Patents by Inventor Masahiro Ashikawa

Masahiro Ashikawa 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: 11803135
    Abstract: A transfer device includes a plurality of photoconductors, a belt, a plurality of primary transfer rollers and control circuitry. The plurality of primary transfer rollers is disposed for the plurality of photoconductors, respectively. The plurality of primary transfer rollers brings the belt into contact with or separate the belt from the plurality of photoconductors. The control circuitry causes at least one of the plurality of primary transfer rollers to press against a corresponding at least one of the plurality of photoconductors to shift a printing mode.
    Type: Grant
    Filed: July 29, 2022
    Date of Patent: October 31, 2023
    Assignee: RICOH COMPANY, LTD.
    Inventors: Nagisa Nakamura, Koji Kiryu, Masahiro Ashikawa, Hiroaki Takagi, Jumpei Yamaguchi, Masashi Kasamai, Kanji Ubukata
  • Patent number: 11789383
    Abstract: An image forming apparatus includes a plurality of image bearers, a plurality of rotation reference position detectors, and circuitry. Each of the plurality of rotation reference position detectors faces a corresponding image bearer of the plurality of image bearers to detect a rotation reference position of the corresponding image bearer. The circuitry performs, before an operation of rotating the plurality of image bearers, alignment control based on a result of detection performed by the plurality of rotation reference position detectors. The alignment control is control of driving of the plurality of image bearers to acquire a given relationship between the respective rotation reference positions of the plurality of image bearers. The circuitry determines whether to perform the alignment control based on whether the operation of rotating the plurality of image bearers is a function maintenance related operation.
    Type: Grant
    Filed: April 28, 2022
    Date of Patent: October 17, 2023
    Assignee: RICOH COMPANY, LTD.
    Inventors: Jumpei Yamaguchi, Koji Kiryu, Masahiro Ashikawa, Masashi Kasamai, Kanji Ubukata, Nagisa Nakamura
  • Publication number: 20230195017
    Abstract: An image forming apparatus includes image bearers, motors, a reference position detector, and processing circuitry. The circuitry senses a density of a toner image on each bearer; forms an image pattern and senses, based on a detection result of the detector and a sensing result of the density, density unevenness in a rotation cycle and a phase of the density unevenness with respect to a rotational position reference of each bearer; calculates a target phase based on the phase sensed; calculates a relative phase difference based on a rotational position and the target phase of each bearer; selects, as a reference image bearer, an image bearer having a minimum phase correction value, based on a calculation result of the difference; and controls the rotational position of each of the other image bearers with respect to the reference image bearer to the phase correction value, with the motors being driven.
    Type: Application
    Filed: November 29, 2022
    Publication date: June 22, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Masashi Kasamai, Koji Kiryu, Masahiro Ashikawa, Jumpei Yamaguchi, Kanji Ubukata, Nagisa Nakamura
  • Publication number: 20230134616
    Abstract: A control device includes circuitry. The circuitry detects density unevenness of a toner image occurring according to a rotation cycle of a plurality of image bearers based on rotation phases and toner image density of the plurality of image bearers, controls rotation phases and rotation speeds of the plurality of image bearers, corrects the rotation phases and the rotation speeds of the plurality of image bearers, controls the rotation speeds of at least two of the plurality of image bearers to be a specified rotation speed, and starts a detection operation of the rotation phases of the plurality of image bearers after a difference between each of the rotation speeds of the at least two of the plurality of image bearers and the specified rotation speed falls within a specified range.
    Type: Application
    Filed: October 13, 2022
    Publication date: May 4, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Kanji Ubukata, Koji Kiryu, Masashi Kasamai, Jumpei Yamaguchi, Masahiro Ashikawa, Nagisa Nakamura
  • Publication number: 20230042229
    Abstract: A transfer device includes a plurality of photoconductors, a belt, a plurality of primary transfer rollers and control circuitry. The plurality of primary transfer rollers is disposed for the plurality of photoconductors, respectively. The plurality of primary transfer rollers brings the belt into contact with or separate the belt from the plurality of photoconductors. The control circuitry causes at least one of the plurality of primary transfer rollers to press against a corresponding at least one of the plurality of photoconductors to shift a printing mode.
