Control device for stepper motor, control method for the same, and timing device

• US 6,339,306 B1
• Filed: 06/27/2000
• Issued: 01/15/2002
• Est. Priority Date: 02/07/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hara, Tatsuo
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/604,623
• Time in Patent Office: 567 Days
• Field of Search: 318/560-696, 368/64, 368/66, 368/151, 368/204, 368/205
• US Class Current: 318/696
• CPC Class Codes: G04C 3/143 Means to reduce power consumption by reducing pulse width or amplitude and related problems, e.g. detection of unwanted or missing step

Abstract

A control device for stepping motor including a driving pulse supplying unit for supplying a plurality of driving pulses to a driving coil for driving a rotor. A rotation detecting pulse supplying unit supplies rotation detection pulses for detecting whether the rotor rotated. A magnetic field pulse supplying unit supplies a plurality of magnetic field detection pulses for detecting the presence of magnetic field external to said stepping motor. A detection unit determines whether the driving rotor rotated and whether a magnetic field is present. An auxiliary pulse supplying unit supplies an auxiliary pulse when either rotor was not detected or when said an external magnetic field was detected. Before the driving pulse, is output, two said magnetic field detecting means magnetic field detecting pulses having different polarities are output.

Claims

1. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

magnetic field detecting means for supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse; and

wherein, prior to output of said driving pulse, said magnetic field detecting means supplies to said driving coil a first magnetic field detecting pulse having a first polarity and a second magnetic field detecting pulse having a second polarity for detecting magnetic fields of approximately the same frequency band.

2. The timepiece of claim 1, said control device further comprising a rotation detecting means for supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse.

3. The timepiece of claim 2, said control device further comprising an evaluating means for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present.

4. The timepiece of claim 3, said control device further comprising an auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

5. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and a an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

rotation detecting means for supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse;

magnetic field detecting means for supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse; and

wherein said magnetic field detecting means supplies a first magnetic field detecting pulse to said driving coil prior to output of said driving pulse and a second magnetic field detecting pulse to said driving coil after output of said rotation detecting pulse.

6. The timepiece of claim 5, said control device further comprising an evaluating means for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present.

7. The timepiece of claim 6, said control device further comprising an auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

8. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for storing a voltage charge and supplying an electric power to the driving rotor, said control device comprising:

magnetic field detecting means for supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse;

evaluating means for comparing the magnetic field detecting induction voltage with a second set value for determining whether said magnetic field is present; and

wherein said evaluating means adjusts said second set value used for evaluating said magnetic field detecting induction voltage based on said voltage charge stored in said condenser means.

9. The timepiece of claim 8, said control device further comprising a driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power.

10. The timepiece of claim 9, said control device further comprising a rotation detecting means for supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse.

11. The timepiece of claim 10, said control device further comprising an auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output or said driving pulse, is not detected or when said external magnetic field has been detected.

12. The timepiece of claim 8, said control device further comprising an auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

13. A timepiece comprising a control device for a stepping motor, the stepping motor being driven by driving pulses via a driving coil, an electricity generating device for generating electric power, and causing a magnetic field during said generating of said electric power, said electric power to the control device, said control device comprising:

driving means for supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power; and

auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, and;

said auxiliary means providing said auxiliary pulse when said electricity generating device is generating the electric power.

14. A timepiece of claim 13, wherein said electricity generating device is driven by a kinetic energy transferring means.

15. A timepiece of claim 13, further comprising an energy storing device for receiving the electric power.

16. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near all electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

short-pulse supplying means for supplying a plurality of short-pulse pulses having a shorter cycle than said driving pulses to said driving coil;

wherein said short-pulse supplying means stops supplying said short-pulse when said generating device is generating electricity.

17. The timepiece of claim 16, said control device further comprising a driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power.

18. The timepiece of claim 17, wherein said plurality of short-pulse pulses includes at least one of either a fast-forward pulse or a reverse pulse.

19. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

rotation detecting means for supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse;

magnetic field detecting means for supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse;

evaluating means for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present;

auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected; and

wherein said driving means supplies said driving pulses having a plurality of effective electric powers, and at least one of said driving pulses has a greater effective electric power than the effective electric power of an immediately preceding one of said driving pulses, said at least one of said driving pulses being supplied after said auxiliary pulse is supplied.

