Patents by Inventor Tetsumaru Fujita

Tetsumaru Fujita 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: 10036976
    Abstract: A developing device includes a developer bearer facing a latent image bearer, to rotate and supply developer to the latent image bearer, and a developer regulator to regulate an amount of the developer on a surface of the developer bearer. The developer regulator is in contact with the surface of the developer bearer. In the developing device, a ratio of a ten-point mean roughness of the developer regulator to a volume average particle diameter of the developer is not greater than 3.5%. The ratio is defined as Rzjis/Dv×100, where Rzjis represents the ten-point mean roughness measured in a nip-adjacent portion of a face of the developer regulator opposing the developer bearer, and Dv represents the volume average particle diameter of the developer. The nip-adjacent portion is adjacent to and downstream a downstream end of a regulation nip in a rotation direction of the developer bearer.
    Type: Grant
    Filed: December 2, 2016
    Date of Patent: July 31, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuji Nagatomo, Tetsumaru Fujita, Masato Tsuji, Yutaro Kaku
  • Patent number: 9958806
    Abstract: A developing device includes a toner bearer to rotate while bearing toner and a toner regulator including a bend on a free end side. The bend is disposed in contact with a surface of the toner bearer and defines a regulation nip to adjust an amount of the toner on the toner bearer. The toner regulator further includes an area having a water contact angle greater than or equal to 70 degrees. The area having the water contact angle includes, at least, a downstream end of the bend in a rotation direction of the toner bearer.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: May 1, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masato Tsuji, Tetsumaru Fujita, Yuji Nagatomo, Mitsutoshi Kichise, Yutaro Kaku, Kazuki Matsumoto
  • Publication number: 20170176886
    Abstract: A developing device includes a developer bearer facing a latent image bearer, to rotate and supply developer to the latent image bearer, and a developer regulator to regulate an amount of the developer on a surface of the developer bearer. The developer regulator is in contact with the surface of the developer bearer. In the developing device, a ratio of a ten-point mean roughness of the developer regulator to a volume average particle diameter of the developer is not greater than 3.5%. The ratio is defined as Rzjis/Dv×100, where Rzjis represents the ten-point mean roughness measured in a nip-adjacent portion of a face of the developer regulator opposing the developer bearer, and Dv represents the volume average particle diameter of the developer. The nip-adjacent portion is adjacent to and downstream a downstream end of a regulation nip in a rotation direction of the developer bearer.
    Type: Application
    Filed: December 2, 2016
    Publication date: June 22, 2017
    Applicant: Ricoh Company, Ltd.
    Inventors: Yuji NAGATOMO, Tetsumaru Fujita, Masato Tsuji, Yutaro Kaku
  • Publication number: 20170146925
    Abstract: A developing device includes a toner bearer to rotate while bearing toner and a toner regulator including a bend on a free end side. The bend is disposed in contact with a surface of the toner bearer and defines a regulation nip to adjust an amount of the toner on the toner bearer. The toner regulator further includes an area having a water contact angle greater than or equal to 70 degrees. The area having the water contact angle includes, at least, a downstream end of the bend in a rotation direction of the toner bearer.
    Type: Application
    Filed: November 8, 2016
    Publication date: May 25, 2017
    Inventors: Masato TSUJI, Tetsumaru FUJITA, Yuji NAGATOMO, Mitsutoshi KICHISE, Yutaro KAKU, Kazuki MATSUMOTO
  • Patent number: 9201393
    Abstract: A toner container includes a substantially tetrahedral toner-containing portion having an openable edge to discharge toner contained in the toner-containing portion, and a reference fold along which the toner container is foldable after the openable edge is opened. The reference fold extends from the openable edge and is provided on medians of two triangular faces of the toner-containing portion adjoining each other along the openable edge.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: December 1, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuusuke Furuichi, Rie Mitani, Takafumi Miyazaki, Hidekazu Shono, Osamu Saito, Ryuji Inoue, Tetsumaru Fujita, Kei Hasegawa, Yasuhide Ohkubo, Tomofumi Yoshida, Shintaro Yamada, Yoshihiro Fukuhata, Ryouhei Ohi
  • Patent number: 9014593
    Abstract: A sealing assembly to contact a rotator includes a sealing member to slidably contact a surface of an end of the rotator in an axial direction of the rotator. The sealing member has an end in a circumferential direction thereof to contact the surface of the rotator with a first pressure. The end in the circumferential direction is fixed to a bearing surface formed on the opening on at least one of an upstream side and a downstream side in a rotation direction of the rotator. The sealing member has an intermediate portion between an upstream end and a downstream end in the circumferential direction to contact the surface of the rotator with a second pressure lower than the first pressure.
