Patents by Inventor Tomoaki Yokoyama

Tomoaki Yokoyama 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: 4828953
    Abstract: The present invention relates to a method for forming an outline of an image. By this method, at first, an electrostatic latent image bearing member is charged and then irradiated to a negative image to form an electrostatic latent image. Thereafter, the irradiated member is re-charged with a scorotron charger while applying a voltage to a grid, said voltage being lower than the surface potential of the non-image portion of the latent image, being higher than the potential of the image portion of the latent image and being of the same porality as that of the charging. By this re-charging, in one embodiment, the outline portion of the image has lower potential than the other portion. Then, the outline portion of the image with lower potential is visualized with a reversal development by using a toner charged to a polarity same as the polarity of charging.Or in another embodiment, the outline portion of the image has higher potential than the other portion.
    Type: Grant
    Filed: May 21, 1987
    Date of Patent: May 9, 1989
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama
  • Patent number: 4821071
    Abstract: An improved electrophotographic copier is proposed which includes a first static charger; an image exposure unit; a second charger provided with a grid; and a developer having a developing electrode, all being arranged around a photosensitive rotatable drum.The second charger is impressed selectively with an a.c. voltage or a d.c. voltage which has an opposite polarity to that applied to the first charger. The voltage impressed to the grid has same polarity with that which is applied to the first charger. The developing agent contained in the developer includes such statically charged toner as having an opposite polarity to that of static latent images formed on the drum surface. The copier operates selectively in standard copy mode or in marginal image outline formation mode. The developing service is nevertheless carried out in the normal manner, thus employing no reverse development mode.
    Type: Grant
    Filed: May 7, 1987
    Date of Patent: April 11, 1989
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Hisashi Myochin, Tomoaki Yokoyama
  • Patent number: 4794062
    Abstract: A method for forming an outline of an image. In this method, at first, an electrostatic latent image bearing member is charged and then irradiated to a positive image to form an electrostatic latent image. Thereafter, the irradiated member is re-charged with a scorotron charger while applying a voltage to a grid, the voltage being lower than the surface potential of the image portion of the latent image, being slightly higher than the background potential of the latent image and being of the same polarity as that of the original charging. By this re-charging, the outline portion of the image is given higher potential than the other portion. Then, the outline portion of the image with higher potential is subjected to a normal development by using a toner charged to a polarity opposite to the polarity of the recharged portions.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: December 27, 1988
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama
  • Patent number: 4792775
    Abstract: A method for forming an outline of an image. By this method, at first, an electrostatic latent image bearing member is charged and then irradiated to form an electrostatic latent image. Thereafter, the irradiated member is re-charged with a scorotron charger while applying a voltage to the scorotron grid, the voltage being slightly lower than the surface potential of the image portion of the latent image, and being substantially higher than the background potential of the latent image and being of the same polarity as that of the charging. By this re-charging, the outline portion of the image is given lower potential than the other portion. Then, the outline portion of the image with the lower potential is developed by a reversal development by using a toner charged to a polarity the same as the polarity of charging of the latent image bearing member.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: December 20, 1988
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama
  • Patent number: 4785331
    Abstract: An electrophotographic copying apparatus is capable of forming outline images. It comprises a first charging device, an exposing device, a second charging device and a developing device along a moving direction of a photoconductor. A sensor detects an amount of toner adhering to a reference image formed on the surface of the photoconductor. Supply of toner is controlled based on the detected amount. In an outline image forming mode, an amount of toner to be supplied is set to a value smaller than an amount in a standard image forming mode.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: November 15, 1988
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama
  • Patent number: 4766458
    Abstract: A developing apparatus which includes a developing sleeve rotatably provided to confront an object to be developed, a magnet roller incorporated within the developing sleeve so as to be driven for rotation in the same direction as the developing sleeve, and a supply device for supplying developing material onto the peripheral surface of the developing sleeve. The developing apparatus is so arranged as to satisfy such conditions asD.multidot..pi..multidot.Wsl>d1.multidot.p.multidot.WmgwhereD: developing sleeve diameter (mm)Wsl: developing sleeve revolutions (rpm)d1: the closest distance between the sleeve surface and the object to be developedp: number of poles of the magnet rollerWmg: revolutions of the magnet roller (rpm).
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: August 23, 1988
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Tomoaki Yokoyama, Naoki Toyoshi
  • Patent number: 4745437
    Abstract: The copier machine of the present invention comprises a second charger having a grid and is capable of executing a mode wherein a toner is deposited onto the latent image exclusive of the outline portion thereof to visualize.When this mode is designated, the grid is applied with the voltage which is lower than the surface potential at the image portion of the latent image and higher than the surface potential at the non-image portion of the latent image.
    Type: Grant
    Filed: July 8, 1987
    Date of Patent: May 17, 1988
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Tateki Oka, Naoki Toyoshi, Tomoaki Yokoyama