Having Specified Toner Particle Size Distribution Patents (Class 430/110.4)
  • Patent number: 6963711
    Abstract: A developing device for electrophotographic image has a developing mechanism having a developer carrier for carrying a developer along a preset circulating route including a developing area and a developer restricting element for restricting the developer on the developer carrier, and a developer supply mechanism having a storing unit. The storing unit is filled with a start-up developer in the vicinity of the developer carrier and a replenishing developer remoter than the start-up developer from the developer carrier. The start-up developer and the replenishing developer have different grain sizes or grain size distributions. Further, a developing method for electrophotograhic image has the steps of using the start-up developer at an initial state of use of the developing mechanism, and using the replenishing developer differed in grain size or grain size distribution from the start-up developer after an end of the initial state of use of the developing mechanism.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: November 8, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Tomoaki Tanaka, Satoshi Takezawa, Yoshimichi Katagiri, Masae Nakamura
  • Patent number: 6946230
    Abstract: Compositions and methods for electrographic image development, wherein the image development process employs a two-component developer that includes toner particles having a radius RT and magnetic carrier particles having a radius RC, wherein RC is preferably less than about 5RT and is more preferably less than or equal to about 3RT.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: September 20, 2005
    Assignee: Heidelberger Druckmaschinen AG
    Inventors: Eric C. Stelter, Joseph E. Guth, Ulrich Mutze
  • Patent number: 6911289
    Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: June 28, 2005
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Patent number: 6904251
    Abstract: The image forming apparatus includes: a plurality of image forming units each having an image bearing member and a developing unit; and a transfer member provided to be able to contact the plurality of image bearing members. The toner used in at least one of the plurality of developing units contains a toner particle group with a particle size of 12.7 ?m or more, a ratio of the toner particle group to the entire toner being 1.0% or less. Accordingly, incomplete transfer can be prevented.
    Type: Grant
    Filed: October 28, 2003
    Date of Patent: June 7, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Uyama, Masahide Kinoshita, Kenichi Iida
  • Patent number: 6902856
    Abstract: An electrophotographic image forming method is disclosed. In the method each of a plurality of toner images formed on the latent image bearing body is sequentially onto an intermediate transfer body, and the transferred image on the intermediate transfer body is transferred to an image forming support, and fixed using a heating roller fixing system, and the toner satisfies ratio (Dv50/Dp50) is from 1.00 to 1.15; ratio (Dv75/Dp75) is from 1.00 to 1.20; and the content ratio of toner having a particle diameter of at most 0.7×(Dp50) is less than or equal to 10 percent by number. Dv50, Dp50, Dv75 and Dp75 are specified in the specification.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: June 7, 2005
    Assignee: Konica Corporation
    Inventors: Asao Matsushima, Hiroyuki Kozuru, Meizo Shirose, Hiroshi Yamazaki
  • Patent number: 6887638
    Abstract: A toner for developing an electrostatic latent image is provided that is excellent in releasing property upon fixing and shape controllability upon production of the toner. The toner for developing electrostatic latent image has a number average molecular weight in a range of from 10,000 to 30,000 and a ratio of a Z average molecular weight and a weight average molecular weight in a range of from 3.0 to 6.0.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: May 3, 2005
    Assignee: Fuji Xoerox Co., Ltd.
    Inventors: Takao Ishiyama, Shuji Sato, Hiroshi Kamada, Masakazu Iijima
  • Patent number: 6875549
    Abstract: A toner showing a high transferability and suitable for use in cleanerless image forming system is formed of toner particles comprising at least a binder resin and magnetic iron oxide. The toner is characterized by a specific circularity distribution relative to its weight-average particle size and a controlled degree of surface-exposed magnetic iron oxide providing an extract solution with hydrochloric acid showing an absorbance of 1.0-2.5 at a wavelength of 340 nm. The toner is suitably produced by a production system including a rotary mechanical pulverizer and a one-pass surface treatment apparatus for continuously applying a mechanical impact force to pulverized toner particles therein.
