Patents by Inventor Koichi Tomiyama
Koichi Tomiyama 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: 6365314Abstract: A toner for developing electrostatic images. having a uniform composition and uniform performances over varying sizes of toner particles is constituted by (a) a binder resin, (b) a long-chain alkyl compound and (c) a specific azo-type iron complex. The long-chain alkyl compound is represented by the following formula (1), (2) or (3): CH3&Parenopenst;CH2&Parenclosest;xCH2OH (1), CH3&Parenopenst;CH2&Parenclosest;yCH2COOH (3), wherein x and y independently denote an average value in the range of 35-150.Type: GrantFiled: December 9, 1999Date of Patent: April 2, 2002Assignee: Canon Kabushiki KaishaInventors: Koichi Tomiyama, Takaaki Kohtaki, Manabu Ohno, Makoto Unno, Yushi Mikuriya, Nobuyuki Okubo, Tadashi Doujo, Shunji Suzuki
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Patent number: 6238834Abstract: A magnetic toner for developing an electrostatic image is comprised of magnetic toner particles containing at least a binder resin, a magnetic fine powder and a wax. The magnetic toner particles have a weight-average particle diameter of from 3.5 to 6.5 &mgr;m, and a dispersion prepared by dispersing 15 mg of the magnetic toner particles in 19 ml of an aqueous solution of ethyl alcohol and water in a volume ratio of 27:73 has an absorbance of from 0.2 to 0.7 at a wavelength of 600 nm. A process for producig such a magnetic toner is charcterized by, especially, the melt-kneading step carried out under the following conditions: 2.2×103≦E/&egr;≦2.Type: GrantFiled: May 28, 1998Date of Patent: May 29, 2001Assignee: Canon Kabushiki KaishaInventors: Osamu Tamura, Koichi Tomiyama, Shunji Suzuki, Yoshihiro Ogawa
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Patent number: 6187495Abstract: A yellow toner suitable for electrophotography is formed by dispersing a yellow colorant mixture in a binder resin.Type: GrantFiled: August 31, 1999Date of Patent: February 13, 2001Assignee: Canon Kabushiki KaishaInventors: Tatsuhiko Chiba, Kazuo Yoshinaga, Satoshi Yasuda, Hiroaki Kawakami, Ryoichi Fujita, Shinya Yachi, Koichi Tomiyama
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Patent number: 6090515Abstract: A toner for developing electrostatic images includes a binder resin, a specific long-chain alkyl compound and a specific azo iron complex. The long-chain alkyl compound contains a terminal --OH or --COOH group and from about 35 to 150 (--CH.sub.2 --) groups. The azo iron complex has a cation including 75-98 mol. % of ammonium ion and another ion which is hydrogen, sodium, potassium or mixtures thereof.Type: GrantFiled: May 23, 1997Date of Patent: July 18, 2000Assignee: Canon Kabushiki KaishaInventors: Koichi Tomiyama, Takaaki Kohtaki, Manabu Ohno, Makoto Unno, Yushi Mikuriya, Nobuyuki Okubo, Tadashi Doujo, Shunji Suzuki
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Patent number: 6060202Abstract: An electrophotographic toner including a blend of toner particles, and external additive particles, is provided with characteristic particle size distribution conditions, i.e., (i) a particle size distribution based on a Coulter counter measurement, including a weight-average particle size D4 of X .mu.m and Y % by number of particles having sizes of 2.00-3.17 .mu.m satisfying:-5X+35.ltoreq.Y.ltoreq.-25X+180 (1)3.5.ltoreq.X.ltoreq.6.5 (2), and(ii) a particle size distribution based on a flow particle image analyzer measurement, including A % by number of particles having circle-equivalent diameters of at least 1.00 .mu.m and below 1.03 .mu.m and B % by number of particles having circle-equivalent diameters of at least 2.00 .mu.m and below 2.06 .mu.m satisfying:B-A.ltoreq.0.30 (3).As a result, the toner is provided with a stable developing performance even in a long period of continuous image formation in a high temperature/high humidity environment.Type: GrantFiled: March 24, 1998Date of Patent: May 9, 2000Assignee: Canon Kabushiki KaishaInventors: Yoshihiro Ogawa, Koichi Tomiyama, Keita Nozawa, Shunji Suzuki
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Patent number: 6002895Abstract: A toner is comprised of a composition containing at least a polymer component and a charge control agent. The polymer component contains substantially no tetrahydrofuran (THF)-insoluble matter. The polymer component THF-soluble has a major peak and a minor peak in the specific molecular weight regions in gel permeation chromatography (GPC). The low molecular weight component and high molecular weight component of the polymer component, each of which shows the specific molecular weight region in GPC, have the specific acid values, respectively. The difference between the acid values is in the specific range.Type: GrantFiled: July 15, 1997Date of Patent: December 14, 1999Assignee: Canon Kabushiki KaishaInventors: Takashige Kasuya, Hiroyuki Suematsu, Koichi Tomiyama, Hiroshi Yusa, Takakuni Kobori, Masaichiro Katada
