Patents by Inventor Takafumi Wakai

Takafumi Wakai 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: 9002244
    Abstract: A developing device including a toner holding member that faces but is not in contact with an image carrier carrying a latent image and that rotates while holding a nonmagnetic toner, a charging member that charges the toner, and a developing electric field forming unit that forms a developing electric field at least including a direct current component to cause the charged toner to fly and adhere to the latent image to develop the latent image. When the developing electric field is applied such that the toner is caused to fly toward the image carrier by the direct current component of the developing electric field, maintaining a non-electrostatic adhesion of the toner to the toner holding member to be about 2 nN or more under a low-temperature low-humidity environment of a temperature of 10° C. and a relative humidity of 15%. The toner holding member's surface has a specific surface roughness specified by a specific oil retention volume.
    Type: Grant
    Filed: January 18, 2013
    Date of Patent: April 7, 2015
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yoshifumi Ozaki, Shinji Mitsui, Akihiko Noda, Masahiro Andoh, Hisashi Murase, Takafumi Wakai, Munenobu Okubo, Masaru Sakuma, Yasuyuki Tsutsumi, Hirokazu Hamano, Kazuaki Iikura, Yosuke Ninomiya
  • Publication number: 20140147142
    Abstract: There is provided a developing device including a toner holding member that is rotatably provided to face an image holding member and holds and transports a nonmagnetic single-component toner toward a development region to develop an electrostatic latent image on the image holding member, a supplying member that is rotatably provided in elastic contact with the toner holding member to supply the toner from a contact region therebetween to the toner holding member, a toner replenishing unit that faces a replenishment region at a portion apart from the contact region to replenish a new toner, and a regulating member that is provided on a downstream side of the contact region in a rotation direction thereof and on an upstream side of the development region to triboelectrically charge the toner held on the toner holding member and regulate the amount of toner provided for the development.
    Type: Application
    Filed: May 1, 2013
    Publication date: May 29, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masaru SAKUMA, Munenobu OKUBO, Shinji MITSUI, Yasuyuki TSUTSUMI, Kazuaki IIKURA, Yosuke NINOMIYA, Yoshifumi OZAKI, Akihiko NODA, Hirokazu HAMANO, Takafumi WAKAI
  • Publication number: 20140147141
    Abstract: A developing device includes a transporting unit that rotates while facing an image carrier that carries an electrostatic latent image, the transporting unit transporting developer toward the image carrier; a feeding unit that contacts the transporting unit to feed the developer to the transporting unit; a transport path that connects a containing chamber that contains the developer to a feeding chamber that houses the feeding unit; a supplying unit that retains the developer to be supplied in the transport path and supplies the developer to the feeding unit in a supply region that is separated from a contact region in which the feeding unit contacts the transporting unit; and an attaching unit that is disposed downstream of the contact region and upstream of the supply region in a rotation direction of the feeding unit and that attaches the developer to the feeding unit at a location below the contact region.
    Type: Application
    Filed: April 18, 2013
    Publication date: May 29, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Munenobu OKUBO, Yasuyuki TSUTSUMI, Shinji MITSUI, Kazuaki IIKURA, Yosuke NINOMIYA, Yoshifumi OZAKI, Akihiko NODA, Hirokazu HAMANO, Takafumi WAKAI, Masaru SAKUMA
  • Publication number: 20140147144
    Abstract: A developing device includes a toner holding member that is rotatably installed opposite to an image holding member which holds a latent image and circularly moves, a supply member that has a rough surface capable of capturing toner, a toner supply portion that supplies new toner, and a restriction member that restricts an amount of toner used for development, wherein the toner supply portion connects an accommodation chamber to a developing chamber via a toner transport path, wherein a developing chamber side opening is located on a lower side of an accommodation chamber side opening of the toner transport path, and wherein a width size in a direction following a rotation direction of the supply member in the developing chamber side opening of the toner transport path is set to be smaller than an outer diameter of the supply member in a projection plane viewed from the supply member side.
    Type: Application
    Filed: May 7, 2013
    Publication date: May 29, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Shinji MITSUI, Munenobu OKUBO, Yasuyuki TSUTSUMI, Kazuaki IIKURA, Yosuke NINOMIYA, Yoshifumi OZAKI, Akihiko NODA, Hirokazu HAMANO, Takafumi WAKAI, Masaru SAKUMA
  • Patent number: 8688018
    Abstract: A developing device includes a container, a toner holding member, a developing electric field forming unit, a layer forming unit, an electrode member, and a low-frequency electric field forming unit. The container accommodates toner. The toner holding member holds toner and transports the toner to a developing region where the toner holding member and the latent image holding member face. The developing electric field forming unit forms a developing electric field for developing a latent image held on a latent image holding member. The layer forming unit forms a toner layer on the toner holding member prior to the developing region. The electrode member faces the toner holding member. The low-frequency electric field forming unit forms a low-frequency electric field acting on residual toner between the electrode member and the toner holding member, and forms stripe-shaped projections in accordance with a period of the low-frequency electric field.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: April 1, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tsutomu Uezono, Takafumi Wakai, Yasuyuki Tsutsumi
  • Publication number: 20140056623
    Abstract: A development method is used for a developing device including a toner holding member that faces but is not in contact with an image carrier carrying a latent image and that rotates while holding a nonmagnetic toner, a charging member that charges the toner, and a developing electric field forming unit that forms a developing electric field at least including a direct current component to cause the charged toner to fly and adhere to the latent image to develop the latent image. The method includes, when the developing electric field is applied such that the toner is caused to fly toward the image carrier by the direct current component of the developing electric field alone, maintaining a non-electrostatic adhesion of the toner to the toner holding member to be about 2 nN or more under a low-temperature low-humidity environment of a temperature of 10° C. and a relative humidity of 15%.
