Patents by Inventor Sueko Sakai
Sueko Sakai 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: 7348119Abstract: The present invention provides a toner for developing an electrostatic latent image including: toner mother particles containing a binder resin and a colorant; and manganese compound particles having a ?-type crystalline structure, the production method thereof, and a developer containing the toner.Type: GrantFiled: June 28, 2005Date of Patent: March 25, 2008Assignee: Fuji Xerox Co., Ltd.Inventors: Tetsu Torigoe, Noriyoshi Takahashi, Teruo Sakai, legal representative, Emi Takahashi, Teigen Ri, Sueko Sakai
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Patent number: 7303846Abstract: 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: GrantFiled: March 15, 2005Date of Patent: December 4, 2007Assignee: Fuji Xerox Co., Ltd.Inventors: Teruo Sakai, legal representative, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Sueko Sakai, deceased
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Patent number: 7160662Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 ?cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.Type: GrantFiled: December 11, 2003Date of Patent: January 9, 2007Assignee: Fuji Xerox Co., Ltd.Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
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Publication number: 20060210901Abstract: The present invention provides a toner for developing an electrostatic latent image including: toner mother particles containing a binder resin and a colorant; and manganese compound particles having a ?-type crystalline structure, the production method thereof, and a developer containing the toner.Type: ApplicationFiled: June 28, 2005Publication date: September 21, 2006Applicant: FUJI XEROX CO., LTD.Inventors: Tetsu Torigoe, Noriyoshi Takahashi, Sueko Sakai, Teruo Sakai, Emi Takahashi, Teigen Ri
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Patent number: 7094514Abstract: The present invention relates to an image forming method wherein the surface of an electrophotographic photoreceptor contains a compound having an unsaturated double bond, a toner for electrostatic latent image development has a binder resin obtained by polymerizing a polymerizable monomer having a vinyl double bond, has at least one kind of metal oxide particles and/or metal nitride particles on the surface of the toner and has a shape factor SF1 of 110 to 140, and the storage of elastic modulus at 160° C. (G?(160)) of the toner for electrostatic latent image development is in a predetermined range.Type: GrantFiled: September 12, 2003Date of Patent: August 22, 2006Assignee: Fuji Xerox Co., Ltd.Inventors: Manabu Serizawa, Hidekazu Yaguchi, Tsutomu Kubo, Kazuhiko Yanagida, Shigeru Seitoku, Yasuo Matsumura, Sueko Sakai, Hiroyuki Tanaka
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Patent number: 7095974Abstract: An image forming method including a charging step, a latent image forming step, a developing step, a transfer step, and a cleaning step, wherein remaining toner recovered in the cleaning step is used as recycled toner, and a ratio of the recycled toner to a total amount of supply toner supplied to a developer is 15% by weight or greater.Type: GrantFiled: December 12, 2003Date of Patent: August 22, 2006Assignee: Fuji Xerox Co., Ltd.Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
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Publication number: 20060115757Abstract: A toner for development of an electrostatic latent image, comprises: a binder resin; a colorant; and a release agent, wherein the binder resin has a weight average molecular weight of 20,000 to 40,000, and when a carbon content and a sulfur content of the toner measured using X-ray fluorescence are represented by [C] % and [S] %, respectively, [S]/[C] satisfies expression (1): 0.0002?[S]/[C]?0.0030 ??(1).Type: ApplicationFiled: May 26, 2005Publication date: June 1, 2006Applicant: FUJI XEROX CO., LTD.Inventors: Emi Takahashi, Noriyoshi Takahashi, Sueko Sakai, Teruo Sakai, Tetsu Torigoe, Teigen Ri
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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: 20040234877Abstract: The present invention relates to an image forming method including: a charging step; an electrostatic latent image forming step; a developing step; a transfer step; a fixing step; and a cleaning step, wherein an electrostatic latent image developing agent comprises a toner and a carrier, wherein particles which have a volume resistivity of at least 1×1014 &OHgr;cm and an average primary particle diameter of 50 nm or less has a higher covering ratio than other particles on the toner particle surfaces, a shape factor SF1 of the toner is in the range of from 100 to 140, the carrier is a resin coated carrier, and at least a coating resin layer comprises a positively charging resin and a quaternary ammonium salt compound.Type: ApplicationFiled: December 11, 2003Publication date: November 25, 2004Applicant: FUJI XEROX CO., LTD.Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
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Publication number: 20040234310Abstract: An image forming method including a charging step, a latent image forming step, a developing step, a transfer step, and a cleaning step, wherein remaining toner recovered in the cleaning step is used as recycled toner, and a ratio of the recycled toner to a total amount of supply toner supplied to a developer is 15% by weight or greater.Type: ApplicationFiled: December 12, 2003Publication date: November 25, 2004Applicant: FUJI XEROX CO., LTD.Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
