Patents by Inventor Keiji Tomizawa

Keiji Tomizawa 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: 11712891
    Abstract: A liquid ejection head that can suppress variation in the circulation flow rate or the pressure of the liquid among a plurality of pressure chambers and suppress a difference in temperature distribution between adjacent element substrates to suppress image unevenness includes a plurality of ejection modules including an element substrate in which a plurality of ejection orifices that eject a liquid are aligned in an array. In one ejection module of the ejection modules adjacent to each other, the liquid is supplied from one side of an ejection orifice array, and the liquid is collected from the other side of the ejection orifice array, and in the other ejection module of the ejection modules adjacent to each other, the liquid is supplied from the other side, and the liquid is collected from the one side.
    Type: Grant
    Filed: June 15, 2021
    Date of Patent: August 1, 2023
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshihiro Hamada, Keiji Tomizawa, Yoshiyuki Nakagawa, Akiko Hammura, Shuzo Iwanaga
  • Publication number: 20230103488
    Abstract: An aspect of the present invention is a liquid ejection apparatus including: a liquid ejection head including a heating element, a first protection layer, a second protection layer that functions as a first electrode, a second electrode that is electrically connected to the first electrode, and an ejection port; and a control unit configured to perform control of setting a potential difference between potentials of the first and second electrodes to a predetermined value by changing at least one of the potentials of the first electrode and the second electrode, in which the control unit sets the potential difference to a first value in a case where printing is performed, and the control unit sets the potential difference to a second value different from the first value and feeds power to at least one of a plurality of the heating elements in a case where printing is not performed.
    Type: Application
    Filed: August 9, 2022
    Publication date: April 6, 2023
    Inventors: So Aizawa, Keiji Tomizawa, Tomoki Ishiwata
  • Publication number: 20230070795
    Abstract: One embodiment of the present invention is a liquid ejection apparatus having: a liquid ejection head including a heating element, a first protection layer that blocks contact between the heating element and liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid; and a control unit configured to perform control of setting a potential difference between the first electrode and the second electrode to a predetermined value in each of aging and printing by changing at least one of potentials of the first electrode and the second electrode, wherein ?Va??Vp is satisfied in the case where the potential difference in the aging is represented by ?Va and the potential difference in the printing is represented by ?Vp.
    Type: Application
    Filed: August 31, 2022
    Publication date: March 9, 2023
    Inventors: Keiji Tomizawa, Yoshinori Misumi, Yuzuru Ishida, Shuzo Iwanaga
  • Patent number: 11597203
    Abstract: In a liquid ejection head in which ejection modules are arrayed on a flow path forming member, each ejection module includes a recording element substrate provided on a support member. The recording element substrate includes a liquid supply channel, a liquid collection channel, and ejection ports. The support member includes supply-side liquid communication ports communicating with the liquid supply channel and collection-side liquid communication ports communicating with the liquid collection channel. The supply-side liquid communication ports and the collection-side liquid communication ports are alternately provided along the direction in which the ejection modules are arrayed. The closest pair of liquid communication ports in the adjacent ends of two adjacent ejection modules are both supply-side or collection-side liquid communication ports.
    Type: Grant
    Filed: June 22, 2021
    Date of Patent: March 7, 2023
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Shuzo Iwanaga, Akiko Hammura, Yoshihiro Hamada
  • Publication number: 20230007995
    Abstract: An aspect of the present disclosure is a liquid ejection apparatus including: a liquid ejection head including a conversion element that generates energy required to eject liquid, a first protection layer that blocks contact between the conversion element and the liquid, a second protection layer that partially covers the first protection layer and functions as a first electrode, a second electrode that is electrically connected to the first electrode through the liquid, and an ejection port that ejects the liquid, and a control unit configured to control a potential difference between the first electrode and the second electrode in printing to a predetermined value by changing at least one of potentials of the first electrode and the second electrode. The control unit sets the potential difference based on at least one of a condition and a configuration of the liquid ejection head.
    Type: Application
    Filed: July 6, 2022
    Publication date: January 12, 2023
    Inventors: Yoshihiro Hamada, Tomoki Ishiwata, So Aizawa, Keiji Tomizawa
  • Publication number: 20210402765
    Abstract: In a liquid ejection head in which ejection modules are arrayed on a flow path forming member, each ejection module includes a recording element substrate provided on a support member. The recording element substrate includes a liquid supply channel, a liquid collection channel, and ejection ports. The support member includes supply-side liquid communication ports communicating with the liquid supply channel and collection-side liquid communication ports communicating with the liquid collection channel. The supply-side liquid communication ports and the collection-side liquid communication ports are alternately provided along the direction in which the ejection modules are arrayed. The closest pair of liquid communication ports in the adjacent ends of two adjacent ejection modules are both supply-side or collection-side liquid communication ports.