    Type: Application
    Filed: January 18, 2013
    Publication date: February 27, 2014
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yoshifumi OZAKI, Shinji MITSUI, Akihiko NODA, Masahiro ANDOH, Hisashi MURASE, Takafumi WAKAI, Munenobu OKUBO, Masaru SAKUMA, Yasuyuki TSUTSUMI, Hirokazu HAMANO, Kazuaki IIKURA, Yosuke NINOMIYA
  • Publication number: 20130051869
    Abstract: A developing device includes a container, a toner holding member, a developing electric field forming unit, a layer forming unit, an electrode member, and a low-frequency electric field forming unit. The container accommodates toner. The toner holding member holds toner and transports the toner to a developing region where the toner holding member and the latent image holding member face. The developing electric field forming unit forms a developing electric field for developing a latent image held on a latent image holding member. The layer forming unit forms a toner layer on the toner holding member prior to the developing region. The electrode member faces the toner holding member. The low-frequency electric field forming unit forms a low-frequency electric field acting on residual toner between the electrode member and the toner holding member, and forms stripe-shaped projections in accordance with a period of the low-frequency electric field.
    Type: Application
    Filed: February 22, 2012
    Publication date: February 28, 2013
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Tsutomu UEZONO, Takafumi WAKAI, Yasuyuki TSUTSUMI
  • Patent number: 8238802
    Abstract: A developing unit includes a developer receiving vessel and a developer conveyance member as defined herein, the developer conveyance member includes a rotary shaft, a first conveyance member and a second conveyance member as defined herein, the second conveyance member is supported on the rotary shaft and bent in contact with the wall surface of the developer receiving chamber with rotation of the rotary shaft while conveying the developer toward the developer retainer, and the second conveyance member includes a second conveyance member body supported on the rotary shaft and located out of the overlapping range, and a second overlapping portion extending from the second conveyance member body to the other axial end of the overlapping range, designed to be movable relatively to the rotary shaft and disposed adjacently to an upstream side of the first overlapping portion in a rotation direction.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: August 7, 2012
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tomoyuki Kawakami, Takafumi Wakai, Koichi Tanaka
  • Publication number: 20100124444
    Abstract: A developing unit includes a developer receiving vessel and a developer conveyance member as defined herein, the developer conveyance member includes a rotary shaft, a first conveyance member and a second conveyance member as defined herein, the second conveyance member is supported on the rotary shaft and bent in contact with the wall surface of the developer receiving chamber with rotation of the rotary shaft while conveying the developer toward the developer retainer, and the second conveyance member includes a second conveyance member body supported on the rotary shaft and located out of the overlapping range, and a second overlapping portion extending from the second conveyance member body to the other axial end of the overlapping range, designed to be movable relatively to the rotary shaft and disposed adjacently to an upstream side of the first overlapping portion in a rotation direction.
    Type: Application
    Filed: September 1, 2009
    Publication date: May 20, 2010
    Inventors: Tomoyuki Kawakami, Takafumi Wakai, Koichi Tanaka
  • Patent number: 7620352
    Abstract: A developing device comprises: a case having a developing opening; a cylindrical-shaped developer carry member disposed exposed in part to the developing opening, and rotatable for holding and carrying a developer; and a magnet member disposed fixed within the developer carry member and comprising two or more magnetic poles including a developing magnetic pole and a developer peel-off magnetic pole. In such portion of the case that not only is opposed to the outer peripheral surface of the developer carry member after it passes through the developing area but also corresponds to an area which extends from the developing magnetic pole in the rotation direction up to the developer peel-off magnetic pole and provides a normal direction magnetic flux density of 20 mT or less, a projecting portion where a clearance between its opposed portion and the outer peripheral surface of the developer carry member becomes narrowest is formed.
    Type: Grant
    Filed: April 6, 2007
    Date of Patent: November 17, 2009
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Ichiro Kawahara, Takafumi Wakai
  • Publication number: 20080080906
    Abstract: A developing device comprises: a case having a developing opening; a cylindrical-shaped developer carry member disposed exposed in part to the developing opening, and rotatable for holding and carrying a developer; and a magnet member disposed fixed within the developer carry member and comprising two or more magnetic poles including a developing magnetic pole and a developer peel-off magnetic pole. In such portion of the case that not only is opposed to the outer peripheral surface of the developer carry member after it passes through the developing area but also corresponds to an area which extends from the developing magnetic pole in the rotation direction up to the developer peel-off magnetic pole and provides a normal direction magnetic flux density of 20 mT or less, a projecting portion where a clearance between its opposed portion and the outer peripheral surface of the developer carry member becomes narrowest is formed.
    Type: Application
    Filed: April 6, 2007
    Publication date: April 3, 2008
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Ichiro Kawahara, Takafumi Wakai