Driving apparatus of vibration type actuator
AssigneeCanon Kabushiki Kaisha
InventorsTadashi Hayashi, Shinji Yamamoto
Life of this patent
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Abstract
This invention relates to a driving apparatus of a vibration type actuator, and provides an apparatus for forming a vibration wave by applying four-phase AC signals having temporal phase differences to four-phase driving phases arranged at intervals of ¼ a wavelength, which includes first and second transformers and two-phase driving phases connected to the secondary terminals of the respective transformers, thereby simplifying the arrangement of a driving circuit.
Claims21
A driving apparatus of a four-phase driving vibration type actuator for applying four-phase AC signals having temporal phase differences to four-phase driving phases arranged on an electro-mechanical energy conversion element of a vibration member at intervals of ¼ a wavelength of a resonance vibration, thereby forming a travelling wave by synthesizing a standing wave formed by one pair of two-phase driving phases at a position of a half wavelength with a standing wave formed by the other pair of two-phase driving phases, comprising:
- a pulse generating circuit for generating a pulse in accordance with a driving frequency;
- a first switching circuit for outputting an AC voltage to a first transformer by ON/OFF-controlling a switching element in accordance with a pulse from said pulse generating circuit;
- and
- a second switching circuit for outputting an AC voltage to a second transformer by ON/OFF-controlling the switching element in accordance with a pulse from said pulse generating circuit,
- wherein said one pair of two-phase driving phases are respectively connected to two ends of a secondary side of the first transformer, said other pair of two-phase driving phases are respectively connected to two ends of the secondary side of the second transformer, and said pulse generating circuit outputs pulses to said first and second switching circuits with a phase difference of 90°.
A driving apparatus of a vibration type actuator for generating a standing wave by applying an AC signal to an electro-mechanical energy conversion element of a vibration member, comprising:
- a transformer for outputting an AC voltage:
- and
- an inductor formed on a secondary side of said transformer, said inductor being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of said inductor and a capacitance of the electro-mechanical energy conversion element, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for generating a standing wave by applying two-phase AC signals having a temporal phase difference of 180° to two-phase driving phases arranged on an electro-mechanical energy conversion element of a vibration member at intervals of ½ a wavelength of resonance vibrations, comprising
- a transformer for outputting an AC voltage, said transformer having two inductors on a secondary side to drive two-phase driving phases and being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of said inductors and a capacitance of one phase of the electro-mechanical energy conversion element, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for generating a standing wave by applying an AC signal to an electro-mechanical energy conversion element of a vibration member, comprising
- a transformer for outputting an AC voltage, said transformer having two inductors on a secondary side of said transformer to drive two-phase driving phases and an adjustment capacitor added thereto, and said transformer being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of the inductor and a sum of a capacitance of the electro-mechanical energy conversion element and a capacitance of the adjustment capacitor, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for generating a standing wave by applying two-phase AC signals having a temporal phase difference of 180° to two-phase driving phases arranged on an electro-mechanical energy conversion element of a vibration member at intervals of ½ a wavelength of resonance vibrations, comprising
- a transformer for outputting an AC voltage, said transformer having two inductors on a secondary side to drive two-phase driving phases and an adjustment capacitor added thereto, and said transformer being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of the inductor and a sum of a capacitance of the electro-mechanical energy conversion element and a capacitance of the adjustment capacitor, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for forming a travelling wave by synthesizing a plurality of standing waves formed by applying AC signals with a temporal phase difference to an electro-mechanical energy conversion element of a vibration member, comprising:
- first and second transformers for generating AC voltages;
- and
- two inductors respectively formed on secondary sides of said first and second transformers, said inductors being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of said inductors and a capacitance of the electro-mechanical energy conversion element, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration driving type actuator for forming a travelling wave by synthesizing a standing wave formed by one pair of two-phase driving phases with a standing wave formed by the other pair of two-phase driving phases, which have a positional relationship represented by a half wavelength with respect to a wavelength of resonance vibrations, by applying four-phase AC signals having temporal phase differences from each other to four-phase driving phases arranged on an electro-mechanical energy conversion element of a vibration member at intervals of ¼ the wavelength of resonance vibrations, comprising:
- first and second transformers for generating AC voltages, said first and second transformers having two inductors formed on secondary sides of said first and second transformers to drive two-phase driving phases and being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of said inductors and a capacitance of one phase of the electro-mechanical energy conversion element, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for forming a plurality of standing waves by applying AC signals with a temporal phase difference to an electro-mechanical energy conversion element of a vibration member and forming a travelling wave by synthesizing the standing waves, comprising:
- first and second transformers for generating AC voltages, said first and second transformers having inductors on secondary sides and adjustment capacitors added thereto, and said transformer being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of the inductor and a sum of a capacitance of the electro-mechanical energy conversion element and a capacitance of the adjustment capacitor, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
A driving apparatus of a vibration type actuator for forming a travelling wave by synthesizing a standing wave formed by one pair of two-phase driving phases with a standing wave formed by the other pair of two-phase driving phases, which have a positional relationship represented by a half wavelength with respect to a wavelength of resonance vibrations, by applying four-phase AC signals having temporal phase differences from each other to four-phase driving phases arranged on an electro-mechanical energy conversion element of a vibration member at intervals of ¼ the wavelength of resonance vibrations, comprising:
- first and second transformers for generating AC voltages, said first and second transformers having two inductors formed on secondary sides of said first and second transformers to drive two-phase driving phases and adjustment capacitors added thereto, and said transformer being set to satisfy
- fr<(fre/{square root}{square root over (2)})<fs
- where fre is a parallel resonance frequency of an inductance of the inductor and a sum of a capacitance of the electro-mechanical energy conversion element and a capacitance of the adjustment capacitor, fr is a resonance frequency of the vibration member, and fs is a frequency at which a vibration amplitude of the vibration member increases for the first time in a region higher than the resonance frequency fr.
Dependencies are inferred from the claim text.