Patents by Inventor Isao Doi

Isao Doi 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: 5930565
    Abstract: An image forming apparatus includes a first conductive member, a photoelectric transfer layer mounted on the first conductive member, a surface electrode mounted adjacent to the photoelectric transfer layer but away from the first conductive layer, a dielectric layer opposed to the surface electrode, a second conductive member mounted on one surface of the dielectric layer away from the photoelectric transfer layer. A first power supply is provided for applying a voltage V.sub.c between first and second conductive members and a second power supply is provided for applying a voltage V.sub.b between the surface electrode and the second conductive member. The image forming apparatus satisfies following relationship:V.sub.b >(5.5)V.sub.c -(1+5.5/D.sub.p)(312+6.2D.sub.a)whereinV.sub.b : Voltage between surface electrode and second conductive member;V.sub.c : Voltage between first and second conductive members;D.sub.p : Thickness of photoelectric transfer layer; andD.sub.
    Type: Grant
    Filed: April 17, 1998
    Date of Patent: July 27, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Isao Doi, Keiko Momotani, Akihito Ikegawa
  • Patent number: 5881343
    Abstract: A contact charging device, in which a contact member for charging has a surface including a contact portion to be in contact with a charge receiving member as well as a charge contributing portion having a surface resistivity (.rho.s) of 1.times.10.sup.5 .OMEGA./.quadrature. or less. A maximum distance between the contributing portion and the charge receiving member is in a range from 5 .mu.m to 60 .mu.m. Alternatively, an electric power formed of a DC component is applied to the contact member to produce a potential difference in a range from 550 v to 750 v between the applied power and a potential at the surface of the charge receiving member before being charged by the electric power.
    Type: Grant
    Filed: July 8, 1997
    Date of Patent: March 9, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Keiko Momotani, Isao Doi, Akihito Ikegawa
  • Patent number: 5862443
    Abstract: An electrostatic recording apparatus 1 for forming an electrostatic image on an electric charge carrying member 2 comprises a photoelectric transfer member 14 spaced from the electric charge carrying member 2, a floating electrode 16 provided on a first surface of the photoelectric transfer member 14, an electric power supply 27 for applying a voltage between the second surface of the photoelectric transfer member 14 and the second surface of the electric charge carrying member 2, and an exposure device 8 for exposing a second surface of the photoelectric transfer member 14. The floating electrode 16 having an electric discharge terminal 18a close to the electric charge carrying member 2.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: January 19, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Akihito Ikegawa, Isao Doi, Keiko Momotani
  • Patent number: 5860046
    Abstract: The present invention provides a contact charging device, in which a contact member for charging is in contact with a charge receiving member for charging the same while suppressing charging irregularity. The contact member has a surface to be in contact with the charge receiving member. This surface has a volume resistivity in a range from 1.times.10.sup.4 .OMEGA..multidot.cm to 1.times.10.sup.10 .OMEGA..multidot.cm, and has a surface resistivity in a range from 1.times.10.sup.5 .OMEGA./.quadrature. to 1.times.10.sup.10 .OMEGA./.quadrature..Alternatively, the contact member has a surface to be in contact with the charge receiving member. This surface of the contact member has a surface hardness which provides a scratch width of 1 .mu.m or less under scratch hardness test.
    Type: Grant
    Filed: July 8, 1997
    Date of Patent: January 12, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Akihito Ikegawa, Keiko Momotani, Isao Doi
  • Patent number: 5790925
    Abstract: An image forming apparatus of the present invention comprises an image carrying member 2, a photosensitive member 9, a first voltage applying means 13, and an exposure means 5. The image carrying member 2 has an insulating layer 25 formed on a first conductive layer 23. The photosensitive member 9 has a photosensitive layer 93 formed on a second conductive layer 92. The photosensitive member 9 is supported so that the photosensitive layer 93 is opposed to the insulating layer 25 of the image carrying member 2. The first voltage applying means 13 applies a voltage between the first conductive layer 25 and the second conductive layer 92. A pattern-like surface electrode layer 98 is formed on the surface of the photosensitive layer 93 opposed to the image carrying member 2. A second voltage applying means 14 applies a bias voltage to the surface electrode layer 98.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: August 4, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Isao Doi, Keiko Momotani, Akihito Ikegawa
  • Patent number: 5774169
    Abstract: An image forming apparatus having an insulated member disposed adjacent to a photosensitive member, a scanner exposing an image on the photosensitive member in a direction perpendicular to the direction of movement of the insulated member while voltage is applied between the photosensitive member and the insulated member so as to provide a charge on the insulated member surface corresponding to the optical exposure image. The exposure position exposed by the scanner is changed in the direction of movement of the image-bearing member for each scan.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: June 30, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Akihito Ikegawa, Isao Doi, Masashi Yamamoto, Seishi Ojima, Keiko Nagayasu
  • Patent number: 5652649
    Abstract: In electrophotographic image forming, there are provided a charging device and an image forming apparatus provided with the charging device for forming an image including no or less image noise by sufficiently suppressing generation of image memory due to untransferred residual developer. The charging device has, for example, a charging brush formed of a roller and a strip-like fiber member having a plurality of piles wound therearound. The brush satisfies a condition of 0.7s<d<1.5s where d(mm) is a wound margin of the strip-like fiber member, and s(mm) is an average distance between the piles in a width direction of the fiber strip member.
