ink includes a fuel cell unit and a water supply unit. The fuel cell unit generates power for the image forming apparatus and water when the power is generated in the fuel cell unit. The water supply unit supplies the water, generated by the fuel cell unit, to an ink accumulation area in the image forming apparatus.
    Type: Application
    Filed: June 8, 2006
    Publication date: December 14, 2006
    Inventors: Masanori Kusunoki, Noriyasu Takeuchi, Kunihiro Yamanaka, Tamotsu Aruga, Hiroshi Adachi
  • Patent number: 6699631
    Abstract: An image forming apparatus including a photoconductor, and an exposing device for irradiating a surface of the photoconductor imagewise with a coherent light to form an electrostatic latent image thereon. The surface of the photoconductor has such roughness as to provide I(S) of at least 3.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: March 2, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuka Miyamoto, Toshiyuki Kabata, Tamotsu Aruga
  • Patent number: 6558863
    Abstract: A photoreceptor including an electroconductive substrate and a photosensitive layer which is formed on the electroconductive substrate and which includes a charge generation material, wherein the charge generation material comprises an organic pigment and wherein the photosensitive layer further includes at least one ion selected from the group consisting of K+, Na+, NO3−, HCOO−, NO2−, Cl−, Br−, and NH4+ or one or more water-soluble inorganic salts.
    Type: Grant
    Filed: December 13, 2000
    Date of Patent: May 6, 2003
    Assignee: Ricoh Company Limited
    Inventors: Takashi Rokutanzono, Tamotsu Aruga, Tatsuya Niimi, Yoshiaki Kawasaki
  • Publication number: 20020160287
    Abstract: An image forming apparatus including a photoconductor, and an exposing device for irradiating a surface of the photoconductor imagewise with a coherent light to form an electrostatic latent image thereon. The surface of the photoconductor has such roughness as to provide I(S) of at least 3.
    Type: Application
    Filed: February 20, 2002
    Publication date: October 31, 2002
    Inventors: Yuka Miyamoto, Toshiyuki Kabata, Tamotsu Aruga
  • Patent number: 6355390
    Abstract: An electrophotographic photoconductor has an electroconductive support, and an undercoat layer and a photoconductive layer which are successively overlaid on the support, the undercoat layer containing an inorganic pigment and a crosslinked N-alkoxymethylated polyamide or a crosslinked material of an N-alkoxymethylated polyamide and a melamine resin as a binder resin. The method of producing the photoconductor is also disclosed. An electrophotographic image forming apparatus is provided with the aforementioned photoconductor, a charging unit, and a developing unit. A process cartridge is provided with the photoconductor, and at least one of a charging unit, a light exposure unit, a developing unit, or an image transfer unit. An electrophotographic image forming process has the steps of forming a latent electrostatic image on the photoconductor, and developing the latent electrostatic image to a visible image by reversal development.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: March 12, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Hirofumi Yamanami, Tamotsu Aruga
  • Patent number: 6316577
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (I), two structural units of formulae (I) and (II), or a repeat unit of formula (III): wherein Ar1 to Ar7, Y, X, and n are as specified in the specification.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: November 13, 2001
    Assignee: Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Masafumi Ohta, Akihiro Imai, Mitsutoshi Anzai, Tamotsu Aruga, Kazukiyo Nagai, Katsuhiro Morooka
  • Publication number: 20010016296
    Abstract: A photoreceptor including an electroconductive substrate and a photosensitive layer which is formed on the electroconductive substrate and which includes a charge generation material, wherein the charge generation material comprises an organic pigment and wherein the photosensitive layer further includes at least one ion selected from the group consisting of K+, Na+, NO3−, HCOO−, NO2−, Cl−, Br−, and NH4+ or one or more water-soluble inorganic salts.
    Type: Application
    Filed: December 13, 2000
    Publication date: August 23, 2001
    Applicant: Ricoh Company Limited
    Inventors: Takashi Rokutanzono, Tamotsu Aruga, Tatsuya Niimi, Yoshiaki Kawasaki
  • Patent number: 6027846
    Abstract: An electrophotographic photoconductor includes an electroconductive support, and a photoconductive layer formed thereon containing as an effective component an aromatic polycarbonate resin having a structural unit of formula (I), two structural units of formulae (I) and (II), or a repeat unit of formula (III): ##STR1## wherein Ar.sup.1 to Ar.sup.7, Y, X, and n are as specified in the specification.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: February 22, 2000
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Masafumi Ohta, Akihiro Imai, Mitsutoshi Anzai, Tamotsu Aruga, Kazukiyo Nagai, Katsuhiro Morooka
  • Patent number: 5863683
    Abstract: An electrophotographic photoconductor composed of an electroconductive support and a photoconductive layer formed thereon, which contains as a charge generating material an azo pigment subjected to a salt milling process.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: January 26, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsuichi Ohta, Masaomi Sasaki, Tamotsu Aruga
  • Patent number: 5672728
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, w, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: September 30, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5672756
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, and a photoconductive layer formed thereon containing at least one tertiary amine compound of formula (I) as an effective component: ##STR1## wherein Ar.sup.1 and Ar.sup.3 each is an aryl group which may have a substituent; Ar.sup.2 is a bivalent group of a carboxylic aromatic compound or a bivalent group of a heterocyclic compound; R.sup.1 is a hydrogen atom, an alkyl group which may have a substituent or an alkoxy group which may have a substituent; and R.sup.2 is a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent. A novel triphenylamine compound for use in the electrophotographic photoconductor is provided.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: September 30, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga, Masafumi Ohta, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5631404
    Abstract: An electrophotographic photoconductor includes an electroconductive support and a photoconductive layer formed thereon containing a diamine compound represented by formula (I): ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 each is independently a substituted or unsubstituted alkyl group or aryl group; R.sup.4 is hydrogen, an alkyl group or an alkoxyl group; n is an integer of 1 to 3; and ##STR2## is a substituted or unsubstituted bivalent arylene group or a bivalent heterocyclic group. This diamine compound is useful as a photoconductive material for electrophotographic photoconductors.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: May 20, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Mitsutoshi Anzai, Yasuo Murakami, Atsushi Takesue, Masaomi Sasaki, Tomoyuki Shimada, Tamotsu Aruga, Masafumi Ohta
  • Patent number: 5616805
    Abstract: A pyrenylamine derivative having an unsaturated bond formula (I), which can be employed as an organic photoconductive material for use in electrophotography: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, l, m, n, j and k are specifically defined in the specification, an aldehyde compound of formula (II), which is an intermediate for preparing the pyrenylamine derivative: ##STR2## and methods of producing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: April 1, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5616801
    Abstract: Charge transporting materials having general formula (I): ##STR1## wherein R.sup.1 represents hydrogen; an unsubstituted or substituted alkyl group; an alkoxyl group having 1 to 4 carbon atoms; a thioalkoxyl group having 1 to 4 carbon atoms; an aryloxy group; an aralkyl group; a nitro group; an unsubstituted or substituted aryl group; a halogen; an amino group; an unsubstituted or substituted dialkylamino group; R.sup.2 represents hydrogen; an unsubstituted or substituted alkyl group; an alkoxyl group having 1 to 4 carbon atoms; or a halogen; R.sup.3 represents hydrogen; an alkyl group having 1 to 4 carbon atoms; an alkoxyl group having 1 to 4 carbon atoms; a halogen; a dialkylamino group; an amino group; a thioalkoxyl group having 1 to 4 carbon atoms; an aryloxy group; a methylenedioxy group; an aralkyl group; or an unsubstituted or substituted aryl group; represents R.sup.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: April 1, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Mitsuru Hashimoto, Tamotsu Aruga
  • Patent number: 5604065
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, and a photoconductive layer formed thereon containing at least one tertiary amine compound of formula (I) as an effective component: ##STR1## wherein Ar.sup.1 and Ar.sup.3 each is an aryl group which may have a substituent; Ar.sup.2 is a bivalent group of a carbocyclic aromatic compound or a bivalent group of a heterocyclic compound; R.sup.1 is a hydrogen atom, an alkyl group which may have a substituent or an alkoxyl group which may have a substituent; and R.sup.2 is a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent. A novel triphenylamine compound for use in the electrophotographic photoconductor is provided.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: February 18, 1997
    Assignees: Ricoh Company, Ltd., Hodogaya Chemical Co., Ltd.
    Inventors: Tomoyuki Shimada, Masaomi Sasaki, Tamotsu Aruga, Masafumi Ohta, Mitsutoshi Anzai, Akihiro Imai
  • Patent number: 5599995
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: February 4, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5587516
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: December 24, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi
  • Patent number: 5576132
    Abstract: An electrophotographic photoconductor comprises an electroconductive substrate and a photoconductive layer formed thereon comprising as an effective component at least one pyrenylamine derivative of formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, W, j, k, l, m and n are specifically defined in the specification. Furthermore, a novel pyrenylamine derivative for use in the above electrophotographic photoconductor, an aldehyde compound, which is an intermediate for producing the pyrenylamine derivative, and methods of preparing the pyrenylamine derivative and the aldehyde compound are disclosed.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: November 19, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Chiaki Tanaka, Masaomi Sasaki, Tamotsu Aruga, Tomoyuki Shimada, Hiroshi Adachi