Patents by Inventor Kohei Wakatsu
Kohei Wakatsu 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: 20230400803Abstract: The heater including a substrate, a first heat generation member, a second heat generation member having a length substantially a same in a longitudinal direction as a length of the first heat generation member, a third heat generation member having a length shorter than lengths of the first heat generation member and the second heat generation member in the longitudinal direction, and a fourth heat generation member having a length shorter than length of the third heat generation member in the longitudinal direction, wherein the first heat generation member, the second heat generation member, the third heat generation member and the fourth heat generation member are arranged on the substrate.Type: ApplicationFiled: August 28, 2023Publication date: December 14, 2023Inventors: Kazuhiro Doda, Ken Nakagawa, Tsuguhiro Yoshida, Yutaka Sato, Kohei Wakatsu
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Patent number: 11835909Abstract: An image forming apparatus includes a first rotating member, a heater, a second rotating member, a detecting unit, a switching unit, a controlling unit, and a power source device. In a first period, a resultant current of first and third currents is supplied to a first heat generating element, and the resultant current in a unit cycle of a first period is a current at which a first current supplying timing and timings of a maximum and a minimum of the third current do not overlap with each other. In a second period, a resultant current of second and third currents is supplied to a second heat generating element, and the resultant current in a unit cycle of the second period is a current at which a second current supplying timing and the timings of the maximum and the minimum of the third current overlap with each other.Type: GrantFiled: May 10, 2022Date of Patent: December 5, 2023Assignee: Canon Kabushiki KaishaInventors: Nozomu Nakajima, Atsushi Nakamoto, Kohei Wakatsu
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Patent number: 11835896Abstract: A fixing device includes a substrate, a first heat generator, a second heat generator with a length in a longitudinal direction of the substrate equal to a length of the first heat generator; and a third heat generator with a length shorter than the lengths of the first and second heat generators, a soaking member with a positioning portion in the longitudinal direction. In a short side direction of the substrate, the first heat generator is arranged at one end side, the second heat generator is arranged at the other end side, and the third heat generator is arranged between the first and second heat generators. The soaking member is arranged between the heater and a holder in a thickness direction. As seen in the short side direction, the positioning portion is positioned outside of an area corresponding to the third heat generator and inside of an area corresponding to the first heat generator.Type: GrantFiled: August 5, 2022Date of Patent: December 5, 2023Assignee: Canon Kabushiki KaishaInventors: Tsuguhiro Yoshida, Kohei Wakatsu
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Publication number: 20230314990Abstract: A fixing unit includes a tubular film, a pressure roller, a heater including a first heating element and a second heating element, a detector configured to detect a temperature of the heater, a switcher configured to switch which of the first heating element and the second heating element is supplied power from a power supply, and a controller configured to control the switcher. The controller is configured to execute a first control of determining a first electric energy and a second electric energy based on the temperature of the heater detected by the detector and a target temperature of the heater, and a second control of causing the switcher to switch between a state in which power is supplied to the first heating element by the first electric energy and a state in which power is supplied to the second heating element by the second electric energy.Type: ApplicationFiled: June 6, 2023Publication date: October 5, 2023Inventors: Kohei Wakatsu, Kazuhiro Doda
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Patent number: 11774891Abstract: The heater including a substrate, a first heat generation member, a second heat generation member having a length substantially a same in a longitudinal direction as a length of the first heat generation member, a third heat generation member having a length shorter than lengths of the first heat generation member and the second heat generation member in the longitudinal direction, and a fourth heat generation member having a length shorter than length of the third heat generation member in the longitudinal direction, wherein the first heat generation member, the second heat generation member, the third heat generation member and the fourth heat generation member are arranged on the substrate.Type: GrantFiled: August 9, 2022Date of Patent: October 3, 2023Assignee: Canon Kabushiki KaishaInventors: Kazuhiro Doda, Ken Nakagawa, Tsuguhiro Yoshida, Yutaka Sato, Kohei Wakatsu
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Publication number: 20230259057Abstract: A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.Type: ApplicationFiled: April 25, 2023Publication date: August 17, 2023Inventors: Kazuhiro Doda, Tsuguhiro Yoshida, Kohei Wakatsu
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Patent number: 11709446Abstract: A fixing unit includes a tubular film, a pressure roller, a heater including a first heating element and a second heating element, a detector configured to detect a temperature of the heater, a switcher configured to switch which of the first heating element and the second heating element is supplied power from a power supply, and a controller configured to control the switcher. The controller is configured to execute a first control of determining a first electric energy and a second electric energy based on the temperature of the heater detected by the detector and a target temperature of the heater, and a second control of causing the switcher to switch between a state in which power is supplied to the first heating element by the first electric energy and a state in which power is supplied to the second heating element by the second electric energy.Type: GrantFiled: March 4, 2022Date of Patent: July 25, 2023Assignee: Canon Kabushiki KaishaInventors: Kohei Wakatsu, Kazuhiro Doda
