Patents by Inventor Hiromitsu Takagaki

Hiromitsu Takagaki 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: 8571452
    Abstract: A transfer and fixing device as means for heating a recording medium prior to transfer and fixing, without risk of fire, superior in energy efficiency, and able to stably heat irrespective of the thickness of the recording medium; and an imaging forming apparatus comprising such a transfer and fixing device comprising: a transfer and fixing member by which an image is transferred; a pressurizing member that forms a nip by pressure contact with the transfer and fixing member and pressurizes and fixes the image on the recording medium that passes through the aforementioned nip; a radiant heat source that is arranged on the upstream side of the nip in the direction of transport of the recording medium; and a thermoconductive member that is heated by the radiant heat source and heats the recording medium when in contact, wherein a radiant heat region is provided, between the nip and the thermoconductive member, where the recording medium is heated by radiant heat from the radiant heat source.
    Type: Grant
    Filed: July 8, 2009
    Date of Patent: October 29, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Seto, Takashi Fujita, Atsushi Nagata, Hiromitsu Takagaki
  • Patent number: 8509675
    Abstract: An image forming apparatus includes an image bearing member to bear an electrostatic latent image on the surface thereof, a transfer-fixing member disposed adjacent to the image baring member, including a transfer surface onto which the toner image is transferred from the image bearing member, a first pressure member to meet and press against the transfer-fixing member to form a nip therebetween, a heating member to heat a recording medium, provided upstream of the nip in a direction of transport of the recording medium, and a transport guide member to change a contact area of the recording medium and the heating member in accordance with a thickness or a resilience of the recording medium. When the recording medium passes the nip, the toner image is pressed and fixed on the recording medium.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: August 13, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Seto, Takashi Fujita, Hiromitsu Takagaki, Atsushi Nagata, Kazuya Saito
  • Patent number: 8483601
    Abstract: A transfer fixing device includes a transfer fixing member, a pressure member, and a primary heater. The transfer fixing member defines a moving surface on which a toner image travels. The pressure member is pressed against the transfer fixing member to define a transfer fixing nip where the toner image traveling along the moving surface meets a surface of a recording medium traveling along the media conveyance path. The primary heater is located upstream of the transfer fixing nip along the media conveyance path to heat the surface of the recording medium before entering the transfer fixing nip. The heated surface of the recording medium fuses toner for transfer and fixing into place at the transfer fixing nip. The pressure member is at least partially electrically biased to generate an electrostatic field to promote transfer of toner at the transfer fixing nip.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: July 9, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuya Saito, Atsushi Nagata, Takashi Fujita, Takashi Seto, Hiromitsu Takagaki
  • Patent number: 8422925
    Abstract: In a transfer-fixing device for transferring and fixing a toner image on a transfer-fixing side of a recording medium, a transfer-fixing member carries the toner image. A pressing member presses against the transfer-fixing member to form a nip between the transfer-fixing member and the pressing member through which the recording medium passes. A heat transmission member is provided upstream from the nip in a recording medium conveyance direction to heat the transfer-fixing side of the recording medium while guiding the recording medium to the nip. A heating member is connected to the heat transmission member to heat the heat transmission member. A biasing member biases the recording medium guided by the heat transmission member against the heat transmission member.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: April 16, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Fujita, Atsushi Nagata, Takashi Seto, Hiromitsu Takagaki, Kazuya Saito, Takeshi Yamamoto
  • Patent number: 8200135
    Abstract: A transfer-fixing device includes a transfer-fixing member, a pressing member, a heating device, and a temperature equalizer. The transfer-fixing member carries the toner image. The pressing member presses against the transfer-fixing member to form a nip portion to which the recording medium is conveyed. The heating device heats the transfer-fixing surface of the recording medium conveyed toward the nip portion. The temperature equalizer equalizes a temperature distribution of a surface of the transfer-fixing member in a width direction of the transfer-fixing member after the surface of the transfer-fixing member passes through the nip portion.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: June 12, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Takeshi Takemoto, Hirohmi Tamura
  • Patent number: 7970325
