Patents by Inventor Yoshitaka Suzumura

Yoshitaka Suzumura 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: 20160327881
    Abstract: A magnetic toner contains magnetic toner particles containing a binder resin, a release agent, and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles, wherein a ratio of coverage of the magnetic toner particles' surface by the inorganic fine particles is in a prescribed range for the magnetic toner, the inorganic fine particles contain prescribed metal oxide fine particles, with at least 85 mass % of the metal oxide fine particles being silica fine particles, the coefficient of variation on the coverage ratio A is in a prescribed range, the binder resin contains a styrene resin, in a GPC measurement of a THF-soluble matter in the magnetic toner, a peak molecular weight (Mp) of a main peak is in a prescribed range, and a prescribed fatty acid ester compound is incorporated as a release agent.
    Type: Application
    Filed: July 22, 2016
    Publication date: November 10, 2016
    Inventors: Shuichi Hiroko, Michihisa Magome, Yusuke Hasegawa, Yoshitaka Suzumura
  • Publication number: 20160266509
    Abstract: The toner has a toner particle that contains a binder resin, a colorant, a release agent, and a crystalline polyester, wherein the release agent contains an ester wax, and the peak top temperature of the maximum endothermic peak of the ester wax as measured with a differential scanning calorimeter is from 65° C. to 85° C., the ester wax satisfies specific conditions and the crystalline polyester satisfies specific conditions, the toner contains from 3.0 parts by mass to 20.0 parts by mass of the crystalline polyester per 100 parts by mass of the binder resin, and the mass ratio of the ester wax to crystalline polyester is from 25/75 to 75/25.
    Type: Application
    Filed: February 24, 2016
    Publication date: September 15, 2016
    Inventors: Tomohisa Sano, Yusuke Hasegawa, Yoshitaka Suzumura, Yuujirou Nagashima, Kozue Uratani
  • Patent number: 9417542
    Abstract: A magnetic toner contains magnetic toner particles containing a binder resin, a release agent, and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles, wherein a ratio of coverage of the magnetic toner particles' surface by the inorganic fine particles is in a prescribed range for the magnetic toner, the inorganic fine particles contain prescribed metal oxide fine particles, with at least 85 mass % of the metal oxide fine particles being silica fine particles, the coefficient of variation on the coverage ratio A is in a prescribed range, the binder resin contains a styrene resin, in a GPC measurement of a THF-soluble matter in the magnetic toner, a peak molecular weight (Mp) of a main peak is in a prescribed range, and a prescribed fatty acid ester compound is incorporated as a release agent.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: August 16, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shuichi Hiroko, Michihisa Magome, Yusuke Hasegawa, Yoshitaka Suzumura
  • Patent number: 9372424
    Abstract: A magnetic toner contains magnetic toner particles and silica fine particles. The magnetic toner has a thermal conductivity in the range of 0.230 to 0.270 W/(m·K). Primary particles of the silica fine particles have a number-average particle diameter (D1) in the range of 5 to 20 nm. The coverage X1 of the magnetic toner surface by the silica fine particles ranges from 40% to 75% by area as determined using an X-ray photoelectron spectrometer (ESCA). The diffusion index (X1/X2) satisfies the following formula: Diffusion index??0.0042×X1+0.62 wherein X2 denotes the theoretical coverage of the magnetic toner surface by the silica fine particles.
