Patents by Inventor Eriko Yanase
Eriko Yanase 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: 8841054Abstract: An image-forming method is provided which can provide stable image density irrespective of use environments and does not cause image defects such as fogging, tailing, or transfer voids, even when being applied to a developing sleeve with a reduced diameter. In the image-forming method, a latent image bearing member and a toner bearing member bearing a magnetic toner on its surface and having inside a unit for generating a magnetic field are placed with a predetermined interval, and an alternating field is applied between the latent image bearing member and the toner bearing member, and an electrostatic latent image borne by the latent image bearing member is developed with the magnetic toner. The toner bearing member has a specific diameter, and the magnetic toner has a specific circularity and a specific compressibility. The total energy of the toner measured with a powder flowability measuring apparatus satisfies a specific value.Type: GrantFiled: October 20, 2008Date of Patent: September 23, 2014Assignee: Canon Kabushiki KaishaInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 8426091Abstract: To solve a thin image density and sweeping occurring when a toner carrying member having a small diameter is used, provided is an image-forming method including: a charging step; an electrostatic latent image-forming step; a developing step; a transferring step; and a fixing step, in which a magnetic toner to be used in the method has a specific weight average particle diameter (D4); the magnetic toner has a specific intensity of magnetization in a specific magnetic field; and a surface free energy of a surface of the magnetic toner and a surface free energy of a surface of a toner carrying member to be used in the method satisfy specific relationships.Type: GrantFiled: October 29, 2008Date of Patent: April 23, 2013Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko
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Patent number: 7935467Abstract: In a magnetic toner which has magnetic toner base particles containing at least a binder resin and a magnetic material, and an inorganic fine powder, (i) the magnetic toner has an average circularity of from 0.950 or more to 1.000 or less, (ii) the magnetic toner has a compressibility of 30 or less, and (iii) the magnetic toner contains boron nitride particles having a median diameter (D50) of from 0.5 ?m or more to 8.0 ?m or less, as the inorganic fine powder in an amount of from 0.05 part by mass or more to 1.00 part by mass or less based on 100 parts by mass of the magnetic toner base particles. This provides a magnetic toner with which stable image density can be achieved without regard to service environment and which do not cause any image defects such as fog.Type: GrantFiled: November 18, 2008Date of Patent: May 3, 2011Assignee: Canon Kabushiki KaishaInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7923190Abstract: In a toner containing at least a binder resin, a colorant, an ester compound and a low-melting material, the ester compound is an ester of dipentaerythritol with a carboxylic acid having 18 or more to 25 or less carbon atoms, and, where the melting point of the ester compound is represented by Tm(A) (° C.) and the melting point of the low-melting material is represented by Tm(B) (° C.), the toner satisfies the relationship of: Tm(B)?Tm(A)+5.Type: GrantFiled: October 13, 2009Date of Patent: April 12, 2011Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7906266Abstract: A magnetic toner is disclosed including magnetic toner particles containing at least a binder resin and a magnetic powder. The magnetic powder contains a specific amount of phosphorus elements, and a specific amount of silicon elements, based on the iron element, with the ratio of the phosphorous element to the silicon elements being in a specific range, and has a specific volume-average particle diameter, a specific saturation magnetization in a specific magnetic field, and a specific residual magnetization. The magnetic toner can realize high image density and reduce fog and spots around line images regardless of environmental variation, and is superior in durability, and besides, can achieve small toner consumption.Type: GrantFiled: May 16, 2005Date of Patent: March 15, 2011Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Eriko Yanase, Tatsuya Nakamura
