The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 02, 1997
Filed:
Mar. 05, 1992
Applicant:
Inventor:
Robert P Callaway, Vancouver, WA (US);
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318696 ; 318254 ;
Abstract
A closed-loop method and apparatus for controlling acceleration and velocity of a stepper motor in which a motor shaft encoder is used to generate a signal proportional to shaft position. This signal is subtracted from the motor input signal to produce an error signal which is compared with a reference value. When the error is equal to the reference value the motor is stepped again. Between each step, the reference value is decreased if motor velocity is too high or increased if the motor velocity is too low.