Patents by Inventor Keiji Maruo

Keiji Maruo 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: 9141007
    Abstract: Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (?max) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A850) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 ?m?1 or less.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: September 22, 2015
    Assignee: Kyocera Mita Corporation
    Inventors: Kazunari Hamasaki, Yuko Iwashita, Daisuke Kuboshima, Keiji Maruo, Shiho Kuboshima
  • Patent number: 9023564
    Abstract: The present disclosure relates to an azoquinone compound represented by formula (1) below. In formula (1), R1 to R4 are identical or different and each represents a hydrogen atom, a C1 to C6 alkyl group or a C6 to C12 aryl group, and Ar represents a C6 to C12 aryl group.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: May 5, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Hideki Okada, Keiji Maruo
  • Publication number: 20150037069
    Abstract: An electrophotographic photosensitive member containing a terphenoquinone derivative represented by the following formula (1): wherein R1 to R5 may be the same or different and each represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms and optionally having an alkyl group having 1 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an alkoxy group having 2 to 6 carbon atoms.
    Type: Application
    Filed: July 28, 2014
    Publication date: February 5, 2015
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Hideki OKADA, Keiji MARUO
  • Publication number: 20140356773
    Abstract: An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, and a binder resin. The hole transport material contains an amine stilbene derivative represented by a general formula (1), and the binder resin contains a polycarbonate resin represented by a general formula (2).
    Type: Application
    Filed: May 28, 2014
    Publication date: December 4, 2014
    Applicant: KYOCERA DOCUMENTS SOLUTIONS, INC.
    Inventors: Jun AZUMA, Keiji MARUO, Kensuke OKAWA, Akihiko OGATA
  • Publication number: 20140295335
    Abstract: The present disclosure relates to an azoquinone compound represented by formula (1) below. In formula (1), R1 to R4 are identical or different and each represents a hydrogen atom, a C1 to C6 alkyl group or a C6 to C12 aryl group, and Ar represents a C6 to C12 aryl group.
    Type: Application
    Filed: March 26, 2014
    Publication date: October 2, 2014
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Hideki Okada, Keiji Maruo
  • Patent number: 8765337
    Abstract: The present invention is to provide a multilayer type electrophotographic photoconductor capable of stably obtaining a high image quality image over a long term by restraining the exposure memory and the photo memory, and an image forming apparatus comprising such a multilayer type electrophotographic photoconductor. A multilayer type electrophotographic photoconductor comprising a charge generating layer containing at least a charge generating agent on a base member directly or via an intermediate layer, and a charge transporting layer containing at least a charge transporting agent and a binder resin formed successively, wherein the light absorption degree at a 680 nm wavelength light beam in the photoconductive layer of the multilayer type electrophotographic photoconductor is of a value of 0.8 or less, and the light absorption degree at a 450 nm wavelength light beam is of a value of 1.
    Type: Grant
    Filed: May 24, 2007
    Date of Patent: July 1, 2014
    Assignee: Kyocera Mita Corporation
    Inventors: Keiji Maruo, Junichiro Otsubo, Jun Azuma
  • Patent number: 8686133
    Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: April 1, 2014
    Assignee: Kyocera Document Solutions Inc.
    Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
  • Patent number: 8679710
    Abstract: The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a prede mulas (A) and (B). The electrophotographic photoreceptor prevents image defect termined additive. The hole transport agent satisfies the following for from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. ? ? M < 1.2 × 10 - 8 ( A ) ? ? > 5.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: March 25, 2014
    Assignee: Kyocera Document Solutions Inc.
    Inventors: Daisuke Kuboshima, Eiichi Miyamoto, Kazunari Hamasaki, Norio Nakai, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
  • Publication number: 20120296082
    Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor the oxo-titanylphthalocyanine crystal has predetermined optical characteristics and thermal properties and is produced by a production method including the following steps (a) to (d): (a) a step of dissolving a crude oxo-titanylphthalocyanine crystal in an acid to obtain an oxo-titanylphthalocyanine solution; (b) a step of adding the oxo-titanylphthalocyanine solution dropwise in a poor solvent to obtain a wet cake; (c) a step of washing the wet cake with an alcohol having 1 to 4 carbon atoms; and (d) a step of stirring the washed wet cake under heating in a nonaqueous solvent to obtain an oxo-titanylphthalocya
    Type: Application
    Filed: July 11, 2012
    Publication date: November 22, 2012
    Inventors: Daisuke KUBOSHIMA, Jun AZUMA, Yoshio INAGAKI, Junichiro OTSUBO, Keiji MARUO
  • Patent number: 8242261
    Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: August 14, 2012
    Assignee: Kyocera Mita Corporation
    Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
  • Publication number: 20110046392
    Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.
