Patents by Inventor Masashi Takahashi

Masashi Takahashi 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).

  • Image forming apparatus and method having a cleanerless image forming unit
    Patent number: 7426358
    Abstract: There is provided an image forming apparatus comprising a developing device containing a toner having an average particle diameter of 2 to 5 ?m and a spherical degree of 1 to 1.2, and a transfer member which is pressed against the image carrier by a pressing force having a total load of 150 g to 1500 g and a surface load of 10 to 150 g/cm2 at the time of transfer.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: September 16, 2008
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Minoru Yoshida, Takeshi Watanabe, Masashi Takahashi, Toshihiro Kasai, Shoko Shimmura, Takashi Hatakeyama
  • Lens alignment apparatus
    Patent number: 7408726
    Abstract: A lens alignment apparatus includes a main lens holding frame having a main lens secured thereto; an adjusting lens holding frame to which an adjusting lens to be aligned with the main lens is secured; at least one radial groove formed in one of adjacent end surfaces of the main lens holding frame and the adjusting lens holding frame; a centering hole, corresponding to the radial groove, formed in the other of the adjacent end surfaces of the main lens holding frame and the adjusting lens holding frame; and an alignment member including a centering pillar portion inserted in the centering hole and an aligning portion engaged in the radial groove, the aligning portion being provided with a plurality of pairs of parallel alignment surfaces having an identical width and different distances from the axis of the centering pillar portion.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: August 5, 2008
    Assignee: Hoya Corporation
    Inventors: Makoto Iikawa, Masashi Takahashi
  • IMAGE FORMING APPARATUS
    Publication number: 20080166158
    Abstract: In an image forming apparatus adopting a cleanerless process, there is provided a technique of preventing deterioration of picture quality due to photoreceptor filming or color mixture.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 10, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Masashi Takahashi, Minoru Yoshida, Takeshi Watanabe
  • CHARGING DEVICE, IMAGE FORMING APPARATUS AND CHARGING METHOD
    Publication number: 20080166154
    Abstract: A technology capable of realizing a stable charging performance in an image forming apparatus employing a contact charging system is provided. A charging device is configured to have a charging member to which a prescribed bias voltage is applied and which comes into contact with an image carrying surface of an image carrier to charge the image carrying surface; and a particle supply section configured to supply a charging auxiliary particle made of a conductive particle having a diamond particle contained therein in a portion coming into contact with the image carrying surface in the charging member.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 10, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
  • IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD
    Publication number: 20080166143
    Abstract: A technology for controlling the generation of damages of a photoconductive surface caused due to the attachment of a carrier to a photoconductor in an image forming apparatus using a two-component developing agent is provided. An image forming apparatus is configured to include an intermediate transfer body having prescribed elasticity on a transfer surface onto which a toner image is transferred; plural image carriers which transfer a toner image onto the transfer surface and which are disposed along a movement direction of the transfer surface of the intermediate transfer body; plural development sections which form toner images having a different color from each other with respect to the plural image carriers by using a two-component developing agent made of a toner and a carrier; and developing agent replenishment sections which replenish a toner and a carrier in the development sections.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 10, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takeshi Watanabe, Minoru Yoshida, Masashi Takahashi
  • IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD
    Publication number: 20080166159
    Abstract: A technology capable of suppressing the generation of transfer scattering of a toner image on an intermediate transfer body and contributing to an improvement in image quality in an image forming apparatus employing an intermediate transfer system is provided. An image forming apparatus is configured to include an intermediate transfer body to which a toner imager is transferred from an image carrier, the intermediate transfer body having an elastic surface layer having a center point average roughness of 0.1 times or more of a volume average particle size of a used toner and a ten-point average roughness of not more than the volume average particle size of the used toner; and a development section which develops an electrostatic latent image on the image carrier by using a toner having a shape factor SF-1 in the range of from 100 to 130 and a shape factor SF-2 in the range of from 100 to 140.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 10, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takeshi Watanabe, Minoru Yoshida, Masashi Takahashi
  • IMAGE FORMING APPARATUS AND TONER COLLECTION METHOD
    Publication number: 20080166152
    Abstract: There is provided a technique in which in a four-rotation intermediate transfer system image forming apparatus, even in a state where a large amount of transfer residual toner is generated, the occurrence of color mixture of toners can be effectively suppressed.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 10, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Masashi Takahashi, Minoru Yoshida, Takeshi Watanabe
  • IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD HAVING A CLEANER AND A PAPER DETECTION UNIT
    Publication number: 20080124113
    Abstract: An image forming apparatus that forms an image using a photoconductor body includes a switching unit which effects switching between a state in which a cleaner is operated for the photoconductor body, and a state in which the cleaner is not operated for the photoconductor body. A control unit is provided which controls a setting change of an image formation condition between a case where the cleaner is operated by the switching unit, and a case where the cleaner is not operated by the switching unit. The switching unit includes a detection unit which detects the kind of paper on which an image is formed, and the switching unit switches on/off the cleaner in accordance with a detection result of the detection unit.
