Patents by Inventor Masato Yokoyama

Masato Yokoyama 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: 7110700
    Abstract: A belt driving controller includes a driving roller having a radius r1, a plurality of driven rollers that is driven by rotation of the driving roller, the driven rollers having a radius r2, an endless belt that is wound on the driving roller and the driven rollers and an encoder that is attached to one of the driven rollers, and that outputs a signal. The rotation of the driving roller is controlled based on the signal from the encoder, and (?2/?1)×(r1/r2)?1 is satisfied where ?1 is a correction coefficient for a fluctuation in thickness of the endless belt caused by a belt winding angle on the driving roller, and ?2 is a correction coefficient for a fluctuation in the thickness on the driven roller.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: September 19, 2006
    Assignee: Ricoh Company, Limited
    Inventors: Toshiyuki Andoh, Yasumori Nagahara, Tadashi Shinohara, Yuuji Matsuda, Kazuhiko Kobayashi, Nobuto Yokokawa, Masato Yokoyama, Yohhei Miura, Toshiyuki Takahashi, Jun Hosokawa
  • Publication number: 20060182471
    Abstract: A belt driving control apparatus, the belt driving control apparatus having an endless belt, a driving roller driving the endless belt, a driving motor driving the driving roller, at least one idler roller being dependent on the endless belt, and an encoder attached to one of the idler roller, the belt driving control apparatus includes a structure where a control target value of the driving motor is set so that an effective speed of the endless belt is constant and the driving motor is drive-controlled so that the control target value is satisfied.
    Type: Application
    Filed: January 20, 2006
    Publication date: August 17, 2006
    Inventors: Hiroshi Okamura, Yuji Matsuda, Hiromichi Matsuda, Toshiyuki Andoh, Nobuto Yokokawa, Ryoji Imai, Masato Yokoyama, Kazuhiko Kobayashi, Yohei Miura
  • Publication number: 20060165442
    Abstract: A mark detecting unit detects a mark that is a reference position of an endless belt. An angular-displacement-error detecting unit detects an angular displacement error of an encoder caused by thickness fluctuation of the endless belt. A first calculating unit calculates a phase and a maximum amplitude to the mark. A second calculating unit calculates correction data according to a distance from the mark on the endless belt. A belt-drive control device controls a belt driving unit by adding the correction data to a preset control target value to stabilize speed fluctuation of the endless belt due to the thickness fluctuation.
    Type: Application
    Filed: January 19, 2006
    Publication date: July 27, 2006
    Inventors: Kazuhiko Kobayashi, Hiromichi Matsuda, Toshiyuki Andoh, Nobuto Yokokawa, Ryoji Imai, Yuji Matsuda, Hiroshi Okamura, Masato Yokoyama, Yohei Miura
  • Publication number: 20060153604
    Abstract: An image forming apparatus includes a belt stretched across rollers and a resist rotary member that feeds out a recording medium on the belt. A correlation between a velocity of the belt and the resist rotary member is obtained. A target velocity of the belt or the resist rotary member, at which a difference between the velocity when the recording medium is in contact with both the belt and the resist rotary member and the velocity when the recording medium is not in contact with at least either the belt or the resist rotary member is minimum, is determined based on the correlation.
    Type: Application
    Filed: January 9, 2006
    Publication date: July 13, 2006
    Inventors: Hiromichi Matsuda, Toshiyuki Andoh, Masato Yokoyama, Kazuhiko Kobayashi, Yuji Matsuda, Yohei Miura, Hiroshi Okamura, Nobuto Yokokawa, Ryoji Imai
  • Publication number: 20060133873
    Abstract: An endless belt is spanned around at least one driving member and at least one supporting member. The driving member is driven by a pulse motor. An angular displacement of the driving member is detected, a difference between detected angular displacement and a target angular displacement is calculated, a frequency of a driving pulse used to drive the pulse motor is calculated based on the difference and a reference driving pulse frequency, and the pulse motor is controlled based on a driving pulse with calculated frequency. The target angular displacement is set so as to cancel a specific velocity fluctuation component of a surface velocity of the belt produced when the drive member is rotated at a constant angular velocity and that is smaller than amount of surface movement of the belt in one driving pulse.
