Patents by Inventor Masahide Yamada

Masahide Yamada 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: 20160017222
    Abstract: Disclosed is a phosphor including at least one of a nitride and an oxynitride, wherein the nitride and the oxynitride contain an alkaline-earth metal element, silicon, and an activator element. wherein the phosphor has a volume average particle diameter of greater than or equal to about 50 nm and less than or equal to about 400 nm and an inner quantum efficiency of greater than or equal to about 60% at an excitation wavelength of about 450 nm. The method of preparing a phosphor includes a precursor preparation process of preparing a phosphor precursor particles including a silicon nitride particles, a compound containing an alkaline-earth metal element, and a compound containing an activator element, wherein the compound containing an alkaline-earth metal element and the compound containing an activator element are deposited on the surface of the silicon nitride particles; and a firing process of firing the phosphor precursor particles.
    Type: Application
    Filed: July 20, 2015
    Publication date: January 21, 2016
    Inventors: Takuya KITABATAKE, Fusaki FUJIBAYASHI, Hiroko ENDO, Masahide YAMADA, Takatoshi SETO
  • Patent number: 9176406
    Abstract: Toner contains a binder resin containing a crystalline resin having a urethane and/or urea bonding; and a colorant, wherein in a diffraction spectrum of the toner as measured by an X-ray diffraction instrument, a ratio {C/(C+A)} of an integral intensity C of the spectrum derived from the crystalline structure to an integral intensity A of the spectrum derived from the non-crystalline structure is 0.12 or greater, wherein the toner satisfies the following relation 1: T1?T2?30° C. (Relation 1), where T1 represents the maximum endothermic peak in the first temperature rising from 0° C. to 100° C. at the temperature rising rate of 10° C./min and T2 represents the maximum exothermic peak in the first temperature falling from 100° C. to 0° C. at the temperature falling rate of 10° C./min as T1 and T2 are measured by diffraction scanning calorimetry (DSC).
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: November 3, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoyuki Sekiguchi, Hiroshi Yamashita, Minoru Masuda, Susumu Chiba, Tatsuya Morita, Atsushi Yamamoto, Shinya Nakayama, Masahide Yamada, Kohsuke Nagata, Keiji Makabe, Toyoshi Sawada
  • Patent number: 9141013
    Abstract: An electrophotographic toner including: a binder resin, wherein the binder resin has one glass transition temperature Tg and the glass transition temperature Tg of the binder resin is within 25° C. to 65° C. as measured in second heating with a differential scanning calorimeter at a heating rate of 5° C./min, and wherein a phase image of the binder resin obtained with an atomic force microscope (AFM) of tapping mode contains first phase difference regions and a second phase difference region such that the first phase difference regions are dispersed in the second phase difference region, where the first phase difference regions correspond to greater phase difference regions and the second phase difference region corresponds to a smaller phase difference region when an intermediate value between a maximum value and a minimum value of the phase differences is used as a threshold.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: September 22, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Moriya, Masahide Yamada, Taichi Nemoto, Yukiko Nakajima, Yoshitaka Yamauchi, Keiji Makabe, Daiki Yamashita, Suzuka Amemori, Akiyoshi Sabu
  • 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
  • Patent number: 9128397
    Abstract: A resin for use in toner is provided. The resin comprises an oligomer segment and a soft segment. The oligomer segment comprises a polyhydroxycarboxylic skeleton and an aromatic diol skeleton.
    Type: Grant
    Filed: May 15, 2012
    Date of Patent: September 8, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yukiko Nakajima, Masahide Yamada, Taichi Nemoto, Yoshihiro Moriya, Yoshitaka Yamauchi, Keiji Makabe, Daiki Yamashita, Akiyoshi Sabu
  • Patent number: 9127118
    Abstract: A resin for toner contains a polyhydroxycarboxylic acid skeleton and a rigid skeleton.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: September 8, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hideyuki Santo, Shinya Nakayama, Atsushi Yamamoto, Yoshihiro Moriya, Akiyoshi Sabu, Daisuke Asahina, Yoshitaka Yamauchi, Taichi Nemoto, Yukiko Nakajima, Daiki Yamashita, Masahide Yamada, Keiji Makabe
  • Publication number: 20150234304
    Abstract: A toner including a crystalline resin wherein the crystalline resin contains a crystalline resin having a urethane bond, a urea bond or both thereof, and wherein the crystalline resin has an average crystallite diameter of 20 nm to 70 nm.
