Driving device and electronic timepiece

Patent metadata

Field	Value
Publication number	US-10520898-B2
Application number	US-201715460651-A
Country	US
Kind code	B2
Filing date	Mar 16, 2017
Priority date	Mar 22, 2016
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

A driving processor for driving a motor having a rotor and one or more coils for rotating the rotor is configured to generate a detection pulse for detecting whether or not the rotor has rotated; cause the generated detection pulse to be applied to at least one of the one or more coils; receive a signal indicating a detected value of current flowing in the at least one of the one or more coils after the detection pulse has been outputted to the at least one of the one or more coils; and determine whether or not the rotor has rotated to one or more prescribed positions on the basis of the detected value of current.

First claim

What is claimed is:

1. An electronic timepiece, comprising:
a motor having a rotor and at least two coils, the rotor being configured to rotate to a plurality of prescribed positions; and
a driving processor for driving the motor, the driving processor being configured to:
generate a detection pulse for detecting whether or not the rotor has rotated;
cause the generated detection pulse to be applied to at least one of said at least two coils;
receive a signal indicating a detected value of current flowing in the at least one of said at least two coils after the detection pulse has been outputted to the at least one of said at least two coils; and
determine whether or not the rotor has rotated to one of the plurality of prescribed positions on the basis of the detected value of current; and

a display unit including a hand driven by the rotor,
wherein, for each of the plurality of prescribed positions, the driving processor causes the detection pulse to be applied to one of the at least two coils that generates the greatest magnetic flux density, among the at least two coils, when the rotor has properly rotated to the prescribed position such that the detection pulse is applied to the at least two coils sequentially while the rotor is rotating normally, and
wherein the driving processor or another processor calculates a time and causes the hand to be driven to a position corresponding to the calculated time so as to display the time in the display unit.

2. The electronic timepiece according to claim 1 , wherein the processor:
causes the detection pulse to be applied to the at least one of said at least two coils for a prescribed period; and
receives the signal that indicates the detected value of current flowing in the at least one of said at least two coils after the prescribed period has ended.

3. The electronic timepiece according to claim 1 ,
wherein the detection pulse has a waveform in which a high-level period is 0.01 milliseconds to 1 millisecond.

4. The electronic timepiece according to claim 2 ,
wherein the detection pulse has a waveform in which a high-level period is 0.01 milliseconds to 1 millisecond.

Assignees

• Casio Computer Co Ltd

Inventors

• Saito Yuta

Classifications

• H02P8/02

  specially adapted for single-phase or bi-pole stepper motors, e.g. watch-motors, clock-motors · CPC title

• H02P8/38

  the fault being step-out · CPC title

• G04C3/143 Primary

  Means to reduce power consumption by reducing pulse width or amplitude and related problems, e.g. detection of unwanted or missing step · CPC title

• H02P8/22 Primary

  Control of step size; Intermediate stepping, e.g. microstepping · CPC title

• H02P8/34

  Monitoring operation (H02P8/36 takes precedence) · CPC title