    Type: Application
    Filed: December 20, 2005
    Publication date: June 22, 2006
    Inventors: Toshiyuki Andoh, Hiromichi Matsuda, Nobuto Yokokawa, Ryoji Imai, Yuji Matsuda, Hiroshi Okamura, Kazuhiko Kobayashi, Yohei Miura, Masato Yokoyama
  • Publication number: 20060110189
    Abstract: To compensate for the variation in the output signal from an encoder due to the variation in the thickness of an endless belt, an apparatus includes: a detector that detects a reference position on the endless belt; a correction-value calculating unit that calculates a correction value for each position on the endless belt based on the thickness; and a target-value calculating unit that adjusts a target value for controlling a driving motor based on the correction value corresponding to a distance from the reference position to the current position.
    Type: Application
    Filed: August 15, 2005
    Publication date: May 25, 2006
    Inventors: Yuji Matsuda, Hiromichi Matsuda, Toshiyuki Andoh, Nobuto Yokokawa, Ryoji Imai, Hiroshi Okamura, Masato Yokoyama, Kazuhiko Kobayashi, Yohei Miura
  • Publication number: 20060087547
    Abstract: An ink jet recording apparatus performs a print operation by controlling an ink jet recording head to eject ink drops there from against front and back surfaces of a recording sheet at a print position. The apparatus includes a transporting mechanism for transporting a portion of the recording sheet to a location outside of the apparatus after a completion of the print operation on the front surface of the recording sheet and just before printing of the back surface of the recording sheet.
    Type: Application
    Filed: December 12, 2005
    Publication date: April 27, 2006
    Inventors: Motokazu Yasui, Tsumori Sato, Masanori Horike, Masato Yokoyama, Masumi Sato
  • Publication number: 20050265737
    Abstract: A passbook printing apparatus comprises a movable tension roller correcting slack of an intermediate transfer film resulting from a different in a feed speed between a film drive roller and a film wind-up reel, and a control device operating the film wind-up reel to apply a predetermined tension to the intermediate transfer material in a state of stopping the film drive roller, thereby moving and fixing the tension roller to a predetermined position, and thereafter, feeding the intermediate transfer film by a predetermined distance by the film drive roller to position it to the transfer position.
    Type: Application
    Filed: May 24, 2005
    Publication date: December 1, 2005
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masato Yokoyama, Toshiaki Aoyagi
  • Patent number: 6949896
    Abstract: A drive control method includes detecting an angular displacement of a rotor driven by a pulse motor, calculating a difference between the detected angular displacement and a preset target value of the angular displacement, and calculating a drive pulse frequency of a drive pulse signal used to drive the pulse motor. The pulse motor is driven by the drive pulse signal having the drive pulse frequency to allow the rotor at a constant angular velocity.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: September 27, 2005
    Assignee: Ricoh Company, Limited
    Inventors: Toshiyuki Andoh, Hiromichi Matsuda, Makoto Komatsu, Tadashi Shinohara, Yuuji Matsuda, Kazuhiko Kobayashi, Nobuto Yokokawa, Masato Yokoyama, Yohhei Miura, Toshiyuki Takahashi, Jun Hosokawa
  • Publication number: 20050085945
    Abstract: A belt driving controller includes a driving roller having a radius r1, a plurality of driven rollers that is driven by rotation of the driving roller, the driven rollers having a radius r2, an endless belt that is wound on the driving roller and the driven rollers and an encoder that is attached to one of the driven rollers, and that outputs a signal. The rotation of the driving roller is controlled based on the signal from the encoder, and (?2/?1)×(r1/r2)?1 is satisfied where ?1 is a correction coefficient for a fluctuation in thickness of the endless belt caused by a belt winding angle on the driving roller, and ?2 is a correction coefficient for a fluctuation in the thickness on the driven roller.
