JP2850216B2 - Piezoelectric transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric transformer, and more particularly to a cold cathode fluorescent lamp (hereinafter, CF) used for a backlight of a liquid crystal display (LCD) panel.
It is called L. The present invention relates to a piezoelectric transformer suitably used for lighting or the like.

[0002]

2. Description of the Related Art In portable equipment such as a notebook personal computer on which an LCD panel is mounted, miniaturization and power saving are demanded. A CFL widely used as a backlight of this LCD panel requires a high voltage of 1 kV or more at the start of lighting, and a high voltage of several hundred volts at the time of continuous lighting. A high step-up winding transformer has been used as a transformer for this purpose, but it is approaching the limit of high performance in terms of efficiency, size, and the like.

In recent years, for this LCD panel, a CFL lighting unit using a piezoelectric transformer capable of realizing smaller size and higher efficiency has been developed (Nikkei Electronics, 1
9944.11.7 (No. 621) 147 pages to 1st
See page 57. ). The piezoelectric transformer used here has a structure called a ROSEN type, and the step-up ratio is still insufficient. Therefore, in a practically used CFL lighting unit, a winding transformer is provided in front of the piezoelectric transformer. Was.

FIG. 27 is a view for explaining a conventional ROSEN type piezoelectric transformer, FIG. 27A is a perspective view, and FIG.
B is a cross-sectional view, FIG. 27C is a diagram showing a stress distribution, and FIG. 27D is a diagram showing an amplitude distribution.

A primary electrode 22 is provided on the left (primary) half of the upper surface 12 of the rectangular parallelepiped piezoelectric ceramic substrate 10, and a primary electrode 24 is also provided on the lower surface 14 of the piezoelectric ceramic substrate 10 so as to face the primary electrode 22. The piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24 is polarized in the thickness direction between the upper surface 12 and the lower surface 14.
A secondary electrode 72 is provided on a secondary end face 18 perpendicular to the upper surface 12 and the lower surface 14, and the piezoelectric ceramic substrate 10 between the primary electrodes 22, 24 and the secondary electrode 24 extends from the upper surface 12 and the lower surface 14. Polarized in the longitudinal direction, which is the direction. One end of the power supply 82 is connected to the primary electrode 22 via the connection section 122, and the other end is connected to the primary electrode 24 via the connection section 124. The secondary electrode 72 is connected to one end of a CFL 90 as a load, and the other end of the CFL 90 is connected to the primary electrode 24 via a connection 126.

When a voltage is applied between the primary electrodes 22 and 24 from the power source 82, an electric field is applied in the thickness direction in the left half, and the longitudinal vibration in the longitudinal direction is caused by the piezoelectric transverse effect displaced in the direction perpendicular to the polarization direction. When excited, the entire piezoelectric transformer 100 vibrates. Further, in the right half, mechanical strain occurs in the longitudinal direction, and a potential difference occurs in the polarization direction.
A voltage having the same frequency as the primary voltage applied between the primary electrodes 22 and 24 is extracted from the secondary electrode 72. When a driving voltage having a frequency equal to the resonance frequency of the piezoelectric transformer 100 is applied between the primary electrodes 22 and 24, a very high boosting ratio can be obtained.

[0007]

However, for example, PZ
In order to use a piezoelectric transformer using T (lead zirconate titanate) ceramics as a step-up transformer of a CFL lighting inverter used for an LCD panel of an A4 size notebook personal computer, a considerably large input voltage is required. And the step-up ratio was still insufficient.

Accordingly, it is an object of the present invention to provide a piezoelectric transformer having a high step-up ratio.

[0009]

According to the present invention, there is provided a piezoelectric substrate having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface and the piezoelectric substrate have a first main surface and a second main surface. A piezoelectric transformer using a longitudinal vibration resonance mode in a longitudinal direction of the piezoelectric substrate on which the second main surface extends, wherein the resonance mode includes:
A resonance mode in which a stress distribution of at least one wavelength or more (preferably one wavelength or more and an integral multiple of 波長 wavelength) exists in the longitudinal direction, and a half wavelength of the stress distribution at the time of the resonance in the longitudinal direction. The first main surface and the second main surface of the first region of the piezoelectric substrate in which any one of positive and negative stress occurs in the longitudinal direction at the time of the resonance. A primary electrode and a second primary electrode are provided to face each other, and a space between the first primary electrode and the second primary electrode in the first region is the first main surface and the second main electrode. A piezoelectric transformer provided with a secondary electrode in a second region of the piezoelectric substrate which is polarized in a thickness direction between the surfaces and is separated from the first region by a predetermined distance in the longitudinal direction; First
Between the region and the second region, in the longitudinal direction has a length of less than half a wavelength of the stress distribution at the time of the resonance, and at the time of the resonance any one of positive or negative in the longitudinal direction A third region where a stress is generated, wherein a third primary electrode and a fourth primary electrode are provided on the first main surface and the second main surface of the third region so as to face each other; , The first and second primary electrodes and the first
The third region vibrates according to the direction of the stress generated in the third region during the resonance so that the third region vibrates to further increase the resonance excited by the third region. Between the first primary electrode and the fourth primary electrode is polarized in a predetermined direction in the thickness direction, and the third primary electrode, the fourth primary electrode, the first primary electrode, and the second primary electrode. A primary electrode electrically connected in a predetermined connection state, and the piezoelectric ceramic substrate between the secondary electrode and an end of the third primary electrode and the fourth primary electrode on the secondary electrode side; Are polarized in the longitudinal direction, thereby providing a first piezoelectric transformer.

