WO2006126401A1 - Oscillation controller for piezoelectric resonant sensor element - Google Patents

Oscillation controller for piezoelectric resonant sensor element Download PDF

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Publication number
WO2006126401A1
WO2006126401A1 PCT/JP2006/309494 JP2006309494W WO2006126401A1 WO 2006126401 A1 WO2006126401 A1 WO 2006126401A1 JP 2006309494 W JP2006309494 W JP 2006309494W WO 2006126401 A1 WO2006126401 A1 WO 2006126401A1
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WIPO (PCT)
Prior art keywords
vibration control
sensor element
piezoelectric
electrodes
vibration
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PCT/JP2006/309494
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French (fr)
Japanese (ja)
Inventor
Kaoru Yamashita
Masanori Okuyama
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Osaka University
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Priority to JP2005152751 priority Critical
Priority to JP2005-152751 priority
Application filed by Osaka University filed Critical Osaka University
Publication of WO2006126401A1 publication Critical patent/WO2006126401A1/en

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Classifications

    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02Details
    • H03H9/125Driving means, e.g. electrodes, coils
    • H03H9/13Driving means, e.g. electrodes, coils for networks consisting of piezo-electric or electrostrictive materials
    • H03H9/132Driving means, e.g. electrodes, coils for networks consisting of piezo-electric or electrostrictive materials characterized by a particular shape
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03HIMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15Constructional features of resonators consisting of piezo-electric or electrostrictive material
    • H03H9/17Constructional features of resonators consisting of piezo-electric or electrostrictive material having a single resonator
    • H03H9/171Constructional features of resonators consisting of piezo-electric or electrostrictive material having a single resonator implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type
    • H03H9/172Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume
    • H03H9/174Membranes
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00Piezo-electric transducers; Electrostrictive transducers

Abstract

A piezoelectric resonant ultrasonic sensor element (20) is provided with an oscillation controlling outer electrode (19) formed in the vicinity of the periphery of an inner electrode (18) in addition to two inner electrode (18) and common electrode (16) pairs. (A pair is formed by the outer electrode (19) and the common electrode (16).) A detection signal detected by the pair of electrodes (16, 18) and outputted through a terminal (T1) is amplified by a variable gain amplifier (31) by a prescribed gain controlled and set by a gain controller (30), and a reverse phase oscillation control signal is applied to the oscillation controlling outer electrode (19) through a terminal (T2), and oscillation of the detection signal, which is obtained when an ultrasonic wave, i.e. an oscillation wave, is detected, is controlled to be attenuated.

Description

Specification

Vibration control apparatus of the piezoelectric resonant sensor element

Technical field

[0001] The present invention is, for example, an ultrasonic sensor element, relates to a vibration control device and a vibration control method of a piezoelectric resonant sensor element, such as a sonic sensor element or vibration sensor element.

BACKGROUND

[0002] In recent years, a vehicle control, in terms of distance measurement and disability subsidies application, three-dimensional imaging (imaging) techniques using ultrasonic waves have attracted considerable attention. In particular, the piezoelectric resonant ultrasonic sensor element on a silicon diaphragm, there is an advantage that the manufacturing process is easily integrated into simple semiconductor devices (e.g., Non-Patent Document 1 see.).

[0003] The present inventors have used a piezoelectric PZT ceramic thin film on a silicon diaphragm, and invented a piezoelectric ultrasonic micro sensor element sensitive (e.g., Non-Patent Document 2 see;.) . Early sensors manufacturing process, the polarization change at the central portion because it has always opposite direction from that of the peripheral portion of the Daiafura arm to vibrate, the upper electrode was formed only in the center portion of the diaphragm (e.g., non-patent documents 3 and 4.) 0

[0004] In the piezoelectric resonant ultrasonic sensor element of the above prior art, the sensitivity was relatively low bears, there is a problem that is susceptible to external noise in the output voltage. In order to solve the above problems, the present inventors have compared to the prior art to increase the sensitivity, difficulty under the influence of either One external noise !, piezoelectric resonance ultrasonic sensor element (hereinafter, conventional and examples cormorants.) was invented (e.g., see Patent Document 1.) o the piezoelectric resonant ultrasonic sensor element according to the prior art is characterized by being configured as follows. Strength becomes by clamping set the dielectric at least a pair of electrodes, having a predetermined resonant frequency in the piezoelectric ultrasonic sensor element comprising Te a piezoelectric sensor for detecting the ultrasonic wave, on one side of the ferroelectric a common electrode provided, the strength and inner electrode provided at a substantially central portion of the dielectric other was on the side with ferroelectrics, provided outside the inner electrode comprising at other side of the ferroelectric Ete configured Bei an outer electrode. Here, detecting the output voltage between the inner electrode and the outer electrode when detecting an ultrasonic wave. Further, when detecting an ultrasonic wave, and the sign of our Keru output voltage to the inner electrode to the common electrode, providing an outer electrode to the code and the different location of such output voltage in the outer electrode to the common electrode.

[0005] Patent Document 1: JP 2005- 039720 JP.

Hitokuhi literature 1:.. T. Faoula et al, Analytical and unite element modeling of resonant s ilicon microsensors ", Sensors and Materials, Vol 9, No. 8, pp.501- 519, 1997.

Patent Document 2:. K. Yamashita et al, "Arrayed ultrasonic microsensors with high direc tivity for in-air use using PZT thin film on silicon diaphragms, Sensors and Actuator s A, Vol.97- 98., pp.302- 307 , 2002.

Non-Patent Document 3:. K. Yamashita et al, "Ultrasonic Array Sensor Using Piezoelectric Fil m on Silicon Diaphragm and Its Resonant-Frequency Tuning, Transducer '03, Vol.1, No.5, pp.939- 942, 2003.

Patent Document 4:. JT Bernstein et al, "Micromachined High Frequency Ferroelectric Sonar Transducers, IEEE Transactions on Ultrasonic Ferroelectric Frequency Cou nter, Vol.44, pp.960- 969, 1996.

Disclosure of the Invention

Problems that the Invention is to you'll solve

[0006] When using the vibration type sensor element such as an ultrasonic sensor device, the resonance characteristics become problems. More mechanical quality factor of the resonant (Q value) is high, can configure devices relative sensitivity can be obtained large output is higher with less input energy, when performing distance measurement by an ultrasonic sensor element is , Ri Do in pulling the slow long tails damping and vibration Q value is high, there is a problem that lowering the distance resolution. In the prior art, to lower the Q value as the distance resolution required is obtained, low, to constitute a device device settle for sensitivity it was.

