JP2020025412A - Actuator driving circuit and electronic apparatus - Google Patents

Abstract

To provide an actuator driving circuit in which phase control is accurately performed with a simple circuit configuration.SOLUTION: An actuator driving circuit 1 includes displacement elements 23A, 23B for causing predetermined displacement, a synthesis unit 24 that is coupled to the displacement elements 23A, 23B and is driven by the displacement caused by the displacement elements 23A, 23B, and a rotor 25 that is driven by the synthesis unit 24 coming into contact with the rotor. The actuator driving circuit includes drivers 11 that apply driving signals to one of the displacement elements 23A, 23B, detectors 15 that detect detection signals from the other one of the displacement elements 23A, 23B, an integration region pulse generation circuit 44 that generates integration region pulses each shifted by a predetermined phase from the driving signal, an integration circuit 54 that integrates the detection signals by using the integration region pulses, and a VCO 42 that controls the frequencies of the driving signals by using, as a phase comparison output, an output signal from the integration circuit 54.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an actuator drive circuit and an electronic device.

  Conventionally, in the field of truss-type actuators, a technique is known in which a chip member is provided at the intersection of three stacked piezoelectric elements, the chip member is driven so as to draw an ellipse, and the spherical driven member is turned in an arbitrary direction. Have been. The solution to the abstract of Patent Document 1 includes “an oscillator 10 for adjusting the vibration frequency of each of the displacement units 2 and 3, AGCs 12 and 13 for adjusting the vibration amplitude of each of the displacement units 2 and 3, and power amplifiers 14 and 15. A phase shifter 11 for adjusting a vibration phase difference between each of the displacement units 2 and 3, and an amplitude detection unit 19, 20 and a phase difference detection unit 18 for detecting an amplitude and a phase difference of each of the vibrating displacement units 2 and 3. And, based on the detected amplitude and the detected phase difference, at least one of the amplitude adjusted by the AGC 12 or the like and the power amplifier 14 or the phase difference adjusted by the phase shifter 11 to change the elliptical locus of the combining unit. And an MPU 21 for adjustment. "

FIG. 10 is a configuration diagram schematically illustrating an example of an actuator drive circuit.
The drive circuit 1B is connected to the truss-type actuator 2, and drives the actuator 2 to rotate. The actuator 2 includes a pressing unit 21, a fixed unit 22, displacement elements 23A and 23B, a combining unit 24 respectively coupled to the displacement elements 23A and 23B, and a rotor 25. The fixing part 22 adheres and fixes the base ends of the displacement elements 23A and 23B such that the distal ends of the displacement elements 23A and 23B are orthogonal to each other. The displacement elements 23A and 23B generate a predetermined displacement by the drive circuit 1B. The combining section 24 is adhered to the orthogonal portions at the tips of the displacement elements 23A and 23B. The rotor 25 is a driven member driven by the contact of the combining unit 24. The fixing portion 22, the displacement elements 23A and 23B, and the combining portion 24 constitute a truss structure.

  The pressing unit 21 presses the truss structure including the fixing unit 22, the displacement elements 23 </ b> A and 23 </ b> B, and the combining unit 24 in the direction of the rotor 25, and thus brings the combining unit 24 into pressure contact with the rotor 25. As the displacement elements 23A and 23B, laminated piezoelectric elements that convert electric signals into displacement by a piezoelectric effect are used. For the combining portion 24, a metal material such as tungsten, which is stably provided with a high friction coefficient and is hard to wear, is used. The fixing portion 22 is made of a metal material such as stainless steel which can be easily manufactured and has high strength. In addition, an epoxy resin adhesive excellent in adhesive strength and strength is used for the bonding. The pressing unit 21 is configured by a coil spring or the like, and presses the fixed unit 22 toward the center of a disk-shaped rotor 25 that is a driven member. The rotor 25 is made of a metal such as iron or aluminum, and has a side surface subjected to a surface treatment such as a tuftride treatment or an alumite treatment in order to prevent abrasion due to contact with the combining portion 24.

  In the single-phase drive system, a drive signal is given to only one of the displacement elements 23A and 23B to generate an elliptical vibration in the truss structure. The resonance frequency generated by vibrating the truss structure has a plurality of vibration modes. By controlling this frequency, the drive circuit 1B simultaneously generates lateral vibration and longitudinal vibration to induce elliptical vibration, and rotates the rotor 25 by the elliptical vibration. Electrical control is performed using the fact that the inclination of the elliptical vibration becomes substantially equal to the current phase difference.

A VCO (Voltage-controlled oscillator) 42 outputs a drive clock having a frequency according to the applied voltage. The pulse generation circuit 43 generates a rectangular pulse based on the drive clock output from the VCO 42. This rectangular pulse is output to the A-phase circuit and the B-phase circuit.
The drive circuit 1B is roughly classified into an A-phase circuit that supplies a drive signal to the displacement element 23A and a B-phase circuit that supplies a drive signal to the displacement element 23B.
The A-phase circuit includes a driver 11A, an LC filter 12A, an interlocking switch 13A that interlocks complementarily with the B-phase interlocking switch 13B, a current detection resistor 14A, a detector 16A, and a hysteresis correction circuit 31A. This driver 11A is configured by bridge-connecting two amplifiers. The output signal of the pulse generation circuit 43 is input to the input side of the driver 11A. The driver 11A outputs a signal obtained by amplifying the signal from a first output terminal, and outputs a signal obtained by amplifying and inverting the signal from a second output terminal. The first output terminal and the second output terminal of the driver 11A are connected to the LC filter 12A. An interlock switch 13A is connected to two output terminals of the LC filter 12A. When the interlock switch 13A is open, a sine wave signal is output from the output terminal of the LC filter 12A. When the interlock switch 13A is closed, no signal is output from the output terminal of the LC filter 12A.