    Type: Application
    Filed: September 10, 2013
    Publication date: August 20, 2015
    Inventors: Kousuke Nagata, Masahide Yamada, Shinya Nakayama, Akiyoshi Sabu, Tatsuya Morita, Takamasa Hase, Suzuka Amemori, Rintaro Takahashi
  • 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: 9012116
    Abstract: A toner including a binder resin having a glass transition temperature (Tg) observed at least at one point from 25 to 65° C. in a differential scanning calorimeter at a rate of temperature increase of 5° C./min, wherein the toner has a structure in which a structure appearing as a high phase difference image is dispersed in a structure appearing as a low phase difference image in a two-dimensional phase difference image observed by tapping mode AFM, and an X-ray diffraction chart in which a peak originated from an crystalline resin is observed in a range of a diffraction angle 2? of from 20 to 25°, and wherein a ratio (I1/I2) of an intensity of the peak originated from an crystalline resin to an intensity (I2) of a halo originated from an amorphous composition is from 0.2 to 1.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: April 21, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Daiki Yamashita, Yoshihiro Moriya, Yukiko Nakajima, Taichi Nemoto, Yoshitaka Yamauchi, Keiji Makabe, Masahide Yamada, Suzuka Amemori
  • Patent number: 8951707
    Abstract: A toner, including: a crystalline resin containing a urethane bond, a urea bond, or both thereof; and a compound represented by the following General Formula (1), wherein an amount of the compound represented by the General Formula (1) is 0.01% by mass to 0.25% by mass: CnH2n+1R??General Formula (1) where n is 8 to 22 and R is COOH, NH2 or OH.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: February 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Suzuka Amemori, Atsushi Yamamoto, Masahide Yamada, Yukiko Nakajima, Shinya Nakayama, Hideyuki Santo
  • Patent number: 8951705
    Abstract: A development agent containing toner that contains a binder resin having a crystalline resin that has a urethane and/or urea bond in its main chain, a coloring agent, and an organically modified inorganic laminate compound in which organic ions are at least partially substituted for ions present between layers of the organically modified inorganic laminate compound, and toner carrier that contains a core material whose surface is coated with a coating layer having a condensed compound of a melamine resin and/or a guanamine resin and an acrylic resin having a hydroxyl group.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: February 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Yukiko Nakajima, Masahide Yamada, Hideyuki Santo, Suzuka Amemori
  • Patent number: 8932790
    Abstract: The toner includes a pigment; and a block copolymer having a polyester block A including a residual group of a hydroxycarboxylic acid, and a polyester block B including an anionic group. When cross-section of the block copolymer is observed by a tapping mode atomic force microscope to obtain a phase image of the cross-section, the polyester block B, which has relatively large phase delay, is dispersed as domains having an average size of from 20 nm to 100 nm in a domain of the polyester block A, which has relatively small phase delay. The block copolymer has a first glass transition temperature of from ?20° C. to 20° C., and a second glass transition temperature of from 35° C. to 65° C. when the first and second glass transition temperatures are determined from a thermogram obtained by subjecting the block copolymer to differential scanning calorimetry (DSC) at a temperature rising speed of 5° C./min.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: January 13, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshitaka Yamauchi, Masahide Yamada, Yoshihiro Moriya, Taichi Nemoto, Yukiko Nakajima, Keiji Makabe, Daiki Yamashita, Suzuka Amemori, Akiyoshi Sabu
  • Publication number: 20140342284
    Abstract: An electrophotographic toner including: a binder resin, wherein the binder resin has one glass transition temperature Tg and the glass transition temperature Tg of the binder resin is within 25° C. to 65° C. as measured in second heating with a differential scanning calorimeter at a heating rate of 5° C./min, and wherein a phase image of the binder resin obtained with an atomic force microscope (AFM) of tapping mode contains first phase difference regions and a second phase difference region such that the first phase difference regions are dispersed in the second phase difference region, where the first phase difference regions correspond to greater phase difference regions and the second phase difference region corresponds to a smaller phase difference region when an intermediate value between a maximum value and a minimum value of the phase differences is used as a threshold.
    Type: Application
    Filed: September 12, 2012
    Publication date: November 20, 2014
    Inventors: Yoshihiro Moriya, Masahide Yamada, Taichi Nemoto, Yukiko Nakajima, Yoshitaka Yamauchi, Keiji Makabe, Daiki Yamashita, Suzuka Amemori, Akiyoshi Sabu
  • 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: 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
  • Publication number: 20140272698
    Abstract: Toner contains a binder resin containing two or more kinds of crystalline resins; and a coloring agent, wherein the two or more kinds of crystalline resins have at least two endothermic peak temperatures in a set of endothermic peak temperatures of the two or more kinds of crystalline resins as measured by differential scanning calorimetry (DSC).
    Type: Application
    Filed: March 14, 2014
    Publication date: September 18, 2014
    Inventors: Masahide YAMADA, Atsushi Yamamoto, Satoyuki Sekiguchi, Keiji Makabe, Kohsuke Nagata, Toyoshi Sawada
  • 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
  • Patent number: 8808955
    Abstract: A toner includes a coloring agent, a binder resin comprising a crystalline resin having a urethane skeleton and/or urea skeleton, and a releasing agent (a microcrystalline wax). A development agent, a process cartridge, and an image forming apparatus employ the toner to form images on recording media electrophotographically.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: August 19, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Daiki Yamashita, Suzuka Amemori, Masahide Yamada