    Type: Application
    Filed: June 22, 2021
    Publication date: December 30, 2021
    Inventors: Keiji Tomizawa, Shuzo Iwanaga, Akiko Hammura, Yoshihiro Hamada
  • Publication number: 20210402770
    Abstract: Provided is a liquid ejection head that can suppress variation in the circulation flow rate or the pressure of the liquid among a plurality of pressure chambers and suppress a difference in temperature distribution between adjacent element substrates to suppress image unevenness. The liquid ejection head includes a plurality of ejection modules including an element substrate in which a plurality of ejection orifices that eject a liquid are aligned in an array. In one ejection module of the ejection modules adjacent to each other, the liquid is supplied from one side of an ejection orifice array, and the liquid is collected from the other side of the ejection orifice array, and in the other ejection module of the ejection modules adjacent to each other, the liquid is supplied from the other side, and the liquid is collected from the one side.
    Type: Application
    Filed: June 15, 2021
    Publication date: December 30, 2021
    Inventors: Yoshihiro Hamada, Keiji Tomizawa, Yoshiyuki Nakagawa, Akiko Hammura, Shuzo Iwanaga
  • Patent number: 11077658
    Abstract: A liquid injection head improving electric reliability includes: a substrate including: energy generating elements configured to apply energy for ejection to a liquid, and a substrate upper surface on which terminals respectively connected to electric wirings are provided, an ejection port forming member having: an ejection port forming surface in which the ejection ports for ejecting a liquid are formed, and a back surface on a side opposite to the ejection port forming surface, which is arranged so as to opposite to the substrate upper surface, and a sealant configured to cover connecting portions between the electric wirings and the terminals.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: August 3, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomoki Ishiwata, Shuzo Iwanaga, Masaki Oikawa, Keiji Tomizawa, Tomohiro Sato, Akiko Hammura, Chiaki Muraoka, Shimpei Yoshikawa
  • Publication number: 20200070513
    Abstract: A liquid injection head improving electric reliability includes: a substrate including: energy generating elements configured to apply energy for ejection to a liquid, and a substrate upper surface on which terminals respectively connected to electric wirings are provided, an ejection port forming member having: an ejection port forming surface in which the ejection ports for ejecting a liquid are formed, and a back surface on a side opposite to the ejection port forming surface, which is arranged so as to opposite to the substrate upper surface, and a sealant configured to cover connecting portions between the electric wirings and the terminals.
    Type: Application
    Filed: August 29, 2019
    Publication date: March 5, 2020
    Inventors: Tomoki Ishiwata, Shuzo Iwanaga, Masaki Oikawa, Keiji Tomizawa, Tomohiro Sato, Akiko Hammura, Chiaki Muraoka, Shimpei Yoshikawa
  • Patent number: 10322578
    Abstract: A liquid ejection head includes a substrate including an electrically insulating film, an energy generating element provided on the substrate and configured to generate energy used to eject a liquid, a flow path formed through the substrate and communicating with an ejection port configured to eject a liquid, and a wiring layer formed in the electrically insulating film of the substrate, used to drive the energy generating element, provided apart from a wall defining the flow path, and provided to surround the flow path in a plan view of the substrate.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: June 18, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomoko Kudo, Takaaki Yamaguchi, Keiji Tomizawa, Masaki Oikawa, Yoshihiro Hamada, Masataka Sakurai
  • Patent number: 10308018
    Abstract: A printing apparatus comprises: a plurality of printing elements; driving circuits that have at least one source follower transistor and correspond to each of the plurality of printing elements; and a control unit configured to, in a case where a number of printing elements driven simultaneously does not exceed a predetermined number, perform a first control for driving the at least one source follower transistor by a fixed pulse width irrespective of the number of printing elements driven simultaneously, and, in a case where the number of printing elements driven simultaneously exceed the predetermined number, perform a second control for changing a pulse width to drive the at least one source follower transistor based on the number of printing elements driven simultaneously.
    Type: Grant
    Filed: October 4, 2017
    Date of Patent: June 4, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yosuke Miura, Keiji Tomizawa
  • Patent number: 10300698
    Abstract: A liquid ejection head includes a substrate, a heat generating resistor element arranged on the substrate and a flow channel forming member for forming a flow channel. The flow channel forming member has a side wall surrounding at least part of the heat generating resistor element. The heat generating resistor element has a pair of oppositely disposed sides and a pair of electrical connection regions which extend along the respective ones of the pair of sides and are separated from the respective ones of the pair of sides by a distance. The side wall has at least one concave corner which is comprised of a curved surface or a surface extending obliquely to the pair of sides and the heat generating resistor element has at least one convex corner which faces the at least one concave corner of the side wall and is rounded or chamfered.
    Type: Grant
    Filed: May 30, 2018
    Date of Patent: May 28, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Masataka Sakurai, Akiko Hammura
  • Publication number: 20180361734
    Abstract: A liquid ejection head includes a substrate including an electrically insulating film, an energy generating element provided on the substrate and configured to generate energy used to eject a liquid, a flow path formed through the substrate and communicating with an ejection port configured to eject a liquid, and a wiring layer formed in the electrically insulating film of the substrate, used to drive the energy generating element, provided apart from a wall defining the flow path, and provided to surround the flow path in a plan view of the substrate.
