Patents by Inventor Tatsuya Yamaai
Tatsuya Yamaai 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).
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Publication number: 20240118634Abstract: The electrophotographic photosensitive member includes a support and a photosensitive layer on the support, in which a surface layer of the electrophotographic photosensitive member contains a particle, the surface layer has a particle partially exposed from the surface layer among the particle contained in the surface layer, the particle has a volume average particle diameter of 50.0 nm or more and 350.0 nm or less; in a cross-section of the surface layer, the number of the particle partially exposed from the surface layer is 80% by number or more based on a total number of the particle contained in the surface layer; and a total volume of an exposed portion of the particle partially exposed from the surface layer is 30% by volume or more and 80% by volume or less based on an entire volume of the particle contained in the surface layer.Type: ApplicationFiled: November 30, 2023Publication date: April 11, 2024Inventors: SHUNTARO WATANABE, TOMOHITO ISHIDA, NOBUHIRO NAKAMURA, HIROYUKI WATANABE, TATSUYA YAMAAI, MASATADA HIROTA
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Publication number: 20240118635Abstract: Provided is an electrophotographic photosensitive member that achieves satisfactory transferability. An electrophotographic photosensitive member including a charge generating layer, a charge transporting layer, and a protection layer laminated on a support in the stated order, wherein the protection layer contains a binder resin and particles, and wherein when an average thickness of the protection layer in a site free of the particles is represented by T and a volume-average particle diameter of the particles is represented by Dm in a cross-section of the protection layer, the following formula (a) is satisfied.Type: ApplicationFiled: November 30, 2023Publication date: April 11, 2024Inventors: TOMOHITO ISHIDA, SHUNTARO WATANABE, NOBUHIRO NAKAMURA, TATSUYA YAMAAI, HIROYUKI WATANABE, MASATADA HIROTA
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Patent number: 11947275Abstract: Provided is an electrophotographic apparatus including: an electrophotographic photosensitive member; a voltage application unit configured to cause discharge from an electroconductive member to the electrophotographic photosensitive member; a charge transfer amount detection unit configured to detect a charge transfer amount per unit time resulting from the discharge from the electroconductive member to the electrophotographic photosensitive member; and a charging potential control unit, wherein V1 and V2 defined by specific procedures for the electrophotographic photosensitive member satisfy a relationship represented by the following expression (E-4): 100V1<V2?V1 (E-4), and wherein the charging potential control unit is configured to control the charging potential of the electrophotographic photosensitive member at the time of image formation.Type: GrantFiled: February 14, 2023Date of Patent: April 2, 2024Assignee: CANON KABUSHIKI KAISHAInventors: Shuhei Iwasaki, Kaname Watariguchi, Akihiro Maruyama, Kenichi Kaku, Michiyo Sekiya, Kohei Makisumi, Tatsuya Yamaai, Hideharu Shimozawa, Naoki Fukushima
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Patent number: 11782353Abstract: A method for producing an electrophotographic photosensitive member including: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer having an amount of residual solvent of a first solvent in the photosensitive layer of 0.05% to 2.50% and an amount of residual solvent of a second solvent in the photosensitive layer of 0.50% to 2.50%, and the step of forming the protective layer includes step (A) of forming a cured film and step (B) of forming the protective layer having wrinkle shapes, wherein, in step (A), the irradiated coating film is heated at a heating temperature lower than a boiling point of the first solvent and in step (B), the cured film is heated at a heating temperature higher than a boiling point of the first solvent.Type: GrantFiled: April 13, 2021Date of Patent: October 10, 2023Assignee: CANON KABUSHIKI KAISHAInventors: Nobuhiro Nakamura, Tomohito Ishida, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
