Patents by Inventor Tomoharu Asano

Tomoharu Asano 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: 9671706
    Abstract: An electrophotographic photoconductor including a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer is provided. The undercoat layer includes zinc oxide particles and a binder resin. The undercoat layer has a voltage (V)-current (I) characteristics such that, when S1 is a value obtained by integrating current (I [A]) in terms of voltage (V [V]) from 0 to a distribution voltage VUL [V] distributed to the undercoat layer, and S2 is a value obtained by integrating a line connecting two points at a voltage (V [V]) of 0 and the distribution voltage VUL [V] in terms of voltage (V [V]) from 0 to the distribution voltage VUL [V], S1 is within a range of from 1.0×10?4 to 1.0×10?2 and a ratio (S1/S2) of S1 to S2 is 0.50 or less.
    Type: Grant
    Filed: March 26, 2015
    Date of Patent: June 6, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Nii, Eiji Kurimoto, Tetsuro Suzuki, Tomoharu Asano, Toshihiro Ishida
  • Publication number: 20170153559
    Abstract: A photoconductor includes an electroconductive substrate; an undercoat layer overlying the electroconductive substrate; and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a urethane resin, a metal oxide particle and a compound having the following formula (1): wherein R1 to R8 independently represent a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or an unsaturated aliphatic hydrocarbon group optionally having a substituent, an aromatic hydrocarbon group optionally having a substituent, an alkoxy group optionally having a substituent, an aryloxy group optionally having a substituent, a sulfo group optionally having a substituent, an amino group, a dialkylamino group optionally having a substituent or an diarylamino group optionally having a substituent; and R3 and R4, R4 and R5, R6 and R7, and R7 and R8 may be bonded with each other to form an aromatic ring.
    Type: Application
    Filed: October 21, 2016
    Publication date: June 1, 2017
    Inventors: Tomoharu ASANO, Eiji Kurimoto, Tetsuro Suzuki, Daisuke Nii, Toshihiro Ishida
  • Patent number: 9599916
    Abstract: An electrophotographic photoreceptor includes a substrate, an undercoat layer overlying the substrate, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a binder resin, a metal oxide particle and a compound having a thiol group.
    Type: Grant
    Filed: November 5, 2015
    Date of Patent: March 21, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Eiji Kurimoto, Tetsuro Suzuki, Daisuke Nii, Toshihiro Ishida
  • Publication number: 20160334720
    Abstract: A photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, the undercoat layer being disposed over the conductive support, the photoconductive layer being disposed over the undercoat layer, wherein the undercoat layer includes zinc oxide particles, wherein when a film thickness of the undercoat layer is 20 ?m, the undercoat layer has transmittance of 50% or more to light having a wavelength in a range of 500 nm or more but 800 nm or less, wherein a lowest transmittance of light is 85% or less in the range, and wherein when an electric field of 5 V/?m is applied to the undercoat layer, volume resistivity of the undercoat layer is 1.0×107 ?·cm or more but 5.0×108 ?·cm or less at an environment of 23° C. and 55% RH.
    Type: Application
    Filed: May 2, 2016
    Publication date: November 17, 2016
    Inventors: Toshihiro Ishida, Eiji Kurimoto, Tetsuro Suzuki, Tomoharu Asano, Daisuke Nii
  • Publication number: 20160327877
    Abstract: Provided is a photoconductor including a conductive support, an intermediate layer containing metal oxide particles, and a photoconductive layer. The intermediate layer and the photoconductive layer are provided over the conductive support in the order of reciting. An elastic power (We/Wt value) of the intermediate layer is greater than or equal to 20.0% but less than 35.0%. A Martens hardness (HM) of the intermediate layer is greater than or equal to 350 [N/mm2] but less than 450 [N/mm2].
    Type: Application
    Filed: April 20, 2016
    Publication date: November 10, 2016
    Inventors: Eiji KURIMOTO, Tetsuro SUZUKI, Tomoharu ASANO, Daisuke NII, Toshihiro ISHIDA
  • Publication number: 20160161871
    Abstract: An electrophotographic photoreceptor includes a substrate, an undercoat layer overlying the substrate, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a binder resin, a metal oxide particle and a compound having a thiol group.
    Type: Application
    Filed: November 5, 2015
    Publication date: June 9, 2016
    Inventors: Tomoharu ASANO, Eiji Kurimoto, Tetsuro Suzuki, Daisuke Nii, Toshihiro Ishida
  • Publication number: 20160139517
    Abstract: A electrophotographic photoconductor is provided. The electrophotographic photoconductor includes a conductive support, an undercoat layer overlying the conductive support, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a metal oxide particle, binder resin, and a compound having a urea group.
    Type: Application
    Filed: November 19, 2015
    Publication date: May 19, 2016
    Inventors: Toshihiro ISHIDA, Eiji Kurimoto, Tetsuro Suzuki, Tomoharu Asano, Daisuke Nii
  • Patent number: 9291924
    Abstract: A photoconductor is provided. The photoconductor includes an electroconductive substrate; an intermediate layer located overlying the electroconductive substrate; and a photosensitive layer located overlying the intermediate layer. The intermediate layer includes at least a resin, and a particulate zinc oxide that includes sodium, sulfur and calcium in amounts of from 10 ppm to 200 ppm, from 50 ppm to 500 ppm, and from 10 ppm to 200 ppm, respectively.