    Type: Grant
    Filed: April 8, 2002
    Date of Patent: April 5, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhisa Yamazaki, Hirohide Tanikawa, Hiroshi Yusa, Takashige Kasuya, Yoshihiro Ogawa, Shuhei Moribe
  • Patent number: 6873814
    Abstract: A developing device including a developer containing magnetic toner grains and includes a main pole for development disposed in a sleeve. Flux density generated by the magnetic pole in a direction normal to the surface of the sleeve outside of the surface has an attenuation ratio of 50% or above. The toner grains have a weight mean grain size of 6.0 ?m to 8.0 ?m while the toner grains having grain sizes of 5 ?m and below occupy 40% to 80% of the entire developer. The toner grains have magnetization strength of 10 emu/g to 25 emu/g in a magnetic field of 5 kOe or magnetization strength of 7 emu/g to 20 emu/g in a magnetic field of 1 kOe. The toner grains reduce toner scattering and image defects despite that they are magnetic, thereby implementing ultrahigh resolution.
    Type: Grant
    Filed: November 1, 2002
    Date of Patent: March 29, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Tokuya Ohjimi, Fumihiro Sasaki, Hiroto Higuchi, Maiko Kondo, Toshio Koike, Atsushi Sampe, Masayuki Yamane, Kunihiro Ohyama, Junichi Sano, Takeyoshi Sekine
  • Patent number: 6866978
    Abstract: The toner comprises a white color toner particle and an external additive containing a hydrophobic titanium oxide particle. The absolute charge value of the toner is 20 to 50 ?C/g. The developer contains a white color toner particle and a carrier having a surface coated with a resin containing a fluororesin.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: March 15, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yoshifumi Iida, Suk Kim, Masanori Ichimura
  • Patent number: 6868252
    Abstract: In an image forming apparatus, after the development of a latent image formed on an image carrier effected by using toner, which has a volume mean grain size of 5 ?m to 10 ?m and in which 60 number percent to 80 number percent of toner grains have a grain size of 5 ?m or below, and the transfer of the resulting image to a recording medium, a cleaning device of the present invention removes the toner left on the image carrier with a fur brush. The fur brush is capable of contacting the surface of the image carrier with density high enough to block the toner grains having the above grain size.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: March 15, 2005
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasushi Akiba
  • Patent number: 6864031
    Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same. In the present invention, used for the electrostatically charged-image holder described above having a radius of curvature of 18 mm or less in a development effective range is the electrophotographic developer which is a two-component developer comprising a toner comprising at least a binder and a colorant and a carrier which is coated with a resin and has a weight average particle diameter of 40 to 100 ?m, wherein the above toner has a volume average particle diameter of 8 to 11.5 ?m, and the toner particles having a diameter of 6.35 ?m or less account for 20 number % or less.
    Type: Grant
    Filed: January 5, 2004
    Date of Patent: March 8, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshihisa Ishida, Tatsuo Imafuku, Junichi Saito, Takahiro Bito
  • Patent number: 6852462
    Abstract: A toner comprising: a binder resin which is at least a resin selected from the group consisting of modified polyester resins and unmodified polyester resins; and a colorant; the product toner having a volume-average particle diameter (Dv) to a number-average particle diameter (Dn) ratio (Dv/Dn) ranging from 1.00 to 1.30, and the toner having a shape factor SF-1 ranging from 140 to 200.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: February 8, 2005
    Assignee: Ricoh Company Limited
    Inventors: Shigeru Emoto, Tsunemi Sugiyama, Hiroshi Yamashita, Shinichiro Yagi, Masami Tomita, Hiroshi Yamada, Naohiro Watanabe, Toshiki Nanya
  • Patent number: 6849369
    Abstract: Toner particles including a binder resin; a colorant; and a particulate resin which is present at least on a surface of the toner particles and which has a glass transition temperature of form 50 to 90° C., wherein a ratio (Dv/Dn) of a volume average particle diameter (Dv) of the toner particles to a number average particle diameter (Dn) thereof is from 1.00 to 1.40 and the surface of the toner particles is covered with the particulate resin at a covering ratio of from 1 to 90 %. A method for manufacturing the toner particles is provided. A developer including a toner including the toner particles is provided. A developing method using a toner including the toner particles is provided. A toner container containing the toner particles is provided.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: February 1, 2005
