Patents by Inventor Tadashi Kasai

Tadashi Kasai 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: 7764887
    Abstract: A developing device includes a developing roller that supplies two-component developer from a developer container to an image carrier, and a first developer supplying unit and a second developer supplying unit arranged in parallel, one closer to the developing roller than the other is to the developing roller. The first developer supplying unit and the second developer supplying unit circularly convey the two-component developer while stirring the two-component developer to supply the two-component developer to the developing roller. The first developer supplying unit and the second developer supplying unit supply different amounts of the two-component developer.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: July 27, 2010
    Assignee: Ricoh Company, Limited
    Inventor: Tadashi Kasai
  • Publication number: 20100028053
    Abstract: A development device includes a development roller, a developer storage, a first rotating member, a second rotating member, and a rotation speed adjuster. The development roller carries a developer containing non-magnetic toner and magnetic carrier. The developer storage stores the developer. The first rotating member is provided in the developer storage at a position near the development roller. The second rotating member is provided in the developer storage at a position farther from the development roller than the first rotating member is. The first rotating member and the second rotating member agitate and convey the developer stored in the developer storage to supply the agitated developer to the development roller. The rotation speed adjuster adjusts a rotation speed of the second rotating member depending on an amount of new toner supplied to the developer storage.
    Type: Application
    Filed: July 20, 2009
    Publication date: February 4, 2010
    Inventor: Tadashi KASAI
  • Patent number: 7548349
    Abstract: In an image forming apparatus configured to electrostatically transfer a toner image formed on an image carrier to a recording medium with image transferring means of the present invention, pressure is applied between the image carrier and the image transferring means. Toner is provided with relatively high hardness in accordance with the pressure beforehand. Image transfer is effected by reducing a potential difference between the image carrier and the recording medium while maintaining an electric field around the toner the same.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: June 16, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasushi Koichi, Mitsuo Aoki, Bing Shu, Koji Suzuki, Shigeru Watanabe, Tadashi Kasai, Yutaka Takahashi
  • Patent number: 7515860
    Abstract: An image forming apparatus comprising: a latent image support for supporting a latent image and a developing device configured to us toner to develop the latent image on said latent image support, the estimated average halftone granularity of the toner imager after developing being 0.25 or less.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: April 7, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20090074439
    Abstract: An image forming apparatus, including a surface-traveling latent image bearer bearing a latent image on the surface thereof; an image developer feeding a toner in a two-component developer including the toner and a carrier to the latent image in a developing area facing the latent image bearer to develop the latent image to form a toner image, including a developer stirrer and feeder circulating the two-component developer in circulation paths while stirring the two-component developer, including a driver independently driving the first and the second stirring and feeding members; a transferer transferring the toner image onto a recording material; and a controller controlling the driver such that an amount of the two-component developer fed by the second stirring and feeding member per unit time is relatively larger than that of the two-component developer fed by the first stirring and feeding member when a predetermined increase condition of stirring is satisfied.
    Type: Application
    Filed: September 3, 2008
    Publication date: March 19, 2009
    Inventor: Tadashi KASAI
  • Patent number: 7457570
    Abstract: It is an object of the present invention to provide a process unit and an image forming apparatus in which generation of loss of image density due to flying off of developer and the edge effect occurring as a side-effect under developing conditions aimed at improving development performance can be reduced, even when a DC bias development system is adopted, and which can suppress developing density unevenness caused by impact occurring on contact of the teeth of gears in the drive system.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: November 25, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Tadashi Kasai, Hideki Kimura, Tsuyoshi Imanura, Katsumi Masuda, Hideo Yoshizawa, Kiyotaka Sakai
  • Publication number: 20080138094
    Abstract: A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 12, 2008
    Inventors: Jun SHIORI, Toshihiro Sugiyama, Atsushi Tano, Tadashi Kasai, Yutaka Takahashi, Takehide Mizutani
  • Publication number: 20070297814
    Abstract: An image forming apparatus that can provide notification, so that maintenance personnel of a manufacturer or the like can be made aware of a usage condition in a case where an unsuitable toner cartridge is intermittently used. The image forming apparatus is equipped with a primary storage section storing specific information concerning a replaceable part, such as a toner cartridge that can be attached or removed from a main body, and a secondary storage section storing information concerning usage of the replaceable part. The specific information is read from the primary storage section in a condition where the replaceable part is attached, and a judgment is made by a judgment section concerning whether the replaceable part is suitable. If the replaceable part cannot be judged as suitable, information concerning the use of the replaceable part is stored in the secondary storage section and notification is provided by a notification section.