20. The timepiece of claim 19, wherein said driving pulses have one of a plurality of pulse widths.

21. The timepiece of claim 19, wherein said driving pulses have one or a plurality of voltages.

22. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring, means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

driving means for supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

rotation detecting means for supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse;

magnetic field detecting means for supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse;

evaluating means for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present;

auxiliary means for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulses, said auxiliary pulse being output when rotation of said driving rotor, in response to outlet of said driving pulse, is not detected or when said external magnetic field has been detected, said auxiliary pulse having a polarity; and

demagnetizing means for providing a demagnetizing pulse having a polarity that is different than said polarity of said auxiliary pulse, said demagnetizing pulse being output after said auxiliary pulse for demagnetizing said driving coil; and

wherein a following driving pulse is output following said auxiliary pulse, and said demagnetizing pulse is output immediately prior to said following driving pulse.

23. A control method for a timepiece having a stepper motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control method comprising the steps of:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulse having an effective electric power;

outputting a rotation detection pulse to said driving coil following output of said driving pulse for obtaining a rotation detection induction voltage;

comparing said rotation detection induction voltage with a first set value;

determining whether said driving rotor rotated;

outputting a plurality of magnetic field detection pulses having a plurality of polarities to said driving coil for obtaining a plurality of magnetic field detection induction voltages, said magnetic field detection pulses being output prior to said driving pulse;

comparing said plurality of magnetic field detection induction voltages individually with a second set value for detecting the presence of magnetic fields of approximately the same frequency band; and

supplying an auxiliary pulse having an effective electric power that is greater than said effective power of said driving pulse, said auxiliary pulse being supplied when rotation of said driving rotor in response to output of said driving pulse is not detected or when said external magnetic field has been detected.

24. A control method for a timepiece having a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control method comprising the steps:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulse having an effective electric power;

outputting a rotation detection pulse to said driving coil following output of said driving pulse for obtaining a rotation detection induction voltage;

comparing said rotation detection induction voltage with a first set value;

determining whether said driving rotor rotated;

outputting a first magnetic field detection pulse to said driving coil for obtaining a first magnetic field detection induction voltage, said first magnetic field detection pulse being output prior to said driving pulse;

comparing said first magnetic field detection induction voltage with a second set value for detecting the presence of a magnetic field;

outputting a second magnetic field detection pulse to said driving coil for obtaining a second magnetic field detection induction voltage, said second magnetic field detection pulse being output following said rotation detecting pulse;

comparing said second magnetic field induction voltage with said second set value for detecting the presence of said magnetic field; and

supplying an auxiliary pulse leaving an effective electric power that is greater than said effective power of said driving pulse, said auxiliary pulse being supplied when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

25. A control method for a timepiece having a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control method comprising the steps:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulse having an effective electric power;

outputting a rotation detection pulse to said driving coil following output of said driving pulse for obtaining a rotation detection induction voltage;

comparing said rotation detection induction voltage with a first set value;

determining whether said driving rotor rotated;

outputting a magnetic field detection pulse to said driving coil for obtaining a magnetic field detection induction voltage, said magnetic field detection pulse being output prior to said driving pulse;

adjusting a second set value according to a voltage charge of said energy storing device;

comparing said magnetic field detection induction voltage with said second set value for detecting the presence of a magnetic field; and

supplying an auxiliary pulse having an effective electric power that is greater than said effective power of said driving pulse, said auxiliary pulse being supplied when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

26. A control method for a timepiece having a stepping motor, the stepping motor including a driving coil, an electricity generating device for generating electric power and causing a magnetic field during said generating of electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating coil for generating electric power and applying said electrical power to the control device, said control method comprising the steps of:

supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulse having an effective electric power; and

supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being supplied when said electric generating device is generating electric power.

27. The control method for a timepiece of claim 26, wherein said electricity generating device is driven by a kinetic energy transferring unit.

28. The control method for a timepiece of claim 26, wherein the timepiece has an energy storing device for receiving the electric power.

29. A control method for a timepiece having a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control method comprising the steps of:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having a cycle;

supplying to said driving coil a plurality of short-pulse pulses having a cycle that is shorter than said cycle of said driving pulses; and

terminating output of said plurality of short-pulse pulses when said generating device is generating electricity.

30. The control method for a timepiece of claim 29, wherein said plurality of short-pulse pulses includes at least one of either a fast-forward pulse or a reverse pulse.

31. A control method for a time piece having a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control method comprising the steps of:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulse having an effective electric power;

outputting a rotation detection pulse to said driving coil following output of said driving pulse for obtaining a rotation detection induction voltage;

comparing said rotation detection induction voltage with a first set value;

determining whether said driving rotor rotated;

outputting a magnetic field detection pulse to said driving coil for obtaining a magnetic field detection induction voltage, said magnetic field detection pulse being output prior to said driving pulse;

comparing said magnetic field detection induction voltage with a second set value for detecting the presence of a magnetic field;

supplying an auxiliary pulse having an effective electric power that is greater than said effective power of said driving pulse, said auxiliary pulse being supplied when rotation of said driving rotor in response to output of said driving pulse is not detected or when said external magnetic field has been detected; and

supplying at least one of said driving pulses having a greater effective electric power than the effective electric power of an immediately preceding one of said driving pulse, said at least one of said driving pulses being supplied after said auxiliary pulse being supplied.

