JPH11220378A - Ultrasonic switching element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a switching element by applying an ultrasonic touch panel. SOLUTION: When an electric signal is inputted to an interdigital electrode 3, a surface acoustic wave is excited nearby the top surface of a piezoelectric substrate 1, propagated to the upper end surface of a nonpiezoelectric plate 2, and then converted to electric signals E1a and E1b by parts R1a and R1b of an interdigital electrode 4. Interdigital electrodes 3 and 3 form ultrasonic wave propagation paths Z1a and Z1b on the upper end surface of the nonpiezoelectric plate 2. If the upper end surface of the nonpiezoelectric substrate 2 is brought into contact and the ultrasonic wave propagation path Z1b is cut off, the electric signal E1a is outputted from the interdigital electrode 4 and when the ultrasonic wave propagation path Z1a is cut off, the electric signal E1b is outputted. Thus, the electric signals can be generated by bringing the upper end surface of the nonpiezoelectric substrate 2 into contact, so the function of a switch is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic switching element that generates an electric signal by contacting a non-piezoelectric plate.

2. Description of the Related Art A conventional touch panel based on an ultrasonic method utilizes the fact that a surface acoustic wave is excited on a non-piezoelectric plate and the surface acoustic wave is attenuated by contact with the non-piezoelectric plate. Conventional methods of exciting a surface acoustic wave to a non-piezoelectric plate include a method of indirectly exciting a wedge-shaped transducer using a bulk wave oscillator, and a method of directly exciting a piezoelectric thin film transducer. These conventional ultrasonic touch panels have problems in response time, sensitivity, durability, machining accuracy, workability, mass productivity, etc., the frequency range used is limited, the signal processing method is complicated, and remote control Is difficult. Therefore, it was difficult to produce a switching element by applying a touch panel based on an ultrasonic method.

Heretofore, it has been difficult to produce a switching element by applying an ultrasonic touch panel. An object of the present invention is excellent in workability, durability and mass productivity, low power consumption, short response time, simple signal processing, small circuit size, small size and light weight. An object of the present invention is to provide an ultrasonic switching element which is excellent in ease of use and can transmit a radio signal.

