Patents by Inventor Yasuo Takuma

Yasuo Takuma 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: 9031471
    Abstract: A development device having a development portion with a developer spout, to develop a latent image formed on an image carrier with developer including toner and carrier particles. The development unit also includes a circulation unit to convey developer collected from the development portion to the developer spout, a developer container, provided in the circulation unit, to contain the developer at a position upstream from the development portion in a developer circular direction, the developer container having a cylindrical upper portion and a funnel-shaped lower portion continuous with the cylindrical upper portion through a joint so that a level of the developer contained in the developer container at rest is positioned near the joint between the cylindrical upper portion and the funnel-shaped lower portion. An agitator is provided inside the developer container, to agitate and mix the collected developer and fresh toner supplied to the developer container.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: May 12, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoya Ohmura, Yasuo Takuma, Junichi Matsumoto, Hiroshi Kikuchi, Natsumi Matsue
  • Patent number: 8688012
    Abstract: In a disclosed developing device, a developing part includes a developer carrier for circulating a developer inside the developing part and for supplying the developer to an image carrier, a developer supply member for supplying the developer to the developer carrier, and a developer collection member for collecting the developer which is not used. A developer stirring part is arranged at a different position from a position of the developing part. A developer conveyance part carries the developer by an air conveyance in a developer conveyance path from the developer stirring part to the developing part. A developer detection part includes an opening which communicates between the developer supply member and the developer collection member, is arranged at a downstream side in a flow direction of the developer below and near the developer supply member, and detects whether the developer exists in a vicinity of the developer supply member.
    Type: Grant
    Filed: November 2, 2011
    Date of Patent: April 1, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Yasuo Takuma, Hiroshi Kikuchi, Natsumi Matsue
  • Patent number: 8682187
    Abstract: A development device includes a development portion, to develop a latent image formed on a latent image carrier with developer, disposed close to the latent image carrier; a developer agitation container to agitate the developer, provided separately from the development portion; a transport system connecting the development portion and the developer agitation container, through which the developer is transported from the developer agitation container to the development portion by air; and a developer retainer to temporarily retain the developer, disposed downstream from the transport system, to which the developer remaining in the transport system escapes.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: March 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuo Takuma, Junichi Matsumoto, Tomoya Ohmura, Hiroshi Kikuchi, Natsumi Matsue
  • Patent number: 8666288
    Abstract: A developing device in the embodiment includes: a developer carrier that carries a two-component developer, moves the surface, and supplies the toner to a latent image on a surface of a latent image carrier; a first conveying member that conveys the developer in a first conveying path; a second conveying member that conveys the developer in a second conveying path; and a developer passing unit that conveys upward the developer which has reached at a conveying-direction posterior end of the second conveying path and passes the developer to the first conveying path. The developer passing unit includes a plurality of pushing members that push up the developer. The developer can pass through from upper surfaces of the pushing members to lower surfaces of the pushing members.
    Type: Grant
    Filed: August 24, 2011
    Date of Patent: March 4, 2014
    Assignee: Ricoh Company, Limited
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Yasuo Takuma, Hiroshi Kikuchi, Natsumi Matsue
  • Patent number: 8639150
    Abstract: A development device includes a developing section to visualize a latent image formed on a latent image carrier with developer including toner and carrier. The development device has a developer supply opening and a developer collection opening, a circulation unit to transport the developer collected from the developer collection opening of the developing section to the developer supply opening of the developing section and including a developer container to store the developer collected from the developing section disposed upstream from the development section in a direction in which the developer is circulated, and a developer cooler to cool the developer contained in the developer container.