    Assignee: Ricoh Company, Limited
    Inventors: Shinichiro Yagi, Masami Tomita, Toshiki Nanya, Shigeru Emoto, Hiroshi Yamada, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Tadao Takigawa
  • Patent number: 6846604
    Abstract: A toner composition including toner particles including mother toner particles, which include a binder resin, a colorant and a release agent, and a charge controlling agent which is located on a surface of the mother toner particles and fixed thereon, wherein the toner particles have a spherical degree of from 0.960 to 1.000 and a specific surface area of from 0.70 to 2.5 m2/g. The toner composition optionally includes an external additive which is present on the surface of the toner particles.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: January 25, 2005
    Assignee: Ricoh Company Limited
    Inventors: Shigeru Emoto, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Hiroshi Yamada, Masami Tomita
  • Patent number: 6844126
    Abstract: An electrostatic latent image developing toner is disclosed. The toner particles has an average of circularity of 0.94 to 0.98; an average of circle equivalent diameter of 2.6 to 7.4 ?m; and gradient of the circularity with respect to the circle-equivalent diameter of ?0.050 to ?0.010.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: January 18, 2005
    Assignee: Konica Corporation
    Inventors: Ken Ohmura, Asao Matsushima, Shiro Hirano, Hiroshi Yamazaki
  • Patent number: 6838220
    Abstract: A toner for developing an electrostatic image, a process for producing the same, a developer for developing an electrostatic image and a process for forming an image are disclosed. The toner contains a resin, a colorant and a releasing agent, in which the toner has protrusions having a height of about from 0.05 to 2 ?m, a part of the protrusions encompasses the releasing agent, and a proportion of elements derived from the releasing agent is about 10% by atom or less based on elements on a surface of the toner that is quantitatively determined by X-ray photoelectron spectroscopy.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: January 4, 2005
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yasuo Matsumura, Takao Ishiyama, Hiroshi Takano, Masaaki Suwabe, Shuji Sato
  • Publication number: 20040241566
    Abstract: An electrophotographic image forming apparatus capable of reliably forming an image with density gradation, one which does not have a low-quality appearance. The estimated average halftone granularity of the toner image after developing but before electrostatic transfer was set at 0.25 or less. The average halftone granularity was found by measuring the granularity of a toner image at locations of different average brightness by means of newly proposed formula, and averaging the measured values for which the average brightness is 40 to 80. The estimated average halftone granularity was obtained by estimating the average halftone granularity of the toner image on a photoreceptor by means of a newly proposed method.
    Type: Application
    Filed: March 23, 2004
    Publication date: December 2, 2004
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Patent number: 6823159
    Abstract: An image forming apparatus includes an electrophotographic photosensitive member rotated at a peripheral speed of 150 mm/second or more and a specific toner. The toner has a weight-average particle diameter from 5 to 12 &mgr;m, and of the toner having a circle-equivalent diameter of 3 &mgr;m or more, particles with a circularity of 0.900 or more are present at a rate of 90% or more in a number-based cumulative valve. The toner also satisfies one of two sets of conditions defined by the relationship between a cut rate and a weight-average particle diameter and the relationship between a number-based cumulative valve and a weight-average particle diameter. The cut rate Z is represented by the expression: Z=(1−B/A)×100 wherein A is a concentration of all the measured particles and B is a concentration of the measured particles whose circle-equivalent diameters are 3 &mgr;m or more.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: November 23, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroaki Sakai, Seiji Saito, Takeshi Kawamura
  • Publication number: 20040229143
    Abstract: A toner for electrophotography contains a binder resin, a colorant and a releasing agent and has a viscosity, a storage modulus (G′) and a loss modulus (G″), in which the viscosity is 1×103 Pa.s or more and a loss tangent (tan &dgr;) as the ratio of G′ to G″ is 0.4 or more at temperatures from 140° C. to 170° C.
