Patents by Inventor Hiroshi Murasaki

Hiroshi Murasaki 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: 8439352
    Abstract: A one-way clutch is mounted on an outer periphery of a rotary shaft in a manner to place a clutch needle bearing in contact with the outer periphery of the rotary shaft. A rotary member is disposed on one side of the one-way clutch and engaged with the one-way clutch to be subjected to the rotation of the rotary shaft transmitted thereto. A retaining member is mounted on the outer periphery of the rotary shaft and located on the opposite side of the one-way clutch from the rotary member, while an urging unit is provided for urging the one-way clutch to abut against the retaining member.
    Type: Grant
    Filed: July 28, 2011
    Date of Patent: May 14, 2013
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Takeji Morikawa, Hiroshi Murasaki
  • Patent number: 8126379
    Abstract: The present invention provides a developing device which is capable of suppressing the generation of a fogging phenomenon and deposition of carrier particles to an electrostatic latent image carrier and developing the electrostatic latent image efficiently, the device includes a development sleeve and a magnet body onto which the sleeve is fitted, and using a two-component developer. An angular position which indicates the peak value of the magnetic flux density in the normal direction produced by a development pole of the magnet body is shifted downstream from the center position of the development pole in the direction of movement of the surface of a photosensitive member in a development region. The present invention also provides an image forming apparatus which can form high-quality images with reduced noise such as fogging by mounting the developing device.
    Type: Grant
    Filed: June 8, 2009
    Date of Patent: February 28, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Toru Hayase, Yuusuke Okuno, Shigeki Yamamoto, Kuniya Matsuura, Hiroshi Murasaki
  • Publication number: 20120043716
    Abstract: A one-way clutch is mounted on an outer periphery of a rotary shaft in a manner to place a clutch needle bearing in contact with the outer periphery of the rotary shaft. A rotary member is disposed on one side of the one-way clutch and engaged with the one-way clutch to be subjected to the rotation of the rotary shaft transmitted thereto. A retaining member is mounted on the outer periphery of the rotary shaft and located on the opposite side of the one-way clutch from the rotary member, while an urging unit is provided for urging the one-way clutch to abut against the retaining member.
    Type: Application
    Filed: July 28, 2011
    Publication date: February 23, 2012
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES, INC.
    Inventors: Takeji Morikawa, Hiroshi Murasaki
  • Publication number: 20090311011
    Abstract: The present invention provides a developing device which is capable of suppressing the generation of a fogging phenomenon and deposition of carrier particles to an electrostatic latent image carrier and developing the electrostatic latent image efficiently, the device comprising a development sleeve and a magnet body onto which the sleeve is fitted, and using a two-component developer. An angular position which indicates the peak value of the magnetic flux density in the normal direction produced by a development pole of the magnet body is shifted downstream from the center position of the development pole in the direction of movement of the surface of a photosensitive member in a development region. The present invention also provides an image forming apparatus which can form high-quality images with reduced noise such as fogging by mounting the developing device.
    Type: Application
    Filed: June 8, 2009
    Publication date: December 17, 2009
    Applicant: KONICA MINOLTA BUSINESS TECHNOLOGIES,INC.
