Patents by Inventor Yasuhiro Maehata
Yasuhiro Maehata 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).
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Publication number: 20110058827Abstract: A main controlling part is configured to choose and execute either a constant belt speed control which controls a driving motor (a driving source for an intermediate transfer belt) to move the intermediate transfer belt at a predetermined target belt speed or a constant motor speed control which rotates the driving motor at a predetermined target rotational speed according to a print command, and then, prior to a first-time print job, after executing a writing position correcting process while moving the intermediate transfer belt under the constant belt speed control, forms a color shift detecting image by switching from the constant belt speed control to the constant motor speed control, measures a difference between amounts of color shift, and executes a speed correcting process for correcting the target rotational speed of the driving motor in the constant motor speed control based on the measurement result.Type: ApplicationFiled: September 3, 2010Publication date: March 10, 2011Applicant: Ricoh Company, Ltd.Inventors: Yasuhiro Maehata, Yasuhisa Ehara, Noriaki Funamoto, Tetsuji Nishikawa, Jun Yasuda, Hiroaki Murakami
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Publication number: 20110058870Abstract: A sheet conveyance device for conveying a recording medium includes a fixed roller, a movable roller, an urging member, and a shock absorber, and an image forming apparatus including the sheet conveyance device. The position of the fixed roller is fixed. The movable roller is disposed opposite the fixed roller to contact the fixed roller, thereby defining a nip. The urging member urges the movable member to contact the fixed roller in the absence of the recording medium in the nip and allows the movable member to separate from the fixed roller by an amount corresponding to a thickness of a recording medium when the recording medium enters the nip. The shock absorber absorbs displacement energy generated when the urging member urges the movable roller to contact the fixed roller again after the recording medium passes through the nip.Type: ApplicationFiled: September 2, 2010Publication date: March 10, 2011Inventors: Hiroaki Murakami, Yasuhisa Ehara, Noriaki Funamoto, Tetsuji Nishikawa, Yasuhiro Maehata, Jun Yasuda, Satoshi Araaki
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Publication number: 20110044724Abstract: An image forming apparatus includes an endless belt member; a drive unit moving the endless belt member; a first detecting unit detecting a rotating speed of the drive unit; a second detecting unit detecting an endless transport speed of the endless belt member; and a control unit controlling the rotating speed of the drive unit based on a first detection signal from the first detecting unit or a second detection signal from the second detecting unit selectively depending on a selection condition. Upon selection of the first detection signal in accordance with the selection condition, the control unit corrects the rotating speed of the drive unit using the second detection signal such that an average value of the endless transport speed of the endless belt member approaches a target average value.Type: ApplicationFiled: July 28, 2010Publication date: February 24, 2011Applicant: Ricoh Company, Ltd.Inventors: Noriaki Funamoto, Yasuhisa Ehara, Tetsuji Nishikawa, Yasuhiro Maehata, Jun Yasuda
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Patent number: 7860442Abstract: An image fixing device for use in an image forming apparatus. The fixing device includes a fixing member which fixes a toner image on a recording medium at a nip area, a pressurizing member which pressures the recording medium toward the fixing member at the nip area, a carbon lamp which emits infrared rays, and a reflecting member which reflects the infrared rays to the nip area.Type: GrantFiled: July 3, 2007Date of Patent: December 28, 2010Assignee: Ricoh Company, Ltd.Inventors: Tetsuji Nishikawa, Takayuki Niihara, Kazuki Suzuki, Kazunori Bannai, Makoto Kikura, Yasuhiro Maehata
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Publication number: 20100303504Abstract: A multicolor imaging system includes a controller which adjusts a phase difference in rotations of photoreceptors based on information detected by a rotary position detector, and drive elements for photoreceptors which generate a velocity fluctuation in the same cycle as that of a transfer unit. The controller is configured to concurrently adjust the phases of the photoreceptors and those of the drive elements so that a registration error in four color toner image on an intermediate transfer belt is reduced to a minimum.Type: ApplicationFiled: May 28, 2010Publication date: December 2, 2010Inventors: Noriaki Funamoto, Yasuhisa Ehara, Tetsuji Nishikawa, Yasuhiro Maehata, Jun Yasuda, Hiroaki Murakami
