Patents Examined by Roland Martin
  • Photoconductor with charge generation binder blend
    Patent number: 6042980
    Abstract: Charge generation layers for photoconductors comprise a binder and a charge generation compound, wherein the binder comprises a blend of polyvinylbutyral polymer and at least one resin which improves at least one electrical characteristic of a photoconductor in which the charge generation layer is included. Photoconductors comprise the charge generation layer in combination with a substrate and a charge transport layer.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: March 28, 2000
    Assignee: Lexmark Internatonal, Inc.
    Inventors: Laura Lee Kierstein, Kasturi Rangan Srinivasan
  • Toner for developer of electrostatic latent image, method for producing toner for developer of electrostatic latent image, developer of electrostatic latent image and method for forming image
    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
  • Image forming method and image supporting material
    Patent number: 6042984
    Abstract: An image forming method and an image supporting material are provided. An image is formed on a transfer layer of an image transfer material and transferred onto an image receiving material together with at least one part of the transfer layer, and then a transparent resin layer is formed on at least one part of the image transferred on the image receiving material to prepare the image supporting material.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: March 28, 2000
    Assignee: Ricoh Company, Ltd.
    Inventor: Keishi Taniguchi
  • Electrophotographic toner, electrophotographic developer, and image forming method
    Patent number: 6040104
    Abstract: An electrophotographic toner containing a binding resin and a coloring agent, wherein as the binding resin, a resin is included in which the minimum value of tan .delta. of the binding resin exists between the glass transition temperature (Tg) and a temperature at which the loss modulus (G") is 1.times.10.sup.4 Pa, the minimum value of tan .delta. is less than 1.2, the storage modulus (G') at a temperature wherein tan .delta. is minimum is 5.times.10.sup.5 Pa or more, and the value of tan .delta. is 3.0 or more at a temperature wherein G"=1.times.10.sup.4 Pa. Further, a vinyl-based resin can be added in a small amount to the polyester resin having these features to provide a mixture to be used. Further, image formation is conducted using a transfer material in which the same resin is also used in an image-receiving layer.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: March 21, 2000
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masaki Nakamura, Satoshi Yoshida
  • Porous photoreceptor and method for manufacturing the same
    Patent number: 6040106
    Abstract: A method for manufacturing a photoreceptor includes the steps of consecutively forming a transparent conductive layer, a photoconductive layer, insulation layer and an electrode layer on a transparent support member, covering the electrode layer with a photo-setting dry film having a mask pattern therein, and sand-blasting the electrode layer and the insulation layer through the mask pattern to form an array of pores in the electrode layer and the insulation layer. A porous layer having a uniform thickness and uniform arrangement of pores can be obtained.
    Type: Grant
    Filed: March 15, 1999
    Date of Patent: March 21, 2000
    Assignee: NEC Corporation
    Inventors: Takeshi Hori, Tsutomu Uezono, Tomoyuki Yoshii, Yasuhiro Funayama
  • Toner for developing electrostatic image and image forming method
    Patent number: 6040103
    Abstract: A toner for developing an electrostatic image is composed of toner particles each containing at least a binder resin, a colorant, and a wax. The wax satisfies conditions of:(a) showing a maximum heat-absorption peak in a region of 50-130.degree. C. on temperature increase on a DSC (differential scanning calorimeter) curve, and(b) giving a .sup.13 C-NMR (nuclear magnetic resonance) spectrum showing a total peak area S in a range of 0-50 ppm, a total peak area S1 in a range of 36-42 ppm and a total peak area S2 in a range of 10-17 ppm satisfying:1.0.ltoreq.(S1/S).times.100.ltoreq.10, 1.5.ltoreq.(S2/S).times.100.ltoreq.15, and S1<S2.The wax satisfying the above-conditions has an appropriately branched long-chain structure and provides the toner with a good balance of good low-temperature fixability and anti-hot-temperature offset characteristic.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: March 21, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Manabu Ohno, Takeshi Ohtake, Satoshi Matsunaga, Tadashi Doujo
  • Carrier with ferrocene containing polymer
    Patent number: 6037091
    Abstract: A carrier comprised of a core and thereover a ferrocene containing polymer.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: March 14, 2000
    Assignee: Xerox Corporation
    Inventors: Paula J. MacLeod, Richard P. N. Veregin, Charles H. Honeyman
  • Electrophotographic photoconductor and method for producing same
    Patent number: 6037089
    Abstract: An electrophotographic photoconductor and method for producing same, the electrophotographic photoconductor including an electroconductive substrate; and a photosensitive film laminated on said electroconductive substrate, wherein the electroconductive substrate comprises an aluminum substrate which has an anodic oxidation film on at least one surface thereof and which has been treated with a sealing agent mixture including an additive selected from the group consisting of a phosphate ester surfactant, a naphthalene sulfonate formaldehyde condensate, and a bisphenol A sulfonate formaldehyde condensate and a sealing agent.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: March 14, 2000
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Hidetaka Yahagi, Yukihisa Tamura, Masaaki Sakaguchi, Yutaka Nakagishi
  • Process for producing polymerized toner
    Patent number: 6033822
    Abstract: Disclosed herein are a polymerized toner of core-shell structure, comprising core particles composed of colored polymer particles having a volume average particle diameter (dv) of 0.5-20 .mu.m and a ratio (dv/dp) of the volume average particle diameter (dv) to a number average particle diameter (dp) of at most 1.7, and shell which is formed of a polymer layer having an average film thickness of 0.001-0.1 .mu.m and covers each of the core particles, and a production process thereof.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: March 7, 2000
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Jun Hasegawa, Tokudai Ogawa, Jun Sakai, Takahiro Takasaki, Noboru Yanagida
  • Developing device for an image forming apparatus
    Patent number: 6033818
    Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: March 7, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihiro Sugiyama, Kazuhiro Yuasa, Shuichi Endoh, Iwao Matsumae, Yoshiaki Tanaka, Hiroshi Hosokawa, Mugijiroh Uno, Hiroshi Saitoh, Eiji Takenaka, Tetsuo Yamanaka, Eisaku Murakami, Satoru Komatsubara
  • Toner for developing an electrostatic image
    Patent number: 6033820
    Abstract: A toner for developing an electrostatic image is disclosed. The toner is composed of association of a plurality of fine polymer particles, and the total volume of pores having a diameter of not more than 0.1 .mu.m on the toner surfaces is not more than 30 percent of the total toner volume. An image forming method employing the same is also disclosed. A toner which does not result in an unstable charge amount over an extended period of use can be obtained.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: March 7, 2000
    Assignee: Konica Corporation
    Inventors: Kenji Hayashi, Naohiro Hirose, Yoshiki Nishimori, Tomoe Kitani, Mikio Kohyama
  • Electrostatic image developing toner
    Patent number: 6030739
    Abstract: An electrostatic image developing toner containing a polysiloxane having the following repeating units (a) and ##STR1## wherein R.sup.1 is a C.sub.1 -C.sub.6 alkyl group such as a methyl group or a C.sub.6 -C.sub.12 aryl group such as a phenyl group, which may be different from each other, and R.sup.2 is a C.sub.6 -C.sub.200 saturated hydrocarbon group, provided that the carbon number of R.sup.2 is larger than the carbon number of R.sup.1.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: February 29, 2000
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Tomoko Ishikawa, Noriaki Takahashi, Takayuki Kanai
  • Photoconductive imaging members with polymetallosiloxane layers
    Patent number: 6030735
    Abstract: A photoconductive imaging member comprised of a supporting substrate, a hole blocking layer thereover, a photogenerating layer and a charge transport layer, and wherein the hole blocking layer is comprised of a polymetallosiloxane.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: February 29, 2000
    Assignee: Xerox Corporation
    Inventor: Brian E. Springett
  • Electrophotographic photoconductor with polysiloxane mixture
    Patent number: 6030736
    Abstract: An electrophotographic photoconductor is provided which includes a photoconductive layer formed overlying an electroconductive substrate, wherein the photoconductor includes in a top layer thereof a polysiloxane mixture selected from the group consisting of a polysiloxane mixture of an unmodified polysiloxane compound and a modified polysiloxane compound, a mixture of a methacryl modified polysiloxane compound and an alkyl modified polysiloxane compound, a mixture of a methacryl modified polysiloxane compound and a vinyl modified polysiloxane compound, and a mixture of an alkyl modified polysiloxane compound and a vinyl modified polysiloxane compound. The photoconductor has good durability.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: February 29, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Takaaki Ikegami, Yasuo Suzuki, Hiroshi Nakai, Nozomu Tamoto, Koji Kishida
  • Electrophotographic photoconductor with water vapor permeability
    Patent number: 6030733
    Abstract: An electrophotographic photoconductor including a photoconductive layer which is formed overlying an electroconductive substrate and which includes at least a charge transporting polymer material, wherein the photoconductive layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.-2 .multidot.24 h.sup.-1. The photoconductive layer may be a functionally separated photoconductive layer including a charge generating layer and a charge transporting layer which is formed overlying the charge generating layer and which includes the charge transporting polymer material, wherein the charge transporting layer has a water vapor permeability not greater than about 200 g.multidot.m.sup.2 .multidot.24 h.sup.-1.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: February 29, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Tetsuro Suzuki, Narihito Kojima, Hiroshi Nagame, Hiroshi Tamura, Yohta Sakon, Hiroshi Ikuno
  • Image forming apparatus employing electrophotographic photoconductor
    Patent number: 6026262
    Abstract: An image forming apparatus has a charging unit, an image exposure unit, a reversal development unit, an image transfer unit, and an electrophotographic photoconductor including an electroconductive support and a photoconductive layer formed thereon, the photoconductive layer being provided by coating and drying a photoconductive layer formation liquid containing a solvent, with a change in the content of the solvent in the photoconductive layer dried being 10% or less 24 hours after the drying thereof.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: February 15, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Takehiko Kinoshita, Yasuo Suzuki
  • Electrophotographic developer and producing method thereof
    Patent number: 6025106
    Abstract: An object of the present invention is to provide an electrophotographic developer having a good fluidity, an excellent shelf stability, and a lesser reduction in image quality under various conditions.An electrophotographic one component nonmagnetic developer includes toner particles obtained by polymerizing a polymerizable monomer component, such as styrene, methacrylate, acrylate and the like, and outer-additives, such as silicon dioxide particles, on the toner particles. The developer has pH of 4 to 7 measured by a decoction method, and .sigma.2 of not more than 20 .mu.S/cm and .sigma.2 - .sigma.1 of 0 to 10 .mu.S/cm, in which .sigma.1 is an electric conductivity of water, .sigma.2 is an electric conductivity measured by a decoction method.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: February 15, 2000
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Hidetoshi Azuma, Hiroshi Yamamoto
  • Photoreceptor for electrophotography, bishydrazone compound and intermediate thereof, and method for producing bishydrazone compound and intermediate thereof
    Patent number: 6022655
    Abstract: A photoreceptor for electrophotography of the present invention includes a photosensitive layer provided on a conductive support, the photosensitive layer containing a bishydrazone compound represented by the following general formula (Ia): ##STR1## where: R.sup.1 and R.sup.2 each represent a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a heterocyclic group, or an alkyl group which has 1 to 4 carbon atoms;"a" represents an alkyl group which has 1 to 3 carbon atoms, an alkoxy group which has 1 to 3 carbon atoms, a dialkylamino group which has 1 to 3 carbon atoms, a halogen atom, or a hydrogen atom; andn represents an integer of 1 to 3, wherein, if n is 2 or greater, a plurality of "a" substituents may be identical to or different from one another, or the substituents may form a ring.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: February 8, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Akihiro Kondo, Hiroshi Sugimura, Yuko Inoue, Takatsugu Obata
  • Toner for developing electrostatic latent image
    Patent number: 6022661
    Abstract: The present invention provides a toner, comprising;toner particles containing at least a binder resin and a colorant, and having an average degree of roundness from 0.960 to 1.0 and a standard deviation of degree of roundness of not more than 0.040; andsilica particles having an average primary particle size of 16 to 28 nm, in which the number of particles (A) that are less than 15 nm in particle size, the number of particles (B) that are between 15 and 30 nm in particle size and the number of particles (C) that are larger than 30 nm is in relation of B/A>4 and B/C>4.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: February 8, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Katsunori Kurose, Masahiro Anno, Chikara Tsutsui, Minoru Nakamura, Hiroyuki Fukuda
  • Production process of lithographic printing plate
    Patent number: 6022654
    Abstract: Disclosed is a process for producing a lithographic printing plate using a lithographic printing plate precursor comprising a support having a volume resistivity of more than 1.times.10.sup.10 .OMEGA..cm, an electrically conductive layer provided on one surface of the support and having a volume resistivity of 1.times.10.sup.5 .OMEGA..cm or less and a photoconductive layer provided on the electrically conductive layer and containing zinc oxide and a binder, the process comprising applying negative corona discharge to the lithographic printing plate precursor from the photoconductive layer side and at this discharging, contacting an electric conductor having an earth potential at least with the support of the lithographic printing plate precursor to electrically charging the photoconductive layer of the lithographic printing plate precursor.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: February 8, 2000
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Takao Nakayama, Shigeyuki Dan, Ryosuke Itakura, Hideyuki Hattori, Hiroshi Tashiro