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).

  • Publication number: 20140348545
    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: Application
    Filed: May 20, 2014
    Publication date: November 27, 2014
    Applicant: 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
  • Patent number: 8895217
    Abstract: An electrostatic image forming toner including: toner base particles each containing at least a colorant, a binder resin, and a releasing agent, wherein the binder resin contains a non-crystalline polyester resin A and a crystalline polyester resin B, wherein a ratio of B/(A+B)×100 is 10 or more but less than 50 where (A+B) is a total mass of the non-crystalline polyester resin A and the crystalline polyester resin B and “B” is a mass of the crystalline polyester resin B, and wherein the toner base particles have a TMA compression deformation amount (TMA %) of 10% or less which is measured at 50° C. and a relative humidity of 90%.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: November 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Asahina, Tsuyoshi Sugimoto, Rintaro Takahashi, Hiroshi Yamashita, Taichi Nemoto, Shingo Sakashita, Yoshitaka Yamauchi, Satoyuki Sekiguchi
  • Patent number: 8883385
    Abstract: A toner includes a binder resin, a coloring agent, and a releasing agent containing two or more kinds of alkyl monoester compounds having a different number of carbon atoms in a range of from 30 to 50 carbon atoms. The toner has a crystallinity of 10% or more as measured by x-ray diffraction and/or the binder resin is a crystalline resin in an amount of 50% by weight or more of the binder resin. The two or more kinds of alkyl monoester compounds include a component A accounting for the largest amount ranging from 30% by weight to less than 50% by weight of the releasing agent and a component B accounting for the second largest amount ranging from 10% by weight to less than 50% by weight of the releasing agent.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: November 11, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Hiroshi Yamashita, Masahide Yamada, Shinya Nakayama, Atsushi Yamamoto, Yukiko Nakajima
  • Patent number: 8865383
    Abstract: A toner comprising an amorphous polyester, a crystalline polyester that is forming domains in the toner, and a colorant that is being dispersed at least in the domains of the crystalline polyester. The toner may be obtained by dispersing an oil phase including the amorphous polyester or a precursor capable of producing the amorphous polyester, the crystalline polyester, the colorant, and an organic solvent, in an aqueous medium to prepare an O/W dispersion, the oil phase; and removing the organic solvent from the O/W dispersion.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: October 21, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Tatsuya Morita, Shingo Sakashita, Tsuyoshi Sugimoto
  • Patent number: 8865384
    Abstract: An electrophotographic toner, including: a binder resin; a colorant; and an organically-modified layered inorganic mineral, wherein the binder resin contains 50% by mass or more of a crystalline resin relative to the binder resin, and the crystalline resin contains a resin having a sulfonic acid group, and wherein an amount of the sulfonic acid group is 0.1% by mass to 2.0% by mass relative to the resin having the sulfonic acid group.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: October 21, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamada, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Shingo Sakashita, Yukiko Nakajima, Suzuka Amemori, Akiyoshi Sabu
  • Patent number: 8859179
    Abstract: A developer, including a toner including a binder resin comprising a crystalline resin; and a colorant, and a resin carrier comprising a resin; a magnetic particulate material having a magnetic anisotropy, dispersed in the resin, and having a saturated magnetization of from 16 to 30 emu/g, a coercive force of from 15 to 40 kA/m and an average particle diameter not less than 15 ?m and less than 100 ?m.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: October 14, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyuki Santo, Masahide Yamada, Kazumi Suzuki, Shinya Nakayama, Atsushi Yamamoto, Tatsuya Morita, Shingo Sakashita, Yukiko Nakajima, Keiji Makabe, Daiki Yamashita
  • Publication number: 20140301757
    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: October 17, 2012
    Publication date: October 9, 2014