An ultrasonic wave according to claim 1, wherein:
Switching elements include piezoelectric substrates, non-piezoelectric plates,
Ultrasonic Switching Element Consisting of Interdigital Electrodes and Output ID
Wherein the input and output interdigital transducers are
A lower end surface of the non-piezoelectric plate, provided on an upper end surface of the piezoelectric substrate;
Are the input and output terminals on the upper end surface of the piezoelectric substrate.
The output IDB is fixed through the IDL
The intersection area of the electrode fingers of the electrodes is one group R_i(I =
1) or N groups R_i(I = 1,
2,..., N) and the two groups R_iAnd R_{(i + 1)}
(N-1) parts Q sandwiched between_i｛I = 1,2, ...
, (N-1)}, and each group R_iIs two
Part R_iaAnd R_ibAnd the portion R sandwiched between them_{i m}Or
The part R_iaAnd R_ibFor each electrode finger
The direction is parallel to the direction of the electrode fingers of the input IDT,
Part R_iaAnd R_ibEach electrode cycle length is
Equal to the electrode period length P of the interdigital transducer,
_imOf the input interdigital transducer is angled with respect to the input
the portion R_imDirection perpendicular to the electrode finger
Length of electrode finger P at_RNIs the electrode period length P and cos α
With the product R_imThe electrode intersection width
Part R_imWidth L in the direction of the electrode finger_RPAnd for the input
Intersection width L of the interdigital transducer in the direction parallel to the electrode fingers_RNWith
There are two types, the intersection width L_RPIs the intersection width L_RNAnd se
equal to the product of cα and half of the electrode period length P
Is equal to the product of_iThe electrode finger is
Has an inclination of ± β with respect to the electrode fingers of the input IDT
And the part Q_iElectrode finger in a direction perpendicular to the electrode finger
Period length P_QNIs equal to the product of the electrode period length P and cosβ.
And the part Q_iThe above-mentioned portion Q_iElectrode
Intersection width L in finger direction_QPAnd the input IDT
Intersection width L in the direction parallel to the electrode finger_QNThere are two types,
The intersection width L_QPIs the intersection width L_QNEqual to the product of
And the portion R_iaAnd R_ibEach electrode intersection width,
The intersection width L_RNAnd the intersection width L_QNThe sum of
The electrode intersecting width L of the IDT,
The interdigital transducer has a circumference substantially corresponding to the electrode cycle length P.
By receiving an electric signal of a wave number, the piezoelectric substrate
Near the surface of the upper end face of the electrode, and substantially equal to the electrode period length P.
Excitation of surface acoustic waves having a different wavelength
Propagating to the upper end surface of the non-piezoelectric plate, the portion R_iaand
R_ibConverts the surface acoustic wave into an electric signal E_iaAnd E_ib(I
= 1, 2,..., N),
E_iaAnd E_ibOf the electrical signal generated by combining
The amplitude is zero and the input and output IDTs
Is the portion R on the upper end surface of the non-piezoelectric plate._ia
And R_ibUltrasonic propagation path Z corresponding to each_iaand
Z_ib(I = 1, 2,..., N), and
The drooping electrode is a finger or a finger on the upper end surface of the non-piezoelectric plate.
The ultrasonic wave propagation path Z_iaAnd Z_ibOut of
One of Z_XaThe ultrasonic propagation path only when
Z_XaUltrasonic propagation path Z paired with_XbElectrical signal E corresponding to
_XbOr contact the upper end face of the non-piezoelectric plate.
Touch the ultrasonic wave propagation path Z_XbOnly when is interrupted,
The ultrasonic wave propagation path Z_XaElectrical signal E corresponding to_XaOutput
You. The ultrasonic switching element according to claim 2 is a piezoelectric switching element.
From substrates, non-piezoelectric plates, input and output IDTs
An ultrasonic switching element comprising:
And an output IDT are provided on the upper end surface of the piezoelectric substrate.
The lower end surface of the non-piezoelectric plate is the upper end of the piezoelectric substrate.
Fixed to the surface via the input and output IDTs
The intersection area of the electrode fingers of the input IDT is
N parts A_i(I = 1, 2,..., N) and before two
Note A_iAnd A_{(i + 1)}(N-1) parts sandwiched between
B_i{I = 1, 2,..., (N-1)}
The intersection area of the electrode fingers of the output IDT is (N + 1)
Pieces C_i{I = 1, 2,..., (N + 1)} and 2
Two said parts C_iAnd C_{(i + 1)}N parts D sandwiched between
_i(I = 1, 2,..., N) and the portion A_iNo electricity
The direction of the extreme finger is the part C_iParallel to the direction of the electrode fingers of
Note B_iThe electrode finger of the part A_iAngle -β
The part B_iIn the direction perpendicular to the electrode finger
Period length P of the electrode finger_BNIs the part A_iAnd C_iElectrode
Equal to the product of the period length P and cosβ,_iElectrode exchange
In the difference width, the part B_iWidth L in the direction of the electrode finger_BP
And the portion A_iWidth L in the direction parallel to the electrode finger_BN
And the intersection width L_BPIs the intersection width L_BNWhen
equal to the product of secβ and the part D_iThe electrode finger is the part
C_iHas an inclination of an angle α with respect to the electrode finger of_iNo electricity
Period length P of the electrode finger in the direction perpendicular to the pole finger_DNIs the
Equal to the product of the pole period length P and cos α,_iElectrode
The crossing width includes the part D_iWidth L in the direction of the electrode finger
_DPAnd the portion C_iWidth L in the direction parallel to the electrode finger
_DNAnd the intersection width L_DPIs the intersection width L
_DNOf the electrode period P
Is equal to the product of half of_iElectrode finger
Intersection width and said intersection width L_BNIs the sum of the part C_i
The electrode finger intersection width and the intersection width L_DNAlmost equal to the sum of
Preferably, the input IDT has an electrode period length P.
By inputting an electric signal of almost the corresponding frequency
The electrode periphery is located near the top surface of the piezoelectric substrate.
Exciting a surface acoustic wave having a wavelength substantially equal to the period length P,
The surface acoustic wave is propagated to the upper end surface of the non-piezoelectric plate, and
The output interdigital transducer converts the surface acoustic wave into N electric waves.
Signal E_ia(I = 1, 2,..., N) and N electrical signals
No. E_ib(I = 1, 2,..., N).
No. E_iaAnd E_ibSignal generated by combining
Is zero, and the input and output IDTs are
The poles are N supersonic on the upper end face of the non-piezoelectric plate.
Wave propagation path Z_ia(I = 1, 2,..., N) and more than N
Sound propagation path Z_ib(I = 1, 2,..., N)
The output IDT is formed on the upper end surface of the non-piezoelectric plate.
The ultrasonic wave propagation path Z comes in contact with a human finger or an object._iaand
Z_ibOne of the Z_XaOnly when is interrupted
Sound propagation path Z_XaUltrasonic propagation path Z paired with_XbCorresponding to
Electric signal E_XbOr output of the non-piezoelectric plate
The ultrasonic wave propagation path Z_XbWas shut off
Only when the ultrasonic wave propagation path Z_XaElectrical signal E corresponding to
_XaIs output. The ultrasonic switching element according to claim 3.
The input and output piezoelectric substrates, non-piezoelectric plates, and inputs
Ultrasonic Switching Consisting of Inverter and Output IDTs
An element, wherein the input and output IDTs are
One plate surface of each of the input and output piezoelectric substrates
The input and output piezoelectric substrates are provided in the
The one plate surface of each of the input and output piezoelectric substrates
Or to the upper end surface of the non-piezoelectric plate via the other plate surface
An intersecting area of the electrode fingers of the output IDT, which is fixed.
Is one group R_i(I = 1) or
N groups R_i(I = 1, 2,..., N) and two
The group R_iAnd R_{(i + 1)}(N-1) pieces sandwiched between
Part Q_i{I = 1,2, ..., (N-1)}
Each of the groups R_iIs the two parts R_iaAnd R
_ibAnd the portion R sandwiched between them_{i m}The part R
_iaAnd R_ibThe direction of each electrode finger is the input
Parallel to the direction of the electrode fingers of the spiral electrode,_iaand
R_ibEach electrode cycle length is the same as that of the input IDT.
The portion R is equal to the electrode period length P._imElectrode fingers
It has an angle α with respect to the electrode fingers of the
Notation R_imLength of the electrode finger in the direction perpendicular to the electrode finger
P_RNIs equal to the product of the electrode period length P and cos α,
Notation R_imIn the electrode cross width, the portion R_imOf the electrode finger
Intersection width L in direction_RPAnd an electrode of the input IDT
Intersection width L in the direction parallel to the finger_RNThere are two types,
Intersection width L_RPIs the intersection width L_RNEqual to the product of
And the product of half of the electrode period length P and cosec α
Equal, said part Q_iThe electrode fingers of
The angle ± β with respect to the pole electrode finger,_iof
Period length P of the electrode finger in the direction perpendicular to the electrode finger_QNIs
Equal to the product of the electrode period length P and cosβ,_iNo electricity
The part Q_iCross width in the direction of the electrode finger
L_QPAnd a direction parallel to the electrode fingers of the input IDT
Intersection width L at_QNAnd the intersection width L_QPIs before
Notation width L_QNIs equal to the product of_iaYou
And R_ibEach electrode intersection width and the intersection width L_RNWhen,
The intersection width L_QNIs the sum of the input IDT electrodes.
The input IDT is substantially equal to the pole intersection width L,
An electric signal having a frequency substantially corresponding to the electrode cycle length P is input.
By being applied, the electrode periphery is applied to the input piezoelectric substrate.
Exciting a surface acoustic wave having a wavelength substantially equal to the period length P,
Propagating the surface acoustic wave to the upper end surface of the non-piezoelectric plate
After that, the light is propagated to the output piezoelectric substrate, and the portion R_iaYou
And R_ibConverts the surface acoustic wave into an electric signal E_iaAnd E_ib
(I = 1, 2,..., N).
Signal E_iaAnd E_ibSignal generated by synthesizing
The signal amplitude is zero, and the input and output
The electrode is located on the upper end surface of the non-piezoelectric plate,
R_iaAnd R_ibUltrasonic propagation path Z corresponding to each_iaYou
And Z_ib(I = 1, 2,..., N), and the output
The interdigital transducer is configured such that the upper end surface of the non-piezoelectric plate is
Or the ultrasonic wave propagation path Z_iaAnd Z_ibof
One of them Z_XaThe ultrasonic transmission is only performed when the
Carriage Z_XaUltrasonic propagation path Z paired with_XbTelecommunications corresponding to
No. E_XbOr the upper end face of the non-piezoelectric plate
And the ultrasonic wave propagation path Z_XbWhen was cut off
The ultrasonic propagation path Z_XaElectrical signal E corresponding to_XaOut
Power. The ultrasonic switching element according to claim 4,
Input and output piezoelectric substrates, non-piezoelectric plates, input and
Ultrasonic switching element consisting of interdigital electrodes for output
The input and output interdigital transducers are
Provided on one of the piezoelectric substrates for force and output
Wherein the input and output piezoelectric substrates are
And the one plate surface of each of the piezoelectric substrates for output or
Affixed to the upper end surface of the non-piezoelectric plate via the other plate surface
The intersection area of the electrode fingers of the input IDT is N
Part A_i(I = 1, 2,..., N) and the two
Part A_iAnd A_{(i + 1)}(N-1) parts B sandwiched between
_i{I = 1, 2,..., (N-1)}.
The intersecting area of the electrode fingers of the force interdigital transducer is (N + 1)
Part C of_i{I = 1,2, ..., (N + 1)} and two
The part C of_iAnd C_{(i + 1)}N parts D sandwiched between_i
(I = 1, 2,..., N) and the portion A_iNo electricity
The direction of the extreme finger is the part C_iParallel to the direction of the electrode fingers of
Note B_iThe electrode finger of the part A_iAngle -β
The part B_iIn the direction perpendicular to the electrode finger
Period length P of the electrode finger_BNIs the part A_iAnd C_iElectrode
Equal to the product of the period length P and cosβ,_iElectrode exchange
In the difference width, the part B_iWidth L in the direction of the electrode finger_BP
And the portion A_iWidth L in the direction parallel to the electrode finger_BN
And the intersection width L_BPIs the intersection width L_BNWhen
equal to the product of secβ and the part D_iThe electrode finger is the part
C_iHas an inclination of an angle α with respect to the electrode finger of_iNo electricity
Period length P of the electrode finger in the direction perpendicular to the pole finger_DNIs the
Equal to the product of the pole period length P and cos α,_iElectrode
The crossing width includes the part D_iWidth L in the direction of the electrode finger
_DPAnd the portion C_iWidth L in the direction parallel to the electrode finger
_DNAnd the intersection width L_DPIs the intersection width L
_DNOf the electrode period P
Is equal to the product of half of_iElectrode finger
Intersection width and said intersection width L_BNIs the sum of the part C_i
The electrode finger intersection width and the intersection width L_DNAlmost equal to the sum of
Preferably, the input IDT has an electrode period length P.
By inputting an electric signal of almost the corresponding frequency
The electrode period length P is substantially equal to the electrode period length P on the input piezoelectric substrate.
Excitation of surface acoustic waves having a different wavelength
After propagating to the upper end surface of the non-piezoelectric plate, the output
Propagated to the piezoelectric substrate, the output IDT is
The surface acoustic wave is converted into N electrical signals E_ia(I = 1,2, ...,
N) and N electrical signals E_ib(I = 1,2, ...,
N) and converts the electric signal E_iaAnd E_ibCompose
The amplitude of the resulting electrical signal is zero,
And the output interdigital transducer are provided on the non-piezoelectric plate.
At the end face, N ultrasonic propagation paths Z_ia(I = 1, 2,
..., N) and N ultrasonic propagation paths Z_ib(I = 1,
2,..., N), and the output IDT is
A finger or an object contacts the upper end surface of the non-piezoelectric plate.
The ultrasonic wave propagation path Z_iaAnd Z_ibOne of the Z_XaIs blocked
Only when the ultrasonic wave propagation path Z_XaPair with
Ultrasonic wave propagation path Z_XbElectrical signal E corresponding to_XbOutput
Or contact the upper end surface of the non-piezoelectric plate and
Sound propagation path Z_XbThe ultrasonic transmission is only performed when the
Carriage Z_XaElectrical signal E corresponding to_XaIs output. Claim 5
The ultrasonic switching element according to the above, the thickness of the piezoelectric substrate
D is approximately three times or more the electrode cycle length P,
The thickness h of the piezoelectric plate is smaller than the electrode cycle length P,
The phase velocity of a surface acoustic wave propagating on a non-piezoelectric plate alone is
Smaller than the phase velocity of the surface acoustic wave propagating on the piezoelectric substrate alone
The direction of the polarization axis of the piezoelectric substrate is the direction of its thickness d.
Direction, and the surface acoustic wave has a zero-order mode and a
The higher order mode wave, the elastic surface of the zero order mode
The phase velocity of the wave is the piezoelectric substrate in an electrically shorted state.
The speed is almost equal to the speed of the Rayleigh wave propagating to
The phase velocity of surface acoustic waves of higher order modes is
Rayleigh propagating to the piezoelectric substrate alone in the open state
It is almost equal to the speed of the waves. The ultrasonic switch according to claim 6.
The thickness d of each piezoelectric substrate is equal to the electrode period.
Is smaller than the length P, and the thickness h of the non-piezoelectric plate is
It is almost three times or more the period length P and propagates to the non-piezoelectric plate alone.
The phase velocity of the surface acoustic wave is transmitted to each of the piezoelectric substrates.
Each of the piezoelectric elements is larger than the phase velocity of the surface acoustic wave to be carried.
The direction of the polarization axis of the substrate is parallel to the direction of its thickness d.
The surface acoustic wave is a first-order or higher-order mode wave.
The phase velocities of surface acoustic waves in the first and higher modes are
It is almost equal to the speed of Rayleigh wave propagating in the non-piezoelectric plate alone
No. The ultrasonic switching element according to claim 7, wherein
And output piezoelectric substrates, non-piezoelectric plates, input and output
Ultrasonic switching element consisting of interdigital electrodes
The input and output IDTs are used for the input.
And one of the piezoelectric substrates for output
The input and output piezoelectric substrates are connected to the input and output piezoelectric substrates.
And the one surface or each of the piezoelectric substrates for output
Secured to one of the non-piezoelectric plates via the other plate surface
The intersection area of the electrode fingers of the output IDT is
One group R_i(I = 1) or N
Group R_i(I = 1, 2,..., N) and the two
Group R_iAnd R_{(i + 1)}(N-1) parts sandwiched between
Minute Q_i{I = 1,2, ..., (N-1)}
Each group R_iIs the two parts R_iaAnd R_ibAnd it
Part R sandwiched between_{i m}The part R_iaAnd R
_ibThe direction of each electrode finger is the same as that of the input IDT.
Parallel to the direction of the electrode fingers, the portion R_iaAnd R_ibEach
The electrode cycle length is the electrode cycle length of the input IDT.
P equal to the part R_imElectrode finger is the input blind
The electrode R has an inclination of an angle α with respect to the electrode finger, and the portion R_im
Of the electrode finger in the direction perpendicular to the electrode finger_RNIs before
Equal to the product of the electrode period length P and cos α,_im
In the electrode cross width, the portion R_imIn the direction of the electrode finger
Difference width L_RPParallel to the electrode fingers of the input IDT
Intersection width L in direction_RNAnd the intersection width L_RP
Is the intersection width L_RNAnd secα, and
Equal to the product of half of the electrode period length P and cosec α,
Note Q_iAre the electrode fingers of the input IDT.
Has an inclination of ± β with respect to_iDirectly to the electrode finger
Period length P of the electrode finger in the intersecting direction_QNIs the electrode cycle length
Equal to the product of P and cosβ, the part Q_iThe electrode intersection width
Is the part Q_iWidth L in the direction of the electrode finger_QPAnd before
Intersection width of input IDT in the direction parallel to the electrode fingers
L_QNAnd the intersection width L_QPIs the intersection width L
_QNIs equal to the product of_iaAnd R_ibSo
Each electrode intersection width and the intersection width L_RNAnd the intersection width
L_QNIs the electrode intersection width L of the input IDT.
And the thickness d of each piezoelectric substrate is equal to the electrode period.
The input IDT is smaller than the length P,
The input piezoelectric substrate and the non-
Two-layer structure part B composed of a piezoelectric plate_TTo excite the ultrasonic waves
After propagating ultrasonic waves to the non-piezoelectric plate, the output piezoelectric
Two-layer structure part B composed of a substrate and the non-piezoelectric plate_RPropagated to
The part R_iaAnd R_ibConverts the ultrasonic wave into an electric signal
E_iaAnd E_ib(I = 1, 2,..., N)
In other words, the electric signal E_iaAnd E_ibBy combining
The resulting electrical signal has an amplitude of zero,
The output IDT is formed on the non-piezoelectric plate,
Minute R_iaAnd R_ibUltrasonic propagation path Z corresponding to each_ia
And Z_ib(I = 1, 2,..., N).
The interdigital transducer is one of the non-piezoelectric plates.
The ultrasonic wave propagation path Z by contacting the surface with a human finger or an object;_iaYou
And Z_ibOne of the Z_XaOnly when is shut off
Ultrasonic propagation path Z_XaUltrasonic propagation path Z paired with_XbCompatible with
Electrical signal E_XbOr output of the non-piezoelectric plate
The ultrasonic wave propagation path Z_XbBut
Only when interrupted, the ultrasonic wave propagation path Z_XaCorresponding to
Electric signal E_XaIs output. An ultrasonic wave according to claim 8.
The switching elements consist of input and output piezoelectric substrates,
Ultrasound consisting of plate, input and output interdigital transducers
A switching element, wherein the input and output
The drooping electrodes are the input and output piezoelectric substrates, respectively.
The input and output piezoelectric
The substrate is in front of each of the input and output piezoelectric substrates.
The non-piezoelectric device is connected to one of the plate surfaces or the other plate surface.
The input IDT is fixed to one surface of the plate,
The intersection area of the electrode fingers is N parts A_i(I = 1,2, ...
.., N) and the two parts A_iAnd A_{(i + 1)}Sandwiched between
(N-1) parts B_i｛I = 1, 2,..., (N−
1) Interchange of electrode fingers of the output IDT
The difference area is composed of (N + 1) parts C_i｛I = 1,2, ...
.., (N + 1)} and the two parts C_iAnd C_{(i + 1)}
N parts D sandwiched between_i(I = 1,2, ..., N)
The part A_iThe direction of the electrode finger is the part C_iNo electricity
Parallel to the direction of the extreme finger, the part B_iThe electrode finger is the part
A_iThe electrode finger has an inclination of an angle -β, and the portion B_iof
Period length P of the electrode finger in the direction perpendicular to the electrode finger_BNIs
Part A_iAnd C_iEqual to the product of the electrode period length P and cosβ
And the part B_iIn the electrode intersection width, the portion B_iElectrode
Intersection width L in finger direction_BPAnd the portion A_iFlat on the electrode finger
Intersection width L in line direction_BNThere are two types, the intersection width
L_BPIs the intersection width L_BNIs equal to the product of
Minute D_iElectrode finger is the part C_iOf the angle α with respect to the electrode finger
And the portion D_iElectrode in the direction perpendicular to the electrode finger
Finger cycle length P_DNIs the product of the electrode period length P and cosα.
Equal, said part D_iIn the electrode intersection width, the portion D_iof
Intersection width L in the direction of the electrode finger_DPAnd the portion C_iElectrode finger
Width L in the direction parallel to_DNThere are two types of
Difference width L_DPIs the intersection width L_DNEqual to the product of
Both are equal to the product of half the electrode period length P and cosec α.
Part A_iWidth of the electrode finger and the width of said intersection
L_BNIs the sum of the part C_iElectrode finger cross width and front
Notation width L_DNAnd the thickness of each piezoelectric substrate
D is smaller than the electrode cycle length P, and
The reed-shaped electrode receives the electric signal to
-Layer structure B composed of a piezoelectric substrate for use and the non-piezoelectric plate_TSuper
Excited the sound wave and propagated the ultrasonic wave to the non-piezoelectric plate
Then, a two-layer structure including the piezoelectric substrate for output and the non-piezoelectric plate
Structure B_RAnd the output IDT is
The ultrasonic wave is converted into N electrical signals E_ia(I = 1, 2,..., N)
And N electrical signals E_ib(I = 1,2, ..., N)
Convert the electrical signal E_iaAnd E_ibTo synthesize
The resulting electrical signal has an amplitude of zero,
In the non-piezoelectric plate, the number of interdigital electrodes for output and N
Ultrasonic propagation path Z_ia(I = 1, 2,..., N) and N
Ultrasonic propagation paths Z_ib(I = 1, 2,..., N)
The output IDT may be any one of the non-piezoelectric plates.
The ultrasonic wave is transmitted when a finger or an object comes into contact with one of the plate surfaces.
Carriage Z_iaAnd Z_ibOne of the Z_XaIs interrupted
Only the ultrasonic propagation path Z_XaUltrasonic propagation path paired with
Z_XbElectrical signal E corresponding to_XbOr output the
One of the non-piezoelectric plates is brought into contact with one
Carriage Z_XbThe ultrasonic propagation path Z only when
_XaElectrical signal E corresponding to_XaIs output. Claim 9
The ultrasonic switching element is a polarization axis of each of the piezoelectric substrates.
Is parallel to the direction of the thickness d, and the non-piezoelectric plate
Is smaller than the thickness d of each of the piezoelectric substrates,
The phase velocity of the elastic wave propagating to the non-piezoelectric plate alone is
Greater than the phase velocity of the elastic wave propagating to the circuit board alone,
The input IDT is substantially opposite to the electrode cycle length P.
By receiving an electric signal of a corresponding frequency,
Two-layer structure B_TA wavelength approximately equal to the electrode period length P
Exciting the elastic wave having, the elastic wave in the non-piezoelectric plate
After propagating, the two-layer structure B_RPropagates the bullet
The sex wave is S₀Mode and first and higher order waves,
The two-layer structure B_TPhase velocity of the elastic wave excited in
Is the frequency f of the elastic wave and the thickness d of each piezoelectric substrate.
When the product fd is near zero₀Mode of elastic wave
Phase velocity V_{fd = 0}Is almost equal to The supersonic according to claim 10.
The wave switching element is arranged in the direction of the polarization axis of each piezoelectric substrate.
Is parallel to the direction of the thickness d, and the thickness of the non-piezoelectric plate
h is substantially equal to the thickness d of each of the piezoelectric substrates,
The phase velocity of the elastic wave propagating to the plate alone is
The phase velocity is almost equal to the phase velocity of the elastic wave propagating
The interdigital transducers substantially correspond to the electrode period length P.
By receiving an electric signal of a frequency, the two-layer structure is used.
Structure B_THas a wavelength substantially equal to the electrode period length P
Excites an elastic wave and propagates the elastic wave through the non-piezoelectric plate.
And then the two-layer structure B_RAnd the elastic wave is
S₀Mode and first and higher order waves,
Layer structure B_TThe phase velocity of the elastic wave excited in
The product f of the frequency f of the elastic wave and the thickness d of each piezoelectric substrate
S when d is near zero₀Phase velocity of mode elastic waves
Degree V_{fd = 0}Is almost equal to An ultrasonic switch according to claim 11.
The direction of the polarization axis of each piezoelectric substrate is the
The thickness d of the non-piezoelectric plate is parallel to the direction of the thickness d.
The thickness of each piezoelectric substrate is greater than d and
It is smaller than twice the thickness d of the substrate.