An object of the present invention is to solve the above problems, to provide a vibration control device and a vibration control method of a piezoelectric resonant sensor element capable of damping the Nag vibration can decrease the Q value effectively It is in.

Means for Solving the Problems

[0008] vibration control apparatus of the piezoelectric resonant sensor element according to the first invention comprises by clamping set at least one pair of electrodes of the piezoelectric detection by detecting a vibration wave having a predetermined resonant frequency in the vibration control apparatus of the piezoelectric resonant sensor element for outputting a signal,

The piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal

Further comprising a vibration control electrode formed in the vicinity of the electrodes,

By applying a vibration control signal of opposite phase to the vibration control electrodes by amplifying the detection signal by a predetermined gain, the amplifier means for controlling so as to damp vibration of the detection signal when it detects a vibration wave characterized by comprising a.

[0009] In the vibration control apparatus of the piezoelectric resonant sensor element, and further comprising a control means for setting the gain of said amplifying means. Further, the pair of electrodes is preferably formed in a central portion of the piezoelectric body and having a circular, substantially circular, substantially elliptical or substantially square.

[0010] vibration control apparatus of the piezoelectric resonant sensor element according to the second invention comprises by clamping set at least one pair of electrodes of the piezoelectric detection by detecting a vibration wave having a predetermined resonant frequency in the vibration control apparatus of the piezoelectric resonant sensor element for outputting a signal,

The piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal

Further comprising a vibration control electrode formed in the vicinity of the electrodes,

In response to the detection signal, after a delay of rise time forces a predetermined time of the detection signal, the predetermined vibration control signal by applying to the vibration control electrode, the detection signal when it detects a vibration wave characterized by comprising control means for controlling so as to damp vibrations.

[0011] In the vibration control apparatus of the piezoelectric resonant sensor element, the control means, when the level of the detection signal exceeds a predetermined threshold, substantially half period 乃 optimum speed of the vibration wave after delaying period, the predetermined vibration control pulse signal, characterized in that indicia addition to the vibration control electrode. Further, the pair of electrodes is preferably formed in a central portion of the piezoelectric body and having a circular, substantially circular, substantially elliptical or substantially square.

[0012] vibration control method of a piezoelectric resonant sensor element of the third invention comprises by clamping set at least one pair of electrodes of the piezoelectric detection by detecting a vibration wave having a predetermined resonant frequency signal contact!, Te in vibration control method of a piezoelectric resonant sensor element for outputting, the piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal

Further comprising a vibration control electrode formed in the vicinity of the electrodes,

By applying a vibration control signal of opposite phase to the vibration control electrodes by amplifying the detection signal by a predetermined gain, the step of controlling so as to damp vibration of the detection signal when it detects a vibration wave characterized in that it contains.

[0013] In the vibration control method of the piezoelectric resonant sensor element, and further comprising a Sutetsu flop for setting the gain. Further, the pair of electrodes is preferably formed in a central portion of the piezoelectric body and a circular shape, a substantially circular shape, that having a substantially elliptical shape or a substantially square shape.

[0014] vibration control method of a piezoelectric resonant sensor element according to the fourth invention comprises by clamping set at least one pair of electrodes of the piezoelectric detection by detecting a vibration wave having a predetermined resonant frequency Contact the vibration control method of a piezoelectric resonant sensor element for outputting a signal!, Te,

The piezoelectric resonant sensor element, the above pair of electrodes for outputting the detection signal separately, further comprising a vibration control electrode formed in the vicinity of the electrodes,

In response to the detection signal, after a delay of rise time forces a predetermined time of the detection signal, the predetermined vibration control signal by applying to the vibration control electrode, the detection signal when it detects a vibration wave characterized in that it comprises a control step of controlling so as to damp vibrations.

[0015] In the vibration control method of the piezoelectric resonant sensor element, the control step, when the level of the detection signal exceeds a predetermined threshold, only substantially half period or several periods of the vibration wave after delaying the predetermined vibration control pulse signal and applying to the vibration control electrode. Further, the pair of electrodes is preferably formed in a central portion of the piezoelectric body and having a circular, substantially circular, substantially elliptical or substantially square. Effect of the invention

[0016] Therefore, according to the vibration control device and vibration control method of a piezoelectric resonant sensor element according to the first and third invention, a vibration control signal of opposite phase to amplify the detection signal by a predetermined gain by applying to the vibration control electrode, and controls so as to damp vibration of the detection signal when detecting a vibration wave can be performed damping of vibrations Nag that lowering the Q value effectively. Therefore, it constitutes a piezoelectric resonant sensor element as a good device with high sensitivity and damping property. In the prior art, the sensitivity in the distance resolution Preferences ultrasonic distance measurement has been sacrificed, high sensitivity and high distance resolution is compatible with the present invention. In the phased array for performing an angle measurement using the phase difference by using a plurality of piezoelectric resonant sensor element, the sensor oscillations long lasting it is required that its resonant frequency matches exactly, the present invention It is relaxed restrictions on by Ri resonance frequency to suppress oscillation in a short time using a simplification of the manufacturing process, unnecessary trimming 'the frequency adjustment after the production, a decrease of products defective rate, the manufacturing cost of the total the lowering Rukoto leaves in.

[0017] Further, according to the vibration control device and a vibration control method of a piezoelectric resonant sensor element according to the second and fourth aspects of the present invention, in response to the detection signal, a constant time Tokoro at the rising edge of the detection signal after delaying the predetermined vibration control signal by applying to the vibration control electrode, and controls so as to damp vibration of the detection signal when detecting a vibration wave, the vibration Nag that lowering the Q value it is possible to perform damping effectively. Therefore, it constitutes a piezoelectric resonant sensor element high sensitivity and vibration damping properties Yo, as a device. In the conventional technology, sensitivity distance resolution priority in ultrasonic distance measurement has been sacrificed, high sensitivity and high distance resolution is compatible with the present invention. Further, per cent Te, the phased array for performing an angle measurement using the phase difference by using a plurality of piezoelectric resonant sensor element, it is required that its resonant frequency matches exactly the sensor vibration is long lasting but limitation to the resonance frequency by suppressing a short time vibration using the present invention is reduced, simplification of the manufacturing process, unnecessary trimming 'the frequency adjustment after the production, a decrease of products failure rate, as a total it can reduce the cost of production.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a block diagram showing a structure of a vibration control apparatus for a piezoelectric resonant ultrasonic sensor element 20 which is a first embodiment according to the present invention.

It is a block diagram showing a structure of a vibration control device of FIG. 2 piezoelectric resonant ultrasonic sensor element 20 is a second embodiment according to the present invention.

[Figure 3] a plan view showing the structure of Figure 1 and 圆 4] piezoelectric resonant ultrasonic sensor element 20 of FIG. 1 and FIG. 2 is a vertical sectional view showing the structure of a piezoelectric resonant ultrasonic sensor element 20 of FIG. 2 it is. In 圆 5] FIG. 1 and the piezoelectric resonant ultrasonic sensor element 20 of FIG. 2, the signal waveform of the input ultrasonic signal when no vibration control (a), oar seen amount Daiafuramu and (b), the sensor output signal ( c) a diagram of signal waveforms showing.

In 圆 6] piezoelectric resonant ultrasonic sensor element 20 of FIG. 1 and FIG. 2, an input ultrasonic signal of the signal waveform (a) when the vibration control by the vibration control equipment of FIG. 1, oar seen of Daiafuramu ( and b), is a signal waveform diagram showing a sensor output signal (c).

In 圆 7] FIG. 1 and the piezoelectric resonant ultrasonic sensor element 20 of FIG. 2, an input ultrasonic signal of the signal waveform (a) when the vibration control by the vibration control equipment in Figure 2, oar seen of Daiafuramu ( and b), is a signal waveform diagram showing a sensor output signal (c).

圆 8] A diagram for explaining the optimum placement of the electrodes of the piezoelectric resonant ultrasonic sensor element 20 according to this embodiment is a three-dimensional Dara off showing the distribution of vibration amplitude and the in-plane distortion of Daiafuramu.

9 is a diagram illustrating the scale is the degree of in-plane strain in grayscale using a graph showing the distribution of the in-plane strain in FIGS. 8 and 10 to 14.

圆 10 is a plan view for explaining an arrangement of the detection electrodes and the oscillation control electrode in the piezoelectric resonant ultrasonic sensor element 20 according to this embodiment.

11 is a plan view showing the shape of a substantially circular detecting electrodes indicating the optimal arrangement and the in-plane distortion distribution when the parasitic capacitance is relatively small in FIG. 10.

圆 12 is a plan view showing the shape of a circular sensing electrodes indicating the proper placement 及 beauty plane distortion distribution equivalent to optimal arrangement when the parasitic capacitance is relatively small in FIG. 10.

13 is a plan view showing the shape of a substantially rectangular detection electrodes indicating the optimal arrangement and the in-plane distortion distribution when the parasitic capacitance is relatively large in Fig.

圆 14 is a plan view showing the shape of a substantially rectangular detection electrodes indicating the proper placement 及 beauty plane distortion distribution equivalent to optimal arrangement when the parasitic capacitance is relatively large in Fig.

A piezoelectric resonance ultrasonic sensor element 20 according to FIG. 15 embodiment, a diagram for explaining the differences between the piezoelectric resonant ultrasonic sensor element disclosed in Patent Document 1, a piezoelectric resonator it is a schematic plan view of the mold ultrasonic sensor element 20.

Is a longitudinal sectional view taken A- A 'line in FIG. 16 FIG. 15.

And [17] a piezoelectric resonant ultrasonic sensor element 20 according to the present embodiment, a diagram for explaining the differences between the piezoelectric resonant ultrasonic sensor element disclosed in Patent Document 1, a piezoelectric resonator it is a schematic plan view of a modification of the type ultrasonic sensor element 20.

18 is a B- B, longitudinal sectional view taken along the line of FIG. 17.

DESCRIPTION OF SYMBOLS

lO- ·· semiconductor wafer chip,

ll - a semiconductor substrate,

12, 13, 15, ... insulating layer,

14, the semiconductor active layer,

16 - ... the common electrode,

16a, 16b ... counter electrode,

17 · •• PZT ceramic thin film layer,

18 - ... the inner electrode,

19 - "the outer electrode,

21, 22, 25, 25a, 25b ... connecting conductors,

30 - ... gain controller,

31, a variable gain amplifier,

35 - "comparator,

36 - ... the variable DC voltage source,

40 - "one-shot oscillator,

41, ... delay circuit,

42 - ... the variable DC voltage source,

43 - "switch,

T1, Tla, T2, T2a, T3, Ti l ... terminal.

BEST MODE FOR CARRYING OUT THE INVENTION

It will be described below with reference to the accompanying drawings embodiments of the present invention. Note that the following embodiments Nio Te, similar components Nitsu are denoted by the same reference numerals Te, Ru.

[0021] the first embodiment.

Figure 1 is a block diagram showing a structure of a vibration control apparatus for a piezoelectric resonant ultrasonic sensor element 20 which is a first embodiment according to the present invention, FIG. 3 is a piezoelectric resonant ultrasonic FIGS is a longitudinal sectional view showing the structure of the sensor element 20, FIG. 4 is a plan view showing a structure of a piezoelectric resonant ultrasonic sound wave sensor element 20 of FIGS.

[0022] In the piezoelectric resonant ultrasonic sensor element 20 according to the first embodiment, the inner electrode 18 and the common electrode 16 of the two pairs of outputs the detection signal from the ultrasonic sensor element 20 separately from the inner (where a pair between the outer electrodes 19 and the common electrode 16 on the ground side) vibration control for the outer electrode 19 formed near the periphery of the electrode 8 further comprising a are detected by the pair of electrodes 16, 18 a detection signal which is output through the terminal T1, the variable gain amplifier 31, the vibration control signals of opposite phase are amplified by a predetermined gain set is controlled by the gain controller port over La 30 through the pin T2 by applying the vibration control for the outer electrode 19 Te is characterized by controlling so as to damp vibration of the detection signal when it detects the ultrasonic which is a vibration wave.

[0023] The piezoelectric resonance ultrasonic sensor element 20 according to this embodiment, as shown in FIG. 2, a PZT ceramic thin film layer 17 is a ferroelectric, the inner electrode 18 and the common electrode 16 of the one-to-one it was sandwiched set, and an outer electrode 19 and the common electrode 16 of the pair, with a predetermined resonance frequency is constituted by a piezoelectric resonant sensor element for detecting the ultrasonic sound waves. Further, as shown in FIG. 4, a substantially central portion of the upper surface of the PZ T ceramic thin layer 17, the inner electrode 18 of rectangular shape of length L

a

It is formed so as to surround the inner electrode 18 spaced apart from the inner electrode 18 on its outer periphery, the entire shape the outer electrode 19 of width L which is substantially rectangular is formed. The inner electrode 18

b

It is connected to the terminal T1 via the connecting conductor 21, the outer electrode 19 is connected to the terminal T2 via a connection conductor 22.

