JPH1022543A - Piezoelectric transformer and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric transformer having prim. areas. The adjacent prim. areas are polarized reversely to each other. The transformer is fabricated, without causing electric discharge between adjacent prim. electrodes and polarized enough to well drive the piezoelectric oscillation. SOLUTION: The lengths g of the gap 251 between prim. electrodes 222, 226 and gap 252 between prim. electrodes 224, 228 are at least 20% the thickness t of a piezoelectric ceramic board 210 and set to G/(2k) or less; G is length of a piezoelectric transformer 10 in its length direction L and k is driving resonance wavelength in the direction L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a piezoelectric transformer and a method for manufacturing the same.

[0002]

2. Description of the Related Art The present inventors have divided a primary side into a plurality of primary side regions as shown in FIGS. 1 and 2, for example.
A piezoelectric transformer has been devised in which adjacent primary sides are polarized in directions opposite to each other in the thickness direction of the piezoelectric ceramic substrate.

In such a piezoelectric transformer, a predetermined gap is provided between the adjacent primary electrodes provided on the upper surface and the lower surface of the adjacent primary region, respectively.
A plurality of primary regions are sequentially polarized in the thickness direction.

[0004]

However, when a method of sequentially polarizing a plurality of primary regions is adopted as described above,
There is a problem that the polarization time becomes longer in proportion to the number of the primary regions and the working efficiency is poor.

Thus, the present inventors have considered a method of simultaneously polarizing a plurality of primary regions.
There is a problem that an electric field is also generated between the adjacent primary electrodes, and a discharge may occur between the adjacent primary electrodes. On the other hand, in order to prevent this discharge, a voltage between the adjacent primary electrodes is reduced. It has been found that, if the interval of is increased, the piezoelectric vibration may not be sufficiently excited.

Accordingly, an object of the present invention is to provide a piezoelectric transformer having a structure in which a plurality of primary regions are arranged and adjacent primary regions are polarized in directions opposite to each other. Another object of the present invention is to provide a piezoelectric transformer having a sufficient polarization and a sufficient excitation of piezoelectric vibration in a manufactured piezoelectric transformer, and a method of manufacturing the same.

[0007]

Means for Solving the Problems The inventors of the present invention have proposed a method for connecting adjacent ones.
When a plurality of electrodes in the secondary region are simultaneously polarized in the opposite direction, conditions for causing polarization without causing discharge during the polarization process were determined.The lower limit of the interval between the primary electrodes was a piezoelectric substrate. Found that it depends on the thickness. Further, as an upper limit value, it is assumed that excitation can be performed if the distance between adjacent primary electrodes is set to within 以内 of the exciting wavelength and the adjacent primary regions are polarized and an electric field is applied. The present invention has been found.

Therefore, according to the present invention, the first and second main surfaces opposing each other and the first and second end surfaces opposing each other, the first main surface and the second main surface. A substantially rectangular parallelepiped piezoelectric substrate having first and second end faces perpendicular to the first end face and the first end face side in a first direction substantially perpendicular to the first and second end faces. A piezoelectric substrate having a plurality of primary regions and a plurality of secondary regions in this order toward the second end surface; and a plurality of first substrates provided on the first main surface of the plurality of primary regions, respectively. A primary electrode, and a plurality of second primary electrodes respectively provided on the second main surface of the plurality of primary regions in opposition to the first primary electrode; At least one pair of the adjacent primary regions among the primary regions Are polarized in opposite directions in the first main surface and the thickness direction of the piezoelectric substrate between said second main surface, n between the first end surface and the second end face
(N is 1 or more and an integral multiple of 1/2) In a piezoelectric transformer drivable so that a resonance mode of a wavelength is established, the piezoelectric transformers are provided on the first main surfaces of the at least one pair of adjacent primary regions. The distance g in the first direction between the first primary electrodes adjacent to each other and the second second electrodes provided on the second main surfaces of the at least one pair of adjacent primary regions are adjacent to each other. The distance g between the primary electrodes in the first direction is not less than 20% of the thickness of the piezoelectric substrate between the first main surface and the second main surface, and the first end surface and the second end surface have the same thickness. Assuming that the distance between the end surfaces of G and G is G, G / (2 ·
n) A first piezoelectric transformer characterized by the following is provided.

As described above, the gap g in the first direction between the first primary electrodes adjacent to each other and provided on the first main surfaces of the primary regions adjacent to each other, and the distance g between the first primary regions adjacent to each other. The distance g in the first direction between the second primary electrodes provided on the second main surface and adjacent to each other is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. By doing so, even if the primary regions adjacent to each other are simultaneously polarized in the opposite directions, even if the primary regions adjacent to each other are provided on the first main surface and the primary regions adjacent to each other are provided on the second main surface, No discharge occurs between adjacent second primary electrodes.

[0010] Further, the distance between the first end face and the second end face is n.
(N is 1 or more and an integral multiple of 1/2) When driving can be performed so that a resonance mode of a wavelength is established, first primary surfaces provided on the first main surfaces of the primary regions adjacent to each other are respectively provided. The distance g in the first direction between the side electrodes and the distance g in the first direction between the mutually adjacent second primary electrodes provided on the second main surfaces of the mutually adjacent primary regions, respectively, The distance between the first end face and the second end face is G
In this case, by setting G and (2 · n) or less with respect to n and G, polarization is sufficiently performed even in the boundary region between the primary regions adjacent to each other, and as a result, piezoelectric vibration is sufficiently excited. Is done.

Note that the first piezoelectric transformer has a plurality of primary regions in a first direction substantially perpendicular to the first and second end faces, and the first piezoelectric transformer has a plurality of primary regions in the first direction. Since the piezoelectric transformer is drivable so that a resonance mode of n (n is 1 or more and an integral multiple of 波長) wavelength is established therebetween, each of the plurality of primary regions is either positive or negative at resonance. The primary regions adjacent to each other are polarized in opposite directions in the thickness direction of the piezoelectric substrate between the first main surface and the second main surface. To connect the first primary electrodes on the first main surfaces of the primary regions adjacent to each other in common, and share the second primary electrodes on the second main surfaces of the primary regions adjacent to each other in common. To the primary areas adjacent to each other. Also one of Les oscillates so as to increase the resonance of the piezoelectric substrate is excited by the other primary side regions adjacent to each other. As a result, on the primary side, the input electric energy can be more efficiently converted into mechanical elastic energy.

According to the present invention, the first main surface and the second main surface facing each other and the first and second end surfaces facing each other, wherein the first main surface and the second main surface are opposite to each other. A substantially rectangular parallelepiped piezoelectric substrate having first and second end faces perpendicular to the main surface of the first end face and the second end face.
A piezoelectric transformer drivable so that a resonance mode of n (n is 1 or more and an integral multiple of）) wavelength stands between the first and second end faces. At least a first primary region, a second primary region, and a secondary region separated from each other in one direction, wherein the first primary region and the second primary region are adjacent to each other; Wherein the first primary side region has a length of approximately half a wavelength of the stress distribution at the time of the resonance in the first direction, and either one of positive and negative in the first direction at the time of the resonance And a first primary side electrode and a second primary side electrode are provided on the first main surface and the second main surface of the first primary side region, respectively. The first primary side electrode and the second primary side of the first primary side region Said machining gap and said first major surface a second
Are polarized in a first predetermined direction in a second direction between the main surfaces of the first and second surfaces, and the second primary region has a length in the first direction that is equal to or less than a half wavelength of the stress distribution at the time of the resonance. And at the time of the resonance, an area in which the other of the positive and negative stresses in the first direction is opposite to the one of the stresses. A third primary side electrode and a fourth primary side electrode are respectively provided on the main surface of the second primary side so as to face each other, and a third primary side electrode and a fourth primary side electrode in the second primary side region are provided between the third primary side electrode and the fourth primary side electrode. Are polarized in the second direction in a second predetermined direction opposite to the first predetermined direction, and the first primary electrode and the third primary electrode can be electrically connected. Or is electrically connected to said second primary electrode and said fourth primary electrode. In a piezoelectric transformer in which electrodes are electrically connectable or electrically connected, a distance g in the first direction between the first primary electrode and the third primary electrode and The distance g between the second primary electrode and the fourth primary electrode in the first direction is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. Wherein G is the distance between the first end face and the second end face, and G / (2 · n) or less with respect to n and G.
Is provided.

