Patents by Inventor Daisuke Yoshiba

Daisuke Yoshiba 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: 9097998
    Abstract: A toner is provided which is superior in the long-term storage stability and has high low-temperature fixing properties. In a DSC curve as measured with a differential scanning calorimeter, the toner has a glass transition temperature of not less than 50° C. and not more than 60° C.; and the toner has, in regard to a resin composition contained therein, a difference of not less than 0.060 W/g in heat flow between a point on the curve at a temperature of 40° C. and a baseline in the range exceeding the glass transition temperature; and in viscoelastic characteristics measured at a frequency of 6.28 rad/sec, the toner has a storage elastic modulus (G?40) at a temperature of 40° C. of not less than 7.0×108 Pa and not more than 2.0×109 Pa, and a storage elastic modulus (G?70) at a temperature of 70° C. of not less than 1.0×105 Pa and not more than 1.0×107 Pa.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: August 4, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20150037722
    Abstract: The present invention provides a toner that exhibits an excellent low-temperature fixability and an excellent ejected paper adhesiveness during high-speed printing, without affecting the long-term storage stability, in which the toner has a toner particle that contains a resin component, wherein the toner has, in a DSC curve measured with a differential scanning calorimeter, a glass transition temperature of at least 50° C. and not more than 65° C. and a cold crystallization peak during cooling of at least 40° C. and not more than 70° C., and has an endothermic peak in a DSC curve measured with a differential scanning calorimeter for the resin component of at least 70° C. and not more than 95° C.
    Type: Application
    Filed: July 28, 2014
    Publication date: February 5, 2015
    Inventors: Katsuhisa Yamazaki, Daisuke Yoshiba, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20150037729
    Abstract: The toner includes a resin component containing a crystalline polyester resin and a polyester-type resin that has a long-chain monomer bonded by condensation at a terminal, the toner having, in a total heat flow measured by a temperature-modulated differential scanning calorimeter, an endothermic peak resulting from the crystalline polyester resin in a specific temperature range, and the percentage of the endothermic quantity of the endothermic peak in a reversing heat flow with respect to the endothermic quantity of the endothermic peak in the total heat flow being at least 20.0%.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20150037726
    Abstract: The toner comprises: toner particles each containing a binder resin and a releasing agent; and an organic-inorganic composite fine particle, wherein: the organic-inorganic composite fine particle comprises: a vinyl resin particle containing a vinyl resin, the vinyl resin containing THF-insoluble matter in an amount of 95% by mass or more; and inorganic fine particles which are exposed at surfaces of the respective organic-inorganic composite fine particles, the organic-inorganic composite fine particle 1) has a plurality of convexes derived from the inorganic fine particles on the surfaces thereof, 2) has a number average particle size of 70-500 nm, and 3) has a shape factor SF-2 as measured at a magnification of 200,000 times of 103-120, and an absolute value of difference between an SP value of the releasing agent and an SP value of the vinyl resin is 0.50 (cal/cm3)1/2 or less.
    Type: Application
    Filed: July 24, 2014
    Publication date: February 5, 2015
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Publication number: 20150037721
    Abstract: Provided is a toner that has excellent low-temperature fixability and is capable of obtaining an image having a stable image density, in which the occurrence of image defects is suppressed. The toner includes toner base particles, each of which contains a binder resin and a magnetic material, and organic-inorganic composite fine particles on each of the toner base particles. Each of the organic-inorganic composite fine particles comprises a vinyl resin particle, and inorganic fine particles which are embedded in the vinyl resin particle, and at least a part of which are exposed. The volumetric specific heat of the organic-inorganic composite fine particles and the volumetric specific heat of the toner base particles satisfy a predetermined provision.
    Type: Application
    Filed: July 30, 2014
    Publication date: February 5, 2015
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Publication number: 20150037723
    Abstract: A toner excellent in end-portion hot offset properties is provided. A toner including toner particles and an external additive, wherein the toner particles contain a binder resin, and organic-inorganic composite fine particles dispersed in the binder resin, and the organic-inorganic composite fine particles (1) have a number-average particle diameter of 70 nm or more and 500 nm or less, (2) have a structure in which inorganic fine particles are embedded in a resin particle, convexes derived from the inorganic fine particles being present on surfaces of the organic-inorganic composite fine particles, (3) have a shape factor SF-2 of 103 or more and 120 or less, and (4) contain a resin component in which a proportion of THF-insoluble matter based on a mass of the resin component is 95% by mass or more.