    Type: Grant
    Filed: December 2, 2014
    Date of Patent: March 22, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Eiji Kurimoto, Tetsuro Suzuki, Tomoharu Asano, Daisuke Nii, Toshihiro Ishida
  • Publication number: 20150309430
    Abstract: An electrophotographic photoconductor including a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer is provided. The undercoat layer includes zinc oxide particles and a binder resin. The undercoat layer has a voltage (V)-current (I) characteristics such that, when S1 is a value obtained by integrating current (I[A]) in terms of voltage (V[V]) from 0 to a distribution voltage VUL[V] distributed to the undercoat layer, and S2 is a value obtained by integrating a line connecting two points at a voltage (V[V]) of 0 and the distribution voltage VUL[V] in terms of voltage (V[V]) from 0 to the distribution voltage VUL[V], S1 is within a range of from 1.0×10?4 to 1.0×10?2 and a ratio (S1/S2) of S1 to S2 is 0.50 or less.
    Type: Application
    Filed: March 26, 2015
    Publication date: October 29, 2015
    Inventors: Daisuke NII, Eiji Kurimoto, Tetsuro Suzuki, Tomoharu Asano, Toshihiro Ishida
  • Patent number: 9146483
    Abstract: In a photoreceptor including an electroconductive substrate; a photosensitive layer; and a protective layer, the protective layer includes a crosslinked resin having a residual group of a polycarboxylic acid compound and a group having the below-mentioned formula (10), and at least one of a compound having the below-mentioned formula (2) and a compound having the below-mentioned formula (3). wherein each of R5 and R6 independently represents a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms. wherein each of R7 and R8 independently represents a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, and Z1 represents a vinylene group, a divalent aromatic hydrocarbon group having 6 to 14 carbon atoms, or a 2,5-thiophenediyl group.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: September 29, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuaki Hirose, Akihiro Sugino, Noboru Toriu, Keisuke Shimoyama, Tomoharu Asano
  • Publication number: 20150168856
    Abstract: A photoconductor is provided. The photoconductor includes an electroconductive substrate; an intermediate layer located overlying the electroconductive substrate; and a photosensitive layer located overlying the intermediate layer. The intermediate layer includes at least a resin, and a particulate zinc oxide that includes sodium, sulfur and calcium in amounts of from 10 ppm to 200 ppm, from 50 ppm to 500 ppm, and from 10 ppm to 200 ppm, respectively.
    Type: Application
    Filed: December 2, 2014
    Publication date: June 18, 2015
    Inventors: Eiji KURIMOTO, Tetsuro SUZUKI, Tomoharu ASANO, Daisuke NII, Toshihiro ISHIDA
  • Patent number: 9031491
    Abstract: An image forming apparatus, including a photoreceptor; a charger; an irradiator; an image developer; a transferer; a fixer; and a cleaning blade formed of a strip-shaped elastic blade, removing a powder from the surface of the photoreceptor passing an edge line of the blade while contacting thereto, wherein the photoreceptor includes a crosslinked resin surface layer formed of at least one of an acrylic resin and a methacrylic resin, and the cleaning blade includes a contact point with the photoreceptor, including a substrate; a mixed layer formed of at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.
    Type: Grant
    Filed: February 12, 2013
    Date of Patent: May 12, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Hideo Nakamori, Akihiro Sugino, Noboru Toriu, Keisuke Shimoyama, Mitsuaki Hirose, Yohta Sakon, Masahiro Ohmori
  • Publication number: 20140234763
    Abstract: An image forming apparatus includes an image bearing member having a photosensitive layer and a sub-surface layer having a charge transportability, overlying the photosensitive layer wherein the sub-surface layer is formed of a cured material formed of a radical polymerizable monomer having three or more functional groups with no charge transport structure and a radical polymerizable compound having a charge transport structure, wherein the arithmetical mean roughness WRa of about each of frequency components of HMH, HML, and HLH obtained by wavelet conversion of values measured by a surface texture and the contour form measuring device ranges from 0.0002 ?m to 0.005 ?m and WRa (LLH) is 0.05 ?m or less, wherein the sub-surface layer contains at least one of a particular oxazole compound or a particular diamine compound.
