Patents by Inventor Yasunori Kawaishi

Yasunori Kawaishi 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: 6212351
    Abstract: An image forming apparatus and method of using the apparatus including: an image carrier; and an intermediate image transfer unit.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: April 3, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsuya Kawagoe, Shin Kayahara, Yasunori Kawaishi
  • Patent number: 6125257
    Abstract: The current methods and systems for cleaning residual ultra-fine spherical toner from an image forming surface discloses the application of aspherical toner to a cleaning blade. The aspherical toner is generally larger than the ultra-fine spherical toner which provides a superior image on an image-carrying medium. According to one preferred embodiment of the current invention, the aspherical black toner is placed in a predetermined area outside of a desired image area where the ultra-fine spherical toner in multiple colors is placed. The aspherical toner is transported to the cleaning blade before the multi-color toner reaches the cleaning blade. Since the aspherical toner applied at a contacting edge of the cleaning blade provide an effective seal or trap between the cleaning blade and the image forming surface, the ultra-fine spherical toner is effectively removed from the image forming surface.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: September 26, 2000
    Assignee: Ricoh Co., Ltd.
    Inventors: Takeyoshi Sekine, Hiroshi Yamasita, Hiroyuki Fushimi, Makoto Ohsaki, Kouta Fujimdri, Yasunori Kawaishi, Jun Okamoto
  • Patent number: 6057869
    Abstract: An image forming apparatus of the type forming a toner image on a photoconductive drum or similar image carrier, transferring it to a paper or similar transfer medium via an intermediate transfer body, e.g., belt, and fixing it on the medium by a fixing device is disclosed. Just after the transfer of a toner image of the last color which is to lie over the other toner images on the intermediate transfer belt, the peripheral speed of the belt is switched to a comparatively low speed matching a fixing and paper transport speed. At this instant, the belt is moved away from the drum. The length of the transfer medium and the distance between a paper transfer position and a fixing position is compared. For a relatively short transfer medium, the peripheral speed of the belt is not switched to the low speed.
    Type: Grant
    Filed: August 19, 1997
    Date of Patent: May 2, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasunori Kawaishi, Kenichi Mizuma, Hideya Furuta, Yoshihiro Sakai, Leo Munakata, Hideki Kamiyama, Minoru Sugiyama
  • Patent number: 5701566
    Abstract: A device incorporated in an image forming apparatus for transferring a toner image from a photoconductive element to an intermediate transfer belt and then from the intermediate transfer belt to a sheet or similar recording medium. An electrode member is implemented as a belt drive roller and located at the rear of a portion of the intermediate transfer belt which lies in a position for transferring the toner image from the belt to a sheet. The electrode member has a specific volume resistance of 10.sup.7 .OMEGA.cm to 10.sup.12 .OMEGA.cm.
    Type: Grant
    Filed: September 5, 1995
    Date of Patent: December 23, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Bisaiji, Hideo Yu, Yasunori Kawaishi, Toshiaki Motohashi, Mitsuru Takahashi, Hideki Kamiyama
  • Patent number: 5666622
    Abstract: The apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode so as form a potential gradient. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: September 9, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuko Harasawa, Itaru Matsuda, Satoshi Takano, Hideo Yu, Yasunori Kawaishi, Hideki Kamiyama, Toshiaki Motohashi, Mitsuru Takahashi, Takashi Bisaiji
  • Patent number: 5648842
    Abstract: The current methods and systems for cleaning residual ultra-fine spherical toner from an image forming surface discloses the application of aspherical toner to a cleaning blade. The aspherical toner is generally larger than the ultra-fine spherical toner which provides a superior image on an image-carrying medium. According to one preferred embodiment of the current invention, the aspherical black toner is placed in a predetermined area outside of a desired image area where the ultra-fine spherical toner in multiple colors is placed. The aspherical toner is transported to the cleaning blade before the multi-color toner reaches the cleaning blade. Since the aspherical toner applied at a contacting edge of the cleaning blade provide an effective seal or trap between the cleaning blade and the image forming surface, the ultra-fine spherical toner is effectively removed from the image forming surface.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: July 15, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Takeyoshi Sekine, Hiroshi Yamasita, Hiroyuki Fushimi, Makoto Ohsaki, Kouta Fujimdri, Yasunori Kawaishi, Jun Okamoto
  • Patent number: 5461461
    Abstract: An image forming apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can also be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: October 24, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuko Harasawa, Itaru Matsuda, Satoshi Takano, Hideo Yu, Yasunori Kawaishi, Hideki Kamiyama, Toshiaki Motohashi, Mitsuru Takahashi, Takashi Bisaiji
  • Patent number: 5442428
    Abstract: An image recording apparatus is disclosed which includes an intermediate transfer belt rotatable in a reciprocating motion. Before the belt is rotated back and forth for forming a composite toner image, it is rotated in the opposite direction to the image forming direction. This provides the belt with substantially the same deviation in both the forward movement and the reverse movement. Hence, the apparatus insures desirable images by preventing the individual toner images from being brought out of register due to the deviation of the belt.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: August 15, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuru Takahashi, Yasunori Kawaishi, Hideo Yu, Toshiaki Motohashi, Katsuya Kawagoe, Hideki Kamiyama
  • Patent number: 5291252
    Abstract: A multicolor image forming apparatus having an image transfer structure capable of preventing a transferred image and an image formed on a photoconductive element from being dislocated from each other. A backup roller facing a photoconductive element and a tension roller are movable toward and away from the element at the same time over the same distance. A single cam intervenes between support members supporting the two rollers and moves the rollers by half a rotation thereof.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: March 1, 1994