    Type: Grant
    Filed: January 20, 2011
    Date of Patent: January 28, 2014
    Assignee: Ricoh Company Limited
    Inventors: Tomoya Ohmura, Yasuo Takuma, Junichi Matsumoto, Hiroshi Kikuchi, Natsumi Katoh
  • Patent number: 8615186
    Abstract: A development device includes a development portion to develop a latent image; an agitation container to contain developer; a circulation system through which the developer is circulated between the development portion and the agitation container; a developer replenishing device to supply fresh developer to the agitation container; an agitator, provided inside the agitation container, to agitate and mix the developer collected from the development portion and the fresh developer from the developer replenishing device; and a developer escape chamber to discharge surplus developer in the agitation container, projecting from and continuous with the agitation container, the developer escape chamber defining a communication pathway in a side of the agitation container between the agitation container and the developer escape chamber through which the developer is moved between the agitation container and the developer escape chamber and having a discharge opening whose lower end is positioned higher than the commun
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: December 24, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Kikuchi, Yasuo Takuma, Junichi Matsumoto, Tomoya Ohmura
  • Patent number: 8515316
    Abstract: A developing device includes a developer supply part and a developer collecting part, wherein the developer supply part has a developer inlet port for introducing a developer supplied from a reservoir into the developer supply part and a developer extraction port provided on the side of the developer inlet port to remove a portion of the developer so as to define a quantity of the developer to be introduced in the developer supply part, and wherein the developer extraction port and the developer collecting part are connected to the reservoir.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Natsumi Matsue, Yasuo Takuma, Hiroshi Kikuchi
  • Publication number: 20120230733
    Abstract: A development device includes a development portion to develop a latent image; an agitation container to contain developer; a circulation system through which the developer is circulated between the development portion and the agitation container; a developer replenishing device to supply fresh developer to the agitation container; an agitator, provided inside the agitation container, to agitate and mix the developer collected from the development portion and the fresh developer from the developer replenishing device; and a developer escape chamber to discharge surplus developer in the agitation container, projecting from and continuous with the agitation container, the developer escape chamber defining a communication pathway in a side of the agitation container between the agitation container and the developer escape chamber through which the developer is moved between the agitation container and the developer escape chamber and having a discharge opening whose lower end is positioned higher than the commun
    Type: Application
    Filed: February 21, 2012
    Publication date: September 13, 2012
    Inventors: Hiroshi KIKUCHI, Yasuo TAKUMA, Junichi MATSUMOTO, Tomoya OHMURA
  • Publication number: 20120114349
    Abstract: In a disclosed developing device, a developing part includes a developer carrier for circulating a developer inside the developing part and for supplying the developer to an image carrier, a developer supply member for supplying the developer to the developer carrier, and a developer collection member for collecting the developer which is not used. A developer stirring part is arranged at a different position from a position of the developing part. A developer conveyance part carries the developer by an air conveyance in a developer conveyance path from the developer stirring part to the developing part. A developer detection part includes an opening which communicates between the developer supply member and the developer collection member, is arranged at a downstream side in a flow direction of the developer below and near the developer supply member, and detects whether the developer exists in a vicinity of the developer supply member.
    Type: Application
    Filed: November 2, 2011
    Publication date: May 10, 2012
    Applicant: RICOH COMPANY, LTD.
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Yasuo Takuma, Hiroshi Kikuchi, Natsumi Matsue
  • Publication number: 20120057890
    Abstract: A development device includes a development portion, to develop a latent image formed on a latent image carrier with developer, disposed close to the latent image carrier; a developer agitation container to agitate the developer, provided separately from the development portion; a transport system connecting the development portion and the developer agitation container, through which the developer is transported from the developer agitation container to the development portion by air; and a developer retainer to temporarily retain the developer, disposed downstream from the transport system, to which the developer remaining in the transport system escapes.
    Type: Application
    Filed: August 30, 2011
    Publication date: March 8, 2012
    Applicant: Ricoh Company, Ltd.
