Patents by Inventor Yuka Ishihara

Yuka Ishihara 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: 20220373914
    Abstract: An electrostatic charge image developing toner contains: a toner particle including a core portion containing a binder resin and a release agent that has a melting temperature Tm of 80° C. or less, and a coating layer that coats the core portion and contains an amorphous polyester resin, and the toner particle has a cross section in which one or more and three or less domains of the release agent are present in the core portion, the one or more and three or less domains having a circle-equivalent diameter of 1 ?m or more and 3 ?m or less, the toner particle has a volume average particle diameter of 4.2 ?m or more and 5.8 ?m or less, and a ratio of a thickness of the coating layer to a maximum diameter of the toner particle is 1% or more and 25% or less in the cross section.
    Type: Application
    Filed: August 17, 2021
    Publication date: November 24, 2022
    Applicant: FUJIFILM Business Innovation Corp.
    Inventors: Masashi IKEDA, Yuka ISHIHARA, Akira MATSUMOTO
  • Publication number: 20220244653
    Abstract: A unit includes: a developing device configured to develop an electrostatic charge image that is formed on a surface of an image carrier, as a toner image with a developer including a brilliant toner containing a flat brilliant pigment, the developer being accommodated in the developing device; and a fixing device configured to fix the toner image onto a surface of a recording medium at a fixing temperature of 130° C. or higher and 230° C. or lower that includes a fixing belt, a first roller and a second roller that are disposed inside the fixing belt and support the fixing belt while applying tension to the fixing belt, and a pressure roller, the first roller and the pressure roller sandwiching the fixing belt to form a nip portion.
    Type: Application
    Filed: August 23, 2021
    Publication date: August 4, 2022
    Applicant: FUJIFILM Business Innovation Corp.
    Inventors: Yukiko KAMIJO, Hideaki OHARA, Kenji OMORI, Junko YAMASAKI, Daisuke NAKASHIMA, Yuka ISHIHARA, Hitoshi KOMURO
  • Patent number: 10067437
    Abstract: An electrostatic charge image developer includes: toner particles; silica particles treated with a silicone oil, which are externally added to the toner particles; and a carrier, wherein a volume average particle diameter of the carrier is equal to or greater than 20 ?m and smaller than 30 ?m, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier (silicone oil-derived elemental silicon/silica-derived elemental silicon) is in a range of 0.05 to 0.2.
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: September 4, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Masashi Ikeda, Emi Takahashi, Yuka Ishihara, Manabu Furuki, Makoto Kamisaki, Teppei Yawada
  • Patent number: 9891577
    Abstract: An image forming apparatus includes a charging unit that includes a conductive member which contacts with a surface of an image holding member, and that applies only a DC voltage to the conductive member to charge the surface of the image holding member; and a cleaning unit that has a blade which contacts with the surface of an image holding member and cleans the surface with the blade after a toner image is transferred onto a recording medium, wherein a developer includes toner particles, silica particles treated with a silicone oil, and a carrier, a volume average particle diameter of the carrier is from 20 ?m to 35 ?m, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier is from 0.05 to 0.2.
    Type: Grant
    Filed: October 25, 2016
    Date of Patent: February 13, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Masashi Ikeda, Emi Takahashi, Yuka Ishihara, Manabu Furuki, Makoto Kamisaki, Teppei Yawada
  • Publication number: 20170357205
    Abstract: An image forming apparatus includes a charging unit that includes a conductive member which contacts with a surface of an image holding member, and that applies only a DC voltage to the conductive member to charge the surface of the image holding member; and a cleaning unit that has a blade which contacts with the surface of an image holding member and cleans the surface with the blade after a toner image is transferred onto a recording medium, wherein a developer includes toner particles, silica particles treated with a silicone oil, and a carrier, a volume average particle diameter of the carrier is from 20 ?m to 35 ?m, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier is from 0.05 to 0.2.
