Patents by Inventor Shigeki Nakajima

Shigeki Nakajima 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: 6112037
    Abstract: A color image forming apparatus includes a carrier belt which runs along a transport path of a recording medium to transport the recording medium. A number of image-forming sections are aligned in the transport path. Each of the plurality of image-forming sections forms a toner image of a corresponding color included in an image signal. A plurality of transfer units are provided, with each being disposed to oppose a corresponding one of the number of image-forming sections. Each of the number of transfer units transferring the toner image of the corresponding color to the recording medium. A fixing unit is provided that fixes the toner image to the recording medium. A controller is provided that detects a number of colors in the image signal. The controller sets one set of speeds from a plurality of different sets of speeds in accordance with the number of colors.
    Type: Grant
    Filed: August 11, 1999
    Date of Patent: August 29, 2000
    Assignee: Oki Data Corporation
    Inventors: Masato Nagata, Hisao Ono, Yoshiharu Momiyama, Noboru Otaki, Atsushi Kurabayashi, Shinichi Murakami, Yoshitatsu Okiyama, Mikio Yamamoto, Shigeki Nakajima, Masato Sakai, Fumiaki Yoshida, Norio Ebata, Makoto Yabuki, Makoto Otake
  • Patent number: 6061537
    Abstract: An electrophotographic recording apparatus has a plurality of image-forming sections and records a full color image. The apparatus includes a chassis and two plate-like supporting members oppositely disposed on the chassis. The two supporting members extend parallel with each other. The supporting members has means which support components of the plurality of image-forming sections between the two supporting members so that the components are placed in position relative to each other.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: May 9, 2000
    Assignee: Oki Data Corporation
    Inventors: Shigeki Nakajima, Atsushi Kobayashi
  • Patent number: 6021292
    Abstract: A toner cartridge includes a hollow outer body, hollow inner body, and partition. The inner body is inserted into an outer body and slidably rotatable relative to the outer body. A partition is supported in the outer body and is slidable relative to the outer body in a longitudinal direction of the cartridge. The partition is at a first position substantially adjacent a longitudinal end when the inner body is at a closing position. The partition is moved to a second position after the inner body has been rotated to the opening position, thereby defining a residual toner accommodating space between the partition and the longitudinal end of the outer body. An agitating member may be provided in which a residual toner accommodating space is formed therein. The residual toner removed from a photoconductive drum is collected in a first toner receiving section. The residual toner is then carried by a screw conveyor to one side of the print process cartridge.
    Type: Grant
    Filed: March 10, 1999
    Date of Patent: February 1, 2000
    Assignee: Oki Data Corporation
    Inventors: Shigeki Nakajima, Takashi Wakana
  • Patent number: 5983042
    Abstract: A color image forming apparatus provides the prolonged life of the photosensitive drums, carrier belt, and toner of the respective colors and improves the quality of the printed color image. A carrier belt transports a recording medium placed thereon so that the recording medium passes through a plurality of printing mechanisms which print images of different colors on the recording medium in superposition. Each printing mechanism prints an image of a corresponding color. The printing mechanism is adapted to be moved into its operative position where the photosensitive drum of the printing mechanism is in contact with the carrier belt to print the image on the recording medium, and into its non-operative position where the photosensitive drum of the printing mechanism is not in contact with the carrier belt.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: November 9, 1999
    Assignee: Oki Data Corporation
    Inventors: Masato Nagata, Hisao Ono, Yoshiharu Momiyama, Noboru Otaki, Atsushi Kurabayashi, Shinichi Murakami, Yoshitatsu Okiyama, Mikio Yamamoto, Shigeki Nakajima, Masato Sakai, Fumiaki Yoshida, Norio Ebata, Makoto Yabuki, Makoto Otake
  • Patent number: 5975518
    Abstract: A paper feeding mechanism holds a stack of print paper in pressure contact with a paper pick-up roller. The paper pick-up roller feeds the print paper out of the tray one page at a time when the paper pick-up roller is rotated. The paper feeding mechanism has first and second supporting surfaces. The first supporting surface holds the stack of print paper from behind a back surface of the print paper. The first supporting surface is at a second angle .theta. 2 with the horizontal direction such that the print paper slides along the first supporting surface to the second supporting surface with the aid of the gravity of the print paper. The second supporting surface supports the stack of print paper thereon. The second supporting surface is inclined at a first angle .theta. 1 with a horizontal direction such that a leading edge of each page of the print paper abuts the second supporting surface and slides toward the rotating paper pick-up roller with the aid of a gravity of the print paper.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: November 2, 1999