    Type: Application
    Filed: February 24, 2004
    Publication date: November 18, 2004
    Inventors: Kazuhiko Umemura, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Hideki Sugiura, Tomoyuki Ichikawa, Shinya Nakayama, Koichi Sakata, Tomoko Utsumi
  • Patent number: 6819893
    Abstract: An image forming apparatus uses a developer that includes toner with volume average particle size between 5 &mgr;m and 10 &mgr;m and 60 to 80 number percentage particles having a particle size less than or equal to 5 &mgr;m. A charging unit charges a latent image carrier. The charging unit and the latent image carrier are arranged in such a manner that they do no make a physical contact.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: November 16, 2004
    Assignee: Ricoh Company, Ltd.
    Inventor: Nobuo Kikuchi
  • Publication number: 20040223786
    Abstract: In an image forming apparatus having at least an amorphous silicon photosensitive member, a magnetic toner developing means and a color developer developing means, the magnetic toner has a weight-average particle diameter (D4) of from 4.0 &mgr;m to 10.0 &mgr;m and a ratio thereof to number-average particle diameter (D1), D4/D1, of from 1.0 to 2.0, and the number of magnetic particles not passing through a mesh with an opening of 34 &mgr;m which are contained in the unit volume of the magnetic toner is from 3.5 to 105. This image forming apparatus can not easily cause faulty cleaning performance even in using the magnetic toner and the non-magnetic color toners in combination and has superior environmental stability and running stability even where toners made to have small particle diameter are used or process speed is high.
    Type: Application
    Filed: April 27, 2004
    Publication date: November 11, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yusuke Hasegawa, Yuichi Mizoo, Tadashi Dojo, Nene Shibayama, Tomohisa Sano
  • Patent number: 6806012
    Abstract: An electrostatic image developing toner is disclosed. The resin of the toner particle has a cell structure and an average value of FERE-horizontal diameters of the cells is from 20 to 200 nm and a variation coefficient of the FERE-horizontal diameters of the cells is from 10 to 35%.
    Type: Grant
    Filed: September 16, 2002
    Date of Patent: October 19, 2004
    Assignee: Konica Corporation
    Inventors: Yasuko Yamauchi, Ken Ohmura, Masafumi Uchida
  • Patent number: 6806016
    Abstract: A toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 &mgr;m based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: October 19, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Manabu Ohno, Satoshi Yoshida, Satoshi Handa, Akira Hashimoto, Keiji Komoto
  • Publication number: 20040191659
    Abstract: A toner having a favorable fixability, excelling in charge stability, and capable of forming a image of retaining a high image density and a high resolution in long-term use is provided. That is, the toner of the present invention is a toner obtained by polymerizing a polymerizable monomer composition comprising a polymerizable monomer and a colorant, in which the polymerizable monomer composition is polymerized using a polymerization initiator comprising a redox initiator which includes an organic peroxide with a 10-hour half-life temperature of 86° C. or higher and an reducing agent; the toner has a ratio of a weight-average particle diameter to a number-average particle diameter of 1.40 or less; and the toner has top of a main-peak in a molecular weight range of 5,000 to 50,000 in a molecular weight distribution measured using GPC of the THF-soluble part thereof, including t-butanol with a content of 0.1 to 1,000 ppm.
    Type: Application
    Filed: December 4, 2003
    Publication date: September 30, 2004
    Inventors: Tatsuya Nakamura, Kenji Okado, Akira Hashimoto, Keiji Komoto
  • Publication number: 20040191663
    Abstract: The present invention relates to a non-magnetic one-component toner that is characterized by containing toner particles that have a volume-average particle size of 2 to 8 &mgr;m, a ratio of the volume-average particle size/number-average particle size of not more than 1.22, an average degree of roundness of not less than 0.92 and a Vickers hardness of not less than 13.5HV0.01 (10g), and also concerns a non-magnetic one-component contact developing device using such a toner and an image-forming apparatus using such a developing device.
    Type: Application
    Filed: June 27, 2003
    Publication date: September 30, 2004
    Applicant: MINOLTA CO., LTD.