32. The control method for a timepiece of claim 31, wherein supplying at least one of said driving pulses step includes supplying said at least one of said driving pulses having different pulse widths.

33. The control method for a timepiece of claim 31, wherein supplying at least one of said driving pulses step includes supplying said at least one of said driving pulses driving pulses having different pulse voltages.

34. A control method for a timepiece having a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by kinetic energy transferring means, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said method device comprising the steps of:

supplying a plurality of driving pulses to said driving coil for driving said driving rotor;

outputting a rotation detection pulse to said driving coil following output of said driving pulse for obtaining a rotation detection induction voltage;

comparing said rotation detection induction voltage with a first set value;

determining whether said driving rotor rotated;

outputting a magnetic field detection pulse to said driving coil for obtaining a magnetic field detection induction voltage, said magnetic field detection pulse being output prior to said driving pulse;

comparing said magnetic field detection induction voltage with a second set value for detecting the presence of a magnetic field;

supplying an auxiliary pulse having an effective electric power that is greater than said effective power of said driving pulse, said auxiliary pulse being supplied when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected, said auxiliary pulse having a polarity;

providing a demagnetizing pulse having a polarity that is different than said polarity of said auxiliary pulse, said demagnetizing pulse being output after said auxiliary pulse for demagnetizing said driving coil; and

supplying a following driving pulse immediately after said demagnetizing pulse, said following driving pulse being output following said auxiliary pulse.

35. A timepiece comprising a control device, said control device having a stepping motor, the stepping motor including a driving coil, said stepping motor being driven by driving pulses via said driving coil, an electricity generating device for generating electric power, and causing a magnetic field during said generating of said electric power, said electricity generating device being driven by a kinetic energy transferring unit, and an energy storing device for receiving the electric power and applying said electric power to die control device, said control device comprising:

a drive pulse supply unit coupled to said driving coil and supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power;

a magnetic field pulse supplying unit coupled to said driving coil and supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, a magnetic field detection pulse being supplied prior to said driving pulse; and

wherein, prior to output of said driving pulse, said magnetic field pulse supplying unit supplies to said driving coil a first magnetic field detecting pulse having a first polarity and a second magnetic field detecting pulse having a second polarity for detecting magnetic fields of approximately the same frequency band.

36. The timepiece of claim 35 further comprising a rotation detecting pulse supplying unit coupled to said driving coil and supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said stepping motor, said rotation detection pulse being supplied following said driving pulse.

37. The timepiece of claim 36 further comprising a detecting circuit coupled to said driving coil for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said stepping motor rotated and whether said magnetic field is present.

38. The timepiece of claim 37 further comprising an auxiliary pulse supplying unit connected to said driving coil for supplying an auxiliary pulse having at effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said stepping motor in response to output of said driving pulse is not detected or when said external magnetic field has been detected.

39. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving coil, said stepping motor being driven by driving pulses via said driving coil, an electricity generating device for generating electric power and causing a magnetic field during said generating of electric power, said electricity generating device being driven by a kinetic energy transferring unit, and an energy storing device for receiving the electric power and applying said electric power to the control device, said control device comprising:

a drive pulse supply unit coupled to said driving coil, said drive pulse supply unit supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power;

a rotation detecting pulse supplying unit coupled to said driving coil and supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse; and

magnetic field pulse supplying unit coupled to said driving coil and supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, a magnetic field detection pulse being supplied prior to said driving pulse;

wherein said magnetic field pulse supplying unit supplies a first magnetic field detecting pulse to said driving coil prior to output of said driving pulse and a second magnetic field detecting pulse to said driving coil after output of said rotation detecting pulse.

40. The timepiece of claim 39 further comprising a detecting circuit coupled to said driving coil for comparing the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said stepping motor rotated and whether said magnetic field is present.

41. The timepiece of claim 40 further comprising an auxiliary pulse supplying unit coupled to said driving coil for supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said stepping motor in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

42. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving coil, said stepping motor being driven by driving pulses via said driving coil, an electricity generating device for generating electric power and causing a magnetic field during said generating of electric power, said electricity generating device being driven by a kinetic energy transferring unit, and an energy storing device for storing a voltage charge and supplying an electric power to the stepping motor, said control device comprising:

a magnetic field pulse supplying unit coupled to said driving coil unit and supplying a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, a magnetic field detection pulse being supplied prior to said driving pulse; and

a detecting circuit coupled to said driving coil and comparing the magnetic field detecting induction voltage with a second set value for determining whether said magnetic field is present;

wherein said detecting circuit adjusts said second set value used for evaluating said magnetic field detecting induction voltage based on said voltage charge stored in said energy storing device.

