Patents by Inventor Shigemoto Tazawa

Shigemoto Tazawa 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).

  • System for controlling drive of a wafer stage
    Patent number: 4641071
    Abstract: A system for controlling drive of a movable member for carrying a workpiece such as a semiconductor wafer, the system including a first servo control system effective to move the workpiece carrying member at a relatively high speed and with a relatively low positional accuracy for stoppage of the workpiece carrying member, a second servo control system effective to move the workpiece carrying member at a relatively low speed and with a relatively high positional accuracy for the stoppage of the workpiece carrying member, and a system for selecting one of or a combination of the first and second servo control system in accordance with a positional accuracy required with respect to a target position of the workpiece carrying member.
    Type: Grant
    Filed: September 25, 1985
    Date of Patent: February 3, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigemoto Tazawa, Naoki Ayata