    Type: Application
    Filed: August 27, 2004
    Publication date: April 21, 2005
    Inventors: Toshiyuki Andoh, Yasumori Nagahara, Tadashi Shinohara, Yuuji Matsuda, Kazuhiko Kobayashi, Nobuto Yokokawa, Masato Yokoyama, Yohhei Miura, Toshiyuki Takahashi, Jun Hosokawa
  • Publication number: 20050057209
    Abstract: A method, apparatus, and program for driving a motor in a feedback control system, capable of suppressing oscillation of the motor rotational speed are disclosed. A motor drive controller includes a drive motor, a detector, and a motor drive controller. The drive motor drives a moving body around a target speed. The detector detects a current moving speed of the moving body and outputs it as a detector pulse signal. The controller calculates a difference between the current moving speed and the target moving speed, calculates a control value based on the difference, calculates a pulse rate of a drive pulse signal based on the control value after having controlled the control value to be within a predetermined value, and controls the drive motor based on the pulse rate.
    Type: Application
    Filed: July 19, 2004
    Publication date: March 17, 2005
    Inventors: Toshiyuki Andoh, Tadashi Shinohara, Yuuji Matsuda, Kazuhiko Kobayashi, Nobuto Yokokawa, Masato Yokoyama, Yohhei Miura, Toshiyuki Takahashi, Jun Hosokawa
  • Publication number: 20050053388
    Abstract: An image forming apparatus including an image carrying member, a transfer member, support rollers, a detecting mechanism, and a controller. The image carrying member forms a toner image on its surface facing a surface of the transfer member, supported by the support rollers, which transfers the toner image to a recording medium. The detecting mechanism includes a detection roller, a roller shaft, a moving member, and a sensor, and detects a speed of the transfer member. The detection roller includes one support roller selected from the support rollers, and is provided with the roller shaft. The moving member is directly fixed to the roller shaft and rotates with the detection roller. The sensor detects a moving speed of the detection roller with the moving member. The controller controls a traveling speed of the transfer member to a target speed based on a detection result of the sensor.
    Type: Application
    Filed: July 19, 2004
    Publication date: March 10, 2005
    Inventors: Masato Yokoyama, Nobuto Yokokawa, Toshiyuki Ando, Kazuhiko Kobayashi, Tadashi Shinohara, Yuuji Matsuda, Jun Hosokawa, Yohhei Miura, Toshiyuki Takahashi, Hiromichi Matsuda
  • Publication number: 20050052719
    Abstract: An image forming apparatus includes an image bearing member having a photosensitive surface and an optical writing apparatus generating a laser beam modulated according to image data. The optical writing apparatus includes a housing, an optical deflector, an f-theta lens and a separator. The optical deflector is configured to rotate to deflect the laser beam. The f-theta lens is configured to correct the laser beam deflected by the optical deflector and to transmit a corrected laser beam towards the image bearing member. The separator is configured to separate an inside space of the housing into at least two sections including a first section in which the optical deflector is mounted and a second section in which the f-theta lens is mounted. The separator includes a heat resistant transparent plate disposed at a position of crossing passage of the laser beam between the optical deflector and the f-theta lens.
    Type: Application
    Filed: June 1, 2004
    Publication date: March 10, 2005
    Inventors: Yasumasa Tomita, Hiroshi Yoshizawa, Tetsuya Kimura, Masato Yokoyama, Keiji Okamoto, Keiichi Serizawa
  • Patent number: 6864906
    Abstract: A light scanning device adjusts scanning speed uniformity with high accuracy to obtain an image having fine absolute position accuracy. The light scanning device is mounted on an image forming apparatus. The light scanning device includes a scanning speed uniformity adjusting mechanism that can move a reflection mirror around the axis that is orthogonal to a main scanning corresponding direction and parallel to a reflection surface of the reflection mirror. The light scanning device further includes a scanning line inclination adjusting mechanism that can move an optical element around the axis orthogonal to the main scanning corresponding direction and orthogonal to the sub-scanning corresponding direction. The optical element has a function of adjusting a scanning line position.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: March 8, 2005
    Assignee: Ricoh Company, Ltd.