    Type: Grant
    Filed: December 11, 2014
    Date of Patent: June 21, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Matsui, Yusuke Hasegawa, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
  • Patent number: 9335650
    Abstract: There are provided an image forming apparatus in which the generation of lateral streak images due to a decrease in the in-nip discharge intensity is suppressed while at the same time the generation of spot-like images due to abnormal discharge caused by smudges on the surface of a charging member is suppressed, and a process cartridge. The image forming apparatus and the process cartridge each has: a charging member containing a resin particle having a plurality of pores inside thereof; and a toner in which the coverage ratio X1 of a surface of the toner with silica fine particles is 50.0 area % or more and 75.0 area % or less, and when a theoretical coverage ratio with the silica fine particles is X2, a diffusion index represented by formula 1 satisfies formula 2. diffusion index=X1/X2??(formula 1) diffusion index??0.0042×X1+0.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: May 10, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takehiko Aoyama, Tomohito Taniguchi, Noboru Miyagawa, Taichi Sato, Atsushi Uematsu, Masahiro Watanabe, Yoshitaka Suzumura
  • Patent number: 9291936
    Abstract: There are provided an image-forming apparatus that inhibit the occurrence of a longitudinal streak image attributed to a cleaning failure, and a process cartridge. The image-forming apparatus and the process cartridge each have a charging member with a surface having a concavities derived from an opening of the bowl-shaped resin particle, and a protrusions derived from an edge of the opening of the bowl-shaped resin particle, the coverage ratio X1 of a surface of the toner with the silica fine particles is 50.0 area % or more and 75.0 area % or less, and when a theoretical coverage ratio of the toner by the silica fine particles is X2, a diffusion index represented by the formula 1 satisfies the formula 2: diffusion index=X1/X2??(formula 1) diffusion index??0.0042×X1+0.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: March 22, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomohito Taniguchi, Takehiko Aoyama, Taichi Sato, Noboru Miyagawa, Masahiro Watanabe, Atsushi Uematsu, Yoshitaka Suzumura
  • Patent number: 9244371
    Abstract: A magnetic toner contains magnetic toner particles containing a binder resin, a release agent, and a magnetic body and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles contain metal oxide fine particles, as described in the specification. The coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and the coverage ratio by the inorganic fine particles fixed to the magnetic toner particles' surface reside in a prescribed relationship, the binder resin contains a polyester resin, the release agent contains an ester compound, and an endothermic peak for the magnetic toner has a prescribed value.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: January 26, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yoshitaka Suzumura, Yusuke Hasegawa, Michihisa Magome, Kozue Uratani
  • Patent number: 9239528
    Abstract: A toner comprising toner particles which comprise a binder resin and a colorant, and also inorganic fine particles as external additives, wherein the inorganic fine particles are silica fine particles and a group 2 element titanate fine particles, the inorganic fine particles have specific particle diameters, the silica fine particles have a coverage ratio X1 on the surfaces of the toner particles, which is not less than 40.0 surface area % and not more than 75.0 surface area %, when the theoretical coverage ratio by the silica fine particles is X2, the diffusion index defined as “diffusion index=X1/X2” satisfies the condition: diffusion index??0.0042×X1+0.62, and the external additives have an embedding ratio on the toner particles, which satisfies a specific range.
    Type: Grant
    Filed: June 13, 2014
    Date of Patent: January 19, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
  • Patent number: 9213250
    Abstract: Disclosed is a toner which enables a stable image density to be obtained, regardless of the service environment, throughout use in durability tests, and which is able to suppress the occurrence of faulty cleaning. The toner contains both toner particles, which include a binder resin and a colorant, and also silica fine particles. The toner has an average circularity of at least 0.950, a static friction coefficient, with respect to a polycarbonate resin substrate, of at least 0.100 and not more than 0.200, and a coverage ratio X1 of the toner surface by the silica fine particles, as determined by X-ray photoelectron spectroscopy (ESCA), of at least 50.0 area %, and not more than 75.0 area %.
    Type: Grant
    Filed: September 30, 2013
    Date of Patent: December 15, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shotaro Nomura, Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori
  • Publication number: 20150227068
    Abstract: The magnetic toner contains a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein the average circularity of the magnetic toner is at least 0.955 and, when classifying the inorganic fine particles, in accordance with the fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X are in prescribed ranges.
    Type: Application
    Filed: April 23, 2015
    Publication date: August 13, 2015
    Inventors: Tomohisa Sano, Yusuke Hasegawa, Shuichi Hiroko, Yoshitaka Suzumura, Keisuke Tanaka
  • Publication number: 20150227067
    Abstract: A magnetic toner containing a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein when the inorganic fine particles are classified as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles in accordance with fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X of coverage of the magnetic toner surface by the third inorganic fine particles are in prescribed ranges.