    Type: Application
    Filed: October 25, 2016
    Publication date: December 14, 2017
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masashi IKEDA, Emi TAKAHASHI, Yuka ISHIHARA, Manabu FURUKI, Makoto KAMISAKI, Teppei YAWADA
  • Publication number: 20170357171
    Abstract: An electrostatic charge image developer includes: toner particles; silica particles treated with a silicone oil, which are externally added to the toner particles; and a carrier, wherein a volume average particle diameter of the carrier is equal to or greater than 20 ?m and smaller than 30 ?m, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier (silicone oil-derived elemental silicon/silica-derived elemental silicon) is in a range of 0.05 to 0.2.
    Type: Application
    Filed: November 1, 2016
    Publication date: December 14, 2017
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masashi IKEDA, Emi TAKAHASHI, Yuka ISHIHARA, Manabu FURUKI, Makoto KAMISAKI, Teppei YAWADA
  • Publication number: 20170269499
    Abstract: An image forming method includes developing an electrostatic charge image on the surface of an image holding member by a developer including toner particles which contain a binder resin, a flake shape brilliant pigment, and a layered inorganic material, transferring the developed toner image onto a surface of a recording medium, and fixing the toner image, which is a brilliant image, by passing the recording medium through a contact region between a fixing member and a pressing member pressed to the fixing member, the brilliant image satisfying (1) at a depth of 200 nm, A<10, 10?B?50, and 20?C?70 and (2) at a depth of 1,000 nm, 10?A?40, 20?B?60, and 20?C?50, wherein A, B and C are element amounts (atomic %) of aluminium, silicon, and carbon, respectively.
    Type: Application
    Filed: August 18, 2016
    Publication date: September 21, 2017
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuka ISHIHARA, Satomi HARA, Masaru TAKAHASHI, Masahiro TAKAYAMA
  • Patent number: 8685602
    Abstract: There is provided a toner for electrophotography containing at least a binder resin, a colorant and a barium compound, and having a relaxation modulus G(t) of from about 2.0×102 Pa to about 3.0×103 Pa in a relaxation time of t=10×Dt (wherein Dt is the heating time taken during fixing) as determined by the measurement of dynamic viscoelasticity, and a barium content of from about 0.1% to about 0.5% with respect to the total amount of constituent atoms in the toner as determined by X-ray fluorescence.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: April 1, 2014
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yuka Ishihara, Emi Takahashi, Masahiro Okita
  • Patent number: 8501380
    Abstract: An electrostatic latent image developing toner includes a mother particle which contains a coloring agent, a release agent and a binder resin; and an inorganic particle which is added to the surface of the mother particle, and wherein a relation between a relaxation time t and a relaxation modulus G(t) which are determined from the dynamic viscoelasticity measurement made on the toner satisfies the following equations (1) and (2); G(t1)<100 Pa??(1) 515<(G(t2)?G(t1))/(log(t1)?log(t2))<1,230??(2) wherein t1 represents the maximum relaxation time and t2 represents the minimum relaxation time.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: August 6, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yuka Ishihara, Masaki Nakamura, Satoshi Inoue, Katsumi Daimon
  • Publication number: 20120251935
    Abstract: There is provided a toner for electrophotography containing at least a binder resin, a colorant and a barium compound, and having a relaxation modulus G(t) of from about 2.0×102 Pa to about 3.0×103 Pa in a relaxation time of t=10×Dt (wherein Dt is the heating time taken during fixing) as determined by the measurement of dynamic viscoelasticity, and a barium content of from about 0.1% to about 0.5% with respect to the total amount of constituent atoms in the toner as determined by X-ray fluorescence.
    Type: Application
    Filed: August 16, 2011
    Publication date: October 4, 2012
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuka ISHIHARA, Emi TAKAHASHI, Masahiro OKITA
  • Publication number: 20110236812
    Abstract: An electrostatic latent image developing toner includes a mother particle which contains a coloring agent, a release agent and a binder resin; and an inorganic particle which is added to the surface of the mother particle, and wherein a relation between a relaxation time t and a relaxation modulus G(t) which are determined from the dynamic viscoelasticity measurement made on the toner satisfies the following equations (1) and (2); G(t1)<100 Pa??(1) 515<(G(t2)?G(t1))/(log(t1)?log(t2))<1,230??(2) wherein t1 represents the maximum relaxation time and t2 represents the minimum relaxation time.
