Patents by Inventor Yuuji Wada

Yuuji Wada 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: 10831132
    Abstract: A transfer device includes an intermediate transfer belt configured to bear a toner image and rotate, a transferor configured to contact the intermediate transfer belt via a recording medium and form a transfer nip, a guide configured to guide the recording medium conveyed to the transfer nip, and a pressure reducing device. The intermediate transfer belt is shaped as an endless belt. The pressure reducing device is configured to reduce pressure-contact force of the transferor against the intermediate transfer belt as the recording medium advances in the transfer nip. Therefore, a trailing end of the recording medium does not move toward the intermediate transfer belt when the trailing end of the recording medium has passed the guide.
    Type: Grant
    Filed: January 16, 2019
    Date of Patent: November 10, 2020
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takahiro Suzuki, Yuuji Wada, Naoto Kochi, Shinya Tanaka
  • Publication number: 20190243288
    Abstract: A transfer device includes an intermediate transfer belt configured to bear a toner image and rotate, a transferor configured to contact the intermediate transfer belt via a recording medium and form a transfer nip, a guide configured to guide the recording medium conveyed to the transfer nip, and a pressure reducing device. The intermediate transfer belt is shaped as an endless belt. The pressure reducing device is configured to reduce pressure-contact force of the transferor against the intermediate transfer belt as the recording medium advances in the transfer nip. Therefore, a trailing end of the recording medium does not move toward the intermediate transfer belt when the trailing end of the recording medium has passed the guide.
    Type: Application
    Filed: January 16, 2019
    Publication date: August 8, 2019
    Applicant: Ricoh Company, Ltd.
    Inventors: Takahiro SUZUKI, Yuuji WADA, Naoto KOCHI, Shinya TANAKA
  • Patent number: 10295948
    Abstract: An image forming apparatus including an image bearer, a transfer-bias power source, an environment sensor, and a controller. The controller controls the transfer-bias power source to change the DC component and the AC component, according to the at least one of temperature and humidity detected by the environment sensor and a duty of the transfer bias. The duty is A/(A+B)×100[%] where A denotes an area on a return-directional side to move toner from the recording sheet back to the image bearer, relative to a center value (Voff) of a maximum value and a minimum value of the transfer bias in one cycle of a waveform of the transfer bias, and B denotes an area on a transfer-directional side to move the toner from the image bearer to the recording sheet, relative to the center value (Voff) in the one cycle.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: May 21, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Keigo Nakamura, Hirokazu Ishii, Kenji Sugiura, Takehide Mizutani, Atsushi Nagata, Naoto Kochi, Yuuji Wada, Shinya Tanaka
  • Patent number: 10281848
    Abstract: An improved image forming apparatus includes an image bearer, a nip forming member, a transfer power source, and a controller. The controller switches a transfer mode between a first mode to transfer the toner image onto a first type sheet having a surface smoothness higher than a surface smoothness of a second type sheet and a second mode to transfer the toner image onto the second type sheet. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of greater than or equal to 50% that is a duty on the side of the opposite-peak value in the first mode. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of less than 50%, which is different from the opposite-peak duty of the first mode, in the second mode.
    Type: Grant
    Filed: February 8, 2017
    Date of Patent: May 7, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuuji Wada, Naoto Kochi, Hiroki Nakamatsu, Kazuki Yogosawa, Takahiro Suzuki, Shinya Tanaka, Kenji Sugiura, Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Hirokazu Ishii, Takehide Mizutani, Atsushi Nagata, Keigo Nakamura
  • Patent number: 10228639
    Abstract: An image forming apparatus includes a belt-shaped image bearer, a transferer, a guide, two rotators, and a support. The image bearer has an image bearing surface to bear an image thereon. The transferer forms a transfer section between the transferer and the image bearer, to transfer the image onto a recording medium. The guide is disposed upstream from the transfer section in a delivery direction of the recording medium, to guide the recording medium toward the transfer section. The two rotators are disposed upstream from the transfer section in a moving direction of the image bearer and in contact with a non-image bearing surface of the image bearer opposite to the image bearing surface, a first rotator being closer to the transfer section than a second rotator. The support supports the first rotator and the guide and adjusts a position of the first rotator and a position of the guide.