    Type: Application
    Filed: April 23, 2015
    Publication date: August 13, 2015
    Inventors: Yusuke Hasegawa, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Keisuke Tanaka
  • Publication number: 20150168859
    Abstract: A magnetic toner contains magnetic toner particles and silica fine particles. The magnetic toner has a thermal conductivity in the range of 0.230 to 0.270 W/(m·K). Primary particles of the silica fine particles have a number-average particle diameter (D1) in the range of 5 to 20 nm. The coverage X1 of the magnetic toner surface by the silica fine particles ranges from 40% to 75% by area as determined using an X-ray photoelectron spectrometer (ESCA). The diffusion index (X1/X2) satisfies the following formula: Diffusion index??0.0042×X1+0.62 wherein X2 denotes the theoretical coverage of the magnetic toner surface by the silica fine particles.
    Type: Application
    Filed: December 11, 2014
    Publication date: June 18, 2015
    Inventors: Takashi Matsui, Yusuke Hasegawa, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
  • Patent number: 9029055
    Abstract: A magnetic toner which has superior charging stability and charging uniformity, maintains stable developing performance without any dependence on service environments and may less cause any decrease in image density and any image defects such as fog and ghost, the magnetic toner has magnetic toner particles, each of the magnetic toner particles has magnetic toner base particle containing a binder resin and a magnetic material, and an inorganic fine powder, (a) the magnetic toner having, at a frequency of 100 kHz and a temperature of 30° C., a dielectric loss factor (??) of 2.5×10?1 pF/m or more and 7.0×10?1 pF/m or less and a dielectric dissipation factor (tan ?L) of 3.0×10?2 or less, (b) the magnetic toner having, in a dielectric dissipation factor (tan ?) thereof at a frequency of 100 kHz, a maximum value (tan ?H) within the temperature range of 60° C. to 140° C.; and the tan ?H and the tan ?L satisfying (tan ?H?tan ?L)?3.0×10?2.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: May 12, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kozue Aoki, Yusuke Hasegawa, Yoshitaka Suzumura
  • Publication number: 20150003872
    Abstract: There are provided an image-forming apparatus that inhibit the occurrence of a longitudinal streak image attributed to a cleaning failure, and a process cartridge. The image-forming apparatus and the process cartridge each have a charging member with a surface having a concavities derived from an opening of the bowl-shaped resin particle, and a protrusions derived from an edge of the opening of the bowl-shaped resin particle, the coverage ratio X1 of a surface of the toner with the silica fine particles is 50.0 area % or more and 75.0 area % or less, and when a theoretical coverage ratio of the toner by the silica fine particles is X2, a diffusion index represented by the formula 1 satisfies the formula 2: diffusion index=X1/X2??(formula 1) diffusion index??0.0042×X1+0.
    Type: Application
    Filed: June 26, 2014
    Publication date: January 1, 2015
    Inventors: Tomohito Taniguchi, Takehiko Aoyama, Taichi Sato, Noboru Miyagawa, Masahiro Watanabe, Atsushi Uematsu, Yoshitaka Suzumura
  • Publication number: 20150003874
    Abstract: There are provided an image forming apparatus in which the generation of lateral streak images due to a decrease in the in-nip discharge intensity is suppressed while at the same time the generation of spot-like images due to abnormal discharge caused by smudges on the surface of a charging member is suppressed, and a process cartridge. The image forming apparatus and the process cartridge each has: a charging member containing a resin particle having a plurality of pores inside thereof; and a toner in which the coverage ratio X1 of a surface of the toner with silica fine particles is 50.0 area % or more and 75.0 area % or less, and when a theoretical coverage ratio with the silica fine particles is X2, a diffusion index represented by formula 1 satisfies formula 2. diffusion index=X1/X2??(formula 1) diffusion index??0.0042×X1+0.