Thus, the distance g in the first direction between the first primary electrode and the third primary electrode and the second
The distance g in the first direction between the primary electrode and the fourth primary electrode in the first direction is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. Even if the first primary region and the second primary region that are adjacent to each other are simultaneously polarized in opposite directions, the first primary electrode and the third primary electrode that are adjacent to each other and that are provided on the first main surface. Discharge does not occur between the electrodes and between the second primary electrode and the fourth primary electrode adjacent to each other provided on the second main surface.

Further, n is provided between the first end face and the second end face.
(N is 1 or more and an integral multiple of １ ／) When driving can be performed so that a resonance mode of a wavelength is established, the distance g in the first direction between the first primary electrode and the third primary electrode and The distance g between the second primary electrode and the fourth primary electrode in the first direction is G, and the distance between the first end face and the second end face is G.
When n and G are not more than G / (2 · n), the first primary region adjacent to the first region and the second region
Is sufficiently polarized also in the boundary region with the primary side region, and as a result, the piezoelectric vibration is sufficiently excited.

In the second piezoelectric transformer, a third primary electrode and a fourth primary electrode are provided in addition to the first primary electrode and the second primary electrode. The primary-side electrode area becomes larger, and the input impedance of the piezoelectric transformer decreases. As a result, electric energy is easily supplied from the power supply to the piezoelectric transformer.

The stresses generated in the first primary region and the second primary region at the time of resonance are opposite to each other, and the stress between the first primary electrode and the second primary electrode in the first primary region is reduced. Is opposite to the polarization direction between the third primary electrode and the fourth primary electrode in the second primary region, and the first primary electrode and the third primary electrode are electrically connected. The first primary electrode and the fourth primary electrode are electrically connectable or electrically connected to each other, and the first primary electrode and the fourth primary electrode are electrically connectable or electrically connected to each other. Primary area and second
One of the primary regions vibrates to increase the resonance excited by the other of the first primary region and the second primary region. As a result, on the primary side, the input electric energy can be more efficiently converted into mechanical elastic energy.

Further, according to the present invention, the first main surface and the second main surface facing each other, and the first and second end surfaces facing each other, the first main surface and the second main surface being opposite to each other. And a substantially rectangular parallelepiped piezoelectric substrate having first and second end surfaces orthogonal to the main surface of the substrate, and m (m is 1 or more and m is 1 or more) between the first and second end surfaces. A first primary region that divides a first direction substantially perpendicular to the first and second end faces; At least a second primary region and a secondary region, wherein the first primary region and the second primary region are adjacent to each other and the first primary region of the piezoelectric substrate Has a length that is approximately 1 / (2 m) of the length of the piezoelectric substrate in the first direction, and A first primary side electrode and a second primary side electrode are provided on the main surface and the second main surface of the first primary side electrode, respectively, and the first primary side electrode and the second primary side electrode of the first primary side region are provided. The two primary-side electrodes are polarized in a first predetermined direction in a second direction between the first main surface and the second main surface, and the second primary region of the piezoelectric substrate includes: 1 / (2) of the length of the piezoelectric substrate in the first direction
m) a third primary electrode and a fourth primary electrode facing each other on the first main surface and the second main surface of the second primary region, respectively, Provided between the third primary side electrode and the fourth primary side electrode in the second primary side region in a second predetermined direction opposite to the first predetermined direction in the second direction. Polarized in the direction
The first primary electrode and the third primary electrode are electrically connectable or electrically connected, and the second primary electrode and the fourth primary electrode are connected to each other. Are electrically connectable or electrically connected, and the distance g between the first primary electrode and the third primary electrode in the first direction is g.
And the distance g in the first direction between the second primary electrode and the fourth primary electrode is 20 times the thickness of the piezoelectric substrate between the first main surface and the second main surface. % And the distance between the first end face and the second end face is G
In this case, a third piezoelectric transformer is provided, wherein m / G is not more than G / (2 · m).

Thus, the distance g in the first direction between the first primary electrode and the third primary electrode and the second
The distance g in the first direction between the primary electrode and the fourth primary electrode in the first direction is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. Even if the first primary region and the second primary region that are adjacent to each other are simultaneously polarized in opposite directions, the first primary electrode and the third primary electrode that are adjacent to each other and that are provided on the first main surface. Discharge does not occur between the electrodes and between the second primary electrode and the fourth primary electrode adjacent to each other provided on the second main surface.

Further, the distance between the first end face and the second end face is m.
(M is 1 or more and an integral multiple of）) When driving can be performed so that a resonance mode of a wavelength is established, the distance g in the first direction between the first primary electrode and the third primary electrode and When the distance g between the second primary electrode and the fourth primary electrode in the first direction is G, the distance between the first end face and the second end face is G, For G, G / (2
By setting m or less, polarization is sufficiently performed even in the boundary region between the first primary region and the second primary region adjacent to each other, and as a result, piezoelectric vibration is sufficiently excited.

The resonance mode is determined by the input frequency to the primary electrode, the physical properties of the piezoelectric substrate, and the length in the vibration direction. Here, the length of 1 / (2 m) of the piezoelectric substrate in the first direction is equal to the resonance mode. This corresponds to a half wavelength of the mode. Therefore, for example, m is 1.5 if the resonance mode is 1.5 wavelengths, and 1 if the resonance mode is one wavelength. Since the resonance mode in the piezoelectric transformer can take any large wave number, m can be an integer of 1 or more.

In the third piezoelectric transformer of the present invention,
Since the third primary electrode and the fourth primary electrode are provided in addition to the first primary electrode and the second primary electrode,
The primary-side electrode area becomes larger, and the input impedance of the piezoelectric transformer decreases. As a result, electric energy is easily supplied from the power supply to the piezoelectric transformer.

Further, in the third piezoelectric transformer of the present invention, the first primary side region is approximately 1 / (2m) of the length of the piezoelectric substrate in the second direction (m is 1 or more and 1/2 of the length). Integer multiple)
Therefore, the first primary side region has a length of a half wavelength of the stress distribution at the time of resonance in the first direction of the piezoelectric substrate, and is positive or negative in the first direction at the time of resonance. This is a region of the piezoelectric substrate where any one of the negative stresses occurs.
Further, since the second primary region has a length of 1 / (2 m) or less of the length of the piezoelectric substrate in the second direction, the second primary region has a resonance in the first direction of the piezoelectric substrate. It is a region having a length equal to or less than a half wavelength of the stress distribution at the time, and at which one of positive and negative stress is generated in the first direction at the time of resonance.