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Patent number: 11669032Abstract: A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.Type: GrantFiled: November 2, 2021Date of Patent: June 6, 2023Assignee: Canon Kabushiki KaishaInventors: Kazuhiro Doda, Tsuguhiro Yoshida, Kohei Wakatsu
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Publication number: 20230065569Abstract: A fixing device includes a heater provided with a first heat generator on a substrate and a second heat generator of which a length in a longitudinal direction is shorter than that of the first heat generator, a temperature detector of the heater, a switch for switching a power supply path from an AC power source to the first heat generator or the second heat generator. A controller for controlling the switch to supply power to the first heat generator or the second heat generator. The controller executes a first control in which the switch supplies the power to the first heat generator, and switches a second control in which the switch supplies the power alternately to the first heat generator or the second heat generator when the detected temperature reaches a threshold temperature.Type: ApplicationFiled: August 9, 2022Publication date: March 2, 2023Inventors: Kohei Wakatsu, Tsuguhiro Yoshida
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Publication number: 20230067803Abstract: A fixing device includes a substrate, a first heat generator, a second heat generator with a length in a longitudinal direction of the substrate equal to a length of the first heat generator; and a third heat generator with a length shorter than the lengths of the first and second heat generators, a soaking member with a positioning portion in the longitudinal direction. In a short side direction of the substrate, the first heat generator is arranged at one end side, the second heat generator is arranged at the other end side, and the third heat generator is arranged between the first and second heat generators. The soaking member is arranged between the heater and a holder in a thickness direction. As seen in the short side direction, the positioning portion is positioned outside of an area corresponding to the third heat generator and inside of an area corresponding to the first heat generator.Type: ApplicationFiled: August 5, 2022Publication date: March 2, 2023Inventors: Tsuguhiro Yoshida, Kohei Wakatsu
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Patent number: 11531294Abstract: An image forming apparatus includes a fixing device having a heater, a first temperature detection unit, a pair of second temperature detection units, a pair of first sheet-width detection units, a pair of second sheet-width detection units, and a control unit. The heater includes a first heat generating element, a second heat generating element having a length smaller than a length of the first heat generating element in a longitudinal direction, and a third heat generating element having a length smaller than the length of the second heat generating element in the longitudinal direction. The control unit controls a temperature of the heater based on a detection result of the pair of first sheet-width detection units, a detection result of the pair of second sheet-width detection units, and a detection result of the pair of second temperature detection units.Type: GrantFiled: November 29, 2021Date of Patent: December 20, 2022Assignee: Canon Kabushiki KaishaInventors: Tsuguhiro Yoshida, Kohei Wakatsu, Kazuhiro Doda, Yutaka Sato, Ken Nakagawa
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Publication number: 20220390882Abstract: The heater including a substrate, a first heat generation member, a second heat generation member having a length substantially a same in a longitudinal direction as a length of the first heat generation member, a third heat generation member having a length shorter than lengths of the first heat generation member and the second heat generation member in the longitudinal direction, and a fourth heat generation member having a length shorter than length of the third heat generation member in the longitudinal direction, wherein the first heat generation member, the second heat generation member, the third heat generation member and the fourth heat generation member are arranged on the substrate.Type: ApplicationFiled: August 9, 2022Publication date: December 8, 2022Inventors: Kazuhiro Doda, Ken Nakagawa, Tsuguhiro Yoshida, Yutaka Sato, Kohei Wakatsu
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Patent number: 11507001Abstract: An image forming apparatus is operable in a first small-sheet printing in which power is supplied to the first heat generating element and the second heat generating element and in a second small-sheet printing in which power is supplied to the first heat generating element and the third heat generating element. A first power ratio, which is a proportion of power supplied to the first heat generating element to power supplied to the second heat generating element in the first small-sheet printing, is higher than a second power ratio, which is a proportion of power supplied to the first heat generating element to power supplied to the third heat generating element in the second small-sheet printing.Type: GrantFiled: July 8, 2021Date of Patent: November 22, 2022Assignee: Canon Kabushiki KaishaInventors: Tsuguhiro Yoshida, Kazuhiro Doda, Kohei Wakatsu