In the first piezoelectric transformer of the present invention,
First, the first region of the first region of the piezoelectric substrate, which has a half-wave length of the stress distribution at the time of resonance in the longitudinal direction of the piezoelectric substrate and at which one of positive and negative stresses occurs in the longitudinal direction at the time of resonance. A first primary electrode and a second primary electrode are provided on the main surface and the second main surface, respectively, so as to face each other, and a first main electrode and a second primary electrode in the first region are provided between the first primary electrode and the second primary electrode. A piezoelectric substrate provided with a secondary electrode in a second region of the piezoelectric substrate that is polarized in a thickness direction between the first surface and the second main surface and is separated from the first region by a predetermined distance in the longitudinal direction. A third region between the first region and the second region
And a first main surface and a second surface of the third region.
Since the third primary electrode and the fourth primary electrode are provided to face each other on the main surface, the electrode area on the primary side is larger, and the input impedance of the piezoelectric transformer is smaller. As a result, electric energy is easily supplied from the power supply to the piezoelectric transformer.

Further, in the first piezoelectric transformer of the present invention, the length in the longitudinal direction of the third region is equal to or less than a half wavelength of the stress distribution at the time of resonance. At the time of resonance, either positive or negative stress is generated in the longitudinal direction, and this third region is excited by the first and second primary electrodes of the first region and the first region. The third region is polarized in a predetermined direction in the thickness direction according to the direction of the stress generated in the third region at the time of resonance so that the third region vibrates to further increase the resonance. Since the third primary electrode and the fourth primary electrode are electrically connected to the first primary electrode and the second primary electrode in a predetermined connection state, resonance is further increased by the third region. , Input electric energy on the primary side Over it can be converted more efficiently to mechanical elastic energy.

On the other hand, by providing the third region, the third primary electrode and the fourth primary electrode provided in the third region are provided.
The piezoelectric ceramic substrate between the secondary electrode side end of the primary electrode and the secondary electrode is polarized in the longitudinal direction, and the secondary side is shortened in the longitudinal direction. As described above, when the distance between the primary electrode and the secondary electrode is reduced, the output impedance is 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.

As described above, by providing the third region as in the present invention, the input impedance of the piezoelectric transformer is reduced, so that electric energy is easily supplied from the power supply to the piezoelectric transformer. The electrical energy of the piezoelectric transformer can be more efficiently converted into mechanical elastic energy, the output impedance decreases, and the voltage that can be applied to the load connected to the secondary side of the piezoelectric transformer increases. The effective boost ratio can be increased.

Further, as described above, the third embodiment of the present invention
By providing the region between the first region and the second region, the distance between the primary electrode and the secondary electrode is reduced, so that the second primary electrode and the fourth primary electrode provided in the third region When the piezoelectric ceramic substrate between the end portion on the side of the next electrode and the secondary electrode is polarized in the longitudinal direction, the absolute voltage applied during polarization is smaller than when the third region is not provided. Become. As a result, it is easy to take measures against a high voltage, and a low-voltage power supply can be used.

The present invention works more effectively when the load connected to the secondary side of the piezoelectric transformer is a CFL. 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 starting discharge, CF
Since the impedance of L is close to infinity, the step-up ratio is proportional to Qm of the piezoelectric transformer itself, and the step-up ratio can be increased. Therefore, even if the distance between the primary electrode and the secondary electrode is shortened by providing the third region as in the present invention, and the step-up ratio determined by the shape of the secondary side becomes small,
As described above, at the start of discharge, Qm of the resonator itself greatly contributes to the boosting ratio, so that boosting to a voltage at which discharge can be started can be easily performed. When the discharge starts, C
Although the impedance of the FL decreases, the third
As described above, the output impedance of the piezoelectric transformer is reduced by providing the
Can be increased.

When the third region as in the present invention is provided between the first region on the primary side and the secondary electrode, the third region
By adjusting the size and the like of the third primary electrode and the fourth primary electrode provided in the region, not only the step-up ratio of the piezoelectric transformer but also the output impedance can be adjusted, and the degree of freedom in design is improved. I do.

In order to cause the third region to vibrate so as to further increase the resonance excited by the first region and the first and second primary electrodes, the third region must be set at the time of resonance. When the direction of the stress generated in the first region at the time of resonance is opposite to the direction of the stress generated in the first region, preferably, the polarization direction between the third primary electrode and the fourth primary electrode in the third region is The polarization direction is the same between the first primary electrode and the second primary electrode in the first region, and the third primary electrode and the second primary electrode are electrically connected to each other. The first primary electrode is electrically connected.

In order to cause the third region to vibrate so as to further increase the resonance excited by the first region and the first and second primary electrodes, the third region may be formed at the time of resonance. When the direction of the stress generated in the third region is opposite to the direction of the stress generated in the first region at the time of resonance, the polarization direction between the third primary electrode and the fourth primary electrode in the third region is
The direction of polarization between the first primary electrode and the second primary electrode in the first region is opposite to the direction of polarization, and the third primary electrode and the first primary electrode are electrically connected to each other. Second
It is also preferable to electrically connect the primary electrodes.

In order to cause the third region to vibrate so as to further increase the resonance excited by the first region and the first and second primary electrodes, the third region may be formed at the time of resonance. If the direction of the stress generated in the first region at the time of resonance is the same as the direction of the stress generated in the first region, the polarization direction between the third primary electrode and the fourth primary electrode in the third region is changed to the direction of the first region. The direction of polarization between the first primary electrode and the second primary electrode is the same, and the third primary electrode and the first primary electrode are electrically connected, and the fourth primary electrode and the second primary electrode are connected. Are preferably electrically connected.

Further, the length between the first region on the primary side of the piezoelectric substrate and the second region on the secondary side is equal to or less than half a wavelength of the stress distribution at the time of resonance in the longitudinal direction. A fourth region in which a stress only in the same direction as the stress generated in the first region at the time of resonance is provided, and a fifth primary electrode and a fifth primary electrode are provided on the first main surface and the second main surface of the fourth region. The sixth primary electrodes are provided to face each other, and the polarization direction between the fifth primary electrode and the sixth primary electrode in the fourth region is changed by changing the polarization direction between the first primary electrode in the first region and the second primary electrode. The fifth primary electrode and the first primary electrode are electrically connected, the sixth primary electrode and the second primary electrode are electrically connected, and the third primary electrode And the end of the fourth primary electrode on the secondary electrode side and the end of the fifth primary electrode and the sixth primary electrode on the secondary electrode side By polarized in the longitudinal direction of the piezoelectric ceramic substrate between the inner secondary electrodes by near either end portion and the secondary electrode, the first region first
And the resonance excited by the second primary electrode can be further increased.

The fifth aspect of the piezoelectric substrate has a half-wave length of the stress distribution at the time of resonance in the longitudinal direction, and generates either positive or negative stress in the longitudinal direction at the time of resonance.
Is further provided on the side opposite to the first region with respect to the second region so that the second region is sandwiched between the first region and the fifth region. A seventh primary electrode and an eighth primary electrode are provided on the first main surface and the second main surface of the region so as to face each other, and are excited by the first and second primary electrodes and the first region. The thickness between the seventh primary electrode and the eighth primary electrode in the fifth region is changed according to the direction of the stress generated in the fifth region at the time of resonance so that the fifth region vibrates to further increase the resonance. Polarization in a predetermined direction, electrically connecting the seventh primary electrode and the eighth primary electrode to the first primary electrode and the second primary electrode in a predetermined connection state, and Between the fifth region and the second region, a half-wavelength or less of the stress distribution at the time of resonance in the longitudinal direction. Sixth is one of the stress occurring within the positive or negative in the longitudinal direction at resonance has a length of
And a ninth primary electrode and a tenth primary electrode are provided on the first main surface and the second main surface of the sixth region, respectively, so as to face each other. The ninth primary of the sixth region depends on the direction of the stress generated in the sixth region at resonance, such that the sixth region vibrates to further increase the resonance excited by the electrode and the first region. The electrode between the ninth primary electrode and the tenth primary electrode is polarized in a predetermined direction in the thickness direction.
0 primary electrode and the first primary electrode and the second primary electrode are electrically connected to each other in a predetermined connection state, and the ends of the ninth and tenth electrodes on the secondary electrode side and the secondary electrode By polarizing the piezoelectric ceramic substrate between them in the longitudinal direction, energy can be injected into the piezoelectric transformer from both sides of the secondary electrode, and the step-up ratio of the piezoelectric transformer can be further increased.

