Step motor drive unit and analog electronic timepiece
AssigneeSeiko Instruments Inc.
InventorKenji Ogasawara
Life of this patent
Estimating the term…
Abstract
To make it possible by a simple constitution to perform a forcible rotation drive by a correction drive pulse and obtain a demagnetization effect. In a case where a control circuit has judged on the basis of a detection signal from a rotation detection circuit 106 that a motor has not rotated by a drive by a 1st normal drive pulse of a predetermined energy, after it has forcibly rotation-driven the motor by a correction drive pulse whose energy is larger than the 1st normal drive pulse, it rotation-drives the motor by a 2nd normal drive pulse whose polarity differs from the correction drive pulse and whose energy is larger than the 1st normal drive pulse.
Claims8
A step motor drive unit comprising:
- a step motor having a stator, a coil wound in the stator and a rotor rotatably held in the stator;
- and
- a drive circuit for supp1lying a drive pulse whose polarity alternately differs to the coil and which generates a magnetic flux whose polarity alternately differs in the stator by supplying the drive pulse to the coil from the drive circuit, thereby rotation-driving the rotor in the same direction by a predetermined angle at a time by each of the magnetic flux whose polarity differs;
- and
- a control means which, after detecting the fact that the rotor was not rotated by a 1st normal drive pulse of a predetermined energy and rotation-driving the rotor by a correction drive pulse whose energy is larger than the 1st normal drive pulse, rotation-drives the rotor by a 2nd normal drive pulse whose polarity differs from the correction drive pulse and whose energy is larger than the 1st normal drive pulse and smaller than the correction drive pulse.
Dependencies are inferred from the claim text.