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Patent number: 7842446Abstract: An object of the present invention is to provide a toner excellent in durability and storage stability, and having good fixing performance in a wide fixing temperature region even at a high process speed. According to the present invention, there is provided a toner containing: a binder resin; a colorant; and a polyester resin, in which: I) the polyester resin contains at least, as a main component, polyester obtained by subjecting a monomer composition containing an alcohol selected from aliphatic diols each having 2 to 22 carbon atoms and a carboxylic acid selected from aliphatic dicarboxylic acids each having 2 to 22 carbon atoms to a polycondensation reaction; and II) a region having a lamellar structure is present at a surface layer of the toner.Type: GrantFiled: September 13, 2005Date of Patent: November 30, 2010Assignee: Canon Kabushiki KaishaInventors: Eriko Yanase, Michihisa Magome, Takashi Matsui, Akira Sakakibara
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Patent number: 7678523Abstract: To provide a magnetic toner which has superior low-temperature fixing performance and pressure roller anti-staining properties even in various forms of use, has been kept from image defects such as image non-uniformity even during long-time image reproduction and can achieve high-level image quality. In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the activation energy Ea (kJ/mol) that is determined from a shift factor aT120 in a master curve of the toner, prepared when 120° C. is set as reference temperature, and the activation energy Eb (kJ/mol) that is determined from a shift factor aT150 in a master curve of the toner, prepared when 150° C. is set as reference temperature, satisfy Expression (1), and the Ea is 110 kJ/mol or less: 1.00?Ea/Eb<1.20??(1).Type: GrantFiled: December 9, 2008Date of Patent: March 16, 2010Assignee: Canon Kabushiki KaishaInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara
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Publication number: 20100028795Abstract: In a toner containing at least a binder resin, a colorant, an ester compound and a low-melting material, the ester compound is an ester of dipentaerythritol with a carboxylic acid having 18 or more to 25 or less carbon atoms, and, where the melting point of the ester compound is represented by Tm(A) (° C.) and the melting point of the low-melting material is represented by Tm(B) (° C.), the toner satisfies the relationship of: Tm(B)?Tm(A)+5.Type: ApplicationFiled: October 13, 2009Publication date: February 4, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Publication number: 20090197192Abstract: A magnetic toner having magnetic toner particles containing at least a binder resin and a magnetic material, wherein, in the test of dissolution level of the magnetic material, the dissolution percentages S3 (% by mass), S15 (% by mass) and S30 (% by mass), and the dissolution level proportion Sc satisfy the following expressions: 0.5?S3?10, 40?S15?80, 1.2?Sc[=(S15?S3)/(S30?S15)]?10; and the magnetic toner has a dielectric loss factor (tan ?) at 25° C. and at a frequency 1.0×104 Hz, within the range of from 2.0×10?3 or more to 1.5×10?2 or less.Type: ApplicationFiled: April 9, 2009Publication date: August 6, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Yoshitaka Suzumura
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Patent number: 7560212Abstract: The present invention provides a magnetic toner which is hardly influenced by an environment, and with which an image with high quality and excellent resolution can be stably even under low humidity. In the magnetic toner of present invention: I) a ratio of an iron element content to a carbon element content present on the toner particle surface is less than 0.0010; II) 50 number % or more of toner particles satisfy a relationship of D/C?0.02 (C: projected area diameter of toner particles, D: minimum value for a distance between a magnetic iron oxide fine particle and the toner particle surface); and III) 40-95 number % of toner particles satisfy a structure where 70 number % or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 time as far as C from the toner particle surface.Type: GrantFiled: March 18, 2008Date of Patent: July 14, 2009Assignee: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Michihisa Magome, Eriko Yanase, Takeshi Kaburagi