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasunori Kawaishi
  • Patent number: 5278613
    Abstract: An image forming apparatus which insures stable image transfer at all times with no regard to aging and environment. An electrometer is located in close proximity to and opposite to a transfer region where an image carrier and a transfer medium face each other. A voltage to be applied to an electrode which applies a transfe voltage to the transfer medium is controlled in response to the output of the electrometer such that the electric field in the transfer region remains constant.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: January 11, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Bisaiji, Yasunori Kawaishi, Makoto Ohsaki
  • Patent number: 5162859
    Abstract: A copier, laser printer or similar image forming apparatus of the type having an intermediate image transfer body in the form of a belt allows documents to be reproduced in a page-sequential paper discharge mode which discharges paper sheets, or recording media, in order of page. When an automatic two-sided copy mode is selected, the apparatus automatically sets up the page-sequential paper discharge mode. Hence, when two sided black-and-white documents and color documents are reproduced together in the automatic two-sided copy mode, paper sheets are driven out of the apparatus in order of page.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: November 10, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Tatsuo Hirono, Yasunori Kawaishi, Nobuo Kasahara
  • Patent number: 5160969
    Abstract: An image forming apparatus has a plurality of developing containers for developing an electrostatic latent image of a latent image carrier by toners having colors different from each other except for black; a black developing container for color for storing black toner for color and operated when the developed image on the latent image carrier every color is overlapped and transferred onto a transfer material to provide a color image; a black developing container for a monochromatic image for storing black toner for a monochromatic image and operated when the monochromatic image is obtained; and a device for arranging the respective developing containers such that the developing containers are opposite to the latent image carrier. The other image forming apparatuses are also shown.
    Type: Grant
    Filed: May 29, 1991
    Date of Patent: November 3, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Kenichi Mizuma, Hideya Furuta, Nobuo Kasahara, Noriyuki Kimura, Shinju Nagatsuna, Mitsuru Mamizuka, Yoshihiro Sakai, Kazunori Bannai, Kazushige Taguchi, Yasunori Kawaishi, Makoto Ohsaki, Tatsuo Hirono
  • Patent number: 5159392
    Abstract: An image forming apparatus for forming an image on one or both sides of a recording medium includes a rotatable photoconductive element on which latent images are optically written, a developer which develops the images to produce a primary toner image on the photoconductive element, a belt which faces the photoconductive element, and onto which the toner image is transferred when a paper sheet is not present. A charged roller is close to and above an upper portion of the belt and downstream from the photoconductive element. The charged roller holds the paper on the belt and also transfers toner onto the underside of the paper.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: October 27, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobuo Kasahara, Yasunori Kawaishi, Tatsuo Hirono
  • Patent number: 5142339
    Abstract: An image recorder capable of preventing a non-fixed toner image carried on a paper sheet from being rubbed with no regard to the elasticity or the thickness of the paper sheet. A belt transports the paper sheet with a non-fixed toner image. An upper guide plate and a lower guide plate face each other for guiding the paper sheet to a fixing device. The relative position of the upper and lower guide plates and the belt is variable to prevent the non-fixed toner image from contacting the upper or lower guide plate.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: August 25, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobuo Kasahara, Yasunori Kawaishi, Tatsuo Hirono
  • Patent number: 4571056
    Abstract: A fixing device including a heating roller and a pressure applying roller maintained in pressing contact with each other and allowing a toner image bearing recording sheet to pass therebetween has a heat insulating structure enclosing at least a portion of the fixing device and a multiple wall structure for defining an air passage.
    Type: Grant
    Filed: March 19, 1984
    Date of Patent: February 18, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Tatsuo Tani, Yasunori Kawaishi
  • Patent number: 4348106
    Abstract: A guide apparatus for guiding a movable contact glass, which serves as an original table in an electrophotographic copying machine, to a predetermined exposure position for slit exposure, without any inclination of the contact glass, comprising a drive member for reciprocating the contact glass in the exposure scanning direction and a guide member, which is shorter than the distance from the exposure position to the center of gravity of the contact glass at completion of the exposure scanning and whose upper surface at the exposure position is higher than the other upper surface thereof.The drive apparatus comprises a loop drive transmission member which is rotated in one direction and which substantially reciprocates the contact glass and can have a lock release apparatus capable of making the contact glass movable manually when the contact glass is stopped at its dead point.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: September 7, 1982
    Assignee: Ricoh Co., Ltd.
    Inventors: Shigeru Suzuki, Yukihiro Ohno, Nobuyuki Yanagawa, Yasunori Kawaishi
  • Patent number: RE38206
    Abstract: A device incorporated in an image forming apparatus for transferring a toner image from a photoconductive element to an intermediate transfer belt and then from the intermediate transfer belt to a sheet or similar recording medium. An electrode member is implemented as a belt drive roller and located at the rear of a portion of the intermediate transfer belt which lies in a position for transferring the toner image from the belt to a sheet. The electrode member has a specific volume resistance of 107 &OHgr;cm to 1012 &OHgr;cm.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: July 29, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Bisaiji, Hideo Yu, Yasunori Kawaishi, Toshiaki Motohashi, Mitsuru Takahashi, Hideki Kamiyama