In this piezoelectric transformer, the resonance mode is a resonance mode in which a stress distribution of at least 1.5 wavelength or more (preferably 1.5 wavelength or more and an integral multiple of 1/2 wavelength) exists in the longitudinal direction. It is preferably applied.

The second region, the third region and the sixth region
May coexist in the same half-wavelength region in the first or second principal surface direction of the stress distribution at the time of resonance and in which only compressive or tensile stress is generated.

Further, the first region and the fifth region are provided symmetrically with respect to the second region, and the third region and the sixth region are also provided with the second region.
Symmetrically with respect to the second region, twice as much energy can be injected as when the first region and the third region are provided only on one side of the second region.

In the fifth and sixth regions, the direction of the stress generated in the third region at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance. The polarization direction between the third primary electrode and the fourth primary electrode is
The polarization direction is the same as the polarization direction between the first primary electrode and the second primary electrode in the first region, the third primary electrode and the second primary electrode are electrically connected, and the fourth primary electrode and the fourth When the first primary electrode is electrically connected, a region in which the direction of the stress generated at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance is defined as a fifth region, and the fifth region The polarization direction between the seventh primary electrode and the eighth primary electrode is opposite to the polarization direction between the first primary electrode and the second primary electrode in the first region, and the seventh primary electrode and the first Are electrically connected, the eighth primary electrode and the second primary electrode are electrically connected, and the direction of stress generated at resonance is the same as the direction of stress generated in the first region at resonance. The region is a sixth region, and the polarization direction between the ninth primary electrode and the tenth primary electrode in the sixth region The direction of polarization between the first primary electrode and the second primary electrode in the first region is opposite, and the ninth primary electrode and the second primary electrode are electrically connected, and the tenth primary electrode and the It can be preferably formed by electrically connecting the first primary electrode.

In the fifth region and the sixth region, the direction of the stress generated in the third region at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance. The polarization direction between the third primary electrode and the fourth primary electrode is
The direction of polarization between the first primary electrode and the second primary electrode in the first region is the same, the third primary electrode and the second primary electrode are electrically connected, and the fourth primary electrode and the fourth primary electrode are electrically connected. When the first primary electrode is electrically connected, a region in which the direction of the stress generated at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance is defined as a fifth region, and the fifth region is defined as a fifth region. The polarization direction between the seventh primary electrode and the eighth primary electrode is the same as the polarization direction between the first primary electrode and the second primary electrode in the first region, and the seventh primary electrode and the second Are electrically connected, the eighth primary electrode and the first primary electrode are electrically connected, and the direction of the stress generated at the time of resonance is the same as the direction of the stress generated at the first region at the time of resonance. The region is a sixth region, and the polarization direction between the ninth primary electrode and the tenth primary electrode in the sixth region , The direction of polarization between the first primary electrode and the second primary electrode in the first region is the same, the ninth primary electrode and the first primary electrode are electrically connected, and the tenth primary electrode and the It is also preferably formed by electrically connecting the two primary electrodes.

Further, in the fifth region and the sixth region, the direction of the stress generated in the third region at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance. The polarization direction between the third primary electrode and the fourth primary electrode in the region is opposite to the polarization direction between the first primary electrode and the second primary electrode in the first region, and the third primary electrode and The first primary electrode is electrically connected, the fourth primary electrode and the second
When the primary electrodes are electrically connected to each other, a region in which the direction of the stress generated at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance is defined as a fifth region. The polarization direction between the seventh primary electrode and the eighth primary electrode is opposite to the polarization direction between the first primary electrode and the second primary electrode in the first region, and the seventh primary electrode and the first A region in which the primary electrode is electrically connected, the eighth primary electrode and the second primary electrode are electrically connected, and the direction of the stress generated at resonance is the same as the direction of the stress generated in the first region at resonance. Is the sixth region, and the polarization direction between the ninth primary electrode and the tenth primary electrode in the sixth region is the same as the polarization direction between the first primary electrode and the second primary electrode in the first region. The ninth primary electrode and the first primary electrode are electrically connected, and the tenth primary electrode and the first By electrically connecting the primary electrode, it is preferably formed.