The phase velocity of the propagating elastic wave is transmitted to each piezoelectric substrate alone.
Smaller than the phase velocity of the elastic wave to be carried, and
The reed-shaped electrode has a frequency substantially corresponding to the electrode cycle length P.
By receiving an electric signal, the two-layer structure B_T
An elastic wave having a wavelength substantially equal to the electrode period length P
After exciting and propagating the elastic wave through the non-piezoelectric plate,
The two-layer structure B_RAnd the elastic wave is S₀mode
And the first-order or higher-order mode wave, the two-layer structure portion B
_TThe phase velocity of the elastic wave excited in
The product fd of the frequency f and the thickness d of each piezoelectric substrate is close to zero.
S when nearby₀Mode velocity V of elastic wave_{fd = 0}When
Almost equal. An ultrasonic switching element according to claim 12.
The input and output piezoelectric substrates are
And the other plate surface of each piezoelectric substrate for output
Is fixed to one surface of the non-piezoelectric plate through
The interface between the circuit board and the non-piezoelectric plate is electrically open.
The direction of the polarization axis of each piezoelectric substrate is
Of the non-piezoelectric plate is parallel to the direction of the
The thickness h is substantially equal to the thickness d of each of the piezoelectric substrates, and
Is smaller than that, and the non-piezoelectric plate is
The phase velocity of the transverse wave propagating through the body is transmitted to each of the piezoelectric substrates alone.
Less than or equal to the phase velocity of the shear wave
The input IDT is made of a material, and the input IDT is
Inputting an electric signal of a frequency substantially corresponding to the length P
The two-layer structure B_TApproximately equal to the electrode cycle length P
An SH wave having an equal wavelength is excited, and the SH wave is
After propagating through the non-piezoelectric plate, the two-layer structure B_RPropagate to
The SH wave is in the 0th-order mode and the first-order or higher-order modes.
The phase velocity of the SH wave is the same as that of the non-piezoelectric plate.
Shear wave velocity propagating in the body and propagating to each of the above piezoelectric substrates
About the average value of the shear wave velocity. Claim 13
Of the ultrasonic switching element for the input and output
A piezoelectric substrate, the input and output piezoelectric substrates respectively
One of the non-piezoelectric plates through the other plate surface
Surface, and the interface of each piezoelectric substrate with the non-piezoelectric plate
Is in an electrically short circuit state, and the polarization axis of each piezoelectric substrate is
The direction is parallel to the direction of the electrode fingers of the input IDT.
And the thickness h of the non-piezoelectric plate is the thickness of each of the piezoelectric substrates.
d and twice the thickness d of each piezoelectric substrate
And the non-piezoelectric plate is transmitted to the non-piezoelectric plate alone.
The phase velocity of the transverse wave to be carried propagates to each piezoelectric substrate alone
It is made of a substance larger than the shear wave phase velocity, and
The interdigital electrode has a frequency substantially corresponding to the electrode period length P.
Of the two-layer structure B
_TSH wave having a wavelength substantially equal to the electrode period length P
And the SH wave is applied to the one surface of the non-piezoelectric plate.
To the two-layer structure part B_RPropagated to the
SH waves are waves of the 0th-order mode and higher-order modes of the 1st and higher order
The phase velocity of the SH wave propagates to the non-piezoelectric plate alone.
Shear wave velocity and shear wave propagating to each piezoelectric substrate alone
It is near the average value of the speed, and the input and output
The interdigital electrode is located on the one surface of the non-piezoelectric plate.
And the part R_iaAnd R_ibUltrasound corresponding to each
Propagation path Z_iaAnd Z_ib(I = 1, 2,..., N)
The output IDT is connected to the one of the non-piezoelectric plates.
When the finger or the object contacts one of the plate surfaces, the ultrasonic wave propagation path
Z_iaAnd Z_ibOne of the Z_XaWhen was cut off
The ultrasonic propagation path Z_XaUltrasonic propagation path Z paired with_Xb
Electrical signal E corresponding to_XbOutput or the non-pressure
The ultrasonic wave propagation path Z contacts the one plate surface of the electric plate_Xb
The ultrasonic propagation path Z only when_XaCompatible with
Electrical signal E_XaIs output. The supersonic of claim 14.
The wave switching element has the intersection width L_QPIs the electrode cycle
The length P is set to the group R_iDivided by twice the number N of
Equal to the product of ecβ. The ultrasonic switch according to claim 15,
The chin element has the intersection width L_BPBefore the electrode cycle length P
Note A_iThe product of the value divided by twice the number N of cos and cosecβ
equal. The ultrasonic switching device according to claim 16.
In the above, each of the piezoelectric substrates is made of a piezoelectric ceramic. Claim 1
7. The ultrasonic switching device according to claim 7, wherein the electric signal E
_i-1And E_{i -2}Each frequency comprises a radio frequency.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first structure of an ultrasonic switching device according to the present invention comprises a piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs. The input and output IDTs are provided on the upper end surface of the piezoelectric substrate, and the lower end surface of the non-piezoelectric plate is fixed to the upper end surface of the piezoelectric substrate via the input and output IDTs. The second structure of the interdigital transducer of the ultrasonic switching element according to the present invention is such that the intersecting region of the electrode fingers of the output interdigital transducer is one group R.
_i (i = 1) or N groups R _i (i
= 1, 2,..., N) and the two groups R _i and R
₍ N-1) parts Q _i ｛i = 1,2,2 sandwiched by _{(i + 1)}
.., (N-1)}. Each group R
_i is two parts R _ia and R _ib, consisting in the portion sandwiched by R _im. The directions of the electrode fingers of the portions R _ia and R _ib are parallel to the direction of the electrode fingers of the input IDT,
The electrode period length of each of the portions R _ia and R _ib is equal to the electrode period length P of the input IDT. The electrode finger of the portion R _im has an angle α with respect to the electrode finger of the input IDT;
The period length P of the electrode finger in the direction orthogonal to the electrode finger of the portion R _im
RN is equal to the product of the electrode period length P and cosα. Part R _{i m}
There are two types of electrode cross widths, _namely , a cross width L _RP of the portion R _im in the direction of the electrode finger and a cross width L _RN of the input IDT in a direction parallel to the electrode finger. L _RP is the intersection width L
_It is equal to the product of _RN and secα and equal to the product of half of the electrode period length P and cosecα. Electrode finger part Q _i has a slope of angle ± beta to the electrode fingers of the input IDT, the period length of the electrode fingers in a direction perpendicular to the electrode fingers of the part Q _i P
_QN is equal to the product of the electrode period length P and cosβ. The electrode cross width portion Q _i, part Q _i overlap length L in the direction of the electrode fingers
And _QP, there are two types of cross width L _QN in the direction parallel to the electrode fingers of the input interdigital transducer, overlap length L _QP is the overlap length L _QN
Equal to the product of secβ. And portions R _{i a} and R _ib respective electrode overlap width, the overlap length L _RN, total overlap length L _QN is approximately equal to the electrode cross width L of the input interdigital transducer. Also,
The intersection width L _QP can take a value equal to a product of a value (P / 2N) obtained by dividing the electrode cycle length P by twice the number N of the groups R _i and cosec β. The second structure of the interdigital transducer of the ultrasonic switching element according to the present invention has a configuration in which the intersecting region of the electrode fingers of the input interdigital transducer has N portions A _i (i =
.., N) and (N−1) parts B _i Ｂi = 1, 2,..., Sandwiched between two parts A _i and A _{(i + 1)}
(N−1)}, and the intersection area of the electrode fingers of the output IDT is (N + 1) parts C _i ｛i = 1,
,..., (N + 1)} and two parts C _i and C
_{(i + 1)} of the N sandwiched portion _{D i (i = 1,2, ......} ,
N). The direction of the electrode finger of the part A _i is parallel to the direction of the electrode finger of the part C _i . The electrode finger portion B _i has an inclination of angle -β with respect to the electrode finger portions A _i, the period length P _BN electrode fingers in a direction perpendicular to the electrode fingers of the portion B _i, part A _i and C _It is equal to the product of the electrode cycle length P of _i and cosβ.
The electrode cross width of the portion B _i, there are two types of the cross width L _BP in the direction of the electrode finger portion B _i, the overlap length L _BN in the direction parallel to the electrode fingers of the portions A _i, crossing The width L _BP is equal to the intersection width L _BN and se
Equal to the product of cβ. Also, the intersection width L _BP is the electrode period length P
Divided by twice the number N of the part A _i (P / 2N), and cos
It is possible to take a value equal to the product with ecβ. Part D
_i electrode fingers of relative electrode finger portions C _i has a slope of angle alpha,
Periodicity P of the electrode fingers in a direction perpendicular to the electrode fingers of the part D _i
DN is equal to the product of the electrode period length P and cosα. The electrode cross width of the portion D _i, part D _i overlap length L in the direction of the electrode fingers
And _DP, there are two types of cross width L _DN in the direction parallel to the electrode fingers of the portions C _i, intersecting width L _DP, as well as equal to the product of the overlap length L _DN and Secarufa, the electrode periodicity P Half and cosecα
Equal to the product of Partial sum of A _i intersection width and overlap length L _BN of the electrode fingers is approximately equal to the sum of the cross width of the electrode finger portions C _i and overlap length L _DN. In the first structure of the ultrasonic switching element according to the present invention, an electric signal having a frequency substantially corresponding to the electrode period length P is input to the input interdigital transducer, so that the electrode period length becomes close to the surface of the upper end surface of the piezoelectric substrate. A surface acoustic wave having a wavelength substantially equal to P can be excited, and the surface acoustic wave can be propagated to the upper end surface of the non-piezoelectric plate.
This surface acoustic wave is a wave of a zero-order mode and a first-order or higher-order mode. The phase velocity of the surface acoustic wave of the zero-order mode is:
The phase velocity of the surface acoustic wave of the first-order or higher-order mode is almost equal to the velocity of the Rayleigh wave propagating to the piezoelectric substrate in an electrically short-circuit state, and propagates to the piezoelectric substrate in an electrically open state. It is almost equal to the speed of Rayleigh waves. A structure in which the thickness d of the piezoelectric substrate is at least three times the electrode period length P and the thickness h of the non-piezoelectric plate is smaller than the electrode period length P is adopted. By using a substance whose phase velocity of the generated surface acoustic wave is smaller than the phase velocity of the surface acoustic wave propagating on the piezoelectric substrate alone, the conversion efficiency between the electric signal and the surface acoustic wave can be improved. Furthermore, by adopting a structure in which the direction of the polarization axis of the piezoelectric substrate is parallel to the direction of its thickness d, it is possible to further improve the conversion efficiency between electric signals and surface acoustic waves. A second structure of the ultrasonic switching element of the present invention includes a piezoelectric substrate for input and output, a non-piezoelectric plate, and IDT electrodes for input and output. The input and output interdigital transducers are provided on one plate surface of each of the input and output piezoelectric substrates, and the input and output piezoelectric substrates are provided on either one of the input and output piezoelectric substrates. And is fixed to the upper end surface of the non-piezoelectric plate. In the second structure of the ultrasonic switching element according to the present invention, an electric signal having a frequency substantially corresponding to the electrode period length P is input to the input interdigital transducer, so that the input piezoelectric substrate is substantially equal to the electrode period length P. It is possible to excite a surface acoustic wave having a wavelength, propagate the surface acoustic wave to the upper end surface of the non-piezoelectric plate, and further propagate the surface acoustic wave to the output piezoelectric substrate from the upper end surface of the non-piezoelectric plate. This surface acoustic wave is a first-order or higher-order mode wave, and its phase speed is substantially equal to the speed of the Rayleigh wave propagating through the non-piezoelectric plate alone. A structure in which the thickness d of each piezoelectric substrate is smaller than the electrode period length P and the thickness h of the non-piezoelectric plate is about three times or more the electrode period length P is adopted. By using a substance whose phase velocity of the surface acoustic wave propagating to the piezoelectric substrate is greater than the phase velocity of the surface acoustic wave propagating to each piezoelectric substrate alone, the conversion efficiency between the electric signal and the surface acoustic wave can be improved. it can. Furthermore, by adopting a structure in which the direction of the polarization axis of each piezoelectric substrate is parallel to the direction of its thickness d, it is possible to further improve the conversion efficiency between electric signals and surface acoustic waves. A third structure of the ultrasonic switching element according to the present invention includes an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs. The input and output interdigital transducers are provided on one plate surface of each of the input and output piezoelectric substrates, and the input and output piezoelectric substrates are provided on either one of the input and output piezoelectric substrates. Is fixed to one of the non-piezoelectric plates. In the third structure of the ultrasonic switching element according to the present invention, an electric signal having a frequency substantially corresponding to the electrode period length P is input to the input interdigital transducer, thereby forming a two-layer structure including the input piezoelectric substrate and the non-piezoelectric plate. Structure B _T
In exciting the acoustic wave having a wavelength substantially equal to the interdigital periodicity P, after propagating the acoustic waves in the non-piezoelectric plate propagates in a two-layer structure B _R consisting output piezoelectric substrate and a non-piezoelectric plate be able to. This elastic wave is a wave of the S ₀ mode and a first-order or higher-order mode, and the phase velocity of the elastic wave is close to zero where the product fd of the frequency f of the elastic wave and the thickness d of each piezoelectric substrate is zero. In this case, the phase velocity V _fd of the elastic wave in the S ₀ mode is substantially equal to ₀ . The thickness d of each piezoelectric substrate is smaller than the electrode period length P, the thickness h of the non-piezoelectric plate is smaller than the thickness d of each piezoelectric substrate, and the direction of the polarization axis of each piezoelectric substrate is the thickness d. By using a material that is parallel to the direction and the phase velocity of the elastic wave propagating to the non-piezoelectric plate alone is larger than the phase velocity of the elastic wave propagating to each piezoelectric substrate alone, the electric signal and the elasticity It is possible to improve the conversion efficiency between waves. Furthermore, by adopting a structure in which the direction of the polarization axis of each piezoelectric substrate is parallel to the direction of its thickness d, it is possible to further improve the conversion efficiency between electric signals and elastic waves. In the third structure of the ultrasonic switching element of the present invention, the following structure can be adopted. That is, the thickness d of each piezoelectric substrate is smaller than the electrode period length P, the thickness h of the non-piezoelectric plate is substantially equal to the thickness d of each piezoelectric substrate, and the direction of the polarization axis of each piezoelectric substrate is A material that is parallel to the direction of the thickness d and that has a phase velocity of an elastic wave propagating through a single non-piezoelectric plate substantially equal to a phase velocity of an elastic wave propagating through a single piezoelectric substrate alone is used as the non-piezoelectric plate. Structure. Also in this structure, it is possible to improve the conversion efficiency between the electric signal and the elastic wave. In the third structure of the ultrasonic switching element of the present invention, the following structure can be adopted. That is, the thickness d of each piezoelectric substrate is smaller than the electrode period length P, and the thickness h of the non-piezoelectric plate is larger than the thickness d of each piezoelectric substrate and smaller than twice the thickness d of each piezoelectric substrate. The direction of the polarization axis of each piezoelectric substrate is determined by its thickness d.
And the phase of the elastic wave propagating to the non-piezoelectric plate alone is smaller than the phase velocity of the elastic wave propagating to each piezoelectric substrate alone. Also in this structure, it is possible to improve the conversion efficiency between the electric signal and the elastic wave. A fourth structure of the ultrasonic switching element according to the present invention includes a piezoelectric substrate for input and output, a non-piezoelectric plate, and IDT electrodes for input and output. The input and output interdigital transducers are provided on one plate surface of each of the input and output piezoelectric substrates, and each of the piezoelectric substrates is connected to the non-piezoelectric plate via the plate surface on which the electrode is not provided. It is fixed to one of the plate surfaces. In the fourth structure of the ultrasonic switching element of the present invention, an electric signal having a frequency substantially corresponding to the electrode period length P is input to the input IDT, so that the two-layer structure _BT has the electrode period length P and exciting the SH wave having a wavelength approximately equal (shear horizontal wave), after propagating the SH wave in the non-piezoelectric plate, can be propagated in a two-layer structure B _R. The SH wave is a transverse wave whose vibration displacement direction is parallel to the upper and lower end surfaces of the piezoelectric substrate. In this manner, by adopting a structure in which the direction of the polarization axis of the piezoelectric substrate is parallel to the direction of the electrode fingers of the input interdigital transducer, the direction of the polarization axis is perpendicular to the electrode fingers of the input interdigital transducer. The SH wave can be efficiently excited. Moreover, if there are at most three pairs of electrode fingers of each interdigital electrode, SH waves can be efficiently excited. SH waves propagating in a two-layer structure B _R is a wave of the zero-order mode and the first-order or higher-order mode, the phase velocity of the SH wave,
The average value of the shear wave speed propagating to the non-piezoelectric plate alone and the average value of the shear wave speed propagating to each piezoelectric substrate alone are provided. The thickness d of each piezoelectric substrate is smaller than the electrode period length P, and the thickness h of the non-piezoelectric plate is substantially equal to or smaller than the thickness d of each piezoelectric substrate. As the non-piezoelectric plate, the interface is in an electrically open state, and as the non-piezoelectric plate, a substance is used whose phase velocity of the transverse wave propagating to the non-piezoelectric plate alone is substantially equal to or less than that of the transverse wave propagating to each piezoelectric substrate alone. This makes it possible to improve the conversion efficiency between the electric signal and the SH wave. A fifth structure of the ultrasonic switching element according to the present invention includes an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs. The input and output interdigital transducers are provided on one plate surface of each of the input and output piezoelectric substrates, and each piezoelectric substrate is connected to one of the non-piezoelectric plates via the plate surface on which the electrode is not provided. Is fixed to the plate surface. In the fifth structure of the ultrasonic switching element of the present invention, an electric signal having a frequency substantially corresponding to the electrode period length P is inputted to the input IDT, so that the two-layer structure _BT has the electrode period length P and exciting the SH wave having a wavelength approximately equal, then the SH waves each piezoelectric substrate of a non-piezoelectric plate were propagated to the plate surface of the person who provided, it can be propagated in a two-layer structure B _R. The SH wave is a wave of a 0th-order mode and a first-order or higher-order mode, and the phase velocity of the SH wave is the average value of the transverse wave velocity propagating to the non-piezoelectric plate alone and the transverse wave velocity propagating to each piezoelectric substrate alone. Near. The thickness d of each piezoelectric substrate is smaller than the electrode cycle length P, the thickness h of the non-piezoelectric plate is larger than the thickness d of each piezoelectric substrate, and smaller than twice the thickness d of each piezoelectric substrate. A substance in which the interface between the piezoelectric substrate and the non-piezoelectric plate is electrically short-circuited, and the phase velocity of the transverse wave propagating to the non-piezoelectric plate alone is greater than the phase velocity of the transverse wave propagating to each piezoelectric substrate alone as a non-piezoelectric plate , It is possible to improve the conversion efficiency between the electric signal and the SH wave. If ultrasonic switching device of the present invention has a first structure of the interdigital electrodes, the ultrasonic wave propagated to the non-piezoelectric plate portion R _ia and R _ib by electrical signals E _ia and E _ib
(I = 1, 2,..., N). The amplitude of the electric signal generated by combining the electric signals E _ia and E _ib becomes zero. This is because the intersection width L _RP is equal to the intersection width L
_This is because it is equal to the product of _RN and secα and equal to the product of half of the electrode period length P and cosecα. The input and output IDTs are formed on the non-piezoelectric plate by a portion R
Ultrasonic propagation paths Z _ia and Z _ib (i = 1, 2,..., N) respectively corresponding to _ia and R _ib are formed. That is,
A group R _i between the input and output IDTs
That is, there are twice as many (2N) ultrasonic propagation paths as the number N. If, when one Z _Xa of the 2N ultrasonic propagation path of non-piezoelectric plate in contact with a human finger or an object is cut off, the ultrasonic propagation path Z _Xb forming the ultrasonic wave propagation path Z _Xa paired electrical signals E _Xb corresponding to is output from the output interdigital transducer. Similarly, when the ultrasonic wave propagation path Z _Xb is cut off, an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa forming a pair with the ultrasonic wave propagation path Z _Xb is output from the output IDT. Thus, the ultrasonic switching element of the present invention can not only generate an electric signal by contacting the non-piezoelectric plate, but also output an electric signal according to the contact position. Therefore, it is possible to fulfill the function as a switch. In the case where the ultrasonic switching element of the present invention has the second structure of the interdigital transducer, the ultrasonic wave propagated to the non-piezoelectric plate is N electric signals E _ia (i = 1, 2,...) By the output interdigital transducer. , N) and N
_Are converted into a plurality of electric signals E _ib (i = 1, 2,..., N). The amplitude of the electric signal generated by combining the electric signals E _ia and E _ib becomes zero. This is because the intersection width L _DP is
This is due to being equal to the product of the intersection width L _DN and secα and equal to the product of half the electrode period length P and cosecα.
In the non-piezoelectric plate, the input and output IDTs are N ultrasonic propagation paths Z _ia (i = 1, 2,..., N).
And N ultrasonic propagation paths Z _ib (i = 1, 2,...,
N). That is, between the input and output interdigital transducer, ultrasonic propagation path of twice the number N of the partial A _i (2N pieces) will be present. If a finger or an object comes into contact with the non-piezoelectric plate, one of 2N ultrasonic propagation paths
One When Z _Xa is interrupted, an electric signal E _Xb corresponding to the ultrasonic propagation path Z _Xb forming the ultrasonic wave propagation path Z _Xa and pair is outputted from the output interdigital transducer. Similarly, the ultrasonic wave propagation path Z _Xb
Is cut off, an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa paired with the ultrasonic wave propagation path Z _Xb is output from the output IDT. In this manner, the ultrasonic switching element of the present invention can generate an electric signal by contacting the non-piezoelectric plate, and can output an electric signal according to the contacted position. Therefore,
It becomes possible to fulfill the function as a switch. In the ultrasonic switching element of the present invention, a device excellent in design easiness can be provided by adopting a structure in which each piezoelectric substrate is made of piezoelectric ceramic. In the ultrasonic switching element of the present invention, the electric signals E _i-1 and E
By employing a structure in which each frequency of _i-2 is a radio frequency, it becomes possible to radiate the electric signal E _i-1 or E _{i -2} as a radio signal.

FIG. 1 is a sectional view of an ultrasonic switching device according to the present invention.
It is sectional drawing which shows Example of one. This embodiment is a piezoelectric substrate
1, non-piezoelectric plate 2, input IDT 3, and output ID
It consists of a drooping electrode 4. IDTs 3 and 4 are Al
It is made of a thin film of minium and has 10 pairs of electrode fingers.
1 is provided on the upper end surface. The thickness d of the piezoelectric substrate 1 is
It is made of 1.5mm piezoelectric ceramic, and its polarization axis direction
Is parallel to the direction of the thickness d. Non-piezoelectric plate 2 is made of glass
Other materials such as fluororesin, acrylic resin or plastic
It is made of a polymer compound and its thickness h is 150 μm.
The upper end surface of the piezoelectric substrate 1 is interposed with interdigital electrodes 3 and 4.
And a non-piezoelectric plate 2 is provided. Non-piezoelectric plate 2 is made of glass, etc.
In the case of consisting of:
Is fixed, and the non-piezoelectric plate 2 is made of fluororesin or acrylic resin.
The non-piezoelectric plate 2 is applied directly on the piezoelectric substrate 1
ing. FIG. 2 is a plan view of the ultrasonic switching device of FIG.
It is. However, in FIG. 2, the piezoelectric substrate 1, the interdigital electrodes 3 and
And only 4 are depicted. The IDT 3 is a regular type
Having an electrode period length P of 400 μm and an electrode cross width L
Is 15 mm. Intersection area of electrode fingers of IDT 4
Is one group R₁Group R₁Is two
Part R_1aAnd R_1bAnd the portion R sandwiched between them_1mConsisting of
You. Part R_1aAnd R_1bDirection of each electrode finger
The part R is parallel to the direction of the electrode fingers of the_1aAnd R
_1bEach electrode cycle length is the electrode cycle length of the IDT 3
Equal to P. FIG. 3 shows the portion R_1mFIG. part
R_1mIs inclined at an angle α with respect to the electrode fingers of the interdigital electrode 3.
And the part R_1mElectrode finger in a direction perpendicular to the electrode finger
Period length P_RNIs equal to the product of the electrode period length P and cosα.
No. Part R_1mThe electrode intersection width of_1mElectrode fingers
Intersection width L in the direction_RPAnd parallel to the electrode fingers of the IDT 3
Intersection width L in direction_RNThere are two types. Intersection width L_RPIs
Intersection width L_RNIs equal to the product of
It is equal to the product of half the length P and cosecα. Note that the part R_1a
And R_1bEach electrode cross width (7 mm) and the part R
_1mIntersection width L_RN(1 mm) is the sum of the IDTs 3
It is equal to the electrode intersection width L (15 mm). FIG. 4 is the supersonic of FIG.
FIG. 3 is a circuit configuration diagram of a wave switching element. IDT electrodes
4 is connected to the amplifier AMP. IDT electrodes
When an electric signal is input from the piezoelectric substrate 1, the upper surface of the piezoelectric substrate 1 is displayed.
A surface acoustic wave is generated at a portion in contact with the IDT 3 near the surface.
Excited. This surface acoustic wave is transmitted to the upper end surface of the non-piezoelectric plate 2.
After being conveyed, the upper surface of the piezoelectric substrate 1 has an interdigital shape near the surface.
The light is propagated to the portion in contact with the electrode 4 and the portion R_1aAnd R_1b
The electric signal E_1aAnd E_1bAre converted to
You. At this time, the electric signal E_1aAnd E_1bSynthesizing
Causes the amplitude of the electric signal to be zero. IDT electrodes
3 and 4 are portions R on the upper end surface of the non-piezoelectric plate 2._1a
And R_1bUltrasonic propagation path Z corresponding to each_1aand
Z_1bTo form If the upper end surface of the non-piezoelectric plate 2 is
Or an object comes into contact with the_1bBut
When cut off, the ultrasonic wave propagation path Z_1aElectrical signal E corresponding to
_1aIt is output from the interdigital electrode 4. Similarly, supersonic
Wave propagation path Z_1aIs interrupted, the electric signal E_1bIs output
You. That is, the upper end surface of the non-piezoelectric plate 2 is brought into contact with the
Carriage Z_1aOr Z_1bBy cutting off, the cut off super
Electric signal E corresponding to sound wave propagation path_1bOr E_1aRaises
The ultrasonic switching of the present invention
The element can function as a switch.
You. Further, the electric signal E_1aOr E_1bHas radio frequency
By adopting such a structure, the electric signal E_1aOr E
_1bCan be radiated as a wireless signal. Blinds
Signal E output from the electrode 4_1aOr E_1bIs amplified
Of the electric signal amplified by the amplifier AMP
The data is input to the interdigital electrode 3 again. In this way,
Ultrasonic wave propagation path Z_1aOr Z_1bOscillator with delay element
Configuration makes it possible to drive with low power consumption
In addition, the circuit configuration is simplified. FIG. 5 shows the piezoelectric substrate 1
Calculated from phase velocity difference under two different electrical boundary conditions
Electromechanical coupling coefficient k^TwoAnd the wave number k of the surface acoustic wave
Characteristic diagram showing the relationship between the thickness h of the piezoelectric plate 2 and the product (kh)
It is. However, in FIG. 5, the non-piezoelectric plate 2 is made of a glass plate.
Of the surface acoustic wave propagating through the glass plate
Degree is 2297 m / s and longitudinal wave speed is 4156 m / s
FIG. This shear wave velocity 2297m /
s and longitudinal wave velocity of 4156 m / s
1340 m / s shear wave velocity and longitudinal wave velocity
It is almost 0.9 times each of 4390 m / s. In FIG.
The electric energy applied to the interdigital transducer 3 is
Is most efficiently converted to a zero-order mode surface acoustic wave.
Conversion tends to be difficult as the next mode is entered
You can see that. Electric energy applied to the interdigital electrode 3
Lugie is most easily converted to a zero-order mode surface acoustic wave
Is when the kh value is about 1.6,^TwoIs the maximum value
Of about 15.5%. Where k^TwoThe value is the surface acoustic wave
LiNbO in practical use as a piezoelectric substrate for_ThreeSingle crystal
It is worthy of evaluation even if it is about 5%
Is evident. FIG. 6 shows a state where light propagates near the surface of the piezoelectric substrate 1.
FIG. 5 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave,
It is a figure showing the phase velocity of each mode to a value. However,
In FIG. 6, the non-piezoelectric plate 2 is a glass plate of the same material as in FIG.
A characteristic diagram is shown in the case of the following. In higher order modes
Has a cutoff frequency. ● The mark is an interdigital electrode
Electric energy applied to 3 is the elastic surface of each mode
Kh value that is most efficiently converted to waves (calculated from FIG. 5)
By value, k^TwoIndicates the maximum value (kh value). 0th mode
The phase velocity (approximately 2170 m / s) at
Piezoelectric substrate when the surface of substrate 1 is electrically short-circuited
One Rayleigh wave velocity (2150m / s)
No. The phase velocities of the first and higher order modes at
Constant (about 2370 m / s), the surface of the piezoelectric substrate 1 alone
When the piezoelectric substrate 1 is in the electrically open state
It is almost equal to the Lie wave velocity (2340 m / s). Figure 7 shows the pressure
Phase velocity of the circuit board 1 under two different electrical boundary conditions
K calculated from the difference^TwoCharacteristic diagram showing the relationship between the value and the kh value
It is. However, in FIG. 7, the non-piezoelectric plate 2 is made of a glass plate.
Of the surface acoustic wave propagating through the glass plate
Degree is 1988m / s and longitudinal wave speed is 3597m / s
FIG. This transverse wave velocity 1988m /
s and the longitudinal wave velocity of 3597 m / s
1340 m / s shear wave velocity and longitudinal wave velocity
It is approximately 0.8 times each of 4390 m / s. In FIG.
The electric energy applied to the interdigital transducer 3 is
Is most efficiently converted to a zero-order mode surface acoustic wave.
Conversion tends to be difficult as the next mode is entered
You can see that. Electric energy applied to the interdigital electrode 3
Lugie is most easily converted to a zero-order mode surface acoustic wave
Is when the kh value is about 1.6,^TwoIs the maximum value
Of about 18.5%. FIG. 8 shows the vicinity of the surface of the piezoelectric substrate 1.
FIG. 9 is a characteristic diagram showing a velocity dispersion curve of a propagating surface acoustic wave.
FIG. 3 is a diagram showing the phase velocity of each mode with respect to the kh value.
You. However, in FIG. 8, the non-piezoelectric plate 2 is made of the same material as in FIG.
A characteristic diagram in the case of a glass plate is shown. Higher than primary
In the next mode, there is a cutoff frequency. ● mark
The electric energy applied to the drooping electrode 3 varies in each mode.
Kh value that is most efficiently converted to surface acoustic waves (see FIG. 7
The value calculated from^TwoIndicates the maximum value (kh value).
The phase velocity at the ● mark of the 0th-order mode (about 2095 m /
s) is the phase of the zero-order mode shown in FIG.
Speed (about 2170 m / s), but the piezoelectric substrate 1
Piezoelectric substrate 1 when the surface of a single body is in an electrically shorted state
It is almost equal to the Rayleigh wave velocity (2150m / s) of a single substance
No. The phase velocities of the first and higher order modes at
6 (approximately 2300 m / s)
The phase velocity (about 2370 m)
/ S), but the surface of the piezoelectric substrate 1 alone is electrically
Wave velocity of the piezoelectric substrate 1 when it is in the open state
Degree (2340 m / s). According to FIGS.
The surface acoustic wave propagated to the piezoelectric plate 2 has the 0th mode and the 1st mode.
A higher order mode wave than the next order,
The electrical energy is
Phase velocities that are also easily converted, are electrically short-circuited
It is almost equal to the speed of Rayleigh wave propagating on the piezoelectric substrate 1 alone.
No. Also, the electric energy applied to the IDT 3
Is converted most to first-order or higher order surface acoustic waves.
The easy phase speed is achieved by the piezoelectric substrate 1 in an electrically open state.
It is almost equal to the speed of the Rayleigh wave propagating to a single substance. Further
The transverse wave of the surface acoustic wave propagating through the non-piezoelectric plate 2 alone and
The lower the velocity of the longitudinal wave, the more the piezoelectric substrate 1
The phase velocity of each mode of the propagated surface acoustic wave decreases.
You. Similarly, a surface acoustic wave is generated at the IDT 4
When converted to an electrical signal, especially the elasticity of the 0th mode
Surface waves are efficiently converted to electrical signals,
Understand that there is a tendency that conversion tends to be difficult as
You. Zero-order mode surface acoustic waves are efficiently converted to electrical signals
What is done is the phase velocity of the zero-order mode surface acoustic wave.
Propagates to the piezoelectric substrate 1 in an electrically short-circuited state.
When the speed is almost equal to the Rayleigh wave speed,
Higher-order surface acoustic waves are efficiently converted to electrical signals
Is the phase of the surface acoustic wave in the first or higher order mode.
Velocity propagates to the piezoelectric substrate 1 that is electrically open
This is the case when the speed is almost equal to the speed of the Rayleigh wave. Also,
Transverse and longitudinal waves of surface acoustic waves propagating through non-piezoelectric plate 2 alone
The lower the speed, the more the propagation from the non-piezoelectric plate 2 to the piezoelectric substrate 1
The phase velocity of each mode of the generated surface acoustic wave becomes small.
FIG. 9 shows a second embodiment of the ultrasonic switching device according to the present invention.
FIG. This embodiment is different from the first embodiment in FIG.
The output IDT 4 is replaced with the output IDT 5
It has a curved structure. In FIG. 9, the piezoelectric substrate 1 and the
Only poles 3 and 5 are depicted. Electricity of the interdigital electrode 5
The intersection area of the extreme fingers is composed of two groups R₁And R_TwoAnd one
Part Q₁And the part Q₁Is the group R₁And R_Twoof
between. Group R₁Is the two parts R_1aAnd R_1bWhen
Part R sandwiched between them_1mGroup R_TwoIs 2
One part R_2aAnd R_2bAnd the portion R sandwiched between them_2mOr
Consisting of Part R_1a, R_1b, R_2aAnd R_2bEach
The direction of the pole finger is parallel to the direction of the electrode finger of the interdigital electrode 3,
Part R_1a, R_1b, R_2aAnd R_2bEach electrode cycle length
It is equal to the electrode period length P of the interdigital transducer 3. Part R_1mYou
And R_2mIs similar to the structure shown in FIG.
You. FIG.₁FIG. Part Q₁No electricity
The pole finger has a slope of an angle -β with respect to the electrode finger of the interdigital electrode 3.
I do. In the present embodiment, the inclination of −β is thus obtained.
Has a slope of + β. Part Q₁of
Period length P of the electrode finger in the direction perpendicular to the electrode finger_QNIs the electrode
It is equal to the product of the period length P and cosβ. Part Q₁Electrode intersection width
Has part Q₁Width L in the direction of the electrode finger_QPAnd Sumada
Intersection width L in the direction parallel to the electrode fingers of the spiral electrode 3_QNWith 2
There are types. Intersection width L_QPIs the intersection width L_QNAnd secβ
And the value obtained by dividing the electrode cycle length P by 4 (P /
4) is equal to the product of cosecβ. Note that the part R_1a,
R_1b, R_2aAnd R_2bEach electrode cross width (3mm)
And the part R_1mAnd R_2mEach intersection width L_RN(1m
m) and part Q₁Intersection width L_QN(1mm)
It is equal to the electrode cross width L (15 mm) of the interdigital electrode 3. No.
When driving the ultrasonic switching element of the second embodiment,
The circuit configuration of FIG. 4 is used. However, the interdigital transducer shown in FIG.
The pole 4 is replaced by an interdigital electrode 5. IDT electrodes
3, the upper end of the piezoelectric substrate 1
Excited in the area near the IDT 3 near the surface
Surface acoustic waves propagated to the upper end surface of the non-piezoelectric plate 2
Thereafter, the interdigital transducer 5 near the upper end surface of the piezoelectric substrate 1
Propagated to the contacting part, the part R_1a, R_1b, R_2aand
R_2bThe electric signal E_1a, E_1b, E_2aAnd E_2bNiso
Each is converted. Electric signal E_1aAnd E_1bCompose
The resulting amplitude of the electrical signal and the electrical signal E_2aYou
And E_2bThe amplitude of the electric signal generated by combining
Both become zero. The IDTs 3 and 5 are non-piezoelectric plates
2 at the upper end face_1a, R_1b, R_2aAnd R_2b
Ultrasonic propagation path Z corresponding to each_1a, Z_1b, Z_2aAnd
And Z_2bTo form If the upper end surface of the non-piezoelectric plate 2 is
Or, when an object comes into contact with the_1b
Is interrupted, the ultrasonic wave propagation path Z_1aElectrical signal corresponding to
E_1aThe output from the interdigital transducer 5 is likewise supersonic.
Wave propagation path Z_1aIs interrupted, the electric signal E_1bIs output,
Ultrasonic wave propagation path Z_2aIs interrupted, the electric signal E_2bIs output
The ultrasonic propagation path Z_2bIs interrupted, the electric signal E_2aComes out
Is forced. That is, the upper surface of the non-piezoelectric plate 2 is brought into contact with the
Sound propagation path Z_1a, Z_1b, Z_2aOr Z_2bTo block
The electrical signal E_1b, E_1a, E_2bOr E_2aOccurs
The ultrasonic switch of the present invention
The switching element functions as a switch. In addition, electricity
Signal E_1a, E_1b, E_2aOr E_2bHas radio frequency
By adopting the structure, the electric signal E_1a, E_1b, E_2a
Or E_2bCan be radiated as a wireless signal.
You. Electric signal E output from the interdigital transducer 5_1a,
E_1b, E_2aOr E_2bIs amplified by the amplifier AMP
A part of the amplified electric signal is applied to the IDT 3 again.
Is entered. Thus, the ultrasonic wave propagation path Z_1a,
Z_1b, Z_2aOr Z_2bAn oscillator with a delay element
It is. FIG. 11 shows a third embodiment of the ultrasonic switching device according to the present invention.
It is a top view which shows the Example of FIG. This embodiment is the first embodiment of FIG.
The input IDT and the output IDT of the embodiment
Pole 4 has IDT 6 for input and IDT for output
7 has the same structure as that of FIG. In FIG. 11, the piezoelectric substrate
1, only the interdigital electrodes 6 and 7 are shown. Suda
The intersecting region of the electrode fingers of the reed-shaped electrode 6 has two portions A₁And
And A_TwoAnd one part B₁And part B₁Is part A₁And
And A_TwoBetween. In addition, the electrode fingers of the IDT 7
The difference area has three parts C₁, C_TwoAnd C_ThreeAnd two parts
Minute D₁And D_TwoAnd part D₁Is part C₁And C_Two
Part D_TwoIs part C_TwoAnd C_ThreeBetween.
Part A₁And A_TwoThe direction of each electrode finger is
C₁, C_TwoAnd C_ThreeParallel to the direction of each electrode finger
You. Part A₁, A_Two, C₁, C_TwoAnd C_ThreeEach electrode
The cycle length P is 400 μm. FIG. 12 shows part B₁Expansion
It is a top view. Part B₁Electrode finger is part A₁And A_Twoof
Part B having an angle of -β with respect to the electrode finger₁On the electrode finger
Period length P of electrode finger in orthogonal direction_BNIs the electrode cycle length P
And cosβ. Part B₁The electrode intersection width
Minute B₁Width L in the direction of the electrode finger_BPAnd part A₁and
A_TwoWidth L in the direction parallel to the electrode finger_BNAnd two types
is there. Intersection width L_BPIs the intersection width L_BNEqual to the product of
No. Further, the intersection width L_BPIs obtained by dividing the electrode cycle length P by 4.
It is equal to the product of the value (P / 4) and cosecβ. FIG. 13 is a part
D₁FIG. Part D_TwoPart D₁The same structure as
Make up. Part D₁Electrode finger is part C₁, C_TwoAnd C_Threeof
Part D has an inclination of angle α with respect to the electrode finger.₁Directly to the electrode finger
Period length P of the electrode finger in the intersecting direction_DNIs the electrode period length P and
Equal to the product of cosα. Part D₁The electrode intersection width
D₁Width L in the direction of the electrode finger_DPAnd part C₁, C_TwoYou
And C_ThreeWidth L in the direction parallel to the electrode finger_DNAnd two kinds
There is kind. Intersection width L_DPIs the intersection width L_DNAnd the product of secα
Equal to the product of half of the electrode period length P and cosec α
be equivalent to. Part D_TwoThe same applies to. Part A₁And
And A_TwoEach electrode cross width (7 mm) and part B₁Exchange
Difference width L_BNThe total (15 mm) of (1 mm) is₁You
And C_ThreeEach electrode cross width (3 mm) and the part C_Twoof
Electrode cross width (7mm) and part D₁And D_Twoeach
Intersection width L_{D N}Equivalent to the sum of (1 mm) (15 mm). No.
When driving the ultrasonic switching element of the third embodiment,
The circuit configuration of FIG. 4 is used. However, the interdigital transducer shown in FIG.
Poles 3 and 4 are replaced by interdigital electrodes 6 and 7
You. By inputting an electric signal from the interdigital transducer 6
Contact with the IDT 6 near the upper surface of the piezoelectric substrate 1
The surface acoustic wave excited in the part to be
After being propagated to the surface, the space near the upper end surface of the piezoelectric substrate 1
Propagated to the portion in contact with the interdigital electrode 7, the interdigital electrode
7, two electric signals E_1aAnd E_2aAnd two
Air signal E_1bAnd E_2bIs converted to Electric signal E_1aAnd
And E_1bThe amplitude of the electric signal generated by combining
And the electric signal E_2aAnd E_2bBy synthesizing
The resulting amplitude of the electrical signal is zero. Interdigital electrodes 6 and
And 7 at the upper end surface of the non-piezoelectric plate 2
Carriage Z_1aAnd Z_2aAnd two ultrasonic propagation paths Z_1band
Z_2bTo form Ultrasonic wave propagation path Z_1aIs part A₁And C₁With
In between, the ultrasonic propagation path Z_1bIs part A₁And C_TwoBetween the super sound
Wave propagation path Z_2aIs part A_TwoAnd C_TwoBetween the ultrasonic propagation path Z
_2bIs part A_TwoAnd C_ThreeExists between If,
The upper end surface of the non-piezoelectric plate 2 is
Of the ultrasonic propagation paths of Z_1bIs interrupted, the ultrasonic propagation
Road Z_1aElectrical signal E corresponding to _1aExit from the blind electrode 7
Is forced. Similarly, the ultrasonic wave propagation path Z_1aIs shut off
And the electric signal E_1bIs output, and the ultrasonic wave propagation path Z_2aCut off
The electric signal E_2bIs output, and the ultrasonic wave propagation path Z_2b
Is interrupted, the electric signal E_2aIs output. This and
The ultrasonic propagation path Z_1a, Z_1b, Z_2aOr Z_2bIs cut off
Part D₁And D_TwoConvert with
No electrical signal is output. Like this
Then, the upper end surface of the non-piezoelectric plate 2 is brought into contact with the_1a,
Z_1b, Z_2aOr Z_2bBy shutting off the electrical signal
E_1b, E_1a, E_2bOr E_2aCan cause each
Therefore, the ultrasonic switching element of the present invention
It becomes possible to fulfill the function as a switch. Further
And the electric signal E_1a, E_1b, E_2aOr E_2bIs radio frequency
By adopting the structure having_1a, E
_1b, E_2aOr E_2bCan be radiated as wireless signals
It works. Electric signal output from IDT 7
E_1a, E_1b, E_2aOr E_2bIs increased by the amplifier AMP.
A part of the amplified and amplified electric signal is applied to the interdigital electrode 6.
Will be entered again. Thus, the ultrasonic wave propagation path Z_1a,
Z_1b, Z_2aOr Z_2bAn oscillator with a delay element
It is. FIG. 14 shows a fourth embodiment of the ultrasonic switching device of the present invention.
It is sectional drawing which shows Example of (a). This embodiment uses a piezoelectric substrate for input.
Plate 8, output piezoelectric substrate 9, non-piezoelectric plate 10, IDT
Consists of 3 and 4. The interdigital electrodes 3 and 4 are piezoelectric
Plates 8 and 9 are provided on the respective upper end surfaces. Piezoelectric
Substrates 8 and 9 have a thickness d of 150 μm and a polarization axis
The direction is parallel to the direction of the thickness d. Non-piezoelectric plate 10 is thick
h is 1.5 mm. The piezoelectric substrates 8 and 9 are non-piezoelectric plates
10 is fixed to the upper end surface. The blinds in FIG.
The relative structure between the electrodes 3 and 4 is shown in FIG.
The relative structure between the interdigital electrodes 3 and 4 is the same. Book
When using the ultrasonic switching element of the embodiment,
The upper end surface of the electric plate 10 is brought into contact. Ultrasonic wave of the fourth embodiment
When driving the switching element, the circuit configuration of FIG.
Can be When an electric signal is input from the interdigital electrode 3, the pressure
A surface acoustic wave is excited on the circuit board 8. This surface acoustic wave
Is propagated to the upper end surface of the non-piezoelectric plate 10 and then
And the part R_1aAnd R_1bThe electric signal E_1a
And E_1bRespectively. Interdigital electrodes 3 and
And 4 at the upper end face of the non-piezoelectric plate 10_1aAnd
And R_1bUltrasonic propagation path Z corresponding to each_1aAnd Z_1b
To form The ultrasonic switching element of the fourth embodiment is also
Also, it performs an effective function as a switch. Figure 15 shows piezoelectric
Position of the substrate 8 or 9 under two different electrical boundary conditions
K calculated from phase velocity difference^TwoAnd the frequency f of the surface acoustic wave
(Fd) between the thickness of the piezoelectric substrate 8 or 9 and the thickness d of the piezoelectric substrate 8 or 9
FIG. However, in FIG. 15, the non-piezoelectric plate 10
Is the speed of the transverse wave of the surface acoustic wave propagating through the non-piezoelectric plate 10 alone.
Degree is 3091m / s and longitudinal wave speed is 5592m / s
A characteristic diagram in the case of using such a material is shown. This horizontal wave
3091m / s velocity and 5592m / s longitudinal wave velocity
Is the transverse wave velocity 24 for the piezoelectric substrate 8 or 9 alone.
50 m / s and longitudinal wave velocity of 4390 m / s
It is about 1.3 times. In FIG. 15, in addition to the interdigital electrodes 3,
The electrical energy is particularly the first-order surface acoustic wave
It can be seen that the conversion is made most efficiently. IDT electrodes
