Patents by Inventor Tamotsu Shimizu

Tamotsu Shimizu 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).

  • Publication number: 20210364944
    Abstract: A developing device includes a developer container, a developer carrier, and first and second stirring/conveying members. The developer container includes a first partition wall partitioning between the two conveying chambers longitudinally, a first communication portion for passing developer from the first to the second conveying chamber, a second communication portion for passing developer from the second to the first conveying chamber, a developer supply port for supplying developer in, a developer discharge portion for discharging excessive developer, a second partition wall arranged, adjacent to the regulating portion, downstream of the second communication portion to partition between the first conveying chamber and the regulating portion, and a shield portion connected to the two partition walls to bridge between them to shield a top part of the second communication portion. A gap is formed between an upper end part of the shield portion and the inner surface of the developer container.
    Type: Application
    Filed: May 17, 2021
    Publication date: November 25, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Masashi FUJISHIMA, Norio KUBO, Asami SASAKI, Yasuhiro TAUCHI, Tamotsu SHIMIZU, Akira MATAYOSHI, Masaki KADOTA, Koji SUENAMI, Yuji TOYOTA
  • Publication number: 20210364951
    Abstract: A developing device includes a developer container, a developer carrier, and first and second members for stirring/conveying. The developer container includes a first partition wall between first and second chambers, a communication portion through which those chambers communicate at opposite ends of the first partition wall, a developer supply port, and a developer discharge portion. The first member stirs and conveys developer in the first chamber in a first direction. The second member stirs and conveys developer in the second chamber in a second direction and includes a regulating portion and a discharging blade. The developer container includes a second partition wall between the first chamber and the regulating portion. The gap from the upper end of the second partition wall to the inner surface of the developer container is larger than the gap thereto from the upper ends of a first helical blade and the regulating portion.
    Type: Application
    Filed: May 17, 2021
    Publication date: November 25, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Asami SASAKI, Akira MATAYOSHI, Norio KUBO, Koji SUENAMI, Yuji TOYOTA, Tamotsu SHIMIZU, Masashi FUJISHIMA, Yasuhiro TAUCHI
  • Patent number: 11163243
    Abstract: A bias condition determiner executes, in order, a first direct current voltage determination mode (first DC calibration) for determining a provisional reference direct current voltage that is a provisional reference for a direct current voltage of a developing bias applied to a developing roller, an inter-peak voltage determination mode (AC calibration) for determining a reference inter-peak voltage that is a reference for an inter-peak voltage of an alternating current voltage of the developing bias applied to the developing roller in an image forming operation, and a second direct current voltage determination mode (second DC calibration) for determining a reference direct current voltage that is a reference for the direct current voltage of the developing bias applied to the developing roller in the image forming operation.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: November 2, 2021
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Norio Kubo, Asami Sasaki, Yasuhiro Tauchi, Yuji Toyota
  • Patent number: 11150574
    Abstract: An image forming apparatus includes a plurality of image forming units, a developing voltage power supply, a current detection unit, and a control unit. The image forming units form an image by superimposing a toner image of a same color and a same type, and substantially same development conditions are set to evenly divide an image density among the image forming units. The control unit detects whether there is an anomaly in the image forming unit based on detecting a DC component of developing current, being either of current flowing through a non-exposed portion of an image carrier during image formation, and current flowing through an exposed portion of the image carrier. When an anomaly is detected in any image forming unit, the control unit inhibits use of the image forming unit, and resets the development conditions to evenly divide an image density among the usable image forming units.
    Type: Grant
    Filed: February 18, 2021
    Date of Patent: October 19, 2021
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Kazunori Tanaka, Kanako Morimoto, Shiro Kaneko
  • Patent number: 11143980
    Abstract: An image forming apparatus includes a plurality of image forming units, a developing voltage power supply, a density detection device, a current detection unit, and a control unit. The plurality of image forming units form an image and substantially same development conditions are set to evenly divide an image density among the image forming units. The control unit detects whether there is an anomaly in a developing device, based on a toner charge amount calculated based on a DC component of developing current when a reference image is formed on an image carrier by each of the developing devices and a density of the reference image. When an anomaly is detected in any of the developing devices, the control unit inhibits use of the image forming unit including the developing device, and resets the development conditions to evenly divide the image density among the usable image forming units.