    Type: Application
    Filed: October 1, 2010
    Publication date: February 24, 2011
    Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
  • Patent number: 7700251
    Abstract: An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate.
    Type: Grant
    Filed: October 18, 2006
    Date of Patent: April 20, 2010
    Assignee: Kyocera Mita Corporation
    Inventors: Norio Nakai, Kazunari Hamasaki, Daisuke Kuboshima, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
  • Publication number: 20080305418
    Abstract: Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (?max) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A850) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 ?m?1 or less.
    Type: Application
    Filed: March 13, 2008
    Publication date: December 11, 2008
    Applicant: Kyocera Mita Corporation
    Inventors: Kazunari Hamasaki, Yuko Iwashita, Daisuke Kuboshima, Keiji Maruo, Shiho Kuboshima
  • Publication number: 20080050666
    Abstract: To provide an electrophotographic photoconductor which can effectively prevent the generation of exposure memory and the increase in residual potential by easily adjusting the electroconductivity in an intermediate layer, and an image forming apparatus using the electrophotographic photoconductor. An electrophotographic photoconductor comprising a base body, and an intermediate layer containing a titanium oxide and a binding resin and a photosensitive layer which are arranged on the base body, and an image forming apparatus using the same, wherein an average primary particle diameter of the titanium oxide is set to a value within the range of 5 to 30 nm, a thickness of the intermediate layer set to a value within the range of 0.5 to 3 ?m, and the volume resistivity in the intermediate layer is set to a value within the range of 1×1010 to 5×1013 ?·cm.
    Type: Application
    Filed: August 14, 2007
    Publication date: February 28, 2008
    Inventors: Junichiro Otsubo, Jun Azuma, Keiji Maruo, Yoshio Inagaki
  • Publication number: 20080026310
    Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.
    Type: Application
    Filed: July 10, 2007
    Publication date: January 31, 2008
    Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
  • Publication number: 20070281227
    Abstract: The present invention is to provide a multilayer type electrophotographic photoconductor capable of stably obtaining a high image quality image over a long term by restraining the exposure memory and the photo memory, and an image forming apparatus comprising such a multilayer type electrophotographic photoconductor. A multilayer type electrophotographic photoconductor comprising a charge generating layer containing at least a charge generating agent on a base member directly or via an intermediate layer, and a charge transporting layer containing at least a charge transporting agent and a binder resin formed successively, wherein the light absorption degree at a 680 nm wavelength light beam in the photoconductive layer of the multilayer type electrophotographic photoconductor is of a value of 0.8 or less, and the light absorption degree at a 450 nm wavelength light beam is of a value of 1.
    Type: Application
    Filed: May 24, 2007
    Publication date: December 6, 2007
    Inventors: Keiji Maruo, Junichiro Otsubo, Jun Azuma
  • Publication number: 20070111118
    Abstract: An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate.
    Type: Application
    Filed: October 18, 2006
    Publication date: May 17, 2007
    Inventors: Norio Nakai, Kazunari Hamasaki, Daisuke Kuboshima, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
  • Publication number: 20070077507
    Abstract: The present invention provides an electrophotographic photoconductor which can reduce the generation of fogging under a high-temperature and high-moisture condition and can be easily manufactured, and a method of manufacturing such an electrophotographic photoconductor. In an electrophotographic photoconductor which includes a support base body, an intermediate layer and a photoconductor layer and a manufacturing method of such an electrophotographic photoconductor, the intermediate layer contains titanium oxide and a binding resin and a ?L value of the intermediate layer satisfies a following relationship formula (1) or a ?A value of the intermediate layer satisfies a following relationship formula (2), that is, ?5.0??L?0 (1) and ?A?0.
    Type: Application
    Filed: September 19, 2006
    Publication date: April 5, 2007
    Inventors: Junichiro Otsubo, Jun Azuma, Keiji Maruo, Yoshio Inagaki, Norio Nakai, Kazunari Hamasaki, Shiho Okawa
  • Publication number: 20060141377
    Abstract: The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a predetermined additive. The hole transport agent satisfies the following formulas (A) and (B). The electrophotographic photoreceptor prevents image defect from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. ? ? ? M < 1.2 × 10 - 8 ( A ) ? ? ? > 5.
    Type: Application
    Filed: December 22, 2005
    Publication date: June 29, 2006
    Inventors: Daisuke Kuboshima, Eiichi Miyamoto, Kazunari Hamasaki, Norio Nakai, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo