Patents by Inventor Kenzo Tatsumi

Kenzo Tatsumi 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).

  • Publication number: 20060251984
    Abstract: The toner of the present invention is suitably used in SLIC development system where a liner velocity of a developer-bearing member is 150 to 500 cm/sec. The toner has resin particles containing at least a coloring agent, and a charge controlling agent fine articles, and a ratio M/T of the amount M (% by weight) of an element in the surface of toner particles as determined by X-ray photoelectron spectroscopy (XPS) to the amount T (% by weight) of the element in the entire toner particles of 20 to 500, which element is present only in a charge control agent among components of the toner and is an element belonging to one of the first, second, third, fourth, and fifth periods of the long form of periodic table of elements except hydrogen, carbon, oxygen, and rare gas elements.
    Type: Application
    Filed: July 10, 2006
    Publication date: November 9, 2006
    Inventors: Hiroshi Yamashita, Kenzo Tatsumi
  • Patent number: 7110710
    Abstract: The toner of the present invention is suitably used in SLIC development system where a liner velocity of a developer-bearing member is 150 to 500 cm/sec. The toner has resin particles containing at least a coloring agent, and a charge controlling agent fine articles, and a ratio M/T of the amount M (% by weight) of an element in the surface of toner particles as determined by X-ray photoelectron spectroscopy (XPS) to the amount T (% by weight) of the element in the entire toner particles of 20 to 500, which element is present only in a charge control agent among components of the toner and is an element belonging to one of the first, second, third, fourth, and fifth periods of the long form of periodic table of elements except hydrogen, carbon, oxygen, and rare gas elements.
    Type: Grant
    Filed: April 27, 2005
    Date of Patent: September 19, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yamashita, Kenzo Tatsumi
  • Publication number: 20060099012
    Abstract: A toner container for installation in a toner supply device is provided. The toner container includes a toner accommodation member and a cap member freely attachable to and detachable from the toner accommodation member. The toner accommodation member includes a bag member having an opening, and a connection member attached to the opening of the bag member and having a toner supply opening. The cap member is configured to receive toner supplied from the toner supply opening of the connection member of the toner accommodation member and to discharge the received toner. Either of the connection member of the toner accommodation member and the cap member includes a groove part and the other includes a protrusion part to engage with the groove part, and the cap member is attached to the toner accommodation member by engaging the groove part and the protrusion part with each other. The protrusion part elastically deforms to engage with the groove part.
    Type: Application
    Filed: October 24, 2005
    Publication date: May 11, 2006
    Inventors: Emi Kita, Takeroh Kurenuma, Kiyonori Tsuda, Masayuki Yamane, Nobuyuki Taguchi, Kazuhisa Sudo, Satoshi Narumi, Fumio Ogata, Seiji Terazawa, Kenzo Tatsumi, Keisuke Katoh
  • Patent number: 7027761
    Abstract: A developer carrier for an SLIC developing system includes a developing sleeve and a magnetic roll having a plurality of magnetic poles. A narrow development nip is formed by narrowing the width of a development pole forming a magnet brush and by narrowing a developer rising region in a developing region where a flux density attenuation ratio of the development pole is 40% or more. A half-value width of the flux density of the development pole is 22° or less and the flux density variation rate is 4.0 mT/Deg or more in a circumferential direction in a part where the flux density in at least half of that of a downstream side of a developer carrying direction from a peak magnetic force position of the development pole is 90% or less.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: April 11, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Kyohta Koetsuka, Tsuyoshi Imamura, Sumio Kamoi, Noriyuki Kamiya, Kenji Narita, Kenzo Tatsumi, Mieko Kakegawa
  • Publication number: 20050196692
    Abstract: The toner of the present invention is suitably used in SLIC development system where a liner velocity of a developer-bearing member is 150 to 500 cm/sec. The toner has resin particles containing at least a coloring agent, and a charge controlling agent fine articles, and a ratio M/T of the amount M (% by weight) of an element in the surface of toner particles as determined by X-ray photoelectron spectroscopy (XPS) to the amount T (% by weight) of the element in the entire toner particles of 20 to 500, which element is present only in a charge control agent among components of the toner and is an element belonging to one of the first, second, third, fourth, and fifth periods of the long form of periodic table of elements except hydrogen, carbon, oxygen, and rare gas elements.
