Patents by Inventor Hideo Yu

Hideo Yu 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: 6990309
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: January 24, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Patent number: 6701118
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: March 2, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Patent number: 6654574
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charger, a transfer mechanism, a discharger, a direct current (d.c.) voltage source, and a d.c. voltage controller. The intermediate transfer member faces and contacts the image carrying member carrying a toner image, and receives the toner image therefrom during a first transfer. The charger charges the intermediate transfer member to cause an electric field around where the image carrying member and the intermediate transfer member contact each other, the electric field initiating the first transfer. The transfer mechanism transfers the toner image from the intermediate transfer member to a transfer sheet. The discharger discharges charge remaining on the intermediate transfer member. The d.c. voltage source applies a d.c. voltage to the discharger to cause the discharging. The d.c. voltage controller controls the d.c. voltage in accordance with a volume resistivity of the intermediate transfer member.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: November 25, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Publication number: 20030215269
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.
    Type: Application
    Filed: June 19, 2003
    Publication date: November 20, 2003
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Publication number: 20030123911
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.
    Type: Application
    Filed: October 25, 2002
    Publication date: July 3, 2003
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Publication number: 20030118378
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charger, a transfer mechanism, a discharger, a direct current (d.c.) voltage source, and a d.c. voltage controller. The intermediate transfer member faces and contacts the image carrying member carrying a toner image, and receives the toner image therefrom during a first transfer. The charger charges the intermediate transfer member to cause an electric field around where the image carrying member and the intermediate transfer member contact each other, the electric field initiating the first transfer. The transfer mechanism transfers the toner image from the intermediate transfer member to a transfer sheet. The discharger discharges charge remaining on the intermediate transfer member. The d.c. voltage source applies a d.c. voltage to the discharger to cause the discharging. The d.c. voltage controller controls the d.c. voltage in accordance with a volume resistivity of the intermediate transfer member.
    Type: Application
    Filed: October 25, 2002
    Publication date: June 26, 2003
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Patent number: 6505024
    Abstract: An image forming apparatus includes an image carrying member, intermediate transfer member, charger, transfer mechanism, discharger, direct current voltage source, and direct current voltage controller. The intermediate transfer member contacts the image carrying member and receives a toner image therefrom during a first transfer operation. The charger charges the intermediate transfer member to generate an electric field where the image carrying member and the intermediate transfer member contact each other for initiating the first transfer operation. The transfer mechanism performs a second transfer operation to transfer the toner image from the intermediate transfer member to a transfer sheet. The discharger discharges a charge remaining on the intermediate transfer member after completing the second transfer operation by the direct current voltage source applying a direct current voltage to the discharger.
    Type: Grant
    Filed: April 10, 2001
    Date of Patent: January 7, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Publication number: 20020034405
    Abstract: An image forming apparatus includes an image carrying member, intermediate transfer member, charger, transfer mechanism, discharger, direct current voltage source, and direct current voltage controller. The intermediate transfer member contacts the image carrying member and receives a toner image therefrom during a first transfer operation. The charger charges the intermediate transfer member to generate an electric field where the image carrying member and the intermediate transfer member contact each other for initiating the first transfer operation. The transfer mechanism performs a second transfer operation to transfer the toner image from the intermediate transfer member to a transfer sheet. The discharger discharges a charge remaining on the intermediate transfer member after completing the second transfer operation by the direct current voltage source applying a direct current voltage to the discharger.
    Type: Application
    Filed: April 10, 2001
    Publication date: March 21, 2002
    Applicant: RICOH COMPANY, LTD
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Patent number: 6269228
    Abstract: An image forming apparatus includes an image carrying member, an intermediate transfer member, a charging member, a transfer mechanism, a discharging member, a direct current voltage source, and a direct current voltage controller. The intermediate transfer member is deposited at a position facing and in contact with the image carrying member rotatably carrying a toner image on a rotating surface, and receives the toner image therefrom during a first transfer operation. The charging member applies a charge to the intermediate transfer member to cause an electric field around a region where the image carrying member and the intermediate transfer member contact with each other, where the electric field generates a force for initiating the first transfer operation. The transfer mechanism performs a second transfer operation for transferring the toner image from the intermediate transfer member to a transfer sheet.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: July 31, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Kayahara, Hideo Yu, Mitsuru Takahashi, Takeshi Shintani
  • Patent number: 6067435
    Abstract: An image forming apparatus of the type transferring a toner image from a photoconductive element to a recording medium by way of an intermediate transfer belt is disclosed. Toner images of different colors are sequentially transferred from the photoconductive element to the intermediate transfer belt one above the other, forming a full-color image. When the full-color image is to be transferred from the intermediate transfer belt to a paper or similar recording medium, a secondary transfer belt is brought into contact with the portion of the intermediate transfer belt contacting a secondary transfer roller. As a result, the secondary transfer belt deforms complementarily to the shape of the secondary transfer roller, forming a nip between it and the intermediate transfer belt. In this condition, the secondary transfer belt contacts the intermediate transfer belt evenly and prevents an excessive pressure from acting locally on the toner image existing on the intermediate transfer belt.