    Type: Application
    Filed: February 6, 2014
    Publication date: August 21, 2014
    Inventors: Akihiro SUGINO, Keisuke Shimoyama, Tomoharu Asano, Hidetoshi Kami, Nobutaka Eguchi, Kazuhiro Egawa, Tomoyuki Shimada, Ryota Arai, Masayoshi Nomura
  • Patent number: 8798487
    Abstract: An image forming apparatus having an image bearing member, a charger to charge the surface of the image bearing member, an irradiator to irradiate the image bearing member to form the latent image, a developing device to develop the latent electrostatic image with toner to obtain a visible image, a transfer device to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member, and a voltage detector to measure a first surface voltage and a second surface voltage under different conditions, and a life expectancy identification device to identify whether or when the expected working life of the image bearing member has come to the end based on a comparison of the first surface voltage and the second surface voltage.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: August 5, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Takaaki Ikegami, Michio Kimura
  • Patent number: 8652717
    Abstract: An image bearing member having an electroconductive substrate, a photosensitive layer overlying the electroconductive layer, and a cross-linked surface layer overlying the photosensitive layer, which contains a cross-linked polymer and a first compound consisting essentially of a nitrogen atom and a phenyl group, biphenyl group, and condensed polycyclic hydrocarbon group, or a second compound consisting essentially of a nitrogen atom and hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, or aryl groups, substituted or non-substituted alkyl groups, substituted or non-substituted alkoxy groups, substituted or non-substituted aralkyl groups, substituted or non-substituted aryl group, substituted or non-substituted alkylene groups, cyano groups, nitro groups, or —OCO?CH2R16, in which R16 represents a hydrogen atom, a substituted or non-substituted alkyl group, a substituted or non-substituted alkoxy group, or a substituted or non-substituted aryl group.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Keisuke Shimoyama, Hiroshi Ikuno, Tetsuya Toshine, Tomoharu Asano, Yasuhito Kuboshima, Yuuji Tanaka
  • Patent number: 8647798
    Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer on the electroconductive substrate; and a protection layer on the photosensitive layer, wherein the protection layer includes a radical polymerizable compound having three or more radical polymerizable groups without a charge transportable group, a monofunctional radical polymerizable compound having a specific charge transportable group and a non-radical polymerizable compound having a specific charge transportable group.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: February 11, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Hiroshi Ikuno, Akihiro Sugino, Hideo Nakamori, Mitsuaki Hirose
  • Publication number: 20130330104
    Abstract: A photoreceptor includes an electroconductive substrate, and a laminate structure formed of at least a charge generating layer and a charge transport layer and provided overlying the electroconductive substrate, wherein the charge transport layer contains a charge transport material, a compound represented by the following formula 1 and a compound represented by the following formula 2: in the formula 1, R1 and R2 each independently represent substituted or non-substituted alkyl groups or aromatic hydrocarbon groups and one of R1 and R2 represents a substituted or non-substituted aromatic hydrocarbon group, R1 and R2 bonded to the same nitrogen atom may be bonded together to form a substituted or non-substituted nitrogen-containing heterocyclic group, and Ar represents a substituted or non-substituted hydrocarbon group; in the formula 2, R3 and R4 each independently represent substituted or non-substituted alkyl groups or aromatic hydrocarbon groups.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 12, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Keisuke Shimoyama, Akihiro Sugino, Mitsuaki Hirose, Tomoharu Asano, Noboru Toriu, Hideo Nakamori
  • Publication number: 20130251401
    Abstract: An image forming apparatus, including a photoreceptor; a charger; an irradiator; an image developer; a transferer; a fixer; and a cleaning blade formed of a strip-shaped elastic blade, removing a powder from the surface of the photoreceptor passing an edge line of the blade while contacting thereto, wherein the photoreceptor includes a crosslinked resin surface layer formed of at least one of an acrylic resin and a methacrylic resin, and the cleaning blade includes a contact point with the photoreceptor, including a substrate; a mixed layer formed of at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.
    Type: Application
    Filed: February 12, 2013
    Publication date: September 26, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Tomoharu Asano, Hideo Nakamori, Akihiro Sugino, Noboru Toriu, Keisuke Shimoyama, Mitsuaki Hirose, Yohta Sakon, Masahiro Ohmori
  • Publication number: 20130243483
    Abstract: In a photoreceptor including an electroconductive substrate; a photosensitive layer; and a protective layer, the protective layer includes a crosslinked resin having a residual group of a polycarboxylic acid compound and a group having the below-mentioned formula (10), and at least one of a compound having the below-mentioned formula (2) and a compound having the below-mentioned formula (3). wherein each of R5 and R6 independently represents a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms. wherein each of R7 and R8 independently represents a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, and Z1 represents a vinylene group, a divalent aromatic hydrocarbon group having 6 to 14 carbon atoms, or a 2,5-thiophenediyl group.
    Type: Application
    Filed: February 20, 2013
    Publication date: September 19, 2013
    Inventors: Mitsuaki HIROSE, Akihiro Sugino, Noboru Toriu, Keisuke Shimoyama, Tomoharu Asano
  • Patent number: 8535863
    Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer located overlying the electroconductive substrate; and a crosslinked outermost layer located overlying the photosensitive layer and including a crosslinked material and a specific carbazole compound serving as a charge transport material. An image forming apparatus including the photoreceptor; a charger to charge the photoreceptor; an irradiator to irradiate the charged photoreceptor to form an electrostatic latent image thereon; a developing device to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor; and a transferring device to transfer the toner image onto a recording material.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: September 17, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Asano, Hiroshi Ikuno, Yasuhito Kuboshima, Yuuji Tanaka