    Type: Application
    Filed: April 27, 2005
    Publication date: September 8, 2005
    Inventors: Hiroshi Yamashita, Kenzo Tatsumi
  • Patent number: 6898383
    Abstract: A control system for an image forming device includes a sensor mounted on an optical path unobstructed by elements that are subject to wear for detecting a time varying signal representing reflected light from both a photoconductive element and a transfer sheet internal to the image forming device, a memory storing reference values, and a controller to control an image forming operation based on the reference values stored in the memory and the time-varying signal received from the sensor. The controller reads the time-varying signal from the sensor and compares the time-varying signal read to the reference values to determine a condition of the image forming device.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: May 24, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Publication number: 20040234299
    Abstract: A developer carrier used for an SLIC developing system. Characteristic values contributing to provide high image quality, which cannot be covered by the stipulations of the attenuation ratio and half-value width of the flux density are clarified. The developer carrier is constituted to be composed of the developing sleeve for carrying and transporting the developer, and a magnetic roll disposed in the developing sleeve, having a plurality of magnetic poles P1-P5. A narrow nip for development is realized by narrowing the width of the pole for development P1 forming the magnet brush by raising the developer in the developing region facing the latent image carrier, and by narrowing the rising region of the developer in the developing region and the flux density attenuation ratio of the pole for development P1 is 40% or more. The half-value width of the flux density of the pole for development P1 is 22% or less, and the flux density variation rate is 4.
    Type: Application
    Filed: March 5, 2004
    Publication date: November 25, 2004
    Inventors: Kyohta Koetsuka, Tsuyoshi Imamura, Sumio Kamoi, Noriyuki Kamiya, Kenji Narita, Kenzo Tatsumi, Mieko Kakegawa
  • Patent number: 6771918
    Abstract: A developing device, used in an image forming device where a developer supported on a developer supporter is thinned by a thinning member, and after being thinned, the developer is adhered to develop a latent image on an image supporter. An adjacent member (a developer scattering blocking member) is disposed at a position adjacent to the thinning member's downstream side in the developer supporter's moving direction, and the adjacent member's thinning member side of the opposite surface that is opposite to the developer supporter and the tip of the thinning member are disposed with an equal distance from the developer supporter. The opposite surface is gradually separated from the developer supporter at the downstream side of the developer supporter's moving direction.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: August 3, 2004
    Assignee: Ricoh Company, Ltd.
    Inventor: Kenzo Tatsumi
  • Publication number: 20040071475
    Abstract: A control system for an image forming device includes a sensor mounted on an optical path unobstructed by elements that are subject to wear for detecting a time varying signal representing reflected light from both a photoconductive element and a transfer sheet internal to the image forming device, a memory storing reference values, and a controller to control an image forming operation based on the reference values stored in the memory and the time-varying signal received from the sensor. The controller reads the time-varying signal from the sensor and compares the time-varying signal read to the reference values to determine a condition of the image forming device.
    Type: Application
    Filed: July 2, 2003
    Publication date: April 15, 2004
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Patent number: 6665511
    Abstract: In a developing device for an image forming apparatus of the present invention, a main magnetic pole for development has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream thereof in a direction of developer conveyance. A flux density between the main magnetic pole and the magnetic pole downstream of the main magnetic pole in the normal direction has a peak value that is 80% of the maximum flux density of the main pole in the normal direction or above. With this configuration, it is possible to reduce various defective images at the same time.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: December 16, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobutaka Takeuchi, Kenzo Tatsumi
  • Publication number: 20030219669
    Abstract: The toner of the present invention is suitably used in SLIC development system where a liner velocity of a developer-bearing member is 150 to 500 cm/sec. The toner has resin particles containing at least a coloring agent, and a charge controlling agent fine articles, and a ratio M/T of the amount M (% by weight) of an element in the surface of toner particles as determined by X-ray photoelectron spectroscopy (XPS) to the amount T (% by weight) of the element in the entire toner particles of 20 to 500, which element is present only in a charge control agent among components of the toner and is an element belonging to one of the first, second, third, fourth, and fifth periods of the long form of periodic table of elements except hydrogen, carbon, oxygen, and rare gas elements.
    Type: Application
    Filed: March 21, 2003
    Publication date: November 27, 2003
    Inventors: Hiroshi Yamashita, Kenzo Tatsumi
  • Patent number: 6628903
    Abstract: An image forming apparatus with a sensing control system having an optical sensor and a control device. A detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: September 30, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Publication number: 20030059228
    Abstract: A developing device, used in an image forming device where a developer supported on a developer supporter is thinned by a thinning member, and after being thinned, the developer is adhered to develop a latent image on an image supporter. An adjacent member (a developer scattering blocking member) is disposed at a position adjacent to the thinning member's downstream side in the developer supporter's moving direction, and the adjacent member's thinning member side of the opposite surface that is opposite to the developer supporter and the tip of the thinning member are disposed with an equal distance from the developer supporter.
    Type: Application
    Filed: September 20, 2002
    Publication date: March 27, 2003
    Inventor: Kenzo Tatsumi
  • Publication number: 20030021614
    Abstract: In a developing device for an image forming apparatus of the present invention, a main magnetic pole for development has an angle of 60° or below between opposite pole transition points respectively positioned upstream and downstream thereof in a direction of developer conveyance. A flux density between the main magnetic pole and the magnetic pole downstream of the main magnetic pole in the normal direction has a peak value that is 80% of the maximum flux density of the main pole in the normal direction or above. With this configuration, it is possible to reduce various defective images at the same time.
