Patents by Inventor Naohiro Kumagai

Naohiro Kumagai 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: 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
  • 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: 20080081847
    Abstract: To provide a flexible polyurethane foam having good vibration characteristics and suitable particularly for a seat for an automobile. A flexible polyurethane foam obtained by reacting a high molecular weight polyoxyalkylene polyol or a polymer-dispersed polyol containing fine polymer particles in the high molecular weight polyoxyalkylene polyol, with a polyisocyanate compound, in the presence of a catalyst, a blowing agent and a foam stabilizer, characterized in that an amino-modified silicone (F) having a silicon atom and a nitrogen atom in its molecule is used in an amount of from 0.00001 to 1 part by mass per 100 parts by mass of all active hydrogen compounds.
    Type: Application
    Filed: November 26, 2007
    Publication date: April 3, 2008
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Takayuki SASAKI, Takashi Ito, Yoshinori Toyota, Naohiro Kumagai
  • Publication number: 20080013998
    Abstract: A powder transport unit for transporting powders includes a transport pipe, a powder transport member, and a regulating member. The transport pipe is curvingly extended. The powder transport member is disposed in an entire length of the transport pipe and rotates in the transport pipe to transport the powders. The regulating member is integrally formed with the transport pipe at a downstream end of the transport pipe, and regulates a length of the powder transport member disposed in the entire length of the transport pipe. The regulating member includes an exit hole to pass through the powders transported by the powder transport member in the transport pipe.
    Type: Application
    Filed: September 28, 2006
    Publication date: January 17, 2008
    Inventors: Naohiro Kumagai, Masato Yanagida, Shuji Tanaka, Takatsugu Fujishiro, Hiroomi Harada, Takeshi Tabuchi, Tokuya Ojimi, Chohtaroh Kataoka, Takaaki Tawada, Shinichi Kawahara, Haruji Mizuishi
  • 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: 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
  • Publication number: 20070172273
    Abstract: A lubricant applying unit, included in a process cartridge provided in an image forming apparatus, includes a solid lubricant, a lubricant supporting unit to support the solid lubricant, a lubricant holder to accommodate the solid lubricant supported by the lubricant supporting unit, a pressing mechanism located between the lubricant supporting unit and the lubricant holder and designed to press the solid lubricant against a lubricant applying member, and a frictional resistance reducing member to reduce a frictional resistance produced at sliding contact portions between the lubricant supporting unit and internal surfaces of the lubricant holder.
    Type: Application
    Filed: January 22, 2007
    Publication date: July 26, 2007
    Inventors: Hiroomi Harada, Shuji Tanaka, Naohiro Kumagai
  • Publication number: 20070154246
    Abstract: A cleaning device, a process cartridge, an image forming apparatus and toner are disclosed to maintain improved cleaning performance for a long time. The cleaning device includes a cleaning blade, an antifriction agent coating part and a toner removing part. The cleaning blade is disposed in contact with a surface of an image support body. The antifriction agent coating part coats a solid antifriction agent on the surface of the image support body, and is disposed in an upstream side from the 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.
    Type: Application
    Filed: March 13, 2007
    Publication date: July 5, 2007
    Inventors: Takeshi Shintani, Takuji Yoneda, Toshio Koike, Masato Yanagida, Naohiro Kumagai, Hiroyuki Nagashima, Atsushi Sampe, Eisaku Murakami, Masanori Kawasumi, Takeshi Uchitani, Masami Tomita
  • Patent number: 7228099
    Abstract: A cleaning device, a process cartridge, an image forming apparatus and toner are disclosed to maintain improved cleaning performance for a long time. The cleaning device includes a cleaning blade, an antifriction agent coating part and a toner removing part. The cleaning blade is disposed in contact with a surface of an image support body. The antifriction agent coating part coats a solid antifriction agent on the surface of the image support body, and is disposed in an upstream side from the 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.