    Inventor: Masato Yokoyama
  • Publication number: 20040179087
    Abstract: A scanning lens for an optical scanner includes a specific adjusting axis and a curved surface. The specific adjusting axis makes a rotating center of the scanning lens and center of the curved surface. The scanning lens is disposed on a holding member having a receiving surface, so that the curved surface is in contact with the receiving surface. A position of the scanning lens is adjusted by a rotating mechanism that rotates the scanning lens.
    Type: Application
    Filed: February 25, 2004
    Publication date: September 16, 2004
    Inventors: Hiroshi Yoshizawa, Masato Yokoyama
  • Publication number: 20040164691
    Abstract: A drive control method includes detecting an angular displacement of a rotor driven by a pulse motor, calculating a difference between the detected angular displacement and a preset target value of the angular displacement, and calculating a drive pulse frequency of a drive pulse signal used to drive the pulse motor. The pulse motor is driven by the drive pulse signal having the drive pulse frequency to allow the rotor at a constant angular velocity.
    Type: Application
    Filed: December 3, 2003
    Publication date: August 26, 2004
    Inventors: Toshiyuki Andoh, Hiromichi Matsuda, Makoto Komatsu, Tadashi Shinohara, Yuuji Matsuda, Kazuhiko Kobayashi, Nobuto Yokokawa, Masato Yokoyama, Yohhei Miura, Toshiyuki Takahashi, Jun Hosokawa
  • Publication number: 20040165926
    Abstract: An ink jet recording apparatus performs a print operation by controlling an ink jet recording head to eject ink drops there from against front and back surfaces of a recording sheet at a print position. The apparatus includes a transporting mechanism for transporting a portion of the recording sheet to a location outside of the apparatus after a completion of the print operation on the front surface of the recording sheet and just before printing of the back surface of the recording sheet.
    Type: Application
    Filed: February 27, 2004
    Publication date: August 26, 2004
    Inventors: Motokazu Yasui, Tsumori Sato, Masanori Horike, Masato Yokoyama, Masumi Sato
  • Publication number: 20040104993
    Abstract: An optical scanner includes a light source which emits a light beam, a reflection mirror which has a reflection surface, a first axis parallel to a main-scanning direction, and a second axis along the reflection surface and perpendicular to the first axis, and an optical element which adjusts a position of a scanning line in a sub-scanning direction, the optical element having a beam-incidence surface, a third axis parallel to the main-scanning direction on the beam-incidence surface, and a fourth axis perpendicular to the third axis and along a beam-incidence direction. A first adjustment unit is provided to rotate the reflection mirror around the second axis in order to attain uniformity of a scanning speed. A second adjustment unit is provided to rotate the optical element around the fourth axis in order to correct an inclination of the scanning line to a desired position of the scanning line.
    Type: Application
    Filed: September 17, 2003
    Publication date: June 3, 2004
    Inventor: Masato Yokoyama
  • Patent number: 6719469
    Abstract: An ink jet recording apparatus performs a print operation by controlling an ink jet recording head to eject ink drops therefrom against front and back surfaces of a recording sheet at a print position. The apparatus includes a transporting mechanism for transporting a portion of the recording sheet to a location outside of the apparatus after a completion of the print operation on the front surface of the recording sheet and just before printing of the back surface of the recording sheet.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: April 13, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Motokazu Yasui, Tsumori Sato, Masanori Horike, Masato Yokoyama, Masumi Sato
  • Publication number: 20040041992
    Abstract: A light scanning device adjusts scanning speed uniformity with high accuracy to obtain an image having fine absolute position accuracy. The light scanning device is mounted on an image forming apparatus. The light scanning device includes a scanning speed uniformity adjusting mechanism that can move a reflection mirror around the axis that is orthogonal to a main scanning corresponding direction and parallel to a reflection surface of the reflection mirror. The light scanning device further includes a scanning line inclination adjusting mechanism that can move an optical element around the axis orthogonal to the main scanning corresponding direction and orthogonal to the sub-scanning corresponding direction. The optical element has a function of adjusting a scanning line position.
    Type: Application
    Filed: May 13, 2003
    Publication date: March 4, 2004
    Inventor: Masato Yokoyama