Piezoelectric element driving apparatus and method, and piezoelectric system using the same

Patent metadata

Field	Value
Publication number	US-9680084-B2
Application number	US-201414246842-A
Country	US
Kind code	B2
Filing date	Apr 7, 2014
Priority date	Dec 30, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A piezoelectric element driving apparatus may apply a predetermined driving signal to a piezoelectric element to drive the piezoelectric element. The driving signal may be an asymmetrical waveform in which amplitudes of first and second polarities thereof are different from each other. An exemplary embodiment in the present disclosure may provide a piezoelectric element driving apparatus and method having a high output while protecting dielectric characteristics of a piezoelectric element by driving the piezoelectric element using an asymmetrical driving signal.

First claim

What is claimed is:

1. A piezoelectric element driving apparatus applying a predetermined driving signal to a piezoelectric element to drive the piezoelectric element, comprising:
a waveform synthesizing unit outputting first and second digital signals for generating a driving signal;
a digital-to-analog converting unit outputting first and second analog signals corresponding to the first and second digital signals, respectively; and
an amplifying unit amplifying the first and second analog signals and providing the amplified first and second analog signals to a piezoelectric element,
wherein the waveform synthesizing unit generates the first and second digital signals using a plurality of digital values included in a preset lookup table, and
wherein the driving signal is an asymmetrical waveform in which amplitudes of first and second polarities thereof are different from each other.

2. The piezoelectric element driving apparatus of claim 1 , wherein the driving signal has positive and negative polarities as the first and second polarities, respectively, and is a waveform in which the amplitude of the first polarity thereof is larger than that of the second polarity thereof.

3. The piezoelectric element driving apparatus of claim 1 , wherein the driving signal is a waveform in which maximum amplitudes of the first and second polarities thereof are different from each other.

4. The piezoelectric element driving apparatus of claim 1 , wherein at least half of a period of the driving signal is a sine wave.

5. The piezoelectric element driving apparatus of claim 1 , wherein the piezoelectric element is formed by stacking a plurality of piezoelectric layers.

6. The piezoelectric element driving apparatus of claim 1 , wherein the piezoelectric element is formed by stacking eight to twenty four piezoelectric layers, each of which has a thickness of 15 or more to 100 μm or less.

7. The piezoelectric element driving apparatus of claim 1 , wherein the piezoelectric element is formed by stacking twelve piezoelectric layers, and the amplitude of the positive polarity of the driving signal is smaller than 35V and the amplitude of the negative polarity thereof is larger than −25V.

8. The piezoelectric element driving apparatus of claim 1 , wherein the piezoelectric element is formed by stacking twenty four piezoelectric layers, and the amplitude of the positive polarity of the driving signal is smaller than 18V and the amplitude of the negative polarity thereof is larger than −12V.

9. The piezoelectric element driving apparatus of claim 6 , wherein the driving signal has positive and negative polarities as the first and second polarities, respectively, and the amplitude of the second polarity of the driving signal is larger than −25V.

10. The piezoelectric element driving apparatus of claim 6 , wherein the driving signal has positive and negative polarities as the first and second polarities, respectively, and the amplitude of the first polarity of the driving signal is larger than 35V.

11. A piezoelectric element driving apparatus generating a pair of waveforms and applying the pair of waveforms to both terminals of a piezoelectric element, respectively, comprising:
a waveform synthesizing unit outputting first and second digital signals for generating a driving signal;
a digital-to-analog converting unit outputting first and second analog signals corresponding to the first and second digital signals, respectively; and
an amplifying unit amplifying the first and second analog signals and providing the amplified first and second analog signals to a piezoelectric element,
wherein the waveform synthesizing unit generates the first and second digital signals using a plurality of digital values included in a preset lookup table, and
wherein the pair of waveforms include:
a first symmetrical waveform of which amplitudes of first and second polarities are the same as each other; and
a second asymmetrical waveform of which amplitudes of first and second polarities are different from each other.

12. The piezoelectric element driving apparatus of claim 11 , wherein the second asymmetrical waveform has a phase difference of 180 degrees or less from the first symmetrical waveform.

13. The piezoelectric element driving apparatus of claim 11 , wherein it applies the first symmetrical waveform to a positive terminal of the piezoelectric element and applies the second asymmetrical waveform to a negative terminal of the piezoelectric element.

14. The piezoelectric element driving apparatus of claim 13 , wherein the second asymmetrical waveform has positive and negative polarities as the first and second polarities, respectively, and the amplitude of the first polarity of the second waveform is smaller than that of the second polarity thereof.

15. A piezoelectric element driving apparatus generating a pair of sine waves and applying the pair of sine waves to both terminals of a piezoelectric element, respectively, comprising:
a waveform synthesizing unit outputting first and second digital signals for generating a driving signal;
a digital-to-analog converting unit outputting first and second analog signals corresponding to the first and second digital signals, respectively;
an amplifying unit amplifying the first and second analog signals and providing the amplified first and second analog signals to a piezoelectric element,
wherein the waveform synthesizing unit generates the first and second digital signals using a plurality of digital values included in a preset lookup table, and
wherein the pair of sine waves include:
a first asymmetrical sine wave of which amplitudes of first and second polarities are different from each other; and
a second asymmetrical sine wave of which amplitudes of first and second polarities are different from each other.

16. The piezoelectric element driving apparatus of claim 15 , wherein the second asymmetrical sine wave has a phase difference of 180 degrees or less from the first asymmetrical sine wave.

17. The piezoelectric element driving apparatus of claim 15 , wherein it applies the first asymmetrical sine wave to a positive terminal of the piezoelectric element and applies the second asymmetrical sine wave to a negative terminal of the piezoelectric element.

18. The piezoelectric element driving apparatus of claim 15 , wherein the first asymmetrical sine wave has positive and negative polarities as the first and second polarities, respectively, and the amplitude of the first polarity of the first asymmetrical sine wave is larger than that of the second polarity thereof.

19. The piezoelectric element driving apparatus of claim 15 , wherein the second asymmetrical sine wave has positive and negative polarities as the first and second polarities, respectively, and the amplitude of the first polarity of the second asymmetrical sine wave is smaller than that of the second polarity thereof.

20. A piezoelectric element driving apparatus comprising:
a waveform synthesizing unit outputting first and second digital signals for generating a driving signal;
a digital-to-analog converting unit outputting first and second analog signals corresponding to the first and second digital signals, respectively; and
an amplifying unit amplifying the first and second analog signals and providing the amplified first and second analog signals to a piezoelectric element,
wherein the waveform synthesizing unit generates the first and second digital signals using a plurality of digital values included in a preset lookup

Assignees

• Samsung Electro Mech
• Mplus Co Ltd

Inventors

• Ko Joo Yul
• Seo Jung Wook
• Yoon Ho Kwon
• Cho Hong Yeon
• Kim Boum Seock
• Hur Kang Heon

Classifications

• B06B2201/55

  Piezoelectric transducer · CPC title

• H02N2/14

  Drive circuits; Control arrangements {or methods} · CPC title

• H01L41/083 Primary

  Electricity · mapped topic

• H01L41/042

  Electricity · mapped topic

• H02N2/06 Primary

  Drive circuits; Control arrangements {or methods} · CPC title