Patents by Inventor Yusuke Hasegawa
Yusuke Hasegawa 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).
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Patent number: 9213251Abstract: The magnetic toner contains: magnetic toner particles containing a binder resin 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 comprise strontium titanate fine particles and metal oxide fine particles, and 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. In addition, the magnetic toner has a characteristic state of coverage, by the inorganic fine particles, of the magnetic toner particle surface, and the ratio [D4/D1] of the weight-average particle diameter (D4) to the number-average particle diameter (D1) is in a prescribed range.Type: GrantFiled: January 31, 2013Date of Patent: December 15, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Atsuhiko Ohmori, Michihisa Magome, Yusuke Hasegawa, Keisuke Tanaka
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Patent number: 9213250Abstract: 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: GrantFiled: September 30, 2013Date of Patent: December 15, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori
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Patent number: 9152065Abstract: A magnetic toner includes: magnetic toner particles containing a binder resin and a magnetic body; and inorganic fine particles that are present on the surface of the magnetic toner particles and are not a magnetic iron oxide and magnetic iron oxide particles that are 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; when a coverage ratio A (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and a coverage ratio B (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles thType: GrantFiled: January 31, 2013Date of Patent: October 6, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Tomohisa Sano, Michihisa Magome, Yusuke Hasegawa, Atsuhiko Ohmori
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Publication number: 20150227067Abstract: 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: ApplicationFiled: April 23, 2015Publication date: August 13, 2015Inventors: Yusuke Hasegawa, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Keisuke Tanaka
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Publication number: 20150227068Abstract: 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: ApplicationFiled: April 23, 2015Publication date: August 13, 2015Inventors: Tomohisa Sano, Yusuke Hasegawa, Shuichi Hiroko, Yoshitaka Suzumura, Keisuke Tanaka
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Patent number: 9097997Abstract: A magnetic toner is provided that exhibits an excellent electrostatic offset resistance both initially and after long-term use. The magnetic toner contains: magnetic toner particles containing a binder resin 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 a prescribed metal oxide fine particle in a prescribed proportion; the magnetic toner has prescribed numerical value ranges for a coverage ratio A of the magnetic toner particle surface covered by the inorganic fine particles and for a coverage ratio B by the inorganic fine particles that are fixed to the magnetic toner particle surface; the magnetic toner particle contains a crystalline polyester; and measurement of the magnetic toner with a differential scanning calorimeter provides a characteristic differential scanning calorimetric curve.Type: GrantFiled: January 31, 2013Date of Patent: August 4, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Michihisa Magome, Yusuke Hasegawa, Takashi Matsui
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Publication number: 20150168859Abstract: 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: ApplicationFiled: December 11, 2014Publication date: June 18, 2015Inventors: Takashi Matsui, Yusuke Hasegawa, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
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Patent number: 9029055Abstract: 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: GrantFiled: May 25, 2011Date of Patent: May 12, 2015Assignee: Canon Kabushiki KaishaInventors: Kozue Aoki, Yusuke Hasegawa, Yoshitaka Suzumura
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Publication number: 20140377696Abstract: 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: ApplicationFiled: June 13, 2014Publication date: December 25, 2014Inventors: Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori, Keisuke Tanaka
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Patent number: 8918035Abstract: 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: GrantFiled: December 21, 2012Date of Patent: December 23, 2014Assignee: Canon Kabushiki KaishaInventors: Yusuke Hasegawa, Yoshitaka Suzumura, Kozue Uratani
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Publication number: 20140370431Abstract: 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: ApplicationFiled: December 26, 2012Publication date: December 18, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Shuichi Hiroko, Michihisa Magome, Yusuke Hasegawa, Yoshitaka Suzumura
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Publication number: 20140342277Abstract: The magnetic toner contains: magnetic toner particles containing a binder resin 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 comprise strontium titanate fine particles and metal oxide fine particles, and 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. In addition, the magnetic toner has a characteristic state of coverage, by the inorganic fine particles, of the magnetic toner particle surface, and the ratio [D4/D1] of the weight-average particle diameter (D4) to the number-average particle diameter (D1) is in a prescribed range.Type: ApplicationFiled: January 31, 2013Publication date: November 20, 2014Inventors: Atsuhiko Ohmori, Michihisa Magome, Yusuke Hasegawa, Keisuke Tanaka