    Inventors: Toru HAYASE, Yuusuke Okuno, Shigeki Yamamoto, Kuniya Matsuura, Hiroshi Murasaki
  • Patent number: 6038415
    Abstract: An image forming apparatus employs an image carrier (photoreceptor) cartridge having protective covers of which surface is coated with conductive shield in order to prevent frictional charging that will bring on sparking between a photoreceptor and covers. Further, the photoreceptor cartridge is equipped on its surface with an elastic member which is a foam body having a plurality of foam cells for catching foreign matter such as paper particles in order to prevent the foreign matter from damaging the surface of the photoreceptor. Moreover, the photoreceptor cartridge is also equipped with a flick member for flicking off toner deposited on a conductive brush in order to prevent the brush from becoming dirty. Owing to the above-mentioned construction, the image forming apparatus can avoid degradation in image quality.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: March 14, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Masayuki Nishi, Hiroshi Murasaki, Toru Matsui
  • Patent number: 6026259
    Abstract: An erasing device includes a sheet-like erasing member. The erasing member is supported by an electric charger in contact with the image bearing member for erasing a residual electric charge from the image bearing member. Preferably, the erasing member is supported by a supporting member which in turn is supported by the electric charger. Therefore, the erasing member can be disposed relative to the image bearing member with a greater precision without using any additional rigid member. Also, the image bearing member can be erased without any defect, which results in that the image bearing member is uniformly charged in the subsequent charging.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: February 15, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Hideo Yamaki, Koji Niizawa, Hiroshi Murasaki
  • Patent number: 5499090
    Abstract: An image forming apparatus has a toner recycling mechanism for effecting toner recycling. The image forming apparatus includes a developing unit accommodating developer for developing an electrostatic latent image formed on the surface of a photosensitive member, a cleaning unit for recovering developer remaining on the surface of the photosensitive member after development, and a toner recycling assembly. The toner recycling assembly includes a developer conveyor pipe through which the developer recovered by the cleaning unit is conveyed to the developing unit for recycling of toner contained in the developer, and also includes a developer supply or transport pipe for supplying the developer accommodated in the developing unit to either the developer conveyor pipe or the cleaning unit.
    Type: Grant
    Filed: June 10, 1993
    Date of Patent: March 12, 1996
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Noboru Ito, Hiroshi Murasaki, Hirokazu Yoshida, Fumio Masuda
  • Patent number: 5385801
    Abstract: This invention relates to a method of developing electrostatic latent images which comprises the steps of;mixing a developer including toners having a mean particle size of 3 to 20 .mu.m and resin-coated carriers with a large number of pores having a pore size distribution of 0.001 to 3 .mu.m and a mean pore size of 0.1 to 0.5 .mu.
    Type: Grant
    Filed: August 20, 1993
    Date of Patent: January 31, 1995
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Yoshihisa Terasaka, Junji Ohtani, Junji Machida, Tamotsu Shimizu, Hiroshi Murasaki, Hiroshi Mizuno
  • Patent number: 5311262
    Abstract: In an image forming apparatus accommodating a developing device, a developing roller 1 includes a magnet member 3 non-rotatably fixed and a sleeve 2 rotatably moved around the outer surface of the magnet member 3, powdery developers D held on the outer periphery of the sleeve 2 are brought into contact with a photosensitive member 10 to visualize an electrostatic latent image, and the magnet member 3 is provided with a magnetic pole portion N.sub.0 having first and second magnetic poles N.sub.1 and N.sub.2. The first and second magnetic poles N.sub.1 and N.sub.2 have the same polarities and are adjacent to each other and confront the photosensitive member 10. The powdery developers D include three developer parts, an upper developer D.sub.1, a middle developer D.sub.12 and a lower developer D.sub.2, which are successively retained on the outer surface of the sleeve 2 by the first and second magnetic poles N.sub.1 and N.sub.2. The upper developer D.sub.1 retained by the first magnetic pole N.sub.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: May 10, 1994
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tamotsu Shimizu, Hiroshi Murasaki, Masahiko Matsuura, Susumu Mikawa
  • Patent number: 5307128
    Abstract: A toner supplying device for supplying toner to a developing device in an electrophotographic image forming apparatus comprises a toner hopper for containing and feeding new toner, a recycle device for introducing toner from a cleaner which collects residual toner on an electrostatic latent image carrying member to an outlet of the hopper or the vicinity thereof, a toner agitating chamber opposed to the outlet of the hopper and an outlet of the recycle device, a toner agitating member disposed in the toner agitating chamber, and a toner feeder for feeding the toner from the toner agitating chamber to the developing device.