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Publication number: 20220365475Abstract: An image forming apparatus includes a first rotating member, a heater, a second rotating member, a detecting unit, a switching unit, a controlling unit, and a power source device. In a first period, a resultant current of first and third currents is supplied to a first heat generating element, and the resultant current in a unit cycle of a first period is a current at which a first current supplying timing and timings of a maximum and a minimum of the third current do not overlap with each other. In a second period, a resultant current of second and third currents is supplied to a second heat generating element, and the resultant current in a unit cycle of the second period is a current at which a second current supplying timing and the timings of the maximum and the minimum of the third current overlap with each other.Type: ApplicationFiled: May 10, 2022Publication date: November 17, 2022Inventors: Nozomu Nakajima, Atsushi Nakamoto, Kohei Wakatsu
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Publication number: 20220308509Abstract: A fixing unit includes a tubular film, a pressure roller, a heater including a first heating element and a second heating element, a detector configured to detect a temperature of the heater, a switcher configured to switch which of the first heating element and the second heating element is supplied power from a power supply, and a controller configured to control the switcher. The controller is configured to execute a first control of determining a first electric energy and a second electric energy based on the temperature of the heater detected by the detector and a target temperature of the heater, and a second control of causing the switcher to switch between a state in which power is supplied to the first heating element by the first electric energy and a state in which power is supplied to the second heating element by the second electric energy.Type: ApplicationFiled: March 4, 2022Publication date: September 29, 2022Inventors: Kohei Wakatsu, Kazuhiro Doda
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Patent number: 11442385Abstract: The heater including a substrate, a first heat generation member, a second heat generation member having a length substantially a same in a longitudinal direction as a length of the first heat generation member, a third heat generation member having a length shorter than lengths of the first heat generation member and the second heat generation member in the longitudinal direction, and a fourth heat generation member having a length shorter than length of the third heat generation member in the longitudinal direction, wherein the first heat generation member, the second heat generation member, the third heat generation member and the fourth heat generation member are arranged on the substrate.Type: GrantFiled: June 21, 2021Date of Patent: September 13, 2022Assignee: Canon Kabushiki KaishaInventors: Kazuhiro Doda, Ken Nakagawa, Tsuguhiro Yoshida, Yutaka Sato, Kohei Wakatsu
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Patent number: 11281135Abstract: In a case where fixing processing is performed continuously on sheets having a width that is shorter than a length of a heat generation member in a longitudinal direction and longer than a length of another heat generation member in the longitudinal directions, the CPU determines a timing to switch between the heat generation member and the another heat generation member by a heat generation member switching device based on information relating to a size of the sheet.Type: GrantFiled: January 15, 2021Date of Patent: March 22, 2022Assignee: Canon Kabushiki KaishaInventors: Yutaka Sato, Kazuhiro Doda, Kohei Wakatsu, Tsuguhiro Yoshida
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Publication number: 20220082969Abstract: An image forming apparatus includes a fixing device having a heater that includes a first heating element, a second heating element having a length smaller than the first heating element length, and a third heating element having a length smaller than the second heating element length. The image forming apparatus further includes a first temperature detection unit, a control unit, second temperature detection units, first and second sheet-width detection units, and a determination unit. The control unit controls a heater temperature based on the first temperature detection unit detection result. The determination unit determines a width of the recording material based on a detection result of the first sheet-width detection units, a detection result of the second sheet-width detection units, and a detection result of the second temperature detection units.Type: ApplicationFiled: November 29, 2021Publication date: March 17, 2022Inventors: Tsuguhiro Yoshida, Kohei Wakatsu, Kazuhiro Doda, Yutaka Sato, Ken Nakagawa
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Publication number: 20220057736Abstract: A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.Type: ApplicationFiled: November 2, 2021Publication date: February 24, 2022Inventors: Kazuhiro Doda, Tsuguhiro Yoshida, Kohei Wakatsu
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Patent number: 11221575Abstract: An image forming apparatus includes a fixing device having a heater that includes a first heating element, a second heating element having a length smaller than the first heating element length, and a third heating element having a length smaller than the second heating element length. The image forming apparatus further includes a first temperature detection unit, a control unit, second temperature detection units, first and second sheet-width detection units, and a determination unit. The control unit controls a heater temperature based on the first temperature detection unit detection result. The determination unit determines a width of the recording material based on a detection result of the first sheet-width detection units, a detection result of the second sheet-width detection units, and a detection result of the second temperature detection units.Type: GrantFiled: September 3, 2020Date of Patent: January 11, 2022Assignee: Canon Kabushiki KaishaInventors: Tsuguhiro Yoshida, Kohei Wakatsu, Kazuhiro Doda, Yutaka Sato, Ken Nakagawa