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Publication number: 20140342278Abstract: A magnetic toner includes: magnetic toner particles containing a binder resin and a magnetic body; and inorganic fine particles that are present on the surface of the magnetic toner particles and are not a magnetic iron oxide and magnetic iron oxide particles that are 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; when a coverage ratio A (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and a coverage ratio B (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles thType: ApplicationFiled: January 31, 2013Publication date: November 20, 2014Inventors: Tomohisa Sano, Michihisa Magome, Yusuke Hasegawa, Atsuhiko Ohmori
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Publication number: 20140335450Abstract: A magnetic toner is provided that exhibits an excellent electrostatic offset resistance both initially and after long-term use. The magnetic toner contains: magnetic toner particles containing a binder resin 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 a prescribed metal oxide fine particle in a prescribed proportion; the magnetic toner has prescribed numerical value ranges for a coverage ratio A of the magnetic toner particle surface covered by the inorganic fine particles and for a coverage ratio B by the inorganic fine particles that are fixed to the magnetic toner particle surface; the magnetic toner particle contains a crystalline polyester; and measurement of the magnetic toner with a differential scanning calorimeter provides a characteristic differential scanning calorimetric curve.Type: ApplicationFiled: January 31, 2013Publication date: November 13, 2014Inventors: Shotaro Nomura, Michihisa Magome, Yusuke Hasegawa, Takashi Matsui
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Publication number: 20140335449Abstract: A magnetic toner including: magnetic toner particles containing a binder resin, a magnetic body, and a release agent; 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, wherein the magnetic toner has a coverage ratio A of the magnetic toner particles' surface by the inorganic fine particles and a coverage ratio B of the magnetic toner particles' surface by the inorganic fine particles fixed to the magnetic toner particles' surface that reside in prescribed numerical value ranges; the binder resin contains a styrene resin; the reType: ApplicationFiled: January 31, 2013Publication date: November 13, 2014Inventors: Kozue Uratani, Michihisa Magome, Yusuke Hasegawa, Shuichi Hiroko
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Publication number: 20140322640Abstract: A magnetic toner containing: magnetic toner particles containing a binder resin 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 silica fine particles and alumina fine particles and/or titania fine particles; a coverage ratio A of the magnetic toner particles' surface by the inorganic fine particles each of which has a particle diameter of from 5 nm to not more than 50 nm and a coverage ratio B of the magnetic toner particles' surface by the inorganic fine particles each of which has a particle diameter of from at least 5 nm to not more than 50 nm and is fixed to the magnetic toner particles' surface, have prescribed values and a prescribed relationship in the magnetic toner; and alumina fine particles and/or titania fine particles each of which has a particle diameter of from at least 100 nm to not more than 800 nm is present on the surface of the magnetType: ApplicationFiled: January 31, 2013Publication date: October 30, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Keisuke Tanaka, Michihisa Magome, Yusuke Hasegawa, Tomohisa Sano
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Publication number: 20140322639Abstract: 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 tonerType: ApplicationFiled: December 26, 2012Publication date: October 30, 2014Inventors: Yoshitaka Suzumura, Yusuke Hasegawa, Michihisa Magome, Kozue Uratani
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Publication number: 20140315126Abstract: The magnetic toner includes magnetic toner particles comprising a binder resin 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 comprise 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, wherein; when a coverage ratio A (%) is a coverage ratio of the magnetic toner particle's surface by the inorganic fine particles and a coverage ratio B (%) is a coverage ratio of the magnetic toner particle' surface by the inorganic fine particles that are fixed to the magnetic toner particle's surface, the magnetic toner has a coverage ratio A, a coefficient of variation on theType: ApplicationFiled: December 26, 2012Publication date: October 23, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Tadashi Dojo, Yusuke Hasegawa
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Publication number: 20140315125Abstract: The magnetic toner contains magnetic toner particles containing a binder resin 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 comprise metal oxide fine particles, wherein 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. In addition, the coverage ratio of the magnetic toner particle surface by the inorganic fine particles resides in a prescribed range for this magnetic toner; the binder resin is a styrene resin; the weight-average molecular weight and radius of gyration of the magnetic toner reside in a prescribed relationship; and the viscosity of the magnetic toner at 110° C.Type: ApplicationFiled: December 26, 2012Publication date: October 23, 2014Inventors: Takashi Matsui, Yusuke Hasegawa, Shotaro Nomura, Michihisa Magome
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Publication number: 20140302433Abstract: A magnetic toner contains magnetic toner particles containing a binder resin 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, when a coverage ratio A (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles and a coverage ratio B (%) is a coverage ratio of the magnetic toner particles' surface by the inorganic fine particles that are fixed to the magnetic toner particles' surface, the magnetic toner has a coverage ratio A and a coverage ratio B/coverage ratio A in prType: ApplicationFiled: December 26, 2012Publication date: October 9, 2014Inventors: Yusuke Hasegawa, Tadashi Dojo, Michihisa Magome