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Publication number: 20230288836Abstract: Provided is an electrophotographic apparatus including: an electrophotographic photosensitive member; a voltage application unit configured to cause discharge from an electroconductive member to the electrophotographic photosensitive member; a charge transfer amount detection unit configured to detect a charge transfer amount per unit time resulting from the discharge from the electroconductive member to the electrophotographic photosensitive member; and a charging potential control unit, wherein V1 and V2 defined by specific procedures for the electrophotographic photosensitive member satisfy a relationship represented by the following expression (E-4): 100V1<V2?V1 (E-4), and wherein the charging potential control unit is configured to control the charging potential of the electrophotographic photosensitive member at the time of image formation.Type: ApplicationFiled: February 14, 2023Publication date: September 14, 2023Inventors: SHUHEI IWASAKI, KANAME WATARIGUCHI, AKIHIRO MARUYAMA, KENICHI KAKU, MICHIYO SEKIYA, KOHEI MAKISUMI, TATSUYA YAMAAI, HIDEHARU SHIMOZAWA, NAOKI FUKUSHIMA
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Publication number: 20230068976Abstract: The present disclosure provides a photoelectric conversion element including a first electrode 3, a second electrode 7, a photoelectric conversion layer 5 between the first electrode 3 and the second electrode 7, and a reflection layer 6 between one of the first electrode 3 and the second electrode 7 and the photoelectric conversion layer 5. The wavelength at which the reflectance of the reflection layer 6 is maximum in the visible region is within the range of wavelengths in which the optical absorption coefficient of the photoelectric conversion layer 5 is ? or more of the maximum optical absorption coefficient in the visible region.Type: ApplicationFiled: September 15, 2022Publication date: March 2, 2023Inventors: Hiroyuki Watanabe, Akihiro Maruyama, Tatsuya Yamaai, Kenichi Kaku, Shuntaro Watanabe, Jumpei Kuno, Kazunori Noguchi, Takashi Anezaki, Nobuhiro Nakamura, Kohei Makisumi
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Publication number: 20230059773Abstract: An electrophotographic photosensitive member includes: a support; an undercoat layer; a charge generation layer; and a charge transport layer, wherein the undercoat layer contains a polyamide resin and a titanium oxide fine particle, and on the surface of the undercoat layer, an arithmetic mean roughness Ra and an average length Rsm of a roughness curve element both according to JIS B0601:2001 satisfy Ra?50 nm and 0.1?Ra/Rsm?0.5; and the charge generation layer contains a hydroxygallium phthalocyanine pigment, wherein the hydroxygallium phthalocyanine pigment includes crystal particles having a crystal form exhibiting peaks at 7.4°±0.3° and 28.2°±0.3° at Bragg angles 2? in a spectrum of X-ray diffraction using a CuK?, ray; and in a size distribution of the crystal particles, which is measured using small-angle X-ray scattering, a peak exists in a range of 20 to 50 nm, and the peak has a half-value width of 50 nm or smaller.Type: ApplicationFiled: July 25, 2022Publication date: February 23, 2023Inventors: Tatsuya Yamaai, Kaname Watariguchi, Kenichi Kaku, Shuhei Iwasaki, Akihiro Maruyama
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Publication number: 20230059041Abstract: Provided is an electrophotographic apparatus which uses a light emitting diode array as an exposure unit and exposes a photosensitive member to a quantity of light from the LED array whose average light quantity satisfies 0.8×Emin or more and 1.1×Emin or less on condition that a normalized radius of curvature R of a normalized graph derived from the E-V curve of the photosensitive member has a minimum value of 0.24 or less, and a light quantity at the minimum value of the normalized radius of curvature R is Emin [?J/cm2]. This electrophotographic apparatus prevents both the occurrence of image unevenness due to light quantity variation among the elements of the LED array and the generation of ghost images due to a rest potential.Type: ApplicationFiled: July 29, 2022Publication date: February 23, 2023Inventors: Kenichi Kaku, Akihiro Maruyama, Shuhei Iwasaki, Tatsuya Yamaai, Kaname Watariguchi, Michiyo Sekiya, Kohei Makisumi, Hideharu Shimozawa
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Publication number: 20230058278Abstract: The electrophotographic apparatus includes: an electrophotographic photosensitive member; a charging unit; an image-exposing unit; a charge transfer amount-sensing unit for sensing the amount of charge transferred to the electrophotographic photosensitive member; and an exposed portion potential-controlling unit for controlling the potential of each of the exposed portions of the electrophotographic photosensitive member based on a sensing result, which is obtained by charging the electrophotographic photosensitive member with the charging unit, performing image exposure with the image-exposing unit in at least one light amount weaker than a light amount in which the normalized radius of curvature R of the electrophotographic photosensitive member represented by the following equation (E1), the normalized radius of curvature being obtained by a method of measuring an EV curve, shows a minimum, and in at least two light amounts stronger than the light amount in which the normalized radius of curvature shows thType: ApplicationFiled: July 27, 2022Publication date: February 23, 2023Inventors: Akihiro Maruyama, Kenichi Kaku, Shuhei Iwasaki, Kohei Makisumi, Michiyo Sekiya, Kaname Watariguchi, Hideharu Shimozawa, Tatsuya Yamaai, Takanori Mitani, Satoshi Nishida