    Type: Grant
    Filed: November 7, 1995
    Date of Patent: July 29, 1997
    Assignees: Minolta Co., Ltd, Toeisangyo Co., Ltd.
    Inventors: Akihito Ikegawa, Keiko Nagayasu, Isao Doi
  • Patent number: 5572294
    Abstract: A contact charging device which charges the surface of an electrostatic latent image carrying member rotating at a high speed by contacting a charging member to the surface of the image carrying member. The charging member has a conductive substrate, a conductive elastic layer superimposed over the conductive substrate and having a JIS-A hardness of 30.degree. or greater, and a conductive resin layer superimposed over the conductive elastic layer and having a 10% elongation load of not more than 700 gf on a 1 cm wide section.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: November 5, 1996
    Assignee: Minolta Co., Ltd.
    Inventors: Izumi Osawa, Isao Doi, Seishi Ojima, Yoshihiro Uchimoto
  • Patent number: 5557372
    Abstract: A contact charging device having a charging member including a rotatable support member and a plurality of flexible films. One end of each the films is attached to the support member, and a free end of each the films is in contact with surface of the charge-receiving member for charging the surface of a charge-receiving member.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: September 17, 1996
    Assignee: Minolta Co., Ltd.
    Inventors: Seishi Ojima, Isao Doi, Izumi Osawa
  • Patent number: 5557375
    Abstract: An image forming apparatus that includes a positioning device for selectively positioning a contact-charging member at a charging position where the contact-charging member contacts a photosensitive carrier at a first region or at a cleaning position where the contact-charging member contacts the carrier at a second region. A contact charger apparatus for charging a carrier for carrying an electrostatic latent image, said contact charger apparatus that includes a voltage source coupled to a contact charger for applying a voltage to said carrier; and a contact charger cleaner for changing a contact area between said contact charger and said carrier to effect cleaning of said contact charger.
    Type: Grant
    Filed: August 9, 1995
    Date of Patent: September 17, 1996
    Assignee: Minolta Co., Ltd.
    Inventors: Keiko Nagayasu, Akihito Ikegawa, Isao Doi, Masashi Yamamoto
  • Patent number: 5536610
    Abstract: The present invention provides a photosensitive member composed of a photosensitive layer and a surface protective layer on an electrically substrate in this order, in which the surface protective layer comprises an amorphous carbon layer which has a specified ratio of absorptivity coefficients of infrared absorption peaks in infrared absorption spectrum.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: July 16, 1996
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Seishi Ojima, Kenji Masaki, Takeshi Kakutani, Toshiyuki Kobayashi, Isao Doi, Izumi Osawa
  • Patent number: 5396317
    Abstract: This invention provides an image forming apparatus comprising:a photosensitive member having an amorphous carbon layer on a surface thereof; anda developing device accommodating a toner for developing an electrostatic latent image formed on the surface of the photosensitive member, the toner including magnetic particles each of which has at least either of octahedron shape and irregular shape.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: March 7, 1995
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Izumi Osawa, Kenji Masaki, Isao Doi, Shuji Iino
  • Patent number: 5330873
    Abstract: This invention relate to a production method of a photosensitive member having an organic photosensitive layer and a surface protective layer in this order on an electrically conductive substrate comprising;a first step of forming the organic photosensitive layer on the electrically conductive substrate,a second step of eliminating an outermost surface portion of the organic photosensitive layer, anda third step of forming the surface protective layer under vacuum conditions on the organic photosensitive layer.
