Patents by Inventor Masaaki Tokunaga

Masaaki Tokunaga 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: 20110110686
    Abstract: An image forming apparatus includes: an image carrier; an intermediate transfer unit including an intermediate transfer body onto which an image on the image carrier is transferred, and plural rotation members around which the intermediate transfer body is wound, each rotation member rotating around a rotation axis, the intermediate transfer unit detachably attached, in the rotation axis direction, to an apparatus main body; a secondary transfer unit that makes contact with and separates from the intermediate transfer body, the secondary transfer unit provided at an opposite side of the rotation members across the intermediate transfer body; a positioning unit that, when the intermediate transfer unit is attached to the apparatus main body, positions the intermediate transfer unit in the secondary transfer unit side at least at two points differently located in the rotation axis direction; and a securing unit that secures the intermediate transfer unit to the apparatus main body.
    Type: Application
    Filed: May 26, 2010
    Publication date: May 12, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Naoto YOSHINO, Masaaki TOKUNAGA
  • Publication number: 20110110684
    Abstract: An image forming apparatus including: an image carrier, provided to a main body of the image forming apparatus, that carries a toner image; an opening and closing member provided to be openable and closable against the main body; a transfer unit movably provided against the opening and closing member, the transfer unit including: a transfer body transferring the toner image onto a transfer receiving medium; and a holding member holding the transfer body and having a contact portion that is in contact with a counterpart contact portion provided to the main body when the opening and closing member is closed; and a maintaining unit maintaining a posture of the transfer unit against the opening and closing member when the contact portion is brought into contact with the counterpart contact portion during the course of transition of the opening and closing member from an opened state to the closed state.
    Type: Application
    Filed: May 18, 2010
    Publication date: May 12, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Koichi SATO, Masaaki TOKUNAGA
  • Publication number: 20110110685
    Abstract: An image forming apparatus includes: an image carrier carrying a toner image; a transfer unit including: a transfer body transferring the toner image onto a recording medium; and a positioning portion positioning the transfer body with respect to the image carrier; a guide portion guiding the recording medium to a position where the toner image is to be transferred onto the recording medium; and an opening and closing unit supporting the transfer unit and the guide portion and provided to be openable and closable by rotating with respect to a main body of the apparatus about a predetermined rotation center, the opening and closing unit forming different angles with the main body between when a force required to position the transfer unit with respect to the main body reaches a maximum value, and when a force required to position the guide portion with respect to the main body reaches a maximum value.
    Type: Application
    Filed: May 18, 2010
    Publication date: May 12, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Koichi SATO, Masaaki TOKUNAGA
  • Publication number: 20110069990
    Abstract: A transfer device includes: a transfer roll that transfers a toner image formed on an image holding body to a transfer subject medium; a first holding member that holds the transfer roll rotatably; a pressure contact member that brings, via the first holding member, the transfer roll into pressure contact with the image holding body; a second holding member that holds the first holding member swingably and movably; and a pressing member that produces a pressing force for bringing the pressure contact member into pressure contact with the first holding member and the second holding member in a state that the first holding member is inclined from the second holding member.
    Type: Application
    Filed: March 12, 2010
    Publication date: March 24, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masaaki TOKUNAGA, Koichi SATO
  • Patent number: 7844199
    Abstract: An image forming apparatus includes: an apparatus body including: an image forming unit that forms toner images having the colors being different from each other; a intermediate transfer body that has a belt-shape, and that is arranged in an upper portion of the image forming unit being inclined with respect to the horizontal direction, the toner images being transferred onto the intermediate transfer body; an intermediate transfer body unit that detachably holds the intermediate transfer body with respect to the apparatus body; and a guide rail member that detachably guides the intermediate transfer body unit in a direction of one side of the apparatus body, and that is set so that the direction, in which the intermediate transfer body unit is guided, is changed in the middle of guiding.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: November 30, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shiroh Suzuki, Kazuyoshi Hagiwara, Masaaki Tokunaga, Yousuke Hasegawa
  • Publication number: 20100232851
    Abstract: A developer-conveying apparatus is provided, the developer-conveying apparatus including: a conveying member that has a rotational axis rotatably set in a container and a blade formed around the rotational axis, the conveying member conveying a developer along the rotational axis by rotation; and a static eliminating member set in the container and eliminating static electricity of the developer in the container by being brought into contact with the developer.