[0024] Here, the inner electrode 18 and outer electrode 19, for example, when the ultrasonic waves have been detected, the sign of the output voltage at the inner electrode 18 to the common electrodes 16, the output of the outer electrode 19 with respect to the common electrode 16 a position where the sign of the voltage becomes equal to each other (Note that, Yogu case be different such positions to each other, sets the oscillation control signal to the detection signal in phase;.), to form the outer electrode 19 . More preferably, upon detection of the ultrasonic wave, the absolute value output voltage at the inner electrode 18 to the common electrode 16 in the first code (e.g., positive) is substantially a maximum value, the outer electrode 19 with respect to the common electrode 16 output voltage is in a position such that its absolute value is substantially maximum at different second code (e.g., negative) and the upper Symbol first code, to form the outer electrode 19 in. More Day, Te is these codes and a method of designing a formation position location of the outer electrode 19, disclosed in Patent Document 1, Ru.

[0025] First, used in this embodiment will be described below about the structure and manufacturing method of the ultrasonic sensor element 20. The lamellar structure sensitive clef ultrasonic sensor element 20, Daia Fulham (four sides fixed), bridges the (two sides fixed) or force this embodiment the shape of the cantilever (one side fixed) is used generally well, square diaphragm using a 100. Further, using the sol 'gel film formation method by spin coating as the piezoelectric layer. The sol 'gel film-forming method, a composite metal alkoxide solution precursor solution viscosity adjusted by the hydrolysis and polycondensation or the like, and a film by spin Nkoto (gel film), that the film formation process for crystallizing heat treatment it is. The formation of the piezoelectric layer is after the anisotropic etching has been completed. Following the composition of the use Ru PZT sol-gel precursor solution above sol-gel film formation method.

[0026] [Table 1]

Composition solvent of the PZT sol-gel precursor solution 2-methoxyethanol

Pb component lead acetate trihydrate

Zr component Zr normal butoxide

Ti component Ti isopropoxide

PZT composition Pb: Zr: Ti = 115: 52: 48

15% wt as the concentration Pb Zr Ti O

[0027] (a) using a commercially available SOI as a starting substrate (Silicon On Insulator) semiconductor Wehachi-up 10 having the structure (active layer 2 m, the oxide film layer 1 mu m). 4 inches one substrate is used in dicing grayed into two. It is arranged four chips per wafer.

[0028] The wafer sided thermally oxidizing the eyes of insulation between the common electrode 16 (b) is a mask and the lower electrode during the anisotropic etching. At furnace temperature 1, 140 ° C, the first O 5. 0 liters

After dry Sani匕 5 minutes only 2 Z min, O (5. 0 liters

2 Z min) + H (4. 5 liters

18 2 Z min)

0 minutes to wet oxidation. The thickness of the oxide insulating layer 17 is about 1 μ m, EPW (Ethylenediamine Py rocatechol Water; Echirenjiamin (strong alkaline liquid)), and TMAH (Tetramethy lammonium Hydroxide; anisotropic etching by THEMA (organic alkaline developing solution) the thickness is to withstand ten minutes.

[0029] BHF a rear surface of the oxide film as a window for (c) anisotropic etching (Buffered Hydro-Fluoric ac id; buffer hydrofluoric acid (a weak acid liquid), i.e., hydrofluoric acid and fluoride ammonium - © beam of in the mixed solution, mainly a silicon Sani 匕物 to etch.) is etched with an etching solution of

[0030] (d) anisotropically etching the silicon of the support layer by EPW. Maintaining the temperature at approximately 115 ° C, subjected to about 5-6 hours etching, the thickness of the support layer and 50~100 / ζ πι. This is the thickness sufficiently withstand ultrasonic cleaning in the subsequent steps (g).

[0031] form a film by an RF sputtering apparatus PtZTi as (e) a common electrode 16 which is the lower electrode. Ar gas flow rate 44Sccm, in lPa atmosphere, first, 1 minute 500W of Ti, by 10 minutes sputtering Pt with 200W then obtain respectively a film thickness 0. 02 m and 0. 2 m. Photoresist lift-off by Iga such can be heated during casting to putter Jung using, as assessed by membrane-ray diffraction device manufactured (XRD (X- Ray Diflfractometer)), Pt (111) single orientation it was confirmed that the thin film of sufficient quality is formed in the common electrode 16 of the PZT ceramic thin film. The lift-off pattern, such that the electrode patterns overlap exactly with the diaphragm shape by the back surface of Etsuchin Guhoru performs patterns matching the duplex Masukuaraina.

[0032] (f) forming a film of the PZT ceramic thin film layer 17 as a piezoelectric layer by the sol 'gel film formation method. The PZT hydrofluoric nitric acid as a contact hole of the piezoelectric layer after film lower electrode (HF: HNO: H 0 = 1: 1

3 2

: 1) to etching. Is the time it takes the thickness of the PZT ceramics 1 mu m to etch at 10-30 seconds, the amount of side etching at this time is 5 to 10 mu m.

[0033] The (g) Pt as the inner electrode 18 and outer electrode 19 which is the upper electrode to form a film by an RF sputtering device, to putter Jung by lift-off. Film forming conditions are the same as step (e) the film thickness 0. 2 mu m.

[0034] form a square diaphragm structure by (h) anisotropic etching. Although the etching rate varies slightly, since almost stops etching at the I layer of the SOI structure, thereby completing the square diaphragm structure by etching in accordance with the most etching rate over preparative slow etch holes. Moreover, most degraded electrical properties of PZT ceramic thin layer 17 EPW boiling about 90 minutes by Sol 'gel film formation method is no, make sure that, Runode, the need to protect the surface during Etsuchin grayed nothingness ,.

[0035] (i) I layer of the SOI structure are essential as a stop layer of the above-mentioned anisotropic etching, so as the final structure can cause internal stresses, you removed after completion of the anisotropic etching There is a need. Since a normal Netsusani 匕膜, it removed by etching by BHF. After producing the sensor in the above process, to separate the chips by dicing the wafer, fixed to Bruno Kkeji to complete the sensor chip by bonding the electrodes.

[0036] After forming an ultrasonic sensor element 20 in the above process, to separate the chips by dicing the wafer 10, is fixed to Bruno Kkeji, to each electrode 18, 19 connected to connection conductors 31, 32 after connecting each drawer conductors respectively by bonding hand, and connecting the respective wires pry the terminal Tl, T2 (see FIGS. 1 and 4.), to complete the Sensachi' flop bonding.

