Patents by Inventor Shingo Sakashita

Shingo Sakashita 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: 10274853
    Abstract: A toner includes a binder resin; a release agent; and two or more inorganic fine particles as external additives. At least one of the inorganic fine particles is silica. When an ultrasonic oscillation is applied to a dispersion including the toner and a dispersant and a rate of the silica releasing from the toner is 20% based on total silica, an application energy of the ultrasonic oscillation is from 8 to 14 kJ, and from 70 to 130 kJ when the rate of the silica releasing from the toner is 50%.
    Type: Grant
    Filed: June 21, 2016
    Date of Patent: April 30, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Takayuki Itoh, Naohiro Watanabe, Takahiro Honda, Shingo Sakashita, Daisuke Inoue, Rintaro Takahashi, Ayumi Satoh
  • Patent number: 9989869
    Abstract: A toner comprising a binder resin and a release agent, wherein the toner has a difference of 30 or less between a maximum value and a minimum value among peak intensities in a range of Molecular weight M±300 where Molecular weight M is a molecular weight selected from a range of from 300 through 5,000 in a molecular weight distribution of tetrahydrofuran (THF)-soluble components in the toner as measured by gel permeation chromatography (GPC), and wherein the peak intensities are defined as relative values assuming a maximum peak value in molecular weights of 20,000 or less is 100, in a molecular weight distribution curve taking an intensity as a vertical axis and a molecular weight as a horizontal axis as measured by GPC.
    Type: Grant
    Filed: January 5, 2016
    Date of Patent: June 5, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Inoue, Naohiro Watanabe, Ryota Inoue, Masana Shiba, Junichi Awamura, Shingo Sakashita, Tomoki Murayama, Yoshitsugu Kimura, Rintaro Takahashi, Akio Takei
  • Publication number: 20180052403
    Abstract: A toner comprising a binder resin and a release agent, wherein the toner has a difference of 30 or less between a maximum value and a minimum value among peak intensities in a range of Molecular weight M±300 where Molecular weight M is a molecular weight selected from a range of from 300 through 5,000 in a molecular weight distribution of tetrahydrofuran (THF)-soluble components in the toner as measured by gel permeation chromatography (GPC), and wherein the peak intensities are defined as relative values assuming a maximum peak value in molecular weights of 20,000 or less is 100, in a molecular weight distribution curve taking an intensity as a vertical axis and a molecular weight as a horizontal axis as measured by GPC.
    Type: Application
    Filed: January 5, 2016
    Publication date: February 22, 2018
    Inventors: Daisuke INOUE, Naohiro WATANABE, Ryota INOUE, Masana SHIBA, Junichi AWAMURA, Shingo SAKASHITA, Tomoki MURAYAMA, Yoshitsugu KIMURA, Rintaro TAKAHASHI, Akio TAKEI
  • Patent number: 9720339
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Grant
    Filed: July 26, 2016
    Date of Patent: August 1, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Shinya Nakayama, Masahide Yamada, Atsushi Yamamoto, Hideyuki Santo, Yukiko Nakajima, Suzuka Amemori
  • Publication number: 20160378006
    Abstract: A toner includes a binder resin; a release agent; and two or more inorganic fine particles as external additives. At least one of the inorganic fine particles is silica. When an ultrasonic oscillation is applied to a dispersion including the toner and a dispersant and a rate of the silica releasing from the toner is 20% based on total silica, an application energy of the ultrasonic oscillation is from 8 to 14 kJ, and from 70 to 130 kJ when the rate of the silica releasing from the toner is 50%.
    Type: Application
    Filed: June 21, 2016
    Publication date: December 29, 2016
    Inventors: Takayuki ITOH, Naohiro Watanabe, Takahiro Honda, Shingo Sakashita, Daisuke Inoue, Rintaro Takahashi, Ayumi Satoh
  • Patent number: 9523931
    Abstract: To provide a toner, which contains silica particles containing first silica particles, and second silica particles, wherein the toner is a toner produced by depositing the silica particles on surfaces of base particles, the first silica particles have an average primary particle diameter of 75 nm to 250 nm, the second silica particles have an average primary particle diameter of 10 nm to 50 nm, a mass ratio of the first silica particles to the base particles is 0.010 to 0.040, a mass ratio of the second silica particles to the base particles is 0.005 to 0.030, a liberation ratio of the silica particles from the toner by a ultrasonic vibration method is 5% by mass to 20% by mass, and an amount of particles having primary particle diameters of 30 nm or smaller in the silica particles librated from the toner by the ultrasonic vibration method is 20% by number or less.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: December 20, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Kojima, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
  • Patent number: 9519235
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: December 13, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Shinya Nakayama, Masahide Yamada, Atsushi Yamamoto, Hideyuki Santo, Yukiko Nakajima, Suzuka Amemori
  • Publication number: 20160334726
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Application
    Filed: July 26, 2016
    Publication date: November 17, 2016
    Inventors: Shingo SAKASHITA, Shinya NAKAYAMA, Masahide YAMADA, Atsushi YAMAMOTO, Hideyuki SANTO, Yukiko NAKAJIMA, Suzuka AMEMORI
  • Publication number: 20160195828
    Abstract: Toner including binder resin; wherein the toner, as measured by differential scanning calorimetry (DSC), has glass transition temperature in range of 40° C. through 70° C. at first temperature rising and has no glass transition temperature in range of X° C. through X?20° C. at second temperature rising where X° C. denotes the glass transition temperature at the first temperature rising, the toner has difference of 30 or less between maximum value and minimum value among peak intensities in range of Molecular weight M±300 where Molecular weight M is molecular weight selected from range of 300 through 5,000 in molecular weight distribution of THF-soluble components in the toner as measured by GPC, and the peak intensities are defined as relative values assuming the maximum peak value in molecular weights of 20,000 or less is 100, in molecular weight distribution curve taking intensity as vertical axis and molecular weight as horizontal axis as measured by GPC.
    Type: Application
    Filed: January 4, 2016
    Publication date: July 7, 2016
    Inventors: Ayumi SATOH, Naohiro WATANABE, Masana SHIBA, Takahiro HONDA, Ryota INOUE, Daisuke INOUE, Shingo SAKASHITA, Rintaro TAKAHASHI
  • Patent number: 9348245
    Abstract: A toner, including: a crystalline resin; a non-crystalline resin; and a colorant, wherein the toner has a sea-island structure which includes a sea containing the crystalline resin and an island containing the non-crystalline resin and the colorant, wherein the island is 1.0 ?m or less in domain diameter, and wherein the toner is 1.7×104 Pa or less in storage elastic modulus at 160° C.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: May 24, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Tatsuya Morita, Kazumi Suzuki, Shingo Sakashita, Masana Shiba, Taichi Nemoto, Yoshitaka Yamauchi, Azumi Miyaake, Rintaro Takahashi
  • Patent number: 9291931
    Abstract: Provided is an electrostatic charge image developing toner, including: toner base particles including a polyester resin as a binder resin; and an external additive on the surface of the toner base particles. The external additive includes silica. The silica is produced by sol-gel method, and is aspherical. The percentage of change in the specific surface area of the toner when it is stored under high-temperature, high-humidity conditions is from 25% to 45%.
    Type: Grant
    Filed: February 18, 2014
    Date of Patent: March 22, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Awamura, Tsuneyasu Nagatomo, Satoshi Kojima, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
  • Patent number: 9201365
    Abstract: An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100° C. of 500 Pa·s to 8,000 Pa·s and the release agent has melt viscosity at 100° C. of 20 mPa·s to 30 mPa·s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions: 45??c1?60, and 10??c1??c2, where ?c1 denotes receding contact angle [°] of the release agent to the release layer and ?c2 denotes receding contact angle [°] of the release agent to the toner.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: December 1, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Satoshi Kojima, Daisuke Misawa, Hiroshi Endoh, Tomoki Murayama, Rintaro Takahashi, Chihiro Kikuchi
  • Patent number: 9152084
    Abstract: A toner housing container includes: a container body housing a toner; a conveying portion; a pipe receiving port; and an uplifting portion. Flow rate index of the toner measured by powder rheometer and represented by “flow rate index=(total energy at a rotation speed of 10 mm/s)/(total energy at a rotation speed of 100 mm/s)” is in a range of “1.8?flow rate index?6.5”. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end of container body. Uplifting portion includes: uplifting wall surface extending from container body internal wall surface toward protruding portion; and curving portion curving to conform to protruding portion. When the toner housing container is mounted on the toner conveying device, the protruding portion is present between the curving portion and the toner receiving port of the conveying pipe being inserted.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: October 6, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Masana Shiba, Shingo Sakashita, Junichi Awamura, Tomoki Murayama, Chihiro Kikuchi, Masaya Fukuda, Hiroshi Hosokawa, Shunji Katoh, Shinji Tamaki, Hiroshi Ikeguchi, Kenji Kikuchi, Michiharu Suzuki
  • Publication number: 20150261144
    Abstract: An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100° C. of 500 Pa·s to 8,000 Pa·s and the release agent has melt viscosity at 100° C. of 20 mPa·s to 30 mPa·s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions: 45??c1?10, and 10??c1??c2, where ?c1 denotes receding contact angle [°] of the release agent to the release layer and ?c2 denotes receding contact angle [°] of the release agent to the toner.