    Assignee: Oki Data Corporation
    Inventors: Takashi Wakana, Shigeki Nakajima
  • Patent number: 5963815
    Abstract: An amorphous silicon conductive film on a semiconductor wafer is treated with hydrofluoric acid to remove a natural oxide film therefrom, and then a very thin oxide film is formed on the semiconductor wafer. Thereafter, a silane gas is used to form a nucleating film, followed by annealing to cause the surface of the conductive film be roughened. The very thin oxide film is formed in a thickness of 0.5 angstroms to 20 angstroms. The very thin oxide film is alternatively formed either by treatment with an aqueous hydrofluoric acid solution or by flushing treatment. Thus, a roughened surface having a satisfactory roughness is uniformly formed on the surface of a conductive film on a semiconductor wafer.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: October 5, 1999
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Ryoden Semiconductor System Engineering Corporation
    Inventors: Yoshihiko Okamoto, Tadashi Yoshida, Hiroshi Ohnishi, Kenichi Hanaoka, Shigeki Nakajima, Junichi Tsuchimoto
  • Patent number: 5956556
    Abstract: An electrophotographic printer has a toner recycling mechanism with a belt conveyor that transports toner from a toner collection chamber, in which toner removed from the photosensitive drum of the printer is collected, to a toner delivery chamber, from which toner is returned to the developing unit of the printer. The belt conveyor is disposed in a channel that loops around the ends of roller shafts in the printer, and does not increase the width of the printer. The toner recycling mechanism is easily assembled, and can be driven without motion irregularities.
    Type: Grant
    Filed: June 15, 1998
    Date of Patent: September 21, 1999
    Assignee: Oki Data Corporation
    Inventors: Shigeki Nakajima, Atsushi Kobayashi
  • Patent number: 5737664
    Abstract: When the surface temperature of a heating roller exceeds a predetermined temperature, bearings that rotatably support the heating roller melt. Thus, a pressuring roller causes the heating roller to move toward a temperature detecting device. Thus, the heating roller comes in contact with the temperature detecting device. Consequently, when a defect takes place, the warm-up time after the temperature detecting device works until the power to the heater is shut off can be reduced. In addition or in the alternative, an electrode plate has edges electrically contacting and connecting the heater in the heating roller and a power supply. As the heating roller moves, electrical contact between the heater and the electrode plate is broken and the power from the power supply to the heater is disconnected. As a result, an electrophotographic printing apparatus can be prevented from getting defective, thereby improving the reliability thereof.
    Type: Grant
    Filed: June 15, 1995
    Date of Patent: April 7, 1998
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Masahiro Fukuda, Shigeki Nakajima, Koji Morimoto, Takashi Wakana, Takao Uchida, Naoki Sunaga
  • Patent number: 5722019
    Abstract: A toner cartridge includes an outer pipe, inner pipe inserted into the outer pipe, and cap fitted over the inner pipe. The outer pipe and inner pipe are of a long, hollow cylinder shape and are formed with a plurality of first and second openings, respectively, therein aligned longitudinally thereof. The inner pipe has at one end thereof a toner-filling opening and an annular flange eccentric with respect to the hollow cylinder, and at the other end thereof a knob that closes the longitudinal end of the hollow cylinder and abuts the outer pipe. The first openings are not aligned with the second openings when the inner pipe is at a first rotational position and are aligned when the inner pipe is at a second rotational position. A sealing member is mounted to the inner pipe encircling the second openings and has third openings aligned with the second openings.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: February 24, 1998
    Assignee: Oki Data Corporation
    Inventor: Shigeki Nakajima
  • Patent number: 5419544
    Abstract: A paper cassette comprises a paper stack tray provided on a cassette body, a stack tray locking mechanism for locking the paper stack tray and releasing the lock when the cassette is inserted into the cassette receptacle, and a first restoring member for pushing the paper stack tray toward a supply roller and bringing the paper when the lock of the stack tray locking mechanism is released. The stack tray locking mechanism comprises a pivot member provided on the cassette body such that the pivot member is free to pivot, a locking member which engages with the pivot member, and engages the paper stack tray in the locked position, and a second restoring member for pushing the pivot member in such a direction that the pivot member comes in contact with the supply roller so as to engage the locking member with the paper stack tray.
