Patents by Inventor Eisaku Murakami

Eisaku Murakami 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: 8180270
    Abstract: An image forming apparatus includes a fixing unit and a re-heating unit. The fixing unit fixes a toner image on a recording medium by applying heat to the toner image with a first glossiness level. The re-heating unit re-heats the toner image, fixed on the recording medium by the fixing unit, to set a second glossiness level lower than the first glossiness level.
    Type: Grant
    Filed: June 23, 2008
    Date of Patent: May 15, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Kei Yasutomi, Hitoshi Maruyama, Masanori Saitoh, Takeo Tsukamoto, Katsuhiro Aoki, Katsuaki Miyawaki, Eisaku Murakami
  • Patent number: 7925188
    Abstract: A novel development device includes a developer roller, a developer reservoir, a rotatable conveyor, and a replenisher unit. The developer roller is configured to supply toner particles to the electrostatic latent image. The developer reservoir is configured to hold the developer therewithin for application to the developer roller. The rotatable conveyor is configured to rotate within the developer reservoir to convey the developer toward the developer roller. The replenisher unit has a tubular member terminating at a port opening in the developer reservoir. The replenisher unit is configured to direct a particulate material through the tubular member into the developer reservoir via the port. The particulate material is toner particles, carrier particles, or a mixture of toner particles and a given amount of carrier particles. The port is submerged in the developer within the developer reservoir as the rotatable conveyor rotates.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: April 12, 2011
    Assignee: Ricoh Company Limited
    Inventors: Tetsuya Senoh, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Kenichi Taguma, Shunichi Hashimoto
  • Patent number: 7672605
    Abstract: A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.
    Type: Grant
    Filed: June 6, 2007
    Date of Patent: March 2, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Shin Kayahara, Yoshiyuki Kimura, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Eiji Shimojo, Shunichi Hashimoto
  • Patent number: 7657218
    Abstract: A disclosed gloss-providing sheet for providing high gloss to a toner image on a recording material by being placed on a toner image surface of the recording material, heated so as to fuse toner, and then separated from the recording material after the toner is cooled and solidified includes: a notification portion that changes a visual state thereof when a temperature of the gloss-providing sheet becomes equal to or lower than a glass transition temperature of the toner.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: February 2, 2010
    Assignee: Ricoh Company Ltd.
    Inventors: Hitoshi Maruyama, Kei Yasutomi, Eisaku Murakami, Reki Nakamura
  • Patent number: 7630659
    Abstract: A method and an apparatus of controlling a charge voltage including the steps of applying, charging, detecting, and determining. The applying step applies an application voltage having a direct-current voltage and an alternating-current voltage superimposed onto the direct-current voltage to a charge-applying member to charge a charge carrier. The changing step charges the alternating-current voltage of the application voltage. The detecting step detects an alternating current flowing through the charge carrier when the charge-applying member applies the application voltage to the charge carrier. The determining step determines a value of the alternating-current voltage of the application voltage based on at least two alternating currents detected by the alternating-current detector.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: December 8, 2009
    Assignee: Ricoh Co., Ltd.