In the fifth region and the sixth region, the direction of the stress generated in the third region at the time of resonance is opposite to the direction of the stress generated in the first region at the time of resonance. The polarization direction between the first primary electrode and the fourth primary electrode is opposite to the polarization direction between the first primary electrode and the second primary electrode in the first region, and the third primary electrode and the first primary electrode When the electrodes are electrically connected and the fourth primary electrode and the second primary electrode are electrically connected, the direction of the stress generated at the time of resonance is the same as the direction of the stress generated in the first region at the time of resonance. The opposite region is referred to as a fifth region, and the polarization direction between the seventh primary electrode and the eighth primary electrode in the fifth region is defined as the direction of polarization between the first primary electrode and the second primary electrode in the first region. And the seventh primary electrode and the second primary electrode are electrically connected,
The eighth primary electrode and the first primary electrode are electrically connected, and a region in which the direction of the stress generated at the time of resonance is the same as the direction of the stress generated in the first region at the time of resonance is defined as a sixth region,
The polarization direction between the ninth primary electrode and the tenth primary electrode in the sixth region is opposite to the polarization direction between the first primary electrode and the second primary electrode in the first region, and the ninth primary electrode Electrode and second
It is also preferably formed by electrically connecting the first primary electrode and the tenth primary electrode and the first primary electrode.

According to the present invention, the first main surface, the second main surface opposite to the first main surface, the first main surface and the second main surface extend. A piezoelectric substrate having a first end face and a second end face orthogonal to the longitudinal direction
In a piezoelectric transformer using the longitudinal vibration resonance mode in the longitudinal direction of the piezoelectric substrate, a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, and first and second primary electrodes are provided. Is on the first main surface and the second main surface of the piezoelectric substrate about 1 of a distance between the first end surface and the second end surface from the first end surface.
/ 2 extending in the longitudinal direction to a position at a distance of a length of / 2, and a first portion of a predetermined region of the piezoelectric substrate between the first and second primary electrodes and the secondary electrode. And third and fourth primary electrodes are provided on the main surface and the second main surface of the first and second primary electrodes, respectively, at a distance from the secondary electrode, between the first primary electrode and the second primary electrode. The piezoelectric substrate is polarized in a thickness direction between the first main surface and the second main surface, and the piezoelectric substrate between the third primary electrode and the fourth primary electrode is the piezoelectric substrate in the thickness direction. The first primary electrode and the second primary electrode are polarized in the same direction as the polarization direction of the piezoelectric substrate, and the fourth primary electrode and the first primary electrode are electrically connected to each other; A primary electrode and the second primary electrode are electrically connected; A second piezoelectric transformer, wherein the piezoelectric ceramic substrate between the secondary electrode and an end of the secondary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction. Is provided.

The second piezoelectric transformer is suitably applied to a piezoelectric transformer having a one-wavelength stress distribution in the longitudinal direction between the first end face and the secondary electrode, and can also increase the step-up ratio.

Further, according to the present invention, the first main surface, the second main surface facing the first main surface, the first main surface and the second main surface extend. A piezoelectric substrate having a first end face and a second end face orthogonal to the longitudinal direction
A piezoelectric transformer using the longitudinal vibration resonance mode in the longitudinal direction of the piezoelectric substrate, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, and a first and a second electrode are provided. A primary electrode is disposed on the first main surface and the second main surface of the piezoelectric substrate on the first main surface and the first main surface at a distance of about 1 from the first end surface to the second main surface.
And a third and a fourth primary electrode are provided on the first main surface and the second main surface of the piezoelectric substrate. , From the first end face to the first end face and the first end face from a position having a length of about 1/3 of the distance between the first end face and the second end face. The first end is moved to a position having a distance of about ／ of the distance between the first end face and the second end face.
And a second primary electrode and the secondary electrode are spaced apart from each other and provided to extend in the longitudinal direction, respectively.
The piezoelectric substrate between the first primary electrode and the second primary electrode is polarized in a thickness direction between the first main surface and the second main surface, and the third primary electrode and the fourth The piezoelectric substrate between the primary electrodes is in the first direction in the thickness direction.
The first primary electrode and the second primary electrode are polarized in the same direction as the polarization direction of the piezoelectric substrate, the fourth primary electrode and the first primary electrode are electrically connected, and the third primary electrode is electrically connected to the third primary electrode. An electrode and the second primary electrode are electrically connected, and the piezoelectric ceramic substrate is located between the secondary electrode and the end of the third primary electrode and the fourth primary electrode on the secondary electrode side. Are polarized in the longitudinal direction, thereby providing a third piezoelectric transformer.