43. The timepiece of claim 42 further comprising a drive pulse supply unit coupled to said driving coil and supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power.

44. The timepiece of claim 43 further comprising a rotation detecting pulse supplying unit coupled to said driving coil and supplying a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said stepping motor, said rotation detection pulse being supplied following said driving pulse.

45. The timepiece of claim 44 further comprising an auxiliary pulse supplying unit connected to said driving coil and supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said stepping motor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

46. The timepiece of claim 45 further comprising an auxiliary pulse supplying unit connected to said driving coil and supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said stepping motor in response to output of said driving pulse, is not detected or when said external magnetic field has been detected.

47. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving coil, said stepping motor being driven by driving pulses via said driving coil, an electricity generating device for generating electric power and causing a magnetic field during said generating of said electric power, and applying said electric power to the control device, said control device comprising:

a drive pulse supply unit coupled to said driving coil and supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power; and

an auxiliary pulse supplying unit connected to said driving coil and supplying an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse;

said auxiliary pulse supplying unit providing said auxiliary pulse when said electricity generating device is generating the electric power.

48. The timepiece of claim 47, wherein said electricity generating device is driven by a kinetic energy transferring unit.

49. The timepiece of claim 47, further comprising an energy storing device for receiving the electric power.

50. A timepiece having a stepping motor, the stepping motor including a driving coil, said stepping motor being driven by driving pulses via said driving coil, an electricity generating device for generating electric power and causing a magnetic field during said generating of said electric power, said electricity generating device being driven by a kinetic energy transferring unit, and an energy storing device for receiving the electric power and applying said electric power to the control device, said control device comprising:

a short-pulse supplying unit connected to said driving coil and supplying a plurality of short-pulse pulses having a shorter cycle than said driving pulses to said driving coil;

wherein said short-pulse supplying unit stops supplying said short-pulse when said generating device is generating electricity.

51. The timepiece of claim 50 further comprising a drive pulse supply unit coupled to said driving coil and supplying a plurality of driving pulses to said driving coil for driving said stepping motor, said driving pulses having an effective electric power.

52. The timepiece of claim 50, wherein said plurality of short-pulse pulses includes at least one of either a fast-forward pulse or a reverse pulse.

53. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by a kinetic energy transfer unit, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

a driver to supply a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

a rotation detector to supply a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse;

a magnetic field detector to supply a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse;

an evaluator to compare the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present;

an auxiliary pulse supplier to supply an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected; and

wherein said driver supplies said driving pulses having a plurality of effective electric powers, and at least one of said driving pulses has a greater effective electric power than the effective electric power of an immediately preceding one of said driving pulses, said at least one of said driving pulses being supplied after said auxiliary pulse is supplied.

54. A timepiece comprising a control device for a stepping motor, the stepping motor including a driving rotor rotatably driveable near a driving stator, the driving stator having a driving coil, an electricity generating device for generating electric power, said electricity generating device having an electricity generating rotor that rotates near an electricity generating stator for generating electricity, said electricity generating device being driven by a kinetic energy transferring unit, and an energy storing device for receiving the electric power and applying magnetic force to the driving rotor, said control device comprising:

a driver to supply a plurality of driving pulses to said driving coil for driving said driving rotor, said driving pulses having an effective electric power;

a rotation detector to supply a rotation detection pulse for obtaining a rotation detection induction voltage for detecting the rotation of said driving rotor, said rotation detection pulse being supplied following said driving pulse;

a magnetic field detector to supply a plurality of magnetic field detection pulses for obtaining a magnetic field detecting induction voltage for detecting a magnetic field external to said stepping motor, said magnetic field detection pulse being supplied prior to said driving pulse;

an evaluator to compare the rotation detecting induction voltage and the magnetic field detecting induction voltage with a first set value and a second set value, respectively, for evaluating whether said driving rotor rotated and whether said magnetic field is present;

an auxiliary pulse supplier to supply an auxiliary pulse having an effective electric power that is greater than said effective electric power of said driving pulse, said auxiliary pulse being output when rotation of said driving rotor, in response to output of said driving pulse, is not detected or when said external magnetic field has been detected, said auxiliary pulse having a polarity; and

a demagnetizer to provide a demagnetizing pulse having a polarity that is different than said polarity of said auxiliary pulse, said demagnetizing pulse being output after said auxiliary pulse for demagnetizing said driving coil; and

wherein a following driving pulse is output following said auxiliary pulse, and said demagnetizing pulse is output immediately prior to said following driving pulse.