One output terminal of the LC filter 12A is connected to one end of the displacement element 23A, and the other output terminal is connected to the other end of the displacement element 23A via the current detection resistor 14A.
The detector 16A detects and compares the voltage between both ends of the current detection resistor 14A with a comparator, and thus detects the current flowing through the displacement element 23A. The output signal of the detector 16A is binarized.
The output signal of the detector 16A is input to the hysteresis correction circuit 31A and then to the selector 32. The hysteresis correction circuit 31A removes erroneous detection pulses included in the current signal by digital processing.

  Similarly, the B-phase circuit includes a driver 11B, an LC filter 12B, an interlocking switch 13B that interlocks complementarily with the A-phase interlocking switch 13A, a current detection resistor 14B, a detector 16B, and a hysteresis correction circuit 31B. Prepare. The B-phase circuit is connected in the same manner as the A-phase circuit.

  Hereinafter, when the drivers 11A and 11B are not distinguished from each other, they are simply referred to as the driver 11. When the LC filters 12A and 12B are not distinguished, they are simply described as the LC filter 12. When the interlock switches 13A and 13B are not distinguished, they are simply described as the interlock switch 13. When the current detection resistors 14A and 14B are not distinguished, they are simply described as the current detection resistor 14. When the detectors 16A and 16B are not distinguished, they are simply described as the detector 16.

  When the A-phase circuit drives the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit does not drive the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a driving signal, and the current flowing through the displacement element 23B is a non-driving signal. The A-phase hysteresis correction circuit 31A binarizes the current flowing through the displacement element 23A and outputs a drive-side phase signal. The B-phase hysteresis correction circuit 31B binarizes the current flowing through the displacement element 23B and outputs a non-drive-side phase signal.

  When the A-phase circuit does not drive the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit drives the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a non-drive-side signal, and the current flowing through the displacement element 23B is a drive-side signal. The A-phase hysteresis correction circuit 31A binarizes the current flowing through the displacement element 23A and outputs a non-drive-side phase signal. The B-phase hysteresis correction circuit 31B binarizes the current flowing through the displacement element 23B and outputs a drive-side phase signal.

  The selector 32 outputs the phase signal detected in the phase on the driving side to the phase difference setting circuit 33, and outputs the phase signal detected in the phase on the non-driving side to the phase comparator 34 as it is. The phase difference setting circuit 33 delays the phase signal by a target phase difference and outputs it. In FIG. 10, since the A-phase is the drive side, the phase signal of the A-phase is delayed by 45 ° (see FIG. 11).

  Thereafter, the phase comparator 34 compares the phase signal on the driving side with the phase signal on the non-driving side, and feeds it back to the VCO 42 via the low-pass filter 41. Thereby, the drive circuit 1B can control the current waveform of the displacement element 23A on the drive side and the current waveform of the displacement element 23B on the non-drive side so as to have a target phase difference.

FIG. 11 is a waveform diagram showing a phase comparison operation from the driving-side phase signal and the non-driving-side phase signal.
The first graph shows the driving-side signal. The drive-side signal is a current flowing through the A-phase displacement element 23A (see FIG. 10).
The second graph shows the non-driving side signal. The non-drive side signal is a current flowing through the B-phase displacement element 23B (see FIG. 10), and is behind the drive side signal by 45 ° in the steady state of feedback.

The third graph shows the phase signal on the drive side after the hysteresis correction. This phase signal is an output signal of the hysteresis correction circuit 31A (see FIG. 10), and is delayed by an angle Φ from the zero cross of the driving signal.
The fourth graph shows the phase signal on the non-drive side after the hysteresis correction. This phase signal is an output signal of the hysteresis correction circuit 31B (see FIG. 10), and is delayed by an angle Φ with respect to the zero cross of the non-drive-side signal.

  The fifth graph shows the waveform of the drive-side phase signal after setting the phase difference. This phase signal is an output signal of the phase difference setting circuit 33, and is delayed by 45 ° from the phase signal on the driving side.

FIG. 12 is a waveform diagram showing a driving-side phase signal, a non-driving-side phase signal, and a phase comparison output signal at a phase difference of 0 °.
The first graph shows the drive-side phase signal after hysteresis correction, and rises at time t0 and time t1.
The second graph shows the non-drive-side phase signal after the hysteresis correction, and rises at time t0 and time t1. The phase comparison signal is a signal obtained by comparing the rising edge of the phase signal on the driving side with the rising edge of the phase signal on the non-driving side. Here, the phase difference is 0 °, and both signals rise simultaneously, so that the phase comparison signal is always 0.

