Patents by Inventor Hirohide Tanikawa
Hirohide Tanikawa 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: 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: 7816063Abstract: The present invention relates to a toner which has good property such as fixability, coloring power, developability, durability, and environmental stability and so on. More specifically, the present invention relates to a color toner containing at least a binder resin, a colorant, and a wax, in which: a wax concentration of an extract obtained by dispersing the toner into n-hexane at a concentration of 15 mg/cm3 at 23° C. and by subjecting the resultant dispersion to extraction treatment at 23° C. for 1 minute is in the range of 0.080 to 0.500 mg/cm3; an average circularity of particles each having a circle-equivalent diameter of 3 ?m or more in the toner is in the range of 0.925 to 0.965; and a content of the wax is in the range of 1 to 15 parts by mass with respect to 100 parts by mass of the binder resin.Type: GrantFiled: February 6, 2009Date of Patent: October 19, 2010Assignee: Canon Kabushiki KaishaInventors: Akira Hashimoto, Yojiro Hotta, Wakashi Iida, Kazuhiko Hayami, Hirohide Tanikawa, Yasuhiro Ichikawa
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Patent number: 7611813Abstract: Provided a toner including at least: toner particles each containing at least a binder resin, a release agent, and a colorant; and an inorganic fine powder, in which: a degree of aggregation Y1 at a time of compression (200 kpa) of the toner satisfies a relationship of 15?Y1?35, and a degree of aggregation Y2 at a time of non-compression of the toner satisfies a relationship of 7?Y2?15; and a highest endothermic peak of the toner is present in a temperature range of 30 to 200° C. in an endothermic curve measured with a differential scanning calorimeter (DSC), and a peak temperature Tsc (° C.) of the highest endothermic peak satisfies a relationship of 60?Tsc?130.Type: GrantFiled: January 30, 2007Date of Patent: November 3, 2009Assignee: Canon Kabushiki KaishaInventors: Tetsuya Ida, Takeshi Ootsu, Koh Ishigami, Naoki Okamoto, Nozomu Komatsu, Noriyoshi Umeda, Yoshinobu Baba, Takayuki Itakura, Takeshi Naka, Hirohide Tanikawa
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Patent number: 7544457Abstract: The present invention relates to a toner which has good property such as fixability, coloring power, developability, durability, and environmental stability and so on. More specifically, the present invention relates to a color toner containing at least a binder resin, a colorant, and a wax, in which: a wax concentration of an extract obtained by dispersing the toner into n-hexane at a concentration of 15 mg/cm3 at 23° C. and by subjecting the resultant dispersion to extraction treatment at 23° C. for 1 minute is in the range of 0.080 to 0.500 mg/cm3; an average circularity of particles each having a circle-equivalent diameter of 3 ?m or more in the toner is in the range of 0.925 to 0.965; and a content of the wax is in the range of 1 to 15 parts by mass with respect to 100 parts by mass of the binder resin.Type: GrantFiled: November 4, 2004Date of Patent: June 9, 2009Assignee: Canon Kabushiki KaishaInventors: Akira Hashimoto, Yojiro Hotta, Wakashi Iida, Kazuhiko Hayami, Yasuhiro Ichikawa, Hirohide Tanikawa
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Publication number: 20090142683Abstract: The present invention relates to a toner which has good property such as fixability, coloring power, developability, durability, and environmental stability and so on. More specifically, the present invention relates to a color toner containing at least a binder resin, a colorant, and a wax, in which: a wax concentration of an extract obtained by dispersing the toner into n-hexane at a concentration of 15 mg/cm3 at 23° C. and by subjecting the resultant dispersion to extraction treatment at 23° C. for 1 minute is in the range of 0.080 to 0.500 mg/cm3; an average circularity of particles each having a circle-equivalent diameter of 3 ?m or more in the toner is in the range of 0.925 to 0.965; and a content of the wax is in the range of 1 to 15 parts by mass with respect to 100 parts by mass of the binder resin.Type: ApplicationFiled: February 6, 2009Publication date: June 4, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Akira Hashimoto, Yojiro Hotta, Wakashi Iida, Kazuhiko Hayami, Yasuhiro Ichikawa, Hirohide Tanikawa
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Publication number: 20090123856Abstract: 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: ApplicationFiled: December 5, 2006Publication date: May 14, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Yojiro Hotta, Kazuo Terauchi, Kunihiko Nakamura, Hiroyuki Fujikawa, Yoshinobu Baba, Takayuki Itakura, Hirohide Tanikawa
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Patent number: 7455947Abstract: The present invention provides a yellow toner which is excellent in transparency of an image formed on an OHP sheet, excellent in color reproducibility even when a light-pressure fixing unit is employed, excellent in coloring power and charge property, and is reduced in occurrence of filming. The present invention also provides a yellow toner having excellent durability and capable of contributing to the simplification or miniaturization of the constitution of an image forming apparatus. The yellow toner of the invention comprises a binder resin and a colorant, the binder resin contains at least a polyester unit, and the toner in the powder state has a lightness L* satisfying the relationship of L*>87 and has a chromaticity b* satisfying the relationship of 106<b*<120.Type: GrantFiled: May 24, 2007Date of Patent: November 25, 2008Assignee: Canon Kabushiki KaishaInventors: Tetsuya Ida, Yasuhiro Ichikawa, Wakashi Iida, Yojiro Hotta, Kazuhiko Hayami, Hirohide Tanikawa
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Patent number: 7452647Abstract: A color toner that comprises at least a binder resin, a colorant and a release agent, wherein the binder resin has at least a polyester unit and is synthesized in the presence of a tin compound as a catalyst represented by the general formula (1): (RCOO)2Sn??(1) wherein, R is an alkyl group of 5 to 15 carbon atoms. The toner is excellent in charge build-up, resistance to high temperature offset, color reproducibility and transparency.Type: GrantFiled: April 6, 2004Date of Patent: November 18, 2008Assignee: Canon Kabushiki KaishaInventors: Kazuhiko Hayami, Hirohide Tanikawa, Tetsuya Ida, Akira Hashimoto, Nozomu Komatsu, Hiroyuki Fujikawa
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Patent number: 7442478Abstract: A magenta toner is provided which contains at least a binder resin, a colorant, and a wax, in which a maximum heat-absorption peak temperature as measured using a differential scanning calorimeter, a reflectance at a predetermined wavelength when measured in a powder state by spectroscopic analysis, and lightness when measured in a powder form are in specific ranges. A full-color image is formed using the magenta toner as a pale magenta toner in combination with a deep magenta toner. According to the present invention, it becomes possible to form a vivid image which has reduced graininess and roughness from a low-density region to a high-density region, ensures a sufficient fixing temperature region, has a color reproduction range wider that the conventional one, and has high transparency on an OHP sheet.Type: GrantFiled: March 30, 2007Date of Patent: October 28, 2008Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Yuko Sato, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Hirohide Tanikawa
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Patent number: 7396626Abstract: The present invention provides a toner improved in dispersibility of a colorant in the toner particles and excellent in the color reproducibility including color mixability and transparency. The toner is also excellent in the stability in long-term of the chargeability and capable of forming images maintaining high image quality. The present invention provides a toner for forming a full-color image which includes at least toner particles containing a binder resin, a colorant and a wax, and inorganic fine particles, wherein the binder resin comprises a resin having polyester units which is synthesized by use of an aromatic carboxylic acid titanium compound as a catalyst, and the inorganic fine particles comprise fine titanium oxide particles.Type: GrantFiled: September 14, 2005Date of Patent: July 8, 2008Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Fujikawa, Nobuyoshi Sugahara, Takayuki Itakura, Naoki Okamoto, Koh Ishigami, Yoshinobu Baba, Hirohide Tanikawa
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Publication number: 20080026313Abstract: An image forming apparatus includes an electrophotographic photosensitive member and a toner. The photosensitive member has a universal hardness of 1.5×108 to 2.3×108 N/m2, the hardness being measured in an environment of 25° C. with a humidity of 50% using a Vickers diamond indenter having a quadrangular pyramid shape with a maximum load of 6 mN, and has an elastic deformation ratio of 46% to 65%. The toner has a weight average particle diameter of 4.0 to 8.0 ?m, the average circularity of the toner having an equivalent circle diameter of at least 2 ?m is 0.915 to 0.950, the toner has a storage modulus at 80° C. of 1×105 to 1×108 Pa, and a ratio of a loss modulus G? of the toner to the storage modulus G? of the toner (G?/G?=tan ?) is equal to 1 at a temperature in the range of 60° C. to 72° C.Type: ApplicationFiled: October 1, 2007Publication date: January 31, 2008Applicant: CANON KABUSHIKI KAISHAInventors: Nobuyoshi Sugahara, Takayuki Itakura, Koh Ishigami, Hiroyuki Fujikawa, Takakuni Kobori, Hirohide Tanikawa
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Patent number: 7320850Abstract: A magenta toner is provided which contains at least a binder resin, a colorant, and a wax, in which a maximum heat-absorption peak temperature as measured using a differential scanning calorimeter, a reflectance at a predetermined wavelength when measured in a powder state by spectroscopic analysis, and lightness when measured in a powder form are in specific ranges. A full-color image is formed using the magenta toner as a pale magenta toner in combination with a deep magenta toner. According to the present invention, it becomes possible to form a vivid image which has reduced graininess and roughness from a low-density region to a high-density region, ensures a sufficient fixing temperature region, has a color reproduction range wider that the conventional one, and has high transparency on an OHP sheet.Type: GrantFiled: July 14, 2004Date of Patent: January 22, 2008Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Yuko Sato, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Hirohide Tanikawa
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Patent number: 7288348Abstract: In a color toner having toner particles which have toner base particles containing a binder resin, a colorant and a wax, and inorganic fine particles, (i) in the toner base particles, particles having a circle-equivalent diameter of 3.00 ?m or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950, (ii) in the particles having a circle-equivalent diameter of 3.00 ?m or more in the toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and (iii) in the particles having a circle-equivalent diameter of 3.00 ?m or more in the toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less. Also disclosed is a full-color image forming method making use of the toner.Type: GrantFiled: September 9, 2004Date of Patent: October 30, 2007Assignee: Canon Kabushiki KaishaInventors: Kazuhiko Hayami, Tetsuya Ida, Nozomu Komatsu, Yasuhiro Ichikawa, Akira Hashimoto, Hirohide Tanikawa, Takakuni Kobori, Takayuki Itakura, Hiroyuki Fujikawa, Koh Ishigami, Nobuyoshi Sugahara
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Patent number: 7279262Abstract: A magnetic carrier composed of carrier particles is provided in which each carrier particle has a carrier core including magnetic fine particles and a binder resin with the carrier core surface being coated with a coat material containing a coat resin. In the magnetic carrier, Fatom/Catom and (Fatom/Catom)/(Fcalc/Ccalc) are respectively in specific ranges, wherein Fatom and Catom represent respectively a fluorine element abundance ratio and a carbon element abundance ratio at the magnetic carrier particle surface, and Fcalc and Ccalc represent respectively a fluorine element abundance ratio and a carbon element abundance ratio which are calculable from the molecular structure of the coat resin. In addition, a two-component developer is provoded including the magnetic carrier and a toner having a specific contact angle against water.Type: GrantFiled: November 16, 2004Date of Patent: October 9, 2007Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Fujikawa, Takayuki Itakura, Takakuni Kobori, Koh Ishigami, Nobuyoshi Sugahara, Yoshinobu Baba, Hirohide Tanikawa
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Publication number: 20070224531Abstract: The present invention provides a yellow toner which is excellent in transparency of an image formed on an OHP sheet, excellent in color reproducibility even when a light-pressure fixing unit is employed, excellent in coloring power and charge property, and is reduced in occurrence of filming. The present invention also provides a yellow toner having excellent durability and capable of contributing to the simplification or miniaturization of the constitution of an image forming apparatus. The yellow toner of the invention comprises a binder resin and a colorant, the binder resin contains at least a polyester unit, and the toner in the powder state has a lightness L* satisfying the relationship of L*>87 and has a chromaticity b* satisfying the relationship of 106<b*<120.Type: ApplicationFiled: May 24, 2007Publication date: September 27, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Tetsuya Ida, Yasuhiro Ichikawa, Wakashi Iida, Yojiro Hotta, Kazuhiko Hayami, Hirohide Tanikawa
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Publication number: 20070184372Abstract: A magenta toner is provided which contains at least a binder resin, a colorant, and a wax, in which a maximum heat-absorption peak temperature as measured using a differential scanning calorimeter, a reflectance at a predetermined wavelength when measured in a powder state by spectroscopic analysis, and lightness when measured in a powder form are in specific ranges. A full-color image is formed using the magenta toner as a pale magenta toner in combination with a deep magenta toner. According to the present invention, it becomes possible to form a vivid image which has reduced graininess and roughness from a low-density region to a high-density region, ensures a sufficient fixing temperature region, has a color reproduction range wider that the conventional one, and has high transparency on an OHP sheet.Type: ApplicationFiled: March 30, 2007Publication date: August 9, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Takayuki Itakura, Yuko Sato, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Hirohide Tanikawa