The first primary side electrode and the second primary side electrode are provided on the first primary surface and the second primary surface of the first primary side region, respectively, so as to face each other, and the first primary side electrode is provided. A first primary surface and a second primary surface of the second primary region are polarized in a second direction between a first primary electrode and a second primary electrode of the region in a first direction. A third primary side electrode and a fourth primary side electrode are provided to face each other, and the third primary side electrode and the fourth primary side electrode in the second primary side region are arranged in the second direction in the second direction. Polarized in a second direction opposite to the first predetermined direction, and the first primary electrode and the third primary electrode are electrically connectable or electrically connected. , The second primary electrode and the fourth primary electrode are electrically connectable or electrically connected According to one of the first primary region and the second primary region, one of the first primary region and the second primary region depends on the direction of stress generated in the first primary region and the second primary region at the time of resonance. Side region and the other of the second primary region can be oscillated to increase the resonance excited by the other region, so that the input electrical energy on the primary side is more efficiently mechanically elastic energy Can be converted to

Preferably, in the second and third piezoelectric transformers, the second primary region is provided between the first primary region and the secondary region.

As described above, by providing the second primary region between the first primary region and the secondary region, the secondary region can be shortened in the first direction. When the secondary side is polarized in the first direction, the output impedance can be reduced. As the output impedance of the piezoelectric transformer decreases, the voltage that can be applied to the load connected to the secondary side of the piezoelectric transformer increases.

Also, by providing the second primary region between the first primary region and the secondary region, the secondary region can be shortened in the first direction, and the secondary region can be reduced. When polarization is performed in the first direction, the absolute voltage applied during polarization is smaller than when the second primary region is not provided. As a result, it is easy to take measures against high voltage, and it is possible to use a power supply for polarization at a lower voltage.

Further, when the load connected to the secondary side of the piezoelectric transformer is a cold cathode fluorescent lamp (CFL), it works more effectively. CFL requires a high voltage of 1 kV or more at the start of discharge. On the other hand, the step-up ratio of the piezoelectric transformer is proportional to Qm, which is the quality factor of the resonator. Before the discharge starts, the impedance of the CFL is close to infinity, so that the step-up ratio is proportional to Qm of the piezoelectric transformer itself.
The boost ratio can be increased. Therefore, even if the secondary region is shortened by providing the second primary region in this manner, and the boosting ratio determined by the shape of the secondary side becomes small, as described above, at the start of discharge, the resonance of the resonator itself is started. Since Qm greatly contributes to the boost ratio, boosting to a voltage at which discharge can be started can be easily performed. When the discharge starts, the impedance of the CFL decreases, but the output impedance of the piezoelectric transformer decreases as described above by providing such a second primary region, so that the voltage applied to the CFL increases accordingly. can do.

According to the present invention, the first and second main surfaces facing each other and the first and second main surfaces facing each other are also provided.
A substantially rectangular parallelepiped piezoelectric substrate having end surfaces of the first and second main surfaces and first and second end surfaces orthogonal to the first and second main surfaces. A plurality of primary regions and a plurality of secondary regions in this order from the first end surface side to the second end surface in a first direction substantially perpendicular to the end surface of the plurality of primary regions. A plurality of first primary electrodes respectively provided on the first main surface; and a plurality of first primary electrodes respectively provided on the second main surface of the plurality of primary regions in opposition to the first primary electrode. A plurality of second primary-side electrodes, and a resonance mode having a wavelength of n (n is 1 or more and an integral multiple of 1/2) stands between the first end face and the second end face. And at least one pair of the primary regions adjacent to each other among the primary regions of the plurality of primary regions. A distance g in the first direction between at least one pair of the first primary electrodes provided adjacent to each other on the main surface of the first surface, and a second distance of the at least one pair of the primary regions adjacent to each other. In the first direction between at least one pair of the second primary electrodes provided adjacent to each other on the main surface of
Is at least 20% of the thickness of the piezoelectric substrate between the first main surface and the second main surface, and the first end surface and the second
Where G is the distance between the end faces of
/ (2 · n) or less, connecting one of the at least one pair of adjacent first primary electrodes to one of a positive electrode and a negative electrode of a DC high-voltage power supply, The other of the at least one pair of the first primary electrodes adjacent to each other is connected to the other of the positive electrode and the negative electrode of the DC high-voltage power supply, and among the at least one pair of the second primary electrodes adjacent to each other, Connecting the second primary electrodes respectively corresponding to the one of the at least one pair of the first primary electrodes adjacent to each other to the other of the positive electrode and the negative electrode of the DC high-voltage power supply; Of the second primary electrodes adjacent to each other,
Connecting the second primary electrodes respectively corresponding to the other of the first primary electrodes adjacent to each other to the one of a positive electrode and a negative electrode of the DC high-voltage power supply; A step of simultaneously polarizing a pair of the primary regions adjacent to each other in directions opposite to each other in a thickness direction between the piezoelectric substrates between the first main surface and the second main surface. A method for manufacturing a piezoelectric transformer is provided.

As described above, the gap g in the first direction between the mutually adjacent first primary electrodes provided on the first main surfaces of the mutually adjacent primary regions, and the distance g in the first direction between the mutually adjacent primary regions. The distance g in the first direction between the second primary electrodes provided on the second main surface and adjacent to each other is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. Thereby, even if the primary regions adjacent to each other are simultaneously polarized in the opposite directions, even if the primary regions adjacent to each other are provided between the first primary electrodes adjacent to each other and the second primary region provided on the first main surface,
No discharge occurs between the adjacent second primary electrodes provided on the main surface of the first element.

Further, n is provided between the first end face and the second end face.
(N is 1 or more and an integral multiple of 1/2) When driving can be performed so that a resonance mode of a wavelength is established, first primary surfaces provided on the first main surfaces of the primary regions adjacent to each other are respectively provided. The distance g in the first direction between the side electrodes and the distance g in the first direction between the mutually adjacent second primary electrodes provided on the second main surfaces of the mutually adjacent primary regions, respectively, The distance between the first end face and the second end face is G
In this case, by setting G and (2 · n) or less with respect to n and G, polarization is sufficiently performed even in the boundary region between the primary regions adjacent to each other, and as a result, piezoelectric vibration is sufficiently excited. Is done.

The piezoelectric transformer manufactured as described above has a plurality of primary regions in a first direction substantially perpendicular to the first and second end faces, and includes a first end face and the second end face. N (n is 1 or more and an integral multiple of 1/2)
Since the piezoelectric transformer is drivable so that the resonance mode of the wavelength is set, each of the plurality of primary regions can be a region in which one of positive or negative stress is generated at the time of resonance. Since the adjacent primary regions are polarized in opposite directions in the thickness direction of the piezoelectric substrate between the first main surface and the second main surface, the adjacent primary regions are located on the first main surface of the adjacent primary regions. The first primary electrodes are connected in common, and the second primary regions adjacent to each other are connected to each other.
By commonly connecting the second primary electrodes on the main surfaces of the two, any one of the primary regions adjacent to each other increases the resonance of the piezoelectric substrate excited by the other of the primary regions adjacent to each other. Vibrates like so. As a result, on the primary side, the input electric energy can be more efficiently converted into mechanical elastic energy.

