Electronic watch
AssigneeKabushiki Kaisha Daini Seikosha
InventorsMasaharu Shida, Akira Torisawa, Jun Ueda, Masaaki Mandai, Katsuhiko Sato
Life of this patent
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Abstract
In an analog electronic watch having a calendar display the power required during change of the calendar display, about 6 hours out of 24, is greater than at other times. In order to effect economy in power consumption, the pulse for driving the watch motor during the time other than the period in which the calendar display is being changed is only sufficient to drive the time indicating means. In case the motor fails to step when such pulse is applied, this is detected by a detecting circuit and a corrective drive pulse is applied to the motor so as to drive it.
Claims14
In an analog electronic timepiece of the type having a stepping motor comprised of a stator, a drive coil wound on the stator, and a rotor rotationally driven in response to pulses applied to the drive coil:
- an oscillator circuit for generating high frequency signals suitable as a time standard;
- a frequency dividing circuit receptive of the high frequency signals for frequency-dividing the same into lower frequency time signals;
- a pulse combining circuit receptive of the lower frequency time signals for combining the same to produce normal drive pulses and correcting drive pulses having a greater effective power than the normal drive pulses for applying the same to the motor drive coil for driving said stepping motor;
- detecting circuit means operative after each normal drive pulse is applied to the motor drive coil and at a time non-coincident with the application of each normal drive pulse for detecting a non-rotated condition of the motor rotor;
- and means controlled by said detecting circuit means for applying a correcting drive pulse to the motor drive coil before the next normal drive pulse is applied thereto in response to detection of a non-rotated condition of the motor rotor by said detecting circuit means.
In a battery-powered analog electronic timepiece of the type having a stepping motor comprised of a stator, a drive coil wound on the stator, and a rotor rotationally driven in stepwise manner in response to pulses applied to the drive coil:
- an oscillator circuit for generating high frequency signals suitable as a time standard;
- a frequency dividing circuit receptive of the high frequency signals for frequency-dividing the same into lower frequency time signals;
- a pulse combining circuit receptive of the lower frequency time signals for developing therefrom a succession of normal drive pulses having a given pulse period and a given effective power effective to develop the torque needed to rotationally drive the motor rotor when the normal drive pulses are applied to the motor drive coil under relatively low load timepiece operating conditions and a succession of correcting drive pulses separate from the normal drive pulses and having the same given pulse period though a greater effective power than the normal drive pulses and effective to develop the higher torque needed to rotationally drive the motor rotor when the correcting drive pulses are applied to the motor drive coil under higher load timepiece operating conditions in which the normal drive pulses are ineffective to rotationally drive the motor rotor;
- and motor control circuit means coacting with said pulse combining circuit for applying drive pulses to the motor drive coil in such manner to reduce overall battery power consumption by applying successive normal drive pulses to the motor drive coil whenever the immediately preceding normal drive pulse effected stepwise advancement of the motor rotor and otherwise applying, within the same pulse period as the normal drive pulse which failed to effect stepwise advancement, a correcting drive pulse to the motor drive coil before applying thereto another normal drive pulse to effect stepwise advancement of the motor rotor thereby conserving battery power by using the normal drive pulses of lesser effective power whenever possible to drive the motor rotor and using the correcting drive pulses of greater effective power only when the normal drive pulses are ineffective to drive the motor rotor.
A battery-powered analog electronic timepiece according to claim 18;
- wherein said motor control circuit means includes detecting circuit means for detecting, after application of each normal drive pulse to the motor drive coil, whenever a normal drive pulse fails to effect stepwise advancement of the motor rotor, and means responsive to such detection for applying a correcting drive pulse to the motor drive coil before the next normal drive pulse is applied thereto.
A battery-powered analog electronic timepiece according to claim 12;
- wherein said pulse combining circuit includes means for developing normal drive pulses and correcting drive pulses of constant pulse width under all timepiece operating conditions.
Dependencies are inferred from the claim text.