    Inventors: Seishi Ojima, Hideaki Ueda
  • Publication number: 20040185356
    Abstract: Disclosed is a combination of developing agents by which letting Ry micrometer be the volume-average particle diameter of a yellow developing agent, and R micrometer be the volume-average particle diameter of a non-yellow color developing agent, R<Ry and 4<R<11, and letting Ty (° C.) be the softening point of the yellow developing agent, and T (° C.) be the average value of the softening points of non-yellow color developing agents, Ty>T.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Applicant: TOSHIBA TEC KABUSHIKI KAISHA
    Inventor: Tsuyoshi Ito
  • Publication number: 20040185363
    Abstract: A toner for developing an electrostatic image, comprising, a binder resin, a colorant, a charge control agent, and a parting agent, and wherein: a volume average particle diameter (Dv) of toner particles is 3 to 10 &mgr;m; a ratio (Dv/Dp) of Dv to a number average particle diameter (Dp) is 1 to 1.3; an average circle degree is 0.93 to 0.995; and location parameter of island-shaped separate phase is 25 number % or more, wherein the location parameter is the percentage of such sectional photo image of toner particles where a maximum diameter of island-shaped separate phase is 1 &mgr;m or more and an outermost portion of said island-shaped separate phase is present at the depth of 0.01 to 0.15 time of the particle diameter of each toner particle under the surface.
    Type: Application
    Filed: January 30, 2004
    Publication date: September 23, 2004
    Applicant: ZEON CORPORATION
    Inventor: Hiroto Kidokoro
  • Publication number: 20040166428
    Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.
    Type: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Publication number: 20040166429
    Abstract: A toner including toner particles including a binder resin and a release agent, wherein when the toner is molded into a plate upon application of a pressure of 478 kg/cm2, the toner plate has a surface having a coefficient of static friction of from 0.20 to 0.40. An image forming apparatus including an image bearing member, an image developer to form a toner image on the image bearing member, an image transferer configured to transfer the toner image on a receiving material and a fixer configured to fix the toner image thereon, wherein the apparatus has a waiting time not longer than 15 seconds, and a maximum power consumption not greater than 1.5 KW and 30 W in an image forming state and in a standby state, respectively, wherein the toner is the toner mentioned above.
    Type: Application
    Filed: February 26, 2004
    Publication date: August 26, 2004
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Bing Shu, Hiroaki Matsuda, Maiko Kondo
  • Patent number: 6780558
    Abstract: An electrophotographic image forming method is disclosed. The method comprises developing latent images each formed on a static latent image forming member by serially arranged plural image forming units each including a toner to form toner images, respectively, successively transferring the toner images onto an image support so as to form a piled up image, and fixing the piled up image by a fixing device having a rotatable heating member including a heater fixed therein and a pressing member, and in the method the toner for developing the latent image has a variation coefficient of the shape coefficient of not more than 16% and a number variation coefficient of the particle diameter distribution in number of not more than 27%.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: August 24, 2004
    Assignee: Konica Corporation
    Inventors: Hiroyuki Yamada, Hiroshi Yamazaki, Meizo Shirose, Shigenori Kouno
  • Publication number: 20040146795
    Abstract: A toner is used in an image forming process employing a toner recycling system and contains at least a modified polyester resin, a coloring agent, and a releasing agent. The toner has a volume-average particle diameter Dv, a number-average particle diameter Dn and a shape factor SF-1, wherein Dv is in a range from 4.0 &mgr;m to 6.0 &mgr;m, the ratio Dv/Dn of Dv to Dn is in a range from 1.00 to 1.30, and the shape factor SF-1 is in a range from 140 to 200.
    Type: Application
    Filed: January 20, 2004
    Publication date: July 29, 2004
    Inventors: Shigeru Emoto, Toshiki Nanya, Naohito Shimota, Maiko Kondo, Shinichiro Yagi, Hiroto Higuchi, Fumihiro Sasaki, Takahiro Honda, Junichi Awamura
  • Publication number: 20040146315
    Abstract: The present invention relates to an image-forming method and a image-forming device, wherein a specific photosensitive member, an exposing process and a toner are adopted in combination.