    Type: Grant
    Filed: August 27, 1991
    Date of Patent: April 26, 1994
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hiroshi Murasaki, Masanori Fujiwara
  • Patent number: 5206690
    Abstract: A developing device comprises a rotatable developing sleeve, a magnet member stationarily disposed inside the developing sleeve and a developer restricting member which restricts an amount of developer transported on a peripheral surface of the developing sleeve toward a developing region in accordance with rotation of the developing sleeve. The magnet member has a developing magnetic pole confronting the developing region, an identical polarity magnetic part which is provided between the developer restricting member and the developing magnetic pole and is formed of a plurality of adjacent magnetic poles of an identical polarity, and a magnetic pole which is provided between the identical polarity magnetic part and the developing magnetic pole for transporting the developer.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: April 27, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tamotsu Shimizu, Hiroshi Murasaki, Masahiko Matsuura, Susumu Mikawa
  • Patent number: 5140373
    Abstract: A developing apparatus is accommodated in an image forming apparatus to develop an electrostatic laten image formed on an electrostatic latent image support member, using two-component developer of toner and magnetic carrier. The developing apparatus is provided with a developing sleeve opposed to the electrostatic latent image support member, a magnetic roller disposed inside the developing sleeve to hold the carrier on a peripheral surface of the developing sleeve, a toner hopper accommodating the toner and having an opening at its one end, a toner supply roller rotatably disposed in the opening of the toner hopper and opposed to the developing sleeve, a bristle height adjusting member opposed to the developing sleeve on the downstream side of a developing region and on the upstream side of a toner supply region in a direction of movement of the carrier held on the peripheral surface of the developing sleeve.
    Type: Grant
    Filed: September 6, 1989
    Date of Patent: August 18, 1992
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Akihito Ikegawa, Hiroshi Mizuno, Hiroshi Murasaki, Kouichi Etou
  • Patent number: 5012285
    Abstract: A developing apparatus includes a photosensitive drum positioned in confronting relation to a developing sleeve. A toner accommodating tank is provided for supplying toner to the developing sleeve. The toner accommodating tank is divided into a small chamber and a supplementary chamber which are separated from one another by a partition which permits toner to be supplied from the supplementary chamber to the small chamber but which prevents the return of toner from the small chamber to the supplementary. A movable shutter selectively permits and prevents toner from being supplied from the supplementary chamber to the small chamber in accordance with operation of the apparatus.
    Type: Grant
    Filed: May 6, 1988
    Date of Patent: April 30, 1991
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama, Hiroshi Mizuno, Hiroshi Murasaki, Akihito Ikegawa, Kouichi Etou, Shuichi Nakagawa
  • Patent number: 4987452
    Abstract: An electrostatic latent image developing apparatus includes an agitating member accommodated in a casing, a roller member accommodated in a front of the casing, and a blade contacting under pressure with an outer circumferential portion of the roller member, which is arranged in the casing. Toner held on the outer circumferential portion of said roller member being supplied to develop an electrostatic latent image on the basis of rotation of the roller member while being regulated by the blade. The apparatus includes a partition member arranged between the roller member and the agitating member at an upper stream side of said blade corresponding to a rotary direction of the roller member. The casing has a space defined among the partition member, the blade, and the outer circumferential portion of the roller member.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: January 22, 1991
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Shuichi Nakagawa, Hiroshi Murasaki, Akihito Ikegawa, Kouichi Etou, Hiroshi Mizuno
  • Patent number: 4947212
    Abstract: An electrophotographic copying apparatus includes a main body, a developing system, removably mounted on the main body, provided with a developing device having the developing sleeve holding a carrier on the outer surface, and a toner cartridge having a toner supply roller which confronts the developing sleeve. A voltage-adjusting device adjusts the bias voltage to be supplied respectively to the developing sleeve and the toner supply roller depending on a toner color so as to generate a predetermined electric potential between the developing sleeve and the toner supply roller. The voltage adjusting device adjusts the bias voltage difference between the developing sleeve and the toner supply roller according to a saturation charge amount which is different depending on the toner color.
