Back to results
US 4,954,741 AGranted
Control circuit for a vibration wave motor
AssigneeCanon Kabushiki Kaisha
InventorsEtsuro Furutsu, Kazuhiro Izukawa
Life of this patent
Estimating the term…
Abstract
In a speed control circuit for a vibration wave motor, when a level of a periodic signal applied to the motor is of first level, a frequency of the periodic signal is changed between a first frequency and a second frequency to change a speed between a first velocity and a second velocity, and when the frequency reaches the second frequency, the signal level is switched from the first level to the second level and the frequency is shifted by a predetermined amount toward the first frequency and then toward the second frequency so that the speed is changed from the second velocity to a third velocity.
Claims28
A control circuit for a vibration wave motor comprising:
- an electro-mechanical energy transducing element arranged on a vibration member;
- application means for applying periodic signals to said energy transducing element, said vibration member generating a driving force comprising a travelling vibration wave upon application of the periodic signals to said energy transducing element;
- a level adjuster for adjusting a level of the periodic signals;
- a frequency adjuster for adjusting a frequency of the periodic signals;
- and
- a switching circuit for switching the level of said level adjuster from a first level to a second level and for switching the frequency of said frequency adjuster from a first frequency to a second frequency when the frequency of said frequency adjuster has reached the first frequency during a period in which the level of said level adjuster is at the first level.
3 more elements
A control circuit for a vibration wave motor comprising:
- an electro-mechanical energy transducing element arranged on a vibration member;
- application means for applying periodic signals to said energy transducing element, said vibration member generating a driving force comprising a travelling vibration wave upon application of the periodic signals to said energy transducing element;
- a frequency adjuster for adjusting a frequency of the periodic signals;
- said frequency adjuster changing the frequency within a range between a first frequency and a second frequency when a motor speed is to be changed within a range between a first speed and a second speed and changing the frequency within a range between a third frequency shifted from the second frequency toward the first frequency, and a fourth frequency when the motor speed is to be changed within a range between the second speed and a third speed;
- and
- a level adjuster for adjusting a level of the periodic signals;
- said level adjuster changing the level to a first level when the motor speed is to be changed within the range between the first speed and the second speed, and changing the level to a second level when the motor speed is to be changed within the range between the second speed and the third speed.
4 more elements
A control circuit for a vibration wave motor comprising:
- (a) an electro-mechanical energy transducing element arranged on a vibration member;
- (b) application means for applying periodic signals to said energy transducing element,
- said vibration member generating a travelling vibration wave upon application of the periodic signals to said energy transducing element, to relatively drive a contact member contacted to said vibration member by the vibration wave;
- (c) a frequency information setting circuit;
- (d) a signal forming circuit for forming the periodic signals having the frequency determined by the frequency information set by said frequency information setting circuit;
- (e) update means for repeatedly updating the frequency information set by said frequency information setting circuit from a first frequency toward a second frequency to vary a motor speed;
- (f) shift means for shifting the frequency information set by said information setting circuit from the current setting toward the first frequency by a predetermined amount when the frequency of the periodic signals has reached the second frequency;
- the setting value of said information setting circuit being changed from the shifted setting value toward the second frequency by said update means after the shifted setting value has been set;
- and
- (g) a level switching circuit for switching a level of the periodic signals between a first level and a second level;
- said level switching circuit setting the periodic signals to the first level before the frequency is shifted by said shift means, and switching the level to the second level after the frequency has been shifted.
8 more elements
A control circuit for a vibration wave motor comprising:
- an electro-mechanical energy transducing element arranged on a vibration member;
- application means for applying periodic signals to said energy transducing element, said vibration member generating a driving force comprising a travelling vibration wave upon application of the periodic signals to said energy transducing element;
- a level adjuster for adjusting a level of the periodic signals;
- a frequency adjuster for adjusting a frequency of the periodic signals;
- and
- coordinating shifting means for shifting the level controlled by said level adjuster when the signal frequency adjusted by said frequency adjuster has become a predetermined value, and in coordination with the shifting of the signal level, for shifting the signal frequency adjusted by said frequency adjusters from said predetermined value.
3 more elements
A vibration wave motor device, comprising:
- an electro-mechanical energy transducing element arranged on a vibration member;
- an application means for applying periodic signals to said energy transducing element, said vibration member generating a driving force comprising a travelling vibration wave upon application of the periodic signals to said energy transducing element;
- first adjusting means for adjusting the frequency of said periodic signals as a first factor;
- second adjusting means for adjusting the level of said periodic signals as a second factor;
- and
- shifting means for shifting, when value of one of said two factors adjusted by one of said adjusting means shows a predetermined value, another value of said factors by another adjusting means and for shifting the value of the one of said factor from the predetermined value simultaneously.
3 more elements
Dependencies are inferred from the claim text.