    Type: Grant
    Filed: February 18, 2021
    Date of Patent: October 12, 2021
    Assignee: YOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Kanako Morimoto, Kazunori Tanaka, Kenichi Tamaki
  • Patent number: 11143979
    Abstract: Provided is an image forming apparatus having a simple configuration capable of measuring a toner current included in a developing current and accurately calculating a toner charge amount based on the measurement result. A developing device has a developer carrier that carries a two-component developer including a magnetic carrier and toner. A developing voltage power supply applies a developing voltage obtained by superimposing an AC voltage on a DC voltage on the developer carrier. A control unit estimates a toner charge amount based on a toner current calculated by subtracting a carrier current from a developing current detected by a current detecting unit when a reference image is formed during non-image formation, and a toner developing amount calculated from the density of a reference image detected by a density detecting device.
    Type: Grant
    Filed: November 15, 2020
    Date of Patent: October 12, 2021
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Tamotsu Shimizu, Mitsuhiro Hashimoto, Takahiro Okubo, Yohei Wakasa, Kazuhiro Nakachi
  • Publication number: 20210302869
    Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a bias voltage to the development device; a calculating section which calculates a surface potential of the photosensitive drum based on a development current flowing in the development device; and an estimating section which estimates a fogging toner amount. The fogging toner amount is an amount of toner moved due to fogging. When the fogging toner amount estimated by the estimating section is less than a prescribed threshold, the calculating section calculates a value of the bias voltage at which the development current stops flowing as the surface potential.
    Type: Application
    Filed: March 23, 2021
    Publication date: September 30, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazunori TANAKA, Yoshihiro YAMAGISHI, Tamotsu SHIMIZU
  • Publication number: 20210302859
    Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a prescribed bias voltage to the development device; and a calculating section which calculates a surface potential of the photosensitive drum based on a development current flowing in the development device. The calculating section calculates, as the surface potential, a bias voltage at which a non-charging development current that flows in the development device in an uncharged state in which the charger has not charged the photosensitive drum is equal to a charging development current that flows in the development device in a charged state in which the charger has charged the photosensitive drum.
    Type: Application
    Filed: March 24, 2021
    Publication date: September 30, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazunori TANAKA, Yoshihiro YAMAGISHI, Tamotsu SHIMIZU
  • Publication number: 20210302866
    Abstract: A bias condition determiner executes a direct current voltage determination mode (DC calibration) for determining a reference direct current voltage that is a reference for a direct current voltage of a developing bias applied to a developing roller in an image forming operation and an inter-peak voltage determination mode (AC calibration) for determining a reference inter-peak voltage that is a reference for an inter-peak voltage of an alternating current voltage of the developing bias applied to the developing roller in the image forming operation. A calibration executor determines whether the inter-peak voltage determination mode needs to be executed in accordance with a value of the reference direct current voltage.
    Type: Application
    Filed: March 19, 2021
    Publication date: September 30, 2021
    Inventors: Tamotsu SHIMIZU, Norio KUBO, Asami SASAKI, Yasuhiro TAUCHI, Yuji TOYOTA
  • Publication number: 20210302867
    Abstract: A bias condition determiner executes, in order, a first direct current voltage determination mode (first DC calibration) for determining a provisional reference direct current voltage that is a provisional reference for a direct current voltage of a developing bias applied to a developing roller, an inter-peak voltage determination mode (AC calibration) for determining a reference inter-peak voltage that is a reference for an inter-peak voltage of an alternating current voltage of the developing bias applied to the developing roller in an image forming operation, and a second direct current voltage determination mode (second DC calibration) for determining a reference direct current voltage that is a reference for the direct current voltage of the developing bias applied to the developing roller in the image forming operation.
