Patents by Inventor Kensuke Okawa

Kensuke Okawa 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: 10871723
    Abstract: An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3) disposed directly or indirectly on the conductive substrate (2). The photosensitive layer (3) has a charge generating layer (3a) and a charge transport layer (3b) disposed in order from the conductive substrate (2). The charge generating layer (3a) contains a charge generating material. The charge transport layer (3b) contains a charge transport material, a binder resin, and a pigment that absorbs light having an irradiation wavelength.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: December 22, 2020
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Kensuke Okawa, Seiki Hasunuma, Jun Azuma
  • Patent number: 10761439
    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 binder resin contains a polyarylate resin represented by general formula (1). In general formula (1), r and s each represent an integer of at least 0 and no greater than 49 and t and u represents an integer of at least 1 and no greater than 50. Furthermore, r+s+t+u=100 and r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4).
    Type: Grant
    Filed: August 4, 2017
    Date of Patent: September 1, 2020
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Kensuke Okawa, Seiki Hasunuma, Tomofumi Shimizu
  • Publication number: 20200233321
    Abstract: An electrophotographic photosensitive member includes a conductive substrate, a charge generating layer, and a charge transport layer. The charge generating layer has a thickness of at least 0.07 ?m. The charge transport layer contains a binder resin, a hole transport material, and meta-terphenyl. The binder resin includes a polyarylate resin including repeating units and a group represented by respective general formulas (1) to (3). The electrophotographic photosensitive member satisfies at least two conditions of: (A) the charge generating layer has a thickness of at least 0.12 ?m; (B) the charge transport layer contains a specific amount of fluororesin particles; and (C) the charge transport layer contains meta-terphenyl in an amount of at least 5.0 parts by mass and no greater than 15.0 parts by mass relative to 100 parts by mass of the binder resin.
    Type: Application
    Filed: January 17, 2020
    Publication date: July 23, 2020
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazutaka SUGIMOTO, Kensuke OKAWA, Jun AZUMA
  • Publication number: 20200026207
    Abstract: An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3) disposed directly or indirectly on the conductive substrate (2). The photosensitive layer (3) has a charge generating layer (3a) and a charge transport layer (3b) disposed in order from the conductive substrate (2). The charge generating layer (3a) contains a charge generating material. The charge transport layer (3b) contains a charge transport material, a binder resin, and a pigment that absorbs light having an irradiation wavelength. The binder resin includes a polyarylate resin including a repeating unit represented by general formula (1): In general formula (1), X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1).
    Type: Application
    Filed: December 28, 2017
    Publication date: January 23, 2020
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kensuke OKAWA, Seiki HASUNUMA, Jun AZUMA
  • Patent number: 10379451
    Abstract: A polyarylate resin includes at least one type of repeating unit represented by a general formula (1), at least one type of repeating unit represented by a general formula (2), and a terminal group represented by a general formula (3). R1, R2, R3, and R4 each represent, independently of one another, a hydrogen atom or a methyl group. R5 and R6 each represent, independently of each other, a hydrogen atom or a C1-4 alkyl group. R5 and R6 may bond together to represent a C5-7 cycloalkylidene group. X1 represents a divalent group represented by a chemical formula (2A), (2B), (2C), or (2D) with the proviso that when only one type of repeating unit represented by the general formula (2) is included, X1 does not represent a divalent group represented by the chemical formula (2D). Rf represents a chain aliphatic group having at least one fluoro group.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: August 13, 2019
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Kensuke Okawa, Akihiko Ogata, Kenji Kitaguchi, Tomofumi Shimizu
  • Patent number: 10273331
    Abstract: A polyarylate resin is represented by general formula (1) shown below. In general formula (1), R1 and R2 each represent, independently of one another, a hydrogen atom or a methyl group. r and s each represent an integer of at least 0 and no greater than 49. t and u each represent an integer of at least 1 and no greater than 50. r+s+t+u=100. r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), chemical formula (1-2), chemical formula (1-3), or chemical formula (1-4). X and Y are different from one another.