    Type: Application
    Filed: August 17, 2010
    Publication date: September 29, 2011
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yuka ISHIHARA, Masaki NAKAMURA, Satoshi INOUE, Katsumi DAIMON
  • Patent number: 7713669
    Abstract: A toner for developing electrostatic images, comprising a binder resin and a colorant, the binder resin including a crystalline polyester resin and an amorphous resin. When, in differential scanning calorimetry of the toner according to ASTM D3418-8, the temperature of the endothermic peak derived from the crystalline polyester resin in a first heating process is defined as Tm1 (° C.), the endothermic quantity based on the endothermic peak in the first heating process is defined as ?H1 (mW/g), and the endothermic quantity based on the endothermic peak in a second heating process is defined as ?H2 (mW/g), Tm1 is 50 to 80° C., and ?H1 and ?H2 satisfy the relationship represented by the following Formula (1). When the softening temperature of the toner is defined as Tf1/2 (° C.), Tf1/2 is 85 to 135° C. Tm1 and Tf1/2 satisfy the relationship represented by the following Formula (2): 0.35??H2/?H1?0.95??Formula (1) Tf1/2?205?(1.4×Tm1)??Formula (2).
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: May 11, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Noriyuki Mizutani, Hideo Maehata, Hirokazu Hamano, Hiroyuki Tanaka, Moegi Iguchi, Soichiro Kitagawa, Susumu Yoshino, Yuka Ishihara, Yosuke Tsurumi, Akira Matsumoto, Masaru Takahashi
  • Patent number: 7303846
    Abstract: An electrophotographic toner contains at least a binder resin and a colorant, and log10{[Cu]/[C]} satisfies the following equation (1): ?5.0?log10{[Cu]/[C]}??3.5 ??(1) in which, [C] represents a carbon content (%) and [Cu] represents a copper content (%), measured with fluorescent X-ray. An electrophotographic developer containing the toner, a method for producing the toner, and a method for forming an image by using the toner are also provided.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: December 4, 2007
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Teruo Sakai, legal representative, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Sueko Sakai, deceased
  • Patent number: 7291436
    Abstract: An electrophotographic toner having a core-shell structure including a crystalline resin in its core region or a sea-island structure including a crystalline resin in its island region, wherein the toner has 1) a resistance of 5.0×1012 ?·cm or higher, 2) a dynamic viscosity coefficient of 3×103 Pa·s or higher at a temperature which is 50° C. higher than a melting point of the crystalline resin, and 3) a dynamic viscosity coefficient of 1×105 Pa·s or lower at a temperature which is 10° C. higher than the melting point of the crystalline resin.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: November 6, 2007
    Assignee: Fuji Xerox., Ltd.
    Inventors: Masaki Nakamura, Takashi Imai, Katsumi Daimon, Yuka Ishihara, Hirokazu Yamada, Hirokazu Hamano, Norihito Fukushima, Yasuhiro Arima
  • Publication number: 20060292473
    Abstract: An electrostatic latent image developing toner that is made by adding electrically conductive powder as an external additive to toner particles comprising a binder resin and a colorant, wherein the liberation rate of the electrically conductive powder is from 50 to 90%; and the number average particle size distribution index G of the toner particles, which is represented by the following formula (1), is 1.20 or less. particle size distribution index G=D50/D16??Formula (1) And an electrostatic latent image developing toner that is made by adding a metal oxide as an external additive to toner particles comprising a binder resin and a colorant, wherein the liberation rate of the metal oxide is from 30 to 60%.