    Type: Grant
    Filed: September 28, 1998
    Date of Patent: May 23, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Setsuo Soga, Hideo Yu, Jun Okamoto, Yasuhiro Kohira
  • Patent number: 5873017
    Abstract: An image forming apparatus of the type transferring a toner image from a photoconductive element to a recording medium by way of an intermediate transfer belt is disclosed. Toner images of different colors are sequentially transferred from the photoconductive element to the intermediate transfer belt one above the other, forming a full-color image. When the full-color image is to be transferred from the intermediate transfer belt to a paper or similar recording medium, a secondary transfer belt is brought into contact with the portion of the intermediate transfer belt contacting a secondary transfer roller. As a result, the secondary transfer belt deforms complementarily to the shape of the secondary transfer roller, forming a nip between it and the intermediate transfer belt. In this condition, the secondary transfer belt contacts the intermediate transfer belt evenly and prevents an excessive pressure from acting locally on the toner image existing on the intermediate transfer belt.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: February 16, 1999
    Assignee: Ricoh Company Ltd.
    Inventors: Setsuo Soga, Hideo Yu, Jun Okamoto, Yasuhiro Kohira
  • Patent number: 5701566
    Abstract: A device incorporated in an image forming apparatus for transferring a toner image from a photoconductive element to an intermediate transfer belt and then from the intermediate transfer belt to a sheet or similar recording medium. An electrode member is implemented as a belt drive roller and located at the rear of a portion of the intermediate transfer belt which lies in a position for transferring the toner image from the belt to a sheet. The electrode member has a specific volume resistance of 10.sup.7 .OMEGA.cm to 10.sup.12 .OMEGA.cm.
    Type: Grant
    Filed: September 5, 1995
    Date of Patent: December 23, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Bisaiji, Hideo Yu, Yasunori Kawaishi, Toshiaki Motohashi, Mitsuru Takahashi, Hideki Kamiyama
  • Patent number: 5666622
    Abstract: The apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode so as form a potential gradient. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: September 9, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuko Harasawa, Itaru Matsuda, Satoshi Takano, Hideo Yu, Yasunori Kawaishi, Hideki Kamiyama, Toshiaki Motohashi, Mitsuru Takahashi, Takashi Bisaiji
  • Patent number: 5461461
    Abstract: An image forming apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can also be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: October 24, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuko Harasawa, Itaru Matsuda, Satoshi Takano, Hideo Yu, Yasunori Kawaishi, Hideki Kamiyama, Toshiaki Motohashi, Mitsuru Takahashi, Takashi Bisaiji
  • Patent number: 5442428
    Abstract: An image recording apparatus is disclosed which includes an intermediate transfer belt rotatable in a reciprocating motion. Before the belt is rotated back and forth for forming a composite toner image, it is rotated in the opposite direction to the image forming direction. This provides the belt with substantially the same deviation in both the forward movement and the reverse movement. Hence, the apparatus insures desirable images by preventing the individual toner images from being brought out of register due to the deviation of the belt.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: August 15, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuru Takahashi, Yasunori Kawaishi, Hideo Yu, Toshiaki Motohashi, Katsuya Kawagoe, Hideki Kamiyama
  • Patent number: RE38206
    Abstract: A device incorporated in an image forming apparatus for transferring a toner image from a photoconductive element to an intermediate transfer belt and then from the intermediate transfer belt to a sheet or similar recording medium. An electrode member is implemented as a belt drive roller and located at the rear of a portion of the intermediate transfer belt which lies in a position for transferring the toner image from the belt to a sheet. The electrode member has a specific volume resistance of 107 &OHgr;cm to 1012 &OHgr;cm.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: July 29, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Bisaiji, Hideo Yu, Yasunori Kawaishi, Toshiaki Motohashi, Mitsuru Takahashi, Hideki Kamiyama