    Inventors: Takeshi Uchitani, Eisaku Murakami, Yoshiyuki Kimura, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Eiji Shimojo, Shunichi Hashimoto, Shin Kayahara
  • Patent number: 7603062
    Abstract: A conductive member, including a long conductive supporting body, an electrical resistance adjusting layer, disposed on the outer circumferential surface of the conductive supporting body and having a reduced diameter section at either end, and a pair of gap maintaining members which are respectively fitted onto said reduced diameter sections of the electrical resistance adjusting layer. The outer circumferential surfaces of the gap maintaining members have a height differential with respect to the outer circumferential surface of the electrical resistance adjusting layer, in such a manner that when abutted against an image carrier, a prescribed gap is formed between the outer circumferential surface of the image carrier and the outer circumferential surface of the electrical resistance adjusting layer. An interval between the end faces of the electrical resistance adjusting layer and the faces of the gap maintaining members opposing the end faces satisfies a predetermined relationship.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: October 13, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Eiji Shimojo, Masanori Kawasumi, Yoshiyuki Kimura, Masahiko Satoh, Takeshi Uchitani, Hideki Zemba, Yutaka Narita, Shunichi Hashimoto, Eisaku Murakami, Shin Kayahara
  • Patent number: 7555243
    Abstract: A charging member, which can be provided in a process cartridge and/or in an image forming apparatus, includes a conductive supporting member, an electrical resistance control layer formed on an outer circumferential surface of the conductive supporting member, and a nonconductive gap retaining member configured to retain a gap between the conductive supporting member and an image carrying member closely disposed to each other to have a constant distance. At least a portion of the nonconductive gap retaining member is mounted on the electrical resistance control layer at both ends of the conductive supporting member, and a circumference of the nonconductive gap retaining member projects from the electrical resistance control layer. An amount of projection of the gap retaining member from the electrical resistance control layer decreases as the gap retaining member tapers in a direction toward a center of an image formation region.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: June 30, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiko Satoh, Masanori Kawasumi, Yoshiyuki Kimura, Eisaku Murakami, Hideki Zemba, Takeshi Uchitani, Shin Kayahara, Shunichi Hashimoto, Eiji Shimojo
  • Patent number: 7493075
    Abstract: A cleaning device, a process cartridge, and an image forming apparatus including an antifriction agent coating part and a toner removing part. The antifriction agent coating part coats a solid antifriction agent on the surface of an image support body, and is disposed in an upstream side from a cleaning blade with respect to a rotational direction of the image support body. The toner removing part removes toner particles, and is disposed in an upstream side from the antifriction agent coating part with respect to the rotational direction of the image support body and a portion of the toner removing part is positioned below a portion of the antifriction agent coating part in a vertical direction perpendicular to the ground.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: February 17, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeshi Shintani, Takuji Yoneda, Toshio Koike, Masato Yanagida, Naohiro Kumagai, Hiroyuki Nagashima, Atsuhsi Sampe, Eisaku Murakami, Masanori Kawasumi, Takeshi Uchitani, Masami Tomita
  • Publication number: 20090003904
    Abstract: An image forming apparatus includes a fixing unit and a re-heating unit. The fixing unit fixes a toner image on a recording medium by applying heat to the toner image with a first glossiness level. The re-heating unit re-heats the toner image, fixed on the recording medium by the fixing unit, to set a second glossiness level lower than the first glossiness level.
    Type: Application
    Filed: June 23, 2008
    Publication date: January 1, 2009
    Inventors: Kei YASUTOMI, Hitoshi Maruyama, Masanori Saitoh, Takeo Tsukamoto, Katsuhiro Aoki, Katsuaki Miyawaki, Eisaku Murakami
  • Patent number: 7430377
    Abstract: An image forming apparatus includes an image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms a latent image on the image carrier, a developing unit that develops the latent image to form a toner image, a transferring unit that transfers the toner image to a recording medium, a cleaning unit that cleans toner remaining on the image carrier, a lubricant applying unit that applies a solid lubricant to a surface of the image carrier, and a detecting unit that detects whether the image carrier is brand new. The toner has an average roundness of 0.94 or more. The lubricant applying unit is operated when the detecting unit detects that the image carrier is brand new.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: September 30, 2008
    Assignee: Ricoh Company, Limited
    Inventors: Toshio Koike, Ken Amemiya, Naohiro Kumagai, Masato Yanagida, Masanori Kawasumi, Takeshi Uchitani, Yutaka Takahashi, Yuji Arai, Takaaki Tawada, Masami Tomita, Takeshi Tabuchi, Eisaku Murakami, Takeshi Shintani, Takuji Yoneda
  • Publication number: 20080226311
    Abstract: A novel development device includes a developer roller, a developer reservoir, a rotatable conveyor, and a replenisher unit. The developer roller is configured to supply toner particles to the electrostatic latent image. The developer reservoir is configured to hold the developer therewithin for application to the developer roller. The rotatable conveyor is configured to rotate within the developer reservoir to convey the developer toward the developer roller. The replenisher unit has a tubular member terminating at a port opening in the developer reservoir. The replenisher unit is configured to direct a particulate material through the tubular member into the developer reservoir via the port. The particulate material is toner particles, carrier particles, or a mixture of toner particles and a given amount of carrier particles. The port is submerged in the developer within the developer reservoir as the rotatable conveyor rotates.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 18, 2008
    Inventors: Tetsuya Senoh, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Kenichi Taguma, Shunichi Hashimoto
  • Patent number: 7400844
    Abstract: An image forming apparatus including a latent image bearing member, a charger, a latent image forming device, a developing device, a surface moving member, a transfer device, a cleaner having a cleaning blade and an irradiating device configured to discharge the latent image bearing member. This developing device is configured to develop images with a toner having a circularity not less than 0.94. The irradiating device is disposed on the upstream from the cleaner relative to the rotation direction of the latent image bearing member.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: July 15, 2008
    Assignee: Ricoh Company Limited
    Inventors: Eisaku Murakami, Hiroyuki Nagashima, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Toshio Koike, Atsushi Sampe, Masanori Kawasumi, Masami Tomita, Takeshi Uchitani
  • Patent number: 7386257
    Abstract: An imaging apparatus that is capable of realizing good cleaning characteristics and transfer characteristics, and obtaining a high quality image using toner having a high average roundness is provided. The imaging apparatus includes an image carrier, a charge unit, a developing unit, a transfer unit, and a cleaning unit. The transfer unit may directly transfer a toner image onto a recording medium that is carried by a transfer belt, or transfer the toner image onto the transfer belt first to then transfer the toner image onto the recording medium from the transfer belt. The cleaning unit includes a cleaning blade and a brush roller. The toner used in the imaging apparatus has an average roundness ? within a range of 0.93˜0.99, and a friction coefficient ?s of the image carrier satisfies a condition, friction coefficient ?s?3.6?3.3×average roundness ?.
    Type: Grant
    Filed: March 17, 2006
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshio Koike, Eisaku Murakami, Masato Yanagida, Takeshi Shintani, Naohiro Kumagai, Atsushi Sampe, Masami Tomita, Hiroyuki Nagashima, Masanori Kawasumi, Takeshi Uchitani
  • Publication number: 20080056785
    Abstract: A disclosed gloss-providing sheet for providing high gloss to a toner image on a recording material by being placed on a toner image surface of the recording material, heated so as to fuse toner, and then separated from the recording material after the toner is cooled and solidified includes: a notification portion that changes a visual state thereof when a temperature of the gloss-providing sheet becomes equal to or lower than a glass transition temperature of the toner.
    Type: Application
    Filed: August 21, 2007
    Publication date: March 6, 2008
    Inventors: Hitoshi Maruyama, Kei Yasutomi, Eisaku Murakami, Reki Nakamura
  • Publication number: 20080008499
    Abstract: A charging member, which can be provided in a process cartridge and/or in an image forming apparatus, includes a conductive supporting member, an electrical resistance control layer formed on an outer circumferential surface of the conductive supporting member, and a nonconductive gap retaining member configured to retain a gap between the conductive supporting member and an image carrying member closely disposed to each other to have a constant distance. At least a portion of the nonconductive gap retaining member is mounted on the electrical resistance control layer at both ends of the conductive supporting member, and a circumference of the nonconductive gap retaining member projects from the electrical resistance control layer. An amount of projection of the gap retaining member from the electrical resistance control layer decreases as the gap retaining member tapers in a direction toward a center of an image formation region.
    Type: Application
    Filed: July 6, 2007
    Publication date: January 10, 2008
    Inventors: Masahiko Satoh, Masanori Kawasumi, Yoshiyuki Kimura, Eisaku Murakami, Hideki Zemba, Takeshi Uchitani, Shin Kayahara, Shunichi Hashimoto, Eiji Shimojo
  • Publication number: 20070286628
    Abstract: A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.