    Type: Application
    Filed: May 15, 2003
    Publication date: July 29, 2004
    Applicant: MINOLTA CO., LTD.
    Inventors: Hideaki Ueda, Shino Hirao, Mitsutoshi Nakamura, Mitsuyo Matsumoto
  • Publication number: 20040142267
    Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same.
    Type: Application
    Filed: January 5, 2004
    Publication date: July 22, 2004
    Applicant: Sharp Kabushika Kaisha
    Inventors: Toshihisa Ishida, Tatsuo Imafuku, Junichi Saito, Takahiro Bito
  • Patent number: 6764798
    Abstract: A two-component developer comprising a toner onto which a hydrophobic silica having an average particle size of 25 nm or more is externally added, and a carrier having a saturation magnetization of from 50 to 95 Am2/kg, wherein the carrier has a ratio of surface resistivity to volume resistivity of from 1×102 to 1×104 m−1 at an electric field strength of 100 V/cm; and a method for development comprising applying the above two-component developer to an electrophotographic device comprising a photoconductor having a peripheral speed of 400 mm/sec or more, and developing a latent image. The two-component developer can be used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: July 20, 2004
    Assignee: Kao Corporation
    Inventors: Masahito Yamazaki, Koji Kameyama, Koji Akiyama
  • Publication number: 20040137348
    Abstract: A chemically prepared toner for electrophotographic printers and method therefor using a unique polymeric dispersant. The chemically prepared toner includes agglomerated polymeric dispersant stabilized pigment particles, a fuser release agent, a charge control agent dispersion, and a self-stabilized essentially surfactant free latex binder. The polymeric dispersant includes at least three segments, a hydrophilic polymeric segment, a hydrophobic polymeric segment, and a protective colloid or reactive surfactant segment. The weight average molecular weight range of the dispersant ranges from about 5,000 to about 30,000, and a hydrophobicity ranging from about 10 to about 90 percent by weight. The chemically prepared toner includes agglomerated toner particles have a unimodal particles size distribution with a number average particle size (N) ranging from about 5.0 to about 8.5 microns and a volume average particle size (V) ranging from about 5.0 to about 8.5 microns.
    Type: Application
    Filed: November 6, 2003
    Publication date: July 15, 2004
    Inventors: Jing X. Sun, Bradley Leonard Beach
  • Publication number: 20040137356
    Abstract: A process contains in which heating and fixing an image of a toner on a recording medium is performed by heating one or more heat-transfer media by a heating element, and pressing the recording medium bearing the toner image to one of the heat-transfer media. At least one of the heat-transfer media is a belt heat-transfer medium with or without the application of an oil whose amount is 4 mg or less per A4 size, and the toner contain a binder resin and a releasing agent, has a weight-average particle diameter Dv of 3.0 to 7.0 &mgr;m, a particle diameter distribution Dv/Dn of 1.00 or more and 1.25 or less, wherein Dn is a number-average particle diameter, and an average shape factor SF-1 of 100 to 150 and contains toner particles having a shape factor SF-1 of 160 or more in an amount of 10% by number or less.
    Type: Application
    Filed: December 9, 2003
    Publication date: July 15, 2004
    Inventors: Masami Tomita, Hiroaki Matsuda
  • Publication number: 20040137347
    Abstract: The image forming method carries out reverse development with a developer that has a toner prepared by agglomerating resin particles in a water based medium.
    Type: Application
    Filed: December 22, 2003
    Publication date: July 15, 2004
    Applicant: Konica Corporation
    Inventors: Hiroshi Yamazaki, Hiroyuki Yamada, Meizo Shirose, Shigenori Kouno
  • Publication number: 20040126692
    Abstract: A toner used for an image forming method comprises steps of: limiting an amount of toner on a surface of a toner carrier by allowing a toner layer limiting member to be pressed to the surface of the toner carrier; and developing an electrostatic latent image formed on an electrostatic latent image carrier using the toner carried and transferred by the toner carrier, based on a non-magnetic single component development system, wherein the toner comprises toner particles having a volume average particle diameter of 3 to 9 &mgr;m, an arithmetic mean value of shape factor of 1.1 to 1.5, a coefficient of variation of shape factor of 16% or less, a ratio of rounded toner particle of 50% by number or more and a coefficient of variation of number particle diameter distribution of 26% or less, and a conveyance index of 2.0 to 10.0.
    Type: Application
    Filed: September 18, 2003
    Publication date: July 1, 2004
    Applicants: Konica Minolta Holdings, Inc., Minolta Co., Ltd.
    Inventors: Takao Yamanouchi, Masafumi Uchida, Masahiro Anno, Chikara Tsutsui, Takeshi Arai
  • Publication number: 20040126691
    Abstract: A toner for developing electrostatic latent images, having a specified volume-average particle size, an average degree of roundness, a standard deviation of the degree of roundness and surface properties D/d50 wherein a specified amount of fatty acid metal salt that has a specified volume-average particle size is externally added, and an image-forming method using such a toner.
    Type: Application
    Filed: November 14, 2003
    Publication date: July 1, 2004
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
    Inventors: Chikara Tsutsui, Masahiro Anno, Masahide Inoue, Katsunori Kurose
  • Patent number: 6756173
    Abstract: A toner and process for making the toner wherein each combined resin and colorant particle has an average size less than about 10 microns and wherein surface additive particles averaging less than about 40 nanometers in size average greater than two (2) percent of the combined weight of resin and colorant in the toner and wherein the Additive Adhesion Force Distribution percent value after 12 kilojoules of energy is greater than 40 percent.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: June 29, 2004
    Assignee: Xerox Corporation
    Inventor: James M. Proper
  • Patent number: 6753122
    Abstract: A toner for forming a color image comprises chromatic toners and a black toner is disclosed. Each of the toners is produced by polymerization of a polymerizable monomer in an aqueous medium, the difference of re-dispersion electro-conductivity of each of the toners is within the range of from 0.8 to 12 &mgr;s/cm, the number of free colorant particles on the black toner surface is less than 9 per 500 toner particles, and a light absorbance at 500 nm of a black toner dispersion is nor more than 0.08.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: June 22, 2004
    Assignee: Konica Corporation
    Inventors: Ken Ohmura, Ryuji Kitani, Yasuko Yamauchi, Kaori Soeda
  • Publication number: 20040115542
    Abstract: In a toner kit having i) a non-magnetic black toner having at least carbon black and ii) color toners, the black toner has a weight-average particle diameter represented by D4b and a one-point method BET specific surface area represented by Sb, and the color toners, other than the black toner, each have a weight-average particle diameter represented by D4c and a one-point method BET specific surface area represented by Sc, where the black toner and color toners satisfy the following relations (1) and (2):
    Type: Application
    Filed: October 1, 2003
    Publication date: June 17, 2004
    Inventors: Katsuyuki Nonaka, Yushi Mikuriya, Shinya Yachi, Shuntaro Watanabe
  • Publication number: 20040110079
    Abstract: An electrostastic latent image developing toner is disclosed. The toner comprises colored particles and an external additive, and in which the volume average particle diameter of the toner is 4.0-8.0 &mgr;m and the ratio of particles of at most 2.5 &mgr;m is 0.1-10 percent by volume. An image forming method employing the toner is also disclosed.
    Type: Application
    Filed: November 19, 2003
    Publication date: June 10, 2004
    Inventors: Asao Matsushima, Hiroshi Yamazaki, Michiaki Ishikawa
  • Publication number: 20040101776
    Abstract: An electrophotographic developer is provided for realizing high-quality images and superior reproducibility of laser dots in a low coverage region and reduced unevenness of color in halftone solid images. The electrophotographic developer includes a toner and a carrier. The toner has a shape factor of 140 or less and a volume average particle size distribution GSDv of 1.3 or less. The carrier has a coat resin layer on a core material, the coat resin layer containing a conductive powder. The core material has a dynamic electric resistivity of 1 &OHgr;·cm or less under an electric field of 104 V/cm in a form of a magnetic brush. The conductive powder has an electric resistivity of 101 &OHgr;·cm or greater and 106 &OHgr;·cm or less. The carrier has an electric resistivity in a range between 10 and 1×108 &OHgr;·cm. An image forming method is also provided wherein the electrophotographic developer is used for development in a developing stage.