    Abstract: A transfer fixing member containing a base, and an outermost surface layer composed of an elastic material in which a conductive material is dispersed, wherein when a pressure applied to a surface of the transfer fixing member by making a toner image bearing member in contact with the transfer fixing member upon transferring of a toner image on the toner image bearing member onto the transfer fixing member is 0.2 kg/cm2 to 2.0 kg/cm2, the transfer fixing member has a volume resistance of 106 ?·cm or more to less than 1012 ?·cm, and when a pressure applied to the surface of the transfer fixing member by making the transfer fixing member in contact with the recording medium located between the transfer fixing member and a pressurizing member upon transfer-fixing of the toner image onto the recording medium is 3.0 kg/cm2 to 20 kg/cm2, the transfer fixing is member has a volume resistance of less than 106 ?·cm.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: June 28, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Takashi Fujita, Hiromitsu Takagaki, Takashi Seto, Shin Kayahara, Atsushi Nagata
  • Patent number: 7912412
    Abstract: A transfer-fixing device transfers and fixes a toner image onto a transfer-fixing surface of a recording medium, and includes a transfer-fixing member, a pressing member, a heating member, and a temperature equalization member. The transfer-fixing member carries the toner image. The pressing member pressingly contacts the transfer-fixing member to form a nip between the pressing member and the transfer-fixing member through which the recording medium passes. The heating member heats the transfer-fixing surface of the recording medium conveyed toward the nip so that the recording medium reaches the nip before a temperature of a back surface opposite the transfer-fixing surface of the recording medium increases. The temperature equalization member equalizes temperature distribution on a surface of the transfer-fixing member in a width direction of the transfer-fixing member perpendicular to a conveyance direction of the recording medium, after the surface of the transfer-fixing member passes the nip.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: March 22, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Fujita, Shin Kayahara, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Hirohmi Tamura
  • Patent number: 7907881
    Abstract: The transfer-fixing device includes an image carrier, a pressing member, a heater, and an electrical field generator. The image carrier carries a toner image. The pressing member presses against the image carrier to form a transfer-fixing nip between the pressing member and the image carrier. The heater heats the toner image carried by the image carrier so that a temperature of the toner image is not higher than Tm +10 degrees centigrade when a toner softening point is Tm degrees centigrade. The electrical field generator forms a transfer electrical field at the transfer-fixing nip.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: March 15, 2011
    Assignee: Ricoh Company Limited
    Inventors: Shin Kayahara, Takashi Fujita, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Hirohmi Tamura
  • Patent number: 7869752
    Abstract: A cleaning device including a cleaning member that moves in a predetermined direction and is in contact with a cleaning target that moves in a predetermined direction and which is directly or indirectly heated by a heater, to remove toner particles on a surface of the cleaning target. A contact surface of the cleaning member with the cleaning target includes a plurality of regions of different toner-releasing ability.
    Type: Grant
    Filed: June 23, 2008
    Date of Patent: January 11, 2011
    Assignee: Ricoh Company Limited
    Inventors: Shin Kayahara, Takashi Fujita, Takeshi Takemoto, Hiromitsu Takagaki, Takashi Seto, Kazumi Suzuki, Atsushi Nagata
  • Patent number: 7856201
    Abstract: A transfer fixation apparatus includes: a fixing member that carries the toner image; a pressurizing member that becomes in contact with the fixing member with pressure to form a nip through which the recording target medium is transported; and a plurality of heating members that are provided at relatively upstream positions when viewed from the relatively downstream nip and apply heat to the surface of the recording target medium that is transported toward the nip, wherein the number of heating members that apply heat to the surface of the recording target medium is changed depending on whether the transfer of the toner image is performed only on the front side of the recording target medium or the transfer of the toner image is performed also on the reverse side of the recording target medium after the transfer of the toner image on the front side of the recording target medium.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: December 21, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiromitsu Takagaki, Takashi Fujita, Shin Kayahara, Takashi Seto, Atsushi Nagata, Takeshi Takemoto, Kazumi Suzuki
  • Publication number: 20100239292
    Abstract: In a transfer-fixing device for transferring and fixing a toner image on a transfer-fixing side of a recording medium, a transfer-fixing member carries the toner image. A pressing member presses against the transfer-fixing member to form a nip between the transfer-fixing member and the pressing member through which the recording medium passes. A heat transmission member is provided upstream from the nip in a recording medium conveyance direction to heat the transfer-fixing side of the recording medium while guiding the recording medium to the nip. A heating member is connected to the heat transmission member to heat the heat transmission member. A biasing member biases the recording medium guided by the heat transmission member against the heat transmission member.
