Patents by Inventor Takayuki Itakura
Takayuki Itakura 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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Publication number: 20130244164Abstract: A toner having toner particles, each of which contains a binder resin, a wax and inorganic fine particles, wherein the inorganic fine particles are fixed at the surface of the toner particles as a result of a surface treatment by hot air, and the degree of uneven distribution of wax in the toner is controlled in a depth direction of the toner, from the toner surface towards a toner central portion.Type: ApplicationFiled: November 24, 2011Publication date: September 19, 2013Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Kosuke Fukudome, Yoshiaki Shiotari, Takayuki Itakura
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Publication number: 20130236830Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.Type: ApplicationFiled: April 30, 2013Publication date: September 12, 2013Applicant: CANON KABUSHIKI KAISHAInventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
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Publication number: 20130171556Abstract: An object of the present invention is to improve resistance to wraparound during fixing while achieving both low-temperature fixability and resistance to hot offset. A further object is to suppress image density variations and fogging in white background regions during use at high print coverage rate at high temperature and high humidity. A toner containing inorganic fine particles and toner particles containing a binder resin and a wax being provided, the toner being characterized in that the binder resin contains a polyester resin A obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aromatic diol and a polyester resin B obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aliphatic diol, and in that the degree of segregation of the wax in the toner depth direction from the toner surface toward the toner center is controlled.Type: ApplicationFiled: September 15, 2011Publication date: July 4, 2013Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Koh Ishigami, Kentaro Kamae, Takayuki Itakura
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Patent number: 8455167Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.Type: GrantFiled: December 10, 2010Date of Patent: June 4, 2013Assignee: Canon Kabushiki KaishaInventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
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Patent number: 8288069Abstract: Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10?3 N/m or more and 1.0×10?1 N/m or less: I=P?/(A×B×106)??Eq. (1) where I represents the surface tension index (N/m) of the toner, P? represents a capillary pressure (N/m2) of the toner for the 45-vol % aqueous solution of methanol, A represents a specific surface area (m2/g) of the toner, and B represents a true density (g/cm3) of the toner.Type: GrantFiled: November 5, 2010Date of Patent: October 16, 2012Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Takeshi Ohtsu, Takayuki Itakura
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Publication number: 20120094225Abstract: A two-component developer containing a cyan toner and a magnetic carrier, the cyan toner having the following characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: October 17, 2011Publication date: April 19, 2012Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 8142972Abstract: Provided is a developer for replenishment capable of forming a high-quality image even upon duration. The developer for replenishment includes at least a toner and a magnetic carrier, and in the developer for replenishment, 1 part by mass of the magnetic carrier is blended with 2 to 50 parts by mass of the toner, and the magnetic carrier contains a ferrite core and a resin component, has a true specific gravity of 2.5 to 4.2 g/cm3, has a 50% particle diameter on a volume basis (D50) of 15 to 70 ?m, and has an average circularity of 0.850 to 0.950, the average circularity having a coefficient of variation of 1.0 to 10.0%.Type: GrantFiled: December 5, 2006Date of Patent: March 27, 2012Assignee: Canon Kabushiki KaishaInventors: Yojiro Hotta, Kazuo Terauchi, Kunihiko Nakamura, Hiroyuki Fujikawa, Yoshinobu Baba, Takayuki Itakura, Hirohide Tanikawa
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Patent number: 8137886Abstract: A magnetic carrier is provided which uses a toner having high coloring power and enables development to be performed at low electric field intensity and can form high quality images while keeping gradation characteristics. The magnetic carrier includes magnetic carrier particles including at least porous magnetic core particles and a resin. The electric field intensity just before the break-down of the magnetic carrier is 1,300 V/cm or more and 5,000 V/cm or less.Type: GrantFiled: January 21, 2010Date of Patent: March 20, 2012Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Koh Ishigami, Tomoko Endo, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Chika Inoue, Takayuki Itakura
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Patent number: 8114562Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: March 3, 2010Date of Patent: February 14, 2012Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 7983581Abstract: A fixing method and a fixing device is provided in which an unfixed toner image formed on a recording medium is heat-pressure-fixed by using a fixing unit, wherein the unfixed toner image is fixed when the recording medium passes through at least two fixing units arranged in series in a conveying direction of the recording medium. Specific relations are satisfied between a maximum temperature on the recording medium when the recording medium passes through a first fixing unit, a maximum temperature on the recording medium when the recording medium passes through a second fixing unit, a minimum temperature on the recording medium during a time period commencing on ejection of the recording medium from the first fixing unit and ending on entry of the recording medium into the second fixing unit and properties of the toner.Type: GrantFiled: April 26, 2005Date of Patent: July 19, 2011Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Naoki Okamoto, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20110143277Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.Type: ApplicationFiled: December 10, 2010Publication date: June 16, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