    Type: Grant
    Filed: November 28, 2017
    Date of Patent: April 30, 2019
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Kenji Kitaguchi, Kensuke Okawa, Seiki Hasunuma, Tomofumi Shimizu
  • Publication number: 20180246424
    Abstract: A polyarylate resin includes at least one type of repeating unit represented by a general formula (1), at least one type of repeating unit represented by a general formula (2), and a terminal group represented by a general formula (3). R1, R2, R3, and R4 each represent, independently of one another, a hydrogen atom or a methyl group. R5 and R6 each represent, independently of each other, a hydrogen atom or a C1-4 alkyl group. R5 and R6 may bond together to represent a C5-7 cycloalkylidene group. X1 represents a divalent group represented by a chemical formula (2A), (2B), (2C), or (2D) with the proviso that when only one type of repeating unit represented by the general formula (2) is included, X1 does not represent a divalent group represented by the chemical formula (2D). Rf represents a chain aliphatic group having at least one fluoro group.
    Type: Application
    Filed: February 26, 2018
    Publication date: August 30, 2018
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Jun AZUMA, Kensuke OKAWA, Akihiko OGATA, Kenji KITAGUCHI, Tomofumi SHIMIZU
  • Patent number: 10031431
    Abstract: An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a charge transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin is represented by general formula (1) shown below. In general formula (1), X represents a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4) shown below.
    Type: Grant
    Filed: April 20, 2017
    Date of Patent: July 24, 2018
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Takahiro Oki, Kensuke Okawa, Akihiko Ogata
  • Publication number: 20180148538
    Abstract: A polyarylate resin is represented by general formula (1) shown below. In general formula (1), R1 and R2 each represent, independently of one another, a hydrogen atom or a methyl group. r and s each represent an integer of at least 0 and no greater than 49. t and u each represent an integer of at least 1 and no greater than 50. r+s+t+u=100. r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), chemical formula (1-2), chemical formula (1-3), or chemical formula (1-4). X and Y are different from one another.
    Type: Application
    Filed: November 28, 2017
    Publication date: May 31, 2018
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Jun AZUMA, Kenji KITAGUCHI, Kensuke OKAWA, Seiki HASUNUMA, Tomofumi SHIMIZU
  • Patent number: 9964869
    Abstract: A triarylamine derivative represented by general formula (1) below. In the general formula (1), R1, R2, R4, R5, R6, R7, R8, and R9 each represent, independently from one another, a hydrogen atom, an optionally substitute alkyl group having a carbon number of at least 1 and no greater than 6, an optionally substituted alkoxy group having a carbon number of at least 1 and no greater than 6, or an optionally substituted aryl group having a carbon number of at least 6 and no greater than 14, R3 represents an alkyl group having a carbon number of at least 1 and no greater than 4, X represents an alkylene group having a carbon number of at least 1 and no greater than 6 or an oxygen atom, and n represents an integer of 1 to 3.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: May 8, 2018
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Kensuke Okawa, Hideki Okada, Jun Azuma, Fumio Sugai, Kensuke Kojima
  • Patent number: 9939744
    Abstract: A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a charge transport material, a binder resin, and silica particles. The charge transport layer is a monolayer. The charge transport layer is disposed as an outermost surface layer of the multi-layer electrophotographic photosensitive member. The silica particles have a content of at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of the binder resin. The binder resin includes a polyarylate resin. The polyarylate resin has a repeating unit represented by general formula (I) shown below. In general formula (I), R1-R3 and Y are defined as those described in the specification.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: April 10, 2018
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Kensuke Okawa, Junichiro Otsubo, Akihiko Ogata
  • Patent number: 9933712
    Abstract: A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a hole transport material and a binder resin. The charge generating material contains a titanyl phthalocyanine that exhibits a main peak at a Bragg angle (2?±0.2°) of 27.2° in a CuK? characteristic X-ray diffraction spectrum. The hole transport material contains a triarylamine derivative represented by generic formula (1). The hole transport material has a mass ratio of at least 0.30 and no greater than 0.55 relative to the binder resin in the charge transport layer. In general formula (1), R1, R2, l, and m are the same as those defined in the specification.
    Type: Grant
    Filed: August 25, 2016
    Date of Patent: April 3, 2018
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Akihiko Ogata, Hideki Okada, Jun Azuma, Kensuke Okawa
  • Publication number: 20180046099
    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 binder resin contains a polyarylate resin represented by general formula (1). In general formula (1), r and s each represent an integer of at least 0 and no greater than 49 and t and u represents an integer of at least 1 and no greater than 50. Furthermore, r+s+t+u=100 and r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4).
    Type: Application
    Filed: August 4, 2017
    Publication date: February 15, 2018
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Jun AZUMA, Kensuke OKAWA, Seiki HASUNUMA, Tomofumi SHIMIZU
  • Publication number: 20170307989
    Abstract: An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a charge transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin is represented by general formula (1) shown below. In general formula (1), X represents a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4) shown below.
