Patents by Inventor Yuka Ishihara
Yuka Ishihara 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: 20060046173Abstract: An electrophotographic toner contains at least a binder resin and a colorant, and log10{[Cu]/[C]} satisfies the following equation (1): ?5.0?log10{[Cu]/[C]}??3.5 ??(1) in which, [C] represents a carbon content (%) and [Cu] represents a copper content (%), measured with fluorescent X-ray. An electrophotographic developer containing the toner, a method for producing the toner, and a method for forming an image by using the toner are also provided.Type: ApplicationFiled: March 15, 2005Publication date: March 2, 2006Applicant: FUJI XEROX CO., LTD.Inventors: Sueko Sakai, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Teruo Sakai
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Publication number: 20050208414Abstract: An electrophotographic toner having a core-shell structure including a crystalline resin in its core region or a sea-island structure including a crystalline resin in its island region, wherein the toner has 1) a resistance of 5.0×1012 ?·cm or higher, 2) a dynamic viscosity coefficient of 3×103 Pa·s or higher at a temperature which is 50° C. higher than a melting point of the crystalline resin, and 3) a dynamic viscosity coefficient of 1×105 Pa·s or lower at a temperature which is 10° C. higher than the melting point of the crystalline resin.Type: ApplicationFiled: October 14, 2004Publication date: September 22, 2005Applicant: FUJI XEROX CO., LTD.Inventors: Masaki Nakamura, Takashi Imai, Katsumi Daimon, Yuka Ishihara, Hirokazu Yamada, Hirokazu Hamano, Norihito Fukushima, Yasuhiro Arima
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Patent number: 6942951Abstract: The present invention provides an image forming method for efficiently thermoelectrically transferring and fixing a toner image formed on an electrostatic latent image carrier without scattering of the toner. The image forming method comprises the steps of charging a surface of an electrostatic latent image carrier; exposing the charged surface of the electrostatic latent image carrier to a light beam using optical data corresponding to image data to form a latent image; developing the latent image formed on the surface of the electrostatic latent image carrier with a developer for electrophotography containing a toner for electrophotography to form a toner image; and thermoelectrically transferring the toner image formed on the surface of said electrostatic latent image carrier onto a surface of a recording medium and simultaneously fixing thereon. The toner for electrophotography is comprised of a crystalline polyester resin, the surface temperature of a fixing unit therein is higher by 10° C.Type: GrantFiled: November 8, 2002Date of Patent: September 13, 2005Assignee: Fuji Xerox Co., Ltd.Inventors: Katsumi Daimon, Takashi Imai, Manabu Serizawa, Hirokazu Hamano, Norihito Fukushima, Yuka Ishihara
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Patent number: 6895205Abstract: An image fixing apparatus and an image forming method capable of favorably fixing a toner containing a crystalline resin are provided. The image forming apparatus passes a transfer medium having unfixed images formed of the toner containing a crystalline resin between a heating member and a pressurizing member, thereby fixing the unfixed images, using a cooling unit that controls a surface temperature of the pressurizing member in which the surface temperature is controlled to a melting point of the crystalline resin +30° C. or lower.Type: GrantFiled: June 17, 2003Date of Patent: May 17, 2005Assignee: Fuji Xerox Co., Ltd.Inventors: Masaki Nakamura, Toshimizu Ozawa, Yoshinari Ueno, Norihito Fukushima, Hirokazu Hamano, Yuka Ishihara
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Patent number: 6895206Abstract: An image fixing method capable of favorably fixing a toner containing a crystalline resin is provided. A transfer medium having unfixed images formed of a color toner containing a binder resin that contains a crystalline resin and a colorant is passed between a heating member heated by way of an external heating unit and a pressurizing member, thereby fixing the unfixed images.Type: GrantFiled: June 17, 2003Date of Patent: May 17, 2005Assignee: Fuji Xerox Company, LimitedInventors: Masaki Nakamura, Toshimizu Ozawa, Norihito Fukushima, Hirokazu Hamano, Yuka Ishihara, Manabu Serizawa, Katsumi Daimon