This third piezoelectric transformer is suitably applied to a piezoelectric transformer in which a stress distribution of 1.5 wavelength exists in the longitudinal direction between the first end face and the secondary electrode, and can also increase the step-up ratio. .

In this case, on the first and second main surfaces of the predetermined region of the piezoelectric substrate between the third and fourth primary electrodes and the secondary electrode, the second substrate is spaced apart from the secondary electrode. Fifth and sixth
Are further provided, respectively, and the piezoelectric substrate between the fifth primary electrode and the sixth primary electrode is polarized in the thickness direction in the same direction as the polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode. Then, the fifth primary electrode and the first primary electrode are electrically connected, the sixth primary electrode and the second primary electrode are electrically connected, and the fifth primary electrode and the sixth primary electrode are electrically connected. By polarizing the piezoelectric ceramic substrate between the end on the secondary electrode side and the secondary electrode in the longitudinal direction, a piezoelectric transformer having a higher step-up ratio can be obtained.

Further, according to the present invention, the first main surface, the second main surface facing the first main surface, the first main surface and the second main surface extend. A piezoelectric substrate having a first end face and a second end face orthogonal to the longitudinal direction
A piezoelectric transformer using the longitudinal vibration resonance mode in the longitudinal direction of the piezoelectric substrate, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, and a first and a second electrode are provided. A primary electrode is disposed on the first main surface and the second main surface of the piezoelectric substrate on the first main surface and the first main surface at a distance of about 1 from the first end surface to the second main surface.
/ 2 extending in the longitudinal direction to a position at a distance of a length of / 2, wherein the first portion of the predetermined region of the piezoelectric substrate between the first and second primary electrodes and the secondary electrode is provided. A third and a fourth primary electrode are respectively provided on the main surface and the second main surface of the first and second main electrodes so as to be separated from the secondary electrode, and between the first and second primary electrodes. The piezoelectric substrate is polarized in a thickness direction between the first main surface and the second main surface, and the piezoelectric substrate between the third primary electrode and the fourth primary electrode is the piezoelectric substrate in the thickness direction. The third primary electrode and the first primary electrode are polarized in a direction opposite to a polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode, and the fourth primary electrode is electrically connected to the fourth primary electrode. A primary electrode and the second primary electrode are electrically connected; A fourth piezoelectric transformer, wherein the piezoelectric ceramics substrate between the secondary electrode and an end of the secondary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction. Is provided.

This fourth piezoelectric transformer is suitably applied to a piezoelectric transformer in which a stress distribution of one wavelength exists in the longitudinal direction between the first end face and the secondary electrode, and can increase the step-up ratio.

According to the invention, the first main surface, the second main surface facing the first main surface, the first main surface and the second main surface extend. A piezoelectric substrate having a first end face and a second end face orthogonal to the longitudinal direction
A piezoelectric transformer using the longitudinal vibration resonance mode in the longitudinal direction of the piezoelectric substrate, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, and a first and a second electrode are provided. A primary electrode is disposed on the first main surface and the second main surface of the piezoelectric substrate on the first main surface and the first main surface at a distance of about 1 from the first end surface to the second main surface.
And a third and a fourth primary electrode are provided on the first main surface and the second main surface of the piezoelectric substrate. The distance from the first end face to the first end face and the second end face being a distance of about 1/3 of the distance between the first end face and the first end face; The first primary electrode is provided so as to extend in the longitudinal direction, apart from the secondary electrode, to a position having a length of about ／ of a distance from the second end face. And the piezoelectric substrate between the second primary electrode is polarized in a thickness direction between the first main surface and the second main surface, and the piezoelectric substrate between the third primary electrode and the fourth primary electrode. The direction of polarization of the piezoelectric substrate between the first primary electrode and the second primary electrode in the thickness direction of the piezoelectric substrate. Polarized in opposite directions, the third primary electrode and the first primary electrode are electrically connected, the fourth primary electrode and the second primary electrode are electrically connected, A fifth piezoelectric transformer, wherein the piezoelectric ceramic substrate between the secondary electrode and an end of the primary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction. Is provided.

This fifth piezoelectric transformer is suitably applied to a piezoelectric transformer in which a stress distribution of 1.5 wavelength exists in the longitudinal direction between the first end face and the secondary electrode, and can also increase the step-up ratio. .

In this case, on the first main surface and the second main surface of the predetermined region of the piezoelectric substrate between the third and fourth primary electrodes and the secondary electrode, the second substrate is spaced apart from the secondary electrode. Fifth and sixth
Are further provided, respectively, and the piezoelectric substrate between the fifth primary electrode and the sixth primary electrode is polarized in the thickness direction in the same direction as the polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode. Then, the fifth primary electrode and the first primary electrode are electrically connected, the sixth primary electrode and the second primary electrode are electrically connected, and the fifth primary electrode and the sixth primary electrode are electrically connected. By polarizing the piezoelectric ceramic substrate between the end on the secondary electrode side and the secondary electrode in the longitudinal direction, a piezoelectric transformer having a higher step-up ratio can be obtained.

According to the invention, there is provided a piezoelectric substrate having a first main surface and a second main surface facing the first main surface, wherein the first main surface and the second main surface are provided. One direction in which the main surface extends is defined as a longitudinal direction of the piezoelectric substrate, and the piezoelectric substrate has at least a first region, a second region, and a third region that divide the longitudinal direction. Has a length of about 1 / n (n is an integer of 2 or more) of the length of the piezoelectric substrate in the longitudinal direction, and the first region of the first region has a length of 1 / n. First and second main surfaces
A first primary electrode and a second primary electrode are provided so as to face each other, and a space between the first primary electrode and the second primary electrode in the first region is the first main surface and the second primary electrode. A secondary electrode is provided in the second region of the piezoelectric substrate that is polarized in the thickness direction between the main surfaces and is separated from the first region by a predetermined distance in the longitudinal direction, and the third region is provided in the third region. The first main portion of the third region is provided between the first region and the second region, has a length equal to or less than 1 / n of the length of the piezoelectric substrate in the longitudinal direction. A third primary electrode and a fourth primary electrode are provided on a surface and the second main surface, respectively, so as to face each other, and a gap between the third primary electrode and the fourth primary electrode in the third region is provided. The third primary electrode and the fourth electrode are polarized in a predetermined direction of the thickness direction. A sixth piezoelectric transformer is provided in which a primary electrode, the first primary electrode, and the second primary electrode are electrically connected in a predetermined connection state, and the second region is polarized in the longitudinal direction. Is done.

The resonance mode is determined by the input frequency of the primary electrode, the physical properties of the piezoelectric substrate, and the length in the vibration direction. Here, 1 / n length in the longitudinal direction of the piezoelectric substrate corresponds to a half wavelength of the resonance mode. Therefore, for example, n is 3 when the resonance mode is 1.5 wavelengths, and 2 when the resonance mode is 1 wavelength. Since the resonance mode in the piezoelectric transformer can take any large wave number, n can be an integer of 2 or more.

In the sixth piezoelectric transformer of the present invention,
The first primary surface and the second main surface of the first region having a length of about 1 / n (n is an integer of 2 or more) of the length in the longitudinal direction of the piezoelectric substrate have a first primary surface. An electrode and a second primary electrode are provided to face each other, and a polarization between the first primary electrode and the second primary electrode in the first region in a thickness direction between the first main surface and the second main surface is provided. In the piezoelectric transformer in which the secondary electrode is provided in the second region of the piezoelectric substrate which is separated from the first region by a predetermined distance in the longitudinal direction, the first region and the second region of the piezoelectric substrate Has a third region, and a third primary electrode and a fourth primary electrode are respectively provided on the first main surface and the second main surface of the third region so as to face each other. The electrode area on the side is larger, and the input impedance of the piezoelectric transformer is smaller. As a result, electric energy is easily supplied from the power supply to the piezoelectric transformer.

Further, in the piezoelectric transformer according to the sixth aspect of the present invention, the first region has a length substantially equal to the length of the piezoelectric substrate in the longitudinal direction.
/ N (n is an integer of 2 or more), so that the first region has a half-wave length of the stress distribution at the time of resonance in the longitudinal direction of the piezoelectric substrate. The region of the piezoelectric substrate in which one of positive and negative stresses occurs in the longitudinal direction at the time of resonance. Also, since the third region has a length of 1 / n or less of the length in the longitudinal direction of the piezoelectric substrate, the third region
The region has a length equal to or less than a half wavelength of the stress distribution at the time of resonance in the longitudinal direction of the piezoelectric substrate, and is a region where one of positive and negative stresses is generated in the longitudinal direction at the time of resonance. Then, the first main surface of the third region and the second main surface
A third primary electrode and a fourth primary electrode are provided on the main surface of the third region so as to face each other, and the third primary electrode and the fourth primary electrode in the third region are polarized in a predetermined direction in the thickness direction. And the third primary electrode and the fourth primary electrode and the first primary electrode and the second primary electrode are electrically connected to each other in a predetermined connection state. Depending on the direction of the resulting stress, the first and second
This third region can be made to oscillate to further increase the resonance excited by the primary electrode as well as the first region, so that the third region further increases the resonance and on the primary side The input electric energy can be more efficiently converted into mechanical elastic energy.