FIG. 13 is a waveform diagram showing a driving-side phase signal, a non-driving-side phase signal, and a phase comparison output signal in the leading phase.
The first graph shows the drive-side phase signal after the hysteresis correction, and rises at time t11 and time t13.
The second graph shows the phase signal on the non-driving side after the hysteresis correction, and rises at time t10 and time t12. The phase comparison signal is a signal obtained by comparing the rising edge of the phase signal on the driving side with the rising edge of the phase signal on the non-driving side. Here, since the non-driving side has an advanced phase, the phase comparison signal becomes a positive pulse at times t10 to t11 and becomes a positive pulse at times t12 to t13.

FIG. 14 is a waveform diagram showing a non-driving-side phase signal of the driving-side phase signal and the phase comparison output signal in the delay phase.
The first graph shows the drive-side phase signal after the hysteresis correction, and rises at time t20 and time t22.
The second graph shows the phase signal on the non-drive side after the hysteresis correction, and rises at time t21 and time t23. The phase comparison signal is a signal obtained by comparing the rising edge of the phase signal on the driving side with the rising edge of the phase signal on the non-driving side. Here, since the non-driving side has a lag phase, the phase comparison signal becomes a negative pulse from time t20 to t21 and becomes a negative pulse from time t22 to t23.

JP-A-2002-112563

  As described above, in the phase comparison in the conventional single-phase driving, it is necessary to remove the erroneous detection pulse included in the binarized phase signal. Further, since this phase comparison operation is complicated, there are problems that many circuits such as a hysteresis correction circuit, a phase comparator, and a low-pass filter are required, and it is difficult to secure the accuracy of the phase control.

  Therefore, an object of the present invention is to perform accurate phase control of an actuator drive circuit with a simple circuit configuration.

The present invention, in order to achieve the above object,
A plurality of displacement elements for generating a predetermined displacement,
A driving member coupled to the plurality of displacement elements and driven by displacement of the plurality of displacement elements;
A driven member driven by the contact of the driving member,
An actuator drive circuit comprising:
A drive unit that applies a drive signal to one of the plurality of displacement elements, and a detection unit that detects a detection signal from the other one of the plurality of displacement elements.
A pulse generation unit that generates an integration region pulse shifted by a predetermined phase from the drive signal;
An integration unit that integrates the detection signal using the integration region pulse;
A voltage control unit that controls the frequency of the drive signal, using the output signal of the integration unit as a phase comparison output,
An actuator drive circuit comprising:

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform a precise phase control with a simple circuit structure about an actuator drive circuit.

FIG. 2 is a configuration diagram schematically illustrating an actuator drive circuit according to the first embodiment. FIG. 9 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal at a phase difference of 0 °, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set. FIG. 7 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal in a leading phase, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set. FIG. 9 is a waveform diagram illustrating a drive pulse generation signal and a drive-side amplifier output signal, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set in a lag phase. It is a block diagram showing the outline of the actuator drive circuit in a 2nd embodiment. FIG. 9 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal at a phase difference of 0 °, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set. FIG. 7 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal in a leading phase, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set. FIG. 9 is a waveform diagram illustrating a drive pulse generation signal and a drive-side amplifier output signal, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set in a lag phase. FIG. 7 is a waveform diagram showing a drive pulse generation signal, a drive-side amplifier output signal and an integration region pulse, and a non-drive-side amplifier output signal and an integration region pulse in a phase-lag state. FIG. 2 is a configuration diagram schematically illustrating an example of an actuator drive circuit. FIG. 9 is a waveform diagram illustrating a phase comparison operation from a driving-side phase signal and a non-driving-side phase signal. FIG. 9 is a waveform diagram showing a driving-side phase signal, a non-driving-side phase signal, and a phase comparison output signal at a phase difference of 0 °. FIG. 4 is a waveform diagram showing a driving-side phase signal, a non-driving-side phase signal, and a phase comparison output signal in a leading phase. FIG. 7 is a waveform diagram showing a non-driving side phase signal with a driving side phase signal in a lag phase and a phase comparison output signal.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
<< 1st Embodiment >>
The essential points of the first embodiment include an integration region pulse generation circuit that generates an integration region pulse arbitrarily shifted from the drive signal, and an integration circuit that integrates the current detection signal using the integration region pulse. Is fed back to the VCO as a phase comparison output. Hereinafter, the first embodiment will be described with reference to FIGS.

FIG. 1 is a configuration diagram schematically illustrating an actuator drive circuit according to the first embodiment.
The drive circuit 1 according to the first embodiment is connected to a truss-type actuator 2 and drives the actuator 2 to rotate. The actuator 2 includes a pressing unit 21, a fixed unit 22, displacement elements 23A and 23B, a combining unit 24 respectively coupled to the displacement elements 23A and 23B, and a rotor 25. The fixing part 22 adheres and fixes the base ends of the displacement elements 23A and 23B such that the distal ends of the displacement elements 23A and 23B are orthogonal to each other. The displacement elements 23A and 23B cause the drive circuit 1 to generate a predetermined displacement. The synthesizing unit 24 is bonded (coupled) to the orthogonal portions of the distal ends of the displacement elements 23A and 23B, and functions as a driving member driven by the displacement of the displacement elements 23A and 23B. The rotor 25 is a driven member driven by the contact of the combining unit 24. The fixing portion 22, the displacement elements 23A and 23B, and the combining portion 24 constitute a truss structure.

