Patents by Inventor Takaaki Tawada

Takaaki Tawada 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: 11372363
    Abstract: An image forming apparatus is provided. The image forming apparatus includes an image bearer and a cleaning blade configured to remove toner particles remaining on the image bearer. The cleaning blade includes an elastic member in contact with a surface of the image bearer to remove the toner particles. The elastic member has a Martens hardness of from 3 to 8 N/mm2 when measured by a nanoindentation method with a load of 1 ?N. The toner particles comprise toner base particles and an external additive, and the external additive comprise silica particles. A liberation ratio (Xs) of the silica particles liberated from the toner particles is from 40% to 75% when measured by an ultrasonic vibration method. A proportion (R70) of the silica particles having a volume-based particle diameter of 70 nm or more in the silica particles liberated from the toner particles is from 70% to 90% by number.
    Type: Grant
    Filed: December 4, 2020
    Date of Patent: June 28, 2022
    Assignee: RICOH COMPANY, LTD.
    Inventors: Daisuke Inoue, Shinya Nakayama, Yohichi Kitagawa, Takaaki Tawada, Kenji Komito
  • Publication number: 20210173337
    Abstract: An image forming apparatus is provided. The image forming apparatus includes an image bearer and a cleaning blade configured to remove toner particles remaining on the image bearer. The cleaning blade includes an elastic member in contact with a surface of the image bearer to remove the toner particles. The elastic member has a Martens hardness of from 3 to 8 N/mm2 when measured by a nanoindentation method with a load of 1 ?N. The toner particles comprise toner base particles and an external additive, and the external additive comprise silica particles. A liberation ratio (Xs) of the silica particles liberated from the toner particles is from 40% to 75% when measured by an ultrasonic vibration method. A proportion (R70) of the silica particles having a volume-based particle diameter of 70 nm or more in the silica particles liberated from the toner particles is from 70% to 90% by number.
    Type: Application
    Filed: December 4, 2020
    Publication date: June 10, 2021
    Inventors: Daisuke INOUE, Shinya NAKAYAMA, Yohichi KITAGAWA, Takaaki TAWADA, Kenji KOMITO
  • Patent number: 10042315
    Abstract: An elastic blade includes a contact edge to contact a contact object, an edge region including the contact edge and having a thickness smaller than or equal to 0.50 mm, and a backup region different in material or property from the edge region. The backup region is adjacent to the edge region on a cross section perpendicular to a direction in which the contact edge extends. The elastic blade has a converted Martens hardness X (N/mm2) in a range of from 0.9 to 2.9. The converted Martens hardness is defined as: X = S A S A + S B × h A + S B S A + S B × h B where SA represents a cross-sectional area (mm2) of the edge region, SB represents a cross-sectional area (mm2) of the backup region, hA represents a Martens hardness (N/mm2) of the edge region, hB represents a Martens hardness (N/mm2) of the backup region, and t represents the thickness (mm) of the edge region including the contact edge.
    Type: Grant
    Filed: July 26, 2016
    Date of Patent: August 7, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
  • Patent number: 10031466
    Abstract: A cleaning blade includes: a blade having plural layers formed with elastic materials having different degrees of hardness from each other, an edge line portion of the blade being brought into contact with a surface of a cleaning target performing surface movement to remove adhering matter from the surface of the cleaning target. A cleaning layer of the plural layers including the edge line portion is impregnated with a resin or is made of an elastic material having a high degree of hardness. A permanent elongation rate of the entire blade is set at 3.0% or lower.
    Type: Grant
    Filed: July 31, 2015
    Date of Patent: July 24, 2018
    Assignee: RICOH COMPANY, LIMITED
    Inventors: Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi, Eisuke Shimizu, Yuu Sakakibara
  • Patent number: 9977396
    Abstract: An elastic blade may include an edge layer and at least one backup layer laminated on the edge layer. The edge layer may include a contact edge to contact a contact object and an opposing face to oppose the contact object, and the backup layer may be greater in elastic power than the edge layer.
