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: 10871723Abstract: 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: GrantFiled: December 28, 2017Date of Patent: December 22, 2020Assignee: KYOCERA Document Solutions Inc.Inventors: Kensuke Okawa, Seiki Hasunuma, Jun Azuma
-
Patent number: 10761439Abstract: 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: GrantFiled: August 4, 2017Date of Patent: September 1, 2020Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Kensuke Okawa, Seiki Hasunuma, Tomofumi Shimizu
-
Publication number: 20200233321Abstract: 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: ApplicationFiled: January 17, 2020Publication date: July 23, 2020Applicant: KYOCERA Document Solutions Inc.Inventors: Kazutaka SUGIMOTO, Kensuke OKAWA, Jun AZUMA
-
Publication number: 20200026207Abstract: 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: ApplicationFiled: December 28, 2017Publication date: January 23, 2020Applicant: KYOCERA Document Solutions Inc.Inventors: Kensuke OKAWA, Seiki HASUNUMA, Jun AZUMA
-
Patent number: 10379451Abstract: 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: GrantFiled: February 26, 2018Date of Patent: August 13, 2019Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Kensuke Okawa, Akihiko Ogata, Kenji Kitaguchi, Tomofumi Shimizu
-
Patent number: 10273331Abstract: 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: GrantFiled: November 28, 2017Date of Patent: April 30, 2019Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Kenji Kitaguchi, Kensuke Okawa, Seiki Hasunuma, Tomofumi Shimizu
-
Publication number: 20180246424Abstract: 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: ApplicationFiled: February 26, 2018Publication date: August 30, 2018Applicant: KYOCERA Document Solutions Inc.Inventors: Jun AZUMA, Kensuke OKAWA, Akihiko OGATA, Kenji KITAGUCHI, Tomofumi SHIMIZU
-
Patent number: 10031431Abstract: 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: GrantFiled: April 20, 2017Date of Patent: July 24, 2018Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Takahiro Oki, Kensuke Okawa, Akihiko Ogata
-
Publication number: 20180148538Abstract: 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: ApplicationFiled: November 28, 2017Publication date: May 31, 2018Applicant: KYOCERA Document Solutions Inc.Inventors: Jun AZUMA, Kenji KITAGUCHI, Kensuke OKAWA, Seiki HASUNUMA, Tomofumi SHIMIZU
-
Patent number: 9964869Abstract: 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: GrantFiled: November 8, 2016Date of Patent: May 8, 2018Assignee: KYOCERA Document Solutions Inc.Inventors: Kensuke Okawa, Hideki Okada, Jun Azuma, Fumio Sugai, Kensuke Kojima
-
Patent number: 9939744Abstract: 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: GrantFiled: September 1, 2016Date of Patent: April 10, 2018Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Kensuke Okawa, Junichiro Otsubo, Akihiko Ogata
-
Patent number: 9933712Abstract: 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: GrantFiled: August 25, 2016Date of Patent: April 3, 2018Assignee: KYOCERA Document Solutions Inc.Inventors: Akihiko Ogata, Hideki Okada, Jun Azuma, Kensuke Okawa
-
Publication number: 20180046099Abstract: 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: ApplicationFiled: August 4, 2017Publication date: February 15, 2018Applicant: KYOCERA Document Solutions Inc.Inventors: Jun AZUMA, Kensuke OKAWA, Seiki HASUNUMA, Tomofumi SHIMIZU
-
Publication number: 20170307989Abstract: 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: ApplicationFiled: April 20, 2017Publication date: October 26, 2017Applicant: KYOCERA Document Solutions Inc.Inventors: Jun AZUMA, Takahiro OKI, Kensuke OKAWA, Akihiko OGATA
-
Publication number: 20170131647Abstract: 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: ApplicationFiled: November 8, 2016Publication date: May 11, 2017Applicant: KYOCERA Document Solutions Inc.Inventors: Kensuke OKAWA, Hideki OKADA, Jun AZUMA, Fumio SUGAI, Kensuke KOJIMA
-
Patent number: 9625839Abstract: 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: GrantFiled: December 28, 2011Date of Patent: April 18, 2017Assignee: KYOCERA Document Solutions Inc.Inventors: Makoto Shishido, Kensuke Okawa
-
Publication number: 20170068178Abstract: 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: ApplicationFiled: September 1, 2016Publication date: March 9, 2017Applicant: KYOCERA Document Solutions Inc.Inventors: Jun AZUMA, Kensuke OKAWA, Junichiro OTSUBO, Akihiko OGATA
-
Publication number: 20170060006Abstract: 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: ApplicationFiled: August 25, 2016Publication date: March 2, 2017Applicant: KYOCERA Document Solutions Inc.Inventors: Akihiko OGATA, Hideki OKADA, Jun AZUMA, Kensuke OKAWA
-
Patent number: 9575423Abstract: 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: GrantFiled: March 6, 2015Date of Patent: February 21, 2017Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Kensuke Okawa, Akihiko Ogata, Takahiro Oki
-
Patent number: 9448496Abstract: 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: GrantFiled: May 22, 2015Date of Patent: September 20, 2016Assignee: KYOCERA Document Solutions Inc.Inventors: Jun Azuma, Keiji Maruo, Kensuke Okawa, Akihiko Ogata