  The pressing unit 21 presses the truss structure including the fixing unit 22, the displacement elements 23 </ b> A and 23 </ b> B, and the combining unit 24 in the direction of the rotor 25, and thus brings the combining unit 24 into pressure contact with the rotor 25. As the displacement elements 23A and 23B, laminated piezoelectric elements that convert electric signals into displacement by a piezoelectric effect are used. For the combining portion 24, a metal material such as tungsten, which is stably provided with a high friction coefficient and is hard to wear, is used. For the fixing portion 22, a metal material such as stainless steel, which is easy to manufacture and has high strength, is used. In addition, an epoxy resin adhesive excellent in adhesive strength and strength is used for the bonding. The pressing unit 21 is configured by a coil spring or the like, and presses the fixed unit 22 toward the center of a disk-shaped rotor 25 that is a driven member. The rotor 25 is made of a metal such as iron or aluminum, and has a side surface subjected to a surface treatment such as a tuftride treatment or an alumite treatment in order to prevent abrasion due to contact with the combining portion 24.

Hereinafter, the phase comparison operation of the single-phase drive circuit in the truss-type actuator of the first embodiment will be briefly described.
The VCO 42 outputs a drive clock having a frequency according to the applied voltage. The pulse generation circuit 43 generates a rectangular pulse based on the drive clock output from the VCO 42. The rectangular pulse is output to the A-phase circuit, the B-phase circuit, and the integration area pulse generation circuit 44.
The drive circuit 1 is roughly classified into an A-phase circuit that supplies a drive signal to the displacement element 23A, and a B-phase circuit that supplies a drive signal to the displacement element 23B.

  The A-phase circuit includes a driver 11A, an LC filter 12A, an interlock switch 13A that interlocks complementarily with the B-phase interlock switch 13B, a current detection resistor 14A, and a detector 15A. This driver 11A is configured by bridge-connecting two amplifiers. The output signal of the pulse generation circuit 43 is input to the input side of the driver 11A. The driver 11A outputs a signal obtained by amplifying the signal from a first output terminal, and outputs a signal obtained by amplifying and inverting the signal from a second output terminal.

  The first output terminal and the second output terminal of the driver 11A are connected to the LC filter 12A. An interlock switch 13A is connected to two output terminals of the LC filter 12A. When the interlock switch 13A is open, a sine wave signal is output from the output terminal of the LC filter 12A. When the interlock switch 13A is closed, no signal is output from the output terminal of the LC filter 12A.

One output terminal of the LC filter 12A is connected to one end of the displacement element 23A, and the other output terminal is connected to the other end of the displacement element 23A via the current detection resistor 14A.
The detector 15A detects the voltage across the current detection resistor 14A by analog amplification and detects the current flowing through the displacement element 23A. The output signal of the detector 15A is input to the selector 53.

  Similarly, the B-phase circuit includes a driver 11B, an LC filter 12B, an interlocking switch 13B that interlocks complementarily with the A-phase interlocking switch 13A, a current detection resistor 14B, and a detector 15B. The B-phase circuit is connected in the same manner as the A-phase circuit.

  When the A-phase circuit drives the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit does not drive the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a driving signal, and the current flowing through the displacement element 23B is a non-driving signal.

  When the A-phase circuit does not drive the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit drives the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a non-drive-side signal, and the current flowing through the displacement element 23B is a drive-side signal.

  The selector 53 outputs a detection signal (analog signal) of the phase on the non-driving side to the integration circuit 54. The integration region pulse generation circuit 44 generates an integration region pulse by advancing the phase of the drive pulse generation signal by 45 °. If the integration area pulse is at the H level, the integration circuit 54 integrates the non-drive side detection signal. That is, the integration circuit 54 integrates the non-drive side detection signal corresponding to the section (predetermined section) where the integration region pulse is at the H level. The operation of the integration circuit 54 will be described with reference to FIGS.

FIG. 2 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal at a phase difference of 0 °, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive-side detection signal. This drive-side detection signal is a sine wave and is an output signal of the detector 15A in FIG. At time t31, which is the edge of the drive pulse generation signal, the drive-side detection signal crosses zero.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-driving side.
Time t30 is the rising edge of the integration region pulse and is the start time of integration. At time t30, the phase is advanced by 45 ° with respect to time t31, which is the zero cross point of the drive side detection signal. Time t33 is the falling edge of the integration area pulse and is the end time of the integration. At time t33, the phase is delayed by 180 ° with respect to time t30.

  In FIG. 2, the phase difference between the detection signal on the non-drive side and the detection signal on the drive side is 45 °. At time t32, which is the zero-cross point of the non-drive-side detection signal, the phase is delayed by 45 ° with respect to the zero-cross point of the drive-side detection signal, and the phase is delayed by 90 ° with respect to time t30. Therefore, the positive region and the negative region are equal in the integration region of the detection signal on the non-driving side.

FIG. 3 is a waveform diagram showing the drive pulse generation signal and the drive-side amplifier output signal in the leading phase, the non-drive-side amplifier output signal, and the integration region pulse when the phase difference is set to 45 °.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive side detection signal. This drive-side detection signal is a sine wave and is an output signal of the detector 15A in FIG. At time t41, which is the edge of the drive pulse generation signal, the drive-side detection signal crosses zero.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-driving side.
Time t40 is the rising edge of the integration region pulse and is the start time of the integration. At time t40, the phase is advanced by 45 ° with respect to time t41, which is the zero cross point of the drive-side detection signal. Time t43 is the falling edge of the integration region pulse and is the end time of the integration. At time t43, the phase is delayed by 180 ° from time t40.

  In FIG. 3, the phase of the detection signal on the non-driving side is advanced by approximately 45 ° with respect to the original phase (see the third graph in FIG. 2). Time t42, which is the zero-cross point of the non-drive-side detection signal, is near the zero-cross point of the drive-side detection signal, and has a phase lag of 45 ° with respect to time t30. Therefore, in the integration region of the detection signal on the non-drive side, the positive region is larger than the negative region.

FIG. 4 is a waveform diagram showing the drive pulse generation signal and the drive-side amplifier output signal, the non-drive-side amplifier output signal, and the integration region pulse when the phase difference is set to 45 ° in the delay phase.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive-side detection signal. This drive-side detection signal is a sine wave and is an output signal of the detector 15A in FIG. At time t51, which is the edge of the drive pulse generation signal, the drive-side detection signal crosses zero.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-driving side.
Time t50 is the rising edge of the integration region pulse and is the start time of the integration. At time t50, the phase is advanced by 45 ° with respect to time t51, which is the zero cross point of the drive-side detection signal. Time t53 is the falling edge of the integration area pulse and is the end time of the integration. At time t53, the phase is delayed by 180 ° with respect to time t50.

  In FIG. 4, the phase of the detection signal on the non-drive side is delayed by approximately 45 ° from the original phase (see the third graph in FIG. 2). At time t52, which is the zero-cross point of the detection signal on the non-drive side, the phase is delayed by substantially 90 ° with respect to the zero-cross point of the detection signal on the drive side, and the phase is delayed by 135 ° with respect to time t50. Therefore, in the integration region of the detection signal on the non-drive side, the positive region is larger than the negative region.

  Returning to FIG. 1, the description will be continued. The integration circuit 54 feeds back an output signal that is the integration value to the VCO 42. Thus, the drive circuit 1 can control the current waveform of the driving-side displacement element 23A and the current waveform of the non-driving-side displacement element 23B so as to have a target phase difference (45 °).

When the sum of the detection signals on the non-drive side is not 0 and takes a positive value in the integration region of the detection signal on the non-drive side, the drive circuit 1 outputs a current waveform output from the VOC 42 to the displacement element 23B on the drive side. Is controlled to advance the phase of.
In addition, when the sum of the non-drive-side detection signals is not 0 and takes a negative value in the integration region of the non-drive-side detection signals, the drive circuit 1 outputs the sum from the VOC 42 to the drive-side displacement element 23B. Control is performed to delay the phase of the current waveform.

<< Effect of 1st Embodiment >>
The drive circuit 1 of the present invention integrates a current detection signal using an integration area pulse phase-shifted from a drive pulse. As a result, the number of circuits such as the hysteresis correction circuits 31A and 31B, the phase comparator 34, and the low-pass filter 41 shown in FIG. 10 can be reduced, so that power consumption can be reduced.
In addition, by integrating the current detection signal, highly accurate phase control can be performed while absorbing disturbance noise.

<< 2nd Embodiment >>
FIG. 5 is a configuration diagram schematically illustrating an actuator drive circuit according to the second embodiment.
The drive circuit 1A of the second embodiment is connected to a truss-type actuator 2, and drives the actuator 2 to rotate. The truss-type actuator 2 has the same configuration as the actuator 2 of the first embodiment, and operates in the same manner.

Hereinafter, the phase comparison operation of the single-phase driving principle circuit in the truss type actuator will be briefly described.
The VCO 42 outputs a drive clock having a frequency according to the applied voltage. The pulse generation circuit 43 generates a rectangular pulse based on the drive clock output from the VCO 42. The rectangular pulse is output to the A-phase circuit, the B-phase circuit, and the integration area pulse generation circuit 44.
The drive circuit 1 is roughly classified into an A-phase circuit that supplies a drive signal to the displacement element 23A, and a B-phase circuit that supplies a drive signal to the displacement element 23B.

  The A-phase circuit includes a driver 11A, an LC filter 12A, an interlock switch 13A that interlocks complementarily with the B-phase interlock switch 13B, a current detection resistor 14A, and a detector 15A. This driver 11A is configured by bridge-connecting two amplifiers. The output signal of the pulse generation circuit 43 is input to the input side of the driver 11A. The driver 11A outputs a signal obtained by amplifying the signal from a first output terminal, and outputs a signal obtained by amplifying and inverting the signal from a second output terminal.

  The first output terminal and the second output terminal of the driver 11A are connected to the LC filter 12A. An interlock switch 13A is connected to two output terminals of the LC filter 12A. When the interlock switch 13A is open, a sine wave signal is output from the output terminal of the LC filter 12A. When the interlock switch 13A is closed, no signal is output from the output terminal of the LC filter 12A.

One output terminal of the LC filter 12A is connected to one end of the displacement element 23A, and the other output terminal is connected to the other end of the displacement element 23A via the current detection resistor 14A.
The detector 15A amplifies and detects the voltage across the current detection resistor 14A in an analog manner, and thus detects the current flowing through the displacement element 23A. The output signal of the detector 15A is input to the selector 53.