Further, according to the present invention, the first main surface and the second main surface facing each other, and the first and second end surfaces facing each other, the first main surface and the second main surface. Is a substantially rectangular parallelepiped piezoelectric substrate having first and second end surfaces orthogonal to the main surface of the first substrate, and a first direction that divides a first direction substantially perpendicular to the first and second end surfaces. At least a primary region, a second primary region, and a secondary region, the first primary region and the second primary region are adjacent to each other, and the first end surface and M between the second end face
(M is 1 or more and an integral multiple of 1/2) drivable so that a resonance mode of a wavelength is established, and the first primary side region is substantially 1 length of the length of the piezoelectric substrate in the first direction. / (2m)
A first primary electrode and a second primary electrode are provided on the first main surface and the second main surface of the first primary region, respectively, facing each other, The second primary region has a length equal to or less than 1 / (2 m) of a length of the piezoelectric substrate in the first direction, and the first primary surface of the second primary region and A third primary electrode and a fourth primary electrode are provided on the second main surface so as to face each other, and the first primary electrode and the third primary electrode are provided between the first primary electrode and the third primary electrode. The distance g in the direction and the distance g in the first direction between the second primary electrode and the fourth primary electrode are the same as the piezoelectric substrate between the first main surface and the second main surface. Is not less than 20% of the thickness of the first end face and the distance between the first end face and the second end face is G.
The first primary electrode and the fourth primary electrode are connected to one of a positive electrode and a negative electrode of a DC high-voltage power supply by using a piezoelectric substrate having G / (2 · m) or less for G and G. Connecting the second primary electrode and the third primary electrode to the other of the positive electrode and the negative electrode of the DC high-voltage power supply;
Between the first primary electrode and the second primary electrode in the primary region in a first predetermined direction in a second direction between the first main surface and the second main surface. And a second predetermined direction opposite to the first predetermined direction in the second direction between the third primary electrode and the fourth primary electrode in the second primary region. And a method of manufacturing a piezoelectric transformer.

Thus, the distance g in the first direction between the first primary electrode and the third primary electrode and the second
The distance g in the first direction between the primary electrode and the fourth primary electrode in the first direction is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface. Even if the first primary region and the second primary region that are adjacent to each other are simultaneously polarized in opposite directions, the first primary electrode and the third primary electrode that are adjacent to each other and that are provided on the first main surface. Discharge does not occur between the electrodes and between the second primary electrode and the fourth primary electrode adjacent to each other provided on the second main surface.

The distance between the first end face and the second end face is m.
(M is 1 or more and an integral multiple of）) When driving can be performed so that a resonance mode of a wavelength is established, the distance g in the first direction between the first primary electrode and the third primary electrode and When the distance g between the second primary electrode and the fourth primary electrode in the first direction is G, the distance between the first end face and the second end face is G, For G, G / (2
By setting m or less, polarization is sufficiently performed even in the boundary region between the first primary region and the second primary region adjacent to each other, and as a result, piezoelectric vibration is sufficiently excited.

Preferably, the first primary electrode and the third primary electrode are electrically connectable or electrically connected to each other, and the second primary electrode and the third primary electrode are connected to each other. And further comprising the step of electrically connecting or electrically connecting the primary electrode to the fourth primary electrode.

The piezoelectric transformer manufactured in this manner has the same function as the above-mentioned third transformer, and has a larger electrode area on the primary side and a smaller input impedance of the piezoelectric transformer. The point at which electric energy is easily supplied from the power source to the power source, and either one of the first primary side region and the second primary side region is the first primary side region.
Vibrating to increase the resonance excited by the primary region and the other region of the second primary region, so that the input electrical energy on the primary side can be more efficiently mechanically It is the same as the third transformer in that it can be converted into elastic energy.

Preferably, the second primary region is provided between the first primary region and the secondary region.

In the piezoelectric transformer manufactured as described above, the output impedance of the piezoelectric transformer can be reduced by providing the second primary region between the first primary region and the secondary region. The point that the voltage that can be applied to the load connected to the secondary side of the piezoelectric transformer can be increased, and the absolute voltage that is applied during the polarization of the secondary side can be reduced. As described above, the power supply of the present invention can be used at a lower voltage, and when the load connected to the secondary side of the piezoelectric transformer is a cold-cathode tube (CFL), it operates more effectively. It has the same function as the third transformer.

In these inventions, as described above, the lower limit of the distance between the adjacent electrodes on the primary side is 20% of the thickness of the piezoelectric substrate, and the upper limit is the distance between the first end face and the second end face, that is, the piezoelectric substrate. If the thickness of G is G and the wave number at which the resonance mode hits is k (= G / λ, λ is the wavelength), excitation can be generated if G / 2k. Further, G / 4k is more preferable because the excitation is further increased. G / 10
k is more preferable because the unpolarized region becomes smaller and the excitation efficiency becomes larger. Incidentally, the lower limit is considered to be due to the coercive electric field of the piezoelectric substrate material and the dielectric breakdown electric field of the atmosphere in which the polarization process is performed. Is particularly preferably 20% or more of the thickness.

[0040]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a view for explaining a piezoelectric transformer and a method of manufacturing the same according to a first embodiment of the present invention. FIG. 1 (A) is a perspective view and FIG. 1
1B is a cross-sectional view, FIG. 1C is a view showing a stress distribution, FIG.
FIG. 1D is a diagram showing an amplitude distribution, and FIGS. 1E and 1F are cross-sectional views for explaining a polarization method.

Upper surface 212 of piezoelectric ceramic substrate 210
A primary-side electrode 222 is provided on about one-third of the left side, and a primary-side electrode 224 is also provided on the lower surface 214 of the piezoelectric ceramic substrate 210 so as to face the primary-side electrode 222. On the upper surface 212 of the piezoelectric ceramic substrate 210, the longitudinal direction L of the piezoelectric ceramic substrate 210 extends from the primary side end surface 216.
From the primary side electrode 216 to a position approximately ／ of the length in the longitudinal direction L of the piezoelectric ceramic substrate 210 from the primary electrode 2 to the primary electrode 2.
26, the primary electrode 228 is also provided on the lower surface 214 of the piezoelectric ceramic substrate 210 so as to face the primary electrode 226.
Is provided. The primary electrode 222 is the primary electrode 22
6, and the primary electrode 224 is spaced apart from the primary electrode 228.

The piezoelectric ceramic substrate 210 between the primary electrode 222 and the primary electrode 224 is polarized upward in the thickness direction T. The piezoelectric ceramic substrate 210 between the primary electrode 226 and the primary electrode 228 is polarized downward in the thickness direction T.

A secondary electrode 242 is provided on the upper surface 212 near the secondary end surface 217, and a secondary electrode 244 is provided on the lower surface 214 near the secondary end surface 217. The secondary region d of the piezoelectric ceramic substrate 210 is polarized leftward in the longitudinal direction L, which is the direction in which the upper surface 212 and the lower surface 214 extend.

The primary electrodes 222, 224, 22
6, 228 and the secondary electrodes 242, 244 extend from the longitudinal end face 218 to the longitudinal end face 219.
Extending over the entire width in the width direction W.

The primary electrodes 222 and 226 are connected to one end of a power supply 80, the other end of the power supply 80 is connected to primary electrodes 224 and 228 and one end of a CFL 90 as a load, and the other end of the CFL 90 is connected to a secondary electrode. 242.

The piezoelectric transformer 10 according to the present embodiment is provided between the primary end face 216 and the secondary end face 217, for example, as follows.
It can be driven so that a vibration mode of five wavelengths is set. In this case, １ ／, ／, and の of the length of the longitudinal direction L of the piezoelectric ceramic substrate 210 from the primary side end surface 216 are nodes of the longitudinal vibration. In the piezoelectric transformer 10, the left side 2
/ 3 is the primary side area a, and 1/3 on the right side is the secondary side area b.

In the present embodiment, first, FIG.
As shown in (A), the primary electrodes 222 and 226 and the secondary electrodes 24 are formed on the upper surface 212 of the piezoelectric ceramic substrate 210.
2 are formed, and primary electrodes 224, 228,
The secondary electrode 244 is formed.