    Type: Grant
    Filed: May 10, 2017
    Date of Patent: March 12, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Seiichi Kogure, Naohiro Kumagai, Junpei Fujita, Kazuki Yogosawa, Tatsuya Ohsugi, Kenji Sugiura, Yuuji Wada, Takehide Mizutani
  • Patent number: 10185255
    Abstract: An image forming apparatus includes an image bearer to bear a toner image, a nip forming member contacting the image bearer to form a transfer nip, and a transfer power source. The transfer bias has a transfer peak value to electrostatically move toner from the image bearer to the recording sheet and an opposite-peak value to electrostatically move less toner from the image bearer to the recording sheet than the transfer peak value. An opposite-peak duty of the transfer bias is less than 50%. The opposite-peak duty is tr/T×100% where T is one cycle of the transfer bias and tr is a time period during which the transfer bias is on a side of the opposite-peak value relative to an offset voltage of the transfer bias in the one cycle T.
    Type: Grant
    Filed: February 14, 2017
    Date of Patent: January 22, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoto Kochi, Hirokazu Ishii, Seiichi Kogure, Naohiro Kumagai, Kenji Sugiura, Shinya Tanaka, Hiroki Nakamatsu, Yuuji Wada, Junpei Fujita, Takahiro Suzuki, Kazuki Yogosawa, Atsushi Nagata
  • Patent number: 10152001
    Abstract: An image forming apparatus includes an image bearer, an intermediate transferor, a secondary transferor, a plurality of rotators including a secondary driving rotator, and a detector. The image bearer bears a detection image. The detection image is transferred from the image bearer to the intermediate transferor at a primary transfer position. The secondary transferor is looped around the plurality of rotators and disposed in contact with the intermediate transferor at a secondary transfer position where the detection image is transferred from the intermediate transferor to the secondary transferor. The secondary driving rotator drives the secondary transferor. The detector detects the detection image on the secondary transferor at a detection position. With this configuration, a distance from the secondary transfer position to the detection position on the secondary transferor is an integral multiple of a circumference of the secondary driving rotator.
    Type: Grant
    Filed: August 30, 2017
    Date of Patent: December 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Kazuki Yogosawa, Kenji Sugiura, Yuuji Wada
  • Patent number: 10120304
    Abstract: A belt device includes a belt unit including a plurality of rotators and a belt looped around the plurality of rotators. The belt device further includes a frame including a plurality of support portions to support the belt unit, a biasing member to bias the belt unit supported by the frame in a predetermined direction, and an adjuster to adjust a position of at least one of the plurality of support portions.
    Type: Grant
    Filed: August 10, 2017
    Date of Patent: November 6, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Junpei Fujita, Naohiro Kumagai, Seiichi Kogure, Kazuki Yogosawa, Kenji Sugiura, Yuuji Wada
  • Patent number: 10101690
    Abstract: An image forming apparatus includes an image bearer including a first image portion to bear a first toner image, a second image portion to bear a second toner image, and a non-image portion to bear an adjustment pattern. A transferor forms a transfer nip with the image bearer. A controller controls the power source to output an image bias as a transfer bias to transfer the first toner image and the second toner image onto a first recording medium and a second recording medium, respectively, in the transfer nip when the first image portion and the second image portion pass through the transfer nip and output a non-image bias as the transfer bias when the non-image portion passes through the transfer nip. The controller performs a constant current control on the image bias and performs a constant voltage control when the image bias switches to the non-image bias.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: October 16, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenji Sugiura, Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Kazuki Yogosawa, Yuuji Wada, Jyunya Sakuraba
  • Patent number: 10073386