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Patent number: 6864029Abstract: The present invention uses a crystalline resin as a binding resin and provides a toner insuring excellent storability of a resulting image, a method of manufacturing the toner, an electrostatically charged image developer containing the toner, and an image forming method. In the electrophotographic toner containing toner mother particles comprising at least a binding resin and a colorant, a main component of said binding resin comprises a crystalline resin with a melting point in the range from 50 to 120° C. and an average volume particle size in the range from 3.0 to 7.5 ?m, while an average value of the BET specific areas of said toner mother particles is in the range from 0.6 to 3.0 m2/g. The electrophotographic toner manufacturing method comprises the steps of coalescing or associating the binding resin particles with colorant particles, and cooling the aggregated particles at the rate of at least 1° C.Type: GrantFiled: December 2, 2002Date of Patent: March 8, 2005Assignee: Fuji Xerox Co., Ltd.Inventors: Hirokazu Hamano, Manabu Serizawa, Katsumi Daimon, Yuka Ishihara, Norihito Fukushima, Takashi Imai
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Publication number: 20040037596Abstract: An image fixing method capable of favorably fixing a toner containing a crystalline resin is provided. A transfer medium having unfixed images formed of a color toner containing a binder resin that contains a crystalline resin and a colorant is passed between a heating member heated by way of an external heating unit and a pressurizing member, thereby fixing the unfixed images.Type: ApplicationFiled: June 17, 2003Publication date: February 26, 2004Applicant: Fuji Xerox Co., Ltd.Inventors: Masaki Nakamura, Toshimizu Ozawa, Norihito Fukushima, Hirokazu Hamano, Yuka Ishihara, Manabu Serizawa, Katsumi Daimon
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Publication number: 20040022562Abstract: An image fixing apparatus and an image forming method capable of favorably fixing a toner containing a crystalline resin are provided. The image forming apparatus passes a transfer medium having unfixed images formed of the toner containing a crystalline resin between a heating member and a pressurizing member, thereby fixing the unfixed images, using a cooling unit that controls a surface temperature of the pressurizing member in which the surface temperature is controlled to a melting point of the crystalline resin +30° C. or lower.Type: ApplicationFiled: June 17, 2003Publication date: February 5, 2004Applicant: FUJI XEROX CO., LTD.Inventors: Masaki Nakamura, Toshimizu Ozawa, Yoshinari Ueno, Norihito Fukushima, Hirokazu Hamano, Yuka Ishihara
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Patent number: 6607864Abstract: An image forming method makes the warming-up time short, enables the formation of high-quality images even when fixing is performed continuously at high speed, and restrains degradations of the image quality, such as non-uniformity of gloss and non-uniformity of coloration even under high-temperature and high-humidity conditions. The method uses a toner that is wide in fixing range and is especially excellent in low-temperature fixing property. The method contains a process of melting and thereby fixing a toner image formed by unfixed toner, by heating a heating member that is in contact with the toner image. The surface of the heating member or its vicinity that is in contact with the toner image generates heat, and the toner contains at least a colorant and a binder resin having a crystalline resin with a number average molecular weight of 1500 or more as the main component.Type: GrantFiled: December 14, 2001Date of Patent: August 19, 2003Assignee: Fuji Xerox Co., Ltd.Inventors: Manabu Serizawa, Katsumi Daimon, Hirokazu Hamano, Yuka Ishihara, Norihito Fukushima, Takashi Imai
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Publication number: 20030104296Abstract: The present invention uses a crystalline resin as a binding resin and provides a toner insuring excellent storability of a resulting image, a method of manufacturing the toner, an electrostatically charged image developer containing the toner, and an image forming method. In the electrophotographic toner containing toner mother particles comprising at least a binding resin and a colorant, a main component of said binding resin comprises a crystalline resin with a melting point in the range from 50 to 120° C. and an average volume particle size in the range from 3.0 to 7.5 &mgr;m, while an average value of the BET specific areas of said toner mother particles is in the range from 0.6 to 3.0 m2/g. The electrophotographic toner manufacturing method comprises the steps of coalescing or associating the binding resin particles with colorant particles, and cooling the aggregated particles at the rate of at least 1° C.Type: ApplicationFiled: December 2, 2002Publication date: June 5, 2003Applicant: Fuji Xerox Co., Ltd.Inventors: Hirokazu Hamano, Manabu Serizawa, Katsumi Daimon, Yuka Ishihara, Norihito Fukushima, Takashi Imai
