Driving device of a vibration type actuator
AssigneeCanon Kabushiki Kaisha
InventorsTadashi Hayashi, Akio Atsuta, Kenichi Kataoka, Shinji Yamamoto, Jun Ito
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Abstract
A vibration type activator having improved electro-mechanical energy conversion efficiency and reduced noise generation includes plural switching elements each of which is operated by a switching pulse signal generated by a drive control circuit of the motor. A drive control circuit selects a pulse width of the generated switching pulse signal such that the amplitude of a base wave frequency component (“base wave”) among frequency components of a voltage applied to an inductance element may be larger than a total amplitude of higher harmonic wave frequency components (“whole higher harmonic wave”).
Claims19
A drving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy converifon element by applying a periodic signal to the ciectro-mechanical energy conversion element, comprising:
- a D.C. power source;
- a plurality of switching elements connected to said D.C. power source;
- an inductance element connected to said phniity of switching elements to raise a voltage level applied thereto;
- and
- a drive control circuit which generates a switching pulse signal for operating said plurality of switching elements,
- wherein each of said plwulity of switching elements is operated by the switching pulse signal generated by said drive control cfrcuit and the switching pulse signal generated by said drive control circuit has a pulse width selected so as to set an amplitude mdc of a base frequency component to a total amplitude of higher harmonic wave frequency components of a voltage applied to said inductance element to be approximately maximum.
A driving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy conversion element by applying a periodic signal to the electro-mechanical enerp conversion element Comprising:
- a D.C. power source;
- a plurality of switching elements connected to said D.C. power source;
- an inductance element connected to said plurality of switching elements to raise a voltage level applied thereto;
- and
- a drive confrol circuit which generates a switching pulse signal for operating said plurality of switching elemens,
- wherein said drive control circuit gradually incrnses a pulse width of the generated switching pulse signal from zero during a rising time, operates said plurality of switching elements by the switching pulse signal so that the drive control circuit sweeps the pulse width until an amplitude ratio of a base wave frequency component to a total amplitude of higher harmonic wave frequency components of a voltage applied to said inductance element is approximately maximum, and files the pulse width in this state.
A driving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy conversion element by applying a periodic signal to the electro-mechanical energy conversion element comprising:
- a D.C. power source;
- a plurality of plural switching elements connected to said D.C. power source;
- and
- a drive control circuit which generates a switching pulse signal for operating said plurality of switching elements,
- wherein each of said plurality of witching elements is operated by the switching pulse signal generated by said drive control circuit and the switching pulse signal generated by said drive control circuit has a pulse width selected so as to set an amplitude ratio of a base frequency component to a total amplitude of higher harmonic wave frequency components of a voltage applied to the electro-mechanical energy conversion element to be approximately maximum.
A driving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy conversion element by applying a periodic signal to the electro-mechanical energy conversion element comprising:
- a D.C. power source;
- a plurality of switching elements connected to said D.C. power source;
- and
- a drive control circuit which generates a switching pulse signal for operating said plurality of switching elements,
- wherein said drive control circuit gradually increases a pulse width of to generated switching pulse signal from zero during a rising time and operates said plurality of switching elements by applying the switching pulse signal no that the drive confrol circuit sweeps the pulse width until an amplitude ratio of a base wave frequency component to a total amplitude of higher harmonic wave frequency components of a voltage applied to the electro-mechanical energy conversion element is approximately maximum, and the drive control circuit fixes the pulse width in this state.
A driving device of a vibration type actuator which obtains driving force by applying a periodic signal to an electro-mechanical energy conversion element portion arranged in a vibration member, comprising:
- a switching element which is switched in response to a pulse signal;
- an inductance element through which an electric current intermittently flows by switching said switching element;
- a circuit which applies a voltage generated by intermittently flowing the decide current through said inductance element to said electro-mechanical energy conversion element portion;
- and
- a setting circuit that sets a duty cycle of said pulse signal such that a ratio of an amplitude of the base frequency component among frequency components of a voltage applied to said inductance element to a sum of amplitudes of all higher harmonic frequency components becomes approximately maximum.
A driving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy conversion element by applying a periodic signal to the electro-mechanical energy conversion element, comprising:
- a switching circuit having a switching element which is switched in response to a pulse signal;
- an inductance element connected to said switching circuit to raise a voltage level by switching operation of said switching element the periodic signal of the voltage level raised by said inductance clement being applied to said electro-mechanical energy conversion element;
- and
- a setting circuit that sets a duty of said pulse signal to duty in which a ratio of an amplitude of the base frequency component among frequency components of a voltage applied to said inductance element to a sum of amplitudes of all higher harmonic frequency components becomes approximately maximum.
A driving device of a vibration type actuator which obtains a driving force by exciting an electro-mechanical energy conversion element by applying a periodic signal to the electro-mechanical energy conversion element, comprising:
- a switching circuit having a switching element which is switched in response to a pulse signal and to which said electro-mechanical energy conversion element is connected, said periodic signal being applied to said electro-mechanical energy conversion element by a switching operation of said switching circuit;
- and
- a setting circuit that sets a duty cycle of said pulse signal to a duty cycle in which a ratio of an amplitude of the base frequency component among frequency components of a voltage applied to said electro-mechanical energy conversion element to a sum of amplitudes of all higher harmonic frequency components becomes approximately maximum.
A vibration type actuator including a vibration member, an electro-mechanical energy conversion element which generates vibration in the vibration member in response to a periodic signal applied to the electro-mechanical energy conversion element, and a driving device, said actuator comprising:
- a D.C. power source;
- a plurality of switching elements connected to said D.C. power source;
- an inductance element connected to said plurality of switching elements to raise a voltage level applied thereto;
- and
- a drive control circuit which generates a switching pulse signal for operating said plurality of switching elements,
- wherein each of said plurality of switching elements is operated by the switching pulse signal generated by said drive control circuit, and the switching pulse signal generated by said drive control circuit has a pulse width selected so as to set an amplitude ratio of a base frequency component to a total amplitude of higher harmonic wave frequency components of a voltage applied to said inductance element to be approximately maximum.
A vibration type actuator including a vibration member, an electro-mechanical energy conversion element which generates vibration in the vibration member in response to a periodic signal applied to the electro-mechanical energy conversion element, and a driving device, said actuator comprising:
- a switching circuit having a switching element which is switched in response to a pulse signal;
- an inductance element connected to said switching circuit to raise a voltage level by switching operation of said switching element, the periodic signal of the voltage level raised by said inductance element being applied to said electro-mechanical energy conversion element;
- and
- a setting circuit that sets a duty of the pulse signal to a duty in which a ratio of an amplitude of the base frequency component among frequency components of a voltage applied to said inductance element to a sum of amplitudes of all higher harmonic frequency components becomes approximately maximum.
Dependencies are inferred from the claim text.