Patents by Inventor Kohei Okayasu
Kohei Okayasu 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: 20240345529Abstract: An image forming apparatus includes an image forming unit including an image bearing member, an intermediate transfer member, and a transfer roller, a conveyance rotary member pair, a fixing unit, a first conveyance path, a second conveyance path, a reverse conveyance unit, and a control unit. The control unit is configured to perform a conveyance operation of conveying the sheet, the conveyance operation including (i) a first conveyance processing of conveying the sheet toward the reverse conveyance, (ii) a second conveyance processing of conveying the sheet toward the second conveyance path by the reverse conveyance unit, and (iii) a third conveyance processing of transferring the toner image to the sheet at the transfer nip portion. A surface, of the sheet, that faces the pressure roller in the first conveyance processing is configured to face the intermediate transfer member in the third conveyance processing.Type: ApplicationFiled: March 29, 2024Publication date: October 17, 2024Inventors: KOHEI OKAYASU, TAKAO KUME
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Publication number: 20240302768Abstract: An image-forming apparatus includes first and second photosensitive drums, first and second image-forming portion including first and second development rollers configured to bear developers composed of first and second toner particles and organosilicon protrusions formed on surfaces of the first and second toner particles, an intermediate transfer member to which a developer image is to be transferred in first and second contact portions in contact with the first and second photosensitive drums, and a transfer member configured to transfer the developer image to a recording material in a transfer portion. The first contact portion is formed downstream of the transfer portion and upstream of the second contact portion in a movement direction of the surface of the intermediate transfer member. A protrusion formed on the second developer has a lower height than a protrusion formed on the first developer.Type: ApplicationFiled: May 21, 2024Publication date: September 12, 2024Inventors: TAKANORI MITANI, TAKAO KUME, SATOSHI NISHIDA, ISAMU TAKEDA, KOHEI OKAYASU
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Publication number: 20240255875Abstract: A fixing apparatus includes first and second rotating members, a heater having a heating element and a substrate, and first and second contact members. A direction of a longer side on a surface of the substrate where the heating element is disposed is a longitudinal direction. A direction intersecting the longitudinal direction is a widthwise direction. The first contact member is disposed in a region outside a region where a maximum size recording material conveyed to a nip portion passes through the nip portion on one end side in the longitudinal direction on an outer circumferential surface of the first rotating member, and the second contact member is disposed in the region outside the region where the maximum size recording material conveyed to the nip portion passes through the nip portion on an other end side in the longitudinal direction on an outer circumferential surface of the second rotating member.Type: ApplicationFiled: December 18, 2023Publication date: August 1, 2024Inventors: TAKAO KUME, AKIMICHI SUZUKI, SATOSHI NISHIDA, KOHEI OKAYASU, TAKANORI MITANI
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Patent number: 12019380Abstract: An image-forming apparatus includes first and second photosensitive drums, first and second image-forming portion including first and second development rollers configured to bear developers composed of first and second toner particles and organosilicon protrusions formed on surfaces of the first and second toner particles, an intermediate transfer member to which a developer image is to be transferred in first and second contact portions in contact with the first and second photosensitive drums, and a transfer member configured to transfer the developer image to a recording material in a transfer portion. The first contact portion is formed downstream of the transfer portion and upstream of the second contact portion in a movement direction of the surface of the intermediate transfer member. A protrusion formed on the second developer has a lower height than a protrusion formed on the first developer.Type: GrantFiled: January 19, 2023Date of Patent: June 25, 2024Assignee: CANON KABUSHIKI KAISHAInventors: Takanori Mitani, Takao Kume, Satoshi Nishida, Isamu Takeda, Kohei Okayasu
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Publication number: 20240111231Abstract: An image forming apparatus includes: a first and second rotation bodies; a heater disposed in the first rotation body; and a frame body supporting the first and second rotation bodies. A second length is smaller than a first length in a rotational axis direction of the second rotation body, the first length and the second length being a length of a rotation shaft of the second rotation body exposed on a one-end side and an other-end side of the second rotation body, and a second value is larger than a first value, the first value and the second value being a total area of openings disposed in a first region and a second region of the frame body respectively corresponding to the one-end side and the other-end side of the frame body with respect to a center of the frame body.Type: ApplicationFiled: September 22, 2023Publication date: April 4, 2024Inventors: SATOSHI NISHIDA, KOHEI OKAYASU, TAKAO KUME