    Type: Application
    Filed: March 19, 2021
    Publication date: September 30, 2021
    Inventors: Tamotsu Shimizu, Norio Kubo, Asami Sasaki, Yasuhiro Tauchi, Yuji Toyota
  • Publication number: 20210302868
    Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a bias voltage to the development device; an electric current measuring section which measures a development current flowing in the development device; and a calculating section which calculates a surface potential of the photosensitive drum based on the development current. The charger applies charging biases to the photosensitive drum. The electric current measuring section measures a corresponding value of the development current for each development bias voltage applied to the development device.
    Type: Application
    Filed: March 23, 2021
    Publication date: September 30, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazunori TANAKA, Yoshihiro YAMAGISHI, Tamotsu SHIMIZU
  • Publication number: 20210302870
    Abstract: An image forming apparatus includes: a development device that develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger that charges the photosensitive drum; a development power supply that applies a prescribed bias voltage to the development device; an electric current measuring section that measures a development current flowing in the development device; and a calculating section that calculates a surface potential of the photosensitive drum based on the development current. The development device sequentially forms a plurality of image formation toner images on respective sheets of a recording medium. The image formation toner images each are a toner image for image formation. The electric current measuring section measures the development current in a period during which the image formation toner images are not formed.
    Type: Application
    Filed: March 23, 2021
    Publication date: September 30, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazunori TANAKA, Yoshihiro YAMAGISHI, Tamotsu SHIMIZU
  • Patent number: 11131943
    Abstract: An image forming apparatus includes: a development device that develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger that charges the photosensitive drum; a development power supply that applies a prescribed bias voltage to the development device; an electric current measuring section that measures a development current flowing in the development device; and a calculating section that calculates a surface potential of the photosensitive drum based on the development current. The development device sequentially forms a plurality of image formation toner images on respective sheets of a recording medium. The image formation toner images each are a toner image for image formation. The electric current measuring section measures the development current in a period during which the image formation toner images are not formed.
    Type: Grant
    Filed: March 23, 2021
    Date of Patent: September 28, 2021
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Kazunori Tanaka, Yoshihiro Yamagishi, Tamotsu Shimizu
  • Patent number: 11131942
    Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a bias voltage to the development device; an electric current measuring section which measures a development current flowing in the development device; and a calculating section which calculates a surface potential of the photosensitive drum based on the development current. The charger applies charging biases to the photosensitive drum. The electric current measuring section measures a corresponding value of the development current for each development bias voltage applied to the development device.
    Type: Grant
    Filed: March 23, 2021
    Date of Patent: September 28, 2021
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Kazunori Tanaka, Yoshihiro Yamagishi, Tamotsu Shimizu
  • Patent number: 11112732
    Abstract: A bias condition determination portion of an image forming device executes each of: a first approximation expression determination operation that respectively acquires the DC component of the development current with at least three peak-to-peak voltages included in a first measurement range and determines a first expression showing a relation between the peak-to-peak voltage and the DC component of the acquired development current, a second approximation expression determination operation that respectively acquires the DC component of the development current with at least three peak-to-peak voltages included in a second measurement range larger than the first measurement range and determines a second approximation expression showing a relation between the peak-to-peak voltage and the DC component of the acquired development current, and a reference voltage determination operation that determines, as a reference peak-to-peak voltage, the peak-to-peak voltage at an intersection where the first approximation exp
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: September 7, 2021
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Yasuhiro Tauchi, Akira Matayoshi, Masashi Fujishima
  • Patent number: 11112722
    Abstract: A bias condition determiner executes a direct current voltage determination mode (DC calibration) for determining a reference direct current voltage that is a reference for a direct current voltage of a developing bias applied to a developing roller in an image forming operation and an inter-peak voltage determination mode (AC calibration) for determining a reference inter-peak voltage that is a reference for an inter-peak voltage of an alternating current voltage of the developing bias applied to the developing roller in the image forming operation. A calibration executor determines whether the inter-peak voltage determination mode needs to be executed in accordance with a value of the reference direct current voltage.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: September 7, 2021
    Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
    Inventors: Tamotsu Shimizu, Norio Kubo, Asami Sasaki, Yasuhiro Tauchi, Yuji Toyota
  • Publication number: 20210263442
    Abstract: An image forming apparatus includes a plurality of image forming units, a developing voltage power supply, a current detection unit, and a control unit. The image forming units form an image by superimposing a toner image of a same color and a same type, and substantially same development conditions are set to evenly divide an image density among the image forming units. The control unit detects whether there is an anomaly in the image forming unit based on detecting a DC component of developing current, being either of current flowing through a non-exposed portion of an image carrier during image formation, and current flowing through an exposed portion of the image carrier. When an anomaly is detected in any image forming unit, the control unit inhibits use of the image forming unit, and resets the development conditions to evenly divide an image density among the usable image forming units.