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Publication number: 20070122727Abstract: Provided a toner including at least: toner particles each containing at least a binder resin, a release agent, and a colorant; and an inorganic fine powder, in which: a degree of aggregation Y1 at a time of compression (200 kpa) of the toner satisfies a relationship of 15?Y1?35, and a degree of aggregation Y2 at a time of non-compression of the toner satisfies a relationship of 7?Y2?15; and a highest endothermic peak of the toner is present in a temperature range of 30 to 200° C. in an endothermic curve measured with a differential scanning calorimeter (DSC), and a peak temperature Tsc (° C.) of the highest endothermic peak satisfies a relationship of 60?Tsc?130.Type: ApplicationFiled: January 30, 2007Publication date: May 31, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Tetsuya Ida, Takeshi Ootsu, Koh Ishigami, Naoki Okamoto, Nozomu Komatsu, Noriyoshi Umeda, Yoshinobu Baba, Takayuki Itakura, Takeshi Naka, Hirohide Tanikawa
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Patent number: 7138213Abstract: The present invention provides a cyan toner including: one or plural heat-absorption peaks in a temperature range of 30 to 200° C. in a heat-absorption curve obtained by using a differential scanning calorimeter; a maximal value of a maximum heat-absorption peak temperature in the range of 65 to 150° C.; and a reflectance of 45 to 80% at a wavelength of 500 nm, a reflectance of 5 to 30% at a wavelength of 600 nm, and a brightness L* of 45 to 75, when measured in a powder form by spectroscopic analysis. The present invention thus provides a cyan toner capable of forming an image with reduced graininess and roughness from a low-density region to a high-density region and ensured a sufficient fixing temperature region, and a method for forming an image using the cyan toner.Type: GrantFiled: March 5, 2004Date of Patent: November 21, 2006Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Yoshinobu Baba, Yuko Sato, Nobuyoshi Sugahara, Kazuo Terauchi, Takaaki Kotaki, Hirohide Tanikawa
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Patent number: 7112395Abstract: To provide a color toner which is effective in mitigating contamination of a charging member, which is good at low temperature fixing in high-speed copying, and which is excellent in blocking resistance and electrification stability in continuous copying. Provided is a color toner containing at least a binder resin, a colorant, and a releasing agent, in which: (i) the binder resin contains at least a polyester unit; (ii) a weight average particle diameter of the color toner is greater than 6.5 ?m and equal to or less than 11 ?m; (iii) an average circularity A of particles in the color toner each having a circle-equivalent diameter of 3 ?m or more satisfies the relationship of 0.915?A?0.960; (iv) a permeability B (%) of the color toner in a 45 vol % aqueous solution of methanol satisfies the relationship of 10?B?70; and (v) an endothermic curve obtained through differential thermal analysis (DSC) measurement of the color toner has one or multiple endothermic peaks in the temperature range of 30 to 200° C.Type: GrantFiled: March 5, 2004Date of Patent: September 26, 2006Assignee: Canon Kabushiki KaishaInventors: Tetsuya Ida, Yasuhiro Ichikawa, Hirohide Tanikawa, Nozomu Komatsu
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Publication number: 20060008723Abstract: The present invention provides a toner improved in dispersibility of a colorant in the toner particles and excellent in the color reproducibility including color mixability and transparency. The toner is also excellent in the stability in long-term of the chargeability and capable of forming images maintaining high image quality. The present invention provides a toner for forming a full-color image which includes at least toner particles containing a binder resin, a colorant and a wax, and inorganic fine particles, wherein the binder resin comprises a resin having polyester units which is synthesized by use of an aromatic carboxylic acid titanium compound as a catalyst, and the inorganic fine particles comprise fine titanium oxide particles.Type: ApplicationFiled: September 14, 2005Publication date: January 12, 2006Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Nobuyoshi Sugahara, Takayuki Itakura, Naoki Okamoto, Koh Ishigami, Yoshinobu Baba, Hirohide Tanikawa