    Type: Application
    Filed: December 14, 2005
    Publication date: December 28, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yasuo Kadokura, Yuka Ishihara, Yasuhiro Arima, Atsushi Sugawara, Shinya Nakashima, Masaki Nakamura, Yasuhiro Oya
  • Publication number: 20060204880
    Abstract: A toner for developing electrostatic images, comprising a binder resin and a colorant, the binder resin including a crystalline polyester resin and an amorphous resin. When, in differential scanning calorimetry of the toner according to ASTM D3418-8, the temperature of the endothermic peak derived from the crystalline polyester resin in a first heating process is defined as Tm1 (° C.), the endothermic quantity based on the endothermic peak in the first heating process is defined as ?H1 (mW/g), and the endothermic quantity based on the endothermic peak in a second heating process is defined as ?H2 (mW/g), Tm1 is 50 to 80° C, and ?H1 and ?H2 satisfy the relationship represented by the following Formula (1). When the softening temperature of the toner is defined as Tf1/2 (° C.), Tf1/2 is 85 to 135° C. Tm1 and Tf1/2 satisfy the relationship represented by the following Formula (2): 0.35??H2/?H1?0.95??Formula (1) Tf1/2?205?(1.4×Tm1)??Formula (2).
    Type: Application
    Filed: July 25, 2005
    Publication date: September 14, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Noriyuki Mizutani, Hideo Maehata, Hirokazu Hamano, Hiroyuki Tanaka, Moegi Iguchi, Soichiro Kitagawa, Susumu Yoshino, Yuka Ishihara, Yosuke Tsurumi, Akira Matsumoto, Masaru Takahashi
  • Publication number: 20060046173
    Abstract: An electrophotographic toner contains at least a binder resin and a colorant, and log10{[Cu]/[C]} satisfies the following equation (1): ?5.0?log10{[Cu]/[C]}??3.5 ??(1) in which, [C] represents a carbon content (%) and [Cu] represents a copper content (%), measured with fluorescent X-ray. An electrophotographic developer containing the toner, a method for producing the toner, and a method for forming an image by using the toner are also provided.
    Type: Application
    Filed: March 15, 2005
    Publication date: March 2, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Sueko Sakai, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Teruo Sakai
  • Publication number: 20050208414
    Abstract: An electrophotographic toner having a core-shell structure including a crystalline resin in its core region or a sea-island structure including a crystalline resin in its island region, wherein the toner has 1) a resistance of 5.0×1012 ?·cm or higher, 2) a dynamic viscosity coefficient of 3×103 Pa·s or higher at a temperature which is 50° C. higher than a melting point of the crystalline resin, and 3) a dynamic viscosity coefficient of 1×105 Pa·s or lower at a temperature which is 10° C. higher than the melting point of the crystalline resin.
    Type: Application
    Filed: October 14, 2004
    Publication date: September 22, 2005
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masaki Nakamura, Takashi Imai, Katsumi Daimon, Yuka Ishihara, Hirokazu Yamada, Hirokazu Hamano, Norihito Fukushima, Yasuhiro Arima
  • Patent number: 6942951
    Abstract: The present invention provides an image forming method for efficiently thermoelectrically transferring and fixing a toner image formed on an electrostatic latent image carrier without scattering of the toner. The image forming method comprises the steps of charging a surface of an electrostatic latent image carrier; exposing the charged surface of the electrostatic latent image carrier to a light beam using optical data corresponding to image data to form a latent image; developing the latent image formed on the surface of the electrostatic latent image carrier with a developer for electrophotography containing a toner for electrophotography to form a toner image; and thermoelectrically transferring the toner image formed on the surface of said electrostatic latent image carrier onto a surface of a recording medium and simultaneously fixing thereon. The toner for electrophotography is comprised of a crystalline polyester resin, the surface temperature of a fixing unit therein is higher by 10° C.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: September 13, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Daimon, Takashi Imai, Manabu Serizawa, Hirokazu Hamano, Norihito Fukushima, Yuka Ishihara
  • Patent number: 6895205
    Abstract: An image fixing apparatus and an image forming method capable of favorably fixing a toner containing a crystalline resin are provided. The image forming apparatus passes a transfer medium having unfixed images formed of the toner containing a crystalline resin between a heating member and a pressurizing member, thereby fixing the unfixed images, using a cooling unit that controls a surface temperature of the pressurizing member in which the surface temperature is controlled to a melting point of the crystalline resin +30° C. or lower.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: May 17, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masaki Nakamura, Toshimizu Ozawa, Yoshinari Ueno, Norihito Fukushima, Hirokazu Hamano, Yuka Ishihara