    Type: Grant
    Filed: January 14, 1993
    Date of Patent: July 19, 1994
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Isao Doi, Kenji Masaki, Shuji Iino, Izumi Osawa
  • Patent number: 5308727
    Abstract: The present invention relates to a photosensitive member comprising:an electrically conductive substrate,an organic photosensitive layer formed on or over the electrically conductive substrate, the organic photosensitive layer comprising an antioxidant and/or a charge transporting material, anda surface protective layer formed on the organic photosensitive member,characterized by that the antioxidant and/or the charge transporting material is (are) contained in a more increased quantity with being closer to the interface between the surface protective layer and the organic photosensitive layer.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: May 3, 1994
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Izumi Osawa, Isao Doi
  • Patent number: 5242773
    Abstract: The present invention relates to a photosensitive layer comprising:a substrate;a photosensitive layer formed on the substrate;a surface protective layer formed on the photosensitive layer, the surface protective layer being a deposited layer formed by a vacuum vapor deposition method to have no less than 400/cm.sup.2 solvent-penetrable spots formed in its thickness direction.
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: September 7, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Shuji Iino, Kenji Masaki, Seishi Ojima, Isao Doi, Izumi Osawa
  • Patent number: 5242776
    Abstract: The present invention relates to a photosensitive member in which a vacuum thin layer is formed as a surface protective layer on or over the roughened surface of the photosensitive layer.
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: September 7, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Isao Doi, Seishi Ojima, Kenji Masaki, Shuji Iino, Izumi Osawa
  • Patent number: 5232799
    Abstract: This invention relates to a photosensitive member comprising a conductive substrate; an organic photosensitive layer formed on the conductive substrate, and containing a solvent at a content of 1,500 ppm or less; and a surface protective layer formed on the organic photosensitive layer, which is composed of an amorphous hydrocarbon having an absorptivity coefficient of 400 to 5,000 cm.sup.-1 with respect to light of 450 nm wavelength.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: August 3, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Izumi Osawa, Shuji Iino, Isao Doi, Kenji Masaki
  • Patent number: 5198317
    Abstract: The present invention relates to a photosensitive member comprising a conductive substrate; an organic photosensitive layer formed on the conductive substrate, and containing a solvent at a content of 2,500 ppm or more; and a surface protective layer formed on the organic photosensitive layer, which is composed of an amorphous hydrocarbon having an absorptivity coefficient of 400 to 5,000 cm.sup.-1 with respect to light of 450 nm wavelength.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: March 30, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Izumi Osawa, Shuji Iino, Isao Doi, Kenji Masaki
  • Patent number: 5155002
    Abstract: An image forming method comprising the steps of forming an electrostatic latent image on a photosensitive member having a surface layer containing binder resin and photosensitive material dispersed in the binder resin, supplying charged toner particles to the above electrostatic latent image to form a toner image on the above photosensitive member, conveying paper toward the surface of the above photosensitive member to engage the paper with the above toner image, and transferring the toner image formed on the photosensitive member to the above paper, the relationship among the normal velocity (N) [mm/sec] of the paper which is defined by the formula of (v) sin .theta., and the thickness (T) [.mu.m] and the Vickers hardness (V) of the surface layer of the above photosensitive member satisfying the condition of T.multidot.(V/N).sup.0.
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: October 13, 1992
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Izumi Osawa, Seishi Ojima, Kenji Masaki, Shuji Iino, Isao Doi
  • Patent number: 5139906
    Abstract: A photosensitive medium which comprises an electroconductive substrate, an organic photosensitive layer formed on the substrate and a surface protective layer formed on the photosensitive layer and including amorphous hydrocarbon. The surface protective layer has a first region overlaying the photosensitive layer and a second region overlaying the first region. The second region of the surface protective layer includes amorphous hydrocarbon having a light absorption coefficient at a wavelength of 450 nm which is greater than 10,000 cm.sup.-1, and the first region of the surface protective layer includes amorphous hydrocarbon having a light absorption coefficient which is relatively smaller than that of the second region of the surface protective layer.
    Type: Grant
    Filed: November 29, 1990
    Date of Patent: August 18, 1992
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Isao Doi, Izumi Osawa, Shuji Iino, Kenji Masaki