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Patent number: 6569592Abstract: Provided is an image forming method capable of forming an image at a high speed, simultaneously performing a low temperature fusing property and hot offset resistance and controlling gloss. The image forming method includes a developing step of forming a toner image by developing an electrostatic latent image formed on a latent image holding member by a developer containing at least a toner, a transferring step of forming a transfer image by transferring the toner image formed on the latent image holding member onto a transfer material, and a fusing step of fusing the toner image transferred on the transfer material. In the image forming method, the toner contains at least a colorant and a binder resin in which a principal component is a crystalline resin and the fusing step is performed by a fusing apparatus having a heat-fixing roll and an endless belt.Type: GrantFiled: December 14, 2001Date of Patent: May 27, 2003Assignee: Fuji Xerox Co., Ltd.Inventors: Yuka Ishihara, Katsumi Daimon, Manabu Serizawa, Hirokazu Hamano, Norihito Fukushima, Takashi Imai
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Publication number: 20030091924Abstract: The present invention provides an image forming method for efficiently thermoelectrically transferring and fixing a toner image formed on an electrostatic latent image carrier without scattering of the toner. The image forming method comprises the steps of charging a surface of an electrostatic latent image carrier; exposing the charged surface of the electrostatic latent image carrier to a light beam using optical data corresponding to image data to form a latent image; developing the latent image formed on the surface of the electrostatic latent image carrier with a developer for electrophotography containing a toner for electrophotography to form a toner image; and thermoelectrically transferring the toner image formed on the surface of said electrostatic latent image carrier onto a surface of a recording medium and simultaneously fixing thereon. The toner for electrophotography is comprised of a crystalline polyester resin, the surface temperature of a fixing unit therein is higher by 10° C.Type: ApplicationFiled: November 8, 2002Publication date: May 15, 2003Applicant: FUJI XEROX CO., LTD.Inventors: Katsumi Daimon, Takashi Imai, Manabu Serizawa, Hirokazu Hamano, Norihito Fukushima, Yuka Ishihara
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Publication number: 20030054280Abstract: Provided is an image forming method capable of forming an image at a high speed, simultaneously performing a low temperature fusing property and hot offset resistance and controlling gloss. The image forming method includes a developing step of forming a toner image by developing an electrostatic latent image formed on a latent image holding member by a developer containing at least a toner, a transferring step of forming a transfer image by transferring the toner image formed on the latent image holding member onto a transfer material, and a fusing step of fusing the toner image transferred on the transfer material.Type: ApplicationFiled: December 14, 2001Publication date: March 20, 2003Applicant: FUJI XEROX CO., LTD.Inventors: Yuka Ishihara, Katsumi Daimon, Manabu Serizawa, Hirokazu Hamano, Norihito Fukushima, Takashi Irnai
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Publication number: 20030027073Abstract: An image forming method makes the warming-up time short, enables the formation of high-quality images even when fixing is performed continuously at high speed, and restrains degradations of the image quality, such as non-uniformity of gloss and non-uniformity of coloration even under high-temperature and high-humidity conditions. The method uses a toner that is wide in fixing range and is especially excellent in low-temperature fixing property. The method contains a process of melting and thereby fixing a toner image formed by unfixed toner, by heating a heating member that is in contact with the toner image. The surface of the heating member or its vicinity that is in contact with the toner image generates heat, and the toner contains at least a colorant and a binder resin having a crystalline resin with a number average molecular weight of 1500 or more as the main component.Type: ApplicationFiled: December 14, 2001Publication date: February 6, 2003Applicant: FUJI XEROX CO., LTD.Inventors: Manabu Serizawa, Katsumi Daimon, Hirokazu Hamano, Yuka Ishihara, Norihito Fukushima, Takashi Imai
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Patent number: 6242146Abstract: A carrier for two-component electrostatic-charged image developer, at least the surface of which is coated with a resin, is provided. The apparent density &rgr; (g/cm3) of the carrier, the mean particle diameter D (cm) of the carrier, and the specific area S (cm2/g) of the carrier core material satisfy the following conditions: 600≦S≦1500 10/(D×&rgr;)−S≦300. A two-component developer and an image-forming process using the carrier are also provided.Type: GrantFiled: February 7, 2000Date of Patent: June 5, 2001Assignee: Fuji Xerox Co., Ltd.Inventors: Yuka Ishihara, Hiroshi Nakazawa, Akihiro Iizuka, Yoshifumi Iida, Kaori Oishi, Tomohito Nakajima, Takashi Imai, Masanori Ichimura