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Patent number: 11392074Abstract: Provided is an electrophotographic photosensitive drum that achieves both of a reduction in torque of the electrophotographic photosensitive drum at the time of its cleaning and an improvement in image transferability. The electrophotographic photosensitive drum includes: a support; and a photosensitive layer arranged on the support, the electrophotographic photosensitive drum having arranged on an outer surface thereof at least two structure groups having different appearance periods, wherein when, out of the two structure groups, a group including structures having a smaller appearance period is defined as a first structure group, and a group including structures having a larger appearance period is defined as a second structure group, a height of the first structure group is lower than a height of the second structure group.Type: GrantFiled: April 13, 2021Date of Patent: July 19, 2022Assignee: CANON KABUSHIKI KAISHAInventors: Tomohito Ishida, Nobuhiro Nakamura, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
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Publication number: 20210325814Abstract: Provided is an electrophotographic photosensitive drum that achieves both of a reduction in torque of the electrophotographic photosensitive drum at the time of its cleaning and an improvement in image transferability. The electrophotographic photosensitive drum includes: a support; and a photosensitive layer arranged on the support, the electrophotographic photosensitive drum having arranged on an outer surface thereof at least two structure groups having different appearance periods, wherein when, out of the two structure groups, a group including structures having a smaller appearance period is defined as a first structure group, and a group including structures having a larger appearance period is defined as a second structure group, a height of the first structure group is lower than a height of the second structure group.Type: ApplicationFiled: April 13, 2021Publication date: October 21, 2021Inventors: Tomohito Ishida, Nobuhiro Nakamura, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka lshiduka, Yota Ito, Takeshi Murakami
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Publication number: 20210325794Abstract: There is provided an electrophotographic photosensitive member having drum shape, the electrophotographic photosensitive member including a support and a photosensitive layer, wherein an outer surface of the electrophotographic photosensitive member has wrinkles, and when an observation region having square form with one side of 100 ?m is placed at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a first reference line L1, and 3,599 reference lines obtained by rotating the first reference line L1 at every 0.1° around the central point are defined as L2 to L3,600, respectively, each of L1 to L3,600 intersects with convex portions of the wrinkles at a plurality of locations and has at least two different intersection angles selected from the plurality of locations.Type: ApplicationFiled: April 14, 2021Publication date: October 21, 2021Inventors: Shuhei Iwasaki, Tomohito Ishida, Nobuhiro Nakamura, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka Ishiduka, Yota Ito, Takeshi Murakami
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Publication number: 20210325793Abstract: A method for producing an electrophotographic photosensitive member including: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer having an amount of residual solvent of a first solvent in the photosensitive layer of 0.05% to 2.50% and an amount of residual solvent of a second solvent in the photosensitive layer of 0.50% to 2.50%, and the step of forming the protective layer includes step (A) of forming a cured film and step (B) of forming the protective layer having wrinkle shapes, wherein, in step (A), the irradiated coating film is heated at a heating temperature lower than a boiling point of the first solvent and in step (B), the cured film is heated at a heating temperature higher than a boiling point of the first solvent.Type: ApplicationFiled: April 13, 2021Publication date: October 21, 2021Inventors: Nobuhiro Nakamura, Tomohito Ishida, Shuhei Iwasaki, Hiroyuki Watanabe, Tatsuya Yamaai, Yuka lshiduka, Yota Ito, Takeshi Murakami