    Type: Grant
    Filed: May 18, 1988
    Date of Patent: August 7, 1990
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Akihito Ikegawa, Hiroshi Mizuno, Hiroshi Murasaki, Kouichi Etou
  • Patent number: 4924806
    Abstract: A developing apparatus is disposed adjacent to an electrostatic latent image support member in an image forming apparatus, and includes a rotatable developing sleeve confronting the electrostatic latent image support member, a magnetic roller disposed inside the developing sleeve for holding magnetic carrier on a peripheral surface of the developing sleeve, and a plurality of toner supply units confronting the developing sleeve for supplying toner to the developing sleeve. The magnetic roller accommodates a plurality of magnetic poles extending in a direction of its axis. Each toner supply unit is provided with a toner supply roller rotatable in contact with a magnetic brush held on the developing sleeve and a toner storing portion for storing the toner.
    Type: Grant
    Filed: January 19, 1988
    Date of Patent: May 15, 1990
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hiroshi Mizuno, Hiroshi Murasaki, Akihito Ikegawa, Kouichi Etou
  • Patent number: 4920916
    Abstract: A developing device including a toner support member for supporting toner on its surface, which is so provided as to confront an electrostatic latent image support member and a regulation member for forming a thin layer of the toner on the toner support member, which includes a curved member for pressing the toner support member and a support member for supporting the curved member such that an area S of a space satifies an equation: 0<S.ltoreq.0.15 mm.sup.2 wherein the space is defined in a radial plane of the toner support member and the curved member and is bounded by the toner support member, the curve member and a line drawn in parallel with a normal extending through a point of contact between the toner support member and the curved member and spaced a radius of curvature of the curved member from the normal at an upstream side of the normal in a direction of rotation of the toner support member.
    Type: Grant
    Filed: March 15, 1989
    Date of Patent: May 1, 1990
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hiroshi Mizuno, Toshiya Natsuhara, Yuji Enoguchi, Akihito Ikegawa, Masasi Yamamoto, Hiroshi Murasaki
  • Patent number: 4912511
    Abstract: A developing device including first and second developing sleeves rotatable in the same direction and being disposed adjacent to each other and magnets unrotatable and fixedly mounted in the respective developing sleeves. The first magnet mounted within the first developing sleeve has a first magnetic pole slightly downstream of the position at which the first developing sleeve and the second developing sleeve are closest to each other with respect to the rotational direction of the first developing sleeve. The second magnet mounted within the second developing sleeve has a second magnetic pole slightly upstream of the above-described closest position with respect to the rotational direction of the second developing sleeve.
    Type: Grant
    Filed: June 15, 1989
    Date of Patent: March 27, 1990
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventor: Hiroshi Murasaki
  • Patent number: 4851872
    Abstract: A developing device includes a developing sleeve provided rotatably at a side of an electrostatic latent image support member, a supply member for supplying developer to the developing sleeve, a bristle height regulating member which confronts an upper portion of the developing sleeve so as to adjust an amount of the developer transported to a developing region and a plurality of magnets provided in the developing sleeve. The magnetic poles of the magnets not only extend in an axial direction of the developing sleeve but are arranged in a circumferential direction of the developing sleeve. The magnetic poles include a weak magnetic pole disposed adjacent to the upper portion of the developing sleeve and two strong magnetic poles between which the weak magnetic pole is interposed. The strong magnetic poles have a polarity different from that of the weak magnetic pole.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: July 25, 1989
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hiroshi Murasaki, Hiroshi Mizuno, Akihito Ikegawa, Kouichi Etou
  • Patent number: 4819027
    Abstract: A developing apparatus includes a developing roller confronting an image support member for generating an electrostatic latent image on its surface, an accommodating tank for accommodating developing material therein, and a supply roller disposed to confront the developing roller so as to supply the developing material accommodated within the accommodating tank onto the developing roller, and is characterized in that a developing material supply width of the supply roller is smaller than the effective developing width of the developing sleeve.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: April 4, 1989
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Hiroshi Murasaki, Hiroshi Mizuno, Akihito Ikegawa, Kouichi Etou