Patents by Inventor Masashi Fujishima

Masashi Fujishima 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: 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
  • 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
  • Patent number: 11048192
    Abstract: Provided is an image forming apparatus capable of suppressing the occurrence of image defects in response to a difference in carrier resistance and obtaining high image quality. A developing unit has a developing roller that carries toner in a two-component developer that includes a toner and a magnetic carrier on the surface thereof, and forms a toner image on the surface of a photosensitive drum. A current detecting unit detects developing current flowing between the developing roller and the photosensitive drum when a developing voltage is applied to the developing roller by a developing power supply. When the developing voltage is applied to the photosensitive drum, a control unit derives a carrier resistance based on the developing current detected by a current detecting unit, and controls an AC amplitude of an AC voltage of the developing voltage based on the carrier resistance.
    Type: Grant
    Filed: December 6, 2020
    Date of Patent: June 29, 2021
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Yuji Toyota, Yasuhiro Tauchi, Masashi Fujishima, Norio Kubo, Akira Matayoshi
  • Publication number: 20210173330
    Abstract: Provided is an image forming apparatus capable of suppressing the occurrence of image defects in response to a difference in carrier resistance and obtaining high image quality. A developing unit has a developing roller that carries the toner in a two-component developer that includes a toner and a magnetic carrier on the surface thereof, and forms a toner image on the surface of a photosensitive drum. A current detecting unit detects developing current flowing between the developing roller and the photosensitive drum when a developing voltage is applied to the developing roller by a developing power supply. When the developing voltage is applied to the photosensitive drum, the control unit derives a carrier resistance based on the developing current detected by a current detecting unit, and controls the AC amplitude of the AC voltage of the development voltage is based on the carrier resistance.
    Type: Application
    Filed: December 6, 2020
    Publication date: June 10, 2021
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Yuji TOYOTA, Yasuhiro TAUCHI, Masashi FUJISHIMA, Norio KUBO, Akira MATAYOSHI
  • Patent number: 10345741
    Abstract: A developing device includes a developing container, first and second stirring-conveyance members, a developer carrier, a toner concentration sensor, a scraper, and a scraper attachment unit. The second stirring-conveyance member includes a rotation shaft, a first spiral blade to convey developer in an axial direction, and a second spiral blade to overlap a region where the first spiral blade is formed, which is opposite to the first spiral blade in phase, and lower than the first spiral blade in height in a radial direction. An absent region, where the second spiral blade does not exist, is formed in one pitch of the first spiral blade, the one pitch facing the toner concentration sensor. The scraper attachment unit is formed to extend, along a straight line passing through intersection points of the first and second spiral blades and parallel to the rotation shaft, into the absent region.
    Type: Grant
    Filed: February 7, 2018
    Date of Patent: July 9, 2019
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Masashi Fujishima, Norio Kubo, Junichi Nakagawa, Asami Sasaki
  • Publication number: 20180253033
    Abstract: A developing device includes a developing container, first and second stirring-conveyance members, a developer carrier, a toner concentration sensor, a scraper, and a scraper attachment unit. The second stirring-conveyance member includes a rotation shaft, a first spiral blade to convey developer in an axial direction, and a second spiral blade to overlap a region where the first spiral blade is formed, which is opposite to the first spiral blade in phase, and lower than the first spiral blade in height in a radial direction. An absent region, where the second spiral blade does not exist, is formed in one pitch of the first spiral blade, the one pitch facing the toner concentration sensor. The scraper attachment unit is formed to extend, along a straight line passing through intersection points of the first and second spiral blades and parallel to the rotation shaft, into the absent region.