    Type: Application
    Filed: June 20, 2007
    Publication date: December 27, 2007
    Applicant: OKI DATA CORPORATION
    Inventor: Tadashi Kasai
  • Publication number: 20070286652
    Abstract: An image forming apparatus comprising: a latent image support for supporting a latent image and a developing device configured to us toner to develop the latent image on said latent image support, the estimated average halftone granularity of the toner imager after developing being 0.25 or less.
    Type: Application
    Filed: August 2, 2007
    Publication date: December 13, 2007
    Inventors: Koji SUZUKI, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Publication number: 20070253720
    Abstract: A developing device includes a developing roller that supplies two-component developer from a developer container to an image carrier, and a first developer supplying unit and a second developer supplying unit arranged in parallel, one closer to the developing roller than the other is to the developing roller. The first developer supplying unit and the second developer supplying unit circularly convey the two-component developer while stirring the two-component developer to supply the two-component developer to the developing roller. The first developer supplying unit and the second developer supplying unit supply different amounts of the two-component developer.
    Type: Application
    Filed: April 19, 2007
    Publication date: November 1, 2007
    Inventor: Tadashi Kasai
  • Patent number: 7273688
    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: August 14, 2006
    Date of Patent: September 25, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Suzuki, Mitsuo Aoki, Bing Shu, Yasushi Koichi, Setsuo Soga, Tadashi Kasai, Yutaka Takahashi
  • Patent number: 7169105
    Abstract: A flexible tube for an endoscope has an elongated tubular core body, and an outer cover which is provided over the core body. The outer cover is composed of an inner layer, an outer layer and at least one intermediate layer. In this flexible tube, any one of the layers is different from one of the other layers in its property. Further, at least one of the layers has a thickness-varying region where the thickness of the layer varies in its longitudinal direction. In addition, the inner layer of the outer cover has projections which are integrally formed on the inner layer so that the projections project into holes and/or the recesses formed on the core body. This structure makes it possible to produce a flexible tube for an endoscope that has high durability, high flexibility and high chemical resistance as well as excellent operationability.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: January 30, 2007
    Assignee: PENTAX Corporation
    Inventors: Kikuo Iwasaka, Tadashi Kasai, Hideo Nanba, Masaru Takeshige, Akira Sugiyama, Keiji Kunii, Masanao Abe
  • 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
  • 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: 20060152572
    Abstract: An image forming apparatus according to this invention prevents adverse effects on peripheral circuits and speeds up data transfer by preventing a mutual interference among signals. In the image forming apparatus, a transfer controller which converts into a differential serial data pair (data+/?) multiplex data td [6:0] multiplexed from head data vd [7:0], a head control signal vctl [3:0], a data enable signal dten, and a control enable signal cten, converts as well a clock signal clk into a differential clock signal pair (clk+/?), and transfers those differential serial data pair and differential clock signal pair to an LED head via a cable. The LED head receives both of the differential serial data pair and the differential clock signal pair to separate those pairs into head data hd [7:0], head control signal hctl [3:0], and data transfer clock hclk.
    Type: Application
    Filed: January 3, 2006
    Publication date: July 13, 2006
    Inventor: Tadashi Kasai
  • Publication number: 20060029435
    Abstract: It is an object of the present invention to provide a process unit and an image forming apparatus in which generation of loss of image density due to flying off of developer and the edge effect occurring as a side-effect under developing conditions aimed at improving development performance can be reduced, even when a DC bias development system is adopted, and which can suppress developing density unevenness caused by impact occurring on contact of the teeth of gears in the drive system.
    Type: Application
    Filed: August 5, 2005
    Publication date: February 9, 2006
    Inventors: Tadashi Kasai, Hideki Kimura, Tsuyoshi Imanura, Katsumi Masuda, Hideo Yoshizawa, Kiyotaka Sakai
  • 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
  • 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