    Type: Application
    Filed: June 12, 2018
    Publication date: December 20, 2018
    Inventors: Tomoko Kudo, Takaaki Yamaguchi, Keiji Tomizawa, Masaki Oikawa, Yoshihiro Hamada, Masataka Sakurai
  • Publication number: 20180345668
    Abstract: A liquid ejection head includes a substrate, a heat generating resistor element arranged on the substrate and a flow channel forming member for forming a flow channel. The flow channel forming member has a side wall surrounding at least part of the heat generating resistor element. The heat generating resistor element has a pair of oppositely disposed sides and a pair of electrical connection regions which extend along the respective ones of the pair of sides and are separated from the respective ones of the pair of sides by a distance. The side wall has at least one concave corner which is comprised of a curved surface or a surface extending obliquely to the pair of sides and the heat generating resistor element has at least one convex corner which faces the at least one concave corner of the side wall and is rounded or chamfered.
    Type: Application
    Filed: May 30, 2018
    Publication date: December 6, 2018
    Inventors: Keiji Tomizawa, Masataka Sakurai, Akiko Hammura
  • Patent number: 9969163
    Abstract: A liquid discharge head includes a discharge unit that discharges a liquid as a result of electric energy being supplied to the discharge unit, a first wiring member that is joined to the discharge unit and that includes a plurality of first joining terminals each capable of transmitting the electric energy to the discharge unit, and a second wiring member that is electrically joined to the first wiring member and that includes a plurality of second joining terminals. At least three of the plurality of first joining terminals are inspection terminals that are short-circuited, and the second joining terminals are connected to contact terminals to each of which an external signal can be input.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: May 15, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Chiaki Muraoka, Keiji Tomizawa, Takuma Kodoi
  • Publication number: 20180111370
    Abstract: A printing apparatus comprises: a plurality of printing elements; driving circuits that have at least one source follower transistor and correspond to each of the plurality of printing elements; and a control unit configured to, in a case where a number of printing elements driven simultaneously does not exceed a predetermined number, perform a first control for driving the at least one source follower transistor by a fixed pulse width irrespective of the number of printing elements driven simultaneously, and, in a case where the number of printing elements driven simultaneously exceed the predetermined number, perform a second control for changing a pulse width to drive the at least one source follower transistor based on the number of printing elements driven simultaneously.
    Type: Application
    Filed: October 4, 2017
    Publication date: April 26, 2018
    Inventors: Yosuke Miura, Keiji Tomizawa
  • Patent number: 9889650
    Abstract: There are provided a liquid ejecting head, an ejecting element substrate and a liquid ejecting apparatus that can suppress degradation in print quality. Therefore in an ejecting element substrate arranged the closest to the center of a support member, a flow resistance of a flow passage corresponding to an ejection opening of an ejection opening array arranged the closest to the center of the ejecting element substrate is made high.
    Type: Grant
    Filed: May 16, 2016
    Date of Patent: February 13, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takuma Kodoi, Keiji Tomizawa
  • Patent number: 9731503
    Abstract: A liquid discharge head includes a substrate having an element that discharges liquid by generating thermal energy to generate an air bubble in the liquid, and a liquid supply port for supplying the liquid to the element, and a flow path forming assembly including a flow path forming member having a discharge port for discharging the liquid and, between the substrate and the flow path forming member, a pressure chamber including the element disposed adjacent thereto and a flow path causing the pressure chamber and the liquid supply port to communicate with each other. In addition, an interlayer is provided on a joining portion of the substrate and the flow path forming member and provided so as to protrude from between the substrate and the flow path forming member into the flow path, and a protection layer including metal is formed so as to cover the element.
    Type: Grant
    Filed: April 22, 2013
    Date of Patent: August 15, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takuma Kodoi, Keiji Tomizawa, Chiaki Muraoka
  • Patent number: 9676181
    Abstract: A method for stabilizing a refilling speed within a predetermined range even with various physical properties of liquid to be ejected is provided for a liquid ejection head using a thermal system. To achieve this, a drive pulse is controlled for each nozzle array according to the combination of a predetermined material and structure of a bubble-generating chamber and the physical property of the liquid to be ejected such that an amount of an overshoot and the refilling speed are within a predetermined range.
    Type: Grant
    Filed: July 28, 2016
    Date of Patent: June 13, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Takuma Kodoi, Chiaki Muraoka
  • Publication number: 20170136769
    Abstract: A liquid discharge head includes a discharge unit that discharges a liquid as a result of electric energy being supplied to the discharge unit, a first wiring member that is joined to the discharge unit and that includes a plurality of first joining terminals each capable of transmitting the electric energy to the discharge unit, and a second wiring member that is electrically joined to the first wiring member and that includes a plurality of second joining terminals. At least three of the plurality of first joining terminals are inspection terminals that are short-circuited, and the second joining terminals are connected to contact terminals to each of which an external signal can be input.
    Type: Application
    Filed: November 9, 2016
    Publication date: May 18, 2017
    Inventors: Chiaki Muraoka, Keiji Tomizawa, Takuma Kodoi