    Type: Application
    Filed: March 13, 2015
    Publication date: September 17, 2015
    Inventors: Shingo SAKASHITA, Satoshi KOJIMA, Daisuke MISAWA, Hiroshi ENDOH, Tomoki MURAYAMA, Rintaro TAKAHASHI, Chihiro KIKUCHI
  • Patent number: 9134638
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: September 15, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Shinya Nakayama, Masahide Yamada, Atsushi Yamamoto, Hideyuki Santo, Yukiko Nakajima, Suzuka Amemori
  • Publication number: 20150227071
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Application
    Filed: April 23, 2015
    Publication date: August 13, 2015
    Inventors: Shingo SAKASHITA, Shinya NAKAYAMA, Masahide YAMADA, Atsushi YAMAMOTO, Hideyuki SANTO, Yukiko NAKAJIMA, Suzuka AMEMORI
  • Patent number: 9086647
    Abstract: A developing device, including: a developer bearing member, which is disposed opposite to an electrostatic latent image bearing member and which bears thereon a developer for developing an electrostatic latent image formed on the electrostatic latent image bearing member and conveys the developer to a developing region, wherein the developer includes a toner and a carrier, the toner containing: a toner base containing a binder resin and a colorant; and an external additive, wherein the external additive contains coalescent particles each made up of a plurality of coalescing primary particles, and wherein a work function Wc of the carrier and a work function Ws of the developer bearing member satisfy a relationship of the following formula (1): Ws?Wc?0.4 eV??(1).
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: July 21, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Junichi Awamura, Tsuneyasu Nagatomo, Satoshi Kojima, Tomoki Murayama
  • Patent number: 9069288
    Abstract: Toner housing container includes: container body mountable on toner conveying device and housing toner supplied into toner conveying device; conveying portion provided in container body and conveying toner from longer direction one end of container body to other end at which container opening portion is provided; pipe receiving port provided at container opening portion and receiving conveying pipe fixed to toner conveying device; and uplifting portion to move toner conveyed by conveying portion toward toner receiving port of conveying pipe. Toner has loose apparent density of 0.28 g/cm3 to 0.53 g/cm3. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end. Uplifting portion includes uplifting wall surface extending from internal wall surface of container body toward protruding portion, and curving portion curving to conform to protruding portion.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: June 30, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Satoshi Kojima, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda, Hiroshi Hosokawa, Shunji Katoh, Shinji Tamaki, Hiroshi Ikeguchi, Kenji Kikuchi, Michiharu Suzuki
  • Publication number: 20150037718
    Abstract: A toner, including: a crystalline resin; a non-crystalline resin; and a colorant, wherein the toner has a sea-island structure which includes a sea containing the crystalline resin and an island containing the non-crystalline resin and the colorant, wherein the island is 1.0 ?m or less in domain diameter, and wherein the toner is 1.7×104 Pa or less in storage elastic modulus at 160° C.
    Type: Application
    Filed: March 7, 2013
    Publication date: February 5, 2015
    Inventors: Tatsuya Morita, Kazumi Suzuki, Shingo Sakashita, Masana Shiba, Taichi Nemoto, Yoshitaka Yamauchi, Azumi Miyaake, Rintaro Takahashi
  • Publication number: 20140348546
    Abstract: Toner housing container includes: container body mountable on toner conveying device and housing toner supplied into toner conveying device; conveying portion provided in container body and conveying toner from longer direction one end of container body to other end at which container opening portion is provided; pipe receiving port provided at container opening portion and receiving conveying pipe fixed to toner conveying device; and uplifting portion to move toner conveyed by conveying portion toward toner receiving port of conveying pipe. Toner has loose apparent density of 0.28 g/cm3 to 0.53 g/cm3. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end. Uplifting portion includes uplifting wall surface extending from internal wall surface of container body toward protruding portion, and curving portion curving to conform to protruding portion.
    Type: Application
    Filed: May 20, 2014
    Publication date: November 27, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Satoshi Kojima, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda, Hiroshi Hosokawa, Shunji Katoh, Shinji Tamaki, Hiroshi Ikeguchi, Kenji Kikuchi, Michiharu Suzuki