    Type: Grant
    Filed: November 20, 2013
    Date of Patent: April 21, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasunobu Ogata, Tetsumaru Fujita, Rie Mitani, Takahiro Sanada
  • Patent number: 9002243
    Abstract: A developing device includes a toner bearer including a surface in which multiple recesses having a cross-sectional void rate of 50% or smaller are formed, a toner supply member to supply toner to the toner bearer, and a developer regulator disposed facing or in contact with the toner bearer and including a bent tip portion. The toner bearer has a surface roughness Ra within a range from 1.0 ?m to 2.0 ?m, and a surface area ratio within a range from 2.0 to 4.0. The developing device uses polymerized toner having a weight average particle diameter of 8.0 ?m or smaller and an average circularity of 0.98 or greater.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: April 7, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsumaru Fujita, Ryuji Inoue, Rie Mitani
  • Publication number: 20150063865
    Abstract: A toner container includes a substantially tetrahedral toner-containing portion having an openable edge to discharge toner contained in the toner-containing portion, and a reference fold along which the toner container is foldable after the openable edge is opened. The reference fold extends from the openable edge and is provided on medians of two triangular faces of the toner-containing portion adjoining each other along the openable edge.
    Type: Application
    Filed: July 21, 2014
    Publication date: March 5, 2015
    Inventors: Yuusuke FURUICHI, Rie MITANI, Takafumi MIYAZAKI, Hidekazu SHONO, Osamu SAITO, Ryuji INOUE, Tetsumaru FUJITA, Kei HASEGAWA, Yasuhide OHKUBO, Tomofumi YOSHIDA, Shintaro YAMADA, Yoshihiro FUKUHATA, Ryouhei OHI
  • Publication number: 20140270861
    Abstract: A developing device includes a toner bearer including a surface in which multiple recesses having a cross-sectional void rate of 50% or smaller are formed, a toner supply member to supply toner to the toner bearer, and a developer regulator disposed facing or in contact with the toner bearer and including a bent tip portion. The toner bearer has a surface roughness Ra within a range from 1.0 ?m to 2.0 ?m, and a surface area ratio within a range from 2.0 to 4.0. The developing device uses polymerized toner having a weight average particle diameter of 8.0 ?m or smaller and an average circularity of 0.98 or greater.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 18, 2014
    Inventors: Tetsumaru FUJITA, Ryuji Inoue, Rie Mitani
  • Publication number: 20140153958
    Abstract: A sealing assembly to contact a rotator includes a sealing member to slidably contact a surface of an end of the rotator in an axial direction of the rotator. The sealing member has an end in a circumferential direction thereof to contact the surface of the rotator with a first pressure. The end in the circumferential direction is fixed to a bearing surface formed on the opening on at least one of an upstream side and a downstream side in a rotation direction of the rotator. The sealing member has an intermediate portion between an upstream end and a downstream end in the circumferential direction to contact the surface of the rotator with a second pressure lower than the first pressure.
    Type: Application
    Filed: November 20, 2013
    Publication date: June 5, 2014
    Inventors: Yasunobu OGATA, Tetsumaru Fujita, Rie Mitani, Takahiro Sanada
  • Patent number: 8688015
    Abstract: A development device includes a developer carrier configured to carry on a surface thereof a developer, the developer carrier being disposed to face a latent image carrier, a developer tank having the developer carrier, a developer container configured to house the developer to be supplied to the developer tank, the developer container being connected to the developer tank through a partition having an opening, and a developer carrier member configured to carry the developer in the developer container, the developer being supplied to the developer tank from the opening while being carried by the developer carrier member, and the amount of developer to be supplied to the developer tank from the opening being gradually increased in a developer carrying direction of the developer carrier member.
    Type: Grant
    Filed: August 2, 2011
    Date of Patent: April 1, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsumaru Fujita, Kohta Sakaya
  • Patent number: 8594519
    Abstract: A toner supplying method for supplying toner from a toner container to a developing part that causes toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, includes detecting a toner amount in the developing part as being equal to or less than a predetermined toner amount value; forming a fog detecting image in a case where the toner amount in the developing part is equal to or less than the predetermined toner amount value, and detecting fog; and determining based on the detected fog whether to execute a toner ejecting process of ejecting the toner remaining in the developing part toward the latent image carrying member before supplying the toner to the developing part from the toner container.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: November 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoki Nakatake, Atsushi Takehara, Tetsumaru Fujita, Tomohiro Kubota, Kohta Sakaya
  • Patent number: 8503892
    Abstract: A developing unit includes: a developer carrier; a toner supplying member having a porous surface layer; a toner storage storing therein toner; a stirring member that is rotated to stir the toner; a toner amount detecting unit that detects an amount of the toner; a toner supplying unit that supplies new toner to the toner storage based on a detection result; and a toner removing member that removes the toner carried in the porous surface layer, wherein the toner removing member is arranged in a separable and contactable manner from and with the porous surface layer, and the developing unit has a stirring mode in which the toner removing member is brought into contact with the porous surface layer, and the toner supplying member is rotated while the stirring member is rotated to stir the toner.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: August 6, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Kohta Sakaya, Tomohiro Kubota, Tetsumaru Fujita, Atsushi Takehara, Naoki Nakatake
