Control device and method for controlling a piezoelectric drive device using phase difference

Patent metadata

Field	Value
Publication number	US-11411512-B2
Application number	US-201816145331-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 29, 2017
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

A control device of a piezoelectric drive device includes a drive pulse signal generation unit that generates a binary drive pulse signal, a drive signal generation unit that generates a drive signal which is applied to the piezoelectric element for drive from the drive pulse signal, a detection pulse signal generation unit that generates a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection, and a phase difference acquisition unit that acquires a phase difference between the drive pulse signal and the detection pulse signal, based on a rising edge and a falling edge of the drive pulse signal and a rising edge and a falling edge of the detection pulse signal.

First claim

What is claimed is:

1. A control device of a piezoelectric drive device including a vibration body that includes a piezoelectric element for drive and a piezoelectric element for detection, vibrates according to drive of the piezoelectric element for drive, and outputs a detection signal according to the vibration from the piezoelectric element for detection, the control device comprising:
a drive pulse signal generation unit that generates a binary drive pulse signal;
a drive signal generation unit that generates a drive signal which is applied to the piezoelectric element for drive from the binary drive pulse signal;
a detection pulse signal generation unit that generates a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection; and
a phase difference acquisition unit that acquires a phase difference between the binary drive pulse signal and the detection pulse signal, based on a rising edge and a falling edge of the binary drive pulse signal and a rising edge and a falling edge of the detection pulse signal.

2. The control device of a piezoelectric drive device according to claim 1 ,
wherein the phase difference acquisition unit acquires the phase difference, based on a center of the rising and falling edges of the binary drive pulse signal and a center of the rising and falling edges of the detection pulse signal.

3. The control device of a piezoelectric drive device according to claim 1 , further comprising:
a drive control unit that controls drive of the drive pulse signal generation unit, based on the phase difference which is acquired by the phase difference acquisition unit.

4. A control device of a piezoelectric drive device including a vibration body that includes a piezoelectric element for drive and a piezoelectric element for detection, vibrates according to drive of the piezoelectric element for drive, and outputs a detection signal according to the vibration from the piezoelectric element for detection, the control device comprising:
a drive pulse signal generation unit that generates a binary drive pulse signal;
a drive signal generation unit that generates a drive signal which is applied to the piezoelectric element for drive from the binary drive pulse signal; a detection pulse signal generation unit that generates a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection; and
a phase difference acquisition unit that acquires a phase difference between the binary drive pulse signal and the detection pulse signal, based on a duty of the binary drive pulse signal, a rising edge or a falling edge of the binary drive pulse signal, and a rising edge or a falling edge of the detection pulse signal.

5. The control device of a piezoelectric drive device according to claim 4 ,
wherein the phase difference acquisition unit acquires the phase difference, based on a center of the rising and falling edges of the binary drive pulse signal that is predicted based on the duty of the binary drive pulse signal and the rising edge or the falling edge of the binary drive pulse signal, and a center of the rising and falling edges of the detection pulse signal that is predicted based on the rising edge or the falling edge of the detection pulse signal.

6. The control device of a piezoelectric drive device according to claim 4 , further comprising:
a drive control unit that controls drive of the drive pulse signal generation unit, based on the phase difference which is acquired by the phase difference acquisition unit.

7. The control method of a piezoelectric drive device according to claim 6 ,
wherein the phase difference is acquired based on a center of the rising and falling edges of the binary drive pulse signal and a center of the rising and falling edges of the detection pulse signal.

8. A control device of a piezoelectric drive device including a vibration body that includes a piezoelectric element for drive and a piezoelectric element for detection, vibrates according to drive of the piezoelectric element for drive, and outputs a detection signal according to the vibration from the piezoelectric element for detection, the control device comprising:
a drive pulse signal generation unit that generates a binary drive pulse signal;
a drive signal generation unit that generates a drive signal which is applied to the piezoelectric element for drive from the binary drive pulse signal;
a monitor pulse signal generation unit that generates a monitor pulse signal by binarizing the drive signal;
a detection pulse signal generation unit that generates a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection; and
a phase difference acquisition unit that acquires a phase difference between the binary drive pulse signal and the detection pulse signal, based on a rising edge and a falling edge of the monitor pulse signal and a rising edge and a falling edge of the detection pulse signal.

9. The control device of a piezoelectric drive device according to claim 8 , further comprising:
a drive control unit that controls drive of the drive pulse signal generation unit, based on the phase difference which is acquired by the phase difference acquisition unit.

10. A control method of a piezoelectric drive device including a vibration body that includes a piezoelectric element for drive and a piezoelectric element for detection, vibrates according to drive of the piezoelectric element for drive, and outputs a detection signal according to the vibration from the piezoelectric element for detection, the control method comprising:
generating a binary drive pulse signal;
generating a drive signal which is applied to the piezoelectric element for drive from the binary drive pulse signal;
generating a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection; and
acquiring a phase difference between the binary drive pulse signal and the detection pulse signal, based on a rising edge and a falling edge of the binary drive pulse signal and a rising edge and a falling edge of the detection pulse signal.

11. The control method of a piezoelectric drive device according to claim 10 ,
wherein the phase difference is acquired based on a center of the rising and falling edges of the binary drive pulse signal that is predicted based on the duty of the binary drive pulse signal and the rising edge or the falling edge of the binary drive pulse signal, and a center of the rising and falling edges of the detection pulse signal that is predicted based on the rising edge or the falling edge of the detection pulse signal.

12. The control method of a piezoelectric drive device according to claim 10 ,
wherein the binary drive pulse signal is generated based on the phase difference.

13. A control method of a piezoelectric drive device including a vibration body that includes a piezoelectric element for drive and a piezoelectric element for detection, vibrates according to drive of the piezoelectric element for drive, and outputs a detection signal according to the vibration from the piezoelectric element for detection, the control method comprising:
generating a binary drive pulse signal;
generating a drive signal which is applied to the piezoelectric element for drive from the binary drive pulse signal;
generating a detection pulse signal by binarizing the detection signal which is output from the piezoelectric element for detection; and
acquiring a phase difference between the binary drive pulse signal and the detection p

Assignees

• Seiko Epson Corp

Inventors

• Kajino Kiichi

Classifications

• H10P72/3202

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• H02N2/103 Primary

  by pressing one or more vibrators against the rotor · CPC title

• H02N2/147 Primary

  Multi-phase circuits · CPC title

• G03B21/2066

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title

• H02N2/142

  Small signal circuits; Means for controlling position or derived quantities, e.g. speed, torque, starting, stopping, reversing · CPC title