    Type: Application
    Filed: February 7, 2018
    Publication date: September 6, 2018
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Masashi FUJISHIMA, Norio KUBO, Junichi NAKAGAWA, Asami SASAKI
  • Patent number: 9535356
    Abstract: In the case where development is performed by a two-component developing method, a previous charge removal light-emitting portion applies charge removal light to a first charge removal target region of an effective outer circumferential surface of a photosensitive member on which effective outer circumferential surface an electrostatic latent image can be formed. The first charge removal target region includes a part of a magnetic brush contact region of the effective outer circumferential surface and a region of the effective outer circumferential surface between the magnetic brush contact region and a transfer position of a toner image.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: January 3, 2017
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Shinji Otani, Norio Kubo, Masashi Fujishima, Koji Suenami, Yoshimi Shimizu, Kenichi Tamaki
  • Publication number: 20160161879
    Abstract: In the case where development is performed by a two-component developing method, a previous charge removal light-emitting portion applies charge removal light to a first charge removal target region of an effective outer circumferential surface of a photosensitive member on which effective outer circumferential surface an electrostatic latent image can be formed. The first charge removal target region includes a part of a magnetic brush contact region of the effective outer circumferential surface and a region of the effective outer circumferential surface between the magnetic brush contact region and a transfer position of a toner image.
    Type: Application
    Filed: December 4, 2015
    Publication date: June 9, 2016
    Inventors: Shinji Otani, Norio Kubo, Masashi Fujishima, Koji Suenami, Yoshimi Shimizu, Kenichi Tamaki
  • Patent number: 9304445
    Abstract: A developing roller includes a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier. The roller main body includes an aluminum oxide thin film and a resin coat layer, the aluminum oxide thin film being formed on an outer circumferential surface of a base body that is made of a metal including aluminum, the resin coat layer being formed on a surface of the aluminum oxide thin film that has been subjected to a predetermined heating process, the resin coat layer being made of a resin material and having electric conductivity.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: April 5, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Masashi Fujishima, Yuji Kamiyama, Tamotsu Shimizu, Shizuka Okada, Sakae Saito, Yasuhiro Oishi
  • Patent number: 9298126
    Abstract: A developing device includes a housing, a development roller, and a roller gear. The roller gear is disposed at one axial end of the development roller and transmits a rotational drive force to the development roller. The development roller includes a sleeve and a coating layer. The coating layer is formed by dipping the sleeve in a dipping bath with the sleeve directed axially vertically. The development roller is mounted to the housing such that a lower axial end of the development roller at the time of the dipping is an opposite axial end to the one axial end at which the roller gear is disposed.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: March 29, 2016
    Assignee: KYOCERA Document Solution Inc.
    Inventors: Tamotsu Shimizu, Akihiro Watanabe, Chikara Ishihara, Yasuhiro Tauchi, Masashi Fujishima, Yu Sasaki, Hiroaki Sakai, Yasuhiro Oishi, Yukimasa Watanabe
  • Patent number: 9285713
    Abstract: A developing device supplies a developer to a photosensitive drum, which has a cylindrical shape, and is rotatable around an axis thereof for forming an electrostatic latent image on the circumferential surface thereof. The developing device is provided with a developing roller. The developing roller is disposed to face the photosensitive drum, and has a cylindrical shape. The developing roller is rotatable around an axis thereof for carrying a developer on the circumferential surface thereof. The developing roller is provided with a small diameter portion. The small diameter portion is a part of the circumferential surface of the developing roller. The small diameter portion extends from an axial end of the developing roller axially inward by a predetermined length, and has an outer diameter smaller than an axially middle portion of the developing roller.