  • Patent number: 8483583
    Abstract: Toner is supplied from a toner container to a developing part that causes the toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, a pre-toner-supply operation of supplying a predetermined amount of toner to the developing part is carried out, a fog detecting image is formed and fog is detected in the fog detecting image, a toner supply amount to be supplied to the developing part is determined based on the fog detected in the detecting and an operational status of the developing part since the toner was supplied to the developing part the last time, and the toner supply amount of the toner determined in the determining is supplied to the developing part.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: July 9, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takehara, Naoki Nakatake, Tetsumaru Fujita, Tomohiro Kubota, Kohta Sakaya
  • Patent number: 8452216
    Abstract: An image forming apparatus includes an image carrier on which a latent image is formed, a charging device that charges the image carrier, an exposing device that irradiates the image carrier, thereby forming a latent image on the image carrier, a developing device that develops the latent image into a visible image by using a monocomponent developer that is carried and transferred by a developer carrier and that is charged to a predetermined polarity, and a toner supply container that is installed in the developing device for toner supply. Used old toner is conveyed from the developing device to the toner supply container and mixed with unused new toner within the toner supply container and thus a mixed toner is produced, and the mixed toner is supplied to the developing device.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: May 28, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Tetsumaru Fujita, Atsushi Takehara, Naoki Nakatake
  • Patent number: 8406664
    Abstract: An image forming apparatus includes a plurality of image carriers, a latent image forming unit, and a plurality of developing units. Each of the developing unit forms an image to have a color difference of equal to or less than about five with respect to an initial unicolor image formed by using a toner not containing a reversely-transferred toner of another color when a toner contained in a toner container is consumed by about 70%.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: March 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsumaru Fujita, Yuji Nagatomo
  • Patent number: 8354164
    Abstract: A semiconductive member including an alkali metal salt having the formula (M)n.X in a surface layer thereof. M represents Na+, K+, or Li+; X represents Cl?, Br?, I?, F?, CH3COO?, CF3COO?, CH(COOH)CHCOO?, (CHCOO?)2, CH2(COOH)CH2COO?, (CH2COO?)2, (HOOC)Ar(COO?), Ar(COO?)2, (HOOC)2Ar(COO?), (HOOC)Ar(COO?)2, Ar(COO?)3, (HOOC)3Ar(COO?), (HOOC)2Ar(COO?)2, (HOOC)Ar(COO?)3, Ar(COO?)4, Ar—SO3?, Ar(SO3?)2, an oligomer or a polymer having an acrylic acid anion unit, or an oligomer or a polymer having an methacrylic acid anion unit; Ar represents a benzene ring, a naphthalene ring, or a biphenyl ring; and n is a numeral equivalent to the anionic valence of X.
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: January 15, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Chiyoshi Nozaki, Tetsumaru Fujita, Shintaro Yamada, Yuji Nagatomo, Shin Murayama, Manabu Hamada, Yoshimichi Ishikawa
  • Publication number: 20120033997
    Abstract: A development device includes a developer carrier configured to carry on a surface thereof a developer, the developer carrier being disposed to face a latent image carrier, a developer tank having the developer carrier, a developer container configured to house the developer to be supplied to the developer tank, the developer container being connected to the developer tank through a partition having an opening, and a developer carrier member configured to carry the developer in the developer container, the developer being supplied to the developer tank from the opening while being carried by the developer carrier member, and the amount of developer to be supplied to the developer tank from the opening being gradually increased in a developer carrying direction of the developer carrier member.
    Type: Application
    Filed: August 2, 2011
    Publication date: February 9, 2012
    Inventors: Tetsumaru FUJITA, Kohta Sakaya
  • Patent number: 8036573
    Abstract: An image forming apparatus includes an image carrying member, an image writing unit, a development unit, a transfer device, a charging device, and a toner charge control device. The image writing unit forms a latent image on the image carrying member, which is developed as a toner image by the development unit, and the toner image is transferred to a transfer member by the transfer device. The charging device charges the image carrying member and toner on the image carrying member. The toner charge control device, controls a polarity of charge and charging voltage level of toner remaining on the image carrying member. The toner charge control device includes an endless belt having a surface made of a conductive material, a support member extending the endless belt pressed against the image carrying member, and a bias voltage applicator for supplying a voltage to the surface of the endless belt.
    Type: Grant
    Filed: August 6, 2008
    Date of Patent: October 11, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidekazu Shono, Naoki Nakatake, Tetsumaru Fujita
  • Publication number: 20110217055
    Abstract: Toner is supplied from a toner container to a developing part that causes the toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, a pre-toner-supply operation of supplying a predetermined amount of toner to the developing part is carried out, a fog detecting image is formed and fog is detected in the fog detecting image, a toner supply amount to be supplied to the developing part is determined based on the fog detected in the detecting and an operational status of the developing part since the toner was supplied to the developing part the last time, and the toner supply amount of the toner determined in the determining is supplied to the developing part.
    Type: Application
    Filed: February 11, 2011
    Publication date: September 8, 2011
    Inventors: Atsushi TAKEHARA, Naoki Nakatake, Tetsumaru Fujita, Tomohiro Kubota, Kohta Sakaya