Electrical Or Magnetic Parameter Patents (Class 430/111.41)
-
Publication number: 20100310982Abstract: A method for producing a carrier, including a step of periodically forming and discharging liquid droplets of a carrier core composition liquid from a plurality of nozzles formed in a thin film, using a liquid droplet forming unit having the thin film and a ring-shaped vibration generating unit disposed in a deformable area of the thin film so as to be along a circumference of the area and to vibrate the thin film, a step of forming carrier core particles by solidifying the discharged liquid droplets, and a step of coating the carrier core particles with a resin layer.Type: ApplicationFiled: December 18, 2008Publication date: December 9, 2010Inventors: Shinji Ohtani, Ryota Inoue, Yoshihiro Norikane
-
Publication number: 20100303506Abstract: A manufacturing apparatus provided with a rotary stirring section and a powder passage is used to manufacture the resin-layer coated carrier. At a fine resin particle adhering step, a magnetic base particle and a fine resin particle are inputted into the powder passage with the rotary stirring section rotating and the fine resin particle is adhered onto the surface of the magnetic base particle. At a spraying step, at least a liquid that plasticizes the fine resin particles is sprayed with spray gas from a spraying section on the magnetic base particle and the fine resin particle which are in a fluidized state in the powder passage. At a film-forming step, rotation by the rotary stirring section is continued to fluidize the magnetic base particles and the fine resin particles until the fine resin particles adhered to the magnetic base particles are softened to form a film.Type: ApplicationFiled: June 2, 2010Publication date: December 2, 2010Inventors: Takashi Hara, Yoshiaki Akazawa, Yoshitaka Kawase, Yoritaka Tsubaki, Yoshinori Mutoh, Keiichi Kikawa
-
Publication number: 20100279221Abstract: A resin-coated carrier is provided. A resin-coated carrier includes a carrier core and a resin coating layer formed on a surface of the carrier core. The carrier core is composed of a porous material having surface fine pores formed on a surface thereof, and has an apparent density of 1.6 to 2.0 g/cm3. The resin coating layer contains cross-linked fine resin particles. Additionally, the resin-coated carrier is configured such that a volume average particle size of the cross-linked fine resin particles contained in the resin coating layer and an area average diameter of the surface fine pores satisfy a predetermined relational expression.Type: ApplicationFiled: April 28, 2010Publication date: November 4, 2010Inventors: Osamu Wada, Takanori Kamoto, Nobuyuki Yoshioka, Ayae Nagaoka, Tadashi Iwamatsu
-
Patent number: 7824833Abstract: A spherical resin-coated ferrite carrier for an electrophotographic developer which can maintain a stable resistance and chargeability, a favorable charge rising property because of an excellent fluidity, and has a suitable durability, its production method which is excellent in economic efficiency and production stability, and an electrophotographic developer using the resin-coated ferrite carrier, are provided. A resin-coated ferrite carrier for an electrophotographic developer which is a spherical resin-coated ferrite carrier, wherein a carrier core material thereof has an irregular surface to improve the adhesive strength to a resin coat, and wherein the irregularity of the surface takes a finely streaked wrinkle pattern, its production method, and an electrophotographic developer using the resin-coated ferrite carrier, are employed.Type: GrantFiled: November 30, 2006Date of Patent: November 2, 2010Assignee: Powdertech Co., Ltd.Inventors: Kanao Kayamoto, Issei Shinmura, Toshio Honjo
-
Publication number: 20100248126Abstract: A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 35.0?L*?45.0 and 60.0?C*?72.0; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: June 9, 2010Publication date: September 30, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Publication number: 20100239324Abstract: A system and method for producing toner associated with a selectable gloss level is provided. The method includes holding a first toner formed of particles, associated with a relatively low gloss level, and having two particle properties, each having a first and second characteristic, respectively, and holding a second toner formed of particles, associated with a relatively high gloss level, and having the two particle properties, each having a third and fourth characteristic, respectively. The first and third and the second and fourth characteristics are substantially the same. The first and second toners are transported and a ratio of their respective volumes is determined so that when blended a third toner is produced which is associated with a selected gloss level that is in-between the low and high gloss levels. The transporting is controlled in accordance with the determined ratio.Type: ApplicationFiled: March 20, 2009Publication date: September 23, 2010Applicant: Xerox CorporationInventors: James A. Winters, Kip L. Jugle
-
Patent number: 7794908Abstract: Provided is magnetic toner including capsule type toner particles each having a surface layer (B) on a surface of a toner base particle (A) containing at least a binder resin (a) mainly formed of a polyester, a magnetic substance, and a wax, in which, the surface layer (B) includes a resin (b), and the resin (b) includes a resin selected from the group consisting of a polyester resin (b1), a vinyl resin (b2), and a urethane resin (b3); a glass transition temperature Tg(a) of the binder resin (a) and a glass transition temperature Tg(b) of the resin (b) satisfy a relationship of Tg(a)<Tg(b); a magnetization (?t) in an external magnetic field of 79.6 kA/m of the magnetic toner is 12 Am2/kg or more and 30 Am2/kg or less; and an average circularity of the toner is 0.960 or more and 1.000 or less.Type: GrantFiled: March 2, 2009Date of Patent: September 14, 2010Assignee: Canon Kabushiki KaishaInventors: Takaaki Kaya, Shigeto Tamura, Ryoichi Fujita, Makoto Kambayashi, Takeshi Ikeda
-
Publication number: 20100216066Abstract: A transparent toner for electrostatic latent image developing, including a binder resin and a release agent, the difference between Tm and Tc being from about 30° C. to about 50° C., wherein Tm is an endothermic peak temperature of the release agent determined in a temperature rising process and Tc is an exothermic peak temperature of the release agent determined in a temperature decreasing process, in a measurement by a differential scanning calorimeter (DSC) according an ASTM method, and the toner having a weight average molecular weight of from about 35,000 to about 70,000.Type: ApplicationFiled: September 25, 2009Publication date: August 26, 2010Applicant: FUJI XEROX CO., LTD.Inventors: Yasuo Kadokura, Atsushi Sugawara, Masaru Takahashi, Yusuke Ikeda, Masanobu Ninomiya
-
Publication number: 20100203438Abstract: A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0?L*?95.0 and 100.0?C*?115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: March 3, 2010Publication date: August 12, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Patent number: 7767370Abstract: A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the magenta toner determined in a powder state satisfy the relationships of 35?L*?45 and 60?C*?72; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: GrantFiled: July 29, 2008Date of Patent: August 3, 2010Assignee: Canon Kabushiki KaishaInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Publication number: 20100190101Abstract: There is provided a technique capable of reducing a transfer residual ratio of a toner to an image carrier. A developer includes a magnetic particle, and a toner particle charged by the magnetic particle, and when a relation between an adhesion force F of the toner particle to an image carrier of an image forming apparatus and a square of a charge amount q of the toner particle is represented by a linear function approximate expression of F=K×q2+F0 based on a particle size distribution of the toner particle, a value of a proportional constant K of the square of the charge amount q of the toner particle and a value of a non-electrostatic adhesion force F0 satisfy a specified relation.Type: ApplicationFiled: January 28, 2010Publication date: July 29, 2010Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHAInventor: Shoko Shimmura
-
Publication number: 20100183971Abstract: A magnetic carrier having magnetic carrier particles each containing at least a magnetic core particle and a resin; the magnetic carrier having a resistivity of from 1.0×106 ?·cm or more to 1.0×1010 ?·cm or less at an electric-field intensity of 1.0×103 V/cm as found by measuring dynamic impedance; electric-field intensity E(109) at which the resistivity of the magnetic carrier comes to 1.0×109 ?·cm being 2.0×104 V/cm or less, and electric-field intensity E(108) at which the resistivity of the magnetic carrier comes to 1.0×108 ?·cm being from 5.0×103 V/cm or more to 2.8×104 V/cm or less; and the electric-field intensity E(108) and the electric-field intensity E(109) being in a ratio, E(108)/E(109), of from 1.0 or more to 5.0 or less.Type: ApplicationFiled: January 21, 2010Publication date: July 22, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Hiroyuki Fujikawa, Koh Ishigami, Kunihiko Nakamura, Nozomu Komatsu, Yoshinobu Baba, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Publication number: 20100183968Abstract: The invention provides a transparent toner for developing an electrostatic latent image, including a binder resin and a release agent, the difference between the endothermic peak Tm of the release agent in a temperature increasing process and the exothermic peak Tc of the release agent in a temperature decreasing process being from about 10° C. to about 50° C., where Tm and Tc are measured with a differential scanning calorimeter (DSC) according to the ASTM method.Type: ApplicationFiled: October 13, 2009Publication date: July 22, 2010Applicant: Fuji Xerox Co., Ltd.Inventors: Atsushi SUGAWARA, Masaru TAKAHASHI, Yasuo KADOKURA, Masanobu NINOMIYA
-
Patent number: 7759040Abstract: A cleaner-less image forming method includes forming an electrostatic latent image on a electrostatic latent image carrying member; developing the electrostatic latent image with a developer comprising a toner and a carrier to form a toner image; and transferring the toner image. The carrier has a median of an arithmetic average height distribution of from 0.45 to 0.65 ?m, and the toner includes an external additive and has an average circularity of 0.975 or more.Type: GrantFiled: October 13, 2004Date of Patent: July 20, 2010Assignee: Fuji Xerox Co., Ltd.Inventors: Noriyuki Mizutani, Yuusaku Shibuya, Masanobu Ninomiya, Toshiyuki Yano
-
Publication number: 20100178603Abstract: The invention provides a developer for developing an electrostatic latent image, the developer having at least: a transparent toner; and a carrier. The carrier contains at least: a magnetic particle; and a resin coating layer. The resin coating layer coats the surface of the magnetic particle and has cyan color. The invention further provides a developer cartridge storing the developer. The invention further provides a process cartridge storing the developer. The invention further provides an image formation apparatus having at least a color toner image-forming unit, a transparent toner image-forming unit that uses the developer to form a transparent toner image, and a fixing unit.Type: ApplicationFiled: August 21, 2009Publication date: July 15, 2010Applicant: FUJI XEROX CO., LTD.Inventors: Akira MATSUMOTO, Yukiaki NAKAMURA
-
Publication number: 20100159380Abstract: A two-component developer containing a cyan toner and a magnetic carrier, wherein the cyan toner has the characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.0; and (iii) the absolute value for the triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.Type: ApplicationFiled: March 3, 2010Publication date: June 24, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Publication number: 20100143833Abstract: A magnetic carrier is provided which uses a toner having high coloring power and enables development to be performed at low electric field intensity and can form high quality images while keeping gradation characteristics. The magnetic carrier includes magnetic carrier particles including at least porous magnetic core particles and a resin. The electric field intensity just before the break-down of the magnetic carrier is 1,300 V/cm or more and 5,000 V/cm or less.Type: ApplicationFiled: January 21, 2010Publication date: June 10, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Yoshinobu Baba, Koh Ishigami, Tomoko Endo, Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Chika Inoue, Takayuki Itakura
-
Publication number: 20100135700Abstract: A developer of the present invention includes a toner and a carrier. The toner contains a charge control agent, and the carrier has on its surface a coating layer to which a charge control agent and electrically conductive particles are added. All of constituent elements of one of the charge control agent of the toner and the charge control agent of the carrier are contained in constituent elements of the other one of the charge control agents. With the configuration, the developer of the present invention is capable of stably maintaining a toner charge amount and outputting high-quality images for long periods.Type: ApplicationFiled: March 26, 2008Publication date: June 3, 2010Applicant: SHARP KABUSHIKI KAISHAInventors: Yoshinori Mutoh, Tadashi Iwamatsu, Takanori Kamoto, Nobuyuki Yoshioka, Hiroyuki Hirakawa, Takashi Hara
-
Publication number: 20100129751Abstract: A process for the manufacture of a toner comprising toner particles which comprise at least resin and colorant, the process comprising the steps of: providing a mixed dispersion of at least primary resin particles and primary colorant particles stabilised by two or more surfactants in a liquid medium, the surfactants comprising at least a first ionic surfactant and a second ionic surfactant of the same polarity as the first ionic surfactant, wherein the first and second ionic surfactants have different linear chain lengths; and causing the primary particles to associate.Type: ApplicationFiled: April 29, 2008Publication date: May 27, 2010Inventors: Daniel Patrick Morris, Martin Russell Edwards, Mohammed Nawaz, Simon Pickard
-
Publication number: 20100124714Abstract: A developing agent is used for a recycle type image forming apparatus including an image bearing body on which an electrostatic latent image is developed with the developing agent and an image transferred to a transfer medium is formed, and includes a toner particle, a magnetic carrier to charge the toner particle to a specified polarity, and a circulation agent which is charged to a polarity reverse to that of the toner particle in the developing agent, has a primary particle diameter of 20 to 100 ?m, has a magnetization lower than that of the magnetic carrier, and has a transfer efficiency of 0 to 10% from the image bearing body to the transfer medium.Type: ApplicationFiled: November 17, 2009Publication date: May 20, 2010Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHAInventor: Hiroshi Kawaguchi
-
Patent number: 7682764Abstract: A resin coated carrier for electrophotography and a two-component developer for electrophotography made therefrom, in which electrostatic charge giving ability to toner is high, anti-spent property is superior, charging property is stable even if a large number sheets are continuously printed, initial electrostatic charge increasing ability and electrostatic charge maintaining ability after leaving are also superior, and fogging at supplying toner and fogging after leaving are not generated. In a resin coated carrier for electrophotography comprising a coating material and a core material, in which the coating material covers the surface of the core material, the coating material contains a resin component and a conductive agent, the core material is ferrite, and electric resistance of the carrier at an applied voltage of 100 V set to be 1.0×103 to 1.0×106 ?·cm, or breakdown voltage is set to be 120 to 280 V.Type: GrantFiled: April 19, 2005Date of Patent: March 23, 2010Assignee: Tomoegawa Paper Co., LtdInventors: Akira Fujiwara, Yoshiaki Harada
-
Patent number: 7678523Abstract: To provide a magnetic toner which has superior low-temperature fixing performance and pressure roller anti-staining properties even in various forms of use, has been kept from image defects such as image non-uniformity even during long-time image reproduction and can achieve high-level image quality. In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the activation energy Ea (kJ/mol) that is determined from a shift factor aT120 in a master curve of the toner, prepared when 120° C. is set as reference temperature, and the activation energy Eb (kJ/mol) that is determined from a shift factor aT150 in a master curve of the toner, prepared when 150° C. is set as reference temperature, satisfy Expression (1), and the Ea is 110 kJ/mol or less: 1.00?Ea/Eb<1.20??(1).Type: GrantFiled: December 9, 2008Date of Patent: March 16, 2010Assignee: Canon Kabushiki KaishaInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara
-
Patent number: 7678524Abstract: A magnetic toner including at least: a binder resin; and a magnetic body, in which, when magnetization at a magnetic field strength of 397.9 kA/m and a coercive force of the magnetic toner are denoted by ?s (Am2/kg) and Hc (kA/m), respectively, a magnetic field strength at which the magnetic toner shows a magnetization value equal to 95% of ?s is denoted by H95% (kA/m), and a number average particle size of the magnetic body is denoted by d (?m), H95%, Hc, and d satisfy the following expressions. 151<H95%<200??(1) 7.Type: GrantFiled: May 3, 2006Date of Patent: March 16, 2010Assignee: Canon Kabushiki KaishaInventors: Yusuke Hasegawa, Yoshihiro Ogawa, Junko Nishiyama, Miho Okazaki, Takashige Kasuya, Tomohisa Sano
-
Publication number: 20100062360Abstract: Methods of making ink toners for use in electrostatic imaging are disclosed.Type: ApplicationFiled: July 25, 2006Publication date: March 11, 2010Inventor: Gal Victor
-
Publication number: 20100015421Abstract: When color images are printed on a substantially transparent substrate, such as a transparency film, or on a highly colored substrate, the color properties of image may be compromised. When color images are printed on a substantially transparent substrate, the images do not have the maximum possible color saturation because a large portion of the incident light is not reflected back. As a result, images appear to be dull and lower in contrast. When color images are printed on highly colored substrates, the color properties of the image are also influenced by the color of the substrate. In order to enable printing on such substrates, an opaque toner was developed which comprises predispersed inorganic filler with a refractive index of greater than 1.75.Type: ApplicationFiled: May 29, 2009Publication date: January 21, 2010Inventors: Dinesh Tyagi, Louise Granica
-
Publication number: 20090325098Abstract: A toner including stabilized magnetic single-crystal nanoparticles, wherein the value of the magnetic anisotropy of the magnetic nanoparticles is greater than or equal to 2×104 J/m3. The magnetic nanoparticle may be a ferromagnetic nanoparticle, such as FePt. The toner includes a magnetic material that minimizes the size of the particle, resulting in excellent magnetic pigment dispersion and dispersion stability, particularly in emulsion/aggregation toner processes. The smaller sized magnetic particles of the toner also maintains excellent magnetic properties, thereby reducing the amount of magnetic particle loading required in the toner.Type: ApplicationFiled: June 26, 2008Publication date: December 31, 2009Applicant: XEROX CORPORATIONInventors: Richard P.N. VEREGIN, Karen A. MOFFAT, Marcel P. BRETON, Peter M. KAZMAIER, Patricia A. BURNS, Paul F. SMITH
-
Publication number: 20090317737Abstract: A color toner is provided which has a dielectric strength equal to or lower than that of a black toner containing carbon black, and which has an improved charging rate and charge stability against changes in the environment.Type: ApplicationFiled: April 10, 2009Publication date: December 24, 2009Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Hisao Okada, Mitsuru Oikawa
-
Patent number: 7604915Abstract: Use of a charge control agent in a toner, such as a magenta toner, to give an increased triboelectric charge is disclosed. The magenta toner may contain a magenta resin, such as xanthene.Type: GrantFiled: August 23, 2006Date of Patent: October 20, 2009Assignee: Xerox CorporationInventors: Joo T. Chung, Scott M. Silence, Julia Kohlmeier, John Ianni
-
Patent number: 7601475Abstract: A two-component developing agent containing a carrier which can maintain a charge-imparting property to a toner at a high level for a long period of time, does not generate flying of the carrier and can correspond to an image forming apparatus of present day having a long operation life and can form a high-quality image having high image density and sharpness, is provided. In the two-component developing agent containing a carrier in which a resin coating layer is formed on a surface of a core material, and a toner, in which an X-ray intensity of an alumina particle by a fluorescent X-ray analysis, the amount of the alumina particle to be used to the resin coating layer is adjusted such that it comes to be smaller than the X-ray intensity by the fluorescent X-ray analysis of a metal contained in a largest amount in the core material.Type: GrantFiled: September 12, 2006Date of Patent: October 13, 2009Assignee: Sharp Kabushiki KaishaInventors: Takeshi Katoh, Toshihisa Ishida, Yoshinori Urata, Kazuya Korematu, Takeshi Takayama, Mitsuhiro Hasegawa
-
Patent number: 7592115Abstract: A carrier for electrostatic latent image developer, including a core material and at least two or more resin-coated layers formed on the surface of the core material, wherein the resin-coated layers include a siloxane bond-containing coating resin containing an organic metal compound and a conductive material, the metal contained in the organic metal compound in the innermost resin-coated layer has an ionization potential of less than 7 eV, and the metal contained in the organic metal compound in the outermost resin-coated layer has an ionization potential of 7 eV or more.Type: GrantFiled: October 14, 2005Date of Patent: September 22, 2009Assignee: Fuji Xerox Co., Ltd.Inventors: Yasushige Nakamura, Sadaaki Yoshida
-
Patent number: 7592116Abstract: The object of the present invention is to provide a carrier for electrophotography which includes a core material and a coating layer comprising particles on a surface of the core material, in which the carrier for electrophotography comprises indium (In) in an amount of 0.0001% by mass to 0.5% by mass. The present invention also provides a developer using the carrier, a developer container, an image forming method, an image forming apparatus, and a process cartridge in each of which the carrier is used.Type: GrantFiled: November 10, 2005Date of Patent: September 22, 2009Assignee: Ricoh Company, Ltd.Inventors: Kousuke Suzuki, Tomio Kondou, Shinichiro Yagi, Hitoshi Iwatsuki
-
Patent number: 7572565Abstract: Carrier includes a mixture of carrier particles. The mixture may contain first carrier particles containing carrier cores that are coated with a polymer coating, the coating containing polymer and conductive particles, and second carrier particles containing carrier cores that are not coated with a polymer coating. The mixture may contain carrier particles having a conductivity of at least about 5×10?8 (ohm-cm)?1 and carrier particles having a conductivity of less than about 1×10?8 (ohm-cm)?1.Type: GrantFiled: April 12, 2006Date of Patent: August 11, 2009Assignee: Xerox CorporationInventors: Eugene F. Young, Thomas C. Dombroski, Deepak R. Maniar, Mark S. Jackson
-
Publication number: 20090197190Abstract: An object of the present invention is to suppress the adhesion of a carrier to an image bearing member and the generation of a flaw in the surface layer of the image bearing member, and to improve the dot reproducibility of an electrostatic latent image, and soon. The object is achieved by a two-component developer containing a magnetic carrier, which contains resin-containing magnetic particles, in which the packed bulk density ?1 is 0.80 to 2.40 and ?1/?2 (?2 represents true density) is 0.20 to 0.42 of the porous magnetic core particles, and a specific resistance of the porous magnetic core particles, an average breaking strength of the magnetic carrier and a toner surface tension constant in a 45-vol % aqueous solution of methanol measured by a capillary suction time method fall into the specific range, respectively.Type: ApplicationFiled: May 15, 2008Publication date: August 6, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Kunihiko Nakamura, Hiroyuki Fujikawa, Nozomu Komatsu, Yoshinobu Baba, Takayuki Itakura
-
Patent number: 7537874Abstract: A toner having a high strength magnetite in an amount of from about 10 to about 40 weight percent, wherein the magnetite includes a material selected from the group consisting of FeO, Fe2O3, Fe3O4, gamma iron oxides, cobalt-gamma iron oxides, and mixtures thereof, and further including a developer having a carrier and toner as just described.Type: GrantFiled: February 21, 2006Date of Patent: May 26, 2009Assignee: Xerox CorporationInventors: Mark E. Mang, Hui Chang, Michael L. Grande, Gary A. Minagawa
-
Publication number: 20090117477Abstract: To solve a thin image density and sweeping occurring when a toner carrying member having a small diameter is used, provided is an image-forming method including: a charging step; an electrostatic latent image-forming step; a developing step; a transferring step; and a fixing step, in which a magnetic toner to be used in the method has a specific weight average particle diameter (D4); the magnetic toner has a specific intensity of magnetization in a specific magnetic field; and a surface free energy of a surface of the magnetic toner and a surface free energy of a surface of a toner carrying member to be used in the method satisfy specific relationships.Type: ApplicationFiled: October 29, 2008Publication date: May 7, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko
-
Publication number: 20090029279Abstract: A toner is provided which is capable of preventing a decrease in a toner charge amount and thus preventing fog and a decrease in image density even in a case where images of low coverage are continuously printed or where a printing operation restarts immediately after long suspension of operation in an image forming apparatus. The toner contains coloring resin particles formed of a boron compound, a hinder resin, and a colorant, and an external additive of which a primary particle is adjusted to have a size of 16 nm or more and 30 nm or less and of which a volume resistivity is adjusted to 1×1012 ?·cm or more and 5×1015 ?·cm or less.Type: ApplicationFiled: July 15, 2008Publication date: January 29, 2009Inventors: Takamichi Mori, Takeshi Katoh, Takeshi Tsukiyama
-
Patent number: 7468233Abstract: Electro-photographic images having high picture quality and low carrier adhesion can be obtained using a two-component developer containing a carrier containing (A) a carrier containing a core containing a magnetic material, the core being coated with at least one resin layer; and (B) a toner; wherein the carrier has a weight average particle diameter Dw of 22-32 ?m; wherein a content of carrier particles having a diameter smaller than 20 ?m is 0-7% by weight based on the weight of the carrier; wherein a content of carrier particles having a diameter smaller than 36 ?m is 90-100% by weight based on the weight of the carrier; wherein a weight average particle diameter Dw of the toner is 2-7 ?m; and wherein a ratio Dw/Dn of the weight average particle diameter of the toner to the number average particle diameter of the toner is 1.00-1.25.Type: GrantFiled: September 12, 2005Date of Patent: December 23, 2008Assignee: Ricoh Company, Ltd.Inventors: Masashi Nagayama, Kimitoshi Yamaguchi, Naoki Imahashi
-
Publication number: 20080286668Abstract: An object of the present invention is to provide a two-component developer which can achieve a high-definition image with a smaller toner laid-on level than a conventional one, provides a color gamut comparable to that of printing, can respond to an increase in printing speed, and allows an image with a stable tinge to be formed even in long-term use. The object can be achieved by a two-component developer containing a cyan toner and a magnetic carrier, the two-component developer being characterized in that the cyan toner has the following characteristics: (i) when the concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and the absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the relationship of 2.00<A712/Cc<8.15; (ii) the lightness L* and chroma C* of the cyan toner determined in a powder state satisfy the relationships of 25.0?L*?40.0 and 50.0?C*?60.Type: ApplicationFiled: July 29, 2008Publication date: November 20, 2008Applicant: CANON KABUSHIKI KAISHAInventors: Koh Ishigami, Kazuo Terauchi, Noriyoshi Umeda, Tetsuya Ida, Naoki Okamoto, Yojiro Hotta, Yoshinobu Baba, Takayuki Itakura, Takeshi Yamamoto, Manami Haraguchi, Kenta Kubo
-
Patent number: 7439003Abstract: A magnetic black toner for electrophotography comprising a binding resin, a magnetic substance, and a pigment, wherein the pigment is at least one of phthalocyanine pigment and Mn containing hematite, and the content ratio of the magnetic substance and the pigment in the toner satisfy the following formulae: 10?A?30, 0.1?B?3, 5?C?40, wherein A denotes the content ratio (mass %) of the magnetic substance in the toner, B denotes the content ratio (mass %) of the phthalocyanine pigment in the toner, and C denotes the content ratio (mass %) of the Mn containing hematite in the toner.Type: GrantFiled: May 25, 2005Date of Patent: October 21, 2008Assignee: Fuji Xerox Co., Ltd.Inventors: Seijirou Ishimaru, Sadaaki Yoshida, Yoshimichi Katagiri, Masahisa Ochiai
-
Patent number: 7422832Abstract: Provided is a magnetic toner comprising magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide, the magnetic toner being excellent in developability and environmental stability, and being capable of reducing a toner consumption. A saturation magnetization ?s and a remanent magnetization ?r of the magnetic toner in a measured magnetic field of 795.8 kA/m are arranged in the range of 5 to 60 Am2/kg and in the range of 0.1 to 10.0 Am2/kg, respectively, and the binder resin having a polyester component polymerized by using a Ti chelate compound as a catalyst is used.Type: GrantFiled: February 26, 2004Date of Patent: September 9, 2008Assignee: Canon Kabushiki KaishaInventors: Yoshihiro Ogawa, Takashige Kasuya, Syuhei Moribe, Kouji Nishikawa
-
Patent number: 7422833Abstract: A charge control resin composition for positive or negative charge, which is prepared either by mixing and kneading a charge control resin for positive or negative charge with a colorant, or by mixing and kneading the above combination further with a charge control resin for opposite charge or a charge control resin composition for opposite charge; wherein colorant particles are finely dispersed as desired. The resultant mixture is mixed with a polymerizable monomer to obtain polymerizable monomer composition. Then, the polymerizable monomer composition is dispersed or emulsified in an aqueous dispersion medium containing a dispersion stabilizer, and polymerized to obtain a toner.Type: GrantFiled: September 27, 2001Date of Patent: September 9, 2008Assignee: Zeon CorporationInventors: Kazu Niwa, Fuminari Oyama
-
Patent number: 7399567Abstract: A toner for electrostatic latent image development containing at least a binder resin and a colorant, wherein [Fe]/[C] satisfies the following formula (1) where [C] indicates the carbon content (%) and [Fe] indicates the iron content (%) of the toner determined through X-ray fluorescence analysis, 0.00005?[Fe]/[C]?0.0002.Type: GrantFiled: June 10, 2005Date of Patent: July 15, 2008Assignee: Fuji Xerox Co., Ltd.Inventors: Yasuo Kadokura, Masakazu Iijima, Tomohito Nakajima, Satoshi Yoshida, Michio Take, Takao Ishiyama
-
Patent number: 7390603Abstract: The present invention provides An image forming apparatus having: a negatively chargeable spherical toner; an latent image carrier; a charging member for charging a surface of the latent image carrier uniformly without contacting the latent image carrier; an electrostatic latent image forming member for forming an electrostatic latent image on the surface of the latent image carrier; a developing member for developing the electrostatic latent image, without contacting the latent image carrier, by using the negatively chargeable spherical toner so as to form a toner image on the latent image carrier; and an intermediate transfer medium to which the toner image is transferred, wherein the negatively chargeable spherical toner haves: a toner mother particle having a binder resin and a colorant; and a hydrophobic alumina particle as an external additive, wherein the hydrophobic alumina particle has a work function (?A1) larger than a work function (?TM) of a surface of the intermediate transfer medium.Type: GrantFiled: June 24, 2005Date of Patent: June 24, 2008Assignee: Seiko Epson CorporationInventors: Nobuhiro Miyakawa, Toshiaki Yamagami, Satoshi Chiba
-
Patent number: 7390604Abstract: The present invention provides a negatively chargeable spherical toner having: a toner mother particle having a binder resin and a colorant, which has: a number average particle size of from 4.5 to 9 ?m; a particle size distribution that has an integrated value of particle sizes of 3 ?m or less of 1% or less; and an average sphericity of from 0.95 to 0.99; and an alumina fine particle externally added to the toner mother particle, which has a number average particle size of from 0.1 to 1.0 ?m, wherein a work function (?t) of the toner mother particle is larger than a work function (?A) of the alumina fine particle by at least 0.4 eV.Type: GrantFiled: January 20, 2006Date of Patent: June 24, 2008Assignee: Seiko Epson CorporationInventors: Nobuhiro Miyakawa, Toshiaki Yamagami, Ken Ikuma
-
Patent number: 7384719Abstract: A carrier composition, including a particulate magnetic material; and a layer located on a surface of the particulate magnetic material, wherein the layer is formed by heating a mixture containing a metal alkoxide; a resin having a hydroxyl group reacting with the metal alkoxide; and a particulate inorganic material.Type: GrantFiled: March 2, 2005Date of Patent: June 10, 2008Assignee: Ricoh Company Ltd.Inventors: Masahide Yamashita, Tomio Kondou, Kousuke Suzuki
-
Patent number: 7378211Abstract: A carrier composition having magnetite with a diameter of from about 80 microns to about 150 microns, and wherein the carrier has a conductivity of from about 10?8 to about 10?11 (ohms-cm)?1 and a carrier breakdown voltage of from about 20 to about 200 volts, and a developer composition with toner and this carrier composition, and also including a developer housing apparatus and an electrostatographic apparatus comprising the developer housing apparatus.Type: GrantFiled: August 15, 2005Date of Patent: May 27, 2008Assignee: Xerox CorporationInventors: Padam K. Angra, Michael L. Grande, Zhaoyi M. Masucci, Joseph H. Rowe, John S. Walters
-
Patent number: 7358019Abstract: The present invention provides a developing process including the steps of charging toner particles supported on a developer carrier; and providing the charged toner particles to an electrostatic latent image formed on an image carrier, wherein, the charged toner particles satisfy formulas (1) and (2) shown below, when being measured by the laser doppler method in an oscillation field in an acoustic alleviation cell to determine individual particle size and charged amount thereof: k1=(B2?B1)/(A1?A2)<???(1) B2<0??(2) wherein A1 [?m] and B1 [fC] represent the particle size and the charged amount of the charged toner particle in the division that has the largest number proportion in the distribution divided by the measured particle size and the measured charged amount, respectively; A2 [?m] represents the particle size in the division that has the smallest particle size in the particle size distribution, provided that the number proportion of the division is 1% or more; and B2 [fC] represents the chargeType: GrantFiled: August 17, 2004Date of Patent: April 15, 2008Assignee: Seiko Epson CorporationInventors: Hiroshi Toyama, Ken Ikuma
-
Patent number: 7344814Abstract: A toner for an image-forming apparatus and method which apparatus has a cleaning means with a cleaning blade to remove a residual toner remaining on a surface of a photoconductive member after transfer; the toner being a mixture of a colored polymer particle and an external additive. The colored polymer particle has an average circle degree in the range of 0.95-0.995 and a volume average particle diameter in the range of 3-8 ?m. The toner has an absolute value of charge amount in the range of 20-70 ?C/g in a toner layer formed on a developing roll when the toner is used with the image-forming apparatus.Type: GrantFiled: November 26, 2003Date of Patent: March 18, 2008Assignee: Zeon CorporationInventor: Muneharu Itoh
-
Publication number: 20080056769Abstract: An electrostatic image developing carrier including at least a core material and a coating resin layer which coats the surface of the core material, the resin layer comprising a thermoplastic resin having an alicyclic group, a thermal reduction in accordance with the TGA method being in the range of 0.5 weight % to 5 weight % of the whole of the carrier in the range of 100° C. to 400° C., and further an endothermic quantity of the whole of the carrier in accordance with the DTA method is in the range of 7 mJ/g to 40 mJ/g in the range of 100° C. to 400° C.Type: ApplicationFiled: April 4, 2007Publication date: March 6, 2008Applicant: FUJI XEROX CO., LTD.Inventors: Akihiro Iizuka, Fusako Kiyono, Tsuyoshi Murakami
-
Publication number: 20080050668Abstract: Use of a charge control agent in a toner, such as a magenta toner, to give an increased triboelectric charge is disclosed. The magenta toner may contain a magenta resin, such as xanthene.Type: ApplicationFiled: August 23, 2006Publication date: February 28, 2008Applicant: Xerox CorporationInventors: Joo T. Chung, Scott M. Silence, Julia Kohlmeier, John Ianni