Patents Examined by John Goodrow
  • Patent number: 6916587
    Abstract: A toner including at least a binder resin; a colorant; and a charge controlling agent, in which the binder resin includes at least a polyester resin having a molecular weight distribution such that components having a molecular weight not greater than 500 are included in an amount of 4% by weight and at least a peak is present in a range of from 3,000 to 9,000 when measured by Gel Permeation Chromatography. In addition, the binder resin does not include a tetrahydrofuran-insoluble compound and the charge controlling agent is a resin charge controlling agent including at least units obtained from a monomer including a sulfonate group; an aromatic monomer including an electron absorption group; and an acrylic ester and/or a methacrylic ester monomer.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: July 12, 2005
    Assignee: Ricoh Company Limited
    Inventors: Hiroyuki Fushimi, Toshiki Nanya, Osamu Uchinokura, Shinichiro Yagi, Kohki Katoh
  • Patent number: 6875550
    Abstract: A non-magnetic single-component toner 8 of the present invention has toner mother particles 8a, and external additives 12 comprising: two hydrophobic silicas 13, 14 of which particle diameters are different from each other, i.e. a mean primary particle diameter of 7 nm to 12 nm and a mean primary particle diameter of 40 nm to 50 nm, and a hydrophobic rutile/anatase type titanium oxide 15 having a spindle shape of which major axial diameter is in a range from 0.02 nm to 0.10 nm and the ratio of the major axial diameter to the minor axial diameter is set to be 2 to 8, wherein the external additives 12 adhere to the toner mother particles 8a. By the hydrophobic silicas 13, 14 having work function smaller than the work function of the toner mother particles 8a, the negative charging property is imparted to the toner mother particles 8a and the fluidity is also insured.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: April 5, 2005
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Takuya Kadota, Hidehiro Takano, Shinji Yasukawa, Masanao Kunugi
  • Patent number: 6869741
    Abstract: A photoreceptor with good mechanical and physical properties is provided with an overcoat layer comprising a copolymer of an ?,?-ethylenically unsaturated carboxylic acid and an ?,?-ethylenically unsaturated monomer wherein the weight percent of the ?,?-ethylenically unsaturated carboxylic-acid is at least 25% up to 99% of the copolymer. The copolymer may comprise an ?,?-ethylenically unsaturated carboxylic acid and an ?,?-ethylenically unsaturated monomer wherein the copolymer has an acid value of at least 150 mg KOH/g the copolymer. The copolymer may be present in a blend with a second polymer or copolymer comprised of units derived from a second ?,?-ethylenically unsaturated monomer that is different from the an ?,?-ethylenically unsaturated carboxylic acid and/or the ?,?-ethylenically unsaturated monomer.
    Type: Grant
    Filed: June 10, 2002
    Date of Patent: March 22, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jiayi Zhu, Zbigniew Tokarski, Ronald J. Moudry, Kristine A. Fordahl, David T. Ask, Jonas Sidaravicius, Edmundas Montrimas, Kam W. Law, Valentas Gaidelis
  • Patent number: 6846600
    Abstract: A process for producing an electrophotographic photosensitive member comprising the steps of depositing a non-single crystal material composed basically of silicon atoms, on a cylindrical substrate in a deposition chamber, thereafter once taking the substrate with film out of the deposition chamber, then returning it to the deposition chamber, and thereafter again depositing thereon a non-single-crystal material composed basically of carbon atoms. In another embodiment, the process comprises the steps of depositing on a cylindrical substrate a photoconductive layer formed of a non-single crystal material, subjecting to surface processing the deposited film having protrusions present at its surface, and depositing on the processed surface a surface protective layer formed of a non-single-crystal material. Also disclosed is the electrophotographic photosensitive member thus obtained, and an electrophotographic apparatus having that member.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: January 25, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshiyuki Ehara, Junichiro Hashizume, Masaya Kawada, Tetsuya Karaki, Hironori Ohwaki, Kunimasa Kawamura, Ryuji Okamura, Kazuto Hosoi
  • Patent number: 6835518
    Abstract: A toner for electrostatic image development comprising a high-softening point polyester having a softening point of 120° C. or more and 170° C. or less; a low-softening point polyester having a softening point of 80° C. or more and less than 120° C.; and a composite oxide of two or more metals, wherein the composite oxide has a BET specific surface area of 7 m2/g or more. The toner is suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: December 28, 2004
    Assignee: Kao Corporation
    Inventors: Hidenori Tachi, Yasuyuki Tamane, Koji Akiyama, Hiroyuki Kawaji
  • Patent number: 6790575
    Abstract: A two component developer comprising a magnetic toner containing a binder resin and a magnetic particle, and a magnetic carrier containing a magnetic particle, wherein the magnetic toner has an average particle diameter of 4.0 to 10.0 &mgr;m, and contains 5 to 80 No. % of toner particles having particle diameter of 5 &mgr;m or less, and exhibits magnetization of 10 to 25 emu/g under magnetic field of 5 kiloersteds.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: September 14, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Sasaki, Hiroaki Matsuda, Bing Shu, Maiko Kondo, Hiroshi Nakai, Hiroto Higuchi, Yasuaki Iwamoto, Yoshihiro Suguro, Hiroyuki Yoshikawa, Masahide Yamashita, Kazuyuki Yazaki
  • Patent number: 6777152
    Abstract: By atomizing a siloxane and an organic titanium compound for flame combustion, spherical complex oxide fine particles of amorphous silica-titania are obtained having a particle size of 10-300 nm, a specific surface area of 10-100 m2/g, and a titania content of 1-99% by weight. By hydrophobizing the fine particles and adding them to a toner, a developer is obtained which is improved in fluidity, cleanability and uniform and stable charging.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: August 17, 2004
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Yoshiharu Konya, Koichiro Watanabe, Susumu Ueno
  • Patent number: 6764802
    Abstract: A process including: agitating a mixture including a liquid and a plurality of resin particles within a vessel at a first shear condition; circulating a portion of the mixture from the vessel through a mixer; adding not all at once an aggregating agent for the resin particles and mixing the aggregating agent with the circulating mixture portion within the mixer at a second shear condition more intensive than the first shear condition to result in a post-mixer circulating composition; and returning the post-mixer circulating composition to the vessel wherein the post-mixer circulating composition undergoes the agitating at the first shear condition.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: July 20, 2004
    Assignee: Xerox Corporation
    Inventors: Milan Maric, Alan E. J. Toth, Thomas E. Enright, Marko D. Saban
  • Patent number: 6756175
    Abstract: A method of fixing toner in a belt fixing unit having a fixing roller; a heating roller; an endless fixing belt binding the heating roller and the fixing roller under tension therebetween; a pressure roller disposed to face the fixing roller intervening the fixing belt; and a fixing heater disposed inside one of the pressure roller and the heating roller, the method of fixing includes: a step for fixing a toner image on an image fixing material by conveying the toner image on the image fixing material in between a portion of the fixing belt not touching the fixing roller and the pressure roller; featured by the toner particle being spherical having a roundness of 0.96 or more and contains a colorant and resin component containing a modified polyester resin.
    Type: Grant
    Filed: July 5, 2002
    Date of Patent: June 29, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Chiaki Tanaka, Naohiro Watanabe, Hiroshi Yamada, Tsunemi Sugiyama, Hiroshi Yamashita, Kazuhito Watanabe, Masami Tomita
  • Patent number: 6757507
    Abstract: An image formation apparatus develops an electrostatic latent image with a two-component developer consisting of magnetic carriers and toners by using a development apparatus and a latent image supporter including a filler in an outermost layer thereof, the development apparatus having a developer supporter, which has an internally fixed magnetic body and rotates while supporting a developer on a surface thereof, and a developer quantity controller controlling a quantity of the developer which is supported by the developer supporter facing the magnetic body and controlling a height of magnetic brushes and consisting of materials having rigidity or rigidity and magnetic properties, wherein a ratio (Gp/Gd) of a development gap to a doctor gap between the developer supporter and the controller is from 0.7 to 1.0, and a weight-averaged particle diameter of a developer carrier is from 20 to 60 &mgr;m.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: June 29, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Mochizuki, Naohito Shimota, Hiroaki Matsuda, Shinichiro Yagi, Tomomi Tamura, Tatsuya Niimi
  • Patent number: 6746810
    Abstract: An image formation method which remarkably extends developer life while providing size reduction and high speed coloring. Also, a replenishing toner and a method of producing the same, and a toner cartridge. In the image formation method, conducting image formation by an image formation apparatus having a plurality of xerography units, the developer apparatus of at least one xerography unit has a developer recovering mechanism appropriately replenishing a replenishing toner composed of a toner and a carrier into the developer apparatus and recovering an excess portion of a developer from the equipment. The above-mentioned replenishing toner has a carrier content in the range of 5 to 40% by weight, the above-mentioned carrier is a carrier coated with a resin having a specific composition, and/or the above-mentioned toner is in a specific shape. The replenishing toner may be produced using the above-mentioned recovered developer.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: June 8, 2004
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Chiaki Suzuki, Masahiro Takagi, Atsuhiko Eguchi, Satoshi Inoue, Sakon Takahashi, Masahiro Uchida, Rieko Kataoka, Hiroyuki Fukuda, Fusako Kiyono, Eiji Iwasaki
  • Patent number: 6743560
    Abstract: A composition for combating toner marking, in the form of a particulate material dispersed in release agent.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: June 1, 2004
    Assignees: Heidelberger Druckmaschinen AG, NexPress Solutions LLC
    Inventors: Jerry A. Pickering, Dinesh Tyagi, Pauline K. Wenzel
  • Patent number: 6743557
    Abstract: Disclosed is a positive charging single-layer organic photoreceptor for liquid development which comprises a conductive substrate having thereon a photosensitive layer containing a charge generating material, an electron transport material and an organic binder resin comprising a polymer represented by formula (I): wherein R1 and R2 each represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, or R1 and R2 may form a cycloalkyl group in combination; R3, R4, R5, R6, R7, R8, R9, R10 and R11, each represent a hydrogen atom, a halogen atom, an aryl group or an alkyl group; and m and n each represent a molar percentage giving a total of 70 to 95 mol %.
    Type: Grant
    Filed: August 7, 2002
    Date of Patent: June 1, 2004
    Assignee: Fuji Electric Imaging Device Co., Ltd.
    Inventor: Shinichi Omokawa
  • Patent number: 6740463
    Abstract: A method of producing a toner having a process of mixing colored particles and outer-additives by using a mixer with an agitating blade whose shaft portion is sealed with a gas having a flow rate of from 0.4 m3/hr to 3 m3/hr and which rotates at such a high speed as a peripheral speed at a tip of said agitating blade in a range of from 20 m/sec to 50 m/sec. When the colored particles and outer-additives are mixed with each other, there is no generation of aggregates thereby and the toner can be obtained at a high yield. Therefore the toner which hardly generates a white streak and fog, even after a long period of continuous operation of development of electrophotographs is performed, can be obtained.
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: May 25, 2004
    Assignee: Zeon Corporation
    Inventors: Kazunori Shigemori, Hidetoshi Azuma, Yoshihiro Makuta, Hirosi Yamamoto, Nobuyasu Ota, Kazuhiro Sato, Ryuji Ota
  • 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
  • Patent number: 6733942
    Abstract: The present invention relates to a toner composition for electrophotography, used for development of electrostatic image in electrophotography, electrostatic printing, etc., as well as to a process for producing such a toner composition. The toner composition of the present invention comprises a binder resin component [component (A)] and a coloring agent component [component (B)], wherein the binder resin component [component (A)] comprises a particular crosslinked aromatic polyester resin component [component (a-1)] and a particular linear aromatic polyester resin component [component (a-2)] and the proportions of the component (a-1) and the component (a-2) are 5 to 80% by weight [the component (a-1)] and 20 to 95% by weight [the component (a-2)] based on the total weight of the two components.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: May 11, 2004
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Yuji Emura, Shoji Kawasaki, Masaaki Shin, Hiroshi Matsuoka
  • Patent number: 6711369
    Abstract: A photosensitive drum structure for an image forming apparatus. The photosensitive drum structure includes a cylindrical rotary drum having steps at both ends of the circumferential surface thereof, and a photosensitive belt being wound around the rotary drum and attached thereto with an adhesive that is adhered to the steps. Here, a gap is formed between the circumferential surface of the rotary drum and the photosensitive belt. Thus, an inexpensive photosensitive belt is wound around a rotary drum, and a photosensitive drum can be manufactured with a low cost. Also, a nip having a predetermined width is formed on a contact surface between a developer roller and the photosensitive drum, thereby improving development of the image.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: March 23, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jin-soo Lee, Sam-seuk Choi
  • 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
  • Patent number: 6699632
    Abstract: An image forming toner is provided, including at least: a binder resin; a colorant; and a release agent, wherein a volume-average particle diameter of the toner measured by a Coulter counter is from 5 to 8 &mgr;m; the content of the toner having a volume-average particle diameter of not greater than 5 &mgr;m is 60 to 75% by number; and the content of the toner having a number-basis circle-equivalent particle diameter of from 0.6 to 3 &mgr;m measured by a flow-type particle image analyzer is not greater than 25%.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: March 2, 2004
    Assignee: Ricoh Company Limited
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroaki Matsuda, Hiroshi Nakai, Bing Shu, Maiko Kondo
  • Patent number: 6696213
    Abstract: A method of developing a latent electrostatic image using a two-component developer system, having a ratio (Vr/Vp) ranges 1.2<(Vr/Vp)<3 where the (Vp) is a linear speed (Vp)[m/sec] of a photosensitive member and the (Vr) is a linear speed (Vr) [m/sec] of a developing sleeve, and applying a biased direct-current (VB) [by volt] wherein; a developing gap(Gp)[cm] as a distance at the nearest point between a photosensitive member and a developing sleeve is less than or equal to 0.6 mm, a ratio(&rgr;p/&rgr;a) satisfies an expression (&rgr;p/&rgr;a)<0.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: February 24, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Akihiro Kotsugai