Table 3 shows the elasticity of the first-order mode
The fd value of about 1.3 MHz is most easily converted to a surface wave.
Mm, then k^TwoIs about 4.7% of the maximum
Show. FIG. 16 shows an elastic surface propagating on the piezoelectric substrate 8 or 9
FIG. 4 is a characteristic diagram illustrating a velocity dispersion curve of a wave, with respect to an fd value.
It is a figure showing the phase velocity of each mode. However, in FIG.
Is a characteristic when the non-piezoelectric plate 10 is made of the same material as that of FIG.
A gender diagram is shown. ● mark is added to the IDT 3
Electric energy is most efficient for surface acoustic waves in each mode
Fd value (value calculated from FIG. 15,^TwoBut
Fd value indicating the maximum value). Of higher order modes
● Phase speed at the mark is almost constant (about 2980 m / s)
, The Rayleigh wave velocity propagating to the non-piezoelectric plate 10 alone (28
50 m / s). FIG. 17 shows the piezoelectric substrate 8 or
From the phase velocity difference under 9 different electrical boundary conditions
Calculated k^TwoFIG. 4 is a characteristic diagram showing a relationship between the value and the fd value.
You. However, in FIG. 17, the non-piezoelectric plate 10
The speed of the transverse wave of the surface acoustic wave propagating on a single body is 4203 m /
s and a material whose longitudinal wave velocity is 7604 m / s.
FIG. This shear wave speed 4203m /
s and longitudinal wave velocity of 7604 m / s
Shear wave velocity of 2450 m / s for 8 or 9 alone and
It is almost 1.7 times each of longitudinal wave speed 4390m / s
You. In FIG. 17, the electric energy applied to the IDT 3 is shown.
Energy is most efficient especially for first-order surface acoustic waves.
It can be seen that it is converted. Applied to the interdigital electrode 3
Electric energy is converted most to first-order surface acoustic wave
Is likely to occur when the fd value is about 0.7 MHz · mm
In this case, k^TwoIndicates about 14.0% of the maximum value. FIG.
8 is the velocity component of the surface acoustic wave propagating through the piezoelectric substrate 8 or 9
FIG. 10 is a characteristic diagram showing a scatter curve, and shows the relationship between the fd value and each mode.
It is a figure showing a phase velocity. However, in FIG. 18, the non-piezoelectric plate
FIG. 10 is a characteristic diagram when 10 is made of the same material as FIG.
You. ● indicates the electric energy applied to the IDT 3
Energy is most efficiently converted to surface acoustic waves in each mode
fd value (the value calculated from FIG. 17 and k^TwoIndicates the maximum value
fd value). For the higher-order modes of the first or higher order
The phase velocity is almost constant (about 3800 m / s) and the non-piezoelectric plate
Rayleigh wave velocity (3860 m / s) propagating to 10 single substance
Is almost equal to 15 to 18, the efficiency of the non-piezoelectric plate 10 is improved.
A well-propagated surface acoustic wave is a higher-order mode or higher order wave
It turns out that it is. Also added to the interdigital electrode 3
Surface of higher order mode whose electric energy is higher than 1st order
The phase velocity that is most easily converted to waves is the non-piezoelectric plate 10 alone
Is almost equal to the Rayleigh wave velocity propagating in Similarly,
Elastic table of higher order modes of IDT 4
When a surface wave is converted to an electrical signal, the order of the surface acoustic wave
Rayleigh wave velocity at which the phase velocity propagates to the non-piezoelectric plate 10 alone
When they are almost equal, they are efficiently converted into electric signals. FIG.
In the ultrasonic switching element No. 4, the interdigital electrodes 4
It is possible to have a structure that replaces the interdigital electrode 5.
In addition, the interdigital electrodes 3 and 4 are
Is possible. FIG.
FIG. 14 is a cross-sectional view illustrating a fifth embodiment of the sound wave switching element.
You. In this embodiment, an input piezoelectric substrate 11 and an output piezoelectric substrate 1 are used.
2. Non-piezoelectric plate 13, input IDT 14 and output
It consists of an interdigital electrode 15. IDT 14 and
15 is provided on the lower end surface of each of the piezoelectric substrates 11 and 12
Have been. The thickness d of the piezoelectric substrates 11 and 12 is 1 mm
The direction of the polarization axis is parallel to the direction of the thickness d. Non
The thickness h of the piezoelectric plate 13 is 150 μm. Piezoelectric substrate 11
And 12 are fixed to the lower end surface of the non-piezoelectric plate 13.
The piezoelectric substrate 11 and the non-piezoelectric plate 13 have a two-layer structure B_TForm
The piezoelectric substrate 12 and the non-piezoelectric plate 13 are_RThe shape
To achieve. Between the interdigital transducers 14 and 15 in FIG.
Is the structure of the interdigital transducers 3 and 4 shown in FIG.
It is the same as the relative structure between them. Electrodes of IDT 14
The cycle length P is 1.6 mm, and the electrode intersection width L is 15 mm.
You. When using the ultrasonic switching element of this embodiment
Contact the upper or lower end of the non-piezoelectric plate 13
May be. The ultrasonic switching element of the fifth embodiment
When driving, the circuit configuration of FIG. 4 is used. However,
4 interdigital electrodes 3 and 4 are interdigital electrodes 14 and
Replaced with 15. Electric signal from IDT 14
Is input, the two-layer structure B_TAn elastic wave is excited.
The elastic wave propagates through the non-piezoelectric plate 13 and has a two-layer structure.
Structure B_RTo the part R_1aAnd R_1bBy
Air signal E_1aAnd E_1bRespectively. Blinds
The electrodes 14 and 15 are formed on the non-piezoelectric plate 13 by the portions R
_1aAnd R_1bUltrasonic propagation path Z corresponding to each_1aAnd
And Z_1bTo form Ultrasonic switching of the fifth embodiment
The element also performs an effective function as a switch. FIG.
Is the two-layer structure part B in FIG._TOf the piezoelectric substrate 11
Calculated from the phase velocity difference under two electrical boundary conditions
k^TwoValue, the frequency f of the elastic wave and the thickness d of the piezoelectric substrate 11
FIG. 6 is a characteristic diagram showing a relationship with a product (fd) of. However, FIG.
At 0, the non-piezoelectric plate 13 propagates through the non-piezoelectric plate 13 alone
The velocity of the shear wave is 4203 m / s and the velocity of the longitudinal wave is 7
The characteristic diagram for the case where the material is 604 m / s is shown.
Is done. This shear wave velocity of 4203 m / s and longitudinal wave velocity of 7
The value of 604 m / s is the horizontal value of the piezoelectric substrate 11 alone.
Wave velocity 2450 m / s and longitudinal wave velocity 4390 m / s
It is almost 1.7 times each. In FIG. 20, A₀Mode of
k^TwoOnly the values are always below 5%. Therefore, A₀Mo
Mode, except S₀Mode and primary (A₁And
And S₁) Efficient higher-order elastic waves are efficiently two-layered
Part B_TIt can be seen that it is excited. For the interdigital electrode 14
The applied electric energy is, for example, A_TwoMode of
The fd value of about 3.8 MH is most easily converted to elastic waves.
z · mm, then k^TwoThe value is about 1 of the maximum
Reaches 4%. FIG. 21 shows a two-layer structure part B of FIG._TPropagate
FIG. 5 is a characteristic diagram showing a velocity dispersion curve of an elastic wave, and fd value;
FIG. 9 is a diagram showing the phase speed of each mode with respect to FIG. However,
At 21, the non-piezoelectric plate 13 is made of the same material as that of FIG.
A characteristic diagram for the case is shown. The mark ● is added to the IDT electrode 14.
The obtained electrical energy is most effective for the elastic wave of each mode.
The fd value that is efficiently converted (the value calculated from FIG.
^TwoIndicates the maximum value (fd value). In FIG. 21, the fd value is
S when near zero₀Mode velocity V of elastic wave
_{fd = 0}Is about 3750 m / s. ● Phase speed at mark
Is almost V_{fd = 0}It turns out that it is equal to a value. Like this
And the two-layer structure B_TVelocity and V of elastic wave excited by
_{fd = 0}Fd value when the value almost matches k^TwoThe maximum value of
It turns out to bring. FIG. 22 shows an ultrasonic switch of the present invention.
It is sectional drawing which shows 6th Example of a chin element. This implementation
As an example, the non-piezoelectric plate 13 of the fifth embodiment shown in FIG.
9 is replaced by the same structure. The non-piezoelectric plate 19 has a thickness h
Is 1 mm. The piezoelectric substrate 11 and the non-piezoelectric plate 19 have a two-layer structure.
Structure B_TIs formed, and the piezoelectric substrate 12 and the non-piezoelectric plate 19 have two layers.
Structure B_RTo form Ultrasonic switching of this embodiment
When an element is used, the upper end or lower end of the non-piezoelectric plate 19
Either of the surfaces may be in contact. The ultrasonic switch of the sixth embodiment
The switching element also functions effectively as a switch
You. FIG. 23 shows a two-layer structure part B of FIG._TPiezoelectric substrate in
Phase velocity difference under eleven different electrical boundary conditions?
K calculated from^TwoFIG. 4 is a characteristic diagram showing a relationship between the value and the fd value.
You. However, in FIG. 22, the non-piezoelectric plate 19 is
When the velocity of the transverse wave of an elastic wave propagating through a single body is 2297 m / s
A field made of a material whose longitudinal wave velocity is 4155 m / s
A characteristic diagram for the case is shown. This shear wave velocity 2297m / s
And the value of the longitudinal wave velocity of 4155 m / s
Shear wave velocity 2450 m / s and longitudinal wave velocity 4 when used alone
390 m / s. In FIG. 23, A₀Mo
K^TwoOnly the values are always below 5%. Therefore,
A₀Mode except mode, that is, S₀Mode and primary
(A₁And S₁) Efficient elastic waves of higher modes
Two-layer structure B_TIt can be seen that it is excited. IDT
The electrical energy applied to pole 14 is, for example, S₁
The fd value is the most easily converted to the elastic wave of the mode
1.8 MHz mm, where k^TwoThe value is
It reaches about 9.5% of the maximum value. FIG. 24 shows the two-layer structure of FIG.
Part B_TCharacteristic diagram showing the velocity dispersion curve of an elastic wave propagating through
FIG. 7 is a diagram showing the phase velocity of each mode with respect to the fd value.
You. However, in FIG. 24, the non-piezoelectric plate 19 is similar to that in FIG.
A characteristic diagram in the case of a material is shown. ● The sign is a blind
The electric energy applied to the electrode 14 is the
Fd value that is most efficiently converted to a natural wave (calculated from FIG. 23)
With the value^TwoIndicates the maximum value (fd value). FIG.
Then V_{fd = 0}The value is about 3670 m / s. ● In the seal
Phase velocity is almost V_{fd = 0}It turns out that it is equal to a value. This
Thus, the two-layer structure B_TVelocity of elastic wave excited in
Degree and V_{fd = 0}Fd value when the value almost matches k^TwoMost
It turns out that it brings a large value. FIG. 25 shows an ultrasonic wave according to the present invention.
FIG. 14 is a sectional view showing a seventh embodiment of the switching element.
In this embodiment, the non-piezoelectric plate 13 of the fifth embodiment in FIG.
It has a structure in which the electric plate 20 is replaced. The non-piezoelectric plate 20
The thickness h is 1.5 mm. Piezoelectric substrate 11 and non-piezoelectric plate 2
0 is a two-layer structure part B_TForming a piezoelectric substrate 12 and a non-piezoelectric plate
20 is a two-layer structure part B_RTo form The ultrasonic switch of the present embodiment
When using the switching element, the upper end surface of the non-piezoelectric plate 20
Alternatively, either of the lower end faces may be in contact with each other. Seventh embodiment
Ultrasonic switching element is also effective as a switch
Perform the function. FIG. 26 shows the two-layer structure part B of FIG._TSmell
Position of the piezoelectric substrate 11 under two different electrical boundary conditions.
K calculated from phase velocity difference^TwoShows the relationship between the value and the fd value
It is a characteristic diagram. However, in FIG. 26, the non-piezoelectric plate 20
The speed of the transverse wave of the elastic wave propagating through the piezoelectric plate 20 alone is 198.
A material whose longitudinal wave velocity is 3597 m / s at 8 m / s
A characteristic diagram for quality is shown. This transverse wave speed 198
The values 8 m / s and 3597 m / s longitudinal wave velocity are
Transverse wave velocity 2450 m / s in the case of the electric board 11 alone and
About 0.8 times each of the longitudinal wave velocities of 4390 m / s.
You. In FIG. 26, A₀Mode k^TwoOnly the value is always below 5%
ing. Therefore, A₀Mode except mode, that is, S₀
Mode and primary (A₁And S₁) Of higher modes
Efficient elastic wave in two-layer structure part B_TCan be excited by
Call FIG. 27 shows the two-layer structure part B of FIG._TPropagating elasticity
FIG. 4 is a characteristic diagram illustrating a velocity dispersion curve of a wave, with respect to an fd value.
It is a figure showing the phase velocity of each mode. However, in FIG.
Is a characteristic when the non-piezoelectric plate 20 is made of the same material as that of FIG.
A gender diagram is shown. The mark ● is added to the IDT 14
Electrical energy is most efficiently applied to the elastic waves in each mode.
The converted fd value (the value calculated from FIG. 26, k^TwoIs the best
Fd value indicating a large value). In FIG. 27, V_{fd = 0}The value is about 3
500 m / s. ● The phase velocity at the mark is almost V
_{fd = 0}It turns out that it is equal to a value. Thus, the two-layer structure
Structure B_TVelocity and V of elastic wave excited by_{fd = 0}Value
The fd value at the time of almost coincidence is k^TwoTo bring the maximum of
I understand. Ultrasonic switches of Figures 19, 22 and 25
In the switching element, the interdigital electrode 15 is connected to the interdigital electrode 16.
A replaceable structure is possible, as well as interdigital electrodes
14 and 15 replaced by interdigital electrodes 17 and 18
Unstructured structures are possible. Interdigital electrodes 16, 17 and
And 18 are interdigital electrodes 5, except for the value of the electrode period length.
6 and 7 have the same structure. IDT
The relative structure between poles 14 and 16 is shown in FIG.
The relative structure between the interdigital electrodes 3 and 5 is the same.
The relative structure between the interdigital electrodes 17 and 18 is shown in FIG.
As well as the relative structure between the interdigital electrodes 6 and 7 shown
It is. FIG. 28 shows a second embodiment of the ultrasonic switching element of the present invention.
It is sectional drawing which shows Example of FIG. In this embodiment, the input piezoelectric
Substrate 21, output piezoelectric substrate 22, non-piezoelectric plate 23, input
An IDT 24 includes an IDT 24 and an IDT 25 for output.
You. The interdigital electrodes 24 and 25 are connected to the piezoelectric substrate 21 and
22 are provided on the lower end surface. Piezoelectric substrate 21
And 22 are non-piezoelectric plates 23
Is fixed to the lower end surface of the cover. The piezoelectric substrates 21 and 22
The thickness d is 200 μm, and the direction of the polarization axis is
Placed in a direction parallel to the direction of the electrode finger of the pole 24
Have been. The non-piezoelectric plate 23 has a thickness h of 200 μm.
Interface between piezoelectric substrate 21 and non-piezoelectric plate 23 and piezoelectric substrate 2
The interface between 2 and the non-piezoelectric plate 23 is electrically open.
The piezoelectric substrate 21 and the non-piezoelectric plate 23 have a two-layer structure B_TForm
The piezoelectric substrate 22 and the non-piezoelectric plate 23 are_RThe shape
To achieve. Between the interdigital electrodes 24 and 25 in FIG.
Is the structure of the interdigital transducers 3 and 4 shown in FIG.
It is the same as the relative structure between them. Three pairs of interdigital electrodes 24
Electrode period length P is 290 μm,
The intersection width L is 15 mm. Ultrasonic switch of this embodiment
When using a non-piezoelectric element, the upper end surface of the non-piezoelectric plate 23 or
Either of the lower end surfaces may be in contact. Eighth Embodiment Supersonic
When driving the wave switching element, the circuit configuration of FIG.
Used. However, the IDTs 3 and 4 in FIG.
Replaced by drooping electrodes 24 and 25. Blinds
When an electric signal is input from the electrode 24, the two-layer structure B_TTo
An SH wave is excited. The SH wave propagates through the non-piezoelectric plate 23.
Transported, and the two-layer structure B_RTo the part R_1a
And R_1bThe electric signal E_1aAnd E_1bTo each
Is converted. The interdigital electrodes 24 and 25 are non-piezoelectric plates
In 23, the part R_1aAnd R_1bCorresponding to each
Ultrasonic wave propagation path Z_1aAnd Z_1bTo form Eighth embodiment
Ultrasonic switching element is also effective as a switch
Perform the function. FIG. 29 shows the two-layer structure part B of FIG._TSmell
Of the piezoelectric substrate 21 under two different electrical boundary conditions
K calculated from phase velocity difference^TwoValue, SH wave frequency f and pressure
Characteristics showing the relationship between the product (fd) and the thickness d of the circuit board 21
FIG. However, in FIG. 29, the non-piezoelectric plate 23
The speed of the transverse wave propagating to the plate 23 alone is 1988 m / s,
When the longitudinal wave speed is 3597m / s
Is shown. The shear wave speed of 1988 m / s and
The value of 3597 m / s and the longitudinal wave velocity are
Shear wave velocity 2450 m / s and longitudinal wave velocity 43 for body
It is approximately 0.8 times each of 90 m / s. Fig. 29
It can be seen that the SH waves in the higher order modes of the 0th order and the 1st or higher order are large.
k^TwoValues, but especially higher
Mode SH waves are easy to handle in device design
You can see that. In this way, for example,
The electrical energy applied to the pole 24 is the second mode S
The fd value of about 3.3 MHz is most easily converted to H wave.
Mm, then k^TwoThe value is about 2 of the maximum
Reaches 2.5%. FIG. 30 shows the two-layer structure part B of FIG._TTo
FIG. 4 is a characteristic diagram showing a velocity dispersion curve of a propagating SH wave, and f
It is a figure showing the phase velocity of each mode to d value. However
In FIG. 30, the non-piezoelectric plate 23 is made of the same material as in FIG.
A characteristic diagram is shown in the case of the following. ● The mark is IDT 2
The electric energy added to 4 is converted to SH wave of each mode
Fd value converted most efficiently (value calculated from FIG. 29)
And k^TwoIndicates the maximum value (fd value). From FIG.
● Each phase velocity in the mark propagates to the non-piezoelectric plate 23 alone
Of the shear wave velocity and the shear wave velocity propagating to the piezoelectric substrate 21 alone.
It can be seen that it is almost equal to the average value (2219 m / s).
Thus, the two-layer structure part B_TOf SH wave propagating through
Phase velocity, transverse wave velocity propagating to non-piezoelectric plate 23 alone and
The average value of the transverse wave velocity propagating to the piezoelectric substrate 21 alone is substantially
The fd value at the time of coincidence is k^TwoCan result in a maximum of
I understand. In the ultrasonic switching element shown in FIG.
A structure in which the interdigital electrode 25 is replaced with the interdigital electrode 26 is possible.
And the interdigital electrodes 24 and 25 are
A structure in which the electrodes 27 and 28 are replaced is possible.
You. The interdigital electrodes 26, 27 and 28 have an electrode period length
Except for the value of and the number of electrode fingers,
And 7 have the same structure. IDT 2
The relative structure between 4 and 26 is the blind shown in FIG.
Similar to the relative structure between the electrodes 3 and 5
The relative structure between the electrodes 27 and 28 is shown in FIG.
The relative structure between the interdigitated electrodes 6 and 7
You. FIG. 31 shows a ninth embodiment of the ultrasonic switching element of the present invention.
It is sectional drawing which shows an Example. In this embodiment, the piezoelectric substrate 21 and
And 22, non-piezoelectric plate 29, interdigital electrodes 24 and 25
Consists of The interdigital electrodes 24 and 25 are
And 22 are provided on the upper end surface. Piezoelectric base
The plates 21 and 22 are non-piezoelectric
It is fixed to the upper end surface of the plate 29. Non-piezoelectric plate 29 is thick
h is 400 μm. Polarization of piezoelectric substrates 21 and 22
The direction of the axis is parallel to the direction of the electrode fingers of the IDT 24.
It is arranged in such a direction. Piezoelectric substrate 21 and non-piezoelectric
Between the piezoelectric substrate 22 and the non-piezoelectric plate 29.
The interface is in an electrically shorted state. Piezoelectric substrate 21 and non-piezoelectric
The plate 29 has a two-layer structure B_TIs formed, and the piezoelectric substrate 22 and the non-pressure
The electric plate 29 has a two-layer structure B_RTo form Supersonic of this embodiment
When using a wave switching element, the non-piezoelectric plate 29
Touch the end face. Ultrasonic switching element of ninth embodiment
When driving the child, the circuit configuration of FIG. 4 is used. However
The interdigital electrodes 3 and 4 of FIG.
And 25. The electric current
When the air signal is input, the two-layer structure B_TSH wave is excited
It is. The SH wave propagates to the upper end surface of the non-piezoelectric plate 29,
Further, a two-layer structure B_RTo the part R_1aAnd R
_1bThe electric signal E_1aAnd E_1bAre converted to
You. The interdigital electrodes 24 and 25 are
And part R_1aAnd R_1bUltrasonic transmission corresponding to each
Carriage Z_1aAnd Z_1bTo form Ultrasound of ninth embodiment
Switching elements also perform an effective function as switches.
Add FIG. 32 shows the two-layer structure part B of FIG._TPiezoelectric base in
Phase velocity difference under two different electrical boundary conditions of plate 21
K calculated from^TwoValue, SH wave frequency f and piezoelectric substrate 2
FIG. 4 is a characteristic diagram showing a relationship between a product (fd) and a thickness d of No. 1;
You. However, in FIG. 32, the non-piezoelectric plate 29 is
The velocity of the shear wave propagating to a single body is 4203 m / s,
Specially made of a material whose speed is 7604 m / s
A gender diagram is shown. The shear wave speed of 4203 m / s and the vertical
The value of the wave velocity of 7604 m / s is the value of the piezoelectric substrate 21 alone.
Transverse wave velocity 2450 m / s and longitudinal wave velocity 4390
It is approximately 1.7 times each of m / s. From FIG. 31, 0
The SH waves of the higher order modes of the first and higher order are large k^Twovalue
It can be seen that For example, for the interdigital electrode 24
The applied electric energy is maximum in the 0th-order mode SH wave.
Is easily converted because the fd value is about 0.6 MHz
And then k^TwoThe value is about 33.8% of the maximum value
Reach. FIG. 33 shows a two-layer structure part B of FIG._TPropagate S
FIG. 4 is a characteristic diagram illustrating a velocity dispersion curve of an H wave, with respect to an fd value.
FIG. 4 is a diagram showing a phase velocity in each mode. However, in FIG.
Is a characteristic when the non-piezoelectric plate 29 is made of the same material as that of FIG.
A gender diagram is shown. The mark ● is added to the IDT 24
Electric energy is the most efficient for the SH wave of each mode
Fd value to be converted (value calculated from FIG. 32, k^TwoIs the best
Fd value indicating a large value). From FIG. 33,
The phase velocities are the transverse wave velocity propagating to the non-piezoelectric plate 29 alone and
And the average value of the transverse wave velocity propagating to the piezoelectric substrate 21 alone (33
27m / s). Like this
And the two-layer structure B_TThe phase velocity of the SH wave propagating through
Lateral wave velocity propagating to the piezoelectric plate 29 alone and the piezoelectric substrate 21
F near the average value of the velocity of the shear wave propagating to a single substance
d value is k^TwoIt can be seen that the maximum value of In FIG.
In an ultrasonic switching element, the interdigital electrodes 25
It is possible to have a structure in which
In addition, the interdigital electrodes 24 and 25 are
And 28 are possible.