  Similarly, the B-phase circuit includes a driver 11B, an LC filter 12B, an interlocking switch 13B that interlocks complementarily with the A-phase interlocking switch 13A, a current detection resistor 14B, and a detector 15B. The B-phase circuit is connected in the same manner as the A-phase circuit.

  When the A-phase circuit drives the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit does not drive the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a driving signal, and the current flowing through the displacement element 23B is a non-driving signal.

  When the A-phase circuit does not drive the displacement element 23A and detects the current flowing through the displacement element 23A, the B-phase circuit drives the displacement element 23B and detects the current flowing through the displacement element 23B. I have. In this case, the current flowing through the displacement element 23A is a non-drive-side signal, and the current flowing through the displacement element 23B is a drive-side signal.

  In the second embodiment, by generating an integration region pulse from the detection signal on the non-driving side, a voltage change due to the integration value is used for controlling the operation of the VCO 42.

The integration region pulse generation circuit 45 generates a second integration region pulse whose phase is advanced by 45 ° with respect to the drive pulse. The integration circuit 51B integrates the non-drive side detection signal using the second integration area pulse. When the integration value obtained by the second integration region pulse is 0, phase control is performed so that a target phase difference is obtained.
Hereinafter, the phase control based on the integral value will be described with reference to FIGS.

FIG. 6 is a waveform diagram showing a drive pulse generation signal and a drive-side amplifier output signal at a phase difference of 0 °, a non-drive-side amplifier output signal, and an integration region pulse when a phase difference of 45 ° is set.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive-side detection signal. This drive side detection signal is a sine wave and is an output signal of the detector 15A in FIG. The zero-cross point of the drive-side detection signal is behind the edge of the drive pulse generation signal by the phase difference Φ. The phase difference Φ is generated by the LC filter 12A.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-driving side.
Time t60 is the rising edge of the integration region pulse and is the start time of the integration. At time t60, the phase is advanced by 45 ° with respect to time t61, which is the zero cross point of the drive-side detection signal. Time t63 is the falling edge of the integration area pulse and is the end time of the integration. At time t63, the phase is delayed by 180 ° from time t60.

  In FIG. 6, the phase difference between the non-drive side detection signal and the drive side detection signal is 45 °. At time t62, which is the zero-cross point of the non-drive-side detection signal, the phase is delayed by 45 ° with respect to the zero-cross point of the drive-side detection signal, and the phase is delayed by 90 ° with respect to time t60. Therefore, the positive region and the negative region are equal in the integration region of the detection signal on the non-driving side.

FIG. 7 is a waveform diagram showing the drive pulse generation signal and the drive-side amplifier output signal in the leading phase, the non-drive-side amplifier output signal, and the integration region pulse when the phase difference is set to 45 °.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive-side detection signal. This drive side detection signal is a sine wave and is an output signal of the detector 15A in FIG. The zero-cross point of the drive-side detection signal is behind the edge of the drive pulse generation signal by the phase difference Φ. The phase difference Φ is generated by the LC filter 12A.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-driving side.
Time t70 is the rising edge of the integration region pulse and is the start time of integration. At time t70, the phase is advanced by 45 ° with respect to time t71, which is the zero cross point of the drive-side detection signal. Time t73 is the falling edge of the integration area pulse and is the end time of the integration. At time t73, the phase is delayed by 180 ° from time t70.

  In FIG. 7, the phase of the detection signal on the non-drive side is advanced by approximately 45 ° with respect to the original phase (see the third graph in FIG. 6). Time t72, which is the zero-cross point of the non-drive-side detection signal, is near the zero-cross point of the drive-side detection signal, and has a phase lag of 45 ° with respect to time t70. Therefore, in the integration region of the detection signal on the non-drive side, the positive region is larger than the negative region.

FIG. 8 is a waveform diagram showing the drive pulse generation signal and the drive-side amplifier output signal, the non-drive-side amplifier output signal, and the integration region pulse when the phase difference is set to 45 ° in the delay phase.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

  The second graph is a waveform diagram of the drive-side detection signal. This drive side detection signal is a sine wave and is an output signal of the detector 15A in FIG. The zero-cross point of the drive-side detection signal is behind the edge of the drive pulse generation signal by the phase difference Φ. The phase difference Φ is generated by the LC filter 12A.

In the third graph, a solid line indicates a detection signal on the non-driving side, and a broken line indicates an integration region pulse. The hatched area indicates the integration area of the detection signal on the non-drive side.
Time t80 is the rising edge of the integration region pulse and is the start time of integration. At time t80, the phase is advanced by 45 ° with respect to time t81, which is the zero cross point of the drive side detection signal. Time t83 is the falling edge of the integration area pulse and is the end time of the integration. At time t83, the phase is delayed by 180 ° with respect to time t80.

  In FIG. 8, the phase of the detection signal on the non-drive side is delayed by approximately 45 ° from the original phase (see the third graph in FIG. 6). At time t82, which is the zero-cross point of the non-drive-side detection signal, the phase is delayed by approximately 90 ° with respect to the zero-cross point of the drive-side detection signal, and the phase is delayed by 135 ° with respect to time t80. Therefore, in the integration region of the detection signal on the non-drive side, the positive region is larger than the negative region.

