Patents by Inventor Frederick Helm

Frederick Helm 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).

  • Laser scanner using two scan motors independently controlled by a single signal
    Patent number: 5266787
    Abstract: A dual motor speed control circuit for providing independent speed control of two motors in a laser scanning device is disclosed herein. This apparatus utilizes a single input signal having variable frequency and duty cycle components. The speed of the first motor is controlled by utilizing the frequency component of said input signal while the speed of the second motor is controlled by utilizing the frequency and duty cycle components of said input signal. Specifically, a DC signal is generated that is dependent upon the duty cycle component of said input signal and said DC signal is utilized to offset the speed of the second motor from the speed value as determined by the frequency component of said input signal.
    Type: Grant
    Filed: January 11, 1991
    Date of Patent: November 30, 1993
    Assignee: Symbol Technologies, Inc.
    Inventors: Thomas Mazz, Anthony Fama, Frederick Helm