    Type: Application
    Filed: July 29, 2022
    Publication date: February 9, 2023
    Inventors: Nagisa NAKAMURA, Koji KIRYU, Masahiro ASHIKAWA, Hiroaki TAKAGI, Jumpei YAMAGUCHI, Masashi KASAMAI, Kanji UBUKATA
  • Publication number: 20220357687
    Abstract: An image forming apparatus includes a plurality of image bearers, a plurality of rotation reference position detectors, and circuitry. Each of the plurality of rotation reference position detectors faces a corresponding image bearer of the plurality of image bearers to detect a rotation reference position of the corresponding image bearer. The circuitry performs, before an operation of rotating the plurality of image bearers, alignment control based on a result of detection performed by the plurality of rotation reference position detectors. The alignment control is control of driving of the plurality of image bearers to acquire a given relationship between the respective rotation reference positions of the plurality of image bearers. The circuitry determines whether to perform the alignment control based on whether the operation of rotating the plurality of image bearers is a function maintenance related operation.
    Type: Application
    Filed: April 28, 2022
    Publication date: November 10, 2022
    Inventors: Jumpei YAMAGUCHI, Koji KIRYU, Masahiro ASHIKAWA, Masashi KASAMAI, Kanji UBUKATA, Nagisa NAKAMURA
  • Patent number: 11256197
    Abstract: An image forming apparatus includes a transferred body to which a toner image is transferred, a transfer device, a contact-separation device, and circuitry. The transfer device transfers the toner image from the transferred body onto a recording medium. The contact-separation device includes a motor and drives the motor to move the transfer device away from or into contact with the transferred body. The circuitry causes the contact-separation device to move the transfer device away from or into contact with the transferred body. The circuitry moves the transfer device away from the transferred body to a first position during standby and locates the transfer device at a second position that is closer to a contact position at which the transfer device is configured to contact the transferred body than the first position in an interval between the recording medium and a succeeding recording medium.
    Type: Grant
    Filed: February 8, 2021
    Date of Patent: February 22, 2022
    Assignee: Ricoh Company, Ltd.
    Inventor: Masahiro Ashikawa
  • Publication number: 20210278785
    Abstract: An image forming apparatus includes a transferred body to which a toner image is transferred, a transfer device, a contact-separation device, and circuitry. The transfer device transfers the toner image from the transferred body onto a recording medium. The contact-separation device includes a motor and drives the motor to move the transfer device away from or into contact with the transferred body. The circuitry causes the contact-separation device to move the transfer device away from or into contact with the transferred body. The circuitry moves the transfer device away from the transferred body to a first position during standby and locates the transfer device at a second position that is closer to a contact position at which the transfer device is configured to contact the transferred body than the first position in an interval between the recording medium and a succeeding recording medium.
    Type: Application
    Filed: February 8, 2021
    Publication date: September 9, 2021
    Applicant: Ricoh Company, Ltd.
    Inventor: Masahiro Ashikawa
  • Patent number: 10322895
    Abstract: A material conveyor, included in a transfer device of an image forming apparatus and configured to use position control of rotary bodies, includes a first rotary body and a second rotary body disposed opposing each other in an opposing region through which a material is conveyable, and a contact and separation device configured to cause at least a surface, of at least one of the first rotary body and the second rotary body to move, between a separated position and a contact position. The contact and separation device is configured to cause the at least the surface to move from the separated position to the contact position, at a first speed, and then to move at a second speed slower than the first speed. A method of position control includes moving at least the surface at different speeds or based on a distance relative to a threshold distance.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: June 18, 2019
    Assignee: RICOH COMPANY, LTD.
    Inventors: Daisuke Momose, Masahiro Ashikawa, Motoharu Takahashi, Yuuya Mizuguchi
  • Publication number: 20180093841
    Abstract: A material conveyor, included in a transfer device of an image forming apparatus and configured to use position control of rotary bodies, includes a first rotary body and a second rotary body disposed opposing each other in an opposing region through which a material is conveyable, and a contact and separation device configured to cause at least a surface, of at least one of the first rotary body and the second rotary body to move, between a separated position and a contact position. The contact and separation device is configured to cause the at least the surface to move from the separated position to the contact position, at a first speed, and then to move at a second speed slower than the first speed. A method of position control includes moving at least the surface at different speeds or based on a distance relative to a threshold distance.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Applicant: Ricoh Company, Ltd.
