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:
Jul. 20, 1982
Filed:
Jul. 24, 1980
Applicant:
Inventors:
Fumio Kanno, Tokorozawa, JP;
Fumio Nakajima, Tokorozawa, JP;
Assignee:
Citizen Watch Company Limited, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G04B / ;
U.S. Cl.
CPC ...
368 76 ; 368157 ; 318696 ;
Abstract
An electronic timepiece havig a stepping motor driving time indicating hands is provided with a system whereby the stepping motor is selectively driven at one of three different drive power levels, in accordance with the load currently being applied to the motor. Detection of the load level is performed by momentarily sampling a voltage induced in the motor drive coil during a short time interval following a drive pulse. The system provides rapid response to changes in load level, highly stable control, and excellent tolerance to variations in characteristics of different stepping motors and circuit components.