Patents by Inventor Masashi Hirai

Masashi Hirai 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: 7801464
    Abstract: A surface of a discharge electrode of an ion generating device of the present invention, other than a surface in contact with a dielectric body, is coated with a protective layer made of a metal that is gold or a combination of gold and nickel. This allows the ion generating device to generate ions evenly and stably, and to have a longer life.
    Type: Grant
    Filed: August 4, 2008
    Date of Patent: September 21, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiaki Kagawa, Shogo Yokota, Katsumi Adachi, Masashi Hirai
  • Publication number: 20100183346
    Abstract: No covering layer is provided onto that abutting surface of an external heating belt which has contact with a cleaning member. Accordingly, a belt substrate is exposed and has contact with the cleaning member. This suppresses the occurrence of offset in a fixing device including (i) the external heating belt for having contact with the surface of the fixing roller so as to heat a fixing roller, and (ii) the cleaning member having contact with the external heating belt.
    Type: Application
    Filed: January 13, 2010
    Publication date: July 22, 2010
    Inventors: Toshiaki Kagawa, Susumu Murakami, Masashi Hirai, Atsushi Ide, Takashi Mukai
  • Publication number: 20100183345
    Abstract: A fixing device of the present invention includes: an external heating belt which is to contact with a surface of a fixing roller so as to heat up the fixing roller; and a cleaning member (a scraper and/or cleaning pad) which is to contact with the external heating belt. The cleaning pad which is impregnated with silicone oil is to contact with a surface of the external heating belt, thereby applying the silicone oil (release agent) to the surface of the external heating belt. This makes it possible to prevent generation of an offset.
    Type: Application
    Filed: January 13, 2010
    Publication date: July 22, 2010
    Inventors: Toshiaki KAGAWA, Susumu Murakami, Masashi Hirai, Atsushi Ide, Takashi Mukai
  • Publication number: 20100142988
    Abstract: In a fixing device including (i) an external heat belt which abuts against a surface of a fixing roller so as to heat the fixing roller and (ii) a cleaning member which abuts against the external heat belt, a fixing temperature, which is a surface temperature of the fixing roller during a fixing process, is set per group into which recording media to be subjected to the fixing process are divided according to their widths in a direction of a rotary axis of the fixing roller, in such a way that the fixing temperature is set to a lower temperature for a group of narrower widths. This makes it possible to prevent a reduction in releasability of the fixing roller caused by a material, which is scraped off from the external heat belt by the cleaning member and then adhered to the fixing roller, thereby preventing the high-temperature offset.
    Type: Application
    Filed: December 2, 2009
    Publication date: June 10, 2010
    Inventors: Toshiaki Kagawa, Susumu Murakami, Masashi Hirai, Atsushi Ide, Takashi Mukai
  • Patent number: 7725052
    Abstract: An ion generating device provided in an image forming apparatus of the present invention as a charging device for charging before a first transfer, a charging device for charging before a second transfer, or a charge device for charging an electrostatic latent image is arranged such that a discharge electrode can move with respect to a dielectric material and the relative positions of the discharge electrode and the dielectric material can be changed. This makes it possible to provide: a long-life ion generating device whose life has been extended by making effective use of a dielectric material; and an image forming apparatus including the ion generating device.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: May 25, 2010
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masashi Hirai, Kuniaki Nakano, Kazuaki Ishikawa
  • Publication number: 20090224634
    Abstract: A piezoelectric resonator device includes a base holding a piezoelectric resonator element and a lid bonded to the base in order to hermetically seal the piezoelectric resonator element held on the base. In addition, the region of bonding of the base to the lid is composed of at least a nickel-cobalt layer comprising nickel and cobalt, and a metal layer laminated on the nickel-cobalt layer, with the base and lid bonded by heat-melting using a metallic braze material.