    Type: Application
    Filed: April 20, 2017
    Publication date: October 26, 2017
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Jun AZUMA, Takahiro OKI, Kensuke OKAWA, Akihiko OGATA
  • Publication number: 20170131647
    Abstract: A triarylamine derivative represented by general formula (1) below. In the general formula (1), R1, R2, R4, R5, R6, R7, R8, and R9 each represent, independently from one another, a hydrogen atom, an optionally substitute alkyl group having a carbon number of at least 1 and no greater than 6, an optionally substituted alkoxy group having a carbon number of at least 1 and no greater than 6, or an optionally substituted aryl group having a carbon number of at least 6 and no greater than 14, R3 represents an alkyl group having a carbon number of at least 1 and no greater than 4, X represents an alkylene group having a carbon number of at least 1 and no greater than 6 or an oxygen atom, and n represents an integer of 1 to 3.
    Type: Application
    Filed: November 8, 2016
    Publication date: May 11, 2017
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kensuke OKAWA, Hideki OKADA, Jun AZUMA, Fumio SUGAI, Kensuke KOJIMA
  • Patent number: 9625839
    Abstract: A photosensitive layer in a multilayer electrophotographic photoconductor includes a charge-generation layer including a charge-generating material having, as a major component, a titanyl phthalocyanine crystal which satisfies the conditions (A) and (B) below and a base resin, and a charge-transport layer including a charge-transporting material, the charge-generating material having, as a major component, the titanyl phthalocyanine crystal which has absorption at a wavelength of a charge-neutralizing light and which satisfies the conditions (A) and (B) or an X-form metal-free phthalocyanine crystal which has absorption at the wavelength of the charge-neutralizing light, and a binder resin. (A) In a Cu—K? characteristic X-ray diffraction spectrum, one peak is present at a Bragg angle 2?±0.2°=27.2°. (B) In a differential scanning calorimetry, one peak is present in a range of 270° C. to 400° C. except for peaks attributed to vaporization of adsorption water.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: April 18, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Makoto Shishido, Kensuke Okawa
  • Publication number: 20170068178
    Abstract: A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a charge transport material, a binder resin, and silica particles. The charge transport layer is a monolayer. The charge transport layer is disposed as an outermost surface layer of the multi-layer electrophotographic photosensitive member. The silica particles have a content of at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of the binder resin. The binder resin includes a polyarylate resin. The polyarylate resin has a repeating unit represented by general formula (I) shown below. In general formula (I), R1-R3 and Y are defined as those described in the specification.
    Type: Application
    Filed: September 1, 2016
    Publication date: March 9, 2017
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Jun AZUMA, Kensuke OKAWA, Junichiro OTSUBO, Akihiko OGATA
  • Publication number: 20170060006
    Abstract: A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a hole transport material and a binder resin. The charge generating material contains a titanyl phthalocyanine that exhibits a main peak at a Bragg angle (2?±0.2°) of 27.2° in a CuK? characteristic X-ray diffraction spectrum. The hole transport material contains a triarylamine derivative represented by generic formula (1). The hole transport material has a mass ratio of at least 0.30 and no greater than 0.55 relative to the binder resin in the charge transport layer. In general formula (1), R1, R2, l, and m are the same as those defined in the specification.
    Type: Application
    Filed: August 25, 2016
    Publication date: March 2, 2017
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Akihiko OGATA, Hideki OKADA, Jun AZUMA, Kensuke OKAWA
  • Patent number: 9575423
    Abstract: An electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer is a multi-layer photosensitive layer having a charge transport layer being an outermost layer or a single-layer photosensitive layer. The amount of silica particles contained in the photosensitive layer is at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of a binder resin contained in the photosensitive layer.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: February 21, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Kensuke Okawa, Akihiko Ogata, Takahiro Oki
  • Patent number: 9448496
    Abstract: An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer located on the charge generating layer. The charge transport layer contains a pigment that is absorptive with respect to a wavelength of exposed light. The pigment is a metal phthalocyanine pigment represented by General Formula (I) or a metal-free phthalocyanine pigment represented by General Formula (II), where X represents a sulfur atom or an oxygen atom. R1 represents an aryl group or an alkyl group. R2-R4 each represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a phenoxy group, an alkylthio group, a phenylthio group, or a dialkylamino group. M represents a metal atom. Y represents non-substitution or an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an oxygen atom, or a hydroxyl group.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: September 20, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Jun Azuma, Keiji Maruo, Kensuke Okawa, Akihiko Ogata