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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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: 7297455Abstract: A toner is composed primarily of toner particles containing at least a binder resin, a colorant and a wax, and inorganic fine particles. The binder resin is one which has at least a polyester unit and is synthesized by using as a catalyst one or more compounds selected from titanium chelate compounds each having a specific structure and hydrates of the titanium chelate compounds. The toner has superior fixing performance and high-temperature anti-offset properties and is superior in charge stability even when used for a long time.Type: GrantFiled: July 28, 2004Date of Patent: November 20, 2007Assignee: Canon Kabushiki KaishaInventors: Hiroyuki Fujikawa, Yuko Sato, Nobuyoshi Sugahara, Takayuki Itakura
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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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Patent number: 7272348Abstract: A developing method using a developing device including at least: a first developer bearing member arranged to be opposed to an image bearing member; and a second developer bearing member arranged on a downstream side of a rotation direction of the image bearing member with respect to the first developer bearing member, the developing method including developing a latent image formed on the image bearing member with a developer, in which: the developer is a two-component developer having toner and a magnetic carrier; and the developer has a degree of compression C in the range of 20 to 32% and a shearing stress obtained by shearing stress measurement under a consolidation load of 4.0×10?4 N/mm2 in the range of 0.5×10?4 to 2.5×10?4 N/mm2.Type: GrantFiled: April 26, 2005Date of Patent: September 18, 2007Assignee: Canon Kabushiki KaishaInventors: Naoki Okamoto, Hiroyuki Fujikawa, Koh Ishigami, Nobuyoshi Sugahara, Yoshinobu Baba, Takayuki Itakura
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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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Patent number: 7229727Abstract: A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the. wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.Type: GrantFiled: November 23, 2004Date of Patent: June 12, 2007Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Takaaki Kotaki, Takaaki Kaya, Kazuhiko Hayami, Nozomu Komatsu
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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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Publication number: 20070031747Abstract: A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.Type: ApplicationFiled: September 21, 2006Publication date: February 8, 2007Applicant: CANON KABUSHIKI KAISHAInventors: Takayuki Itakura, Takaaki Kotaki, Takaaki Kaya, Kazuhiko Hayami, Nozomu Komatsu
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Patent number: 7147980Abstract: A toner having toner particles each comprising at least a binder resin, a wax, and a colorant is used in an image forming apparatus which has a fixing means comprising a belt-shaped heating member and a pressurizing member. The binder resin contains a resin formed by a reaction between an epoxy group of a vinyl resin (A) having the epoxy group and a carboxyl group of a resin (B) having at least a polyester unit and the carboxyl group. The toner has a storage elastic modulus at a temperature of 80° C. (G? 80) in the range of 1×105 to 1×108 Pa and has a storage elastic modulus at a temperature of 160° C. (G? 160) in the range of 1×101 to 1×104 Pa.Type: GrantFiled: January 9, 2004Date of Patent: December 12, 2006Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Takaaki Kotaki, Yasuhiro Ichikawa, Takaaki Kaya, Wakashi Iida, Hiroyuki Fujikawa, Kazuhiko Hayami, Nobuyoshi Sugahara, Yojiro Hotta
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Patent number: 7144668Abstract: The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0–6.5 ?m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 ?m or more of 0.920–0.945; has a BET specific surface area of 2.1–3.5 m2/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30–80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15–80 ?m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.Type: GrantFiled: March 5, 2004Date of Patent: December 5, 2006Assignee: Canon Kabushiki KaishaInventors: Yoshinobu Baba, Yuko Sato, Ryoichi Fujita, Takaaki Kotaki, Nobuyoshi Sugahara, Kazuo Terauchi, Takayuki Itakura
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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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Publication number: 20060251451Abstract: To provide a fixing method and a fixing device with each of which an image which has high gloss that is uniform irrespective of a toner mounting amount on a recording medium can be obtained at a relatively high recording medium conveying speed.Type: ApplicationFiled: April 26, 2005Publication date: November 9, 2006Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Naoki Okamoto, Yoshinobu Baba, Takayuki Itakura
