Patents by Inventor Yasuhiro Ichikawa
Yasuhiro Ichikawa 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).
-
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
-
Patent number: 7300733Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 ?m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 ?m or more is 0.915 to 0.960; loss tangent tan? (103 to 104 Hz) of the toner is represented by the following expression: tan? (103 to 104 Hz)?0.0060 where the loss tangent tan? is represented by ??/?? where ?? denotes dielectric loss factor and ?? denotes dielectric constant, and tan? (103 to 104 Hz) denotes the loss tangent in a frequency range of 103 to 104 Hz; and a ratio of tan? (105 Hz) to tan? (5×104 Hz) is represented by the following expression: 1.05?tan? (105 Hz)/tan? (5×104 Hz)?1.Type: GrantFiled: September 14, 2005Date of Patent: November 27, 2007Assignee: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Takaaki Kohtaki, Yasuhiro Ichikawa, Tetsuya Ida, Kazuhiko Hayami, Nozomu Komatsu
-
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
-
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
-
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
-
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
-
Publication number: 20060113404Abstract: In a cleaning device for a vehicle lamp for jetting a cleaning liquid to a front surface of a vehicle lamp by a piston and a cylinder, the piston is urged in the direction in which it is retracted into the cylinder by a tensile spring arranged between the piston and the cylinder and passing through the inside of the piston.Type: ApplicationFiled: November 28, 2005Publication date: June 1, 2006Inventors: Masaaki Sato, Yasuhiro Ichikawa, Toshiyuki Tsukamoto, Masaru Sakai
-
Patent number: 7022449Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 ?m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 ?m or more is 0.915 to 0.960; loss tangent tan ? (103 to 104 Hz) of the toner is represented by the following expression: tan ?(103 to 104 Hz)?0.0060 where the loss tangent tan ? is represented by ??/?? where ?? denotes dielectric loss factor and ?? denotes dielectric constant, and tan ? (103 to 104 Hz) denotes the loss tangent in a frequency range of 103 to 104 Hz; and a ratio of tan ? (105 Hz) to tan ? (5×104 Hz) is represented by the following expression: 1.05?tan ?(105 Hz)/tan ?(5×104 Hz)?1.Type: GrantFiled: July 30, 2003Date of Patent: April 4, 2006Assignee: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Takaaki Kohtaki, Yasuhiro Ichikawa, Tetsuya Ida, Kazuhiko Hayami, Nozomu Komatsu
-
Publication number: 20060014095Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 ?m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 ?m or more is 0.915 to 0.960; loss tangent tan ? (103 to 104 Hz) of the toner is represented by the following expression: tan ? (103 to 104 Hz)?0.0060 where the loss tangent tan ? is represented by ??/?? where ?? denotes dielectric loss factor and ?? denotes dielectric constant, and tan ? (103 to 104 Hz) denotes the loss tangent in a frequency range of 103 to 104 Hz; and a ratio of tan ? (105 Hz) to tan ? (5×104 Hz) is represented by the following expression: 1.05?tan ? (105 Hz)/tan ? (5×104 Hz)?1.Type: ApplicationFiled: September 14, 2005Publication date: January 19, 2006Applicant: Canon Kabushiki KaishaInventors: Nobuyoshi Sugahara, Takaaki Kohtaki, Yasuhiro Ichikawa, Tetsuya Ida, Kazuhiko Hayami, Nozomu Komatsu
-
Publication number: 20050106488Abstract: 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: November 4, 2004Publication date: May 19, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Tetsuya Ida, Yasuhiro Ichikawa, Wakashi Iida, Yojiro Hotta, Kazuhiko Hayami, Hirohide Tanikawa
-
Publication number: 20050100808Abstract: 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: November 4, 2004Publication date: May 12, 2005Applicant: CANON KABUSHIKI KAISHAInventors: Akira Hashimoto, Yojiro Hotta, Wakashi Iida, Kazuhiko Hayami, Yasuhiro Ichikawa, Hirohide Tanikawa
-
Publication number: 20050079429Abstract: 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: ApplicationFiled: September 9, 2004Publication date: April 14, 2005Applicant: 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
-
Publication number: 20040175642Abstract: 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 &mgr;m and equal to or less than 11 &mgr;m; (iii) an average circularity A of particles in the color toner each having a circle-equivalent diameter of 3 &mgr;m or more satisfies the relationship of 0.915≦A≦0.Type: ApplicationFiled: March 5, 2004Publication date: September 9, 2004Inventors: Tetsuya Ida, Yasuhiro Ichikawa, Hirohide Tanikawa, Nozomu Komatsu
-
Publication number: 20040161688Abstract: 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: ApplicationFiled: January 9, 2004Publication date: August 19, 2004Inventors: Takayuki Itakura, Takaaki Kotaki, Yasuhiro Ichikawa, Takaaki Kaya, Wakashi Iida, Hiroyuki Fujikawa, Kazuhiko Hayami, Nobuyoshi Sugahara, Yojiro Hotta
-
Publication number: 20040058264Abstract: To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 &mgr;m; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 &mgr;m or more is 0.915 to 0.Type: ApplicationFiled: July 30, 2003Publication date: March 25, 2004Inventors: Nobuyoshi Sugahara, Takaaki Kohtaki, Yasuhiro Ichikawa, Tetsuya Ida, Kazuhiko Hayami, Nozomu Komatsu