    Inventors: Daisuke MOMOSE, Masahiro ASHIKAWA, Motoharu TAKAHASHI, Yuuya MIZUGUCHI
  • Patent number: 9419557
    Abstract: A motor control device includes a measuring unit configured to output a measurement value corresponding to a rotation speed of a motor; and a control unit configured to control driving of the motor such that the measurement value makes closer to a target value. When the measurement value does not exceed a predetermined abnormality determination threshold, the control unit controls the driving of the motor based on a difference between the measurement value and the target value. The abnormality determination threshold is set in a positive direction or in a negative direction with reference to the target value. When the measurement value exceeds the abnormality determination threshold, the control unit controls the driving of the motor based on a difference between a corrected measurement value and the target value. The corrected measurement value is set in the same direction as the direction in which the abnormality determination threshold is set.
    Type: Grant
    Filed: April 14, 2014
    Date of Patent: August 16, 2016
    Assignee: Ricoh Company, Ltd.
    Inventor: Masahiro Ashikawa
  • Publication number: 20140306633
    Abstract: A motor control device includes a measuring unit configured to output a measurement value corresponding to a rotation speed of a motor; and a control unit configured to control driving of the motor such that the measurement value makes closer to a target value. When the measurement value does not exceed a predetermined abnormality determination threshold, the control unit controls the driving of the motor based on a difference between the measurement value and the target value. The abnormality determination threshold is set in a positive direction or in a negative direction with reference to the target value. When the measurement value exceeds the abnormality determination threshold, the control unit controls the driving of the motor based on a difference between a corrected measurement value and the target value. The corrected measurement value is set in the same direction as the direction in which the abnormality determination threshold is set.
    Type: Application
    Filed: April 14, 2014
    Publication date: October 16, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventor: Masahiro Ashikawa
  • Patent number: 8660473
    Abstract: An intermediate transfer device including an intermediate transfer body having a primary transfer portion and a secondary transfer portion which bears a secondary image formed by transferring a primary image from an image bearing member; a pair of secondary transfer rollers having a secondary transfer roller and a support roller provided in contact with each other via the intermediate transfer body at the secondary transfer portion, which transfers the secondary image to a recording medium at the secondary transfer portion; a variation detection device that detects an amount of variance occurring to a transfer rotation body when the recording medium is transferred to the secondary transfer portion; and an adjustment device that adjusts the distance between the pair of the secondary transfer rollers according to the amount of variance detected by the variation detection device.
    Type: Grant
    Filed: December 6, 2012
    Date of Patent: February 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Ashikawa, Takahisa Koike, Hideyuki Takayama, Yoshihiro Asano, Minoru Takahashi
  • Patent number: 8639174
    Abstract: A disclosed to-be-transferred object length measurement device includes a first rotating body; a passage detection unit detecting a passage of the to-be-transferred object; a rotation amount measurement unit measuring a rotation amount of the first rotating body in a first measurement period; a second rotating body feeding the to-be-transferred object; a speed detection unit detecting a first feeding speed and a second feeding speed of the to-be-transferred object; and a calculation unit calculating a feeding distance of the to-be-transferred object per a predetermined rotation amount of the first rotating body based on the first feeding speed, and further calculating a length of the to-be-transferred object based on the rotation amount of the first rotating body in the first measurement period, the feeding distance, and the second feeding speed of the to-be-transferred object in the second measurement period.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: January 28, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Ashikawa, Tatsuya Watahiki, Minoru Takahashi, Hideyuki Takayama, Takahisa Koike, Masaru Yamagishi, Takuhei Minami, Takuro Kamiyai, Junya Takigawa, Hiroaki Takagi, Koichi Kudo, Katsuya Kawagoe
  • Patent number: 8590891
    Abstract: A recording medium conveyor includes a first conveyance part conveying a recording medium; a second conveyance part conveying the conveyed recording medium toward a transfer position; a detection part detecting the position of the recording medium conveyed by the second conveyance part; a position error detection part detecting a position error between the transfer position and a position at which there is to be the recording medium when an image reaches the transfer position; a position error storage part storing the detected position errors; a steady-state position error calculation part calculating a steady-state position error from the stored position errors; a first control part controlling the conveyance speed of the first conveyance part to reduce the steady-state position error; and a second control part controlling the conveyance speed of the second conveyance part to reduce the detected position error, with the steady-state position error being reduced.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: November 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Motoharu Takahashi, Yusuke Ishizaki, Masahiro Ashikawa, Minoru Takahashi
  • Publication number: 20130161900
    Abstract: A recording medium conveyor includes a first conveyance part conveying a recording medium; a second conveyance part conveying the conveyed recording medium toward a transfer position; a detection part detecting the position of the recording medium conveyed by the second conveyance part; a position error detection part detecting a position error between the transfer position and a position at which there is to be the recording medium when an image reaches the transfer position; a position error storage part storing the detected position errors; a steady-state position error calculation part calculating a steady-state position error from the stored position errors; a first control part controlling the conveyance speed of the first conveyance part to reduce the steady-state position error; and a second control part controlling the conveyance speed of the second conveyance part to reduce the detected position error, with the steady-state position error being reduced.