  Returning to FIG. 5, the operation of the integration area pulse generation circuit 45 will be described. The integration region pulse generation circuit 45 further generates a first integration region pulse whose phase is advanced by 90 ° with respect to the drive pulse. The integration circuit 51A integrates the drive-side detection signal using the first integration area pulse. The subtractor 52A subtracts the integral value obtained by the first integral region pulse from the integral value obtained by the second integral region pulse. The subtracter 52B subtracts the integral value obtained by the second integral region pulse from the integral value obtained by the first integral region pulse.

  In FIG. 5, since the switch 55 has been switched to the side of the subtractor 52A, the output signal of the subtractor 52A is fed back to the VCO 42. That is, when the difference between the integral value obtained by the second integration region pulse and the integral value obtained by the first integration region pulse is 0, the phase control is performed so that the target phase difference is obtained.

  When the non-drive side switches to the A phase and the drive side switches to the B phase, the switch 55 switches to the side of the subtractor 52B. At this time, the subtractor 52B subtracts the integral value obtained by the second integral region pulse from the integral value obtained by the first integral region pulse, and feeds it back to the VCO.

FIG. 9 is a waveform diagram illustrating a drive pulse generation signal, a drive-side amplifier output signal and an integration region pulse, and a phase-lagged non-drive-side amplifier output signal and an integration region pulse.
The first graph is a waveform diagram of the drive pulse generation signal. This drive pulse generation signal is a rectangular wave having a predetermined period.

In the second graph, the solid line indicates the drive-side detection signal, and the broken line indicates the first integration region pulse. The hatched area indicates an integration area of the drive-side detection signal.
This drive side detection signal is a sine wave and is an output signal of the detector 15A in FIG. The first integration region pulse is a rectangular wave, and its phase is advanced by 90 ° with respect to the edge of the drive pulse generation signal. Time t90 is the rising edge of the first integration region pulse and the start time of integration. Time t91 is a zero cross point of the drive side detection signal, and the phase is delayed by a predetermined angle with respect to the rising edge of the drive pulse generation signal. Time t92 is the falling edge of the first integration region pulse and is the end time of the integration. At time t92, the phase is delayed by 180 ° from time t90.

  In the third graph, the non-driving side detection signal under control is indicated by a sine wave solid line, the non-driving side detection signal after control is indicated by a sine wave broken line, and the second integration region pulse is indicated by a rectangular broken line. . The hatched area indicates the integration area of the detection signal on the non-driving side.

  This non-drive side detection signal is a sine wave and is an output signal of the detector 15B in FIG. The second integration region pulse of the non-drive side detection signal is a rectangular wave, and its phase is advanced by 45 ° with respect to the edge of the drive pulse generation signal. Further, the phase of the second integration region pulse is delayed by 45 ° with respect to the first integration region pulse.

  Time t93 is the rising edge of the second integration region pulse and the start time of integration. Time t94 is a zero cross point of the drive-side detection signal under control, and the phase is delayed by 90 ° from time t93. Time t95 is the falling edge of the second integration region pulse and is the end time of the integration. At time t95, the phase is delayed by 180 ° with respect to time t93.

  Comparing the integration area of the drive-side detection signal with the integration area of the non-drive-side detection signal, the integration area of the drive-side detection signal has more negative areas. The drive circuit 1A subtracts the drive-side integration region from the non-drive-side integration region by the subtractor 52A, and feeds back the result to the VCO. As a result, the non-driving side detection signal is in the state after the control indicated by the broken line. That is, the drive circuit 1A controls so that the integration area of the drive-side detection signal and the integration area of the non-drive-side detection signal match.

  When the non-drive side is switched to the A-phase and the drive side is switched to the B-phase, the subtractor 52B subtracts the drive-side integration area from the non-drive-side integration area and feeds it back to the VCO 42. This switching is performed by the switch 55.

<< Effect of Second Embodiment >>
The current detection signal is integrated using an integration area pulse phase-shifted from the drive pulse.
As a result, the number of circuits such as the hysteresis correction circuits 31A and 31B, the phase comparator 34, and the low-pass filter 41 shown in FIG. 10 can be reduced, so that power consumption can be reduced.
In addition, by integrating the current detection signal, highly accurate phase control can be performed while absorbing disturbance noise.

  Further, by integrating the drive-side detection signal and adding it to the VCO control voltage, the phase shift amount of the integration region pulse can be automatically corrected.

  In the present embodiment, the layer A is set as the driving side and the layer B is set as the non-driving side. However, the present invention is not limited to this.

  In the following, the inventions described in the claims first attached to the application form of this application are appended. The item numbers of the appended claims are as set forth in the claims originally attached to the application for this application.