-
Patent number: 6664016Abstract: A magenta toner having a storage elastic modulus at 80° C., G′80, from 1×106 dN/m2 to 1×108 dN/m2 and a storage elastic modulus at 120° C. to 180° C., G′120-180, from 2×103 dN/m2 to 1×106 dN/m2, and containing a compound represented by Formulas (1) and (2) and a compound represented by Formula (3): wherein RD2 represents H or OCH3, RD4 represents H or CONH2, RD5 represents H, SO2N(C2H5)2, CONHC6H5, CONH2 or CONHC6H4-(p)CONH2, RK2 represents H, OCH3, CH3 or OC2H5, RK4 represents H, OCH3 or Cl, and RK5 represents H, OCH3, Cl or NO2; wherein RD2 represents H or SO3—, RD4 represents H, Cl or CH3, RD5 represents H, Cl, CH3, C2H5, or SO3—, and M represents Ba, Ca, Sr, Mn or Mg; provided that one of RD2 and RD5 is SO3. wherein RD1 and RD2 each represent H or CH3.Type: GrantFiled: July 10, 2001Date of Patent: December 16, 2003Assignee: Canon Kabushiki KaishaInventors: Makoto Kanbayashi, Takaaki Kotaki, Katsumi Kondo, Yasuhiro Ichikawa, Takaaki Kaya, Wakashi Iida, Takayuki Itakura
-
Publication number: 20020037466Abstract: A magenta toner containing at least a binder resin and a colorant; the magenta toner having a storage elastic modulus at a temperature of 80° C., G′80, in the range of from 1×106 dN/m2 to 1×108 dN/m2 and a storage elastic modulus at a temperature of from 120° C. to 180° C., G′120-180, in the range of from 2×103 dN/m2 to 1×106 dN/m2, and containing at least a compound selected from the group consisting of compounds represented by the following Formulas (1) and (2) and a compound represented by the following Formula (3).Type: ApplicationFiled: July 10, 2001Publication date: March 28, 2002Inventors: Makoto Kanbayashi, Takaaki Kotaki, Katsumi Kondo, Yasuhiro Ichikawa, Takaaki Kaya, Wakashi Iida, Takayuki Itakura
-
Patent number: 6187490Abstract: A two-component developer suitable for electrophotography is formed of a toner and a resin-coated carrier. The resin-coated carrier is formed of carrier core particles and 0.01-2.0 wt. % based on the carrier core particles of a resin coating layer coating the carrier core particles. The resin-coated carrier has an average particle size of 25-55 &mgr;m and the carrier core particles comprise a ferrite component represented by formula (I) below: (Fe2O3)a(MnO)b(MgO)c(A)d (I), wherein A represents a mixture of SrO, CaO and Al2O3, and a, b, c and d are numbers representing mol fractions of associated components and satisfying: 0.4<a<0.6, 0.35<b<0.45, 0.07<c<0.12, 0.005<d<0.015, and a+b+c+d≦1. Because of the specific composition, the carrier core particles are provided with a smooth surface, which is reflected into a surface smoothness of the resin-coated carrier even after coated with a thin resin coating layer.Type: GrantFiled: March 15, 2000Date of Patent: February 13, 2001Assignee: Canon Kabushiki KaishaInventors: Masaaki Taya, Takaaki Kohtaki, Yasuhiro Ichikawa
-
Patent number: 6146801Abstract: A resin-coated carrier for two component type developers, with carrier particles having a carrier core material and a coat layer which covers the surface of the carrier core material. The resin-coated carrier has a 50% particle diameter C (D.sub.50) from 25 .mu.m to 70 .mu.m, contains carrier particles smaller than 22 .mu.m in particle diameter in an amount from 0.1% by number to 20% by number and contains carrier particles of 62 .mu.m or larger in particle diameter in an amount from 2% by number to 35% by number. The carrier core material has a BET specific surface area SW1 where the coat layer has been removed and the resin-coated carrier has a BET specific surface area SW2. The SW1 and SW2 satisfy the following expression (I), and the resin-coated carrier satisfies a shape factor SF-1 of the following expression (II) and a shape factor SF-2 of the following expression (III):80.ltoreq.SW1-SW2.ltoreq.650(cm.sup.2 /g) (I)110.ltoreq.SF-1.ltoreq.160 (II)105.ltoreq.SF-2.ltoreq.Type: GrantFiled: September 29, 1999Date of Patent: November 14, 2000Assignee: Canon Kabushiki KaishaInventors: Yasuhiro Ichikawa, Tetsuya Ida
-
Patent number: 5733702Abstract: An image forming method is conducted by forming a toner image on a latent image bearing member containing an organic photoconductive material. The latent image bearing member includes a photosensitive layer containing an organic photoconductive material and a protective layer which contains fluorine-containing resin particles in an amount from 5% by weight to 40% by weight. The toner contains toner particles and external additives. The external additives include titanium oxide particles having a weight average particle diameter from 0.01 .mu.m to 0.2 .mu.m having been subjected to hydrophobic treatment, organic resin particles having a weight average particle diameter from 0.02 .mu.m to 0.5 .mu.m, and inorganic compound particles having a weight average particle diameter from 0.5 .mu.m to 2.5 m.The inorganic compound particles may be specific titanates, oxides or carbonate.Type: GrantFiled: April 5, 1995Date of Patent: March 31, 1998Assignee: Canon Kabushiki KaishaInventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Tsuyoshi Takiguchi, Yasuhiro Ichikawa