    Type: Application
    Filed: May 25, 2007
    Publication date: September 10, 2009
    Inventors: Tatsuya Murakami, Masashi Hirai, Makoto Miyagawa, Akihiro Kanbara
  • Patent number: 7548709
    Abstract: A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred from a photoreceptor drum and (ii) moves a surface holding the toner image; and a secondary transfer belt that comes into contact with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes a cleaning unit that removes and collects toner from the surface of the intermediate transfer belt. The transfer unit also includes a power source for sequentially applying, to the secondary transfer belt, (i) a first voltage for generating an electric field that transfers normally-charged toner from the secondary transfer belt to the intermediate transfer belt and (ii) a second voltage for generating an electric field that transfers oppositely-charged toner from the secondary transfer belt to the intermediate transfer belt.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: June 16, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masashi Hirai, Kuniaki Nakano, Masanori Yamada, Takahiko Yoshida, Kazuaki Ishikawa, Hiroshi Tachiki, Toshio Yamanaka
  • Publication number: 20090097888
    Abstract: An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 ?m to 50 ?m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cm2 to 40 gf/cm2.
    Type: Application
    Filed: October 16, 2008
    Publication date: April 16, 2009
    Inventors: Masashi HIRAI, Mikio Kakui, Yoshiaki Masuda, Susumu Murakami, Kazuaki Ishikawa, Tomomi Tanaka
  • Publication number: 20090039244
    Abstract: A surface of a discharge electrode of an ion generating device of the present invention, other than a surface in contact with a dielectric body, is coated with a protective layer made of a metal that is gold or a combination of gold and nickel. This allows the ion generating device to generate ions evenly and stably, and to have a longer life.
    Type: Application
    Filed: August 4, 2008
    Publication date: February 12, 2009
    Inventors: Toshiaki Kagawa, Shogo Yokota, Katsumi Adachi, Masashi Hirai
  • Publication number: 20080246828
    Abstract: An ion generating device provided in an image forming apparatus of the present invention as a charging device for charging before a first transfer, a charging device for charging before a second transfer, or a charge device for charging an electrostatic latent image is arranged such that a discharge electrode can move with respect to a dielectric material and the relative positions of the discharge electrode and the dielectric material can be changed. This makes it possible to provide: a long-life ion generating device whose life has been extended by making effective use of a dielectric material; and an image forming apparatus including the ion generating device.
    Type: Application
    Filed: April 4, 2008
    Publication date: October 9, 2008
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Masashi HIRAI, Kuniaki NAKANO, Kazuaki ISHIKAWA
  • Patent number: 7257351
    Abstract: Providing a simply-arranged detaching/attaching mechanism and image forming device which allow a transfer supporter device to be detached/attached through a space formed by opening an outer covering, the device includes photosensitive drums, detachable/attachable transfer belt unit, and rail members supporting a transfer belt unit. Each of the rail members includes a rail groove guiding the transfer belt unit, notch and positioning hole determining the position of the transfer belt unit when the belt is in contact with the photosensitive drums, and notch and convex section determining the position of the transfer belt unit when the belt is detached from the photosensitive drums. The transfer belt unit support with respect to the main body of the image forming device, performed by the rail members, is released in response to the action of opening the side cover, so that the transfer belt unit is in a free state.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: August 14, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Tachiki, Masashi Hirai, Kohichi Yamauchi, Noritaka Okazaki, Fumio Shimazu
  • Patent number: 7251445
    Abstract: An image forming apparatus is provided with a latent image carrier for holding an electrostatic latent image, and an intermediate transfer member for temporally holding an image formed by visualizing the electrostatic latent image formed on the latent image carrier. The image forming apparatus performs image formation by superimposing a plurality of images on the intermediate transfer member so as to form a superimposing image, and transferring the superimposing image on a recording medium. The intermediate transfer member has a latent image holding property for holding the electrostatic latent image. An image formed by visualizing an electrostatic latent image formed on the intermediate transfer member is superimposed with the electrostatic latent image formed on the latent image carrier.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: July 31, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Masashi Hirai
  • Patent number: 7162192
    Abstract: A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.