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Publication number: 20100239318Abstract: A printer according to the present invention is a so-called tandem-type printer, and has a configuration that a motor gear is directly connected to an M-photoconductor driving gear and an idler gear is directly connected to a Y-photoconductor driving gear and the M-photoconductor driving gear. A diameter of the Y and M photoconductors driving gear, a distance between transfer sections of the Y and M photoconductors, a motor gear input angle, and an idler input angle are set so that an absolute value of a value obtained by subtracting 1 from an ideal amplitude ratio, which indicates a ratio of an ideal amplitude of an eccentric component of the Y-photoconductor driving gear to an actual amplitude of an eccentric component of the M-photoconductor driving gear, is equal to or less than a maximum allowable amplitude ratio.Type: ApplicationFiled: March 16, 2010Publication date: September 23, 2010Inventors: Yasuhiro Maehata, Tetsuji Nishikawa, Masahiro Ishida, Yasuhisa Ehara, Noriaki Funamoto, Jun Yasuda
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Publication number: 20100226676Abstract: In an image forming apparatus, a servomotor is used as a shared driving motor. A motor driver includes a gain changing unit that changes proportional gain. When a monochrome mode is selected, a driving control unit sets the proportional gain lower than a value that is set in a color mode.Type: ApplicationFiled: February 25, 2010Publication date: September 9, 2010Inventors: Noriaki Funamoto, Yasuhisa Ehara, Tetsuji Nishikawa, Yasuhiro Maehata, Jun Yasuda
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Publication number: 20100183322Abstract: In an image forming apparatus, a rotation detector detects an angular velocity or an angular displacement of a shared drive motor, or an angular velocity or an angular displacement of a photosensitive element. A drive control unit executes a process for controlling a drive speed of a drive source of the photosensitive element based on a result of detection by the rotation detector.Type: ApplicationFiled: December 30, 2009Publication date: July 22, 2010Inventors: Noriaki Funamoto, Yasuhisa Ehara, Tetsuji Nishikawa, Yasuhiro Maehata, Jun Yasuda
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Patent number: 7706723Abstract: An image forming apparatus includes a plurality of image carriers, a drive mechanism, a plurality of drive force transmission gears, a phase difference detector, and a shift unit. The plurality of image carriers forms images of separate colors. The drive mechanism including a single drive unit for driving the plurality of image carriers simultaneously. The plurality of drive force transmission gears, provided for each of the image carriers, transmits a driving force from the drive unit to the image carriers. The phase difference detector detects a phase difference in drive speed among the image carriers. The shift unit, provided for each of the plurality of drive force transmission gears, meshes or unmeshes the drive force transmission gear to the drive mechanism. The shift unit is activated to correct any phase difference in drive speed of the image carriers based on a detection result detected with the phase difference detector.Type: GrantFiled: October 12, 2007Date of Patent: April 27, 2010Assignee: Ricoh Company, Ltd.Inventors: Masahiro Ishida, Kazuki Suzuki, Tetsuji Nishikawa, Yasuhiro Maehata, Takayuki Niihara, Makoto Kikura
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Patent number: 7702252Abstract: A connector connects a rotatable body including an attachment hole and an engaging groove, and a shaft pressed into the attachment hole to integrally rotate. The connector includes at least one pin configured to fit in the engaging groove; and a screw having a head configured to be pressed against the rotatable body either directly or via another member. The at least one pin is fixed on the shaft and extends in a radial direction of the shaft to penetrate the shaft. The screw is screwed into a screw hole on an end face of the shaft and is tightened to press the at least one pin against a surface of the engaging groove.Type: GrantFiled: July 2, 2007Date of Patent: April 20, 2010Assignee: Ricoh Company, LimitedInventors: Yasuhiro Maehata, Kazuki Suzuki, Takayuki Niihara, Makoto Kikura, Tetsuji Nishikawa, Masahiro Ishida