    Type: Application
    Filed: July 25, 2014
    Publication date: February 5, 2015
    Inventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Patent number: 8740516
    Abstract: A threading cutting insert achieves high shape accuracy of a screw to be processed, and saves on manufacturing cost. Therefore in the threading cutting insert, a plurality of tooth-shaped cutting edges are formed in a cross ridge line portion between a rake face and flanks formed in a cutting side face, wherein the plurality of mountain-shaped cutting edges provides at least one finishing cutting edge for transferring a shape of a screw, and at least one roughing cutting edge formed in a tooth shape smaller than that of the finishing cutting edge. A flank of the finishing cutting edge includes a first flank, and a second flank having a clearance angle larger than that of the first flank, wherein the finishing cutting edge, the first flank, and the second flank are sequentially provided in that order from the rake surface in a direction of a lower surface of the insert.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: June 3, 2014
    Assignee: Tungaloy Corporation
    Inventors: Daisuke Yoshiba, Eiichi Nunokawa
  • Publication number: 20140004460
    Abstract: A toner is provided in which low-temperature fixing properties and high-temperature offset resistance can be compatible, and the environmental stability of image density can also be obtained. A toner obtained by condensation polymerization of an alcohol component containing not less than 70 mol % of an aliphatic polyalcohol with a carboxylic acid component, and including a polyester resin having a concentration of an ester group of not less than 25% by mass and not more than 55% by mass, and a compound represented by the following formula (1) as a charge-controlling agent: (wherein A1, A2, and A3 each independently represent H, a nitro group, or a halogen atom; B1 represents H or an alkyl group; M represents an Fe atom, a Cr atom, or an Al atom; X+ represents a H ion, an alkali metal ion, a NH4 ion, an alkylammonium ion, or mixed ions thereof.
    Type: Application
    Filed: March 21, 2012
    Publication date: January 2, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Daisuke Yoshiba, Yoshihiro Ogawa, Kouji Nishikawa, Shigeto Tamura, Naohiko Tsuchida, Masami Fujimoto
  • Publication number: 20130302730
    Abstract: To provide a toner that can keep its melt-sticking to sleeve from occurring and, even in double-sided printing, can keep high-temperature offset from occurring and obtain high-quality images on both the surface and the back. The toner comprises toner particles each of which contains a binder resin containing a resin formed by the reaction of i) a resin (A) having a softening point TA (° C.) of 70° C. to 105° C. and having a peak top of endothermic peaks at 55° C. to 120° C. with ii) a resin (B) having a softening point TB (° C.) of 120° C. to 160° C. and having a peak top of endothermic peaks at 55° C. to 120° C., and, in its viscoelasticity characteristics, has a storage elastic modulus at temperature 180° C. (G?180) of 3.0×103 Pa to 3.0×104 Pa, where the loss tangent tan ? has at least one peak having a peak top within the range of 50° C. to 70° C. and, when peak top temperature of the peak is represented by T(° C.), the loss tangent at T+10(° C.) [tan ?(T+10)] is 1.0 to 1.
    Type: Application
    Filed: December 15, 2011
    Publication date: November 14, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Toru Takahashi, Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20130252167
    Abstract: A toner comprising toner particles, each of which contains a binder resin and a colorant, wherein the binder resin includes a resin having an endothermic peak at a temperature of 55° C. to 120° C. in a DSC curve; the toner has a softening point Tm of 90° C. to 140° C.; in the viscoelastic characteristic of the toner measured at a frequency of 6.28 rad/sec, the storage elastic modulus at a temperature of 180° C. is 1.0×102 Pa to 1.0×104 Pa; in a chart with the temperature on the x-axis and tan ? on the y-axis, tan ? has a peak having a peak top in the range of 50° C. to 70° C.; tan ? (P) at the peak top temperature is 2.0 to 10.0; the ratio of the tan ? (P) at the peak top temperature to tan ? (Tm) at a temperature of Tm (tan ? (P)/tan ? (Tm)) is in the range of 2.5 to 8.0.
