公开(公告)号：US12007712B2

公开(公告)日：2024-06-11

申请号：US18332143

申请日：2023-06-09

Applicant: KYOCERA Document Solutions Inc.

Inventor： Junichi Nakagawa ,  Tamotsu Shimizu ,  Hiroshi Yamazaki ,  Kenichi Tamaki ,  Takuji Watanabe

IPC: G03G21/00 ,  G03G7/00 ,  G03G15/08 ,  G03G21/20

CPC classification number: G03G21/0052 ,  G03G7/0013 ,  G03G15/0808 ,  G03G15/081 ,  G03G15/0889 ,  G03G21/206 ,  G03G2215/085 ,  G03G2221/0021

Abstract: Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. An absolute value of a perpendicular-magnetic-force gradient of a fixed magnet of the developer carrying member is 4.0 mT/° or less at a position where the fixed magnet faces a central portion of the filter in a rotation direction of a developing sleeve.

公开(公告)号：US11630400B2

公开(公告)日：2023-04-18

申请号：US17812097

申请日：2022-07-12

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Yoshihiro Yamagishi ,  Kazunori Tanaka

IPC: G03G15/00 ,  G03G15/06

Abstract: An image forming apparatus includes image forming units. A controller includes an execution section, a measurement section, and a prediction section. The execution section controls execution of a developer refresh operation in which toner is ejected from a developer bearing member to an image bearing member so that a specific image forming unit replenishes a development device with the toner from the developer bearing member. The measurement section measures respective surface potentials of the image bearing members included in other image forming units while the specific image forming unit is executing the developer refresh operation. The prediction section uses measurement results of the respective surface potentials of the image bearing members included in the other image forming units for a prediction on the surface potential of the image bearing member included in the specific image forming unit.

公开(公告)号：US20210302867A1

公开(公告)日：2021-09-30

申请号：US17206261

申请日：2021-03-19

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Norio Kubo ,  Asami Sasaki ,  Yasuhiro Tauchi ,  Yuji Toyota

IPC: G03G15/06

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.

公开(公告)号：US11131943B1

公开(公告)日：2021-09-28

申请号：US17210395

申请日：2021-03-23

Applicant: KYOCERA Document Solutions Inc.

Inventor： Kazunori Tanaka ,  Yoshihiro Yamagishi ,  Tamotsu Shimizu

IPC: G03G15/06

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.

公开(公告)号：US11112732B1

公开(公告)日：2021-09-07

申请号：US17171357

申请日：2021-02-09

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Yasuhiro Tauchi ,  Akira Matayoshi ,  Masashi Fujishima

IPC: G03G15/09 ,  G03G15/16 ,  G03G15/08 ,  G03G15/02

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 expression and the second approximation expression intersect each other.

公开(公告)号：US11112722B1

公开(公告)日：2021-09-07

申请号：US17206248

申请日：2021-03-19

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Norio Kubo ,  Asami Sasaki ,  Yasuhiro Tauchi ,  Yuji Toyota

IPC: G03G15/06

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.

公开(公告)号：US20210149321A1

公开(公告)日：2021-05-20

申请号：US17098406

申请日：2020-11-15

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Mitsuhiro Hashimoto ,  Takahiro Okubo ,  Yohei Wakasa ,  Kazuhiro Nakachi

IPC: G03G15/06

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.

公开(公告)号：US10996585B2

公开(公告)日：2021-05-04

申请号：US16985151

申请日：2020-08-04

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Mitsuhiro Hashimoto ,  Takahiro Okubo ,  Kazuhiro Nakachi ,  Shiro Kaneko

IPC: G03G15/06 ,  G03G15/08

Abstract: An image forming apparatus includes an image forming portion, a high-voltage generation circuit, a current detection portion and a control portion. The image forming portion includes an image carrying member, a charging device, an exposure device and a developing device which includes a developer carrying member for carrying a developer including a carrier and a toner. The control portion can perform a development ghost prediction mode that includes a step of measuring the amount of charge of the toner within the developing device at the time of non-image formation, a step of measuring, as a carrier current, the direct-current component of a development current when the amount of development of the toner is 0 [mg/cm2] and a step of estimating the level of occurrence of development ghost and the cause of occurrence based on the amount of charge of the toner and the carrier current which are measured.

公开(公告)号：US10698337B2

公开(公告)日：2020-06-30

申请号：US16424674

申请日：2019-05-29

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Akifumi Yamaguchi ,  Yasuhiro Tauchi ,  Eiji Gyotoku ,  Yu Sasaki

IPC: G03G15/06 ,  G03G15/08 ,  G03G15/00

Abstract: An image forming apparatus includes a developer information acquisition unit. The developer information acquisition unit performs a developer deterioration information acquisition operation. In the developer deterioration information acquisition operation, the developer information acquisition unit acquires a tilt of a measurement straight line representing the relationship between the change amount of the frequency in a first measurement toner image forming operation and the density change amount of the measurement toner image based on the change amount of the frequency in the first measurement toner image forming operation and a result of detecting density of the measurement toner image in a density detecting unit, and acquires a toner charging amount based on the acquired tilt of the measurement straight line and the reference information in the storage unit so as to acquire information relating to deterioration of developer based on the acquired toner charging amount.

公开(公告)号：US20190369522A1

公开(公告)日：2019-12-05

申请号：US16424566

申请日：2019-05-29

Applicant: KYOCERA Document Solutions Inc.

Inventor： Tamotsu Shimizu ,  Yasushi Imanishi

IPC: G03G15/06

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias with the potential difference in the direct current voltage between the developing roller and the image carrier being kept constant, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and the density change amount of the measurement toner image, based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires a charging amount of the toner included in the measurement toner image formed on the image carrier based on the acquired tilt of the measurement straight line and the reference information in the storage unit according to the toner density detected by the toner density detecting unit.