Patents by Inventor Yasuo Mitsuhashi

Yasuo Mitsuhashi 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: 4957840
    Abstract: A developer for developing electrostatic images, comprising a magnetic toner comprising a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:N/V=-0.04N+k,wherein N denotes % by number of magnetic toner particles of 5 micron or smaller, V denotes % by volume of magnetic toner particles of 5 microns or smaller, k denotes a positive number of 4.5-6.5, and N denotes a positive number of 17-60.
    Type: Grant
    Filed: October 25, 1988
    Date of Patent: September 18, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kiichiro Sakashita, Toshiaki Nakahara, Hirohide Tanikawa, Naoki Matsushige, Satoshi Yoshida, Masatsugu Fujiwara, Yasuo Mitsuhashi
  • Patent number: 4949173
    Abstract: The intermittent magnetic recording/reproducing device of the present invention intermittently drives a rotating drum (10) by an intermittent driving circuit (6) and surface-records a frequency-modulated video signal on a magnetic tape intermittently by video heads (11, 12). On the other hand, an audio signal is converted into a digital signal by an AD converter (22), whose bit number is decreased by a 6-4 converter (23) and a correction code is added thereto by a correction code generation circuit (24). The time base of the digital audio signal is compressed by a time base compression modulation circuit (25) and the signal is deep-recorded on the magnetic tape by audio heads (13, 14) provided on the rotating drum (10). Audio heads (13, 14) have a wider gap width than the video heads (11, 12) and the azimuth angle thereof is different from that of the video heads. Therefore, even if the video signal and the digital audio signal are recorded on the same track, there is no interference between each other.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: August 14, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yasuo Mitsuhashi
  • Patent number: 4737432
    Abstract: A positively chargeable toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The toner contains a binder resin, a colorant or magnetic material, and a diorganotin borate. Because of the diorganotin borate contained, the toner has a uniform and stable triboelectric chargeability. The improved properties of the toner are enhanced when it is combined with positively chargeable fine silica powder.
    Type: Grant
    Filed: September 15, 1986
    Date of Patent: April 12, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhiko Tanaka, Hirohide Tanikawa, Naoto Kitamori, Tsutomu Kukimoto, Masaki Uchiyama, Yasuo Mitsuhashi
  • Patent number: 4723180
    Abstract: A motor drive amount correction signal generating circuit (14) corrects a deviation of an intermittent feed amount of a magnetic tape (1) by using reverse rotation pulse groups (t.sub.1, t.sub.2, t.sub.3, etc.) or forward rotation pulse groups (t.sub.1 ', t.sub.2 ', t.sub.3 ', etc.) and if the deviation is beyond a permissible range, the level of the braking voltage generated from a motor drive circuit (7) is changed in the subsequent drive period in intermittent recording.
    Type: Grant
    Filed: February 19, 1986
    Date of Patent: February 2, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Takafumi Inadomi
  • Patent number: 4699865
    Abstract: A process for developing a latent image with a developer is provided which comprises(1) forming a layer of a developer comprising a magnetic toner containing magnetic powder having a BET specific surface area of 2 to 20 m.sup.2 /g on a member for supporting the developer,(2) bringing an electrophotographic photosensitive member holding the latent image into contact with said developer layer, said electrophotographic photosensitive member comprising an organic photoconductive material having a surface hardness more than 10 g,(3) forming a toner image on said electrophotographic photosensitive member,(4) transferring the toner image onto the transfer material, and(5) cleaning the electrophotographic photosensitive member having passed through the transferring step with a cleaning member. Said developer may alternatively comprises magnetic particles containing a binder and magnetic powder having a BET specific surface area of 2 to 20 m.sup.
    Type: Grant
    Filed: March 11, 1987
    Date of Patent: October 13, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasuo Mitsuhashi
  • Patent number: 4700255
    Abstract: When a standby command is issued in a long-period recording (intermittent recording) mode, a control circuit 70 stops the rotation of a rotating drum 60 and a capstan shaft 72 with a magnetic tape 20 being maintained in a loaded state. Then, a back tension arm 310 is moved and rotating torques are applied to a feed reel 11 and a take-up reel 12 in opposite directions, whereby a prescribed back tension is applied to the magnetic tape 20.
    Type: Grant
    Filed: February 27, 1986
    Date of Patent: October 13, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yasuo Mitsuhashi
  • Patent number: 4640882
    Abstract: A negative latent image is formed on a photosensitive member comprising an organic photoconductive material. The negative latent image is developed with a positively chargeable developer containing positively chargeable fine silica particles adapted to the organic photosensitive member. The developed image is transferred to a transfer material and the residual toner on the photosensitive member is removed. Thus, copied images without fog can be obtained successively.
    Type: Grant
    Filed: July 9, 1984
    Date of Patent: February 3, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masaki Uchiyama, Kazunori Murakawa, Kenji Okado
  • Patent number: 4626487
    Abstract: A developer comprising colored resinous particles and inorganic fine particles having a BET specific surface area of 0.2 to 30 m.sup.2 /g as measured by nitrogen adsorption. The inorganic fine particles have an action of promoting removal of paper powder and other adherents during cleaning of the latent image-bearing member without sticking onto the latent image-bearing member. Accordingly, the developer containing the inorganic fine particles can give good images even after successive copying operation for a long term.
    Type: Grant
    Filed: July 25, 1984
    Date of Patent: December 2, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masaki Uchiyama, Kazunori Murakawa, Kenji Okado
  • Patent number: 4622281
    Abstract: A magnetic color toner stable to heat and light which does not fade or discolor for a long period of time is prepared by incorporating .gamma.-Fe.sub.2 O.sub.3 particles as a magnetic component in a toner.
    Type: Grant
    Filed: January 3, 1986
    Date of Patent: November 11, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eiichi Imai, Hiroyuki Kobayashi, Yasuo Mitsuhashi
  • Patent number: 4592987
    Abstract: A method for applying a toner comprising: forming, in a container containing a toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; and forming a thin layer of the toner electrically charged on the toner carrying member; wherein the magnetic particles have a particle size distribution of 30 wt. % or more in the range of 150 to 200 mesh and 5 wt. % or less of under 250 mesh, and the weight ratio of the toner to the magnetic particles is from 5:95 to 50:50 in the region where the magnetic brush is formed.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: June 3, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masanori Takenouchi, Kenji Okado, Eiichi Imai, Koshi Suematsu
  • Patent number: 4590140
    Abstract: A method for applying a toner comprising: forming, in a container containing a toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; forming a thin layer of the toner electrically charged on the toner carrying member, wherein the magnetic particles have been treated with a substance A having a position opposite to that of the toner in the triboelectric series with the material constituting at least the surface of the toner carrying member as the standard substance and with a substance B having a position between the substance A and the toner in the triboelectric series.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: May 20, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masanori Takenouchi, Hatsuo Tajima, Masaki Uchiyama, Motoo Urawa, Kenji Okado
  • Patent number: 4568625
    Abstract: A developer contains a silicone oil which has an amine on side chain thereof, a development process comprises arranging a member holding an electrostatic image on the surface and a member for carrying a toner on the surface and a fixing method comprises contacting a toner image on an image-supporting member with a heated roller, said toner image being formed of a toner which contains a silicone oil having an amine on side chain thereof and has an MI of 0.01-10 g/10 min.
    Type: Grant
    Filed: April 24, 1984
    Date of Patent: February 4, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Uchiyama, Yasuo Mitsuhashi, Kazunori Murakawa, Masanori Takenouchi, Eiichi Imai, Koushi Suematsu
  • Patent number: 4565766
    Abstract: A developing powder comprises a binder containing 50% by weight or more of a polymer having a gel content of 10% or less and prepared from a vinyl type monomer and a crosslinking agent monomer contained in an amount of 0.01-10% by weight based on the total weight of the monomers, and 0.1-5% by weight of an olefin homopolymer or copolymer having a melt viscosity at 140.degree. C. of 10-10.sup.6 cps.
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: January 21, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masaki Uchiyama
  • Patent number: 4565763
    Abstract: A process for producing a toner includes melt-blending at least a colorant and a polymer and finely pulverizing the resulting blend after cooling, wherein the polymer is a crosslinked resin having a ratio of weight-average molecular weight to number-average molecular weight (Mw/Mn) exceeding 4.0 and a melt index of 0.01-10 g/10 min. at 110.degree. C. under a load of 10 Kg and the polymer is further crosslinked to form gel during the melt-blending. The toner thus obtained exhibits a good fixability without offset phenomenon over a wide temperature range.
    Type: Grant
    Filed: May 26, 1983
    Date of Patent: January 21, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Uchiyama, Yasuo Mitsuhashi
  • Patent number: 4543312
    Abstract: A magnetic toner comprises magnetic powders having a particle distribution that the particle size of 50% accumulated volume, the particle size of 25% accumulated volume and the particle size of 75% accumulated volume of the magnetic powders are 1.5-4.5.mu., 1.0-4.0.mu. and 2.5-6.0.mu., respectively. This magnetic toner can produce high density and clear images and further, can produce colorful images.
    Type: Grant
    Filed: April 26, 1983
    Date of Patent: September 24, 1985
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunori Murakawa, Yasuo Mitsuhashi, Hitoshi Uchide, Seiichi Takagi, Masaki Uchiyama, Hisayuki Ochi, Motoo Urawa, Eiichi Imai
  • Patent number: 4522907
    Abstract: A method for developing electric latent images with a triboelectrified toner without use of carrier particles therefor comprises using as a member for imparting triboelectric charges to said toner, a member containing at least on the surface at least one kind selected from poly (phenylene oxide); polycarbonate, styrene type resin, silicone resin, polymer of vinyl ester type monomer, silane compound, and polyethersulfone. Also, an apparatus for developing electric latent images comprises a toner-holding member, a means for supplying a toner to said toner-holding member and a means for moving said toner-holding member and supplying said toner to a portion for development of the electric latent images; in which at least the surface of said toner-holding member contains at least one kind selected from poly (phenylene oxide), polycarbonate, styrene type resin, silicone resin, polymer of vinyl ester type monomer, silane compound, and polyethersulfone.
    Type: Grant
    Filed: September 2, 1983
    Date of Patent: June 11, 1985
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Ichiro Ohsaki
  • Patent number: 4499168
    Abstract: Fixing method, in which developing powder containing therein vinyl type polymers having at least one molecular peak thereof in the molecular weight regions of 10.sup.3 to 8.times.10.sup.4 and 10.sup.5 to 2.times.10.sup.6, respectively, in a chromatogram measured by the gel permeation chromatography (G.P.C.) is fixed by a fuser roller.
    Type: Grant
    Filed: April 27, 1984
    Date of Patent: February 12, 1985
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasuo Mitsuhashi
  • Patent number: 4481274
    Abstract: A developing powder comprises a binder containing 50% by weight or more of a polymer having a gel content of 10% or less and prepared from a vinyl type monomer and a crosslinking agent monomer contained in an amount of 0.01-10% by weight based on the total weight of the monomers, and 0.1-5% by weight of an olefin homopolymer or copolymer having a melt viscosity at 140.degree. C. of 10-10.sup.6 cps.
    Type: Grant
    Filed: November 6, 1981
    Date of Patent: November 6, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuo Mitsuhashi, Masaki Uchiyama
  • Patent number: 4448870
    Abstract: Red to sepia magnetic toners stable to heat and light which do not fade or discolor for a long period of time are prepared by incorporating a partially .alpha.-transformed .gamma.-Fe.sub.2 O.sub.3 as a component in a toner.
    Type: Grant
    Filed: April 11, 1983
    Date of Patent: May 15, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eiichi Imai, Hitoshi Uchide, Kazunori Murakawa, Masaki Uchiyama, Hisayuki Ochi, Motoo Urawa, Seiichi Takagi, Yasuo Mitsuhashi
  • Patent number: 4430411
    Abstract: A developing device in which a one-component magnetic developer is brought into contact with an electrostatic image carrier in a developing station while it is conveyed in a predetermined direction, to thereby develop a desired electrostatic image is provided with developer carrier means carrying the one-component magnetic developer on the peripheral surface thereof and bringing the developer into contact with the electrostatic image carrier, means for moving a magnetic field along the peripheral surface of the developer carrier means to thereby move the one-component magnetic developer in the direction opposite to the direction of movement of the magnetic field, and means for moving the developer carrier means in the direction of movement of the magnetic field.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: February 7, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasuyuki Tamura, Masashi Kiuchi, Tohru Takahashi, Yasuo Mitsuhashi, Seiji Tomari