[0037] In the vibration control apparatus of the piezoelectric resonant ultrasonic sensor element 20 according to the first embodiment, the detection electrode 18 provided in the central portion of the diaphragm, detection intellectual mechanical vibration by utilizing the piezoelectric effect Although it is, and in this embodiment is provided also around the vicinity of the detection electrode 18 for vibration control electrode 19. To suppress the duration of the vibration due to the resonance by using this. That is, as shown in Figure 1, the sensor output signal from the detection electrode 18 is amplified by the variable gain amplifier 31 is applied to the vibration control electrode 19 to generate a reverse phase vibration control signal (feedback signal) in particular from, to offset the vibrations in the reverse piezoelectric effect. Note that the output to the external circuit via the terminal T11 as also detection signals vibration control signal. Accordingly, the vibration plate itself can be taken out force applied to the vibration body which Nag that vibrates as the magnitude of the vibration control signal. Thus, the vibrating body is suppressed forcibly vibrated by inverse piezoelectric effect after vibrate slightly while being vibration suppression.

[0038] FIG. 5 is a piezoelectric resonant ultrasonic sensor element 20 of FIG. 1, an input ultrasonic signal of the signal waveform (a) when no by Ri vibration control the vibration control apparatus of FIG. 1, the amount seen scull of Daiafuramu and (b), is a signal waveform diagram showing a sensor output signal (c). Further, in FIG. 6 is pressure electrostatic resonant ultrasonic sensor element 20 of FIG. 1 and FIG. 2, to have vibration control by the vibration control apparatus of FIG. 1 and Kino input ultrasonic signal of the signal waveform (a), the Daiafuramu scull and see the amount (b), a signal waveform diagram illustrating the sensor output signal and (c). Comparative As is apparent from FIGS. 5 and 6, by applying the vibration control electrode 19 to generate a vibration control signal of the opposite phase, by canceling the vibrated by inverse piezoelectric effect, the vibration plate itself Nag can vibrate can be taken out as the magnitude of the vibration control signal force applied to the vibrating body, thereby, the vibration body suppress forcibly vibrated by inverse piezoelectric effect after vibrate slightly in the state of being vibration suppression It is.

[0039] Accordingly, in this embodiment, contact to the piezoelectric resonant ultrasonic sensor element 20, Te, high, while maintaining the Q value, it is possible to rapidly damp vibrations sustained, high sensitivity and high it is possible to achieve both the distance resolution. To do this, using the piezoelectric element can be used to both sensors (mechanical quantity → electric quantity conversion) and the drive source (converted electric quantity → dynamic quantity), constituting a vibration control system with a very simple structure can do.

[0040] As described above, according to this embodiment, it is possible to perform the damping of vibrations Nag that lowering the Q value effectively. Therefore, it constitutes a piezoelectric resonant sensor element as a good device with high sensitivity and damping property. In the prior art, the sensitivity in distance resolution priority in ultrasonic distance measurement has been sacrificed, high sensitivity and high range component resolution is compatible with the present embodiment. In the phased array for performing an angle measurement using the phase difference by using a plurality of piezoelectric resonant sensor element, the sensor oscillations long lasting it is required that the resonance frequencies coincide exactly, the It is relaxed restrictions on the resonance frequency by suppressing a short time vibration using embodiments, simplification of the manufacturing process, unnecessary trimming 'the frequency adjustment after the manufacturing, the reduction of products defect rate, the production of a total it is possible to lower the cost. [0041] Specific examples of this embodiment, can in used in distance measuring system using ultrasonic waves includes an angle scanning, proximity warning in the robot control, security systems, etc., three-dimensional measurement from the obstacle detection, three-dimensional shape measuring ambient It can also be used for space recognition, and the like.

[0042] Second Embodiment.

Figure 2 is a block diagram showing a structure of a vibration control apparatus for a piezoelectric resonant ultrasonic sensor element 20 is a second embodiment according to the present invention. Vibration control apparatus for a piezoelectric resonant ultrasonic sound wave sensor element 20 according to the second embodiment is different from the vibration control apparatus of FIG. 1, in place of the gain controller port over La 30 and the variable gain amplifier 31, one shot It is characterized by being configured with an oscillator 40 and a comparator 35 and the variable DC voltage source 36. Hereinafter, differences from the first embodiment Nitsu, detailed Te.

In [0043] Figure 2, to the inverting input terminal of the comparator 35, detected from the variable DC voltage source 36 threshold, a predetermined DC voltage as a value it is applied. Detection signals from the electrodes 18 of the ultrasonic sensor element 20 is input through the terminal T1 to the non-inverting input terminal of the comparator 35. Comparator 35, the detection signal inputted, as compared to the threshold value, when the higher-level force S threshold detection signal, i.e., detects the above detection signal by a predetermined threshold value when, it generates a pulse signal having a predetermined time width, and inputs to the control terminal of the switch 4 3 through the delay circuit 41. Here, the delay time of the delay circuit 41 td (see FIG. 7) is, for example, when a vibration wave to be detected half cycle to several cycles of ultrasound (preferably half cycle (of FIG. 7), two periods Ya 3 may be a period.) previously set to. When the pulse signal is input to the control terminal of the switch 4 3, switch 43 is turned on, the external circuit via the terminal T11 of the vibration control pulse signal as a sensor output signal from the variable DC voltage source 42 having a predetermined DC voltage and outputs to be marked addition to the vibration control external electrode 19 through the terminal T2. Thus, to cancel the vibrations in the reverse piezoelectric effect. Note that the output to the external circuit via the terminal T11 as also detection signals vibration control signal. Accordingly, the vibration plate itself Ru can retrieve the force applied to the vibrating body Nag that vibrates as the magnitude of the vibration control signal. Thus, the vibrating body is suppressed forcibly vibration by the reverse piezoelectric effect after oscillating half cycle increases.

[0044] FIG. 7 is a piezoelectric resonator ultrasonic sensor element 20 of FIG. 1 and FIG. 2, an input ultrasonic signal of the signal waveform (a) when the vibration control by the vibration control apparatus of FIG. 1, viewed scull of Daiafuramu amount (b), it is a signal waveform diagram showing a sensor output signal (c). 5 and Comparative force as is apparent in FIG. 7, by indicia addition to the vibration control electrode 19 to generate a vibration control pulse signal of opposite phase, by canceling the vibration in the reverse piezoelectric effect, the vibration plate itself is the force applied to the vibrating body Nag a child vibration can be taken out as the magnitude of the vibration control signal, by which, the vibrating body force vibrates the suppression to the reverse piezoelectric effect after oscillating half cycle increases that.