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Patent number: 5976752Abstract: An electrophotographic toner is composed of at least a binder resin, a colorant, and a wax. The binder resin (a) comprises a polyester resin, a vinyl resin and a hybrid resin component comprising a polyester unit and a vinyl polymer unit, (b) has a THF (tetrahydrofuran)-soluble content (W1) of 50-85 wt. % and a THF-insoluble content (W2) of 5-50 wt. %, an ethyl acetate-soluble content (W3) of 40-98 wt. % and an ethyl acetate-insoluble content (W4) of 2-60 wt. %, a chloroform-soluble content (W5) of 55-90 wt. % and a chloroform-insoluble content (W6) of 10-45 wt. %, respectively after 10 hours of Soxhlet extraction with respective solvents, giving a ratio W4/S6 of 1.1-4.0, and contains a THF-soluble content providing a GPC (gel permeation chromatography) chromatogram exhibiting a main peak in a molecular weight range of 4000-9000, including 35.0-65.0% (A1) of a component haing molecular weights in a range of 500 to below 1.times.10.sup.4, 25.0-45.0% (A2) of a component having molecular weights in a range of 1.Type: GrantFiled: August 18, 1998Date of Patent: November 2, 1999Assignee: Canon Kabushiki KaishaInventors: Satoshi Matsunaga, Koichi Tomiyama, Yuichi Mizoh, Keita Nozawa, Minekazu Endo, Tadashi Doujo, Yoshihiro Ogawa, Nene Shibayama
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Patent number: 5858593Abstract: Disclosed are a magnetic toner for developing an electrostatic latent image comprising magnetic toner particles containing a binder resin of 100 parts by weight and a magnetic substance of 20 to 150 parts by weight, and an apparatus unit and an image forming method for employing the magnetic toner. A frictional electrification property is such that the absolute value of the frictional electrification amount relative to an iron powder of 250 mesh-pass to 350 mesh-on is 25 to 40 mc/kg. Assuming that for particle distribution of the magnetic toner a weight-average particle diameter (D.sub.4) for the magnetic toner is X (.mu.m) and that a count % in a count distribution of magnetic toner particles that have a diameter of 3.17 .mu.m or smaller is Y (%), expressions (1) and (2) are satisfied:-5X+35.ltoreq.Y.ltoreq.-25X+180 (1)3.5.ltoreq.X.ltoreq.6.5 (2).Sphericity (.psi.) of particles is equal to or greater than 0.80 and a product (.sigma..sub.r .times.H.sub.c) of remanence ?.sigma..sub.r (Am.sup.Type: GrantFiled: July 29, 1997Date of Patent: January 12, 1999Assignee: Canon Kabushiki KaishaInventors: Osamu Tamura, Koichi Tomiyama, Nobuyuki Okubo, Shunji Suzuki, Yoshihiro Ogawa, Keita Nozawa
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Patent number: 5802428Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic latent image; a contact charging means for contact charging the member to be charged and a developing means for developing the latent image. The developing means includes a developer having a magnetic toner and fine powder treated with a silicone oil or varnish-treating agent, wherein the magnetic toner particles include a binder resin and contain from 10-70 wt. % of magnetic fine powder. An image forming method includes the steps of contact charging, latent image forming and developing with a developer having the binder resin, 10 to 70 wt. % magnetic fine powder and fine powder treated with a silicone oil or varnish-treating agent.Type: GrantFiled: April 18, 1995Date of Patent: September 1, 1998Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Hisayuki Ochi, Tetsuhito Kuwashima, Hiroyuki Suematsu, Eiichi Imai, Tsuyoshi Takiguchi, Koichi Tomiyama, Tsutomu Kukimoto, Hiroshi Yusa
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Patent number: 5750302Abstract: A magnetic toner for developing an electrostatic image has magnetic toner particles containing at least a binder resin and magnetic iron oxide particles. The magnetic iron oxide particles have been surface-treated with an aliphatic alcohol having carbon atoms of from 12 to 300 on the average. The magnetic toner has a weight average particle diameter of 13.5 .mu.m or smaller, and contains magnetic toner particles with particle diameters of 3.17 .mu.m or smaller in an amount not less than 1% by number as number-based percentage determined from number distribution.Type: GrantFiled: March 24, 1997Date of Patent: May 12, 1998Assignee: Canon Kabushiki KaishaInventors: Yoshihiro Ogawa, Koichi Tomiyama, Osamu Tamura, Nobuyuki Okubo, Shunji Suzuki