Next, as shown in FIG. 1E, the primary electrodes 224 and 226 are connected to the positive electrode of the DC high-voltage power supply 271, and the primary electrodes 222 and 228 are connected to the negative electrode of the DC high-voltage power supply 271. Upward polarization in the thickness direction T of the piezoelectric ceramic substrate 210 between the electrode 222 and the primary electrode 224, and downward polarization in the thickness direction T of the piezoelectric ceramic substrate 210 between the primary electrode 226 and the primary electrode 228. And at the same time.

Thereafter, as shown in FIG. 1 (F), the positive electrodes of the DC high-voltage power supply 272 have secondary electrodes 242 and 244, and the negative electrodes of the DC high-voltage power supply 272 have primary electrodes 222, 224 and 242.
26 and 228 are connected to perform leftward polarization in the longitudinal direction L of the piezoelectric ceramic substrate 210 between the primary electrodes 226 and 228 and the secondary electrodes 242 and 244.

In the present embodiment, the primary electrode 22
The length g of the longitudinal direction L of the piezoelectric ceramic substrate 210 in the gap 251 between the second electrode 226 and the primary electrode 226 and the longitudinal direction L of the piezoelectric ceramic substrate 210 in the gap 252 between the primary electrode 224 and the primary electrode 228. Is set to 20% or more of the thickness t of the piezoelectric ceramic substrate 210, the upward polarization in the thickness direction T of the piezoelectric ceramic substrate 210 between the primary side electrode 222 and the primary side electrode 224, and the primary side Even if the downward polarization in the thickness direction T of the piezoelectric ceramic substrate 210 between the electrode 226 and the primary electrode 228 is performed simultaneously, the gap 251 and the primary electrode 22 between the primary electrode 222 and the primary electrode 226 can be obtained.
No discharge occurs in the gap 252 between the electrode 4 and the primary electrode 228.

Specifically, when a polarization treatment is performed in silicone oil, when a polarization voltage of 1.5 kV is applied to a thickness (t) of 1 mm, 1.5 V / mm is applied in the thickness direction.
Is applied. At this time, if the length g of the gaps 251 and 252 is smaller than 0.1 mm, the electric field applied to the gaps 251 and 252 becomes larger than 15 kV / mm, and discharge occurs. If the gap is 0.20 mm or more, no discharge occurs.

The polarization is preferably performed in a silicone oil having an excellent insulating property, and the temperature of the polarization is preferably 80 ° C. to 150 ° C.

The piezoelectric transformer 10 according to the present embodiment
Can be driven between the primary end face 216 and the secondary end face 217 so that, for example, a vibration mode of 1.5 wavelengths is set up, so that the distance between the first and second end faces is G. Void 251 between primary electrode 222 and primary electrode 226
The length g of the piezoelectric ceramic substrate 210 in the longitudinal direction L and the length g of the gap 252 between the primary electrode 224 and the primary electrode 228 in the longitudinal direction L of the piezoelectric ceramic substrate 210 are from 0.20 mm to G / 3. Accordingly, the polarization is sufficiently polarized even in the boundary region between the piezoelectric ceramic substrate 210 between the primary electrodes 222 and 224 and the piezoelectric ceramic substrate 210 between the primary electrodes 226 and 228. As a result, the piezoelectric vibration is sufficiently excited.

In the piezoelectric transformer 10, between the primary electrodes 222 and 224 and the primary electrodes 226 and 228
When a voltage is applied therebetween, an electric field is applied in the thickness direction T in the primary side region a, and longitudinal vibration in the longitudinal direction L is excited by a piezoelectric transverse effect displaced in a direction perpendicular to the polarization direction, and the piezoelectric transformer 10 The whole vibrates. Further, on the secondary side, a mechanical strain is generated in the longitudinal direction L, and a potential difference is generated in the polarization direction, so that the secondary electrodes 242, 244 to the primary electrodes 222, 224 and the primary electrodes 226, 228
A voltage having the same frequency as the primary voltage applied therebetween is extracted. When a drive voltage having a frequency equal to the resonance frequency of the piezoelectric transformer 10 is applied between the primary electrodes 222 and 224 and between the primary electrodes 226 and 228, a very high step-up ratio can be obtained.

Further, in this piezoelectric transformer 10,
Since the primary-side electrode 226 and the primary-side electrode 228 are provided in addition to the primary-side electrode 222 and the primary-side electrode 224, the primary-side electrode area becomes larger, and the piezoelectric transformer 10
Input impedance becomes small. As a result, electric energy is easily supplied from the power supply 80 to the piezoelectric transformer 10.

Further, the primary electrode 222 and the primary electrode 2
24, the piezoelectric ceramic substrate 210 has a thickness direction T
, The piezoelectric ceramic substrate 210 between the primary electrode 226 and the primary electrode 228 is polarized downward in the thickness direction T, and the primary electrodes 222 and 226 are connected in common, and the primary electrode 224 and Since the 228 is connected in common, the resonance of the entire piezoelectric ceramics substrate 210 excited by the piezoelectric ceramics substrate 210 between the primary side electrode 222 and the primary side electrode 224 and the primary side electrode 226 and the primary side electrode 228 The resonance of the entire piezoelectric ceramic substrate 210 which is excited by the piezoelectric ceramic substrate 210 during the period increases the other resonance with each other. Therefore, the input electric energy can be more efficiently converted into mechanical elastic energy on the primary side.

The primary electrodes 226 and 228 are provided between the primary electrodes 222 and 224 and the secondary electrodes 242 and 244.

By providing the primary electrodes 226 and 228 in this manner, the secondary region b can be shortened in the longitudinal direction L, and as a result, the output impedance of the piezoelectric transformer 10 can be reduced. When the output impedance of the piezoelectric transformer 10 decreases, the voltage that can be applied to the load (CFL) 90 connected to the secondary side of the piezoelectric transformer 10 increases.

Further, by providing the primary electrodes 226 and 228 in this manner, the secondary region b can be moved in the longitudinal direction L.
When the secondary region b is polarized in the longitudinal direction L, the absolute voltage applied during polarization is smaller than when the primary electrodes 226 and 228 are not provided. As a result, it is easy to take measures against high voltage, and it is possible to use a power supply for polarization at a lower voltage.

Further, when the load connected to the secondary side of the piezoelectric transformer 10 is the CFL 90, the present embodiment operates more effectively. CFL is 1k at the start of discharge.
A high voltage of V or more is required. On the other hand, the step-up ratio of the piezoelectric transformer 10 is proportional to Qm which is the quality factor of the resonator. Before the start of discharge, the impedance of the CFL 90 is close to infinity, so that the step-up ratio is proportional to Qm of the piezoelectric transformer 10 itself, and the step-up ratio can be increased. Therefore, by providing the primary electrodes 226 and 228 in this way, even if the secondary region b is shortened and the boost ratio determined by the shape of the secondary becomes small, the Qm of the resonator itself increases at the start of discharge. Since this greatly contributes to the ratio, the voltage can be easily increased to a voltage at which discharge can be started. When the discharge starts, the impedance of the CFL 90 decreases, but the output impedance of the piezoelectric transformer 10 decreases by providing the primary electrodes 226 and 228 in this manner. Therefore, the voltage applied to the CFL 90 must be increased accordingly. Can be.

(Second Embodiment) FIG. 2 is a view for explaining a piezoelectric transformer and a method of manufacturing the same according to a second embodiment of the present invention. FIG. 2 (A) is a perspective view and FIG. 2
2B is a cross-sectional view, FIG. 2C is a view showing a stress distribution, FIG.
2D is a diagram showing an amplitude distribution, and FIGS. 2E and 2F are cross-sectional views for explaining a polarization method.