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Publication number: 20090130580Abstract: In a magnetic toner which has magnetic toner base particles containing at least a binder resin and a magnetic material, and an inorganic fine powder, (i) the magnetic toner has an average circularity of from 0.950 or more to 1.000 or less, (ii) the magnetic toner has a compressibility of 30 or less, and (iii) the magnetic toner contains boron nitride particles having a median diameter (D50) of from 0.5 ?m or more to 8.0 ?m or less, as the inorganic fine powder in an amount of from 0.05 part by mass or more to 1.00 part by mass or less based on 100 parts by mass of the magnetic toner base particles. This provides a magnetic toner with which stable image density can be achieved without regard to service environment and which do not cause any image defects such as fog.Type: ApplicationFiled: November 18, 2008Publication date: May 21, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Publication number: 20090117477Abstract: To solve a thin image density and sweeping occurring when a toner carrying member having a small diameter is used, provided is an image-forming method including: a charging step; an electrostatic latent image-forming step; a developing step; a transferring step; and a fixing step, in which a magnetic toner to be used in the method has a specific weight average particle diameter (D4); the magnetic toner has a specific intensity of magnetization in a specific magnetic field; and a surface free energy of a surface of the magnetic toner and a surface free energy of a surface of a toner carrying member to be used in the method satisfy specific relationships.Type: ApplicationFiled: October 29, 2008Publication date: May 7, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko
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Publication number: 20090092919Abstract: To provide a magnetic toner which has superior low-temperature fixing performance and pressure roller anti-staining properties even in various forms of use, has been kept from image defects such as image non-uniformity even during long-time image reproduction and can achieve high-level image quality. In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the activation energy Ea (kJ/mol) that is determined from a shift factor aT120 in a master curve of the toner, prepared when 120° C. is set as reference temperature, and the activation energy Eb (kJ/mol) that is determined from a shift factor aT150 in a master curve of the toner, prepared when 150° C. is set as reference temperature, satisfy Expression (1), and the Ea is 110 kJ/mol or less: 1.00?Ea/Eb<1.20??(1).Type: ApplicationFiled: December 9, 2008Publication date: April 9, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara
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Publication number: 20090047043Abstract: An image-forming method is provided which can provide stable image density irrespective of use environments and does not cause image defects such as fogging, tailing, or transfer voids, even when being applied to a developing sleeve with a reduced diameter. In the image-forming method, a latent image bearing member and a toner bearing member bearing a magnetic toner on its surface and having inside a unit for generating a magnetic field are placed with a predetermined interval, and an alternating field is applied between the latent image bearing member and the toner bearing member, and an electrostatic latent image borne by the latent image bearing member is developed with the magnetic toner. The toner bearing member has a specific diameter, and the magnetic toner has a specific circularity and a specific compressibility. The total energy of the toner measured with a powder flowability measuring apparatus satisfies a specific value.Type: ApplicationFiled: October 20, 2008Publication date: February 19, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7452649Abstract: A magnetic toner is provided having at last a binder resin and a magnetic material and having a weight-average particle diameter of 3 ?m to 10 ?m. The magnetic material has been surface-treated with a low-softening substance (A), and has a compressibility of 35 or more which can be calculated according to a specific expression. The softening point of the magnetic toner is from 40° C. to 85° C. in measurement by a flow tester. The magnetic toner has a resin component containing 1% to 60% by weight of a tetrahydrofuran-insoluble matter. This magnetic toner is superior in low-temperature fixing performance and has good fixing performance in a broad fixing range.Type: GrantFiled: September 9, 2004Date of Patent: November 18, 2008Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Eriko Yanase, Atsushi Tani
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Publication number: 20080171277Abstract: The present invention provides a magnetic toner which is hardly influenced by an environment, and with which an image with high quality and excellent resolution can be stably even under low humidity. In the magnetic toner of present invention: I) a ratio of an iron element content to a carbon element content present on the toner particle surface is less than 0.0010; II) 50 number % or more of toner particles satisfy a relationship of D/C?0.02 (C: projected area diameter of toner particles, D: minimum value for a distance between a magnetic iron oxide fine particle and the toner particle surface); and III) 40-95 number % of toner particles satisfy a structure where 70 number % or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 time as far as C from the toner particle surface.Type: ApplicationFiled: March 18, 2008Publication date: July 17, 2008Applicant: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Michihisa Magome, Eriko Yanase, Takeshi Kaburagi
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Patent number: 7371494Abstract: The present invention provides a magnetic toner which is hardly influenced by an environment, and with which an image with high quality and excellent resolution can be stably even under low humidity. In the magnetic toner of present invention: I) a ratio of an iron element content to a carbon element content present on the toner particle surface is less than 0.0010; II) 50 number % or more of toner particles satisfy a relationship of D/C?0.02 (C: projected area diameter of toner particles, D: minimum value for a distance between a magnetic iron oxide fine particle and the toner particle surface); and III) 40-95 number % of toner particles satisfy a structure where 70 number % or more of the magnetic iron oxide fine particles in the respective toner particles are present up to a depth of 0.2 time as far as C from the toner particle surface.Type: GrantFiled: September 13, 2004Date of Patent: May 13, 2008Assignee: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Michihisa Magome, Eriko Yanase, Takeshi Kaburagi
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Patent number: 7361442Abstract: A developing method is provided in which a developer is carried on a developer carrying member, a thin layer of the developer is formed thereon and a latent image on a latent image bearing member is developed with a developer. The developer is composed of magnetic toner particles containing a binder resin and a magnetic powder. The magnetic powder has a saturation magnetization of 67.0 Am2/kg to 75.0 Am2/kg in a magnetic field of 79.6 kA/m (1,000 oersteds) and has a residual magnetization of 4.5 Am2/kg or less. In the surface profile of the conductive resin coat layer of the developer carrying member, the relationship 1.00?S/A?1.65 is satisfied where S is a surface area of regions zoned by an area A of microscopic unevenness regions from which parts exceeding a reference plane by 0.5×r (r: weight average particle diameter (?m) of a toner used) or more have been excluded.Type: GrantFiled: April 17, 2007Date of Patent: April 22, 2008Assignee: Canon Kabushiki KaishaInventors: Satoshi Otake, Masayoshi Shimamura, Yusutaka Akashi, Kazunori Saiki, Nene Dojo, Minoru Ito, Michihisa Magome, Eriko Yanase, Tatsuya Nakamura
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Publication number: 20070238043Abstract: A developing method is provided in which a developer is carried on a developer carrying member, a thin layer of the developer is formed thereon and a latent image on a latent image bearing member is developed with a developer. The developer is composed of magnetic toner particles containing a binder resin and a magnetic powder. The magnetic powder has a saturation magnetization of 67.0 Am2/kg to 75.0 Am2/kg in a magnetic field of 79.6 kA/m (1,000 oersteds) and has a residual magnetization of 4.5 Am2/kg or less. In the surface profile of the conductive resin coat layer of the developer carrying member, the relationship 1.00?S/A?1.65 is satisfied where S is a surface area of regions zoned by an area A of microscopic unevenness regions from which parts exceeding a reference plane by 0.5×r (r: weight average particle diameter (?m) of a toner used) or more have been excluded.Type: ApplicationFiled: April 17, 2007Publication date: October 11, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Satoshi Otake, Masayoshi Shimamura, Yusutaka Akashi, Kazunori Saiki, Nene Dojo, Minoru Ito, Michihisa Magome, Eriko Yanase, Tatsuya Nakamura
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Publication number: 20060188800Abstract: A magnetic toner is disclosed including magnetic toner particles containing at least a binder resin and a magnetic powder. The magnetic powder contains a specific amount of phosphorus elements, and a specific amount of silicon elements, based on the iron element, with the ratio of the phosphorous element to the silicon elements being in a specific range, and has a specific volume-average particle diameter, a specific saturation magnetization in a specific magnetic field, and a specific residual magnetization. The magnetic toner can realize high image density and reduce fog and spots around line images regardless of environmental variation, and is superior in durability, and besides, can achieve small toner consumption.Type: ApplicationFiled: May 16, 2005Publication date: August 24, 2006Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Eriko Yanase, Tatsuya Nakamura