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Patent number: 7115349Abstract: Provided is toner which is excellent in developing property, transferring property, and fixing property, hardly affected by its surrounding, and has good endurance. The toner has a peak temperature of maximum endothermic peak in the range of 60 to 100° C. in an endothermic curve of differential scanning calorimetry (DSC) measurement; silica particles in the toner contain a titanium element; and the silica particles satisfy the following expressions. 0.7?(Ia1/Ib1)?2.0 0.7?(Ia2/Ib2)?2.0 where Ia1 represents a maximum intensity in the case of 2?=25.3 deg, Ib1 represents a mean intensity in the cases of 2?=25.3 deg+2.0 deg. and of 2?=25.3 deg.?2.0 deg., Ia2 represents a maximum intensity in the case of 2?=27.5 deg and Ib2 represents a mean intensity in the cases of 2?=27.5. deg+2.0 deg. and of 2?=27.5 deg.?2.0 deg.Type: GrantFiled: November 28, 2003Date of Patent: October 3, 2006Assignee: Canon Kabushiki KaishaInventors: Wakashi Iida, Kazuhiko Hayami, Takayuki Itakura, Yojiro Hotta
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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
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Publication number: 20050244737Abstract: An image forming method and an image forming apparatus are disclosed in which an electrostatic latent image is formed on a photosensitive member surface by using a two-component developer including a toner and carrier. The photosensitive member surface has a specific modulus of elastic deformation and includes a charge transport layer with a specific thickness. The toner has a specific weight-average particle diameter. The carrier has a specific volume-average particle diameter and a specific circularity, and contains 20% by number or less of particles having a value of “average circularity?2 ?” where ? is standard deviation of carrier circularity.Type: ApplicationFiled: April 26, 2005Publication date: November 3, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Yoshinobu Baba, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Koh Ishigami, Naoki Okamoto, Takayuki Itakura
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Publication number: 20050238988Abstract: In an image forming method having primarily transferring step for transferring to an intermediate transfer member a toner image formed on a photosensitive member, secondarily transferring step for transferring to a transfer material the toner image held on the intermediate transfer member, and, after the secondary transferring step, cleaning step for removing the toner remaining on the intermediate transfer member by bringing a cleaning means into contact with the intermediate transfer member, the cleaning means is a fur brush or a charging roller, and the intermediate transfer member has a specific maximum displacement quantity (Sb) and has a specific elastic deformation percentage (Eb) (%); a toner which forms the toner image has a specific average circularity, has a specific maximum displacement quantity (St), and has a specific elastic deformation percentage (Et) (%); and the elastic deformation percentage of the intermediate transfer member and the elastic deformation percentage of the toner satisfy theType: ApplicationFiled: April 18, 2005Publication date: October 27, 2005Applicant: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Hiroyuki Fujikawa, Koh Ishigami, Naoki Okamoto, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20050238392Abstract: The present invention relates to a developing method using a developing device including at least: a first developer bearing member arranged to be opposed to an image bearing member; and a second developer bearing member arranged on a downstream side of a rotation direction of the image bearing member with respect to the first developer bearing member, the developing method including developing a latent image formed on the image bearing member with a developer, in which: the developer is a two-component developer having toner and a magnetic carrier; and the developer has a degree of compression C in the range of 20 to 32% and a shearing stress obtained by shearing stress measurement under a consolidation load of 4.0×10?4 N/mm2 in the range of 0.5×10?4 to 2.5×10?4 N/mm2.Type: ApplicationFiled: April 26, 2005Publication date: October 27, 2005Applicant: Canon Kabushiki KaishaInventors: Naoki Okamoto, Hiroyuki Fujikawa, Koh Ishigami, Nobuyoshi Sugahara, Yoshinobu Baba, Takayuki Itakura
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Patent number: 6929894Abstract: A toner is disclosed which is composed of toner particles containing at least a binder resin, a colorant and a wax, and an external additive. The wax has, in its DSC endothermic curve, a maximum endothermic peak at 55° C. to 80° C. within the temperature range from 30° C. to 160° C., the maximum endothermic peak having a half width of from 2° C. to 7° C., and the binder resin is composed chiefly of a polyester resin. The toner has a dynamic elastic modulus from 5×102 to 1×105 dN/m2 at 140° C., and its ratio to a dynamic elastic modulus at 170° C. is from 0.05 to 50, and the toner contains 10 to 20% by weight of THF-insoluble matter A of a binder resin component after 8 hours from the start of extraction and 1 to 10% by weight of THF-insoluble matter B of the binder resin component after 24 hours from the start of extraction, the ratio of A to B, B/A, being from 0.1 to 0.8. Also disclosed is a fixing method making use of this toner.Type: GrantFiled: July 10, 2002Date of Patent: August 16, 2005Assignee: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Masaaki Taya, Junko Yoshikawa, Takayuki Itakura, Yojiro Hotta
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Patent number: 6905808Abstract: A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.Type: GrantFiled: January 17, 2003Date of Patent: June 14, 2005Assignee: Canon Kabushiki KaishaInventors: Takayuki Itakura, Takaaki Kotaki, Takaaki Kaya, Kazuhiko Hayami, Nozomu Komatsu