    Inventors: Yasuo Takuma, Junichi Matsumoto, Tomoya Ohmura, Hiroshi Kikuchi, Natsumi Matsue
  • Publication number: 20120051791
    Abstract: A development device includes a development portion, having a developer spout, to develop a latent image formed on a latent image carrier with developer including toner and carrier particles; a circulation unit to convey developer collected from the development portion to the developer spout in the development portion; a developer container, provided in the circulation unit, to contain the developer at a position upstream from the development portion in a developer circular direction, the developer container having a cylindrical upper portion and a funnel-shaped lower portion continuous with the cylindrical upper portion through a joint so that a level of the developer contained in the developer container at rest is positioned near the joint between the cylindrical upper portion and the funnel-shaped lower portion; and an agitator, provided inside the developer container, to agitate and mix the collected developer and fresh toner supplied to the developer container.
    Type: Application
    Filed: August 23, 2011
    Publication date: March 1, 2012
    Applicant: Ricoh Company, Ltd.
    Inventors: Tomoya Ohmura, Yasuo Takuma, Junichi Matsumoto, Hiroshi Kikuchi, Natsumi Matsue
  • Publication number: 20120051792
    Abstract: A developing device in the embodiment includes: a developer carrier that carries a two-component developer, moves the surface, and supplies the toner to a latent image on a surface of a latent image carrier; a first conveying member that conveys the developer in a first conveying path; a second conveying member that conveys the developer in a second conveying path; and a developer passing unit that conveys upward the developer which has reached at a conveying-direction posterior end of the second conveying path and passes the developer to the first conveying path. The developer passing unit includes a plurality of pushing members that push up the developer. The developer can pass through from upper surfaces of the pushing members to lower surfaces of the pushing members.
    Type: Application
    Filed: August 24, 2011
    Publication date: March 1, 2012
    Applicant: Ricoh Company, Limited
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Yasuo Takuma, Hiroshi Kikuchi, Natsumi Matsue
  • Publication number: 20110229207
    Abstract: A developing device includes a developer supply part and a developer collecting part, wherein the developer supply part has a developer inlet port for introducing a developer supplied from a reservoir into the developer supply part and a developer extraction port provided on the side of the developer inlet port to remove a portion of the developer so as to define a quantity of the developer to be introduced in the developer supply part, and wherein the developer extraction port and the developer collecting part are connected to the reservoir.
    Type: Application
    Filed: March 11, 2011
    Publication date: September 22, 2011
    Inventors: Junichi Matsumoto, Tomoya Ohmura, Natsumi Matsue, Yasuo Takuma, Hiroshi Kikuchi
  • Publication number: 20110182610
    Abstract: A development device includes a developing section to visualize a latent image formed on a latent image carrier with developer including toner and carrier. The development device has a developer supply opening and a developer collection opening, a circulation unit to transport the developer collected from the developer collection opening of the developing section to the developer supply opening of the developing section and including a developer container to store the developer collected from the developing section disposed upstream from the development section in a direction in which the developer is circulated, and a developer cooler to cool the developer contained in the developer container.
    Type: Application
    Filed: January 20, 2011
    Publication date: July 28, 2011
    Inventors: Tomoya OHMURA, Yasuo Takuma, Junichi Matsumoto, Hiroshi Kikuchi, Natsumi Katoh
  • Patent number: 7962055
    Abstract: According to one embodiment, an image forming apparatus includes a photoreceptor, a charging unit, an exposure unit, a developing unit, a transfer unit, a fixing unit, an environment detecting unit and a control unit. The charging unit includes a charger and a static eliminator. The charger contacts with a surface of the photoreceptor and charges the surface to a first voltage. The static eliminator contacts with the surface and discharges the surface to a second voltage. The environment detecting unit detects an environmental data. The control unit controls the first voltage based on the environmental data.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: June 14, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuo Takuma, Masanari Fujita, Masaki Tsuchiya, Nobuaki Fukasawa
  • Patent number: 7796905