    Type: Application
    Filed: December 13, 2011
    Publication date: September 26, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shuhei Moribe, Katsuhisa Yamazaki, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Publication number: 20130244166
    Abstract: A toner is provided which is superior in the long-term storage stability and has high low-temperature fixing properties. In a DSC curve as measured with a differential scanning calorimeter, the toner has a glass transition temperature of not less than 50° C. and not more than 60° C.; and the toner has, in regard to a resin composition contained therein, a difference of not less than 0.060 W/g in heat flow between a point on the curve at a temperature of 40° C. and a baseline in the range exceeding the glass transition temperature; and in viscoelastic characteristics measured at a frequency of 6.28 rad/sec, the toner has a storage elastic modulus (G?40) at a temperature of 40° C. of not less than 7.0×108 Pa and not more than 2.0×109 Pa, and a storage elastic modulus (G?70) at a temperature of 70° C. of not less than 1.0×105 Pa and not more than 1.0×107 Pa.
    Type: Application
    Filed: December 22, 2011
    Publication date: September 19, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Katsuhisa Yamazaki, Shuhei Moribe, Daisuke Yoshiba, Toru Takahashi, Daisuke Tsujimoto, Masami Fujimoto
  • Patent number: 8507170
    Abstract: An image-forming method includes forming an electrostatic image on an electrostatic image bearing member which has been charged; developing the electrostatic image to form a toner image; transferring the toner image on the electrostatic image bearing member with or without mediating an intermediate transferring member onto a transfer material; and fixing the toner image on the transfer material. The electrostatic image bearing member is a photosensitive member obtained by sequentially laminating a photoconductive layer and a surface layer formed of hydrogenated amorphous silicon carbide, and a sum of an atomic density of silicon atoms and an atomic density of carbon atoms in the surface layer of the photosensitive member is 6.60×1022 atoms/cm3 or more. The toner has a binder resin and magnetic iron oxide particles, and the magnetic iron oxide particles contain Fe(2+) at a content of 20.0 mass % or more and 25.0 mass % or less.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: August 13, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tooru Takahashi, Katsuhisa Yamazaki, Syuhei Moribe, Daisuke Yoshiba, Masami Fujimoto
  • Patent number: 8057977
    Abstract: Provide is a toner including toner particles each containing at least a binder resin and a colorant, and an inorganic fine powder, in which the inorganic fine powder has a ratio (A/B) of a total pore volume A measured in a pore diameter range of from 1.9 nm or more and to 8.0 nm or less to a total pore volume B measured in a pore diameter range of from 1.9 nm or more and to 300.0 nm or less of from 0.20 or more and to 1.00 or less, and the total pore volume A is from 1.00×10?2 cm3/g or more and to 1.00 cm3/g or less.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: November 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Syuhei Moribe, Katsuhisa Yamazaki, Daisuke Yoshiba, Masami Fujimoto
  • Publication number: 20110097655
    Abstract: Provided is an image-forming method, the method including: forming an electrostatic image on an electrostatic image bearing member which has been charged; developing the electrostatic image to form a toner image; transferring the toner image on the electrostatic image bearing member with or without mediating an intermediate transferring member onto a transfer material; and fixing the toner image on the transfer material, in which: the electrostatic image hearing member is a photosensitive member obtained by sequentially laminating a photoconductive layer and a surface layer formed of hydrogenated amorphous silicon carbide, and a sum of an atomic density of silicon atoms and an atomic density of carbon atoms in the surface layer of the photosensitive member is 6.60×1022 atoms/cm3 or more; and the toner has a binder resin and magnetic iron oxide particles, and the magnetic iron oxide particles contain Fe(2+) at a content of 20.0 mass % or more and 25.0 mass % or lees.