    Type: Application
    Filed: February 5, 2008
    Publication date: May 29, 2008
    Inventors: Takeshi WATANABE, Masashi Takahashi, Shoko Shimmura, Takashi Hakateyama
  • CHARGING DEVICE, IMAGE FORMING APPARATUS AND CHARGING METHOD
    Publication number: 20080124130
    Abstract: A charging technique in which the generation of ozone is suppressed and charging efficiency can be improved is provided. There are included an elastic body to come in contact with a body to be charged, the elastic body including a portion which comes in contact with the body to be charged and is formed of a material containing a diamond particle, and a voltage application unit to charge the body to be charged by applying a specified bias voltage through the elastic body to the body to be charged.
    Type: Application
    Filed: November 8, 2006
    Publication date: May 29, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
  • Encoding apparatus and encoding method
    Publication number: 20080112486
    Abstract: The calculation processing amount of encoding processing is reduced while suppressing a decrease in encoding efficiency. An encoding method includes the steps of generating predicted image data from an image of a predetermined reference frame; generating differential image data from a difference between the predicted image data and image data of one frame of the input image data; performing discrete cosine transformation processing and quantization processing for the differential image data for generating encoded image data; performing variable-length encoding processing for the encoded image data for generating an encoded stream; and performing reference frame update determination processing in which a correlation between the image of the reference frame and the image of the one frame is determined for deciding whether or not the one frame is to be used as a new reference frame.
    Type: Application
    Filed: November 8, 2007
    Publication date: May 15, 2008
    Inventors: Masashi Takahashi, Tomokazu Murakami, Hiroaki Ito, Isao Karube
  • IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD
    Publication number: 20080107448
    Abstract: To provide an image forming apparatus that performs image formation in accordance with a cleanerless system but less easily causes filming.
    Type: Application
    Filed: November 3, 2006
    Publication date: May 8, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Masashi Takahashi, Takeshi Watanabe, Minoru Yoshida
  • CHARGING DEVICE, IMAGE FORMING APPARATUS AND CHARGING METHOD
    Publication number: 20080107450
    Abstract: There is provided a charging technique in which the generation of ozone is suppressed and charging efficiency can be improved. A charging device includes a contact unit configured to include a magnetic brush coming in contact with a body to be charged, the contact unit including, as a magnetic particle forming the magnetic brush, the magnetic particle containing at least a particle having a negative electronegativity, and a voltage application unit configured to negatively charge the body to be charged by applying a specified bias voltage through the magnetic brush in the contact unit to the body to be charged.