    Type: Grant
    Filed: January 12, 1994
    Date of Patent: May 30, 1995
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Ichiro Ono, Masahiro Fukuda, Shigeki Nakajima
  • Patent number: 5307134
    Abstract: An electrophotographic apparatus for providing a thermally fixed toner image on a recording medium and wherein the fixing temperature can be selectively canceled. The apparatus is of the type including: an image forming unit for forming a toner image to be printed and for then transferring the toner image onto a recording medium, a feed mechanism for feeding a recording medium supplied via one of at least two guide paths to the image forming unit, a fixing unit for thermally fixing the transferred toner image on the recording medium, and a temperature control unit for setting a fixing temperature for the fixing unit. A controller is provided to determine the particular guide paths used to supply the recording medium and to command the temperature control unit to set a fixing temperature in accordance with the determined guide path.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: April 26, 1994
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shigeki Nakajima, Koji Morimoto
  • Patent number: 5289249
    Abstract: An electrophotographic printer which includes a developing device for developing an electrostatic latent image formed on the surface of a photoconductor by adhering a developer thereto, a cleaning device for collecting the developer which remains on the photoconductor for reuse after the transference of the developer, and a toner recycling route for flowing the collected developer from the cleaning device back to the developing device by gravity. The photoconductor is exposed to a light source prior to the developer being applied to the surface of the photoconductor.
    Type: Grant
    Filed: May 6, 1992
    Date of Patent: February 22, 1994
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Mikio Yamamoto, Minoru Isobe, Yoshiharu Momiyama, Shigeki Nakajima, Hisao Ono
  • Patent number: 5280324
    Abstract: A detachable toner cartridge for use in an electrophotographic printer includes an outer cylinder and an inner cylinder contacting each other and having respective toner discharge outlets that can be overlapped with each other by turning the inner cylinder relative to the outer cylinder so as to discharge toner. The inner cylinder is pressed against the outer cylinder in the circumferential direction to bring the cylinders into close contact to prevent toner leakage. The toner cartridge does not require so high accuracy in manufacturing thereof.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: January 18, 1994
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hisao Ono, Yukio Ota, Hiroshi Kikuchi, Yoshiharu Momiyama, Shigeki Nakajima
  • Patent number: 5264900
    Abstract: A developing device suitable for use in an electrophotographic recording apparatus includes either a toner stirring portion arranged in a toner hopper portion, the toner stirring portion being provided with a portion for varying toner conveying speed, or in the toner a toner stirring and moving means provided in a toner cartridge. A printing irregularity does not occur on a printing paper even if the printing is performed at the state where the amount of toner, which is collected in the toner hopper portion, is too reduced to sufficiently cover the toner hopper stirring portion.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: November 23, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Yoshiharu Momiyama, Shigeki Nakajima, Yukio Ota
  • Patent number: 5235389
    Abstract: A toner cartridge employed in an electrophotographic printer and capable of attachment to or detachment from the electrophotographic printer. The toner cartridge includes a stirring member (4) which touches the inner wall of the cartridge (100) to reliably stir the toner contained in the cartridge (100). The stirring member (4) is rotatable and is interlocked with a gear (5) which is rotated by an external drive force.
    Type: Grant
    Filed: November 29, 1991
    Date of Patent: August 10, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hiroshi Kikuchi, Yukio Ota, Yoshitomo Koga, Kazuki Obara, Yoshiharu Momiyama, Shigeki Nakajima, Kiyoshi Matsuda, Hisao Ono
  • Patent number: 5216462
    Abstract: A toner residual amount detecting mechanism comprises a stirring device and a photosensor. The photosensor has a protrusion, and rotates together with a stirring shaft while the protrusion contacts with a pin planted on the stirring shaft. The stirring device rotates by its gravity when it reaches a top dead point thereof. The stirring device also includes a magnetic rotor attracted by a permanent magnet in a sensor lever to thereby turn the sensor lever about the fulcrum of the sensor lever to a predetermined position. The sensor lever is stopped by a stopper when the stirring device reaches the bottom dead point thereof. The photosensor cannot detect light when the sensor lever is positioned at the bottom dead point since the light is intercepted by the sensor lever but can detect the light when the sensor lever reaches the predetermined position. The mechanism can inform an operator of a toner supply time since the photosensor operates depending on the resistance of toner against the stirring device.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: June 1, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shigeki Nakajima, Masato Takano, Yoshiharu Momiyama, Hiroshi Kikuchi, Yukio Ota
  • Patent number: D332962
    Type: Grant
    Filed: December 28, 1989
    Date of Patent: February 2, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Hiroshi Kikuchi, Hisao Ono, Yoshiharu Momiyama, Shigeki Nakajima
  • Patent number: D354980
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: January 31, 1995
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shigeki Nakajima, Yukio Ota, Yoshiharu Momiyama
  • Patent number: D356815
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: March 28, 1995
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shigeki Nakajima, Yukio Ota, Yoshiharu Momiyama
  • Patent number: D389860
    Type: Grant
    Filed: March 5, 1996
    Date of Patent: January 27, 1998
    Assignee: Oki Data Corporation
    Inventors: Shigeki Nakajima, Yukio Ota, Yoshiharu Momiyama