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Patent number: 10983449Abstract: A method for manufacturing an electrophotographic photoconductor including a charge generating layer and a charge transport layer in this order on a cylindrical electrically-conductive support including the steps of: (i) immersing the support in a charge generating layer coating liquid, (ii) pulling the support out of the coating liquid, (iii) heat drying the support coated with the coating liquid to form the charge generating layer, (iv) cooling the charge generating layer, and (v) immersing the support on which the charge generating layer has been formed in a charge transport layer coating liquid while retaining gas inside of the support. The charge transport layer coating liquid contains a solvent having a boiling point of 34° C. or more and 85° C. or less, and the step (v) satisfies two specific conditions.Type: GrantFiled: March 24, 2020Date of Patent: April 20, 2021Assignee: Canon Kabushiki KaishaInventors: Akihiro Maruyama, Kazuko Araki, Daisuke Miura, Tatsuya Yamaai, Hiroto Hirayama, Shinobu Iijima, Daisuke Kawaguchi, Takahiro Nagase, Takahisa Taniguchi, Shintarou Goto, Taneyuki Kinoshita
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Publication number: 20200310262Abstract: A method for manufacturing an electrophotographic photoconductor including a charge generating layer and a charge transport layer in this order on a cylindrical electrically-conductive support including the steps of: (i) immersing the support in a charge generating layer coating liquid, (ii) pulling the support out of the coating liquid, (iii) heat drying the support coated with the coating liquid to form the charge generating layer, (iv) cooling the charge generating layer, and (v) immersing the support on which the charge generating layer has been formed in a charge transport layer coating liquid while retaining gas inside of the support. The charge transport layer coating liquid contains a solvent having a boiling point of 34° C. or more and 85° C. or less, and the step (v) satisfies two specific conditions.Type: ApplicationFiled: March 24, 2020Publication date: October 1, 2020Inventors: Akihiro Maruyama, Kazuko Araki, Daisuke Miura, Tatsuya Yamaai, Hiroto Hirayama, Shinobu Iijima, Daisuke Kawaguchi, Takahiro Nagase, Takahisa Taniguchi, Shintarou Goto, Taneyuki Kinoshita
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Patent number: 10663913Abstract: Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mm2 or less.Type: GrantFiled: November 21, 2018Date of Patent: May 26, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Tatsuya Yamaai, Kazunori Noguchi, Shuhei Iwasaki, Akira Sakakibara, Daisuke Miura, Harunobu Ogaki, Takumi Furukawa, Yuya Tomomizu
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Patent number: 10545453Abstract: Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm2 or more and 20 N/mm2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.Type: GrantFiled: November 20, 2018Date of Patent: January 28, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Shuhei Iwasaki, Kazunori Noguchi, Harunobu Ogaki, Tatsuya Yamaai, Daisuke Miura, Akira Sakakibara, Takumi Furukawa, Yuya Tomomizu
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Patent number: 10452021Abstract: A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.Type: GrantFiled: November 21, 2018Date of Patent: October 22, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Daisuke Miura, Shuhei Iwasaki, Akira Sakakibara, Tatsuya Yamaai, Kazunori Noguchi, Harunobu Ogaki, Kazunari Hagiwara, Yuji Kawaguchi
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Patent number: 10416581Abstract: An electrophotographic photosensitive member with suppressed potential variation even in the case that a protective layer including a cured material of a composition having a polymerizable functional group is used is provided. An electrophotographic photosensitive member including a support, a charge generation layer, a charge transport layer containing a charge transporting material, and a protective layer, in the order presented, wherein the charge transport layer contains a polycarbonate resin having a structure selected from a group A and a structure selected from a group B, and the protective layer includes a cured material of a composition containing a compound having at least a functional group selected from chain-polymerizable functional groups and sequential polymerizable functional groups.Type: GrantFiled: August 3, 2017Date of Patent: September 17, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Yota Ito, Tsutomu Nishida, Shoma Hinata, Tatsuya Yamaai, Akira Sakakibara, Daisuke Miura
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Publication number: 20190163120Abstract: A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.Type: ApplicationFiled: November 21, 2018Publication date: May 30, 2019Inventors: Daisuke Miura, Shuhei Iwasaki, Akira Sakakibara, Tatsuya Yamaai, Kazunori Noguchi, Harunobu Ogaki, Kazunari Hagiwara, Yuji Kawaguchi