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Publication number: 20230236526Abstract: An image-forming apparatus includes first and second photosensitive drums, first and second image-forming portion including first and second development rollers configured to bear developers composed of first and second toner particles and organosilicon protrusions formed on surfaces of the first and second toner particles, an intermediate transfer member to which a developer image is to be transferred in first and second contact portions in contact with the first and second photosensitive drums, and a transfer member configured to transfer the developer image to a recording material in a transfer portion. The first contact portion is formed downstream of the transfer portion and upstream of the second contact portion in a movement direction of the surface of the intermediate transfer member. A protrusion formed on the second developer has a lower height than a protrusion formed on the first developer.Type: ApplicationFiled: January 19, 2023Publication date: July 27, 2023Inventors: TAKANORI MITANI, TAKAO KUME, SATOSHI NISHIDA, ISAMU TAKEDA, KOHEI OKAYASU
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Patent number: 11644766Abstract: A region of an image bearing member that comes into contact with a recording material at a nip in a state in which the recording material is held by the nip is a first region, and a region of the image bearing member that does not come into contact with the recording material at the nip in a state in which the recording material is not held by the nip is a second region. A controller controls to apply a first developing voltage to a developer bearing member when the first region in which a first surface potential has been formed faces a developer bearing member and apply a second developing voltage lower than an absolute value of the first developing voltage to the developer bearing member when the second region in which a second surface potential has been formed faces the developer bearing member.Type: GrantFiled: May 27, 2021Date of Patent: May 9, 2023Assignee: Canon Kabushiki KaishaInventor: Kohei Okayasu
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Patent number: 11237504Abstract: An image forming apparatus including: an obtaining portion that divides image data into a plurality of regions in a sub scanning direction, and obtains, for each of the plurality of regions in the sub scanning direction, a first value relating to pixels having density at at least a prescribed value in a first width and a second value relating to pixels having density at at least the prescribed value in a second width, which is greater than the first width; a determining portion that determines, for each of the plurality of regions, a target temperature for maintaining a temperature of a heating member on the basis of the first and second values; and a control portion that controls power supplied to the heating member so that the temperature of the heating member is maintained at the target temperature.Type: GrantFiled: August 26, 2020Date of Patent: February 1, 2022Assignee: Canon Kabushiki KaishaInventors: Shingo Ito, Kohei Okayasu
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Publication number: 20210373453Abstract: A region of an image bearing member that comes into contact with a recording material at a nip in a state in which the recording material is held by the nip is a first region, and a region of the image bearing member that does not come into contact with the recording material at the nip in a state in which the recording material is not held by the nip is a second region. A controller controls to apply a first developing voltage to a developer bearing member when the first region in which a first surface potential has been formed faces a developer bearing member and apply a second developing voltage smaller than an absolute value of the first developing voltage to the developer bearing member when the second region in which a second surface potential has been formed faces the developer bearing member.Type: ApplicationFiled: May 27, 2021Publication date: December 2, 2021Inventor: Kohei Okayasu