    Abstract: An image forming apparatus including an image bearer; a nip forming member, a nip width changing device, a power source; and a controller. The controller switches between a first mode and a second mode according to a predetermined condition. In the first mode, a duty of the transfer bias is a first duty and a width of a transfer nip is a first width. In the second mode, the duty of the transfer bias is a second duty lower than the first duty and the width of the transfer nip is a second width greater than the first width. The duty is (T?Tt)/T×100% where T denotes one cycle of the transfer bias, and Tt denotes a time period, in which the transfer bias is on a transfer-directional side relative to a time-averaged value of the transfer bias, in the one cycle.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: September 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Naomi Sugimoto, Hirokazu Ishii, Kenji Sugiura, Atsushi Nagata, Takehide Mizutani, Keigo Nakamura, Yuuji Wada, Naoto Kochi, Shinya Tanaka
  • Patent number: 10067454
    Abstract: An image forming apparatus includes an image bearer, an image forming device to form a toner image on the image bearer with toner, a power source to output a bias to transfer the toner image onto a recording medium, and control circuitry. The circuitry controls the power source to decrease a peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when a time-averaged voltage of the bias is on a transfer side of transferring the toner to the recording medium, from a median value of maximum and minimum voltages of the bias. The circuitry controls the power source to increase the peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when the time-averaged voltage of the bias is on a return side of returning the toner to the image bearer, from the median value.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: September 4, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Nagata, Shinya Tanaka, Hirokazu Ishii, Kenji Sugiura, Takehide Mizutani, Keigo Nakamura, Yuuji Wada, Naoto Kochi
  • Patent number: 9897943
    Abstract: A belt unit is detachably attachable to a body of an image forming apparatus. The belt unit includes a belt, a pressing member, and a frame. The belt is wound around a plurality of supports to travel in a belt travel direction. The belt includes a base layer and an elastic layer. The pressing member presses warping on an edge of the belt. The frame supports the plurality of supports. The pressing member is positioned on the frame.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: February 20, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Junpei Fujita, Naohiro Kumagai, Seiichi Kogure, Kazuki Yogosawa, Kenji Sugiura, Yuuji Wada, Yusuke Mitani
  • Publication number: 20180046115
    Abstract: A belt device includes a belt unit including a plurality of rotators and a belt looped around the plurality of rotators. The belt device further includes a frame including a plurality of support portions to support the belt unit, a biasing member to bias the belt unit supported by the frame in a predetermined direction, and an adjuster to adjust a position of at least one of the plurality of support portions.
    Type: Application
    Filed: August 10, 2017
    Publication date: February 15, 2018
    Inventors: Junpei FUJITA, Naohiro KUMAGAI, Seiichi KOGURE, Kazuki YOGOSAWA, Kenji SUGIURA, Yuuji WADA
  • Patent number: 9835987
    Abstract: An image forming apparatus includes an image bearer; a toner image forming device; an intermediate transferor; a primary transfer power source; a secondary transfer nip forming device; and a secondary transfer power source to output a secondary transfer bias. One of two peak values of the secondary transfer bias is a transfer peak value to provide a greater transfer-directional force to move toner from the intermediate transferor toward the recording medium in the secondary transfer nip. An absolute value of the transfer peak value is greater than an absolute value of the primary transfer bias.
    Type: Grant
    Filed: March 9, 2016
    Date of Patent: December 5, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenji Sugiura, Hiroyoshi Haga, Hirokazu Ishii, Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Takehide Mizutani, Yuuji Wada, Naoto Kochi, Tatsuya Ohsugi, Kazuki Yogosawa
  • Publication number: 20170329263
    Abstract: An image forming apparatus includes an image bearer including a first image portion to bear a first toner image, a second image portion to bear a second toner image, and a non-image portion to bear an adjustment pattern. A transferor forms a transfer nip with the image bearer. A controller controls the power source to output an image bias as a transfer bias to transfer the first toner image and the second toner image onto a first recording medium and a second recording medium, respectively, in the transfer nip when the first image portion and the second image portion pass through the transfer nip and output a non-image bias as the transfer bias when the non-image portion passes through the transfer nip. The controller performs a constant current control on the image bias and performs a constant voltage control when the image bias switches to the non-image bias.