    Type: Grant
    Filed: September 23, 2005
    Date of Patent: January 9, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masanori Yamada, Hiroshi Tachiki, Takahiko Yoshida, Masashi Hirai
  • Patent number: 7162178
    Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: January 9, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiki Takiguchi, Hiroshi Tachiki, Hirokazu Yamauchi, Hiroyuki Murai, Yoshiaki Masuda, Fumio Shimazu, Masashi Hirai
  • Patent number: 7139498
    Abstract: A tandem-type image forming apparatus for forming a multi-color image on a sheet transported by an endless transfer/transport belt, by sequentially laying on the sheet images developed in respective image forming stations. The apparatus includes: transfer rollers, each in contact through the transfer/transport belt with an image carrier provided in each image forming station; and a voltage applying device for applying a non-transfer bias voltage to only the transfer rollers that are in contact with the image carriers when a transfer process is not performed, the non-transfer bias voltage having the same polarity as a transfer bias voltage and being lower than the transfer bias voltage.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: November 21, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tamaki Mashiba, Masashi Hirai, Shigeru Watase
  • Publication number: 20060245782
    Abstract: A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred, at a primary transfer part, from a photoreceptor drum and (ii) rotates to move a surface holding the toner image; and a secondary transfer belt that comes into contact, at a secondary transfer part, with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes an intermediate transfer belt cleaning unit that removes and collects toner from the toner image holding surface of the intermediate transfer belt.
    Type: Application
    Filed: April 26, 2006
    Publication date: November 2, 2006
    Inventors: Masashi Hirai, Kuniaki Nakano, Masanori Yamada, Takahiko Yoshida, Kazuaki Ishikawa, Hiroshi Tachiki, Toshio Yamanaka
  • Patent number: 7085504
    Abstract: An image forming apparatus transfers a toner image formed on a photoconductor drum onto a sheet-like recording member while the sheet-like recording member is transported and attracted to a transfer belt, and comprises a jam handling control unit for detecting a transport fault of the sheet-like recording member, and for stopping the transport operation when the transport fault is detected. When the transport fault is detected in a section other than a fixing section, the jam handling control unit first causes the transport operation of the fixing section, and thereafter causes the transfer belt and the transport operation on the upstream side thereof to stop, and any sheet-like recording member remaining on the transfer belt so that the transport mechanism on the upstream side thereof is transported and stopped at the position spanning between the area of the fixing section and the area of the transfer belt.
    Type: Grant
    Filed: June 18, 2004
    Date of Patent: August 1, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuhiro Matsuyama, Yoshinobu Tateishi, Toshiya Mikita, Masashi Hirai, Toshio Yamanaka, Mitsuyoshi Terada, Yuji Nakagawa, Osamu Fujimoto
  • Publication number: 20060067745
    Abstract: A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.
    Type: Application
    Filed: September 23, 2005
    Publication date: March 30, 2006
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Masanori Yamada, Hiroshi Tachiki, Takahiko Yoshida, Masashi Hirai
  • Publication number: 20060008721
    Abstract: A color image forming black developer is provided which has a volume resistivity equal to those of the respective color developers of yellow, magenta and cyan and makes it possible to obtain an image of high image quality. The color image forming developer uses, as a coloring agent of toner of a black developer, a coloring agent containing a yellow coloring agent used for a yellow developer, a magenta coloring agent used for a magenta developer and a cyan coloring agent used for a cyan developer at a predetermined ratio.
    Type: Application
    Filed: July 6, 2005
    Publication date: January 12, 2006
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Masashi Hirai
  • Patent number: 6957022
    Abstract: A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and the transfer voltage applied onto the transfer belt is controlled based on a measurement result of the sensor.
    Type: Grant
    Filed: January 29, 2004
    Date of Patent: October 18, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masashi Hirai, Kohichi Yamauchi, Fumio Shimazu, Hiroshi Tachiki, Yuji Nakagawa