    Inventors: Shingo Sakashita, Shinya Nakayama, Masahide Yamada, Atsushi Yamamoto, Hideyuki Santo, Yukiko Nakajima, Suzuka Amemori
  • Patent number: 8822118
    Abstract: Toner containing a binder resin that contains at least one kind of resin having a crystalline polyester unit as its main component and a releasing agent containing a straight-chain mono ester having 48 or more carbon atoms accounting for 40% by weight or more of the releasing agent.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: September 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Shinya Nakayama, Hideyuki Santo, Suzuka Amemori, Shingo Sakashita, Masahide Yamada
  • Publication number: 20140234767
    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: Application
    Filed: February 18, 2014
    Publication date: August 21, 2014
    Inventors: Junichi AWAMURA, Tsuneyasu Nagatomo, Satoshi Kojima, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
  • Publication number: 20140220485
    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: Application
    Filed: January 30, 2014
    Publication date: August 7, 2014
    Inventors: Satoshi KOJIMA, Junichi Awamura, Tsuneyasu Nagatomo, Shingo Sakashita, Tomoki Murayama, Masaya Fukuda
  • Patent number: 8795940
    Abstract: To provide a toner, including at least: a non-crystalline polyester resin; and a crystalline polyester resin, wherein the toner has a glass transition temperature in a first heating Tg1st and a glass transition temperature in a second heating Tg2nd, and a difference between Tg1st and Tg2nd (Tg1st-Tg2nd) is 10° C. or greater, and wherein the crystalline polyester resin is a modified crystalline polyester resin having a urethane skeleton or a urea skeleton, or both thereof.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: August 5, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Daisuke Asahina, Rintaro Takahashi, Masahide Yamada, Shinya Nakayama, Atsushi Yamamoto, Shingo Sakashita
  • Patent number: 8778578
    Abstract: A toner set for electrophotography, including a black toner; a yellow toner; a magenta toner; a cyan toner; and a bright yellow toner, wherein the magenta toner includes a magenta colorant mainly including C.I. Pigment Red 122, the yellow toner has a hue angle of from 93 to 100° and the bright yellow toner has a hue angle of from 60 to 85° in L*a*b* color system.
    Type: Grant
    Filed: June 19, 2012
    Date of Patent: July 15, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Tatsuya Morita, Shingo Sakashita
  • Patent number: 8691486
    Abstract: An electrostatic image developing toner including a toner particle (C), wherein the toner particle (C) has a structure in which a resin particle (A) containing at least a first resin (a) or a coated film (P) containing the first resin (a) is attached to a surface of a resin-containing particle (B) containing a second resin (b), and wherein the resin (b) includes a polyhydroxycarboxylic acid skeleton, and the resin (a) is a polyester resin containing a polybasic acid and a polyhydric alcohol.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: April 8, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Akihiro Kotsugai, Akiyoshi Sabu, Shingo Sakashita, Yukiko Nakajima, Keiko Osaka
  • Patent number: 8679714
    Abstract: A toner including: a first binder resin; a colorant; a releasing agent; and a crystalline organic compound, wherein the first binder resin contains an amorphous polyester resin (a) having a polyhydroxycarboxylic acid skeleton derived from optically active monomers in a part of a main chain of the amorphous polyester resin, and the polyhydroxycarboxylic acid skeleton has an optical purity X, calculated on the monomer basis, of 80% or less, and the optical purity X is determined from the equation, Optical Purity X (%)=|X(L-form)?X(D-form)| wherein the crystalline organic compound is any one of a crystalline polyester resin (b) and a crystalline low molecular compound having a melting point of 60° C. to 100° C., and being selected from a group consisting of fatty acid having 16 to 24 carbon atoms, alcohol having 16 to 24 carbon atoms, a fatty acid ester compound, and aliphatic carboxylic acid amide.
    Type: Grant
    Filed: September 9, 2010
    Date of Patent: March 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Akihiro Kotsugai, Yoshihiro Moriya, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka, Yukiko Nakajima, Yoshitaka Yamauchi, Daiki Yamashita
  • Publication number: 20140072349
    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.
