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).
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Patent number: 11372363Abstract: 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: GrantFiled: December 4, 2020Date of Patent: June 28, 2022Assignee: RICOH COMPANY, LTD.Inventors: Daisuke Inoue, Shinya Nakayama, Yohichi Kitagawa, Takaaki Tawada, Kenji Komito
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Publication number: 20210173337Abstract: 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: ApplicationFiled: December 4, 2020Publication date: June 10, 2021Inventors: Daisuke INOUE, Shinya NAKAYAMA, Yohichi KITAGAWA, Takaaki TAWADA, Kenji KOMITO
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Patent number: 10042315Abstract: 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: GrantFiled: July 26, 2016Date of Patent: August 7, 2018Assignee: Ricoh Company, Ltd.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
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Patent number: 10031466Abstract: 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: GrantFiled: July 31, 2015Date of Patent: July 24, 2018Assignee: RICOH COMPANY, LIMITEDInventors: Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi, Eisuke Shimizu, Yuu Sakakibara
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Patent number: 9977396Abstract: 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: GrantFiled: November 16, 2016Date of Patent: May 22, 2018Assignee: Ricoh Company, Ltd.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
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Patent number: 9904233Abstract: 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: GrantFiled: October 31, 2016Date of Patent: February 27, 2018Assignee: Ricoh Company, Ltd.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
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Patent number: 9798284Abstract: 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: GrantFiled: March 7, 2016Date of Patent: October 24, 2017Assignee: RICOH COMPANY, LTD.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
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Publication number: 20170199493Abstract: 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: ApplicationFiled: July 31, 2015Publication date: July 13, 2017Inventors: Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI, Eisuke SHIMIZU, Yuu SAKAKIBARA
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Publication number: 20170146944Abstract: 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: ApplicationFiled: October 31, 2016Publication date: May 25, 2017Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Yuu SAKAKIBARA
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Publication number: 20170068207Abstract: 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: ApplicationFiled: November 16, 2016Publication date: March 9, 2017Applicant: Ricoh Company, Ltd.Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI, Shimizu EISUKE
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Publication number: 20170038724Abstract: 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: ApplicationFiled: July 26, 2016Publication date: February 9, 2017Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Yuu SAKAKIBARA
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Patent number: 9529317Abstract: 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: GrantFiled: September 18, 2015Date of Patent: December 27, 2016Assignee: RICOH COMPANY, LTD.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
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Publication number: 20160320738Abstract: 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: ApplicationFiled: April 26, 2016Publication date: November 3, 2016Applicant: Ricoh Company, Ltd.Inventors: Takaaki TAWADA, Kazuhiko WATANABE, Yuu SAKAKIBARA, Eisuke SHIMIZU, Takuya SEKINE, Ryuji YOSHIDA
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Publication number: 20160259293Abstract: 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: ApplicationFiled: March 7, 2016Publication date: September 8, 2016Applicant: Ricoh Company, Ltd.Inventors: Eisuke SHIMIZU, Kazuhiko Watanabe, Takaaki Tawada, Yuu Sakakibara
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Patent number: 9436117Abstract: 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: GrantFiled: September 17, 2015Date of Patent: September 6, 2016Assignee: Ricoh Company, Ltd.Inventors: Hisashi Kikuchi, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu
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Patent number: 9329519Abstract: 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: GrantFiled: June 3, 2015Date of Patent: May 3, 2016Assignee: RICOH COMPANY, LTD.Inventors: Hisashi Kikuchi, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu
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Publication number: 20160109846Abstract: 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: ApplicationFiled: September 18, 2015Publication date: April 21, 2016Applicant: Ricoh Company, Ltd.Inventors: Eisuke SHIMIZU, Kazuhiko WATANABE, Takaaki TAWADA, Hisashi KIKUCHI
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Patent number: 9310750Abstract: 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: GrantFiled: October 10, 2013Date of Patent: April 12, 2016Assignee: Ricoh Company, Ltd.Inventors: Hisashi Kikuchi, Takatsugu Fujishiro, Kazuhiko Watanabe, Takaaki Tawada, Naomi Sugimoto, Yuu Sakakibara
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Patent number: 9310751Abstract: 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: GrantFiled: June 4, 2015Date of Patent: April 12, 2016Assignee: Ricoh Company, Ltd.Inventors: Eisuke Shimizu, Kazuhiko Watanabe, Takaaki Tawada, Hisashi Kikuchi
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Publication number: 20160097987Abstract: 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: ApplicationFiled: September 17, 2015Publication date: April 7, 2016Applicant: Ricoh Company, Ltd.Inventors: Hisashi KIKUCHI, Kazuhiko Watanabe, Takaaki Tawada, Eisuke Shimizu