    Type: Grant
    Filed: May 3, 2004
    Date of Patent: June 5, 2007
    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
  • Patent number: 7218877
    Abstract: A charging device including a charging roller having a metal cylinder and an elastic layer located thereon, and a cleaner for cleaning the surface of the charging roller. The cleaner includes a driving shaft and a cleaning roller which is rotatably mounted on the driving shaft. The cleaning roller is made of a non-cellular foam resin having a density of from 5 to 15 kg/m3 and a tensile strength of from 1.2 to 2.2 kg/cm2.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: May 15, 2007
    Assignee: Ricoh Company Limited
    Inventors: Masato Yanagida, Hiroyuki Nagashima, Naohiro Kumagai, Toshio Koike, Atsushi Sampe, Masanori Kawasumi, Eisaku Murakami, Takeshi Uchitani, Masami Tomita, Takeshi Shintani, Tsutomu Yamakami
  • Publication number: 20070059067
    Abstract: A process cartridge including an image bearing member; a lubricant applicator, which includes a lubricant application member configured to apply a solid lubricant to the surface of the image bearing member; and a smoothing member configured to smooth the applied solid lubricant, and at least one of a charging device, a developing device and a cleaning device, wherein the amount of the solid lubricant present on a portion of surface of the image bearing member, which is located between the lubricant application member and the smoothing blade, is from 0.11 to 1.2 mg/m2. The smoothing member is preferably a blade having a JIS-A hardness of not less than 79°. The process cartridge is preferably assembled by a method including setting the lubricant smoothing member, the lubricant and the lubricant application member to a housing of the process cartridge; and then setting the image bearing member to the housing.
    Type: Application
    Filed: September 13, 2006
    Publication date: March 15, 2007
    Inventors: Shuji Tanaka, Shinichi Kawahara, Yoshiyuki Kimura, Hiroshi Hosokawa, Yoshio Hattori, Takeo Suda, Yutaka Takahashi, Takatsugu Fujishiro, Teruyuki Kasuga, Hiroomi Harada, Tokuya Ojimi, Masato Yanagida, Takaaki Tawada, Takeshi Tabuchi, Naohiro Kumagai, Chohtaroh Kataoka, Hidemasa Sato
  • Publication number: 20070036595
    Abstract: A cleaning unit includes a cleaning blade that cleans toner on an image carrier and a brush-shaped roller that applies a lubricant of a molded lubricant on the image carrier. The brush-shaped roller is insulative, and delivers the toner cleaned by the cleaning blade to inside of the cleaning unit.
    Type: Application
    Filed: October 25, 2006
    Publication date: February 15, 2007
    Inventors: Ken Amemiya, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Takaaki Tawada, Yuji Arai, Toshio Koike, Takuji Yoneda, Takeshi Tabuchi, Yutaka Takahashi, Eisaku Murakami, Takeshi Uchitani, Masami Tomita, Masanori Kawasumi
  • Publication number: 20070014588
    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: Application
    Filed: June 30, 2006
    Publication date: January 18, 2007
    Inventors: Masato Yanagida, Hiroyuki Nagashima, Naohiro Kumagai, Toshio Koike, Atsushi Sampe, Masanori Kawasumi, Eisaku Murakami, Takeshi Uchitani, Tokuya Ohjimi, Masami Tomita, Takeshi Shintani
  • Patent number: 7149465
    Abstract: A cleaning unit includes a cleaning blade that cleans toner on an image carrier and a brush-shaped roller that applies a lubricant of a molded lubricant on the image carrier. The brush-shaped roller is insulative, and delivers the toner cleaned by the cleaning blade to inside of the cleaning unit.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: December 12, 2006
    Assignee: Ricoh Company, Limited
    Inventors: Ken Amemiya, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Takaaki Tawada, Yuji Arai, Toshio Koike, Takuji Yoneda, Takeshi Tabuchi, Yutaka Takahashi, Eisaku Murakami, Takeshi Uchitani, Masami Tomita, Masanori Kawasumi
  • Patent number: 7139504
    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: February 11, 2004
    Date of Patent: November 21, 2006
    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
  • Patent number: 7130564
    Abstract: An image forming apparatus includes an image bearing member configured to form an electrostatic latent image on a surface thereof, and a separating mechanism configured to separate an irregular charge toner from a residual toner remaining on the surface of the image bearing member after a completion of an image forming process, to provide an extra travel passage to give a time delay to the irregular charge toner, and to return the irregular charge toner with the time delay to the surface of the image bearing member.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: October 31, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisaku Murakami, Toshio Koike, Masato Yanagida, Naohiro Kumagai, Takeshi Shintani, Masanori Kawasumi, Atsushi Sampe, Masami Tomita, Hiroyuki Nagashima, Takeshi Uchitani
  • Publication number: 20060216085
    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: Application
    Filed: May 26, 2006
    Publication date: September 28, 2006
    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: 7110696
    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: September 24, 2003
    Date of Patent: September 19, 2006
    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