According to the second structure of the interdigital transducer included in the ultrasonic switching element of the present invention, the intersecting area of the electrode fingers of the output interdigital transducer is one group R _i (i
= 1) or N groups R _i (i =
1, 2,..., N) and two groups R _i and R _{(i + 1)}
(N-1) parts Q _i ｛i = 1, 2,.
.., (N-1)}. The second structure of the interdigital transducer included in the ultrasonic switching element of the present invention is such that the intersecting region of the electrode fingers of the input interdigital transducer is N.
Parts A _i (i = 1, 2,..., N) and (N−1) parts B sandwiched between two parts A _i and A _{(i + 1)
i} {i = 1, 2,..., (N-1)},
The intersecting area of the electrode fingers of the output IDT is (N + 1)
Number of partial _{C i {i = 1,2, ......} , (N + 1)} and, 2
N parts D sandwiched between two parts C _i and C _{(i + 1)
i} (i = 1, 2,..., N). When the ultrasonic switching element of the present invention has the second structure of the interdigital electrode, the ultrasonic wave propagated to the non-piezoelectric plate has a portion R _ia
And R _ib , the electric signals E _ia and E _ib (i = 1,
2,..., N). The amplitude of the electric signal generated by combining the electric signals E _ia and E _ib becomes zero. The input and output interdigital electrodes form ultrasonic propagation paths Z _ia and Z _ib (i = 1, 2,..., N) corresponding to the portions R _ia and R _{ib on the} non-piezoelectric plate. If, when one Z _Xa of the 2N ultrasonic propagation path of non-piezoelectric plate in contact with a human finger or an object is cut off, the ultrasonic propagation path Z _Xb forming the ultrasonic wave propagation path Z _Xa paired electrical signals E _Xb corresponding to is output from the output interdigital transducer. Similarly, when the ultrasonic propagation path Z _Xb is blocked, the electric signal E _Xa corresponding to the ultrasonic propagation path Z _Xa is output from the output interdigital transducer. In this manner, the ultrasonic switching element of the present invention can generate an electric signal by contacting the non-piezoelectric plate, and can output an electric signal according to the contacted position. Therefore, it is possible to fulfill the function as a switch. When the ultrasonic switching element of the present invention has the second structure of the interdigital transducer, the ultrasonic wave propagated to the non-piezoelectric plate receives N electric signals E _ia (i =
1, 2,..., N) and N electric signals E _ib (i =
1, 2,..., N). The amplitude of the electric signal generated by combining the electric signals E _ia and E _ib becomes zero. The input and output IDTs are composed of N ultrasonic wave propagation paths Z _ia (i = 1, 2,...,
N) and N ultrasonic propagation paths Z _ib (i = 1, 2,...)
.., N) are formed. If a finger or an object comes into contact with the non-piezoelectric plate and one of these ultrasonic transmission paths Z _Xa is cut off, the ultrasonic transmission path Z _Xb that forms a pair with the ultrasonic transmission path Z _{Xa is} turned on. A corresponding electrical signal _EXb is output from the output IDT. Similarly, when the ultrasonic propagation path Z _Xb is blocked, the electric signal E _Xa corresponding to the ultrasonic propagation path Z _Xa is output from the output interdigital transducer. In this manner, the ultrasonic switching element of the present invention can generate an electric signal by contacting the non-piezoelectric plate, and can output an electric signal according to the contacted position. Therefore, it is possible to fulfill the function as a switch.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the ultrasonic switching element of the present invention.