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Publication number: 20110136060Abstract: Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10?3 N/m or more and 1.0×10?1 N/m or less: I=P?/(A×B×106)??Eq. (1) where I represents the surface tension index (N/m) of the toner, P? represents a capillary pressure (N/m2) of the toner for the 45-vol % aqueous solution of methanol, A represents a specific surface area (m2/g) of the toner, and B represents a true density (g/cm3) of the toner.Type: ApplicationFiled: November 5, 2010Publication date: June 9, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Takeshi Ohtsu, Takayuki Itakura
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Patent number: 7939233Abstract: A magnetic carrier and a two-component developer are provided which have remedied blank areas, fog after leaving, carrier sticking during running, and image density variations before and after running. The magnetic carrier has magnetic carrier particles having at least porous magnetic core particles and a resin. The magnetic carrier particles satisfying the specific conditions (a), (b) and (c) where, in a reflected electron image of cross sections of the magnetic carrier particles as photographed with a scanning electron microscope, straight lines that divide a cross section of a magnetic carrier particle into 72 at intervals of 5° are drawn from a reference point of the cross section thereof toward the surface of the magnetic carrier particle; the magnetic carrier particles being contained in an amount of 60% by number or more.Type: GrantFiled: January 21, 2010Date of Patent: May 10, 2011Assignee: Canon Kabushiki KaishaInventors: Chika Inoue, Hiroyuki Fujikawa, Koh Ishigami, Kunihiko Nakamura, Nozomu Komatsu, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20110097661Abstract: An object of the present invention is to provide a two-component developer which can achieve a high-definition image with a smaller toner laid-on level than a conventional one, provides a color gamut comparable to that of printing, can respond to an increase in printing speed, and allows an image with a stable tinge to be formed even in long-term use. The object can be achieved by a two-component developer containing a cyan toner and a magnetic carrier, the two-component developer being characterized in that the cyan toner has the following characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.Type: ApplicationFiled: October 25, 2010Publication date: April 28, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 7927775Abstract: Provided is a magnetic carrier giving a high quality image free of density variation without the occurrence of fogging or carrier adhesion and having excellent dot reproducibility even during long-term use. The magnetic carrier has magnetic carrier particles produced by filling pores of porous magnetic core particles with a resin. The magnetic carrier contains 80% by number or more of the magnetic carrier particles satisfying the specific conditions (a) and (b) when 18 straight lines passing through a reference point of a cross section of the magnetic carrier particle are drawn at intervals of 10° in a reflected electron image of the cross section of the magnetic carrier particle photographed by a scanning electron microscope.Type: GrantFiled: January 21, 2010Date of Patent: April 19, 2011Assignee: Canon Kabushiki KaishaInventors: Nozomu Komatsu, Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Chika Inoue, Yoshinobu Baba, Takayuki Itakura, Tomoko Endo
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Patent number: 7906262Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: March 3, 2010Date of Patent: March 15, 2011Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 7858283Abstract: A magnetic carrier which has magnetic carrier particles each having at least porous magnetic core particles and a resin, in which, in a backscattered electron image of the magnetic carrier particles, photographed with a scanning electron microscope as taken at an accelerating voltage of 2.0 kV, magnetic carrier particles having area proportion S1 found from a specific expression (1) of from 0.5 area % or more to 8.0 area % or less are in a proportion of 8.0% by number or more in the magnetic carrier, an average proportion Av1 of the total area of portions having a high luminance which come from a metal oxide on the magnetic carrier particles to the total projected area of the magnetic carrier particles is from 0.5 area % or more to 8.0 area % or less, and an average proportion Av2 found from a specific expression (2) is 10.0 area % or less.Type: GrantFiled: January 21, 2010Date of Patent: December 28, 2010Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Chika Inoue, Tomoko Endo, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20100248126Abstract: A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 35.0?L*?45.0 and 60.0?C*?72.0; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: June 9, 2010Publication date: September 30, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Publication number: 20100203438Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: March 3, 2010Publication date: August 12, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
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Patent number: 7767370Abstract: A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the magenta toner determined in a powder state satisfy the relationships of 35?L*?45 and 60?C*?72; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: July 29, 2008Date of Patent: August 3, 2010Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo