DRIVE APPARATUS, DRIVE METHOD, AND OPTICAL DEVICE
1 Assignment
0 Petitions
Accused Products
Abstract
Noise produced during phase-difference changes is minimized without decreasing the responsiveness of a vibration-wave motor. A lens-side MCU (15) for a lens barrel (10) controls a drive apparatus (14) that applies a drive voltage to the vibration-wave motor (12) by outputting an A-phase drive signal and a B-phase drive signal thereto. The lens-side MCU (15) uses, for example, a drive-voltage setting unit (152) and a duty-cycle change unit (153) to change the drive voltage. Also, the lens-side MCU (15) is provided with a phase-difference change unit (154) that changes the phase difference between the A-phase drive signal and the B-phase drive signal. When driving the vibration-wave motor (12), the lens-side MCU (15) changes the drive voltage to Vreg, and when the phase-difference change unit (154) is changing the aforementioned phase difference, the drive voltage is changed to V1, V1 being greater than zero and less than Vreg.
7 Citations
58 Claims
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1-29. -29. (canceled)
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30. An optical device comprising:
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a vibration actuator for which a driving direction changes according to a phase difference between a first drive signal and a second drive signal; a drive apparatus that applies a drive voltage to the vibration actuator by outputting the first drive signal and the second drive signal; a drive voltage change unit that changes the drive voltage; and a phase difference change unit that changes the phase difference, wherein the drive voltage change unit changes the drive voltage to a first voltage in a case of driving the vibration actuator, and changes the drive voltage to a second voltage that is greater than 0 and less than the first voltage in a case of the phase difference change unit changing the phase difference. - View Dependent Claims (31, 32, 33, 34)
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35. A drive apparatus, comprising:
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a signal generation unit that generates a pair of drive signals; an electro-mechanical conversion element to which the drive signals generated by the signal generation unit are applied; a vibrating body that generates a drive force by way of vibration of the electro-mechanical conversion element; a moving body that is under pressurized contact with the vibrating body and is driven by way of the drive force; and a control unit that sets a frequency and phase difference of the drive signals, wherein the control unit changes the phase difference after setting the frequency to a holding frequency at which a drive speed of the moving body becomes substantially zero, when changing a driving direction of the moving body. - View Dependent Claims (36, 37, 38, 39)
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40. An optical device, comprising:
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vibration actuator that drive a lens using a drive force generated at a driving face by way of excitation of an electro-mechanical conversion element; a drive control unit that provides two drive signals to the vibration actuator; and a photography setting unit that can select a moving image photography mode, wherein the drive control unit can change a speed of the vibration actuator, in a case of the photography setting unit selecting the moving image photography mode, by changing a phase difference of the two drive signals, and changing a frequency of the two drive signals to correspond to the phase difference thus changed, while maintaining a voltage of the two drive signals to be constant. - View Dependent Claims (41, 42, 43, 44)
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45. A drive apparatus, comprising:
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a vibrating part having an electro-mechanical energy conversion element to which two drive signals having variable phase difference are inputted; a relative motion part that relatively moves in relation to the vibrating part, by way of a drive force generate at the vibrating part by according to vibration of the electro-mechanical energy conversion element; and a control unit that inputs the two drive signals to the electro-mechanical energy conversion element at a startup frequency that is higher than a drive frequency used in driving, while maintaining at phase difference at which the relative motion part is in a stopped state, and when gradually reducing the frequency of the two drive signals from the startup frequency and reaching the drive frequency, sets the phase difference to a phase difference that enables the relative motion part to relatively move in relation to the vibrating part. - View Dependent Claims (46, 47, 49)
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48. A method of driving a vibration actuator, wherein the vibration actuator comprises:
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a vibrating part having an electro-mechanical energy conversion element to which two drive signals having variable phase difference are inputted; and a relative motion part that relatively moves in relation to the vibrating part, by way of a drive force generated at the vibrating part according to vibration of the electro-mechanical energy conversion element, the method comprising the steps of; during startup of the vibration actuator, inputting the two drive signals to the electro-mechanical energy conversion element in a state maintaining a phase difference therebetween at a phase difference at which the relation motion part stays in a stopped state, and at a startup frequency that is higher than the drive frequency used in driving of the vibration actuator; and setting the phase difference to a phase difference at which the relation motion part can relatively move in relation to the vibrating part, upon gradually reducing the frequency of the two drive signals from the startup frequency and reaching the drive frequency.
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50. A drive apparatus for controlling driving of a vibration actuator that generates a drive force, by applying two-phase alternating signals having different phases to a piezeoelectric body provided to a vibrating body to cause the vibrating body to vibrate, the drive apparatus comprising:
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a speed control unit that controls a drive speed of the vibration actuator, by causing a frequency of the two-phase alternating signals applied to the piezoelectric body to change; a frequency storage unit that stores a predetermined frequency; and a stop determination unit that determines whether the vibration actuator is stopped, wherein the speed control unit causes the frequency of the alternating signals applied to the piezoelectric body to change to the predetermined frequency stored in the frequency storage unit, in a case of the stop determination unit having determined that the vibration actuator is stopped. - View Dependent Claims (56, 57)
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51. A drive apparatus that controls driving of a vibration actuator that generates a drive force, by applying two-phase alternating signals having different phases to a piezeoelectric body provided to a vibrating body, the drive apparatus comprising:
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a speed control unit that controls a drive speed of the vibration actuator, by causing a frequency of the two-phase alternating signals applied to the piezoelectric body to change; and a stop determination unit that determines whether the vibration actuator is stopped, wherein the speed control unit causes the frequency of the alternating signals applied to the piezoelectric body to change so as to approach an electrical resonance frequency, in a case of the stop determination unit having determined that the vibration actuator is stopped. - View Dependent Claims (52, 53, 54, 55)
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58. An optical device, comprising:
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an electro-mechanical energy conversion element to which a drive signal is applied from a drive circuit; a vibrating body that generates a drive force by way of the electro-mechanical energy conversion element; a moving body that is driven by the drive force of the vibrating body; and a control unit that performs first control to control so that the drive signal becomes a first frequency when causing the moving body to drive, and performs second control to control so that the drive signal becomes a second frequency when the moving body is stopped, wherein the drive circuit has a smaller amount of power consumption when the drive signal is the second drive signal than when the drive signal is the first drive signal.
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Specification