    Type: Application
    Filed: June 27, 2003
    Publication date: May 27, 2004
    Applicant: Fuji Xerox Co., Ltd.
    Inventors: Kazuhiko Yanagida, Nobumasa Furuya, Takashi Yukutake
  • Patent number: 6740460
    Abstract: A dry toner for developing an electrostatic image, including a toner binder containing a urea-modified polyester. The toner has a volume average particle diameter Dv of 3 to 10 &mgr;m and a number average particle diameter Dp such that the ratio Dv/Dp of the volume average particle diameter to the number average particle diameter ranges from 1.05 to 1.25.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: May 25, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Shigeru Emoto, Hiroshi Yamasita, Tsunemi Sugiyama
  • Publication number: 20040058267
    Abstract: A toner for developing an electrostatic latent image is provided that is excellent in releasing property upon fixing and shape controllability upon production of the toner. The toner for developing electrostatic latent image has a number average molecular weight in a range of from 10,000 to 30,000 and a ratio of a Z average molecular weight and a weight average molecular weight in a range of from 3.0 to 6.0.
    Type: Application
    Filed: April 16, 2003
    Publication date: March 25, 2004
    Applicant: Fuji Xerox Co., Ltd.
    Inventors: Takao Ishiyama, Shuji Sato, Hiroshi Kamada, Masakazu Iijima
  • Publication number: 20040053154
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 &mgr;m to 7 &mgr;m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 &mgr;m to 2.0 &mgr;m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Application
    Filed: June 27, 2003
    Publication date: March 18, 2004
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 6706460
    Abstract: This invention relates to a latex composition comprising water as a continuous phase and, as the dispersed phase, hydrophobic polymer particles having associated therewith an infrared polymethine dye having covalently bonded thereto a phenylenediamine moiety. It further relates to a process for associating dye with polymer particles in a latex composition comprising the steps of: (1) forming a dye solution by dissolving a polymethine dye having covalently bonded thereto a phenylenediamine moiety in a water miscible or immiscible organic solvent; (2) forming a latex by dispersing hydrophobic polymer particles in an aqueous continuous phase; (3) blending the latex with the dye solution; and (4) loading of the polymer particles by removing the organic solvent, thereby forming a latex having the polymethine dye associated therewith.
    Type: Grant
    Filed: November 20, 2002
    Date of Patent: March 16, 2004
    Assignee: Eastman Kodak Company
    Inventors: Kevin W. Williams, Ruizheng Wang, Huijuan D. Chen
  • Patent number: 6703176
    Abstract: A toner contains at least a bonding resin and a coloring agent, and has a weight mean particle size from 5 &mgr;m to 12 &mgr;m; not less than 90% by number of particles not less than 3 &mgr;m have a circularity “a” not less than 0.900; a cut ratio Z and a weight mean size X of the toner are related as: cut ratio Z≦5.3×X; and a relationship of particles Y having a circularity of not less than 0.950 and a weight mean size X is Y≧e5.51×X−0.645 where X is 5 to 12 &mgr;m.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: March 9, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Naka, Yuichi Mizoo, Satoshi Matsunaga, Masami Azuma, Takashige Kasuya, Tadashi Dojo, Tsuneo Nakanishi, Nene Shibayama, Katsuhisa Yamazaki, Yusuke Hasegawa
  • Patent number: 6703177
    Abstract: An electrophotographic image forming method is disclosed. The method comprises forming a latent image on a static image carrier, developing the static image by a developer containing a toner, transferring the toner image onto another image carrier, transferring the toner image on the image carrier onto an image forming support, and fixing the toner image transferred on the image forming support, and the toner has a variation coefficient of the shape coefficient of not more than 16% and a number variation coefficient of the particle diameter distribution in number of not more than 27%, and the other image carrier is a cylindrical member having an electrode contacting to the interior surface thereof.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: March 9, 2004
    Assignee: Konica Corporation
    Inventors: Hiroshi Yamazaki, Ken Ohmura