    Type: Application
    Filed: September 10, 2013
    Publication date: March 13, 2014
    Inventors: Shingo SAKASHITA, Junichi AWAMURA, Tsuneyasu NAGATOMO, Satoshi KOJIMA, Tomoki MURAYAMA
  • Patent number: 8663888
    Abstract: The present invention provides a toner including: a colorant, and a binder resin, wherein the toner is fixed on a recording medium using a fixing liquid containing a softening agent for softening the toner, and wherein a weight average molecular weight of a THF soluble fraction of the toner in a molecular weight distribution measured by gel permeation chromatography (GPC) is 3,000 to 8,300; and a glass transition temperature of the toner measured by differential scanning calorimetry (DSC) is 50° C. to 70° C.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: March 4, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasutada Shitara, Yohichiroh Watanabe, Yasuo Katano, Shinya Nakayama, Ryota Inoue, Yoshihiro Moriya, Akiyoshi Sabu, Shingo Sakashita, Yukiko Nakajima
  • Patent number: 8658340
    Abstract: A toner containing a binder resin comprising a first binder resin A and a second binder resin B, a coloring agent, and a releasing agent, wherein the first binder resin A is formed by reacting a compound A1 having an active hydrogen group with a resin A2 having a portion reactive with the compound A1 in an organic solvent and the resin A2 is formed by reacting a non-crystalline polyester resin “a” having a polyhydroxy carboxylic acid skeleton in the main chain with a compound having the portion reactive with the compound A1 having an active hydrogen group.
    Type: Grant
    Filed: May 9, 2011
    Date of Patent: February 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shingo Sakashita, Shinya Nakayama, Ryota Inoue, Yoshihiro Moriya, Akiyoshi Sabu, Yukiko Nakajima, Daiki Yamashita
  • Patent number: 8632932
    Abstract: A toner including a binder resin comprising a resin (a) comprising a polyhydroxycarboxylic acid skeleton formed from an optically-active monomer. The polyhydroxycarboxylic acid skeleton has a weight average molecular weight of from 7,000 to 60,000. The binder resin comprises the polyhydroxycarboxylic acid skeleton in an amount of from 10 to 90% by weight. The optical purity X (%) of the polyhydroxycarboxylic acid skeleton represented by the following formula is 80% or less: X(%)=|X(L-isomer)?X(D-isomer)| wherein X(L-isomer) and X(D-isomer) represent molar ratio (%) of L-isomer and D-isomer of the optically-active monomer, respectively.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: January 21, 2014
    Assignee: Ricoh Company, Limited
    Inventors: Akiyoshi Sabu, Akihiro Kotsugai, Ryota Inoue, Keiko Osaka, Shingo Sakashita, Yukiko Nakajima, Satoshi Mochizuki
  • Patent number: 8623580
    Abstract: To provide a toner including: a resin particle (C) containing a first resin (a1), a second resin (a2), and a resin particle (B) to a surface of which the first resin (a1) and the second resin (a2) are attached, wherein the first resin (a1) and the second resin (a2) have mutually different glass transition temperatures, and wherein the resin particle (B) contains a third resin (b) having an amorphous polyhydroxycarboxylic acid skeleton.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: January 7, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yukiko Nakajima, Akihiro Kotsugai, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka
  • Patent number: 8603718
    Abstract: An anisotropic magnetic material-dispersed resin carrier including: fine magnetic particles; and a binder resin in which at least the fine magnetic particles are dispersed, wherein the anisotropic magnetic material-dispersed resin carrier has a magnetic anisotropy where magnetic fields of the fine magnetic particles are orientated in the same direction, and wherein the anisotropic magnetic material-dispersed resin carrier has a saturation magnetization of 16 emu/g to 30 emu/g, a coercive force of 15 kA/m to 40 kA/m, and a number average particle diameter of 15 ?m or more but less than 100 ?m.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: December 10, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazumi Suzuki, Masaki Yoshino, Hisao Kurosu, Tatsuya Morita, Tomoko Kino, Shingo Sakashita