Patents by Inventor Yoshihiro Murasawa

Yoshihiro Murasawa 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: 5589920
    Abstract: An image forming apparatus includes an image carrier for carrying an image, and a transfer medium bearing member for bearing and conveying a transfer medium to a transfer unit of said image carrier. The transfer medium bearing member is able to bear multiple transfer media concurrently. The apparatus includes transfer device for transferring the image of the image carrier onto the transfer medium borne on the transfer medium bearing member in the transfer unit, and a plurality of transfer media capable of being borne on the transfer medium bearing member concurrently, wherein in consecutively transferring the image onto the transfer media of the number not divisible by the maximum sheet bearing number by which said transfer medium bearing member is capable of bearing the transfer media concurrently.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: December 31, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takahiro Kubo, Masashi Suda, Yoshihiro Murasawa, Takashi Hasegawa, Satoshi Tamura, Hisashi Fukushima, Takeshi Menjo
  • Patent number: 5589926
    Abstract: An apparatus for forming color toner images on an electrophotographic photosensitive drum and transferring the color toner images onto a transfer drum, is provided with plural color development devices positioned along the rotating direction of the photosensitive drum and opposed thereto, and the above-mentioned transfer drum of a peripheral length is capable, in the rotating direction of the photosensitive drum, of simultaneously supporting two images of a maximum length L to be formed, wherein a relation:d.sub.p =(2.pi.R-2L)/2>d.sub.s .gtoreq.2r+(V.sub.p /V.sub.s).pi.ris substantially satisfied among the peripheral length A of the transfer drum, radius R and peripheral speed V.sub.p of the transfer drum, radius r and peripheral speed V.sub.s of the developing rollers of the development means, distance d.sub.p of two images on the transfer drum, and distance d.sub.s of the developing rollers in the rotating direction of the photosensitive drum.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: December 31, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshihiro Murasawa, Hisashi Fukushima, Takeshi Menjo, Takashi Hasegawa
  • Patent number: 5121163
    Abstract: An image forming apparatus includes a movable image bearing member; a device for forming an image on the image bearing member, the image forming device including a developing device for forming a toner image on the image bearing member; a transfer device for transferring a toner image onto a transfer material, the transfer device including transfer material carrying member for carrying the transfer material to an image transfer station; a toner content detector for detecting toner content, the detector detecting toner content using the toner deposited on the image bearing member by the developing device; and a controller for controlling the toner content in the developing device in accordance with an output of the detector; wherein the toner for the detection is deposited on such a portion of the image bearing member as to be out of contact from the transfer material carrying member.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: June 9, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masanori Muramatsu, Yoshihiro Murasawa, Yuji Hasegawa
  • Patent number: 5036364
    Abstract: An image forming apparatus is provided with an electrostatic latent image forming member disposed on an image bearing member and developing member for developing the latent image. A developer carring member is rotatable in a first direction to carry a developer to a developing zone to develop the electrostatic latent image and is rotatable in an opposite direction for a predetermined period when it does not develop the latent image. A stationary magnet is disposed in the developer carrying member. The magnet has a first magnetic pole and a second magnetic pole having the same magnetic polarity at positions downstream of the developing zone with respect to the first direction. The first and second magnetic poles are disposed adjacent to each other, with the second magnetic pole disposed downstream of the first magnetic pole with respect to the first direction.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: July 30, 1991
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshihiro Murasawa
  • Patent number: 4982239
    Abstract: An image forming apparatus having a moving image bearing member on which a latent image is formed and developed into a visible image and a reciprocating cleaning device, such as a blade or roller, arranged to press against the surface of the image bearing member and reciprocate in a direction transverse to its movement. A suitable expendient is provided to change the reciprocating motion, e.g. by stopping it, slowing it or increasing its stroke, during latent image formation to minimize vibrations and resultant image blurs while providing good cleaning.
    Type: Grant
    Filed: August 3, 1988
    Date of Patent: January 1, 1991
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nobuyuki Kume, Yoshihiro Murasawa
  • Patent number: 4860048
    Abstract: An image forming apparatus includes movable image bearing member, a first charger means for charging the image bearing member, first electrostatic latent image forming device for forming a first electrostatic latent image in accordance with image information on the image bearing means charged by the first charger, first developing device for developing the first electrostatic latent image, a second charger for re-charging the image bearing member, second electrostatic latent image forming device for forming a second electrostatic latent image in accordance with image information on the image bearing member recharged by the second charger, second developing device for developing the second electrostatic latent image, a dector for detecting a surface potential of the image bearing member, the detector detecting at least the surface potential at that portion of the latent image formed on the image bearing member by the first latent image forming device which is developed, after the portion is charged by the seco
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: August 22, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Itoh, Yoshihiro Murasawa, Atsushi Takeda, Hiroaki Tsuchiya, Kimio Nakahata
  • Patent number: 4814886
    Abstract: An image processing process forms a plural microdots for each pixel, and the number of microdots increases only in one direction for representing a higher density, thereby achieving an improved linearity in the density levels without sacrificing the resolving power.
    Type: Grant
    Filed: June 28, 1988
    Date of Patent: March 21, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsukasa Kuge, Takahiro Inoue, Yasushi Sato, Akio Suzuki, Yoshihiro Murasawa, Hiroshi Sasame, Jun Asai
  • Patent number: 4719489
    Abstract: A recording apparatus includes a fixing device for fixing an image to be recorded, on a recording material selectively under a first fixing condition or a second fixing condition; a feeder for feeding the recording material to said fixing means selectively in a first recording material feed mode or a second recording material feed mode which is different from said first recording material feed mode; and a controller, responsive to the change of the recording material feed modes, for bringing said fixing means under the first fixing condition upon the first recording material feeding mode and to a second fixing condition, which is different from the first fixing condition, upon the second recording material feed mode.
    Type: Grant
    Filed: June 16, 1987
    Date of Patent: January 12, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaharu Ohkubo, Yasumasa Ohtsuka, Jun Asai, Yoshihiro Murasawa
  • Patent number: 4626096
    Abstract: An image forming apparatus is used in conjunction with a signal generator for producing an image signal representing an image to be recorded. The apparatus includes a device for forming a visible image with visible material on an image bearing member. The image is represented by the image signal produced by the signal generator. A time signal is also generated by a time signal generator and a measuring circuit measures the time signal so generated as a function of the production off the image signal by the image signal generator. Finally, a warning signal that indicates insufficiency of supply of the visible material for forming an image properly by the image forming device is produced on the basis of measurement of the time signal by the measuring circuit.
    Type: Grant
    Filed: March 29, 1985
    Date of Patent: December 2, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasumasa Ohtsuka, Jun Asai, Yoshihiro Murasawa, Hiroshi Sasame, Masaharu Ohkubo
  • Patent number: 4579082
    Abstract: A developing apparatus wherein a thin layer of a non-magnetic developer is formed on a developer carrying member includes a developer container for containing a mixture of non-magnetic developer and magnetic particles; a device disposed adjacent to a non-magnetic developer outlet of developer container with a clearance with respect to a surface of developer carrying member, for regulating supply of the non-magnetic developer to developer carrying member surface; magnetic field generating device, disposed across developer carrying member with respect to regulating device, for forming a magnetic brush of the magnetic particles at the upstream side of regulating device with respect to movement of developer carrying member to confine the magnetic particles within developer container.
    Type: Grant
    Filed: August 29, 1983
    Date of Patent: April 1, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshihiro Murasawa, Kimio Nakahata
  • Patent number: 4568176
    Abstract: A method for maintenance of an image forming device having an image forming member which forms visible images from electrostatic latent images comprises maintaining the image forming ability of said image forming member by contacting the surface of said image forming member with an ion-exchange material.
    Type: Grant
    Filed: May 18, 1983
    Date of Patent: February 4, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yoshihiro Murasawa
  • Patent number: 4563694
    Abstract: An image information recording apparatus wherein a photosensitive member is scanned with a laser beam corresponding to the information signal of an image to be recorded, the power of the laser beam being controlled in accordance with the wavelength of the laser beam and the sensitivity of the photosensitive member.
    Type: Grant
    Filed: February 6, 1984
    Date of Patent: January 7, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaharu Ohkubo, Yoshihiro Murasawa, Yasumasa Ohtsuka, Jun Asai