    Type: Grant
    Filed: April 7, 2015
    Date of Patent: March 15, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Sakae Saito, Hiroaki Sakai, Yukimasa Watanabe, Yasuhiro Oishi, Masashi Fujishima, Chikara Ishihara, Yasuhiro Tauchi
  • Patent number: 9217951
    Abstract: An image forming apparatus includes an image carrier, a developing device, a bias applying unit, a leakage detecting unit, a bias control unit and a leakage detection control unit. The developing device includes a magnetic roller and a developing roller. The magnetic roller carries a developer layer by being rotated. The developing roller receives the toner from the developer layer and supplies the toner to the image carrier. The leakage detection control unit performs a leakage detecting operation of detecting a value of an inter-peak voltage, at which the leakage occurred. The leakage detection control unit simultaneously starts the leakage detecting operation for a plurality of developing devices and performs the leakage detecting operations of the developing devices in which leakage simultaneously occurred while switching the leakage detecting operations one by one if the leakage simultaneously occurs in a plurality of developing devices at an inter-peak voltage.
    Type: Grant
    Filed: March 10, 2015
    Date of Patent: December 22, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Masashi Fujishima, Yoshinobu Yoneima, Tamotsu Shimizu
  • Patent number: 9201349
    Abstract: Developing device includes developing roller and magnetic roller. Developing roller includes aluminum oxide thin film and resin coat layer. Magnetic roller is disposed to face, without contact, outer circumferential surface of developing roller, and includes aluminum oxide thin film formed on outer circumferential surface of base body that is made of metal including aluminum. Magnetic roller forms toner layer on surface of developing roller via magnetic brush composed of toner and magnetic carrier. AC impedance Z1 is in range from 1.0×105? to 1.0×106? and surface roughness Ra of resin coat layer is in range from 0.057 ?m to 0.280 ?m, AC impedance Z1 being obtained when AC voltage at predetermined frequency is applied to between base body of magnetic roller and base body of developing roller in a state where the magnetic brush is formed on magnetic roller.
    Type: Grant
    Filed: December 15, 2014
    Date of Patent: December 1, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Tamotsu Shimizu, Shizuka Okada, Yuji Kamiyama, Sakae Saito, Yasuhiro Oishi, Masashi Fujishima, Chikara Ishihara
  • Publication number: 20150301473
    Abstract: The present disclosure relates to a developing roller having a conductive support base, a surface of which is covered with a resin layer, wherein the resin layer contains conductive fine particles and soluble nylon serving as a binder resin, and the resin layer surface has a surface roughness Ra of at least 0.4 ?m, a waviness curve cycle of 50 to 400 ?m, and a waviness curve height of 2 to 10 ?m.
    Type: Application
    Filed: April 15, 2015
    Publication date: October 22, 2015
    Inventors: Yukimasa Watanabe, Sakae Saito, Hiroaki Sakai, Yasuhiro Oishi, Masashi Fujishima, Chikara Ishihara, Yasuhiro Tauchi
  • Publication number: 20150293477
    Abstract: A developing device supplies a developer to a photosensitive drum, which has a cylindrical shape, and is rotatable around an axis thereof for forming an electrostatic latent image on the circumferential surface thereof. The developing device is provided with a developing roller. The developing roller is disposed to face the photosensitive drum, and has a cylindrical shape. The developing roller is rotatable around an axis thereof for carrying a developer on the circumferential surface thereof. The developing roller is provided with a small diameter portion. The small diameter portion is a part of the circumferential surface of the developing roller. The small diameter portion extends from an axial end of the developing roller axially inward by a predetermined length, and has an outer diameter smaller than an axially middle portion of the developing roller.
    Type: Application
    Filed: April 7, 2015
    Publication date: October 15, 2015
    Inventors: Sakae Saito, Hiroaki Sakai, Yukimasa Watanabe, Yasuhiro Oishi, Masashi Fujishima, Chikara Ishihara, Yasuhiro Tauchi
  • Publication number: 20150293470
    Abstract: A developing device includes a housing, a development roller, and a roller gear. The roller gear is disposed at one axial end of the development roller and transmits a rotational drive force to the development roller. The development roller includes a sleeve and a coating layer. The coating layer is formed by dipping the sleeve in a dipping bath with the sleeve directed axially vertically. The development roller is mounted to the housing such that a lower axial end of the development roller at the time of the dipping is an opposite axial end to the one axial end at which the roller gear is disposed.