    Type: Application
    Filed: December 19, 2012
    Publication date: June 27, 2013
    Applicant: RICOH COMPANY, LTD.
    Inventors: Motoharu TAKAHASHI, Yusuke Ishizaki, Masahiro Ashikawa, Minoru Takahashi
  • Patent number: 8465013
    Abstract: A disclosed carrying apparatus includes a first rotating unit carrying a sheet-like carried medium in a rotating direction, a second rotating unit carrying the carried medium in the rotating direction, a first driving unit rotating the first rotating unit, a second driving unit rotating the second rotating unit, a first rotational speed detecting unit, a second rotational speed detecting unit, a first rotational speed controlling unit, a second rotational speed controlling unit, and a torque information acquiring unit acquiring torque information acting on the first rotating unit, wherein the second rotational speed controlling unit controls the second rotational speed in response to a comparison result between the torque information acquired when the sheet-like carried medium is solely carried by the first rotating unit and the torque information acquired when the sheet-like carried medium is carried by the first rotating unit and the second rotating unit.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: June 18, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Masahiro Ashikawa
  • Publication number: 20130121715
    Abstract: An intermediate transfer device including an intermediate transfer body having a primary transfer portion and a secondary transfer portion which bears a secondary image formed by transferring a primary image from an image bearing member; a pair of secondary transfer rollers having a secondary transfer roller and a support roller provided in contact with each other via the intermediate transfer body at the secondary transfer portion, which transfers the secondary image to a recording medium at the secondary transfer portion; a variation detection device that detects an amount of variance occurring to a transfer rotation body when the recording medium is transferred to the secondary transfer portion; and an adjustment device that adjusts the distance between the pair of the secondary transfer rollers according to the amount of variance detected by the variation detection device.
    Type: Application
    Filed: December 6, 2012
    Publication date: May 16, 2013
    Inventors: Masahiro ASHIKAWA, Takahisa KOIKE, Hideyuki TAKAYAMA, Yoshihiro ASANO, Minoru TAKAHASHI
  • Patent number: 8364064
    Abstract: An intermediate transfer device including an intermediate transfer body having a primary transfer portion and a secondary transfer portion which bears a secondary image formed by transferring a primary image from an image bearing member; a pair of secondary transfer rollers having a secondary transfer roller and a support roller provided in contact with each other via the intermediate transfer body at the secondary transfer portion, which transfers the secondary image to a recording medium at the secondary transfer portion; a variation detection device that detects an amount of variance occurring to a transfer rotation body when the recording medium is transferred to the secondary transfer portion; and an adjustment device that adjusts the distance between the pair of the secondary transfer rollers according to the amount of variance detected by the variation detection device.
    Type: Grant
    Filed: July 29, 2009
    Date of Patent: January 29, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Ashikawa, Takahisa Koike, Hideyuki Takayama, Yoshihiro Asano, Minoru Takahashi
  • Publication number: 20110064496
    Abstract: A disclosed carrying apparatus includes a first rotating unit carrying a sheet-like carried medium in a rotating direction, a second rotating unit carrying the carried medium in the rotating direction, a first driving unit rotating the first rotating unit, a second driving unit rotating the second rotating unit, a first rotational speed detecting unit, a second rotational speed detecting unit, a first rotational speed controlling unit, a second rotational speed controlling unit, and a torque information acquiring unit acquiring torque information acting on the first rotating unit, wherein the second rotational speed controlling unit controls the second rotational speed in response to a comparison result between the torque information acquired when the sheet-like carried medium is solely carried by the first rotating unit and the torque information acquired when the sheet-like carried medium is carried by the first rotating unit and the second rotating unit.
    Type: Application
    Filed: September 7, 2010
    Publication date: March 17, 2011
    Applicant: Ricoh Company, Ltd.
    Inventor: Masahiro Ashikawa