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).

  • Patent number: 7348119
    Abstract: 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: Grant
    Filed: June 28, 2005
    Date of Patent: March 25, 2008
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tetsu Torigoe, Noriyoshi Takahashi, Teruo Sakai, legal representative, Emi Takahashi, Teigen Ri, Sueko Sakai
  • Patent number: 7303846
    Abstract: 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: Grant
    Filed: March 15, 2005
    Date of Patent: December 4, 2007
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Teruo Sakai, legal representative, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Sueko Sakai, deceased
  • Patent number: 7160662
    Abstract: 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: Grant
    Filed: December 11, 2003
    Date of Patent: January 9, 2007
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
  • Publication number: 20060210901
    Abstract: 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: Application
    Filed: June 28, 2005
    Publication date: September 21, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Tetsu Torigoe, Noriyoshi Takahashi, Sueko Sakai, Teruo Sakai, Emi Takahashi, Teigen Ri
  • Patent number: 7094514
    Abstract: 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: Grant
    Filed: September 12, 2003
    Date of Patent: August 22, 2006
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Manabu Serizawa, Hidekazu Yaguchi, Tsutomu Kubo, Kazuhiko Yanagida, Shigeru Seitoku, Yasuo Matsumura, Sueko Sakai, Hiroyuki Tanaka
  • Patent number: 7095974
    Abstract: 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: Grant
    Filed: December 12, 2003
    Date of Patent: August 22, 2006
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
  • Publication number: 20060115757
    Abstract: 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: Application
    Filed: May 26, 2005
    Publication date: June 1, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Emi Takahashi, Noriyoshi Takahashi, Sueko Sakai, Teruo Sakai, Tetsu Torigoe, Teigen Ri
  • Publication number: 20060046173
    Abstract: 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: Application
    Filed: March 15, 2005
    Publication date: March 2, 2006
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Sueko Sakai, Yuka Ishihara, Atsuhiko Eguchi, Masahiro Okita, Jun Igarashi, Koichi Sugiyama, Susumu Yoshino, Teruo Sakai
  • Publication number: 20040234877
    Abstract: 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: Application
    Filed: December 11, 2003
    Publication date: November 25, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu Yoshino, Yoshifumi Iida, Seki Yamaguchi, Motoko Sakai, Sueko Sakai
  • Publication number: 20040234310
    Abstract: 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: Application
    Filed: December 12, 2003
    Publication date: November 25, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Susumu Yoshino, Motoko Sakai, Yoshifumi Iida, Sueko Sakai, Seki Yamaguchi
  • Publication number: 20040185367
    Abstract: 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: Application
    Filed: September 12, 2003
    Publication date: September 23, 2004
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Manabu Serizawa, Hidekazu Yaguchi, Tsutomu Kubo, Kazuhiko Yanagida, Shigeru Seitoku, Yasuo Matsumura, Sueko Sakai, Hiroyuki Tanaka
  • Patent number: 6042979
    Abstract: 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: Grant
    Filed: November 27, 1998
    Date of Patent: March 28, 2000
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kaori Ohishi, Chiaki Suzuki, Masahiro Takagi, Satoshi Inoue, Tetsuya Taguchi, Sueko Sakai
  • Patent number: 5821023
    Abstract: 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: Grant
    Filed: May 23, 1997
    Date of Patent: October 13, 1998
    Assignee: 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
  • Patent number: 5821022
    Abstract: 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: Grant
    Filed: May 19, 1997
    Date of Patent: October 13, 1998
    Assignee: Fuji Xerox Co., Inc. Ltd.
    Inventors: Kaori Ohishi, Susumu Yoshino, Satoshi Inoue, Chiaki Suzuki, Sueko Sakai
  • Patent number: 5456990
    Abstract: 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: Grant
    Filed: March 17, 1994
    Date of Patent: October 10, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Seiichi Takagi, Toshiyuki Yano, Hiroe Okuyama, Teruo Masukawa, Sueko Sakai, Emi Takahashi
  • Patent number: 4973538
    Abstract: 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: Grant
    Filed: February 9, 1989
    Date of Patent: November 27, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Chiaki Suzuki, Masayoshi Shinoki, Koichi Kumashiro, Sueko Sakai, Emi Takahashi