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Patent number: 11036159Abstract: An image forming apparatus includes a photoconductor including a charge generation layer; a charging member to charge a surface of the photoconductor; and an exposure unit to expose the surface of the photoconductor to form a toner image on the surface of the photoconductor charged. The exposure unit exposes the surface of the photoconductor by scanning a laser beam in a main scanning direction at a non-constant scan rate, and exposure amount per unit length of the surface of the photoconductor in the main scanning direction is larger in a first region than in a second region. The first region is in the surface of the photoconductor exposed at a first scan rate. The second region is in the surface of the photoconductor exposed at a second scan rate higher than the first scan rate. The charge generation layer is thinner in the first region than in the second region.Type: GrantFiled: November 18, 2019Date of Patent: June 15, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Shingo Ito, Masashi Tanaka, Kohei Okayasu, Kenichi Iida
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Patent number: 10948857Abstract: An image forming apparatus includes an image forming unit configured to form an image based on image data, a fixing unit configured to fix the image formed by the image forming unit on a recording material, a conversion unit configured to convert image data into conversion data including a plurality of areas having a first resolution in a main scanning direction perpendicular to a conveyance direction of the recording material, and a second resolution higher than the first resolution in a sub-scanning direction, which is the conveyance direction of the recording material, an analysis unit configured to analyze values related to the areas of the plurality of areas of the conversion data obtained by the conversion unit, and a temperature control unit configured to control a fixing temperature of the fixing unit according to a result of the analysis performed by the analysis unit.Type: GrantFiled: April 14, 2020Date of Patent: March 16, 2021Assignee: Canon Kabushiki KaishaInventors: Kohei Okayasu, Masashi Tanaka, Shingo Ito
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Publication number: 20210063924Abstract: An image forming apparatus including: an obtaining portion that divides image data into a plurality of regions in a sub scanning direction, and obtains, for each of the plurality of regions in the sub scanning direction, a first value relating to pixels having density at at least a prescribed value in a first width and a second value relating to pixels having density at at least the prescribed value in a second width, which is greater than the first width; a determining portion that determines, for each of the plurality of regions, a target temperature for maintaining a temperature of a heating member on the basis of the first and second values; and a control portion that controls power supplied to the heating member so that the temperature of the heating member is maintained at the target temperature.Type: ApplicationFiled: August 26, 2020Publication date: March 4, 2021Inventors: Shingo Ito, Kohei Okayasu
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Publication number: 20200241454Abstract: An image forming apparatus includes an image forming unit configured to form an image based on image data, a fixing unit configured to fix the image formed by the image forming unit on a recording material, a conversion unit configured to convert image data into conversion data including a plurality of areas having a first resolution in a main scanning direction perpendicular to a conveyance direction of the recording material, and a second resolution higher than the first resolution in a sub-scanning direction, which is the conveyance direction of the recording material, an analysis unit configured to analyze values related to the areas of the plurality of areas of the conversion data obtained by the conversion unit, and a temperature control unit configured to control a fixing temperature of the fixing unit according to a result of the analysis performed by the analysis unit.Type: ApplicationFiled: April 14, 2020Publication date: July 30, 2020Inventors: Kohei Okayasu, Masashi Tanaka, Shingo Ito
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Publication number: 20200174394Abstract: An image forming apparatus includes a photoconductor including a charge generation layer; a charging member to charge a surface of the photoconductor; and an exposure unit to expose the surface of the photoconductor to form a toner image on the surface of the photoconductor charged. The exposure unit exposes the surface of the photoconductor by scanning a laser beam in a main scanning direction at a non-constant scan rate, and exposure amount per unit length of the surface of the photoconductor in the main scanning direction is larger in a first region than in a second region. The first region is in the surface of the photoconductor exposed at a first scan rate. The second region is in the surface of the photoconductor exposed at a second scan rate higher than the first scan rate. The charge generation layer is thinner in the first region than in the second region.Type: ApplicationFiled: November 18, 2019Publication date: June 4, 2020Inventors: Shingo Ito, Masashi Tanaka, Kohei Okayasu, Kenichi Iida