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Publication number: 20040185367Abstract: The present invention relates to an image forming method wherein the surface of an electrophotographic photoreceptor contains a compound having an unsaturated double bond, a toner for electrostatic latent image development has a binder resin obtained by polymerizing a polymerizable monomer having a vinyl double bond, has at least one kind of metal oxide particles and/or metal nitride particles on the surface of the toner and has a shape factor SF1 of 110 to 140, and the storage of elastic modulus at 160° C. (G′(160)) of the toner for electrostatic latent image development is in a predetermined range.Type: ApplicationFiled: September 12, 2003Publication date: September 23, 2004Applicant: FUJI XEROX CO., LTD.Inventors: Manabu Serizawa, Hidekazu Yaguchi, Tsutomu Kubo, Kazuhiko Yanagida, Shigeru Seitoku, Yasuo Matsumura, Sueko Sakai, Hiroyuki Tanaka
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Patent number: 6042979Abstract: The present invention provides toner for an electrostatic latent image developer, said toner being excellent in fluidity, chargeability, developability, transferability, and freedom from fogging on a photoreceptor and contamination of the interior of a developing device. The toner for an electrostatic latent image developer comprises spherical toner particles characterized by a shape index ML.sup.2 /A of less than 125 and has a correlation coefficient between X.sup.2/3 and Y, obtained by linear regression with respect to a straight line which passes through the origin of coordinate axes, of more than 0.6 where X is the light emitting voltage due to the carbon derived from the binder resin of the toner particles and Y is the light emitting voltage due to the element derived from the external additive.Type: GrantFiled: November 27, 1998Date of Patent: March 28, 2000Assignee: Fuji Xerox Co., Ltd.Inventors: Kaori Ohishi, Chiaki Suzuki, Masahiro Takagi, Satoshi Inoue, Tetsuya Taguchi, Sueko Sakai
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Patent number: 5821022Abstract: A carrier for developing an electrostatic latent image comprising a core material coated with a resin layer, wherein the F/N ratio of the surface of the resin layer ranges from 1 to 20. It is desirable that the resin layer include resin particles containing a nitrogen atom, that the average particle diameter of the nitrogen-atom-containing resin be in a range from 0.1 to 2 .mu.m, that the thickness of the resin layer be in a range from 0.1 to 10 .mu.m, that the resin layer include an electroconductive material which is in a condition to be dispersed in the resin layer, that the electroconductive material be made of carbon black, and that the average particle diameter of the carrier for developing an electrostatic latent image be in a range from 30 to 150 .mu.m. The carrier for developing an electrostatic latent image, which is long-lived, provided with a charging capability unchanged over time, and is capable of effectively preventing fogging are provided.Type: GrantFiled: May 19, 1997Date of Patent: October 13, 1998Assignee: Fuji Xerox Co., Inc. Ltd.Inventors: Kaori Ohishi, Susumu Yoshino, Satoshi Inoue, Chiaki Suzuki, Sueko Sakai
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Patent number: 5821023Abstract: The present invention provides a long-life carrier for developing an electrostatic latent image to be used in such field of applications as electrostatic photography and electrostatic recording, a developer of an electrostatic latent image utilizing said carrier, a method for forming an image and an image forming apparatus by using said developer. By use of the foregoing qualities, a high-quality image can be obtained.Type: GrantFiled: May 23, 1997Date of Patent: October 13, 1998Assignee: Fuji Xerox Co., Ltd.Inventors: Yuusaku Shibuya, Yasuhiro Oya, Haruhide Ishida, Susumu Yoshino, Hirokazu Hamano, Kaori Ohishi, Satoshi Inoue, Jun Igarashi, Chiaki Suzuki, Sueko Sakai
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Patent number: 5456990Abstract: A magnetic toner comprising a binder resin having dispersed therein a magnetic powder is disclosed, wherein the magnetic toner has a volume average particle diameter (D.sub.50) of from 4 to 9 .mu.m, the magnetic powder has a number average particle diameter of from 0.15 to 0.25 .mu.m (hereinafter simply referred to as a particle diameter), a BET specific surface area of from 6 to 8 m.sup.2 /g, and a residual magnetization of from 7 to 10 emu/g, the magnetic powder is present in an amount of from 30 to 70% based on the total weight of the magnetic toner, and the magnetic toner has adhered to the surface thereof silica powder having been rendered hydrophobic. The magnetic toner exhibits superior performance in terms of image density, definition, dot and fine line reproducibility, and environmental stability.Type: GrantFiled: March 17, 1994Date of Patent: October 10, 1995Assignee: Fuji Xerox Co., Ltd.Inventors: Seiichi Takagi, Toshiyuki Yano, Hiroe Okuyama, Teruo Masukawa, Sueko Sakai, Emi Takahashi
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Patent number: 4973538Abstract: A toner for development of a latent electrostatic image containing a colorant and a binder resin formed of a mixture of a low-molecular weight component and a high-molecular weight component. Both the low-molecular weight component and high-molecular weight component are made from a styrene-acrylic copolymer where the weight ratio (A) of styrene to acrylic monomer in the low-molecular weight polymer component and an the weight ratio (B) of styrene to acrylic monomer in the high-molecular weight polymer component satisfies the relationship A/B.ltoreq.1.3. The mixing ratio of the low-molecular weight and high-molecular weight components is within the range of from 80:20 to 40:60. The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) of the low-molecular weight polymer component satisfies the relationship Mw/Mn.ltoreq.3.0.Type: GrantFiled: February 9, 1989Date of Patent: November 27, 1990Assignee: Fuji Xerox Co., Ltd.Inventors: Chiaki Suzuki, Masayoshi Shinoki, Koichi Kumashiro, Sueko Sakai, Emi Takahashi