Patents by Inventor Nobuaki Kato

Nobuaki Kato 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: 4879502
    Abstract: In speed control apparatus and method for a motor operable to drive a load whose magnitude varies over a predetermined period which use a unit for controlling voltage or current supplied to the motor such that the speed of the motor can coincide with a command speed, n pieces of data indicative of voltages or currents supplied to the motor and corresponding to n divisions of the predetermined period are independently stored in a read/write storage, at least one of the n pieces of data is corrected at the rate of each of the n divisions in accordance with a difference between the command speed and the speed of the motor, and the voltage or current supplied to the motor is controlled in accordance with at least the one of the n pieces of data, so that pulsation and noise occurring especially under low revolutions can be minimized.
    Type: Grant
    Filed: May 10, 1988
    Date of Patent: November 7, 1989
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Tunehiro Endo, Nobuaki Kato, Kenichi Iizuka, Fumio Tajima