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Patent number: 5736288Abstract: A toner is comprised of a composition containing at least a polymer component and a charge control agent. The polymer component contains substantially no tetrahydrofuran (THF)-insoluble matter. The polymer component THF-soluble has a major peak and a minor peak in the specific molecular weight regions in gel permeation chromatography (GPC). The low molecular weight component and high molecular weight component of the polymer component, each of which shows the specific molecular weight region in GPC, have the specific acid values, respectively. The difference between the acid values is in the specific range.Type: GrantFiled: May 15, 1995Date of Patent: April 7, 1998Assignee: Canon Kabushiki KaishaInventors: Takashige Kasuya, Hiroyuki Suematsu, Koichi Tomiyama, Hiroshi Yusa, Takakuni Kobori, Masaichiro Katada
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Patent number: 5663026Abstract: A magnetic toner is formed from a binder resin and silicon-containing magnetic iron oxide particles. The magnetic toner has a weight-average particle size of at most 13.5 .mu.m, and the magnetic toner has a particle size distribution such that magnetic toner particles having a particle size of at least 12.7 .mu.m are contained in an amount of at most 50 wt. %. The magnetic iron oxide particles have a silicon content of 0.4-2.0 wt. % based on iron, and the magnetic iron oxide particles have an Fe/Si atomic ratio of 1.2-4.0 at the utmost surfaces thereof. Because of the use of such magnetic iron oxide particles having a specifically controlled overall and surface Si contents, the magnetic toner can show stable performances even after standing in a high humidity environment.Type: GrantFiled: March 20, 1996Date of Patent: September 2, 1997Assignee: Canon Kabushiki KaishaInventors: Takashige Kasuya, Hiroyuki Suematsu, Koichi Tomiyama, Hiroshi Yusa, Takakuni Kobori, Masaichiro Katada
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Patent number: 5534981Abstract: An image forming apparatus includes a member to be charged for carrying an electrostatic image, a contact-charging means for charging the member to be charged in contact with the member to be charged, and a developing means for developing the electrostatic image carried on the member to be charged. The developing means includes a developer for developing the electrostatic image comprising a toner and hydrophobic inorganic fine powder. The hydrophobic fine powder has a hydrophobicity of 60% or higher and the toner has a volume average particle size of 4-8 microns. The hydrophobic inorganic fine powder not only improves the fluidity of the developer and adjusts the chargeability of the developer but also prevents difficulties due to interaction between the member to be charged and the contact charging means in the presence of residual developer, such as damages of the member to be charged and toner-sticking onto the member to be charged.Type: GrantFiled: August 19, 1993Date of Patent: July 9, 1996Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Hisayuki Ochi, Tetsuhito Kuwashima, Hiroyuki Suematsu, Eiichi Imai, Tsuyoshi Takiguchi, Koichi Tomiyama, Tsutomu Kukimoto, Hiroshi Yusa
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Patent number: 5510223Abstract: An image forming method, including the steps of: developing an electrostatic image formed on an electrostatic image-bearing member with a developer to form thereon thereon a developed image, the developer containing 100 wt. parts of a toner and 0.05 to 3 wt. parts of fine powder treated with a silicone oil or silicone varnish; and transferring the developed image on the electrostatic image-bearing member to a transfer material while causing a transfer device, such as a roller or belt to contact the electrostatic image-bearing member by the medium of the transfer material under a line pressure of 3 g/cm or higher.Type: GrantFiled: December 30, 1994Date of Patent: April 23, 1996Assignee: Canon Kabushiki KaishaInventors: Tsutomu Kukimoto, Hiroshi Yusa, Koichi Tomiyama, Tsuyoshi Takiguchi, Eiichi Imai, Tetsuya Kuribayashi, Hisayuki Ochi, Hiroyuki Suematsu
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Patent number: 5464722Abstract: A toner for developing electrostatic images is produced through a process including the steps of: pre-mixing binder resin particles carrying or containing inorganic fine powder to prepare a premix; melt-kneading the premix to obtain a kneaded product; cooling the kneaded product to obtain a colored resinous solid; pulverizing the colored resinous solid to obtain a pulverized product; and classifying the pulverized product to obtain toner particles. The inclusion of the resin particles carrying or containing inorganic fine powder improves the performance of the pre-mixing to provide an improved dispersion of toner materials within the product toner particles. A fine powder fraction from the classifying step can also be recycled to the premixing step. The resin particles can be toner particles per se. The inorganic fine powder may preferably be silica fine powder treated with silicone oil.Type: GrantFiled: January 3, 1994Date of Patent: November 7, 1995Assignee: Canon Kabushiki KaishaInventors: Koichi Tomiyama, Hiroshi Yusa, Takakuni Kobori