    Type: Application
    Filed: March 17, 2010
    Publication date: September 23, 2010
    Inventors: Takashi Fujita, Atsushi Nagata, Takashi Seto, Hiromitsu Takagaki, Kazuya Saito, Takeshi Yamamoto
  • Publication number: 20100232844
    Abstract: A transfer fixing device includes a transfer fixing member, a pressure member, and a primary heater. The transfer fixing member defines a moving surface on which a toner image travels. The pressure member is pressed against the transfer fixing member to define a transfer fixing nip where the toner image traveling along the moving surface meets a surface of a recording medium traveling along the media conveyance path. The primary heater is located upstream of the transfer fixing nip along the media conveyance path to heat the surface of the recording medium before entering the transfer fixing nip. The heated surface of the recording medium fuses toner for transfer and fixing into place at the transfer fixing nip. The pressure member is at least partially electrically biased to generate an electrostatic field to promote transfer of toner at the transfer fixing nip.
    Type: Application
    Filed: March 9, 2010
    Publication date: September 16, 2010
    Inventors: Kazuya Saito, Atsushi Nagata, Takashi Fujita, Takashi Seto, Hiromitsu Takagaki
  • Patent number: 7790343
    Abstract: A process includes developing toner images on a photoconductor, transferring to an intermediate transfer belt and a transferring-and-fixing roller. The toner images are transferred to and fixed to a paper simultaneously while the paper moves between the transferring-and-fixing roller and a pressure roller which is pressed against the transferring-and-fixing roller. After transfer process to the paper, residual toner particles remaining on the transferring-and-fixing roller are removed by a cleaning roller. In order to achieve a cleanability from the transferring-and-fixing roller and prevent the intermediate belt from becoming too high temperature, the elastic modulus of the toner particles measured when the toner particles are heated is greater than the elastic modulus of the toner particles when cooled in a temperature range where the glass transition temperature and 10° C. lower than the melting temperature of the toner particles.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: September 7, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Hiromitsu Takagaki, Takashi Fujita, Atsushi Nakafuji, Hiromi Tamura, Shin Kayahara, Tsuyoshi Sugimoto, Takashi Seto, Katsuaki Miyawaki
  • Patent number: 7711301
    Abstract: An image transfer device provided in an image forming apparatus in which, employing an endless belt as an intermediate transfer member, image transfer is performed at nip positions of a primary transfer portion and secondary transfer portion. Generation of warp in the transferred image resulting from transmission of fluctuations in load and torque of the endless belt generated at the nip position of one transfer portion nip to the nip position of the other transfer portion is prevented. The endless belt is turned between rollers and the endless belt is individually driven at the primary transfer portion and secondary transfer portion by drive sources to generate deflection between the primary transfer portion and the secondary transfer portion.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Takemoto, Takashi Seto, Katsuaki Miyawaki, Takashi Fujita, Hiromitsu Takagaki, Atsushi Nakafuji, Shin Kayahara, Hirohmi Tamura, Kazumi Suzuki
  • Patent number: 7711300
    Abstract: An image forming apparatus includes an image carrier for bearing a visible image thereon, an endless transfer-fixing belt stretchedly disposed between a plurality of spanning members, a pressure member for pressing the transfer-fixing belt to the image carrier while contacting a backside of the transfer-fixing belt at the transfer nip, and a heater for heating the visible image. The visible image on the image carrier is transferred onto the front surface of the transfer-fixing belt at the transfer nip and is transported to the transfer-fixing nip while heated by the heater, where the visible image is transferred and fixed on a recording member. The transfer-fixing belt is stretchedly arranged such that the transfer-fixing belt travels in a direction substantially perpendicular to a pressure direction of the pressure member in the proximity of the transfer nip.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company Ltd.
    Inventors: Atsushi Nakafuji, Takashi Fujita, Shin Kayahara, Hiromitsu Takagaki, Takashi Seto, Katsuaki Miyawaki, Kazumi Suzuki, Hirohmi Tamura
  • Publication number: 20100014897
    Abstract: A transfer and fixing device as means for heating a recording medium prior to transfer and fixing, without risk of fire, superior in energy efficiency, and able to stably heat irrespective of the thickness of the recording medium; and an imaging forming apparatus comprising such a transfer and fixing device comprising: a transfer and fixing member by which an image is transferred; a pressurizing member that forms a nip by pressure contact with the transfer and fixing member and pressurizes and fixes the image on the recording medium that passes through the aforementioned nip; a radiant heat source that is arranged on the upstream side of the nip in the direction of transport of the recording medium; and a thermoconductive member that is heated by the radiant heat source and heats the recording medium when in contact, wherein a radiant heat region is provided, between the nip and the thermoconductive member, where the recording medium is heated by radiant heat from the radiant heat source.