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Publication number: 20090317109Abstract: A driving motor for a color black is shared between a photosensitive body for the color black and a driving roller that drives an intermediate transfer belt not shown. Furthermore, a driving motor for colors yellow, magenta, and cyan is shared between photosensitive bodies for the colors yellow, magenta, and cyan. Driving of the driving motor for the colors yellow, magenta, and cyan is controlled based on a first waveform as a speed fluctuation waveform of the photosensitive body for the color black obtained when the driving motor for the color black is driven at a predetermined speed and second waveforms as speed fluctuation waveforms of the photosensitive bodies for the colors yellow, magenta, and cyan obtained when the driving motor for the colors yellow, magenta, and cyan is driven at a predetermined speed.Type: ApplicationFiled: June 19, 2009Publication date: December 24, 2009Inventors: Yasuhisa Ehara, Noriaki Funamoto, Jun Yasuda, Tetsuji Nishikawa, Yasuhiro Maehata
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Publication number: 20080282839Abstract: A driving device includes a shaft member and a driven gear rotatably disposed to the shaft member that is formed to be fixed to a surface plate member inside the driving device. The shaft member is provided with a flow passage for air penetrating along a shaft line thereof. A cavity is formed in a bearing member of the driven gear to be spaced from the shaft member.Type: ApplicationFiled: April 17, 2008Publication date: November 20, 2008Inventors: Kazuki Suzuki, Yasuhiro Maehata
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Publication number: 20080260420Abstract: An image forming apparatus that includes at least one process cartridge having a photosensitive element, a development unit, a toner storage unit, a driven shaft and a driven gear mounted thereon and which is detachably attachable to the apparatus from a top front side thereof, a drive shaft, a drive gear mounted on the drive shaft to couple with and drive the driven gear to transmit a driving force to the process cartridge, an upper cover opening and closing with respect to the apparatus, a front cover opening and closing with respect to the apparatus, and at least one block component to block coupling of the drive gear and the driven gear by contacting the driven shaft while interlocked with opening and closing of the upper cover. The process cartridge is detachably attachable to the apparatus from the front top side thereof by opening and closing the upper cover.Type: ApplicationFiled: April 18, 2008Publication date: October 23, 2008Inventors: Yasuhiro Maehata, Makoto Kikura, Tetsuji Nishikawa
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Publication number: 20080124152Abstract: An image fixing device for use in an image forming apparatus. The fixing device includes a fixing member which fixes a toner image on a recording medium at a nip area, a pressurizing member which pressures the recording medium toward the fixing member at the nip area, a carbon lamp which emits infrared rays, and a reflecting member which reflects the infrared rays to the nip area.Type: ApplicationFiled: July 3, 2007Publication date: May 29, 2008Inventors: Tetsuji Nishikawa, Takayuki Niihara, Kazuki Suzuki, Kazunori Bannai, Makoto Kikura, Yasuhiro Maehata
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Publication number: 20080089713Abstract: An image forming apparatus includes a plurality of image carriers, a drive mechanism, a plurality of drive force transmission gears, a phase difference detector, and a shift unit. The plurality of image carriers forms images of separate colors. The drive mechanism including a single drive unit for driving the plurality of image carriers simultaneously. The plurality of drive force transmission gears, provided for each of the image carriers, transmits a driving force from the drive unit to the image carriers. The phase difference detector detects a phase difference in drive speed among the image carriers. The shift unit, provided for each of the plurality of drive force transmission gears, meshes or unmeshes the drive force transmission gear to the drive mechanism. The shift unit is activated to correct any phase difference in drive speed of the image carriers based on a detection result detected with the phase difference detector.Type: ApplicationFiled: October 12, 2007Publication date: April 17, 2008Inventors: Masahiro Ishida, Kazuki Suzuki, Tetsuji Nishikawa, Yasuhiro Maehata, Takayuki Niihara, Makoto Kikura
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Publication number: 20080069635Abstract: A connector connects a rotatable body including an attachment hole and an engaging groove, and a shaft pressed into the attachment hole to integrally rotate. The connector includes at least one pin configured to fit in the engaging groove; and a screw having a head configured to be pressed against the rotatable body either directly or via another member. The at least one pin is fixed on the shaft and extends in a radial direction of the shaft to penetrate the shaft. The screw is screwed into a screw hole on an end face of the shaft and is tightened to press the at least one pin against a surface of the engaging groove.Type: ApplicationFiled: July 2, 2007Publication date: March 20, 2008Inventors: Yasuhiro Maehata, Kazuki Suzuki, Takayuki Niihara, Makoto Kikura, Tetsuji Nishikawa, Masahiro Ishida