    Type: Application
    Filed: June 21, 2002
    Publication date: January 30, 2003
    Inventors: Nobutaka Takeuchi, Kenzo Tatsumi
  • Patent number: 6266501
    Abstract: An image-forming apparatus includes an image-bearing device that holds an electrostatic latent image and a toner image thereon, and a developer container that contains and agitates a developer having at least a toner. The image-forming apparatus also includes a developer-bearing device that carries the developer to develop the electrostatic latent image on the image-bearing device, and a density sensor that detects an optical density of a surface of the image-bearing device and a toner image on the image-bearing device. Further, the image-forming apparatus includes a developer seal that seals the developer in the developer container, wherein the seal is disposed between the developer container and the developer-bearing device, and an actuator configured to actuate the developer container and the developer-bearing device.
    Type: Grant
    Filed: January 14, 2000
    Date of Patent: July 24, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruji Mizuishi, Masaru Tanaka, Kenzo Tatsumi, Ken Amemiya, Toshitaka Yamaguchi, Hideki Zemba, Noriyuki Usui, Mayumi Ohori, Hiroshi Mizusawa
  • Patent number: 6148161
    Abstract: An image forming apparatus includes an image carrier and a developing device to develop a latent image formed on the image carrier by applying two-component developer, including toner, onto the latent image. The developing device includes a developing part containing the two-component developer and a developer stirring device to stir the two-component developer. A toner supplying device supplies toner to the developing part of the developing device, and a toner density detection device detects a toner density of the two-component developer in the developing device. A toner control device calculates a difference between an output value VT of the toner density detection device and a criterion value VTref for controlling the toner density of the two-component developer and controls the toner supplying device based upon the difference.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: November 14, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Noriyuki Usui, Ken Amemiya, Haruji Mizuishi, Mayumi Ohori, Masaru Tanaka, Kenzo Tatsumi, Toshitaka Yamaguchi, Hideki Zemba, Hiroshi Mizusawa
  • Patent number: 6144811
    Abstract: A image forming apparatus with a sensing control system having an optical sensor and a control device. An detected object is recognized by using the difference of an output characteristics correspond to a quantity of reflected light. Thus, one or more detected objects may be precisely detected by the one optical sensor.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: November 7, 2000
    Assignee: Ricoh Company
    Inventors: Mayumi Ohori, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Ohkaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Fumio Kishi
  • Patent number: 6144822
    Abstract: An image forming apparatus is provided, which includes an image bearing member, a transfer roller having a shaft for transferring an image on the image bearing member to a transfer sheet, a bearing mechanism for supporting the shaft, a discharging device for discharging the transfer, and a joint mechanism which mechanically connects the discharging device with the transfer roller at both ends of the shaft. Both of the transfer roller and the discharging device can be integrally detached from and attached to the image forming apparatus without detaching/attaching the bearing mechanism, by use of a handle. Therefore, an operation for replacing the transfer roller and the discharging device can be performed easily.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: November 7, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshitaka Yamaguchi, Masaru Tanaka, Hiroshi Mizusawa, Kenzo Tatsumi, Ken Amemiya, Haruji Mizuishi, Hideki Zemba, Noriyuki Usui, Mayumi Ohori
  • Patent number: 6128449
    Abstract: An image forming apparatus includes a charging element configured to apply a charging voltage to an image bearing member to charge the image bearing member, an optical writing device configured to form a latent image on a charged surface of the image bearing member charged by the charging element, a developer bearing member which carries developer including toner having a same polarity as that of the charging voltage to the image bearing member and which applies the toner to the latent image on the image bearing member to form a toner image when a developing bias voltage is applied thereto, and a control device which controls application of the charging voltage by the charging element and application of the developing bias voltage to the developer bearing member so as to increase an absolute value of the charging voltage to the image bearing member and an absolute value of the developing bias voltage to the developer bearing member to a predetermined value in a plurality of steps, respectively and wherein the
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: October 3, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideki Zenba, Masaru Tanaka, Haruji Mizuishi, Hiroyuki Okaji, Kenzo Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Mayumi Ohori
  • Patent number: 5915143
    Abstract: An image forming apparatus which is capable of adjusting toner density in response to variations of humidity. The image forming apparatus includes a toner density detector that detects the density of toner inside an image developer, a humidity detector that detects toner humidity inside the image forming apparatus, and a controller that controls a toner supplier on the basis of the toner density detected by the toner density detector and that adjusts the toner density in accordance with variations of humidity detected by the humidity detector. The humidity detector is located at a position where the humidity detector can detect humidity of air around the image developer and where the humidity detector is minimally affected by heated air.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: June 22, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Watanabe, Masaru Tanaka, Haruji Mizuishi, Hiroshi Yoshinaga, Kenzo Tatsumi, Toshitaka Yamaguchi, Takeo Suda, Ken Amemiya, Mayumi Ohori