    Type: Application
    Filed: June 6, 2007
    Publication date: December 13, 2007
    Inventors: Shin KAYAHARA, Yoshiyuki Kimura, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Eiji Shimojo, Shunichi Hashimoto
  • Patent number: 7295796
    Abstract: A cleaningless image forming apparatus of the present invention uses spherical toner grains on surfaces of which a charge control agent and/or organic fine grains are present, thereby enhancing efficient image transfer. A brush roller collects, among toner grains left on a photoconductive drum after image transfer, toner grains of polarity opposite to preselected polarity and then releases them to the drum at preselected timing. The toner grains of opposite polarity are then transferred to an intermediate image transfer belt. When the toner grains of opposite polarity pass a charging zone assigned to a charge roller, a bias to the charge roller is interrupted or the charge roller is released from the drum.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: November 13, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisaku Murakami, Hideo Yoshizawa, Hiroyuki Nagashima, Yoshiyuki Kimura, Hideki Zemba, Eiji Kurimoto, Takeshi Uchitani, Toshio Koike, Masato Yanagida, Masami Tomita, Atsushi Sampe, Naohiro Kumagai, Takeshi Shintani, Masanori Kawasumi
  • Patent number: 7292817
    Abstract: An image forming apparatus includes a frame body, a frame cover supported by the frame body so as to be capable of opening and closing, an image forming unit that forms a toner image on an image carrier, a cleaning unit that removes and collects residual toner from the image carrier, and a toner container for accumulating the toner collected by the cleaning unit. The toner container is supported by the frame cover.
    Type: Grant
    Filed: December 13, 2006
    Date of Patent: November 6, 2007
    Assignee: Ricoh Company, Limited
    Inventors: Eisaku Murakami, Hideo Yoshizawa, Hiroyuki Nagashima, Yoshiyuki Kimura, Hideki Zemba, Eiji Kurimoto, Ishii Hiroshi, Yuji Arai
  • Patent number: 7272354
    Abstract: A cleaning unit includes a first blade and a second blade. The first blade is in contact with an image carrier or a paper carrier and removes adhered substances remained on surface of these. The second blade has an abrasive layer that is formed by including abrasive particles in an elastic material and is disposed in the downstream side of the first blade. The second blade is allowed to be in contact with the image carrier 1 or the paper carrier. Volume occupancy of abrasive particles in an area of contact of the second blade with either the image carrier or the paper carrier is not less than 50 percent and not more than 90 percent.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: September 18, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisaku Murakami, Masami Tomita, Masanori Kawasumi, Toshio Koike, Naohiro Kumagai, Atsushi Sampe, Takeshi Shintani, Masato Yanagida, Yutaka Takahashi, Hiroya Hirose, Shin Hasegawa, Hiroyuki Nagashima, Takeshi Uchitani, Kazunori Karasawa, Kentaroh Matsumoto, Tokuya Ohjimi, Mugijiroh Uno
  • Patent number: 7266324
    Abstract: A charging device including: a charging roller having a metal cylinder and an elastic layer located on the metal cylinder; a cleaner configured to clean the charging roller, which includes an electroconductive brush roller including a roller having a shaft; and hair located overlying the roller, wherein the hair includes a fiber which has a width of from 0.1 to 20 denier, and a length of from 0.3 to 2.5 mm and which is planted at a density of from 7,000 to 46,000 lines/cm2, and a member configured to impart substantially the same potential as that of the charging roller to the electroconductive brush roller when a bias voltage is applied to the charging roller. A process cartridge and an image forming apparatus including the charging device are also provided.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: September 4, 2007
    Assignee: Ricoh Company Limited
    Inventors: Masato Yanagida, Hiroyuki Nagashima, Naohiro Kumagai, Toshio Koike, Atsushi Sampe, Masanori Kawasumi, Eisaku Murakami, Takeshi Uchitani, Tokuya Ohjimi, Masami Tomita, Takeshi Shintani