    Type: Grant
    Filed: November 16, 2016
    Date of Patent: May 22, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
  • Patent number: 9904233
    Abstract: An elastic blade includes a contact edge to contact a contact object, an edge region including the contact edge, and a backup region different in at least one of material and physical property from the edge region and adjacent to the edge region on a cross section perpendicular to a direction in which the contact edge extends. The backup region is free of direct contact with the contact object. In the elastic blade, a converted elastic power X is from 57% to 90% and defined as X = S A S A + S B × e A + S B S A + S B × e B where SA and SB represent cross-sectional areas of the edge region and the backup region on the cross section, and eA and eB represent elastic powers of the edge region and the backup region.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: February 27, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
  • Patent number: 9798284
    Abstract: A multilayered blade made of an elastic material includes an edge layer, having a contact edge to contact an object, and at least one backup layer laminated on the edge layer. The blade has a converted loss tangent tan ? of 0.23 or greater and 0.51 or smaller in a temperature range of from 0° C. to 50° C. The converted loss tangent tan ? is defined as: X = A A + B × L 1 + B A + B × L 2 , where X represents the converted loss tangent tan ?, A represents a thickness in millimeters of the edge layer, B represents a thickness in millimeters of the at least one backup layer, L1 represents a variation of a loss tangent tan ? of the edge layer in the temperature range of from 0° C. to 50° C., and L2 represents a variation of a loss tangent tan ? of the at least one backup layer in the temperature range of from 0° C. to 50° C.
    Type: Grant
    Filed: March 7, 2016
    Date of Patent: October 24, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
  • Publication number: 20170199493
    Abstract: A cleaning blade includes: a blade having plural layers formed with elastic materials having different degrees of hardness from each other, an edge line portion of the blade being brought into contact with a surface of a cleaning target performing surface movement to remove adhering matter from the surface of the cleaning target. A cleaning layer of the plural layers including the edge line portion is impregnated with a resin or is made of an elastic material having a high degree of hardness. A permanent elongation rate of the entire blade is set at 3.0% or lower.
    Type: Application
    Filed: July 31, 2015
    Publication date: July 13, 2017
    Inventors: Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI, Eisuke SHIMIZU, Yuu SAKAKIBARA
  • Publication number: 20170146944
    Abstract: An elastic blade includes a contact edge to contact a contact object, an edge region including the contact edge, and a backup region different in at least one of material and physical property from the edge region and adjacent to the edge region on a cross section perpendicular to a direction in which the contact edge extends. The backup region is free of direct contact with the contact object. In the elastic blade, a converted elastic power X is from 57% to 90% and defined as X = S A S A + S B × e A + S B S A + S B × e B , where SA and SB represent cross-sectional areas of the edge region and the backup region on the cross section, eA and eB represent elastic powers of the edge region and the backup region, and t represents a thickness of the edge region in a direction perpendicular to the longer of two sides of the edge region on the cross section.
    Type: Application
    Filed: October 31, 2016
    Publication date: May 25, 2017
    Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Yuu SAKAKIBARA
  • Publication number: 20170068207
    Abstract: An elastic blade may include an edge layer and at least one backup layer laminated on the edge layer. The edge layer may include a contact edge to contact a contact object and an opposing face to oppose the contact object, and the backup layer may be greater in elastic power than the edge layer.
    Type: Application
    Filed: November 16, 2016
    Publication date: March 9, 2017
    Applicant: Ricoh Company, Ltd.
    Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI, Shimizu EISUKE
  • Publication number: 20170038724
    Abstract: An elastic blade includes a contact edge to contact a contact object, an edge region including the contact edge and having a thickness smaller than or equal to 0.50 mm, and a backup region different in material or property from the edge region. The backup region is adjacent to the edge region on a cross section perpendicular to a direction in which the contact edge extends. The elastic blade has a converted Martens hardness X (N/mm2) in a range of from 0.9 to 2.9. The converted Martens hardness is defined as: X = S A S A + S B × h A + S B S A + S B × h B where SA represents a cross-sectional area (mm2) of the edge region, SB represents a cross-sectional area (mm2) of the backup region, hA represents a Martens hardness (N/mm2) of the edge region, hB represents a Martens hardness (N/mm2) of the backup region, and t represents the thickness (mm) of the edge region including the contact edge.
    Type: Application
    Filed: July 26, 2016
    Publication date: February 9, 2017
    Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Yuu SAKAKIBARA
  • Patent number: 9529317
    Abstract: An elastic blade includes an edge layer and at least one backup layer laminated on the edge layer. The edge layer includes a contact edge to contact a contact object and an opposing face to oppose the contact object, and the backup layer is greater in elastic power than the edge layer.
    Type: Grant
    Filed: September 18, 2015
    Date of Patent: December 27, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
  • Publication number: 20160320738
    Abstract: A photoconductor cleaning device includes a photoconductor, a cleaner, and a roller. The cleaner is disposed in contact with the photoconductor to remove adhered substances on a surface of the photoconductor. The charger charges the photoconductor. The roller is disposed between the cleaner and the charger to remove adhered substances on the surface of the photoconductor.
    Type: Application
    Filed: April 26, 2016
    Publication date: November 3, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Takaaki TAWADA, Kazuhiko WATANABE, Yuu SAKAKIBARA, Eisuke SHIMIZU, Takuya SEKINE, Ryuji YOSHIDA
  • Publication number: 20160259293
    Abstract: A multilayered blade made of an elastic material includes an edge layer, having a contact edge to contact an object, and at least one backup layer laminated on the edge layer. The blade has a converted loss tangent tan ? of 0.23 or greater and 0.51 or smaller in a temperature range of from 0° C. to 50° C. The converted loss tangent tan ? is defined as: X = A A + B × L 1 + B A + B × L 2 , where X represents the converted loss tangent tan ?, A represents a thickness in millimeters of the edge layer, B represents a thickness in millimeters of the at least one backup layer, L1 represents a variation of a loss tangent tan ? of the edge layer in the temperature range of from 0° C. to 50° C., and L2 represents a variation of a loss tangent tan ? of the at least one backup layer in the temperature range of from 0° C. to 50° C.
    Type: Application
    Filed: March 7, 2016
    Publication date: September 8, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Eisuke SHIMIZU, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
  • Patent number: 9436117
    Abstract: An image forming apparatus, includes an image carrier; a power supply; a charging member, to which the power supply applies a direct current (DC) charging voltage, to charge a surface of the image carrier; and a controller. The controller causes the power supply to apply, to the charging member, the DC charging voltage of a sum of a reference voltage VC and a correction amount ?, so that a charged potential VD of the surface of the image carrier assumes a target value that is substantially equal to the reference voltage VC; and to increase an absolute value of the correction amount ? to be added to the reference voltage VC in inverse proportion to an absolute value of the reference voltage VC, when the absolute value of the reference voltage VC is smaller compared to a case in which the absolute value of the reference voltage VC is greater.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: September 6, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Kikuchi, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu
  • Patent number: 9329519
    Abstract: A charging roller to apply voltage to a target to charge the target has a surface having a color set in one of a range according to CIE L*a*b* color space and a range according to CIE XYZ color space, and the range according to CIE L*a*b* color space is defined as 32.6?L*?50.9, 0.51?a*?1.12, and 6.0?b*?8.4; and the range according to CIE XYZ color space is defined as 8.8?X?21.0, 9.1?Y?21.3, and 5.7?Z?11.8.
    Type: Grant
    Filed: June 3, 2015
    Date of Patent: May 3, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hisashi Kikuchi, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu
  • Publication number: 20160109846
    Abstract: An elastic blade includes an edge layer and at least one backup layer laminated on the edge layer. The edge layer includes a contact edge to contact a contact object and an opposing face to oppose the contact object, and the backup layer is greater in elastic power than the edge layer.
    Type: Application
    Filed: September 18, 2015
    Publication date: April 21, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI
  • Patent number: 9310750
    Abstract: An image forming apparatus includes a rotatable image bearer, a charging member to contact a surface of the image bearer and charge the image bearer, an exposure device to expose the image bearer and form a latent image, a developing device to develop the latent image on the image bearer into a toner image, a transfer device to transfer the toner image from the image bearer onto a transfer medium, and a cleaning blade to contact the surface of the image bearer and remove toner from the image bearer after image transfer. The charging member has surface unevenness created by projections and recesses extending in a direction of rotation of the image bearer. The cleaning blade is configured to abrade projections formed on the surface of the image bearer.
    Type: Grant
    Filed: October 10, 2013
    Date of Patent: April 12, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Kikuchi, Takatsugu Fujishiro, Kazuhiko Watanabe, Takaaki Tawada, Naomi Sugimoto, Yuu Sakakibara
  • Patent number: 9310751
    Abstract: A blade includes an elastic member including a tip ridgeline to contact the surface of a member to contact. The tip ridgeline includes an impregnation layer impregnated with a cured compound comprising an acrylate or methacrylate compound having an alicyclic structure including 6 or more carbon atoms in its molecule, and has an elastic power in the range of 50% to 80%.
    Type: Grant
    Filed: June 4, 2015
    Date of Patent: April 12, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
  • Publication number: 20160097987
    Abstract: An image forming apparatus, includes an image carrier; a power supply; a charging member, to which the power supply applies a direct current (DC) charging voltage, to charge a surface of the image carrier; and a controller. The controller causes the power supply to apply, to the charging member, the DC charging voltage of a sum of a reference voltage VC and a correction amount ?, so that a charged potential VD of the surface of the image carrier assumes a target value that is substantially equal to the reference voltage VC; and to increase an absolute value of the correction amount ? to be added to the reference voltage VC in inverse proportion to an absolute value of the reference voltage VC, when the absolute value of the reference voltage VC is smaller compared to a case in which the absolute value of the reference voltage VC is greater.
    Type: Application
    Filed: September 17, 2015
    Publication date: April 7, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Hisashi KIKUCHI, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu