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:
Apr. 15, 2003
Filed:
Sep. 13, 1999
Applicant:
Inventors:
James E. Colley, Junction City, OR (US);
Edward P. Coleman, Liverpool, NY (US);
Assignee:
PSC Scanning, Inc., Eugene, OR (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 5/08 ;
U.S. Cl.
CPC ...
G02B 5/08 ;
Abstract
A method for driving a resonant electromagnetically-actuated motor, such as those used to scan a light source for date reading applications, wherein drive current is applied when the back-EMF induced in the actuator coil is zero and has a specific slope, and that drive current is removed after the induced back-EMF voltage has changed by a predetermined constant value. The drive circuit will drive the motor across a scan angle which remains substantially constant regardless of changes in ambient temperature, changes in motor orientation, or externally applied forces.