(Appendix)
<< Claim 1 >>
A plurality of displacement elements for generating a predetermined displacement,
A driving member coupled to the plurality of displacement elements and driven by displacement of the plurality of displacement elements;
A driven member driven by the contact of the driving member,
An actuator drive circuit comprising:
A drive unit that applies a drive signal to one of the plurality of displacement elements, and a detection unit that detects a detection signal from the other one of the plurality of displacement elements.
A pulse generation unit that generates an integration region pulse shifted by a predetermined phase from the drive signal;
An integration unit that integrates the detection signal using the integration region pulse;
A voltage control unit that controls the frequency of the drive signal, using the output signal of the integration unit as a phase comparison output,
An actuator drive circuit comprising:
<< Claim 2 >>
The predetermined phase is +45 degrees;
The actuator drive circuit according to claim 1, wherein:
<< Claim 3 >>
The integration unit integrates the detection signal corresponding to a predetermined section of the integration area pulse,
The actuator drive circuit according to claim 1 or 2, wherein:
<< Claim 4 >>
The voltage control unit, if the value obtained by integrating the detection signal into the integration unit is a positive value, controls to advance the phase of the frequency of the drive signal,
The actuator drive circuit according to claim 1 or 2, wherein:
<< Claim 5 >>
The voltage control unit, when the value obtained by integrating the detection signal into the integration unit is a negative value, controls to delay the phase of the frequency of the drive signal,
The actuator drive circuit according to claim 1 or 2, wherein:
<< Claim 6 >>
A plurality of displacement elements for generating a predetermined displacement,
A driving member coupled to the plurality of displacement elements and driven by displacement of the plurality of displacement elements;
A driven member driven by the contact of the driving member,
An actuator drive circuit comprising:
A drive unit that applies a drive signal to one of the plurality of displacement elements, and a detection unit that detects a detection signal from the other one of the plurality of displacement elements.
A pulse generation unit that generates a first integration region pulse shifted by a first phase and a second integration region pulse shifted by a second phase from the drive signal;
A first integration unit that integrates the drive signal using the first integration region pulse;
A second integration unit that integrates the detection signal using the second integration area pulse;
A voltage control unit that controls a frequency of the drive signal by using a difference between an output signal of the first integration unit and an output signal of the second integration unit as a phase comparison output;
An actuator drive circuit comprising:
<< Claim 7 >>
The first phase is -90 degrees,
The second phase is -45 degrees;
7. The actuator drive circuit according to claim 6, wherein:
<< Claim 8 >>
An actuator drive circuit according to any one of claims 1 to 7,
Electronic equipment characterized by the above-mentioned.

1, 1A, 1B drive circuit 11A, 11B driver (part of drive unit)
12A, 12B LC filter (part of drive unit)
13A, 13B Interlocking switches 14A, 14B Current detection resistor (part of detection unit)
15A, 15B detector (part of the detector)
16A, 16B Detector 2 Actuator 21 Pressurizing section 22 Fixed section 23A, 23B Displacement element 24 Synthesizing section (driving member)
25 Rotor (driven member)
31A, 31B Hysteresis correction circuit 32 Selector 33 Phase difference setting circuit 34 Phase comparator 41 Low pass filter 42 VCO
43 pulse generation circuit 44, 45 integration area pulse generation circuit (pulse generation unit)
51A, 51B, 54 Integrator (integrator)
52 Subtractor 53 Selector

Claims (8)

A plurality of displacement elements for generating a predetermined displacement,
A driving member coupled to the plurality of displacement elements and driven by displacement of the plurality of displacement elements;
A driven member driven by the contact of the driving member,
An actuator drive circuit comprising:
A drive unit that applies a drive signal to one of the plurality of displacement elements, and a detection unit that detects a detection signal from the other one of the plurality of displacement elements.
A pulse generation unit that generates an integration region pulse shifted by a predetermined phase from the drive signal;
An integration unit that integrates the detection signal using the integration region pulse;
A voltage control unit that controls the frequency of the drive signal, using the output signal of the integration unit as a phase comparison output,
An actuator drive circuit comprising: The predetermined phase is +45 degrees;
The actuator drive circuit according to claim 1, wherein: The integration unit integrates the detection signal corresponding to a predetermined section of the integration area pulse,
The actuator drive circuit according to claim 1 or 2, wherein: The voltage control unit, when the value obtained by integrating the detection signal into the integration unit is a positive value, controls to advance the phase of the frequency of the drive signal,
The actuator drive circuit according to claim 1 or 2, wherein: The voltage control unit, when the value obtained by integrating the detection signal into the integration unit is a negative value, controls to delay the phase of the frequency of the drive signal,
The actuator drive circuit according to claim 1 or 2, wherein: A plurality of displacement elements for generating a predetermined displacement,
A driving member coupled to the plurality of displacement elements and driven by displacement of the plurality of displacement elements;
A driven member driven by the contact of the driving member,
An actuator drive circuit comprising:
A drive unit that applies a drive signal to one of the plurality of displacement elements, and a detection unit that detects a detection signal from the other one of the plurality of displacement elements.
A pulse generator configured to generate a first integration region pulse shifted by a first phase and a second integration region pulse shifted by a second phase from the driving signal;
A first integration unit that integrates the drive signal using the first integration region pulse;
A second integration unit that integrates the detection signal using the second integration area pulse;
A voltage control unit that controls a frequency of the drive signal by using a difference between an output signal of the first integration unit and an output signal of the second integration unit as a phase comparison output;
An actuator drive circuit comprising: The first phase is -90 degrees,
The second phase is -45 degrees;
7. The actuator drive circuit according to claim 6, wherein: An actuator drive circuit according to any one of claims 1 to 7,
Electronic equipment characterized by the above-mentioned.

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