    Type: Application
    Filed: March 27, 2015
    Publication date: October 15, 2015
    Applicant: KYOCERA Document Solutions Inc.
    Inventors: Tamotsu SHIMIZU, Akihiro WATANABE, Chikara ISHIHARA, Yasuhiro TAUCHI, Masashi FUJISHIMA, Yu SASAKI, Hiroaki SAKAI, Yasuhiro OISHI, Yukimasa WATANABE
  • Patent number: 9158227
    Abstract: The present disclosure relates to a developing roller having a conductive support base, a surface of which is covered with a resin layer, wherein the resin layer contains conductive fine particles and soluble nylon serving as a binder resin, and the resin layer surface has a surface roughness Ra of at least 0.4 ?m, a waviness curve cycle of 50 to 400 ?m, and a waviness curve height of 2 to 10 ?m.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: October 13, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Yukimasa Watanabe, Sakae Saito, Hiroaki Sakai, Yasuhiro Oishi, Masashi Fujishima, Chikara Ishihara, Yasuhiro Tauchi
  • Publication number: 20150261127
    Abstract: An image forming apparatus includes an image carrier, a developing device, a bias applying unit, a leakage detecting unit, a bias control unit and a leakage detection control unit. The developing device includes a magnetic roller and a developing roller. The magnetic roller carries a developer layer by being rotated. The developing roller receives the toner from the developer layer and supplies the toner to the image carrier. The leakage detection control unit performs a leakage detecting operation of detecting a value of an inter-peak voltage, at which the leakage occurred. The leakage detection control unit simultaneously starts the leakage detecting operation for a plurality of developing devices and performs the leakage detecting operations of the developing devices in which leakage simultaneously occurred while switching the leakage detecting operations one by one if the leakage simultaneously occurs in a plurality of developing devices at an inter-peak voltage.
    Type: Application
    Filed: March 10, 2015
    Publication date: September 17, 2015
    Inventors: Masashi Fujishima, Yoshinobu Yoneima, Tamotsu Shimizu
  • Patent number: 9122193
    Abstract: A developing roller includes a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier. A resin coat layer has been formed on an outer circumferential surface of the roller main body, the resin coat layer being made of a resin material having electric conductivity. A product of resistance component Rs [?] and electrostatic capacitance component Cs [F] in AC impedance Z of the roller main body is in a range from 2.79×10?7 to 6.77×10?5, the AC impedance Z being obtained when an AC voltage of a predetermined frequency f is applied.
    Type: Grant
    Filed: December 15, 2014
    Date of Patent: September 1, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Yoshinobu Yoneima, Yuji Kamiyama, Akihiro Watanabe, Tamotsu Shimizu, Shizuka Okada, Sakae Saito, Yasuhiro Oishi, Chikara Ishihara, Masashi Fujishima, Yoshimi Shimizu, Yasuhiro Tauchi, Yu Sasaki
  • Publication number: 20150177642
    Abstract: A developing roller includes a roller main body disposed to face, without contact, an outer circumferential surface of an image carrier. A resin coat layer has been formed on an outer circumferential surface of the roller main body, the resin coat layer being made of a resin material having electric conductivity. A product of resistance component Rs [?] and electrostatic capacitance component Cs [F] in AC impedance Z of the roller main body is in a range from 2.79×10?7 to 6.77×10?5, the AC impedance Z being obtained when an AC voltage of a predetermined frequency f is applied.
    Type: Application
    Filed: December 15, 2014
    Publication date: June 25, 2015
    Inventors: Yoshinobu Yoneima, Yuji Kamiyama, Akihiro Watanabe, Tamotsu Shimizu, Shizuka Okada, Sakae Saito, Yasuhiro Oishi, Chikara Ishihara, Masashi Fujishima, Yoshimi Shimizu, Yasuhiro Tauchi, Yu Sasaki