    Type: Application
    Filed: July 24, 2009
    Publication date: April 28, 2011
    Applicant: Canon Kabushiki Kaisha
    Inventors: Tooru Takahashi, Katsuhisa Yamazaki, Syuhei Moribe, Daisuke Yoshiba, Masami Fujimoto
  • Patent number: 7855042
    Abstract: To provide a developer and an image forming method with each of which a high-resolution, high-definition image can be stably obtained over a long time period irrespective of an environment. The present invention provides a developer including at least: toner particles each containing at least a binder resin; and a composite inorganic fine powder, the developer being characterized in that: the composite inorganic fine powder has a peak at a Bragg angle (2?±0.20 deg) of each of 32.20 deg, 25.80 deg, and 27.50 deg in a CuK? characteristic X-ray diffraction pattern; and the half width of the X-ray diffraction peak at a Bragg angle (2?±0.20 deg) of 32.20 deg is 0.20 to 0.30 deg.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: December 21, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakuni Kobori, Kenji Okado, Masami Fujimoto, Katsuhisa Yamazaki, Syuhei Moribe, Daisuke Yoshiba
  • Patent number: 7842447
    Abstract: To provide a toner which allows low temperature fixation irrespective of the configuration of a fuser, which is excellent in offset resistance, and which provides high image quality at high and low humidities in a stable manner without causing any image defect over time. A toner containing: a binder resin and a colorant; in which the toner contains a THF-soluble component to be dissolved in tetrahydrofuran (THF); the binder resin component contained in the THF-soluble component contains: a vinyl resin unit (I) formed by at least a carboxyl group-containing vinyl resin and an epoxy group-containing vinyl resin and having an epoxy value of 0.001 to 1.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: November 30, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhisa Yamazaki, Masami Fujimoto, Daisuke Yoshiba
  • Patent number: 7796926
    Abstract: A developing apparatus is provided which can suppress a fluctuation in image density in a discontinuous printing mode provided with a pause period. The developing apparatus includes a developer for developing an electrostatic latent image on a photosensitive drum, a developer bearing member for carrying and conveying the developer and a developer layer thickness-regulating unit placed close to the developer bearing member for regulating the amount of the developer carried and conveyed by the developer bearing member, the developer layer thickness-regulating unit being. As the developer, a negatively chargeable, one-component, magnetic toner is used having magnetic toner particles containing a binder resin and a magnetic iron oxide particle, and has a specific saturation magnetization, specific weight-average particle diameter and specific composition.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: September 14, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takuma Matsuda, Masayoshi Shimamura, Yasutaka Akashi, Satoshi Otake, Minoru Ito, Kazuhito Wakabayashi, Daisuke Yoshiba
  • Patent number: 7740998
    Abstract: A positively chargeable developer is provided which is capable of providing stable image quality without causing any image defect even in long-term use. The developer includes at least positively chargeable toner particles each containing at least a binder resin and magnetic iron oxide, silica and an inorganic fine powder. A unconfined yield strength at a major consolidation stress of 5 kPa of the developer is in the range of 0.1 to 2.5 kPa, and a unconfined yield strength at a major consolidation stress of 20 kPa of the developer is in the range of 2.5 to 5.5 kPa.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: June 22, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhisa Yamazaki, Daisuke Yoshiba, Masami Fujimoto
  • Patent number: 7700254
    Abstract: The present invention aims to provide a toner having excellent developability and excellent low-temperature fixability without causing adhesion of ejected sheets even in a high-speed oilless fixing system and capable of preventing a frameless printing from causing a twisted offseting phenomenon. Specifically, provided is a toner having toner particles including at least a binder resin and a colorant, in which, when the toner is dissolved in a tetrahydrofuran (THF) solvent at 25° C. for 24 hours, the ratio of a THF-soluble matter having an intrinsic viscosity of 5.0×10?2 dl/g or less with respect to the total amount of the THF-soluble matter in a GPC-RALLS-viscometer analysis is 15.0 mass % to 60.0 mass %, and the ratio of a THF-soluble matter having an intrinsic viscosity of 1.5×10?1 dl/g or more with respect to the total amount of the THF-soluble matter in a GPC-RALLS-viscometer analysis is 20.0 mass % to 40.0 mass %.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: April 20, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Syuhei Moribe, Katsuhisa Yamazaki, Daisuke Yoshiba, Hirata Junko, Masami Fujimoto, Takashige Kasuya
  • Publication number: 20090257788
    Abstract: A developing apparatus is provided which can suppress a fluctuation in image density in a discontinuous printing mode provided with a pause period. The developing apparatus includes a developer for developing an electrostatic latent image on a photosensitive drum, a developer bearing member for carrying and conveying the developer and a developer layer thickness-regulating unit placed close to the developer bearing member for regulating the amount of the developer carried and conveyed by the developer bearing member, the developer layer thickness-regulating unit being. As the developer, a negatively chargeable, one-component, magnetic toner is used having magnetic toner particles containing a binder resin and a magnetic iron oxide particle, and has a specific saturation magnetization, specific weight-average particle diameter and specific composition.
    Type: Application
    Filed: June 17, 2009
    Publication date: October 15, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takuma Matsuda, Masayoshi Shimamura, Yasutaka Akashi, Satoshi Otake, Minoru Ito, Kazuhito Wakabayashi, Daisuke Yoshiba