Upper surface 312 of piezoelectric ceramic substrate 310
A primary electrode 321 is provided on about 1/4 of the left side, and a primary electrode 322 is also provided on the lower surface 314 of the piezoelectric ceramic substrate 310 so as to face the primary electrode 321. On the upper surface 312 of the piezoelectric ceramic substrate 310, the longitudinal direction L of the piezoelectric ceramic substrate 310 extends from the primary end surface 316.
From the primary side electrode 316 to a position away from the primary end surface 316 by approximately ／ of the length of the piezoelectric ceramic substrate 310 in the longitudinal direction L.
23, and the primary electrode 324 is also provided on the lower surface 314 of the piezoelectric ceramic substrate 310 so as to face the primary electrode 323.
Is provided. The primary electrode 323 is the primary electrode 32
1, and the primary electrode 324 is provided separately from the primary electrode 322. On the upper surface 312 of the piezoelectric ceramic substrate 310, the length from the primary end surface 316 to the length L in the longitudinal direction of the piezoelectric ceramic substrate 310 is about ２.
, A primary side electrode 325 is provided from the primary side end surface 316 to a position away from the primary side end surface 316 by about 約 of the length of the piezoelectric ceramic substrate 310 in the longitudinal direction L,
The piezoelectric ceramic substrate 31 faces the primary electrode 325.
The primary electrode 326 is also provided on the lower surface 314 of the zero. The primary electrode 325 is provided separately from the primary electrode 321, and the primary electrode 326 is provided separately from the primary electrode 324.

The piezoelectric ceramic substrate 310 between the primary electrode 321 and the primary electrode 322 is polarized upward in the thickness direction T. The piezoelectric ceramic substrate 310 between the primary side electrode 323 and the primary side electrode 324 is polarized downward in the thickness direction T. Primary electrode 32
Piezoelectric ceramic substrate 3 between electrode 5 and primary electrode 326
10 is polarized upward in the thickness direction T.

A secondary electrode 342 is provided on an upper surface 312 near the secondary end surface 317, and a secondary electrode 344 is provided on a lower surface 314 near the secondary end surface 217. The secondary region d of the piezoelectric ceramic substrate 310 is polarized leftward in the longitudinal direction L, which is the direction in which the upper surface 312 and the lower surface 314 extend.

The primary electrodes 321 to 326 and the secondary electrodes 342 and 344 extend from the longitudinal end face 318 to the longitudinal end face 319 over the entire width of the piezoelectric substrate 310 in the width direction W.

The primary electrodes 321, 323 and 325 are connected to one end of a power supply 80, and the other end of the power supply 80 is connected to the primary electrodes 322, 324 and 326 and a C as a load.
The other end of the CFL 90 is connected to the secondary electrode 342.

The piezoelectric transformer 20 of the present embodiment can be driven such that a vibration mode of, for example, two wavelengths is set between the primary end face 316 and the secondary end face 317. In this case, ８, ／, ／ of the length in the longitudinal direction L of the piezoelectric ceramic substrate 310 from the primary side end surface 316.
And 7/8 are nodes of vibration in the longitudinal direction L, respectively. In the piezoelectric transformer 20, 3/4 on the left is the primary region c, and 1/4 on the right is the secondary region d.

In the present embodiment, first, FIG.
As shown in (A), primary electrodes 321, 323, and 325 and a secondary electrode 342 are formed on an upper surface 312 of a piezoelectric ceramic substrate 310, and a primary electrode 322 is formed on a lower surface 314.
324, 326 and the secondary electrode 344 are formed.

Next, as shown in FIG. 2 (E), primary electrodes 322, 323, 32
6. The primary electrodes 321 and 3 are connected to the negative electrode of the DC high-voltage power supply 371.
24, 325, the polarization of the piezoelectric ceramic substrate 310 in the thickness direction T between the primary electrode 321 and the primary electrode 322, and the piezoelectric ceramic between the primary electrode 323 and the primary electrode 324. The piezoelectric ceramic substrate 310 between the downward polarization in the thickness direction T of the substrate 310 and the primary electrode 325 and the primary electrode 326.
And upward polarization in the thickness direction T at the same time.

Then, as shown in FIG. 2F, the secondary electrodes 342 and 344 are connected to the positive electrode of the DC high-voltage power supply 372, and the primary electrodes 321 to 326 are connected to the negative electrode of the DC high-voltage power supply 372. Electrodes 325, 326 and secondary electrode 34
2 and 344, a leftward polarization in the longitudinal direction L of the piezoelectric ceramic substrate 310 is performed.

In this embodiment, the primary electrode 32
The length g of the gap 351 between the first electrode 323 and the primary electrode 323 in the longitudinal direction L of the piezoelectric ceramic substrate 310,
The length g of the longitudinal direction L of the piezoelectric ceramic substrate 310 in the gap 352 between the electrode 22 and the primary electrode 324, and the length L of the piezoelectric ceramic substrate 310 in the gap 353 between the primary electrode 323 and the primary electrode 325. And the length g of the gap 354 between the primary side electrode 324 and the primary side electrode 326 in the longitudinal direction L of the piezoelectric ceramic substrate 310,
Since the thickness t is set to 20% or more of the thickness t of the piezoelectric ceramic substrate 310, an upward polarization in the thickness direction T of the piezoelectric ceramic substrate 310 between the primary electrode 321 and the primary electrode 322, and the primary electrode 323 and the primary electrode 324
Of the piezoelectric ceramic substrate 310 in the thickness direction T between the primary electrode 325 and the primary electrode 3.
26 in the thickness direction T of the piezoelectric ceramic substrate 310
, The gap 351 between the primary side electrode 321 and the primary side electrode 323, the gap 352 between the primary side electrode 322 and the primary side electrode 324, and the primary side electrode 323 and the primary side. Gap 353 between electrode 325
No discharge occurs in the gap 354 between the primary electrode 324 and the primary electrode 326.

The polarization is preferably performed in a silicone oil having excellent insulation properties, and the temperature of the polarization is preferably 80 ° C. to 150 ° C.

The piezoelectric transformer 20 according to the present embodiment
Can be driven between the primary side end surface 316 and the secondary side end surface 317 so that, for example, a vibration mode of two wavelengths is set up. Therefore, the gap 351 between the primary side electrode 321 and the primary side electrode 323 is formed. The length g of the piezoelectric ceramic substrate 310 in the longitudinal direction L, the length g of the gap 352 between the primary electrode 322 and the primary electrode 324 in the longitudinal direction L of the piezoelectric ceramic substrate 310, the primary electrode 323 and the primary electrode A gap 354 between the primary side electrode 324 and the primary side electrode 326, where g is the length of the gap 353 between the primary electrode 324 and the length L of the piezoelectric ceramic substrate 310 in the longitudinal direction, G is the length of the piezoelectric substrate, and t is the thickness By setting the length g of the piezoelectric ceramic substrate 310 in the longitudinal direction L from 0.2 t to G / 4, the piezoelectric ceramic substrate 310 between the primary side electrode 321 and the primary side electrode 322 can be The boundary region between the piezoelectric ceramics substrate 210 between the primary-side electrode 323 and the primary-side electrode 324, and the primary-side electrode 323 and the primary-side electrode 3
24 is sufficiently polarized also in the boundary region between the piezoelectric ceramic substrate 310 between the primary electrode 325 and the primary ceramic electrode 210 between the primary electrode 325 and the primary electrode 326. As a result, the piezoelectric vibration is sufficiently excited. You.