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Patent number: 10656576Abstract: An image forming apparatus includes an image forming unit configured to form an image based on image data, a fixing unit configured to fix the image formed by the image forming unit on a recording material, a conversion unit configured to convert image data into conversion data including a plurality of areas having a first resolution in a main scanning direction perpendicular to a conveyance direction of the recording material, and a second resolution higher than the first resolution in a sub-scanning direction, which is the conveyance direction of the recording material, an analysis unit configured to analyze values related to the areas of the plurality of areas of the conversion data obtained by the conversion unit, and a temperature control unit configured to control a fixing temperature of the fixing unit according to a result of the analysis performed by the analysis unit.Type: GrantFiled: April 18, 2019Date of Patent: May 19, 2020Assignee: Canon Kabushiki KaishaInventors: Kohei Okayasu, Masashi Tanaka, Shingo Ito
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Publication number: 20190332042Abstract: An image forming apparatus includes an image forming unit configured to form an image based on image data, a fixing unit configured to fix the image formed by the image forming unit on a recording material, a conversion unit configured to convert image data into conversion data including a plurality of areas having a first resolution in a main scanning direction perpendicular to a conveyance direction of the recording material, and a second resolution higher than the first resolution in a sub-scanning direction, which is the conveyance direction of the recording material, an analysis unit configured to analyze values related to the areas of the plurality of areas of the conversion data obtained by the conversion unit, and a temperature control unit configured to control a fixing temperature of the fixing unit according to a result of the analysis performed by the analysis unit.Type: ApplicationFiled: April 18, 2019Publication date: October 31, 2019Inventors: Kohei Okayasu, Masashi Tanaka, Shingo Ito
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Patent number: 10444673Abstract: There is provided an image forming apparatus including a configuration in which a voltage of a polarity opposite to a toner charging polarity is applied. In the image forming apparatus, a guide region of a pre-transfer guide is located on a photosensitive drum side with respect to a common tangent line of a photosensitive drum and a development roller to reduce contamination of the pre-transfer guide and prevent contamination of recording materials.Type: GrantFiled: November 14, 2018Date of Patent: October 15, 2019Assignee: Canon Kabushiki KaishaInventors: Kenji Shindo, Shinsuke Kobayashi, Takaaki Akamatsu, Kohei Okayasu, Takehiko Suzuki
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Patent number: 10386755Abstract: An image forming apparatus includes a discharging device for discharging the drum at a discharging portion opposing the surface of the drum; and a control unit for executing, during non-image formation, a cleaning operation for transferring the toner deposited on the transfer member onto the drum by applying a voltage from transfer voltage source to the transfer member. The control unit does not effect discharge by the discharging device for at least a region of the drum where a transfer voltage for transferring a normal-polarity toner of the toner deposited on the transfer member onto the drum is applied to the transfer member in the cleaning operation, and then passes the region of the drum through the charging portion in a state in which a voltage larger than a surface potential of the drum in a normal polarity side is applied to the charging member.Type: GrantFiled: June 27, 2018Date of Patent: August 20, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Shinsuke Kobayashi, Takaaki Akamatsu, Kenji Shindo, Kohei Okayasu, Hiroki Sasame
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Publication number: 20190079434Abstract: There is provided an image forming apparatus including a configuration in which a voltage of a polarity opposite to a toner charging polarity is applied. In the image forming apparatus, a guide region of a pre-transfer guide is located on a photosensitive drum side with respect to a common tangent line of a photosensitive drum and a development roller to reduce contamination of the pre-transfer guide and prevent contamination of recording materials.Type: ApplicationFiled: November 14, 2018Publication date: March 14, 2019Inventors: Kenji Shindo, Shinsuke Kobayashi, Takaaki Akamatsu, Kohei Okayasu, Takehiko Suzuki
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Patent number: 10222718Abstract: In a configuration in which a voltage of polarity opposite to charging polarity of toner is applied to a conveyance guide, controlling deposition of toner on the conveyance guide has been difficult. When performing duplex image formation, a potential difference between a surface potential of a photoconductive drum charged by a charging roller and a potential of the conveyance guide is smaller during printing on the second surface than during printing on the first surface.Type: GrantFiled: May 25, 2017Date of Patent: March 5, 2019Assignee: Canon Kabushiki KaishaInventors: Kohei Okayasu, Masashi Tanaka, Sho Taguchi