    Type: Application
    Filed: May 16, 2017
    Publication date: November 16, 2017
    Inventors: Kenji Sugiura, Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Kazuki Yogosawa, Yuuji Wada, Jyunya Sakuraba
  • Patent number: 9817341
    Abstract: An image forming apparatus includes a plurality of image bearers, a transfer bias member, and a power source. When the transfer bias member transfers a color toner image onto a recording sheet, a second peak value of a peak-to-peak of a transfer bias, which is smaller than a first peak value of the peak-to-peak in an electrostatic force to move toner from the image bearers or an intermediate transfer body to the recording sheet, is zero or has a first polarity to generate the electrostatic force in a transfer direction to move toner from the image bearers or the intermediate transfer body to the recording sheet. When the transfer bias member transfers a monochromatic toner image including only black toner onto the recording sheet, the second peak value is zero or has a second polarity to generate an electrostatic force in an opposite direction to the transfer direction.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: November 14, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Tatsuya Ohsugi, Kenji Sugiura, Hirokazu Ishii, Hiroyoshi Haga, Naohiro Kumagai, Seiichi Kogure, Takehide Mizutani, Junpei Fujita, Yuuji Wada, Kazuki Yogosawa, Naoto Kochi
  • Patent number: 9811036
    Abstract: An endless rotatable belt device including an endless rotatable belt, a scale tape bonded on the belt, at least one optical sensor to detect a scale pattern, and auxiliary tape to cover at least one of the first end and the second end of the scale tape of the belt. The scale tape has a first end and a second end and includes at least one scale pattern. The auxiliary tape has a lower surface friction coefficient than the surface friction coefficient of the scale tape.
    Type: Grant
    Filed: September 19, 2016
    Date of Patent: November 7, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Junpei Fujita, Kenji Sugiura, Yuuji Wada, Hiroyoshi Haga, Seiichi Kogure, Naohiro Kumagai, Kazuki Yogosawa
  • Patent number: 9811046
    Abstract: An image forming apparatus includes a rotatable image bearer, a toner image forming device, a transfer device, a transfer bias power source, and a cleaner. The toner image forming device is to form a toner image on the image bearer. The transfer device contacts a surface of the image bearer to form a transfer nip between the transfer device and the image bearer. The transfer bias power source is to output a transfer bias to transfer the toner image from the image bearer onto a recording medium in the transfer nip. The cleaner is disposed downstream from the transfer nip in a direction of rotation of the image bearer, to electrostatically attract and remove toner from the surface of the image bearer to a surface of the cleaner. The transfer bias includes an alternating current component.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: November 7, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuuji Wada, Naohiro Kumagai, Seiichi Kogure, Junpei Fujita, Kazuki Yogosawa, Kenji Sugirua, Takehide Mizutani, Tatsuya Ohsugi, Hiroyoshi Haga, Hirokazu Ishii
  • Publication number: 20170299987
    Abstract: An image forming apparatus including an image bearer; a nip forming member, a nip width changing device, a power source; and a controller. The controller switches between a first mode and a second mode according to a predetermined condition. In the first mode, a duty of the transfer bias is a first duty and a width of a transfer nip is a first width. In the second mode, the duty of the transfer bias is a second duty lower than the first duty and the width of the transfer nip is a second width greater than the first width. The duty is (T?Tt)/T×100% where T denotes one cycle of the transfer bias, and Tt denotes a time period, in which the transfer bias is on a transfer-directional side relative to a time-averaged value of the transfer bias, in the one cycle.
    Type: Application
    Filed: April 10, 2017
    Publication date: October 19, 2017
    Inventors: Naomi SUGIMOTO, Hirokazu Ishii, Kenji Sugiura, Atsushi Nagata, Takehide Mizutani, Keigo Nakamura, Yuuji Wada, Naoto Kochi, Shinya Tanaka
  • Publication number: 20170300000
    Abstract: An image forming apparatus including an image bearer, a transfer-bias power source, an environment sensor, and a controller. The controller controls the transfer-bias power source to change the DC component and the AC component, according to the at least one of temperature and humidity detected by the environment sensor and a duty of the transfer bias. The duty is A/(A+B)×100[%] where A denotes an area on a return-directional side to move toner from the recording sheet back to the image bearer, relative to a center value (Voff) of a maximum value and a minimum value of the transfer bias in one cycle of a waveform of the transfer bias, and B denotes an area on a transfer-directional side to move the toner from the image bearer to the recording sheet, relative to the center value (Voff) in the one cycle.
    Type: Application
    Filed: April 10, 2017
    Publication date: October 19, 2017
    Inventors: Keigo NAKAMURA, Hirokazu ISHll, Kenji SUGIURA., Takehide MIZUTANI, Atsushi NAGATA, Naoto KOCHI, Yuuji WADA, Shinya TANAKA