FIG. 2 is a plan view of the ultrasonic switching element of FIG.

FIG. 3 is an enlarged plan view of a portion R _1m .

FIG. 4 is a circuit configuration diagram of the ultrasonic switching element of FIG. 1;

FIG. 5 is a characteristic diagram showing a relationship between a k ² value calculated from a phase velocity difference between two different electrical boundary conditions of the piezoelectric substrate 1 and a kh value.

FIG. 6 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating near the surface of the piezoelectric substrate 1.

FIG. 7 is a characteristic diagram showing a relationship between a k ² value calculated from a phase velocity difference between two different electric boundary conditions of the piezoelectric substrate 1 and a kh value.

FIG. 8 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating near the surface of the piezoelectric substrate 1.

FIG. 9 is a plan view showing a second embodiment of the ultrasonic switching element of the present invention.

FIG. 10 is an enlarged plan view of a portion Q _1.

FIG. 11 is a plan view showing a third embodiment of the ultrasonic switching element of the present invention.

Enlarged plan view of FIG. 12 parts B _1.

Figure 13 is an enlarged plan view of a portion D _1.

FIG. 14 is a sectional view showing a fourth embodiment of the ultrasonic switching element of the present invention.

FIG. 15 is a characteristic diagram showing a relationship between a k ² value calculated from a phase velocity difference between two piezoelectric substrates 8 and 9 under two different electrical boundary conditions, and an fd value.

FIG. 16 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating through the piezoelectric substrate 8 or 9;

FIG. 17 is a characteristic diagram showing a relationship between a k ² value calculated from a phase velocity difference between two piezoelectric substrates 8 and 9 under different electric boundary conditions, and an fd value.

FIG. 18 is a characteristic diagram showing a velocity dispersion curve of a surface acoustic wave propagating through the piezoelectric substrate 8 or 9.

FIG. 19 is a sectional view showing a fifth embodiment of the ultrasonic switching element of the present invention.

20 is a diagram showing a piezoelectric substrate 1 in the two-layer structure part _BT in FIG. 19;
And k ² values calculated from the phase velocity difference between the two electrical boundary conditions of different 1, characteristic diagram showing the relationship between the fd value.

[21] characteristic diagram showing the velocity dispersion curve of the acoustic wave propagating a two-layer structure B _T of Figure 19.

FIG. 22 is a sectional view showing a sixth embodiment of the ultrasonic switching element of the present invention.

FIG. 23 shows a piezoelectric substrate 1 in the two-layer structure part _BT in FIG.
And k ² values calculated from the phase velocity difference between the two electrical boundary conditions of different 1, characteristic diagram showing the relationship between the fd value.

[24] characteristic diagram showing the velocity dispersion curve of the acoustic wave propagating a two-layer structure B _T in FIG. 22.

FIG. 25 is a sectional view showing a seventh embodiment of the ultrasonic switching element of the present invention.

26 shows a piezoelectric substrate 1 in the two-layer structure part _BT in FIG.
And k ² values calculated from the phase velocity difference between the two electrical boundary conditions of different 1, characteristic diagram showing the relationship between the fd value.

[27] characteristic diagram showing the velocity dispersion curve of the acoustic wave propagating a two-layer structure B _T in FIG. 25.

FIG. 28 is a sectional view showing an eighth embodiment of the ultrasonic switching element of the present invention.

29 shows a piezoelectric substrate 2 in the two-layer structure part _BT in FIG. 28.
And k ² values calculated from the phase velocity difference between the two electrical boundary conditions of different 1, characteristic diagram showing the relationship between the fd value.

[Figure 30] characteristic diagram showing the velocity dispersion curve of the SH wave propagating a two-layer structure B _T in FIG. 28.

FIG. 31 is a sectional view showing a ninth embodiment of the ultrasonic switching element of the present invention.

FIG. 32 shows a piezoelectric substrate 2 in the two-layer structure part _BT in FIG.
And k ² values calculated from the phase velocity difference between the two electrical boundary conditions of different 1, characteristic diagram showing the relationship between the fd value.

[Figure 33] characteristic diagram showing the velocity dispersion curve of the SH wave propagating a two-layer structure B _T in FIG. 31.

[Explanation of symbols]

1 Piezoelectric substrate 2,10,13,19,20,23,29 Non-piezoelectric plate 3,6,14,17,24,27 IDT for input 4,5,7,15,16,18,25,26 , 28
Output IDT 8,11,21 Input piezoelectric substrate 9,12,22 Output piezoelectric substrate AMP amplifier

Claims (17)