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Patent number: 6214512Abstract: In an image forming method having the step of developing an electrostatic latent image on an electrostatic latent image carrying member using a toner layer on a developer carrying member, the step of transferring the developed toner image onto a belt transfer body 7 which is a first transfer body, and the step of transferring the toner image formed on the belt transfer body 7 onto a second transfer body 11, the surface resistance of the belt transfer body 7 is 108 to 1015 &OHgr;·cm, the toner is composed of at least resin particles containing a binding resin and a coloring material, and an additive, and the additive contains particles whose volume resistance is 107 to 1013 &OHgr;·cm.Type: GrantFiled: January 14, 1998Date of Patent: April 10, 2001Assignee: Fuji Xerox Co., Ltd.Inventors: Hiroshi Takano, Yuka Ishihara, Takashi Imai, Masanori Ichimura
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Patent number: 6001527Abstract: The present invention provides an electrostatic image developer comprising a toner and a carrier wherein the toner includes toner particles having an average particle diameter of 3 to 9 .mu.m, a hydrophobic silica microparticles having a BET specific surface area of 40 to 120 m.sup.2 /g, and a hydrophobic titanium compound microparticles having a BET specific surface area of 40 to 250 m.sup.2 /g; and wherein the carrier is a resin coated carrier having a coating layer of a resin. The electrostatic image developer can improve the environmental dependency of charging, power fluidity, resistance to caking of a toner and reduced change in charging with time course to provide an image with an excellent image quality for a long period of time.Type: GrantFiled: December 19, 1997Date of Patent: December 14, 1999Assignee: Fuji Xerox Co., Ltd.Inventors: Yuka Ishihara, Masanori Ichimura, Takashi Imai, Hiroshi Takano, Hiroshi Nakazawa, Yoshifumi Iida, Susumu Yoshino
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Patent number: 5884129Abstract: An electrostatic-image developer which comprises: (i) a toner comprising: (a) toner particles containing carbon black in an amount of from 6 to 8% by weight based on the weight of the toner particles and having a volume-average particle diameter of from 3 to 9 .mu.m; and (b) an external additive; and (ii) a resin-coated carrier having a volume resistivity of from 10.sup.7 to 10.sup.11 .OMEGA..multidot.cm in an electric field of 10.sup.3.8 V/cm and an average particle diameter of from 30 to 60 .mu.m. Also disclosed are a process for forming a black image and a process for forming a full-color image each using the electrostatic-image developer.Type: GrantFiled: May 27, 1997Date of Patent: March 16, 1999Assignee: Fuji Xerox Co., Ltd.Inventors: Masanori Ichimura, Michio Take, Hidekazu Yaguchi, Masaki Hashimoto, Takashi Imai, Hiroshi Takano, Masahiro Takagi, Akihiro Iizuka, Yuka Ishihara
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Patent number: 5849451Abstract: An electrophotographic dry toner comprising toner particles having externally added thereto fine particles of an inorganic compound having been surface treated with an amphoteric surface active agent. The toner is excellent in fluidity, anti-caking properties, charging properties, and environmental stability and provides excellent images free from defects such as black spots.Type: GrantFiled: July 17, 1997Date of Patent: December 15, 1998Assignee: Fuji Xerox Co., Ltd.Inventors: Yuka Ishihara, Chiaki Suzuki, Tetsu Torigoe, Atuhiko Eguchi, Takayoshi Aoki
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Patent number: 5804351Abstract: A toner for electrostatic-image development which comprises toner particles comprising a colorant and a binder resin, the toner particles having a volume-average particle diameter of from 3 to 9 .mu.m and a particle size distribution satisfying the following expressions (1) and (2):D16(v)/D50(v).ltoreq.1.475-0.036.times.D50(v) (1)D50(p)/D84(p).ltoreq.1.45 (2)wherein D16(v) and D50(v) represent, in terms of absolute value, a cumulative 16% diameter (.mu.m) and a cumulative 50% diameter (.mu.m), respectively, of a cumulative volume particle diameter distribution of the toner particles depicted from the larger diameter side, and D50(p) and D84(p) represent, in terms of absolute value, a cumulative 50% diameter (.mu.m) and a cumulative 84% diameter (.mu.m), respectively, of a cumulative population particle diameter distribution of the toner particles depicted from the larger diameter side.Type: GrantFiled: October 16, 1996Date of Patent: September 8, 1998Assignee: Fuji Xerox Co., Ltd.Inventors: Hiroshi Takano, Masanori Ichimura, Masaki Hashimoto, Hideyuki Akagi, Kazuya Furuta, Koji Fukushima, Masahiro Takagi, Kensaku Togao, Satoru Ishigaki, Michio Take, Yuka Ishihara