    Type: Application
    Filed: November 8, 2006
    Publication date: May 8, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
  • Method and apparatus for symmetric-key decryption
    Patent number: 7359515
    Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length; generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: April 15, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe
  • Developing unit, image forming apparatus method that supplies inverse transfer preventing agent with inverse polarity
    Patent number: 7356291
    Abstract: An image forming apparatus of the invention holds a first developing agent of a first color and inverse transfer preventing agent, supplies the first developing agent with predetermined potential, supplies the first developing agent to an image portion of an image carrier, supplies the inverse transfer preventing agent with the first developing agent and electric charge of an inverse polarity, supplies the inverse transfer preventing agent to a non-image portion having a predetermined potential difference relative to an image portion, brings the image carrier into contact with a transfer object medium to which a second developing agent of a second color different from the first color is already transferred and transfers the first developing agent to the transfer object medium.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: April 8, 2008
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takao Izumi, Haruhiko Ishida, Masashi Takahashi
  • Apparatus and method for cleaning residual toner from drums in image forming apparatus
    Patent number: 7349652
    Abstract: An apparatus and method for cleaning a plurality of drums in an image forming apparatus includes applying a first bias to each of a plurality of disturbing members, each disturbing member associated with a corresponding drum of a plurality of drums. While performing an image forming operation wherein at least one of the plurality of drums is not use, the bias is changed of a disturbing member corresponding to at least one of the plurality of drums not used in performing the image forming operation from the first bias to a second bias different from the first bias.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: March 25, 2008
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takeshi Watanabe, Masashi Takahashi, Minoru Yoshida
  • Image forming apparatus and image forming method having a cleaner and a paper detecting unit
    Patent number: 7349643
    Abstract: An image forming apparatus that forms an image using a photoconductor body includes a switching unit which effects switching between a state in which a cleaner is operated for the photoconductor body, and a state in which the cleaner is not operated for the photoconductor body. A control unit is provided which controls a setting change of an image formation condition between a case where the cleaner is operated by the switching unit, and a case where the cleaner is not operated by the switching unit. The switching unit includes a detection unit which detects the kind of paper on which an image is formed, and the switching unit switches on/off the cleaner in accordance with a detection result of the detection unit.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: March 25, 2008
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takeshi Watanabe, Masashi Takahashi, Shoko Shimmura, Takashi Hatakeyama
  • Image forming apparatus and image forming method
    Publication number: 20080008489
    Abstract: It is an object of the invention to provide an image forming apparatus and an image forming method that can reduce generation of a waste toner. An image forming apparatus according to the invention includes an image bearing member on which a toner image is formed, a cleaner that transfers a toner image formed on the surface of the image bearing member and, then, removes a part of a toner remaining on the image bearing member and allows the remainder to pass as a passing toner, a passing toner amount detecting unit for detecting or estimating an amount of passing toner that passes the cleaner, and a cleaner control unit that sets, on the basis of an amount of passing toner detected by the passing toner amount detecting unit, a target value of the amount of passing toner and controls a cleaning operation by the cleaner.
    Type: Application
    Filed: July 5, 2006
    Publication date: January 10, 2008
    Applicants: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
  • Image forming apparatus, and toner recycle method
    Publication number: 20080008481
    Abstract: There is provided a technique in which when an image forming processing with toners of plural colors is performed, a residual toner on a transfer-receiving member to which toner images are transferred by plural image forming units is not discarded, but is reused as a black toner, and a deterioration in picture quality due to a change in color tone of the black toner is prevented.
    Type: Application
    Filed: July 5, 2006
    Publication date: January 10, 2008
    Applicants: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Masashi Takahashi, Minoru Yoshida, Takeshi Watanabe
  • Image forming apparatus and its cleaner unit, and cleaner unit replacement method of the image forming apparatus
    Publication number: 20080008498
    Abstract: There is provided an image forming apparatus in which occurrence of defective cleaning is prevented, replacement is easy, and occurrence of toner spillage can also be prevented. A cleaner unit of an image forming apparatus of the invention includes a cleaning member that is brought into contact with a toner bearing body in order to collect toner from the toner bearing body bearing the toner, a toner removal member to remove the toner from the cleaning member, and a waste toner storage part to store the removed toner, the cleaning member, the toner removal member and the waste toner storage part are integrally constructed into a unit structure, and the unit is constructed to be attachable to and detachable from the toner bearing body or a main body of the image forming apparatus.
    Type: Application
    Filed: July 5, 2006
    Publication date: January 10, 2008
    Applicants: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama
  • Color image forming apparatus with at least two stages of image forming units
    Patent number: 7317883
    Abstract: A color image forming apparatus in which a developing portion is provided with a mechanism capable of forming a developing agent image and recovering residual developing agent left remained on an image carrier, and an electrification portion of an image-forming unit disposed at a second stage further provided with a developing agent-removing member which is in contact with an electrifying member, thereby enabling a developing agent which is reversely transferred from a transferred image of a preceding stage and recovered by the electrification portion to be removed from the electrification portion.
    Type: Grant
    Filed: June 27, 2005
    Date of Patent: January 8, 2008
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Takeshi Watanabe, Masashi Takahashi, Mitsuaki Kouyama