[0045] The above vibration control apparatus according to the second embodiment constructed as described has the same effect as the first embodiment.

[0046] Description of the optimal placement of the electrodes.

The following describes the optimum shape and arrangement method of piezoelectric resonant ultrasonic sensor element 20 according to the present embodiment the electrodes with reference to FIGS. 8 through 14 below.

[0047] FIG. 8 is a view for explanation of optimal placement of the electrodes of the piezoelectric resonant ultrasonic sensor element 20 according to the present embodiment, three-dimensional grayed showing the distribution of vibration amplitude and the in-plane distortion of Daiafuramu a rough, FIG. 9 is a diagram illustrating the scale is the degree of in-plane strain of the gray scale to be used in a graph showing the distribution of the in-plane strain in FIGS. 8 and 10 to 14. 8 Te smell, a diagonal leftward X direction position, a diagonal rightward Y direction position, showing the dynamic amplitude height direction vibration. Here, the in-plane strain is shown using the scale of FIG. Further, FIG. 10 is a plan view for explaining an arrangement of the detection electrodes and the oscillation control electrode in the piezoelectric resonant ultrasonic sensor element 20 according to this embodiment. Furthermore, Figure 11 is a plan view showing the shape of a substantially circular detecting electrodes indicating the optimal arrangement and the in-plane distortion distribution when parasitic capacitance is relatively small in FIG. 10, the parasitic capacitance is compared in FIG. 12 FIG. 10 target a shape of a circular sensing electrodes indicating the proper placement and in-plane distortion distribution equivalent to optimal arrangement is shown to plan view when small. Further, FIG. 13 is a plan view showing a substantially rectangular detection electrode shape close to an ellipse indicating the optimal arrangement and the in-plane distortion distribution when the parasitic capacitance is relatively large in Fig. 10, the parasitic capacitance 14 is 10 There is a plan view showing the shape of a substantially rectangular detection electrodes indicating the proper placement and in-plane strain distribution equivalent to optimal arrangement when relatively large.

[0048] In FIG. 8 shows the distribution of the vibration amplitude and the in-plane distortion of Daiafuramu to vibrate. Plane strain optic lobe, the opposite sign in the center portion and the peripheral portion of the Daiafuramu. Since piezoelectrically generated polarization is proportional to the in-plane distortion, it is preferred that the sensor electrode (detection electrode) is placed so as to correspond to the polarization distribution (distortion distribution), it is designed so that most output voltage becomes higher. The output voltage V is

Since the amount of charge generated in the piezoelectric divided by the electrostatic capacitance, it is desirable ideally to place an electrode area zero most polarization big points. However, since the actual sensor having a parasitic capacitance Cp, it is required to some extent over the electrode area. Here, the output voltage V is expressed by the following equation.

[0049] [number 1] l APdA

v =

C + C p

[0050] In this case,

[Number 2]

Λ

C = s- d

It is.

[0051] In addition, the parasitic capacitance Cp is a constant.

[0052] Here, delta [rho is the polarization occurring piezoelectric, A is the area of ​​the detection electrodes, C is the capacitance of the capacitor due to the detection electrodes, epsilon is the dielectric constant of the piezoelectric body, d is the thickness of the piezoelectric body. Further, the parasitic capacitance Cp does not depend on the area of ​​the detection electrode.

[0053] As can be seen from the above equation, it is necessary to increase the area A of about detecting electrode parasitic capacitance Cp is large. Vibration control electrode, it is necessary to suppress efficiently vibrated by inverse piezoelectric effect, it is necessary to possible large area. Therefore, the outside of the detection electrode area or shape is determined by the parasitic capacitance Cp and the like, should be installed to the One spread throughout the rest of the on the diaphragm region, the arrangement shown in Figure 10, for example.

[0054] Then, shows the actual electrode arrangement example in FIGS. 11 to 14. Here, the force actual structure shows only the shape of the inside of the detection electrodes, as shown in FIG. 10, it is necessary to install the dynamic control electrode vibration outside of the detection electrode. Figure 11 is an example of a case where the parasitic capacitance Cp is small, placing the electrode in a region centered around relatively centered. Its shape is a substantially circular is shape close to a circle to match the distribution shape distortion (polarization). Figure 12 is a shape equivalent thereto, an example where the electrode geometric roundness in the same area. Figure 13 is an example of a case where more parasitic capacitance Cp is large, the shape of the distortion (polarization) according to a distribution corners and edges rounded summer had a square shape (substantially rectangular or substantially elliptical near the ellipse). Figure 14 is a shape equivalent thereto, an example of the electrode was placed in the corners of the rounded square (substantially rectangular or substantially square).

[0055] As described above, the electrode 16, 16a facing the electrode 18 it is preferably formed in a central portion of the PZT ceramic thin film layer 17 of the piezoelectric body, and a circular, substantially circular, Ryaku楕 circle having a shape or substantially square shape.

[0056] Te differences Nitsu! / ヽ between this embodiment and the patent document 1.

Further, a piezoelectric resonant ultrasonic sensor element 20 according to the present embodiment, the following different points from the piezoelectric resonant ultrasonic sensor element disclosed in Patent Document 1 will be described with refer to FIGS. 15 to 18 .

[0057] FIG. 15 is a piezoelectric resonant ultrasonic sensor element 20 according to the present embodiment, the piezoelectric resonant ultrasonic sensor element disclosed in Patent Document 1 describing the differences (hereinafter referred to as Comparative Example.) And a diagram for a schematic plan view of the piezoelectric resonant ultrasonic sensor element 20, FIG. 16 is a longitudinal sectional view taken along line a-a 'in FIG. 15. Further, FIG. 17 is a diagram for explaining the differences between the pressure conductive resonant ultrasonic sensor element 20 according to the present embodiment, the piezoelectric resonant ultrasonic sensor element disclosed in Patent Document 1, It is a schematic plan view of a modification of the piezoelectric resonant ultrasonic sensor element 20, 18 Ru longitudinal sectional view der of B- B 'line in FIG. 17. Note that, in FIGS. 15 and 17, electrodes 16, 16a, for 16b, hidden visible such V, shown in solid lines for ease of forces illustrated should be shown by a dotted line in order, Ru. Further, in FIGS. 16 and 18 are schematic views, not such not show the members 11 to 15 individually.