    Type: Application
    Filed: August 28, 2009
    Publication date: September 16, 2010
    Inventors: Kazumi Yamanaka, Yoshihiro Enomoto, Masaaki Tokunaga, Hirofumi Goto, Shinichi Kawamata, Hiroaki Yagi, Masakazu Shirai
  • Publication number: 20090123196
    Abstract: An image forming apparatus includes: an endless intermediate transferring belt to which a toner image is transferred; a reference position marking member that is formed on a surface of the intermediate transferring belt, and that shows a reference position in a circumferential direction of the intermediate transferring belt; a detecting unit that detects the reference position marking member; and a control unit that controls the intermediate transferring belt to stop at a position where the reference position marking member is exposed to outside in a case where an outer cover is opened.
    Type: Application
    Filed: May 14, 2008
    Publication date: May 14, 2009
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yoshihisa NAKAO, Masao OHKUBO, Yoshihiro ENOMOTO, Shinichi KAWAMATA, Kazumi YAMANAKA, Masaaki TOKUNAGA, Hirofumi GOTO, Kazuyoshi HAGIWARA, Hiroaki YAGI, Masatoshi YAMADA
  • Publication number: 20090123178
    Abstract: An image forming apparatus includes: an apparatus body including: an image forming unit that forms toner images having the colors being different from each other; a intermediate transfer body that has a belt-shape, and that is arranged in an upper portion of the image forming unit being inclined with respect to the horizontal direction, the toner images being transferred onto the intermediate transfer body; an intermediate transfer body unit that detachably holds the intermediate transfer body with respect to the apparatus body; and a guide rail member that detachably guides the intermediate transfer body unit in a direction of one side of the apparatus body, and that is set so that the direction, in which the intermediate transfer body unit is guided, is changed in the middle of guiding.
    Type: Application
    Filed: May 13, 2008
    Publication date: May 14, 2009
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Shiroh SUZUKI, Kazuyoshi HAGIWARA, Masaaki TOKUNAGA, Yousuke HASEGAWA
  • Patent number: 6571073
    Abstract: There are plural subunits having a positional relationship that at least one of the subunits is located at such a position as to obstruct an operation of replacing another. There are provided positioning portions that are provided on the main body frame and position the respective subunits, and a subunit releasing mechanism that moves at least an outside subunit from a positioning and fixing position to a prescribed releasing position or a subunit fixing mechanism that holds the outside subunit at a prescribed releasing position and moves it from the released position to a prescribed, positioning and fixing position. Also provided is an axial movement prohibiting portion that prohibits in advance axial movement of a subunit before it is positioned. Further, a two-direction positioning portion is allowed to position a subunit preferentially over a one-direction positioning portion.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: May 27, 2003
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Wataru Suzuki, Atsuyuki Kitamura, Junichirou Sameshima, Masaaki Tokunaga
  • Patent number: 5822665
    Abstract: An object of the present invention is to provide an image forming apparatus capable of preventing vibration of a transfer film caused from the operation of a separating device to prevent irregular density distribution and change in the hue. The image forming apparatus according to the present invention and having: a transfer-medium holding member having a transfer film for adsorbing and carrying a transfer medium and arranged such that an image is formed on the transfer medium; an internally and upwardly pushing member movably disposed on the surface of the transfer film opposite to the surface to which the transfer medium is adsorbed; a moving device for moving the internally and upwardly pushing member by a predetermined quantity so that the internally and upwardly pushing member upwardly pushes the transfer film to deform the transfer film to separate the transfer medium from the transfer film; and a preventing device for preventing vibration of the internally and upwardly pushing member.
    Type: Grant
    Filed: May 14, 1997
    Date of Patent: October 13, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Keiji Yamamoto, Nobuyoshi Komatsu, Yoshihiro Enomoto, Masaaki Tokunaga, Satoshi Fukada, Tetsuya Fujita, Fumio Furusawa, Nobuo Hyakutake
  • Patent number: 5809391
    Abstract: An image forming apparatus includes a sheet transport channel including a registration roller for supplying a sheet that is fed from a tray to an image recording section at predetermined timing. A brake forcibly stops rotation of the registration roller. A sensor senses the occurrence of an abnormality in the paper transport channel during transport of the sheet. A controller activates the brake when the sensor has detected the abnormality. Therefore, when a POP jam occurs, sheet rushing into the cleaner due to an overrun can be reliably prevented. Also, in the case of feeding a sheet to prevent a guillotine jam, sheet rushing into the image recording section due to idle rotation of the registration roller can be prevented reliably.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: September 15, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tetsuya Fujita, Satoru Torimaru, Fumio Furusawa, Keiji Yamamoto, Masaaki Tokunaga, Hitoshi Funato, Satoshi Fukada
  • Patent number: 5758252
    Abstract: An image forming apparatus includes an image carrying body on which a toner image is created. A sheet carrying/transporting rotational body adsorbs a recording sheet to which the toner image on the image carrying body is transferred, and transports the sheet. The recording sheet is detached after transfer from the sheet carrying/transporting rotating body, and an assisting device thrusts against the non-image area of the recording sheet to limit its detachment from the sheet carrying/transporting rotating body. The image forming device can prevent transportation failure and image smudging that is otherwise generated when a thick sheet provided with a curl before it is adsorbed to a sheet carrying/transporting rotational body is detached in the curved state from the rotational body and transported to a fusing means.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: May 26, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yoshihiro Enomoto, Nobuo Hyakutake, Fumio Furusawa, Masaaki Tokunaga, Keiji Yamamoto, Tetsuya Fujita, Kazuhiko Miyazato
  • Patent number: 5737681
    Abstract: A developing device which develops an electrostatic latent image formed on an image carrier by toner, thereby forming a toner image; a transferring device which transfers the toner image to a fed transfer material; a registration device which provides a timing of feeding the transfer material; a curling device which nips the transfer material so as to produce a curl which is curved in the same direction as the transferring device; a curling control device which controls a nip operation mechanism of the curling device; and mode setting means for instructing the curling control device to operate are disclosed. In accordance with a thick sheet mode set in the mode setting means, the nip operation of the curling device is executed and a dummy transfer period in which the transfer operation of the transferring device is stopped is set.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: April 7, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Nobuo Hyakutake, Yasuo Nakamura, Fumio Furusawa, Keiji Yamamoto, Masaaki Tokunaga, Satoshi Fukada, Satoru Torimaru, Yoshihiro Enomoto, Tetsuya Fujita, Nobuyoshi Komatsu
  • Patent number: 5659863
    Abstract: An image forming apparatus capable of preventing a transfer material detecting unit from making any detection error when the surface of a transfer drum becomes opaque, and restraining transfer film replacement intervals from being shortened with a simple constitution. The image forming apparatus is provided with a transfer material detecting unit for detecting conditions in which a transfer material is conveyed on a transfer material carrier, and a transfer material peeling unit for peeling the transfer material off the transfer material carrier by contacting the surface of the transfer material carrier. At least part of the transfer material peeling unit is disposed so that it at least linearly contacts the axial surface of the transfer material carrier at the same position as that of the transfer material detecting unit in the axial direction of the transfer material carrier.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: August 19, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takashi Kawabata, Nobuo Hyakutake, Fumio Furusawa, Masaaki Tokunaga, Ryoichi Tsuruoka
