Patents by Inventor Kazunori Hirota

Kazunori Hirota 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).

  • Magnet roller, process for producing same and developing unit using same
    Patent number: 6324372
    Abstract: There are disclosed a magnet roller which includes a magnet main body portion and a shaft portion, wherein the magnet main body portion includes a composition for magnets and has at least one hollow portion in the inside thereof; a process for producing a magnet roller having a magnet main body portion and a shaft portion, which includes arranging in advance, at least one member for forming a hollow portion in a cavity of a mold which has generated a magnetic field on the circumference of the cavity, pouring a composition for magnets into the mold, and thereafter withdrawing the member for forming the hollow portion so that at least one hollow portion is formed in the inside of the magnet roller; and a developing unit which includes a developing roller constituted of a sleeve installed in a freely rotatable manner and the above magnet roller installed inside the sleeve.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: November 27, 2001
    Assignee: Bridgestone Corporation
    Inventor: Kazunori Hirota