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:
Mar. 23, 1982
Filed:
Dec. 04, 1979
Makoto Ueda, Tokyo, JP;
Akira Torisawa, Tokyo, JP;
Shuji Otawa, Tokyo, JP;
Masaaki Mandai, Tokyo, JP;
Masaharu Shida, Tokyo, JP;
Katsuhiko Sato, Tokyo, JP;
Kabushiki Kaisha Daini Seikosha, Tokyo, JP;
Abstract
An electronic timepiece has a stepping motor comprised of a stator, rotor and driving coil. A wave shaping circuit produces normal driving pulses and correction driving pulses having a longer pulse width than the normal driving pulses. A rotor rotation detection device detects rotation and non-rotation of the rotor after normal driving pulses are applied to the driving coil and in response to detection of a non-rotation condition, a correction driving pulse is applied to the driving coil. A magnetic field detection device detects the presence and absence of an external alternating magnetic field and in response to detection of a magnetic field, a driving pulse of longer pulse width than the correction driving pulses is applied to the driving coil to effect rotor rotation. The magnetic field detection device operates before the normal driving pulses are applied to the driving coil so that in the event of detection of a magnetic field, a driving pulse of sufficiently long pulse width will be applied to the driving coil to effect rotor rotation. In response to detection of an external alternating magnetic field by the magnetic field detection device, operation of the rotor rotation detection device is inhibited thereby conserving power and preventing mis-operation of the stepping motor.