    Type: Application
    Filed: July 8, 2009
    Publication date: January 21, 2010
    Inventors: Takashi Seto, Takashi Fujita, Atsushi Nagata, Hiromitsu Takagaki
  • Publication number: 20100014903
    Abstract: An image forming apparatus includes an image bearing member to bear an electrostatic latent image on the surface thereof, a transfer-fixing member disposed adjacent to the image baring member, including a transfer surface onto which the toner image is transferred from the image bearing member, a first pressure member to meet and press against the transfer-fixing member to form a nip therebetween, a heating member to heat a recording medium, provided upstream of the nip in a direction of transport of the recording medium, and a transport guide member to change a contact area of the recording medium and the heating member in accordance with a thickness or a resilience of the recording medium. When the recording medium passes the nip, the toner image is pressed and fixed on the recording medium.
    Type: Application
    Filed: July 7, 2009
    Publication date: January 21, 2010
    Inventors: Takashi SETO, Takashi Fujita, Hiromitsu Takagaki, Atsushi Nagata, Kazuya Saito
  • Patent number: 7643767
    Abstract: A transfer unit for use in an image forming apparatus includes a transfer belt, and a counter member. The transfer belt, having a given circumferential length, receives an un-fixed image, formed of an image developer, from an image carrier at a first nip, which is defined between the transfer belt and the image carrier. The counter member faces the transfer belt to form a second nip with the transfer belt. The un-fixed image is transferred from the transfer belt to a recording medium passing through the second nip. A slack portion is generated in the transfer belt, when a front edge of the recording medium passes through the second nip. The slack portion of the transfer belt being generated in a first portion of the transfer belt returning from the second nip to the first nip.
    Type: Grant
    Filed: March 2, 2007
    Date of Patent: January 5, 2010
    Assignee: Ricoh Co., Ltd.
    Inventors: Takashi Seto, Takeshi Takemoto, Takashi Fujita, Katsuaki Miyawaki, Hiromitsu Takagaki, Shin Kayahara, Atsushi Nakafuji, Hiromi Tamura, Kazumi Suzuki
  • Patent number: 7613419
    Abstract: An image forming apparatus equipped with an image bearing member, a latent electrostatic image forming unit which forms a latent electrostatic image on the image bearing member, a developing unit which develops the latent electrostatic image by using a toner to form a toner image, a transfer fixing member which is roll shaped or belt shaped and bears the toner image , a heating unit which heats the toner image on the transfer fixing member; and a pressurizing member which is roll shaped and forms a transfer fixing nip with the transfer fixing member. The toner image on the transfer fixing member is transferred and fixed simultaneously to a recording medium which passes through the transfer fixing nip to record an image on the recording medium.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: November 3, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Takashi Fujita, Hideki Kosugi, Ichiro Kadota, Atsushi Nakafuji, Hiromitsu Takagaki
  • Patent number: 7551882
    Abstract: An image forming apparatus includes an image bearing member, a latent electrostatic image forming unit, a developing unit, an intermediate transferring unit which has an intermediate transfer belt and a plurality of rollers supporting the intermediate transfer belt, and a transfer fixing unit. The transfer fixing unit has a transfer fixing belt, a plurality of rollers supporting the transfer fixing belt, a heating member, and a pressurizing member forming a transfer fixing nip with the transfer fixing belt. A first roller, which is one of the plurality of rollers supporting the intermediate transferring belt, is opposite to a second roller, which is one of the plurality of rollers supporting the fixing transfer belt. The first roller and the second roller form a transfer nip between the intermediate transferring belt and the fixing transfer belt. The diameter of the first roller is smaller than the diameter of the second roller.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: June 23, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Seto, Takashi Fujita, Katsuaki Miyawaki, Shin Kayahara, Atsushi Nakafuji, Kazumi Suzuki, Hirohmi Tamura, Hiromitsu Takagaki