    Type: Application
    Filed: February 18, 2021
    Publication date: August 26, 2021
    Inventors: Tamotsu SHIMIZU, Kazunori TANAKA, Kanako MORIMOTO, Shiro KANEKO
  • Publication number: 20210263441
    Abstract: An image forming apparatus includes a plurality of image forming units, a developing voltage power supply, a density detection device, a current detection unit, and a control unit. The plurality of image forming units form an image and substantially same development conditions are set to evenly divide an image density among the image forming units. The control unit detects whether there is an anomaly in a developing device, based on a toner charge amount calculated based on a DC component of developing current when a reference image is formed on an image carrier by each of the developing devices and a density of the reference image. When an anomaly is detected in any of the developing devices, the control unit inhibits use of the image forming unit including the developing device, and resets the development conditions to evenly divide the image density among the usable image forming units.
    Type: Application
    Filed: February 18, 2021
    Publication date: August 26, 2021
    Inventors: Tamotsu SHIMIZU, Kanako Morimoto, Kazunori Tanaka, Kenichi Tamaki
  • Publication number: 20210255566
    Abstract: A bias condition determination portion of an image forming device executes each of: a first approximation expression determination operation that respectively acquires the DC component of the development current with at least three peak-to-peak voltages included in a first measurement range and determines a first expression showing a relation between the peak-to-peak voltage and the DC component of the acquired development current, a second approximation expression determination operation that respectively acquires the DC component of the development current with at least three peak-to-peak voltages included in a second measurement range larger than the first measurement range and determines a second approximation expression showing a relation between the peak-to-peak voltage and the DC component of the acquired development current, and a reference voltage determination operation that determines, as a reference peak-to-peak voltage, the peak-to-peak voltage at an intersection where the first approximation exp
    Type: Application
    Filed: February 9, 2021
    Publication date: August 19, 2021
    Inventors: Tamotsu SHIMIZU, Yasuhiro TAUCHI, Akira MATAYOSHI, Masashi FUJISHIMA
  • Publication number: 20210240102
    Abstract: An image forming apparatus includes a toner charge amount predictor, a toner developing resistance calculator, and a determiner. The toner developing resistance calculator calculates a toner developing resistance on the basis of a bias voltage applied to a developing device and a measured developing current by dividing a value of the bias voltage by a value of the developing current when a developing device develops an electrostatic latent image formed on the surface of an image carrier to form a toner image. The toner charge amount predictor predicts a toner charge amount of a toner which is supplied to the image carrier by the developing device on the basis of a density of the toner image and the developing current. The determiner determines a state of the developing device on the basis of the toner charge amount and the toner developing resistance.
    Type: Application
    Filed: February 2, 2021
    Publication date: August 5, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Kazunori TANAKA, Kanako MORIMOTO, Tamotsu SHIMIZU, Kenichi TAMAKI