    Abstract: A multicolor image forming apparatus includes: a photosensitive belt unit comprising; a driving roller; a driven roller; a photosensitive belt having a joint, and a charger charging a surface of the photosensitive belt; an exposure device forming an electrostatic latent image, based on image information of each color, on the photosensitive belt; a plurality of developing devices storing different color developers, and an intermediate transfer unit performing a first transfer by sequentially superimposing each color developer image formed on the photosensitive belt. The photosensitive belt is suspended around the driving roller and the driven roller and is rotated and driven by the driving roller. Each developing device contacts and retracts from the photosensitive belt so as to develop the electrostatic latent image into a visible image using each color developer. At least one developing device can retract from the photosensitive belt at a region other than an image region.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: September 14, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruyuki Honda, Masahiko Saito, Masanari Fujita, Masashi Yamamoto, Yasuo Takuma
  • Patent number: 7493063
    Abstract: An image-forming device including a plurality of supporting rollers, a photosensitive belt, a pressing roller, an intermediate roller, and a charging roller. The plurality of supporting rollers includes a preselected supporting roller. The photosensitive belt is circularly movably supported on the plurality of supporting rollers. The pressing roller is disposed to contact the photosensitive belt and to press the preselected supporting roller through the photosensitive belt. The intermediate roller is disposed away from the photosensitive belt and to contact the pressing roller. The intermediate roller is rotatable following rotation of the pressing roller. The charging roller is disposed to contact both the photosensitive belt and the intermediate roller and to press the preselected supporting roller through the photosensitive belt. The charging roller is rotatable following rotation of the intermediate roller to thereby charge the photosensitive belt.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: February 17, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuo Takuma, Masashi Yamamoto, Masanari Fujita
  • Patent number: 7463849
    Abstract: An image forming apparatus includes a photosensitive member being movable in a predetermined direction; a charging roller that charges a surface of the photosensitive member; and a static pre-eliminator that eliminates static electricity by irradiating the surface of the photosensitive member with light, the static pre-eliminator located on an upstream side of the charging roller in a direction of movement of the photosensitive member; wherein an arrangement and an exposure amount of the static pre-eliminator are set to satisfy E ?0.025×exp(t/?) where ?is a residual time constant of a photo carrier generated in the photosensitive member by the static pre-eliminator, t is a time period from a time when the photosensitive member passes through the static pre-eliminator to a time when the photosensitive member is charged by the charging roller, and E is a normalized exposure amount of the static pre-eliminator.
    Type: Grant
    Filed: January 24, 2006
    Date of Patent: December 9, 2008
    Assignee: Ricoh Printing Systems, Ltd.
    Inventors: Yasuo Takuma, Masashi Yamamoto, Masanari Fujita
  • Publication number: 20070286633
    Abstract: According to one embodiment, an image forming apparatus includes a photoreceptor, a charging unit, an exposure unit, a developing unit, a transfer unit, a fixing unit, an environment detecting unit and a control unit. The charging unit includes a charger and a static eliminator. The charger contacts with a surface of the photoreceptor and charges the surface to a first voltage. The static eliminator contacts with the surface and discharges the surface to a second voltage. The environment detecting unit detects an environmental data. The control unit controls the first voltage based on the environmental data.
    Type: Application
    Filed: April 18, 2007
    Publication date: December 13, 2007
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Yasuo Takuma, Masanari Fujita, Masaki Tsuchiya, Nobuaki Fukasawa
  • Publication number: 20070031167
    Abstract: A multicolor image forming apparatus includes: a photosensitive belt unit comprising; a driving roller; a driven roller; a photosensitive belt having a joint, and a charger charging a surface of the photosensitive belt; an exposure device forming an electrostatic latent image, based on image information of each color, on the photosensitive belt; a plurality of developing devices storing different color developers, and an intermediate transfer unit performing a first transfer by sequentially superimposing each color developer image formed on the photosensitive belt. The photosensitive belt is suspended around the driving roller and the driven roller and is rotated and driven by the driving roller. Each developing device contacts and retracts from the photosensitive belt so as to develop the electrostatic latent image into a visible image using each color developer. At least one developing device can retract from the photosensitive belt at a region other than an image region.
    Type: Application
    Filed: July 21, 2006
    Publication date: February 8, 2007
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Haruyuki Honda, Masahiko Saito, Masanari Fujita, Masashi Yamamoto, Yasuo Takuma