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Patent number: 5447815Abstract: A developer for developing an electrostatic image, comprising a toner and treated fine powder which has been treated with silicone oil or silicone varnish, wherein the treated fine powder has a specific surface area which is 0.4 to 0.8 time as large as the specific surface area of untreated fine powder.Type: GrantFiled: June 3, 1993Date of Patent: September 5, 1995Assignee: Canon Kabushiki KaishaInventors: Masayoshi Kato, Koichi Tomiyama, Hiroshi Yusa
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Patent number: 5424810Abstract: A magnetic toner for electrophotography is composed from a binder resin and a silicon-containing magnetic iron oxide. The magnetic toner has a weigh-average particle size o at most 13.5 .mu.m and has a particle size distribution such that it contains o more than 50 wt, % of magnetic toner particles having a particle size of at least 12.7 .mu.m. The magnetic toner is able to show high developing performances because of richness in fine particles and is also provided with an improved environmental stability because the magnetic iron oxide used therein contains 0.5-4 wt, % silicon (based on total iron content) and has a specific silicon distribution such that the magnetic iron oxide has a total silicon content (A), a silicon content (B) dissolved together with the magnetic iron oxide when the magnetic iron oxide is dissolved up to 20 wt, % dissolution of iron, and a superficial silicon content (C), satisfying relations of B/A=44-84% and C/A=10-55%.Type: GrantFiled: September 10, 1992Date of Patent: June 13, 1995Assignee: Canon Kabushiki KaishaInventors: Koichi Tomiyama, Hiroyuki Suematsu, Masayoshi Kato, Hiroshi Yusa, Takakuni Kobori
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Patent number: 5422707Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. The toner has a glass transition temperature (Tg) of 65.degree. C. or lower. The binder resin comprises a styrene-acrylic copolymer formed from at least a styrenic monomer and a mixture of two or more acrylic monomers. The binder resin contains 10% by weight or more of THF insolubles. The amount of the styrenic monomer remaining in the toner is 0.005 part or less by weight based on 100 parts by weight of the binder resin component in the toner (50 ppm), and the amount of the acrylic monomers remaining in said toner is 0.001 part by weight based on 100 parts by weight or less of the binder resin component in the toner (10 ppm). At least one component of the mixture of acrylic monomers has a Q-value of 0.5 to less than 1.0 and the other has a Q-value of 0.3 to less than 0.5.This toner is excellent in the anti-off-set property to a fixing roller surface, good in fixability, giving high image density and little odor.Type: GrantFiled: September 13, 1994Date of Patent: June 6, 1995Assignee: Canon Kabushiki KaishaInventors: Tsuyoshi Takiguchi, Tsutomu Kukimoto, Koichi Tomiyama, Hiroshi Yusa, Tetsuhito Kuwashima
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Patent number: 5392103Abstract: An image forming method, including the steps of: developing an electrostatic image formed on an electrostatic image-bearing member with a developer to form thereon thereon a developed image, the developer containing 100 wt. parts of a toner and 0.05 to 3 wt. parts of fine powder treated with a silicone oil or silicone varnish; and transferring the developed image on the electrostatic image-bearing member to a transfer material while causing a transfer device, such as a roller or belt to contact the electrostatic image-bearing member by the medium of the transfer material under a line pressure of 3 g/cm or higher.Type: GrantFiled: November 4, 1993Date of Patent: February 21, 1995Assignee: Canon Kabushiki KaishaInventors: Tsutomu Kukimoto, Hiroshi Yusa, Koichi Tomiyama, Tsuyoshi Takiguchi, Eiichi Imai, Tetsuya Kuribayashi, Hisayuki Ochi, Hiroyuki Suematsu
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Patent number: 5338638Abstract: A toner for developing an electrostatic image is provided as a pulverized mixture including a binder resin and a colorant. The binder resin is characterized by a molecular weight distribution on a GPC chromatogram of its tetrahydrofuran (THF)-soluble resin content including at least 15% and below 35% of a resin component in a molecular weight region of at most 5000 and at least 3 wt. % of a resin component in a molecular weight region of at least 5.times.10.sup.6 and showing a main peak in a molecular weight region of 5000 to 10.sup.5. The binder resin also has an acid value of 2-100 mg KOH/g. The THF-soluble resin component in the molecular weight region of at least 5.times.10.sup.6 is enriched during a melt-kneading step during the toner production.Type: GrantFiled: November 26, 1991Date of Patent: August 16, 1994Assignee: Canon Kabushiki KaishaInventors: Kiyoko Tsuchiya, Koichi Tomiyama, Masayoshi Kato, Tsutomu Kukimoto, Hiroshi Yusa