    Type: Application
    Filed: June 26, 2014
    Publication date: January 1, 2015
    Inventors: Takehiko Aoyama, Tomohito Taniguchi, Noboru Miyagawa, Taichi Sato, Atsushi Uematsu, Masahiro Watanabe, Yoshitaka Suzumura
  • Publication number: 20140377696
    Abstract: A toner comprising toner particles which comprise a binder resin and a colorant, and also inorganic fine particles as external additives, wherein the inorganic fine particles are silica fine particles and a group 2 element titanate fine particles, the inorganic fine particles have specific particle diameters, the silica fine particles have a coverage ratio X1 on the surfaces of the toner particles, which is not less than 40.0 surface area % and not more than 75.0 surface area %, when the theoretical coverage ratio by the silica fine particles is X2, the diffusion index defined as “diffusion index=X1/X2” satisfies the condition: diffusion index??0.0042×X1+0.62, and the external additives have an embedding ratio on the toner particles, which satisfies a specific range.
    Type: Application
    Filed: June 13, 2014
    Publication date: December 25, 2014
    Inventors: Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
  • Patent number: 8918035
    Abstract: An object of the present invention is to provide a developing apparatus which can provide images having superior image density and less fogging. The present invention relates to a developing apparatus wherein a magnetic toner-carrying member has a work function value at the surface within a specific range, a toner regulating member which regulates toner carried on the magnetic toner-carrying member is formed by a specific material at a portion contacting the magnetic toner, and has a ratio [W/B] of the amount W of silica fine powder to the theoretical specific surface area B of the magnetic toner satisfying a specific relation.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: December 23, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yusuke Hasegawa, Yoshitaka Suzumura, Kozue Uratani
  • Publication number: 20140370431
    Abstract: A magnetic toner contains magnetic toner particles containing a binder resin, a release agent, and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles, wherein a ratio of coverage of the magnetic toner particles' surface by the inorganic fine particles is in a prescribed range for the magnetic toner, the inorganic fine particles contain prescribed metal oxide fine particles, with at least 85 mass % of the metal oxide fine particles being silica fine particles, the coefficient of variation on the coverage ratio A is in a prescribed range, the binder resin contains a styrene resin, in a GPC measurement of a THF-soluble matter in the magnetic toner, a peak molecular weight (Mp) of a main peak is in a prescribed range, and a prescribed fatty acid ester compound is incorporated as a release agent.
    Type: Application
    Filed: December 26, 2012
    Publication date: December 18, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Shuichi Hiroko, Michihisa Magome, Yusuke Hasegawa, Yoshitaka Suzumura
  • Publication number: 20140322639
    Abstract: A magnetic toner contains magnetic toner particles containing a binder resin, a release agent, and a magnetic body and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles contain metal oxide fine particles, the metal oxide fine particles containing silica fine particles, and optionally containing titania fine particles and alumina fine particles, and a content of the silica fine particles being at least 85 mass % with respect to a total mass of the silica fine particles, the titania fine particles and the alumina fine particles, the coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and the coverage ratio by the inorganic fine particles fixed to the magnetic toner particles' surface reside in a prescribed relationship, the binder resin contains a polyester resin, the release agent contains an ester compound, and an endothermic peak for the magnetic toner
    Type: Application
    Filed: December 26, 2012
    Publication date: October 30, 2014
    Inventors: Yoshitaka Suzumura, Yusuke Hasegawa, Michihisa Magome, Kozue Uratani
  • Patent number: 8778585
    Abstract: A toner with good low-temperature fixability even in light-pressure type fixing units, which causes no contamination of fixing films and provides images having stable image densities and excellent image quality after long-term use. The toner includes a toner particle containing a binder resin, a coloring agent, a release agents (a) and (b) The release agent (a) is a monofunctional or bifunctional ester wax; the release agent (b) is a hydrocarbon wax; a solubility of the release agent (a) into the binder resin is higher than that of the release agent (b). When tetrahydrofuran-soluble components of the toner are subjected to GPC, a proportion of components having a molecular weight of 500 or less is 2.5 area % or less. When the tetrahydrofuran-soluble components at 25° C. are subjected to SEC-MALLS, a weight-average molecular weight Mw thereof is 5,000-100,000, and the Mw and the radius of gyration Rw thereof satisfy 5.0×10?4?Rw/Mw?1.0×10?2.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: July 15, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Matsui, Michihisa Magome, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura