Patents by Inventor Mitsuo Aoki

Mitsuo Aoki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7177555
    Abstract: The image forming apparatus comprises a photoconductor, a latent electrostatic image forming unit for forming a latent electrostatic image on the photoconductor, a developing unit for developing the latent electrostatic image using a developer comprising a toner to form a visible image, a transfer unit for transferring the visible image to a recording medium, a cleaning unit for removing the developer remained on the photoconductor surface and a developer amount detection unit for detecting developer amount adhering to the photoconductor surface by a reflecting photosensor, wherein the developer stirring time per copy when one copy is made from an original, is 2 to 6 times the developer stirring time per copy when two or more copies are made from the original, wherein the toner comprises at least a binder resin and a wax, and the dynamic frictional coefficient of the toner is 0.15 to 0.45.
    Type: Grant
    Filed: January 15, 2004
    Date of Patent: February 13, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Bing Shu, Mitsuo Aoki, Haruji Mizuishi, Mikio Ishibashi, Masaru Tanaka, Shinji Tamaki, Hiroshi Mizusawa, Shin Hasegawa
  • Patent number: 7163774
    Abstract: A toner including a binder resin including a crystalline polyester and a non-crystalline resin; a release agent; and a black metal-containing material having a saturation magnetization not greater than 50 emu/g. A toner container containing the toner. A fixing method including passing a support with the toner image thereon through a nip between two cylindrical rollers while applying a pressure not greater than 1×105 Pa to the two cylindrical rollers, wherein one of the cylindrical rollers which contacts the toner image has a thickness not greater than 1.0 mm. An image forming method including developing an electrostatic image with the toner to form a toner image; transferring the toner image onto a receiving material; and fixing the toner image by the fixing method mentioned above. A process cartridge including an image bearing member and a developing device using the toner.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: January 16, 2007
    Assignee: Ricoh Company Limited
    Inventors: Keiko Shiraishi, Toyoshi Sawada, Masashi Nagayama, Shinichi Kuramoto, Mitsuo Aoki, Kumi Hasegawa, Bing Shu
  • Patent number: 7162187
    Abstract: In an image forming apparatus, a toner image is formed on a photosensitive element and a transfer roller, which carries a transfer medium, is pressed against a photosensitive element at a pressure of from 20.4 N/cm2 to 200 N/cm2.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: January 9, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasushi Koichi, Mitsuo Aoki, Bing Shu, Setsuo Soga, Koji Suzuki, Yutaka Takahashi, Tadashi Kasai
  • Patent number: 7150954
    Abstract: An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume V1 and a toner image area S1, wherein the toner image after the passage through the nip has a toner volume V2 and a toner image area S2, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively: Vt(%)=(V1?V2)/V1×100 St(%)=(S2?S1)/S1×100. Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 ?m or less.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: December 19, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuo Aoki, Kumi Hasegawa, Toshiaki Higaya, Yasushi Koichi, Yutaka Takahashi, Tadashi Kasai
  • Publication number: 20060275688
    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: August 14, 2006
    Publication date: December 7, 2006
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20060240350
    Abstract: A developer contains a toner; and a carrier, wherein the toner contains toner particles containing a binder resin; and a colorant, and a titanium oxide as an external additive, wherein an amount of free titanium oxide particles released from the toner determined by a ultrasonic vibration method is from 5 to 22% by weight per total weight of the toner, and wherein the toner has a charge quantity distribution property so that a peak is present in a charge quantity range of from 20 to 40 ?C/g in absolute value, wherein the charge quantity distribution of the toner is determined by an increment method in which the developer including the toner is subjected to a blow off treatment to measure a charge quantity of the toner at 23° C. and 55% RH.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 26, 2006
    Inventors: Hyo Shu, Mitsuo Aoki
  • Patent number: 7125638
    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: Grant
    Filed: March 23, 2004
    Date of Patent: October 24, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20060124267
    Abstract: In order to provide a band-like apparatus cleaning device for removing foreign materials and cleaning a band-like apparatus before the foreign materials become huge on the surface of the band-like apparatus without scattering the foreign materials around by improving a cleaning structure such as the shape of an aperture for shower and the like for the band-like apparatus, there is provided a cleaning device of a band-like apparatus, comprising a hollow rotating roll being supported so as to be capable of turning along the traveling direction of the band-like apparatus and having a plurality of apertures for shower formed in it, and cleaning fluid jetting nozzles arranged at the inner side of the plurality of apertures for shower within an embracing angle of the band-like apparatus wound partially round the rotating roll, the cleaning device cleaning the band-like apparatus by jetting a cleaning fluid to the band-like apparatus from the cleaning fluid jetting nozzles, wherein the cleaning device comprises a pl
    Type: Application
    Filed: August 19, 2003
    Publication date: June 15, 2006
    Inventor: Mitsuo Aoki
  • Publication number: 20060093943
    Abstract: A magenta color toner including toner particles including a binder resin including a polyester resin including an inorganic tin (II) compound; a colorant having one of naphthol compounds having one of specific formulae. A process cartridge in which includes a photoreceptor bearing an electrostatic latent image; and a developing device configured to develop the latent image with a developer including the magenta color toner to from a toner image on the photo receptor are unitized. An image forming apparatus including a photoreceptor; a charger configured to charge the photoreceptor; a light irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image; a developing device configured to develop the latent image with a developer including the magenta color toner to from a toner image on the photoreceptor; and a transfer device configured to transfer the toner image onto a receiving material.
