Patents by Inventor Tatsuya Tada

Tatsuya Tada 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: 5517286
    Abstract: A stationary magnet is disposed in a developing sleeve for carrying a one component magnetic developer. A regulating sleeve for regulating a layer of the developer is disposed opposed to the developing sleeve. The regulating sleeve rotates in the same direction as the developing sleeve. In the regulating sleeve, there is disposed a magnet or magnetic member cooperative with the stationary magnet to form a magnetic field in a gap between the developing sleeve and the regulating sleeve.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: May 14, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tatsuya Tada, Isami Itoh
  • Patent number: 5512406
    Abstract: A toner for electrophotography, comprising toner particles and an additive, is obtained by mixing toners A and B together which are obtained by respectively adding the additive to each of at least two toner particle groups (a) and (b) having different particle size distributions. The average particle size of the toner particle group (a) is smaller than that of the toner particle group (b), and the amount of additive in the toner A is larger than that in the toner B. The toner reduces the differences in development conditions between different particle sizes due to broadening of toner particle size distribution, thereby enabling a stable image quality to be obtained which maintains a high image density for an extended period of time and is relatively free from fog generation in non-image portions.
    Type: Grant
    Filed: October 12, 1994
    Date of Patent: April 30, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenichi Takeda, Tatsuya Tada, Nobuyuki Itoh, Masao Nakano, Kazuhisa Kemmochi, Isami Itoh
  • Patent number: 5464720
    Abstract: An image forming method is disclosed which comprises forming a latent image on a latent image bearing member, carrying a magnetic toner onto a developer carrying member provided with a magnetic field forming means, forming on the developer carrying member a layer of the magnetic toner, and developing the latent image while transferring the magnetic toner to the latent image bearing member. The magnetic toner contains a magnetic material having an intensity of magnetization of from 10 emu/g to 40 emu/g in a magnetic field of 1K oersted and formed of a metal oxide having a horizontal direction Feret's diameter of from 0.05 .mu.m to 0.5 .mu.m, and chainlike masses of the magnetic toner, formed on the developer carrying member, are in a density of not less than 8.times.10.sup.4 ears/cm.sup.2 in a developing zone formed between the latent image bearing member and developer carrying member. The chainlike masses each have a length of not more than 180 .mu.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: November 7, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Baba, Tatsuya Tada
  • Patent number: 4985823
    Abstract: An image-forming apparatus for developing an electrostatic latent image using a two-component developer. Toner replenishment is effected in different modes when the toner concentration is in a lower toner concentration range than a desired toner concentration and when it is lower than that toner concentration range.
    Type: Grant
    Filed: August 31, 1989
    Date of Patent: January 15, 1991
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tatsuya Tada, Yasuyoshi Yamamoto
  • Patent number: 4942431
    Abstract: An image forming apparatus includes an image bearing member; a latent image forming device for forming a latent image on the image bearing member; a developing device for developing the latent image, including, a developer container for containing a developer including carrier and toner particles, a toner container for containing the toner particles, a toner supply device for supplying the toner particles from the toner container to the developer container, a developer carrying member for carrying on its surface the developer supplied from the developer container, a sensor for detecting a toner content in the developer; a control device for controlling the toner supply from the toner container to the developer container on the basis of an output of the sensor, wherein when a toner supply signal is not produced within a predetermined period of time, a predetermined latent image is formed on the image bearing member, and the predetermined latent image is developed by the developing device.
    Type: Grant
    Filed: August 25, 1989
    Date of Patent: July 17, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tatsuya Tada
  • Patent number: 4777512
    Abstract: An image forming apparatus using two component developer. When a toner content in the developer becomes out of a predetermined range as a result of the consumption of the toner, a control device effects a toner replenishing operation, and simultaneously, the image forming operation is substantially delayed.
    Type: Grant
    Filed: December 9, 1986
    Date of Patent: October 11, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masayoshi Takahashi, Nobutoshi Yoshida, Ikumi Omura, Tatsuya Tada