Patents by Inventor Hideki Zenba

Hideki Zenba 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: 8320799
    Abstract: An image forming apparatus includes a first image formation unit that forms a black toner image, and a detachable second image formation unit that forms a color toner image. A first toner supply unit is provided to supply the black toner to the first image formation unit. A second toner supply unit is provided to supply one of a black and component color toner to the first and second image formation units in accordance with a color mode. A first conveyance path is provided to convey the black toner to the first image formation unit. A second conveyance path is also provided to convey the component color toner stored in the second toner container section to the second image formation unit. The second toner supply unit is selectively connected to one of the first and second conveyance paths in accordance with the color mode.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: November 27, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryuji Yoshida, Mikio Ishibashi, Nobuyuki Koinuma, Hideki Zenba, Naoyuki Ozaki, Hiroaki Maeda, Mugijirou Uno, Shunichi Hashimoto, Yoshinori Nakagawa, Tomoko Takahashi
  • Publication number: 20110064475
    Abstract: An image forming apparatus includes a first image formation unit that forms a black toner image, and a detachable second image formation unit that forms a color toner image. A first toner supply unit is provided to supply the black toner to the first image formation unit. A second toner supply unit is provided to supply one of a black and component color toner to the first and second image formation units in accordance with a color mode. A first conveyance path is provided to convey the black toner to the first image formation unit. A second conveyance path is also provided to convey the component color toner stored in the second toner container section to the second image formation unit. The second toner supply unit is selectively connected to one of the first and second conveyance paths in accordance with the color mode.
    Type: Application
    Filed: September 14, 2010
    Publication date: March 17, 2011
    Inventors: Ryuji YOSHIDA, Mikio Ishibashi, Nobuyuki Koinuma, Hideki Zenba, Naoyuki Ozaki, Hiroaki Maeda, Mugijirou Uno, Shunichi Hashimoto, Yoshinori Nakagawa, Tomoko Takahashi
  • 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: 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: 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
  • Patent number: 6160969
    Abstract: An image forming apparatus transfers a toner image from a photoconductive image carrier to a recording medium with a transfer roller and senses the density of a particular toner pattern formed on the image carrier with an optical sensor. A voltage of a first polarity opposite the polarity of the toner is applied to the transfer roller when the toner image is to be transferred to the recording medium. A voltage of a second polarity identical to the polarity of the toner is applied to the transfer roller when the toner pattern is to be moved between the image carrier and the transfer roller. Thus, even when a toner pattern is brought to the transfer roller, the transfer roller is not released from the photoconductive element.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: December 12, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Kouji Ishigaki, Haruji Mizuishi, Masaru Tanaka, Hiroyuki Ohkaji, Kenzou Tatsumi, Hiroshi Mizusawa, Ken Amemiya, Hideki Zenba, Mayumi Ohori
  • 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: 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: 6085062
    Abstract: An electrophotographic image forming apparatus is disclosed which is provided within a cleaning device with a rotative conveying member for conveying a residual toner after removal thereof from a photoreceptor up to an inlet of a toner dropping path while rotating. Within the toner dropping path is disposed a toner bridge preventing member for preventing the formation of a toner bridge in the same path. The toner bridge preventing member is driven by the rotative conveying member so as to reciprocate substantially in parallel with the toner dropping direction.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: July 4, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruji Mizuishi, Ken Amemiya, Hiroshi Mizusawa, Hiroyuki Ohkaji, Mayumi Ohori, Masaru Tanaka, Hideki Zenba, Kenzou Tatsumi