    Type: Application
    Filed: October 27, 2005
    Publication date: May 4, 2006
    Inventors: Hyo Shu, Mitsuo Aoki, Minoru Masuda, Kumi Hasegawa
  • Patent number: 7029816
    Abstract: An image formation method includes the steps of charging the surface of an electrophotographic photoconductor, exposing the charged photoconductor to a light image to form a latent electrostatic image on the photoconductor, developing the latent electrostatic image using a two-component developer containing a toner and a carrier to obtain a toner image, and transferring the toner image to an image receiving material directly or via an intermediate transfer member, with the photoconductor showing a surface friction coefficient of 0.40 or less, and the toner having toner particles with an average circularity of 0.930 or more.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: April 18, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Fumihiro Sasaki, Mitsuo Aoki, Yasuaki Iwamoto, Naohito Shimota, Kazuyuki Yazaki, Hiroaki Matsuda, Hiroshi Nakai, Kumi Hasegawa, Shinichiro Yagi, Hiroto Higuchi, Akemi Sugiyama
  • Publication number: 20060068306
    Abstract: An image forming apparatus of the present invention includes a latent electrostatic image bearing member, a latent electrostatic image forming unit configured to form a latent electrostatic image on the latent electrostatic image bearing member, at least three developing units each configured to develop the latent electrostatic image using a toner to form a visible image, a transferring unit configured to transfer the visible image on a recording medium, and an image fixing unit configured to the transferred image on the recording medium, in which the developing units respectively include any one of a yellow toner, a magenta toner, and a cyan toner, the magenta toner includes C.I. pigment red 269, and the yellow toner includes C.I pigment yellow 180 or C.I pigment yellow 155.
    Type: Application
    Filed: September 13, 2005
    Publication date: March 30, 2006
    Inventors: Hyo Shu, Mitsuo Aoki, Minoru Masuda, Kumi Hasegawa
  • Publication number: 20060063092
    Abstract: The object is to provide a toner which can be smoothly replrenished by a toner replenishing device using a powder pump even when the toner containes a releasing agent, and an image forming apparatus using the toner. There is provided a toner, which comprises a binder resin, a colorant and a releasing agent, has a dynamic friction coefficient of 0.15 to 0.35, and is replenished by the toner replenishing device having a powder pump configured to automatically supply the toner and a toner container arranged in conjuction with the powder pump so as to develop a latent electrostatic image on a image bearing member.
    Type: Application
    Filed: September 16, 2005
    Publication date: March 23, 2006
    Inventors: Kumi Hasegawa, Mitsuo Aoki, Hyo Shu, Minoru Masuda, Tomoko Utsumi
  • Publication number: 20060051692
    Abstract: A full color toner containing a binder resin, a release agent and a colorant is provided, wherein the binder resin contains a polyester resin containing a hybrid resin containing one or more vinyl group polymer units and one or more polyester units, and wherein the content A of the hybrid resin and the content B of the release agent satisfy the following relationship: B/2?A?3B.
    Type: Application
    Filed: August 3, 2005
    Publication date: March 9, 2006
    Inventors: Kumi Hasegawa, Mitsuo Aoki, Minoru Masuda, Hyo Shu
  • Patent number: 6964835
    Abstract: A toner including a at least a binder resin; a colorant; and a zirconium compound including zirconium and at least one of an aromatic oxycarboxylic acid and a salt thereof, wherein the zirconium compound having a main diffraction peak (A) at a Bragg (2?) angle of 5.5±0.3° and a diffraction intensity of from 2,000 to 15,000 cps when irradiated with a specific X-ray of CuK?.
    Type: Grant
    Filed: July 21, 2003
    Date of Patent: November 15, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Kumi Hasegawa, Mitsuo Aoki
  • Publication number: 20050208403
    Abstract: A toner including toner particles including a binder resin containing at least one polyester resin comprising an inorganic tin (II) compound and an external additive including a particulate inorganic material having a volume average particle diameter greater than 70 nm and less than 300 nm. The binder resin preferably includes a polyester resin having a weight average molecular weight of from 5,000 to 50,000 and another resin having a weight average molecular weight of from 200,000 to 400,000. A developer including the toner; and a developing device, an image forming apparatus and a process cartridge, which form toner images using the toner are also provided.
    Type: Application
    Filed: March 15, 2005
    Publication date: September 22, 2005
    Inventors: Hyo Shu, Mitsuo Aoki, Minoru Masuda, Kumi Hasegawa
  • Patent number: 6934484
    Abstract: In a copier which is an image-forming apparatus comprising a photoconductor 1, a developing apparatus 4, transfer apparatus 5 which transfers a toner image formed on the photoconductor 1 to a transfer material by heat and pressure using a transfer roller 52, and a fixing apparatus which fixes the toner image transferred to the transfer material, on the transfer material, a heater 56, temperature detection apparatus 57 and temperature control apparatus are provided which controls the temperature to within a range of from the glass transition temperature (Tg) to the softening temperature (Tm) of the toner, and lower than the fixing temperature of the fixing apparatus 7.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: August 23, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Hiroto Higuchi, Shinya Nakayama, Maiko Kondo, Bing Shu, Yasushi Koichi, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20050175924
    Abstract: A toner including a at least a binder resin; a colorant; and a zirconium compound including zirconium and at least one of an aromatic oxycarboxylic acid and a salt thereof, wherein the zirconium compound having a main diffraction peak (A) at a Bragg (2?) angle of 5.5±0.3° and a diffraction intensity of from 2,000 to 15,000 cps when irradiated with a specific X-ray of CuK?.
    Type: Application
    Filed: July 21, 2003
    Publication date: August 11, 2005
    Applicant: RICOH COMPANY, LTD.
    Inventors: Kumi Hasegawa, Mitsuo Aoki
  • Patent number: 6924073
    Abstract: A toner for developing an electrostatic latent image, comprising a colorant, a releasing agent and a binder resin, wherein said binder resin comprises a first, non-linear resin, a second, linear resin, and a modified wax comprising a wax moiety and a vinyl polymer moiety having an ester group content of 8 to 30% by weight based on the weight of the vinyl polymer moiety.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: August 2, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Mitsuo Aoki, Fumihiro Sasaki, Naohito Shimota, Kumi Hasegawa, Bing Shu, Maiko Kondo, Shinya Nakayama
  • Patent number: 6899986
    Abstract: An image forming method, comprising passing a toner image-bearing sheet through a nip defined between two rollers including a heater roller to fix the toner image on the sheet, wherein the toner image is formed from a toner comprising a binder resin, and a colorant, wherein the toner image before the passage through the nip has a toner volume V1 and a toner image area S1, wherein the toner image after the passage through the nip has a toner volume V2 and a toner image area S2, and wherein a volume change Vt and an area change St defined by the formulas shown below are 30% or less and 20% or less, respectively: Vt(%)=(V1?V2)/V1×100 St(%)=(S2?S2)/S1×100. Alternatively, the toner image before the passage through the nip has a surface roughness of 2.5 ?m or less.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: May 31, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuo Aoki, Kumi Hasegawa, Toshiaki Higaya, Yasushi Koichi, Yutaka Takahashi, Tadashi Kasai
  • Patent number: 6887636
    Abstract: A toner for a two-component developer comprising the toner and carrier particles, the developer being used for an oilless fixing-type image forming apparatus comprising a developer carrier rotatable at a linear speed of 360-1,680 mm/sec, and a developer adjusting member extending in a lateral direction parallel to the rotational axis of the developer carrier and disposed adjacent to the developer carrier to define a gap therebetween of 0.3-1.0 mm, said image forming apparatus being operated so that the amount of the developer conveyed by the developer carrier and passing through the gap per 1 second is 5.0-25.0 g per 1 cm of the lateral width of the gap, the toner comprising a wax dispersed therein and the toner having a coefficient of dynamic friction in the range of 0.18-0.45.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: May 3, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Matsuda, Kazuyuki Yazaki, Takayuki Koike, Koji Suzuki, Tadashi Kasai, Yutaka Takahashi, Mitsuo Aoki, Naohito Shimota, Akihiro Itoh