[0058] That is, FIGS. 15 to 18 are schematic views of the electrode structure of the sensor element, the structure of the embodiment the present inventors have prototyped the role of structure in which force the electrodes of FIGS. 15 16 in order to clearly illustrate, it'll Chikarari cheaper of FIGS. 17 18. 15 and the terminal T3 in FIG. 16 corresponds to that short-circuiting the terminals Tla and the terminal T2a in FIGS. 17 and 18.

15 and 16 shows a sensor element according to the [0059] embodiment, the inner electrode 18 is connected to the electrode Tl via a connecting conductor 21, the outer electrode 19 is connected to the electrode T2 via a connection conductor 22 there. Further, the common electrode 16 opposed to the electrode 18, 19 is connected to the terminal T3 via a connecting conductor 25. In contrast, in FIGS. 17 and 18 shows a sensor element according to a modification, the common electrode 16 of the embodiment is divided into the corresponding electrode 16b to the electrode 16a and the electrode 1 9 facing the electrode 18. Here, the inner electrode 18 is connected to the electrode T1 via the connecting conductor 21, the outer electrode 19 is connected to the electrode T2 via a connection conductor 22, Ru. The counter electrode 16a facing the electrode 18 is connected to the terminal Tla via a connection conductor 25a, the counter electrode 16b facing the electrode 19 is connected to the terminal T2a via a connection conductor 25b.

[0060] That is, the electrode structure of the sensor diaphragm component in the sensor element according to the embodiment and the comparative example as expressed schematically FIGS. 15 to 18. The purpose difference below the sensor element according to the embodiment referred to as "vibration control sensor element", the sensor element according to a comparative example "polarization complementary sensor element", earthenware pots.

[0061] In the polarization complementary sensor element of the comparative example, it detects a potential difference between the terminals T1 and T2 as an output signal. Each electrode 18, 19 is used to detect the voltage produced by the piezoelectric effect. Electrode size La, Lb is parasitic capacitance Cpa corresponding thereto, taking into account the size of Cpb, are determined such that the output voltage V of the following equation is the maximum.

[0062] [number 3]

For Figure 15 16

- V T2a) the case of FIG. 17 18

[0063] Here, V is the detection voltage of the terminal T1, V is the detected voltage of the terminal T2, V is

A detected voltage of Tl T2 Tla terminals Tla, V is the detected voltage of the terminal Tib. 15 and FIG. 16

Tib

And definitive terminal T3, the terminal Tla in FIGS. 17 and 18, for Tib, need not be drawn out to the outside of the diaphragm is the practical use of the sensor element with the polarization complementary operation.

[0064] In contrast, in the vibration control sensor element according to the present embodiment detects a voltage generated by the piezoelectric effect between (when FIGS. 17 18) between the terminals T1 and Tla. Used to control the vibration by between (FIG. 17 when in FIG. 18) applies a vibration control voltage for controlling the reverse piezoelectric effect of the terminals T2 and T2a. Here, if the terminal Tla and the terminal Tib a same potential (e.g., ground potential), the terminals Tla, is the same as FIG. 15 and the terminal T3 in FIG 6 by connecting Tib. Electrode size of the electrode 18 connected to the terminal T1, to maximize the output voltage by the the same principle as described in the "split pole complementary sensor element", best service I's including the parasitic capacitance Cp . On the other hand, the electrode 19 connected to the terminal T2 shape, in order to maximize the effect of vibration control by the reverse piezoelectric effect, the maximum area that can be taken on the diaphragm (i.e., the remainder of the total area of ​​the electrodes 18 is not occupied) it is necessary to make the shape.

[0065] modification.

In the above embodiment, as an example of a piezoelectric resonant sensor element, a force that describes an ultrasonic sensor device 20 the present invention is not limited to this, a piezoelectric resonant sensor element, sonic sensor element, mechanical vibration it may be a sensor element.

[0066] In the above embodiments, the piezoelectric material used in the piezoelectric resonant ultrasonic sensor element, for example, using a ferroelectric a PZT ceramic thin layer 17, but Ru, the invention is not limited to this, for example, ZnO It even in it! / ヽ piezoelectric material is a ferroelectric material such as and A1N! / ,.

Industrial Applicability

[0067] As described above in detail, according to the vibration control device and a vibration control method of a piezoelectric resonant sensor element according to the first and third invention, reverse phase amplifies the detection signal by a predetermined gain by the vibration control signal is applied to the vibration control electrode, and controls so as to damp vibration of the detection signal when detecting the vibration wave, that Nag attenuated vibration lowers the Q value effectively It can be carried out. Therefore, it constitutes a piezoelectric resonant sensor element as a good device with high sensitivity and vibration damping characteristics. In the prior art, the sensitivity in distance resolution prioritized have your ultrasonic distance measurement has been sacrificed, high sensitivity and high distance resolution is compatible with the present invention. In the phased array for performing an angle measurement using the phase difference by using a plurality of piezoelectric resonant sensor element, the sensor oscillations long lasting it is required that its resonant frequency matches exactly, the invention using the relaxed restrictions on the resonance frequency by suppressing vibration in a short time, simplifying the manufacturing process, unnecessary trimming 'the frequency adjustment after the production, a decrease of products defective rate, manufacturing cost of the total it can be reduced. Further, according to the vibration control device and a vibration control method of a piezoelectric resonant sensor element according to the second and fourth aspects of the present invention, in response to the detection signal, delayed by a constant time Tokoro at the rising edge of the detection signal after the predetermined vibration control signal by applying to the vibration control electrode, and controls so as to damp vibration of the detection signal when detecting a vibration wave, the effect of the attenuation of vibration Nag that lowering the Q value it can be carried out in the manner. Therefore, it constitutes a piezoelectric resonant sensor element high sensitivity and vibration damping properties Yo, as a device. In the conventional technology, sensitivity distance resolution priority in ultrasonic distance measurement has been sacrificed, high sensitivity and high distance resolution is compatible with the present invention. Further, per cent Te, the phased array for performing an angle measurement using the phase difference by using a plurality of piezoelectric resonant sensor element, it is required that its resonant frequency matches exactly the sensor vibration is long lasting but limitation to the resonance frequency by suppressing a short time vibration using the present invention is reduced, simplification of the manufacturing process, unnecessary trimming 'the frequency adjustment after the production, a decrease of products failure rate, as a total it can reduce the cost of production.