In the piezoelectric transformer 20, when a voltage is applied between the primary electrodes 321 and 322, between the primary electrodes 323 and 324, and between the primary electrodes 325 and 326, in the primary region c, the thickness direction T An electric field is applied to the piezoelectric element, and the piezoelectric element is displaced in a direction perpendicular to the polarization direction.
Is excited, and the entire piezoelectric transformer 20 vibrates. Further, on the secondary side, a mechanical strain is generated in the longitudinal direction L, and a potential difference is generated in the polarization direction, so that the secondary electrodes 342 and 344 are separated from the primary electrodes 321 and 322 by the piezoelectric longitudinal effect.
, Between the primary electrodes 323 and 324 and the primary electrode 32
A voltage having the same frequency as the primary voltage applied between 5, 326 is extracted. When a drive voltage having a frequency equal to the resonance frequency of the piezoelectric transformer 20 is applied to the primary electrode, a very high boosting ratio can be obtained.

In the piezoelectric transformer 20,
Since the primary electrodes 323 to 326 are provided in addition to the primary electrode 321 and the primary electrode 322, the primary electrode area becomes larger and the input impedance of the piezoelectric transformer 20 becomes smaller. As a result, electric energy is easily supplied from the power supply 80 to the piezoelectric transformer 10.

Further, the primary electrode 321 and the primary electrode 3
22 between the piezoelectric ceramic substrate 310 and the thickness direction T.
And the piezoelectric ceramic substrate 310 between the primary electrode 323 and the primary electrode 324 is polarized downward in the thickness direction T, and the piezoelectric ceramic substrate 310 between the primary electrode 325 and the primary electrode 326 is polarized downward.
Is polarized upward in the thickness direction T, and the primary side electrode 3
21, 323 and 325 are connected in common and the primary electrodes 322, 324 and 326 are connected in common, so that the piezoelectric material excited by the piezoelectric ceramic substrate 310 between the primary electrode 321 and the primary electrode 322. The resonance of the entire ceramic substrate 310 and the piezoelectric ceramic substrate 310 between the primary electrode 323 and the primary electrode 324
The resonance of the entire piezoelectric ceramic substrate 310 excited by the piezoelectric ceramic substrate 310 and the resonance of the entire piezoelectric ceramic substrate 310 excited by the piezoelectric ceramic substrate 310 between the primary electrode 325 and the primary electrode 326 increase other resonances with each other. . Therefore, the input electric energy can be more efficiently converted into mechanical elastic energy on the primary side.

Since the primary electrodes 323 to 326 are provided between the primary electrodes 321 and 322 and the secondary electrodes 342 and 344, the output impedance of the piezoelectric transformer 20 can be reduced, and the The voltage that can be applied to the load (CFL) 90 connected to the secondary side of the power supply becomes large.

Further, by providing the primary electrodes 323 to 326 in this manner, the secondary region d can be shortened in the longitudinal direction L, and when the secondary region b is polarized in the longitudinal direction L, the polarization can be reduced. In this case, the absolute voltage to be applied is reduced, and as a result, a countermeasure against a high voltage becomes easy, and a power supply for polarization can be used with a lower voltage.

Further, when the load connected to the secondary side of the piezoelectric transformer 10 is the CFL 90, the present embodiment operates more effectively, similarly to the first embodiment.

[0081]

According to the present invention, even if a piezoelectric transformer having a structure in which a plurality of primary regions are arranged and adjacent primary regions are polarized in directions opposite to each other is manufactured by a small number of polarization processing steps, No discharge occurs between adjacent primary electrodes, and the piezoelectric transformer manufactured according to the present invention is:
This is a piezoelectric transformer having excellent characteristics in which the polarization is sufficient and the piezoelectric vibration is sufficiently excited. Thus, according to the present invention,
Piezoelectric transformers with excellent characteristics can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a piezoelectric transformer according to a first embodiment of the present invention and a method for manufacturing the same, and FIG.
1 is a perspective view, FIG. 1B is a cross-sectional view, FIG. 1C shows a stress distribution, FIG. 1D shows an amplitude distribution, and FIG.
(E) and FIG. 1 (F) are cross-sectional views.

FIG. 2 is a diagram for explaining a piezoelectric transformer and a method of manufacturing the same according to a second embodiment of the present invention.
2 is a perspective view, FIG. 2B is a cross-sectional view, FIG. 2C shows a stress distribution, FIG. 2D shows an amplitude distribution, and FIG.
(E) and FIG. 2 (F) are cross-sectional views.

[Explanation of symbols]

10, 20: Piezoelectric transformer 80: Power supply 90: Load (cold cathode tube: CFL) 210, 310: Piezoelectric ceramic substrate 212, 312: Upper surface 214, 314: Lower surface 216, 316: Primary end surface 217, 317: Secondary side End faces 218, 219, 318, 319 ... End faces in the longitudinal direction 222, 224, 226, 228, 321-326 ... Primary electrodes 242, 244, 342, 344 ... Secondary electrodes 251, 252, 351-354 ... Voids 271, 272, 371, 372 High-voltage direct-current power supply for polarization a, c: Primary region b, d: Secondary region t: Thickness of piezoelectric ceramic substrate g: Length of void in longitudinal direction W: Width direction T: Thickness Direction L: longitudinal direction

Claims (8)