  • Patent number: 5659836
    Abstract: A predetermined sheet retaining plane C for absorbing a record sheet is provided in the circumferential surface of a sheet carrier, and a low-reflectivity area which is to be partially covered with the record sheet is provided at a leading portion of the sheet retaining plane C. Reflection photosensors for detecting the reflectivity of the sheet carrier including the low-reflectivity area are disposed around the sheet carrier. Whether a record sheet is held in the sheet retaining plane C is judged on the basis of detection signals of the photosensors.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: August 19, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Nobuo Hyakutake, Fumio Furusawa, Takashi Kawabata, Masaaki Tokunaga
  • Patent number: 5617197
    Abstract: An image forming apparatus wherein a plurality of toner images having different colors from each other are successively formed on an image carrier, and the plurality of toner images formed on the image carrier are transferred to a transfer member carried on a transfer member carrier in such a condition that the plural toner images are successively overlapped with each other to thereby form an image, characterized in that the image forming apparatus comprises a pawl-shaped stripping member for stripping the transfer member from the transfer member carrier while being made in contact with a surface of the transfer member carrier at a predetermined timing; a volume electric resistance value of at least a portion of the pawl-shaped stripping member, which is made in contact with the transfer member, is selected to be greater than, or equal to 10 .OMEGA..cm, and smaller than, or equal to 10.sup.7 .OMEGA..cm; otherwise a surface electric resistance value thereof is selected to be greater than, or equal to 10 .
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: April 1, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takashi Kawabata, Nobuo Hyakutake, Fumio Furusawa, Masaaki Tokunaga, Ryoichi Tsuruoka
  • Patent number: 5594536
    Abstract: A rear end plate having openings is bonded to a rear end portion of a transfer film through urethane sponge. To attach the rear end portion of the transfer film to a coupling member of a frame of a transfer material carrying body, restricting portions of respective restricting members are fixed to the coupling member through the respective openings of the rear end plate. The restricting portions of the restricting members abut the top face of the rear end plate so as to restrict a radial movement of the rear end plate and allow its circumferential movement.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: January 14, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takashi Kawabata, Nobuo Hyakutake, Fumio Furusawa, Masaaki Tokunaga
  • Patent number: 5472525
    Abstract: Disclosed is a Nd-Fe-B system magnet having coercive force iHc of 12 KOe or more and high maximum energy product (BH)max of 42 MGOe or more.The permanent magnet consists of 28 to 32 wt. % of Nd and Dy (Dy ranges from 0.4 to 3 wt. %), 6 wt. % or less of Co, 0.5 wt. % or less of Al, 0.9 to 1.3 wt. % of B, at least one of 0.05 to 2.0 wt. % of Nb and 0.05 to 2.0 wt. % of V, 0.02 to 0.5 wt. % of Ga, Fe and unavoidable impurities, having coercive force iHc of 12 KOe or more and maximum energy product (BH)max of 42 MGOe or more.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: December 5, 1995
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masaaki Tokunaga, Shigeho Tanigawa, Masahiro Takahashi
  • Patent number: RE38021
    Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1—1000 &mgr;m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 &mgr;m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: March 11, 2003
    Assignee: Hitachi Metals, Ltd.
    Inventors: Minoru Endoh, Masaaki Tokunaga
  • Patent number: RE38042
    Abstract: A the magnetically anisotropic magnetic powder having an average particle size of 1-1000 &mgr;m and made from a magnetically anisotropic R-TM-B-Ga or R-TM-B-Ga-M alloy having an average crystal grain size of 0.01-0.5 &mgr;m, wherein R represents one or more rare earth elements including Y, TM represents Fe which may be partially substituted by Co, B boron, Ga gallium, and M one or more elements selected from the group consisting of Nb, W, V, Ta, Mo, Si, Al, Zr, Hf, P, C and Zn. This is useful for anisotropic resin-bonded magnet with high magnetic properties.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: March 25, 2003
    Assignee: Hitachi Metals, Ltd.
    Inventors: Minoru Endoh, Yasuto Nozawa, Katsunori Iwasaki, Shigeho Tanigawa, Masaaki Tokunaga