Claims

The scope of the claims
[1] becomes in the piezoelectric body is sandwiched set at least one pair of electrodes, in the vibration control apparatus of the piezoelectric resonant sensor element that outputs a detection signal by detecting the vibration wave having a predetermined resonant frequency, the piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal
Further comprising a vibration control electrode formed in the vicinity of the electrodes,
By applying a vibration control signal of opposite phase to the vibration control electrodes by amplifying the detection signal by a predetermined gain, the amplifier means for controlling so as to damp vibration of the detection signal when it detects a vibration wave vibration control apparatus of the piezoelectric resonant sensor element characterized by having a
[2] The vibration control apparatus of the piezoelectric resonant sensor element of claim 1, wherein further comprising a control means for setting the gain of said amplifying means.
[3] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonance type according to claim 1, characterized in that it has a substantially elliptical shape or a substantially square shape vibration control device of the sensor element.
[4] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonant according to claim 2, characterized in that it has a substantially elliptical shape or a substantially square shape vibration control device of the sensor element.
[5] it will be a piezoelectric body is sandwiched set at least one pair of electrodes, in the vibration control apparatus of the piezoelectric resonant sensor element that outputs a detection signal by detecting the vibration wave having a predetermined resonant frequency, the piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal
Further comprising a vibration control electrode formed in the vicinity of the electrodes,
In response to the detection signal, after a delay of rise time forces a predetermined time of the detection signal, the predetermined vibration control signal by applying to the vibration control electrode, the detection signal when it detects a vibration wave vibration control apparatus of the piezoelectric resonant sensor element characterized by comprising a control means for damping vibrations.
[6] The control means, when the level of the detection signal exceeds a predetermined threshold, after delayed by substantially half period or several periods of the vibration wave, the predetermined vibration control pulse signal vibration control apparatus for a piezoelectric resonant sensor element of claim 5, wherein applying the vibration control electrode.
[7] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonance type according to claim 5, characterized in that it has a substantially elliptical shape or a substantially square shape vibration control device of the sensor element.
[8] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonant according to claim 6, characterized in that it has a substantially elliptical shape or a substantially square shape vibration control device of the sensor element.
[9] will be sandwiched set at least one pair of electrodes of the piezoelectric, the vibration control method of a piezoelectric resonant sensor element that outputs a detection signal by detecting the vibration wave having a predetermined resonant frequency, the piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal
Further comprising a vibration control electrode formed in the vicinity of the electrodes,
By applying a vibration control signal of opposite phase to the vibration control electrodes by amplifying the detection signal by a predetermined gain, the step of controlling so as to damp vibration of the detection signal when it detects a vibration wave vibration control method of the piezoelectric resonant sensor element which comprises.
[10] The vibration control method of a piezoelectric co-oscillating sensor device according to claim 9, wherein further comprising the step of setting the gain.
[11] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonance type according to claim 9, wherein it has a substantially elliptical shape or a substantially square shape vibration control method of the sensor element.
[12] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonant according to claim 10, characterized in that it comprises a substantially elliptical shape or a substantially square shape vibration control method of the sensor element.
[13] it becomes and clamping set at least one pair of electrodes of the piezoelectric, the vibration control method of a piezoelectric resonant sensor element that outputs a detection signal by detecting the vibration wave having a predetermined resonant frequency, the piezoelectric resonant sensor element, apart from the pair of electrodes for outputting the detection signal
Further comprising a vibration control electrode formed in the vicinity of the electrodes,
In response to the detection signal, after a delay of rise time forces a predetermined time of the detection signal, the predetermined vibration control signal by applying to the vibration control electrode, the detection signal when it detects a vibration wave vibration control method of the piezoelectric resonant sensor element which comprises a control step of controlling so as to damp vibrations.
[14] The control step, when the level of the detection signal exceeds a predetermined threshold, after delayed by substantially half period or several periods of the upper Symbol vibration wave, predetermined vibration control pulse signal the vibration control method of the piezoelectric resonant sensor element of claim 13, wherein applying to the vibration control electrode.
[15] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonant according to claim 13, characterized in that it has a substantially elliptical shape or a substantially square shape vibration control method of the sensor element.
[16] the pair of electrodes is formed in a central portion of the piezoelectric body and circular, substantially circular, piezoelectric resonant according to claim 14 characterized in that it has a substantially elliptical shape or a substantially square shape vibration control method of the sensor element.
PCT/JP2006/309494 2005-05-25 2006-05-11 Oscillation controller for piezoelectric resonant sensor element WO2006126401A1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010522616A (en) * 2007-03-26 2010-07-08 レモン メディカル テクノロジーズ, リミテッド Biased acoustic switches for implantable medical devices
JP2013098724A (en) * 2011-10-31 2013-05-20 Konica Minolta Holdings Inc Piezoelectric device, ultrasonic probe and manufacturing method of piezoelectric device
US8934972B2 (en) 2000-10-16 2015-01-13 Remon Medical Technologies, Ltd. Acoustically powered implantable stimulating device
US9024582B2 (en) 2008-10-27 2015-05-05 Cardiac Pacemakers, Inc. Methods and systems for recharging an implanted device by delivering a section of a charging device adjacent the implanted device within a body
WO2016167003A1 (en) * 2015-04-13 2016-10-20 株式会社村田製作所 Ultrasonic sensor and method for controlling same

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JP2005039720A (en) * 2003-07-18 2005-02-10 Osaka Industrial Promotion Organization Piezoelectric ultrasonic sensor element

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JPS61223683A (en) * 1985-03-29 1986-10-04 Nec Corp Ultrasonic device and its driving method
JPH03276084A (en) * 1990-03-27 1991-12-06 Yokogawa Electric Corp Ultrasonic range finder
JP2005039720A (en) * 2003-07-18 2005-02-10 Osaka Industrial Promotion Organization Piezoelectric ultrasonic sensor element

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8934972B2 (en) 2000-10-16 2015-01-13 Remon Medical Technologies, Ltd. Acoustically powered implantable stimulating device
JP2010522616A (en) * 2007-03-26 2010-07-08 レモン メディカル テクノロジーズ, リミテッド Biased acoustic switches for implantable medical devices
US9024582B2 (en) 2008-10-27 2015-05-05 Cardiac Pacemakers, Inc. Methods and systems for recharging an implanted device by delivering a section of a charging device adjacent the implanted device within a body
JP2013098724A (en) * 2011-10-31 2013-05-20 Konica Minolta Holdings Inc Piezoelectric device, ultrasonic probe and manufacturing method of piezoelectric device
WO2016167003A1 (en) * 2015-04-13 2016-10-20 株式会社村田製作所 Ultrasonic sensor and method for controlling same
JPWO2016167003A1 (en) * 2015-04-13 2017-05-25 株式会社村田製作所 Ultrasonic sensors, and its control method

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