[Claims] A first and a second main surface facing each other;
First and second end faces facing each other, wherein
And the first and second planes orthogonal to the second main plane
And a substantially rectangular parallelepiped piezoelectric substrate having a first end face and a second end face in a first direction substantially perpendicular to the first and second end faces. A piezoelectric substrate having a plurality of primary regions and a secondary region in this order; a plurality of first primary electrodes provided on the first main surface of the plurality of primary regions, respectively; The second side of the plurality of primary side regions respectively facing the primary side electrodes.
And a plurality of second primary electrodes respectively provided on the main surface of the first primary region and at least one pair of the primary regions adjacent to each other among the plurality of primary regions is the first main surface and the Polarized in opposite directions in the thickness direction of the piezoelectric substrate between the second main surfaces, and n (n is 1 or more and an integral multiple of 1/2) between the first end surface and the second end surface. A piezoelectric transformer drivable so that a wavelength resonance mode is established, wherein the piezoelectric transformers are provided on the first main surfaces of the at least one pair of the adjacent primary regions, respectively, between the first primary electrodes adjacent to each other. In the first direction, and the first direction between the adjacent second primary electrodes provided on the second main surface of the at least one pair of adjacent primary regions, respectively. Is g The thickness of the piezoelectric substrate between the first main surface and the second main surface is at least 20% of the thickness of the piezoelectric substrate, and the distance between the first end surface and the second end surface is G, A piezoelectric transformer, wherein G is not more than G / (2 · n). 2. A first main surface and a second main surface facing each other, and first and second end surfaces facing each other, which are orthogonal to the first main surface and the second main surface. A substantially rectangular parallelepiped piezoelectric substrate having first and second end faces, and n (n is 1 or more and an integral multiple of 1/2) between the first end face and the second end face. A) a first primary region and a second primary region separated from each other in a first direction substantially perpendicular to the first and second end faces, the piezoelectric transformer being drivable so that a resonance mode of a wavelength is established; At least a region and a secondary region, wherein the first primary region and the second primary region are adjacent to each other, and wherein the first primary region has the resonance in the first direction. Having a length of approximately half a wavelength of the stress distribution at the time of the resonance and having a positive or negative The first primary side electrode and the second primary side electrode are located on the first primary side region and the second primary side surface of the first primary side region, respectively. A second direction between the first main surface and the second main surface provided between the first primary side electrode and the second primary side electrode in the first primary side region; Wherein the second primary side region has a length equal to or less than half a wavelength of the stress distribution at the time of the resonance in the first direction and the first direction at the time of the resonance. Where the other of the positive and negative stresses is opposite to the one stress, and the first primary surface and the second primary surface of the first primary region have a third primary side. An electrode and a fourth primary electrode are provided to face each other, and the second primary region The third primary electrode and the fourth primary electrode are polarized in the second direction in a second predetermined direction opposite to the first predetermined direction in the second direction, and the first primary electrode is And the third primary electrode are electrically connectable or electrically connected, and the second primary electrode and the fourth primary electrode are electrically connectable. A piezoelectric transformer that is or is electrically connected to the first primary electrode and the third primary electrode; the distance g in the first direction between the first primary electrode and the third primary electrode; and the second primary electrode and the second primary electrode. The distance g between the primary electrodes in the first direction is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface, and the distance g between the first end surface and the first end surface is When the distance between the second end faces is G, G / (2 · n) or less A piezoelectric transformer, characterized by being below. 3. A first main surface and a second main surface facing each other, and first and second end surfaces facing each other, which are orthogonal to the first main surface and the second main surface. A substantially rectangular parallelepiped piezoelectric substrate having first and second end faces, wherein m (m is 1 or more and an integral multiple of 1/2) between the first end face and the second end face; A) a piezoelectric transformer drivable so that a resonance mode of a wavelength is established, wherein a first primary region and a second primary region dividing a first direction substantially perpendicular to the first and second end faces; And at least a secondary region, wherein the first primary region and the second primary region are adjacent to each other, and wherein the first primary region of the piezoelectric substrate is The first main surface and the second main surface of the first primary region have a length substantially 1 / (2 m) of the length in the first direction.
A first primary side electrode and a second primary side electrode are provided on the main surface of the first primary side electrode so as to face each other, and a first primary side electrode and a second primary side electrode in the first primary side region are provided between Are polarized in a first direction in a second direction between the first main surface and the second main surface, and the second primary region of the piezoelectric substrate is The first primary surface and the second primary surface of the second primary region have a length of 1 / (2 m) or less of the length of the first direction, and a third primary electrode and a third primary electrode are provided. Four primary electrodes are provided to face each other, and the distance between the third primary electrode and the fourth primary electrode in the second primary region is the first predetermined value in the second direction. The first primary electrode and the third primary electrode are electrically connected to each other. A piezoelectric transformer that is capable or electrically connected, and wherein the second primary electrode and the fourth primary electrode are electrically connectable or electrically connected, The distance g in the first direction between the first primary electrode and the third primary electrode and the distance g in the first direction between the second primary electrode and the fourth primary electrode. g is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface, and the distance between the first end surface and the second end surface is G, A piezoelectric transformer, wherein G / (2 · m) or less for m and G. 4. The piezoelectric transformer according to claim 2, wherein said second primary region is provided between said first primary region and said secondary region. 5. A first and second main surface facing each other,
First and second end faces facing each other, wherein
And the first and second planes orthogonal to the second main plane
And a substantially rectangular parallelepiped piezoelectric substrate having a first end face and a second end face in a first direction substantially perpendicular to the first and second end faces. A plurality of primary regions and a secondary region in this order, a plurality of first primary electrodes provided on the first main surface of the plurality of primary regions, respectively, The second electrodes of the plurality of primary regions are respectively opposed to side electrodes.
And a plurality of second primary electrodes respectively provided on the main surfaces of the first and second surfaces, and n (n is 1 or more and an integral multiple of 1/2) between the first end surface and the second end surface. At least one of a plurality of primary regions provided adjacent to each other on the first main surfaces of the at least one pair of adjacent primary regions among the plurality of primary regions. The distance g between the pair of first primary electrodes in the first direction and at least one pair of the first primary electrodes adjacent to each other on the second main surface of the at least one pair of adjacent primary regions. The distance g between the pair of second primary electrodes in the first direction is not less than 20% of the thickness of the piezoelectric substrate between the first main surface and the second main surface; When the distance between the first end face and the second end face is G, n and G
Using a piezoelectric substrate that is not more than G / (2 · n) with respect to one of the at least one pair of adjacent first primary electrodes to one of a positive electrode and a negative electrode of a DC high-voltage power supply. Connecting the other of the at least one pair of the first primary electrodes adjacent to each other to the other of the positive electrode and the negative electrode of the DC high-voltage power supply; and the at least one pair of the second primary electrodes adjacent to each other. Connecting the second primary electrodes respectively corresponding to the one of the first primary electrodes adjacent to each other to the other of the positive electrode and the negative electrode of the DC high-voltage power supply, The second primary side of the at least one pair of the second primary electrodes adjacent to each other corresponds to the other one of the at least one pair of the first primary electrodes adjacent to each other. An electrode is connected to the one of the positive electrode and the negative electrode of the DC high-voltage power supply, and the at least one pair of adjacent primary regions is connected to the piezoelectric substrate between the first main surface and the second main surface. A method for manufacturing a piezoelectric transformer, comprising simultaneously polarizing in opposite directions in a thickness direction between the piezoelectric transformers. 6. A first main surface and a second main surface facing each other, and first and second end surfaces facing each other, which are orthogonal to the first main surface and the second main surface. A substantially rectangular parallelepiped piezoelectric substrate having first and second end surfaces, wherein a first primary region and a first primary region that divide a first direction substantially perpendicular to the first and second end surfaces are provided. A first primary region and a second primary region, the first primary region and the second primary region are adjacent to each other, and the first end surface and the second end surface are adjacent to each other. The first primary side region can be driven so that a resonance mode having a wavelength of m (m is 1 or more and an integral multiple of １ ／) stands between the first primary side region and the length of the piezoelectric substrate in the first direction. And has a length of about 1 / (2 m) of the first primary side electrode and the first primary side electrode and the second primary side of the first primary side region. And a second primary side electrode are provided facing each other, and the second primary side region has a length of 1 / (2 m) or less of a length of the piezoelectric substrate in the first direction. A third primary electrode and a fourth primary electrode are provided on the first main surface and the second main surface of the second primary region, respectively, so as to face each other; The distance g between the side electrode and the third primary electrode in the first direction and the distance g between the second primary electrode and the fourth primary electrode in the first direction are the same as When the distance between the first end surface and the second end surface is G, which is 20% or more of the thickness of the piezoelectric substrate between the first main surface and the second main surface, m and G On the other hand, by using a piezoelectric substrate of G / (2 · m) or less, the first primary electrode and the fourth primary electrode are connected to each other. Connecting the second primary electrode and the third primary electrode to the other of the positive electrode and the negative electrode of the DC high voltage power supply, and connecting the first primary electrode and the third primary electrode to the other of the positive electrode and the negative electrode of the DC high voltage power supply. Polarizing between the first primary electrode and the second primary electrode in a side region in a first direction in a second direction between the first main surface and the second main surface. Polarizing between the third primary electrode and the fourth primary electrode in the second primary region in a second predetermined direction opposite to the first predetermined direction in the second direction. And a step of manufacturing the piezoelectric transformer. 7. The first primary electrode and the third primary electrode are electrically connectable or electrically connected to each other, and the second primary electrode and the fourth primary electrode are electrically connected to each other. 7. The method according to claim 6, further comprising the step of electrically connecting or electrically connecting the side electrodes. 8. The piezoelectric transformer according to claim 6, wherein the second primary region is provided between the first primary region and the secondary region. Method.