[Claims] 1. An ultrasonic switching element comprising a piezoelectric substrate, a non-piezoelectric plate, input and output IDTs, wherein said input and output IDTs are provided on an upper end surface of said piezoelectric substrate, The lower end surface of the non-piezoelectric plate is fixed to the upper end surface of the piezoelectric substrate via the input and output IDTs, and the intersection area of the output IDTs is one group. R _i (i = 1) or sandwiched between N groups R _i (i = 1, 2,..., N) and the two groups R _i and R _{(i + 1)} -1) pieces Q _i
{I = 1,2, ......, ( N-1)} consists, each group R _i comprises two portions R _ia and R _ib, from a portion sandwiched by R _{i m} to, the moiety R The directions of the electrode fingers of _ia and R _ib are parallel to the directions of the electrode fingers of the input IDT, and the electrode cycle lengths of the portions R _ia and R _ib are the electrode _pitch P of the input IDT. equally, the moiety R electrode fingers of _im has an inclination of angle α with respect to the electrode fingers of said input interdigital transducer, said portion R periodicity P _RN electrode fingers in a direction perpendicular to the electrode fingers of the _im It is equal to the product of the electrode periodicity P and cos [alpha], wherein the electrode crossing width of the portion R _im, and overlap length L _RP in the direction of the electrode fingers of the part R _im, of the input interdigital transducer There are two types, an intersection width L _{RN in} a direction parallel to the electrode finger, and the intersection width L _RP is equal to the intersection width L _RN and secα. And the same as the product of half of the electrode period length P and cosec α, and the electrode finger of the portion Q _i has an inclination of ± β with respect to the electrode finger of the input IDT; periodicity P _QN of the electrode fingers in a direction perpendicular to the electrode fingers of the part Q _i is equal to the product of the electrode periodicity P and cos .beta, the electrode crossing width of the portion Q _i, the portion Q _i and overlap length L _QP in the direction of the electrode fingers, there are two types of cross width L _QN in the direction parallel to the electrode fingers of said input interdigital transducer, the overlap length L _QP is the overlap length L _QN The sum of the electrode cross widths of the portions R _ia and R _ib , the cross width L _RN, and the cross width L _QN is equal to the electrode cross width L of the input IDT. The input IDTs are almost equal to each other, and receive an electric signal having a frequency substantially corresponding to the electrode period length P. Accordingly, the excited surface acoustic wave having a wavelength approximately equal to the electrode periodicity P in the vicinity of the surface of the upper end surface of the piezoelectric substrate, to propagate the surface acoustic wave on the upper end surface of the non-piezoelectric plate, the moiety R _ia and R _ib convert the surface acoustic waves into electric signals E _ia and E _ib (i = 1, 2,..., N), respectively, and generate electric signals generated by combining the electric signals E _ia and E _ib. The amplitude of the signal is zero, and the input and output IDTs are provided on the upper end face of the non-piezoelectric plate at the ultrasonic propagation paths Z _ia and Z _ib corresponding to the portions R _ia and R _ib, respectively. i = 1
2,..., N), wherein the output IDT is one of the ultrasonic wave propagation paths _Zia and _{Zib when} a finger or an object contacts the upper end surface of the non-piezoelectric plate. one Z _Xa is only when it is cut off, the ultrasonic propagation path Z _Xa and whether to output the electric signal E _Xb corresponding to the ultrasonic propagation path Z _Xb paired, or the upper end surface of the non-piezoelectric plate An ultrasonic switching element that outputs an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa only when the ultrasonic wave propagation path Z _Xb is interrupted by contact. 2. An ultrasonic switching element comprising a piezoelectric substrate, a non-piezoelectric plate, input and output IDTs, wherein said input and output IDTs are provided on an upper end surface of said piezoelectric substrate, The lower end surface of the non-piezoelectric plate is fixed to the upper end surface of the piezoelectric substrate via the input and output IDTs, and the intersection region of the input IDTs has N portions. A _i (i = 1, 2,..., N) and (N−1) parts B sandwiched between the two parts A _i and A _{(i + 1)
i} {i = 1, 2,..., (N−1)}, and the intersection area of the electrode fingers of the output IDT is (N +
1) parts C _i {i = 1, 2,..., (N + 1)}
And N portions D _i (i = 1, 2,..., N) sandwiched between the two portions C _i and C _{(i + 1),} and the direction of the electrode finger of the portion A _i is In parallel with the direction of the electrode finger of the portion C _i, the electrode finger of the portion B _{i has} an angle − with respect to the electrode finger of the portion A _i.
has a slope of β, and the period length P _BN of the electrode finger in the direction orthogonal to the electrode finger of the portion B _i is equal to the product of the electrode period length P of the portions A _i and C _i and cos β; the electrode cross width of the portion B _i, the overlap length L _BP in the direction of the electrode fingers of the portion B _i, there are two types of cross width L _BN in a direction parallel to the electrode fingers of the part a _i , The intersection width L _BP
Equal to the product of the overlap length L _BN and secβ, the portion D _i is the electrode finger the part C corner to the electrode fingers of the _i alpha
Has a slope, periodicity P _DN of the electrode fingers in a direction perpendicular to the electrode fingers of the part D _i is equal to the product of the electrode periodicity P and cos [alpha], the electrode crossing width of the portion D _i , the portion D and the overlap length L _DP in the direction of the _i electrode fingers of, there are two types of cross width L _DN in a direction parallel to the electrode fingers of the portions C _i, the overlap length L _DP
Is equal to the product of the intersection width L _DN and secα,
It is equal to the product of half of the electrode cycle length P and cosec α, and the sum of the electrode finger intersection width and the intersection width L _BN of the portion A _{i is} the electrode finger intersection width and the intersection width L of the portion C _{i. The} input IDT is substantially equal to the sum of the _{DNs, and} the input IDT is supplied with an electric signal having a frequency substantially corresponding to the electrode cycle length P, so that the electrode cycle length near the surface of the upper end surface of the piezoelectric substrate. A surface acoustic wave having a wavelength substantially equal to P is excited, and the surface acoustic wave is propagated to the upper end surface of the non-piezoelectric plate. The output IDT converts the surface acoustic wave into N electric signals E _ia. (I = 1, 2,..., N) and N electric signals E _ib (i = 1, 2,..., N), and are generated by combining the electric signals E _ia and E _ib. The amplitude of the electrical signal is zero, and the input and output , In the upper end surface of the non-piezoelectric plate, N numbers of ultrasonic propagation path Z _ia (i =
1, 2,..., N) and N ultrasonic propagation paths Z _ib (i
= 1, 2,..., N), and the output interdigital transducer is configured to allow the upper end surface of the non-piezoelectric plate to come into contact with a human finger or an object so that the ultrasonic propagation paths _Zia and _Zib when one Z _Xa of out is interrupted only, the of the ultrasonic propagation path Z _Xa and whether to output the electric signal E _Xb corresponding to the ultrasonic propagation path Z _Xb paired, or the non-piezoelectric plate An ultrasonic switching element that outputs an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa only when the ultrasonic wave propagation path Z _Xb is cut off by contacting the upper end surface. 3. An ultrasonic switching device comprising an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs, wherein said input and output IDTs are said input and output IDTs. The input and output piezoelectric substrates are provided on one plate surface of the respective piezoelectric substrates, and the non-piezoelectric substrate is provided through the one plate surface or the other plate surface of the input and output piezoelectric substrates, respectively. The intersecting region of the electrode fingers of the output IDT, which is fixed to the upper end surface of the plate, consists of one group R _i (i = 1) or N groups R _i (i = 1,2). ,..., N) and (N−1) parts Q _i sandwiched between the two groups R _i and R _{(i + 1)}
{I = 1,2, ......, ( N-1)} consists, each group R _i comprises two portions R _ia and R _ib, from a portion sandwiched by R _{i m} to, the moiety R The directions of the electrode fingers of _ia and R _ib are parallel to the directions of the electrode fingers of the input IDT, and the electrode cycle lengths of the portions R _ia and R _ib are the electrode _pitch P of the input IDT. equally, the moiety R electrode fingers of _im has an inclination of angle α with respect to the electrode fingers of said input interdigital transducer, said portion R periodicity P _RN electrode fingers in a direction perpendicular to the electrode fingers of the _im It is equal to the product of the electrode periodicity P and cos [alpha], wherein the electrode crossing width of the portion R _im, and overlap length L _RP in the direction of the electrode fingers of the part R _im, of the input interdigital transducer There are two types, an intersection width L _{RN in} a direction parallel to the electrode finger, and the intersection width L _RP is equal to the intersection width L _RN and secα. And the same as the product of half of the electrode period length P and cosec α, and the electrode finger of the portion Q _i has an inclination of ± β with respect to the electrode finger of the input IDT; periodicity P _QN of the electrode fingers in a direction perpendicular to the electrode fingers of the part Q _i is equal to the product of the electrode periodicity P and cos .beta, the electrode crossing width of the portion Q _i, the portion Q _i and overlap length L _QP in the direction of the electrode fingers, there are two types of cross width L _QN in the direction parallel to the electrode fingers of said input interdigital transducer, the overlap length L _QP is the overlap length L _QN The sum of the electrode cross widths of the portions R _ia and R _ib , the cross width L _RN, and the cross width L _QN is equal to the electrode cross width L of the input IDT. The input IDTs are almost equal to each other, and receive an electric signal having a frequency substantially corresponding to the electrode period length P. Then, a surface acoustic wave having a wavelength substantially equal to the electrode period length P is excited on the input piezoelectric substrate, and the surface acoustic wave is propagated to the upper end surface of the non-piezoelectric plate. The parts R _ia and R _ib convert the surface acoustic waves into electric signals E _ia and E _ib (i = 1, 2,..., N), respectively, and the electric signals E _ia and E _ib The amplitude of the electric signal generated by combining the above-mentioned components is zero, and the input and output interdigital transducers are provided on the upper end face of the non-piezoelectric plate at the ultrasonic propagation corresponding to the portions R _ia and R _ib, respectively. The paths Z _ia and Z _ib (i = 1,
2,..., N), wherein the output IDT is one of the ultrasonic wave propagation paths _Zia and _{Zib when} a finger or an object contacts the upper end surface of the non-piezoelectric plate. one Z _Xa is only when it is cut off, the ultrasonic propagation path Z _Xa and whether to output the electric signal E _Xb corresponding to the ultrasonic propagation path Z _Xb paired, or the upper end surface of the non-piezoelectric plate An ultrasonic switching element that outputs an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa only when the ultrasonic wave propagation path Z _Xb is interrupted by contact. 4. An ultrasonic switching element comprising an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs, wherein said input and output IDTs are said input and output IDTs. The input and output piezoelectric substrates are provided on one plate surface of the respective piezoelectric substrates, and the non-piezoelectric substrate is provided through the one plate surface or the other plate surface of the input and output piezoelectric substrates, respectively. The intersecting region of the input finger of the input IDT is fixed to the upper end surface of the plate, and includes N portions A _i (i = 1, 2,..., N) and two of the portions A _i and A ₍ N-1) parts B sandwiched between _{(i + 1)
i} {i = 1, 2,..., (N−1)}, and the intersection area of the electrode fingers of the output IDT is (N +
1) parts C _i {i = 1, 2,..., (N + 1)}
And N portions D _i (i = 1, 2,..., N) sandwiched between the two portions C _i and C _{(i + 1),} and the direction of the electrode finger of the portion A _i is In parallel with the direction of the electrode finger of the portion C _i, the electrode finger of the portion B _{i has} an angle − with respect to the electrode finger of the portion A _i.
has a slope of β, and the period length P _BN of the electrode finger in the direction orthogonal to the electrode finger of the portion B _i is equal to the product of the electrode period length P of the portions A _i and C _i and cos β; the electrode cross width of the portion B _i, the overlap length L _BP in the direction of the electrode fingers of the portion B _i, there are two types of cross width L _BN in a direction parallel to the electrode fingers of the part a _i , The intersection width L _BP
Equal to the product of the overlap length L _BN and secβ, the portion D _i is the electrode finger the part C corner to the electrode fingers of the _i alpha
Has a slope, periodicity P _DN of the electrode fingers in a direction perpendicular to the electrode fingers of the part D _i is equal to the product of the electrode periodicity P and cos [alpha], the electrode crossing width of the portion D _i , the portion D and the overlap length L _DP in the direction of the _i electrode fingers of, there are two types of cross width L _DN in a direction parallel to the electrode fingers of the portions C _i, the overlap length L _DP
Is equal to the product of the intersection width L _DN and secα,
Equal to the product of half of the electrode period length P and cosecα, the sum of the intersection width of the electrode fingers of the portion A _i and the intersection width L _BN is the intersection width of the electrode fingers of the portion C _i and the intersection width L _The input IDT has a wavelength substantially equal to the electrode cycle length P when the input IDT is supplied with an electric signal having a frequency substantially corresponding to the electrode cycle length P. Is excited, and after the surface acoustic wave propagates to the upper end surface of the non-piezoelectric plate, the surface acoustic wave propagates to the output piezoelectric substrate. _Are converted into N electric signals E _ia (i = 1, 2,..., N) and N electric signals E _ib (i = 1, 2,..., N), and the electric signals E _ia and E amplitude of the electrical signal produced by synthesizing the _ib is zero, for the input Auxiliary output interdigital transducer, in the upper end surface of the non-piezoelectric plate, N numbers of ultrasonic propagation path Z _ia (i =
1, 2,..., N) and N ultrasonic propagation paths Z _ib (i
= 1, 2,..., N), and the output interdigital transducer is configured to allow the upper end surface of the non-piezoelectric plate to come into contact with a human finger or an object so that the ultrasonic propagation paths _Zia and _Zib when one Z _Xa of out is interrupted only, the of the ultrasonic propagation path Z _Xa and whether to output the electric signal E _Xb corresponding to the ultrasonic propagation path Z _Xb paired, or the non-piezoelectric plate An ultrasonic switching element that outputs an electric signal _EXa corresponding to the ultrasonic wave propagation path Z _Xa only when the ultrasonic wave propagation path Z _Xb is cut off by contacting the upper end surface. 5. The thickness d of the piezoelectric substrate is about three times or more the electrode period length P, the thickness h of the non-piezoelectric plate is smaller than the electrode period length P, The phase velocity of a propagating surface acoustic wave is
The direction of the polarization axis of the piezoelectric substrate is parallel to the direction of its thickness d, and the surface acoustic wave has a zero-order mode and a primary or higher order. In the higher-order mode wave, the phase velocity of the zero-order mode surface acoustic wave is
The phase velocity of the surface acoustic wave in the first or higher order mode is substantially equal to the velocity of the Rayleigh wave propagating to the piezoelectric substrate alone in an electrically shorted state, and the phase velocity of the piezoelectric substrate alone in the electrically open state 3. The ultrasonic switching element according to claim 1, wherein the velocity of the Rayleigh wave propagating through the ultrasonic switching element is substantially equal to the velocity. 6. The thickness d of each of the piezoelectric substrates is smaller than the electrode period length P, the thickness h of the non-piezoelectric plate is approximately three times or more the electrode period length P, and the non-piezoelectric plate alone The phase velocity of the surface acoustic wave propagating in
The direction of the polarization axis of each piezoelectric substrate is parallel to the direction of its thickness d, which is greater than the phase velocity of the surface acoustic wave propagating to each piezoelectric substrate alone, and the surface acoustic wave has a first-order or higher height. In the next mode wave,
The ultrasonic switching element according to claim 3, wherein a phase velocity of the surface acoustic wave of a higher order mode or higher is approximately equal to a velocity of a Rayleigh wave propagating to the non-piezoelectric plate alone. 7. An ultrasonic switching element comprising an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs, wherein said input and output IDTs are said input and output IDTs. The input and output piezoelectric substrates are provided on one plate surface of each of the piezoelectric substrates, and the non-piezoelectric substrate is provided through the one plate surface or the other plate surface of each of the input and output piezoelectric substrates. The intersecting region of the electrode fingers of the output IDT, which is fixed to one plate surface of the plate, consists of one group R _i (i = 1) or N groups R _i (i = 1) , 2,..., N) and (N−1) parts Q _i sandwiched between the two groups R _i and R _{(i + 1)}
{I = 1,2, ......, ( N-1)} consists, each group R _i comprises two portions R _ia and R _ib, from a portion sandwiched by R _{i m} to, the moiety R The directions of the electrode fingers of _ia and R _ib are parallel to the directions of the electrode fingers of the input IDT, and the electrode cycle lengths of the portions R _ia and R _ib are the electrode _pitch P of the input IDT. equally, the moiety R electrode fingers of _im has an inclination of angle α with respect to the electrode fingers of said input interdigital transducer, said portion R periodicity P _RN electrode fingers in a direction perpendicular to the electrode fingers of the _im It is equal to the product of the electrode periodicity P and cos [alpha], wherein the electrode crossing width of the portion R _im, and overlap length L _RP in the direction of the electrode fingers of the part R _im, of the input interdigital transducer There are two types, an intersection width L _{RN in} a direction parallel to the electrode finger, and the intersection width L _RP is equal to the intersection width L _RN and secα. And the same as the product of half of the electrode period length P and cosec α, and the electrode finger of the portion Q _i has an inclination of ± β with respect to the electrode finger of the input IDT; periodicity P _QN of the electrode fingers in a direction perpendicular to the electrode fingers of the part Q _i is equal to the product of the electrode periodicity P and cos .beta, the electrode crossing width of the portion Q _i, the portion Q _i and overlap length L _QP in the direction of the electrode fingers, there are two types of cross width L _QN in the direction parallel to the electrode fingers of said input interdigital transducer, the overlap length L _QP is the overlap length L _QN The sum of the electrode cross widths of the portions R _ia and R _ib , the cross width L _RN, and the cross width L _QN is equal to the electrode cross width L of the input IDT. The thickness d of each piezoelectric substrate is smaller than the electrode period length P, and the input IDT is After said an input piezoelectric substrate in a two-layer structure B _T made of a non-piezoelectric plate to excite the ultrasound was transmitted to the ultrasonic waves to the non-piezoelectric plate by inputting the item, piezoelectric for the output substrate and the propagate a two-layer structure B _R consisting of non-piezoelectric plate, the portion R _ia and R _ib, the ultrasonic electrical signals E _ia
, And E _ib (i = 1, 2,..., N), respectively, and the amplitude of the electric signal generated by combining the electric signals E _ia and E _ib is zero. In the non-piezoelectric plate, the ultrasonic electrodes Z _ia and Z _ib (i = 1, 2,..., N) corresponding to the portions R _ia and R _ib, respectively.
Forming a said output interdigital transducer, said single Z _Xa of the throat force one plate surface of the non-piezoelectric plate in contact with a human finger or an object the ultrasonic propagation path Z _ia and Z _ib is interrupted only when it is, the ultrasonic propagation path Z _Xb forming the ultrasonic propagation path Z _Xa paired
And outputs an electric signal E _Xb corresponding to or wherein when a non-piezoelectric plate of the contacts the throat force one plate surface ultrasonic propagation path Z _Xb is interrupted only, the ultrasonic propagation path Z _Xa An ultrasonic switching element that outputs a corresponding electric signal _EXa . 8. An ultrasonic switching device comprising an input and output piezoelectric substrate, a non-piezoelectric plate, and input and output IDTs, wherein said input and output IDTs are said input and output IDTs. The input and output piezoelectric substrates are provided on one plate surface of each of the piezoelectric substrates, and the non-piezoelectric substrate is provided through the one plate surface or the other plate surface of each of the input and output piezoelectric substrates. The intersecting areas of the electrode fingers of the input IDT are fixed to one plate surface of the plate, and include N portions A _i (i = 1, 2,..., N) and two of the portions A _i And (N-1) parts B sandwiched between A and _{(i + 1)
i} {i = 1, 2,..., (N−1)}, and the intersection area of the electrode fingers of the output IDT is (N +
1) parts C _i {i = 1, 2,..., (N + 1)}
And N portions D _i (i = 1, 2,..., N) sandwiched between the two portions C _i and C _{(i + 1),} and the direction of the electrode finger of the portion A _i is In parallel with the direction of the electrode finger of the portion C _i, the electrode finger of the portion B _{i has} an angle − with respect to the electrode finger of the portion A _i.
has a slope of β, and the period length P _BN of the electrode finger in the direction orthogonal to the electrode finger of the portion B _i is equal to the product of the electrode period length P of the portions A _i and C _i and cos β; the electrode cross width of the portion B _i, the overlap length L _BP in the direction of the electrode fingers of the portion B _i, there are two types of cross width L _BN in a direction parallel to the electrode fingers of the part a _i , The intersection width L _BP
Equal to the product of the overlap length L _BN and secβ, the portion D _i is the electrode finger the part C corner to the electrode fingers of the _i alpha
Has a slope, periodicity P _DN of the electrode fingers in a direction perpendicular to the electrode fingers of the part D _i is equal to the product of the electrode periodicity P and cos [alpha], the electrode crossing width of the portion D _i , the portion D and the overlap length L _DP in the direction of the _i electrode fingers of, there are two types of cross width L _DN in a direction parallel to the electrode fingers of the portions C _i, the overlap length L _DP
Is equal to the product of the intersection width L _DN and secα,
It is equal to the product of half of the electrode cycle length P and cosec α, and the sum of the electrode finger intersection width and the intersection width L _BN of the portion A _{i is} the electrode finger intersection width and the intersection width L of the portion C _i. approximately equal to the sum of _DN, the thickness d of the piezoelectric substrate is smaller than the electrode periodicity P, said input interdigital transducer, said piezoelectric substrate said input by inputting the electrical signal nonpiezoelectric exciting the ultrasonic two-layer structure section B _T consisting of a plate, the after ultrasound is propagated to the non-piezoelectric plate, propagation to a two-layer structure B _R consisting of the non-piezoelectric plate and the piezoelectric substrate wherein the output The output IDT converts the ultrasonic wave into N electric signals E _ia (i = 1, 2,..., N) and N electric signals E _ib (i = 1, 2,...). was converted to N), the amplitude of the electrical signal produced by synthesizing the electric signals E _ia and E _ib is , And the said input and output interdigital electrodes, in the non-piezoelectric plate, N numbers of ultrasonic propagation path Z
_ia (i = 1, 2,..., N) and N ultrasonic wave propagation paths Z _ib (i = 1, 2,..., N); only when one Z _Xa of said throat force one plate surface of the plate in contact with a human finger or an object ultrasonic propagation path Z _ia and Z _ib is interrupted, the ultrasonic propagation path Z _Xa paired Ultrasonic propagation path Z _Xb
And outputs an electric signal E _Xb corresponding to or wherein when a non-piezoelectric plate of the contacts the throat force one plate surface ultrasonic propagation path Z _Xb is interrupted only, the ultrasonic propagation path Z _Xa An ultrasonic switching element that outputs a corresponding electric signal _EXa . 9. The direction of the polarization axis of each of the piezoelectric substrates is parallel to the direction of its thickness d, and the thickness h of the non-piezoelectric plate is smaller than the thickness d of each of the piezoelectric substrates. The phase velocity of the elastic wave propagating to the piezoelectric plate alone is greater than the phase velocity of the elastic wave propagating to each piezoelectric substrate alone, and the input interdigital transducer has an electric frequency of a frequency substantially corresponding to the electrode cycle length P. by inputting a signal, after the elastic wave excited that have a wavelength substantially equal to the said electrode periodicity P in the two-layer structure section B _T, and by propagating the acoustic waves in the non-piezoelectric plate, the 2 is propagated in the layer structure B _R, the elastic wave is a wave of S ₀ mode and first-order or higher-order mode, the phase velocity of the acoustic wave excited in the two-layer structure B _T, the acoustic wave When the product fd of the frequency f and the thickness d of each piezoelectric substrate is near zero. Ultrasonic switching element approximately equal claim 7 or 8, wherein the phase velocity V _{fd = 0} of the acoustic wave in the S ₀ mode. 10. The direction of the polarization axis of each of the piezoelectric substrates is parallel to the direction of its thickness d. The thickness h of the non-piezoelectric plate is substantially equal to the thickness d of each of the piezoelectric substrates. The phase velocity of the elastic wave propagating through the piezoelectric plate alone is substantially equal to the phase velocity of the elastic wave propagating through each of the piezoelectric substrates alone, and the input IDT has an electric frequency having a frequency substantially corresponding to the electrode cycle length P. by inputting a signal, after the elastic wave excited that have a wavelength substantially equal to the said electrode periodicity P in the two-layer structure section B _T, and by propagating the acoustic waves in the non-piezoelectric plate, the 2 is propagated in the layer structure B _R, the elastic wave is a wave of S ₀ mode and first-order or higher-order mode, the phase velocity of the acoustic wave excited in the two-layer structure B _T, the acoustic wave The product fd of the frequency f and the thickness d of each piezoelectric substrate is near zero Ultrasonic switching element according to approximately equal claim 7 or 8 with a phase velocity V _{fd = 0} of the acoustic wave in the S ₀ mode. 11. The direction of the polarization axis of each piezoelectric substrate is parallel to the direction of its thickness d. The thickness h of the non-piezoelectric plate is greater than the thickness d of each piezoelectric substrate and The phase velocity of the elastic wave propagating through the non-piezoelectric plate alone is smaller than twice the thickness d of the piezoelectric substrate, and the phase velocity of the elastic wave propagating through each of the piezoelectric substrates alone is smaller than the input IDT. electrode, said by inputting a substantially electrical signal of a frequency corresponding to the electrode periodicity P, exciting the acoustic wave having a wavelength approximately equal to the electrode periodicity P in the two-layer structure B _T, the elastic After the wave is propagated through the non-piezoelectric plate, the wave is propagated to the two-layer structure part B _R , and the elastic wave is a wave of S ₀ mode and a first-order or higher order mode, and the two-layer structure part B _T The phase velocity of the elastic wave excited in the Ultrasonic switching element according to approximately equal claim 7 or 8 with a phase velocity V _{fd = 0} of the acoustic wave in the S ₀ mode when the product fd is in the vicinity of zero of the thickness d of the piezoelectric substrate. 12. The input and output piezoelectric substrates,
The input and output piezoelectric substrates are fixed to one plate surface of the non-piezoelectric plate via the other plate surfaces, respectively, and the interface of each piezoelectric substrate with the non-piezoelectric plate is electrically open. Wherein the direction of the polarization axis of each piezoelectric substrate is parallel to the direction of the electrode fingers of the input IDT, and the thickness h of the non-piezoelectric plate is substantially equal to the thickness d of each piezoelectric substrate. The non-piezoelectric plate is made of a material having a phase velocity of a transverse wave propagating to the non-piezoelectric plate alone that is substantially equal to or less than a phase speed of a transverse wave propagating to each of the piezoelectric substrates alone. the input interdigital transducer is by inputting an electric signal having a frequency substantially corresponding to the electrode periodicity P, SH wave having a wavelength approximately equal to the electrode periodicity P in the two-layer structure B _T To excite the SH wave After propagating in the electrodeposition plates, is propagated in the two-layer structure B _R, a wave of the SH wave is 0 order mode and first-order or higher-order mode, the phase velocity of the SH wave, the non-piezoelectric 9. The ultrasonic switching device according to claim 7, wherein an average value of the shear wave speed propagating in the single plate and an average value of the shear wave speed propagating in each of the piezoelectric substrates alone. 13. The input and output piezoelectric substrates,
The input and output piezoelectric substrates are fixed to one plate surface of the non-piezoelectric plate via the other plate surfaces, respectively, and the interface of each of the piezoelectric substrates with the non-piezoelectric plate is electrically short-circuited. Wherein the direction of the polarization axis of each piezoelectric substrate is parallel to the direction of the electrode fingers of the input IDT, and the thickness h of the non-piezoelectric plate is greater than the thickness d of each piezoelectric substrate. In addition, the non-piezoelectric plate has a phase velocity of a transverse wave propagating to the single non-piezoelectric plate larger than a phase velocity of a transverse wave propagating to the single piezoelectric substrate alone. made of a material, the input interdigital transducer, by inputting an electrical signal having a frequency substantially corresponding to the electrode period length P, the wavelength approximately equal to the electrode periodicity P in the two-layer structure B _T To excite the SH wave having After propagated to the one plate surface of the non-piezoelectric plate, the propagate a two-layer structure B _R, a wave of the SH wave is 0 order mode and first-order or higher-order mode, the SH wave phase The velocity is near the average value of the shear wave velocity propagating to the non-piezoelectric plate alone and the shear wave velocity propagating to each of the piezoelectric substrates alone, and the input and output interdigital transducers are the one of the non-piezoelectric plates. in the plate surface, the portion R _ia and ultrasonic wave propagation path R _ib corresponding to Z _ia and Z _ib (i =
1, 2,..., N), and the output interdigital transducer is configured such that a human finger or an object comes into contact with the one plate surface of the non-piezoelectric plate and the ultrasonic wave propagation path Z _ia.
And only when one of Z _ib Z _Xa is blocked,
An electric signal _EXb corresponding to the ultrasonic wave propagation path Z _Xb paired with the ultrasonic wave propagation path Z _Xa is output, or the one of the non-piezoelectric plates is brought into contact with the ultrasonic wave propagation path Z _Xa . only _{when Xb} is interrupted, ultrasonic switching element according to claim 7 or 8 outputs an electric signal E _Xa corresponding to the ultrasonic propagation path Z _Xa. 14. The cross width L _QP is equal to the electrode cycle length P.
Is divided by twice the number N of the groups R _i , and cosec β
The ultrasonic switching element according to claim 1, 3 or 7, which is equal to the product of: 15. The cross width L _BP is equal to the electrode cycle length P.
And a value obtained by dividing twice the number N of the partial A _i, ultrasonic switching element according to claim 2, 4 or 8 equal to the product of the Cosecbeta. 16. The piezoelectric substrate according to claim 1, wherein each of the piezoelectric substrates is made of a piezoelectric ceramic.
The ultrasonic switching element according to 11, 12, 13, 14, or 15. 17. The electric signal E _i-1 and E _i-2 each having a radio frequency.
5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
17. The ultrasonic switching element according to 15 or 16.