On the other hand, by providing the third region, the third primary electrode and the fourth primary electrode provided in the third region are provided.
The piezoelectric ceramic substrate between the secondary electrode side end of the primary electrode and the secondary electrode can be polarized in the longitudinal direction, and the first region of the first region can be polarized without providing the third region. The secondary side is shorter in the longitudinal direction than when the piezoelectric ceramic substrate between the secondary electrode side end of the primary electrode and the second primary electrode and the secondary electrode is polarized in the longitudinal direction. As described above, when the distance between the primary electrode and the secondary electrode is reduced, the output impedance is 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.

As described above, by providing the third region as in the present invention, the input impedance of the piezoelectric transformer is reduced, so that electric energy is easily supplied from the power supply to the piezoelectric transformer. Can be more efficiently converted into mechanical elastic energy, the output impedance can be reduced, and the voltage that can be applied to the load connected to the secondary side of the piezoelectric transformer increases, The effective step-up ratio of the piezoelectric transformer can be increased.

Further, as described above, the third embodiment of the present invention
By providing the region between the first region and the second region, the distance between the primary electrode and the secondary electrode is reduced, so that the second primary electrode and the fourth primary electrode provided in the third region When the piezoelectric ceramic substrate between the end portion on the side of the next electrode and the secondary electrode is polarized in the longitudinal direction, the absolute voltage applied during polarization is smaller than when the third region is not provided. Become. As a result, it is easy to take measures against a high voltage, and a low-voltage power supply can be used.

When the third region as in the present invention is provided between the first region on the primary side and the secondary electrode, the third region
By adjusting the size and the like of the third primary electrode and the fourth primary electrode provided in the region, not only the step-up ratio of the piezoelectric transformer but also the output impedance can be adjusted, and the degree of freedom in design is improved. I do.

In order to make the third region vibrate so as to further increase the resonance excited by the first region and the first and second primary electrodes, the third region must be formed at the time of resonance. When the direction of the stress generated in the first region at the time of resonance is opposite to the direction of the stress generated in the first region, preferably, the polarization direction between the third primary electrode and the fourth primary electrode in the third region is The polarization direction is the same between the first primary electrode and the second primary electrode in the first region, and the third primary electrode and the second primary electrode are electrically connected to each other. The first primary electrode is electrically connected.

In order to cause the third region to vibrate so as to further increase the resonance excited by the first region and the first and second primary electrodes, the third region should When the direction of the stress generated in the third region is opposite to the direction of the stress generated in the first region at the time of resonance, the polarization direction between the third primary electrode and the fourth primary electrode in the third region is
The direction of polarization between the first primary electrode and the second primary electrode in the first region is opposite to the direction of polarization, and the third primary electrode and the first primary electrode are electrically connected to each other. Second
It is also preferable to electrically connect the primary electrodes.

To make the third region vibrate so as to further increase the resonance excited by the first region and its first and second primary electrodes, the third region
Distance between the first region and the first region is 1 of the longitudinal length.
/ N or more and when the direction of the stress generated in the third region at the time of resonance is the same as the direction of the stress generated in the first region at the time of resonance, the third primary electrode of the third region and the fourth primary electrode The direction of polarization between the electrodes is the same as the direction of polarization between the first primary electrode and the second primary electrode in the first region, and the third primary electrode and the first primary electrode are electrically connected. Preferably, the fourth and fourth primary electrodes are electrically connected.

Further, the length between the first region on the primary side of the piezoelectric substrate and the second region on the secondary side is not more than 1 / n of the length in the longitudinal direction of the piezoelectric substrate. Has a length equal to or less than half a wavelength of the stress distribution at the time of resonance, and
A fourth region in which a stress only in the same direction as the direction of the stress generated in the region at the time of resonance is provided, and the first primary surface and the second primary surface of the fourth region have a fifth primary electrode and a fourth 6 primary electrodes are provided to face each other, and the polarization direction between the fifth primary electrode and the sixth primary electrode in the fourth region is
The direction of polarization between the first primary electrode and the second primary electrode in the first region is the same, the fifth primary electrode and the first primary electrode are electrically connected, and the sixth primary electrode and the second primary electrode are electrically connected. By electrically connecting the primary electrodes, the resonance excited by the first and second primary electrodes in the first region can be further increased. It should be noted that any one of the ends of the third primary electrode and the fourth primary electrode on the secondary electrode side and the end of the fifth primary electrode and the sixth primary electrode on the secondary electrode side which is closer to the secondary electrode. Preferably, the piezoelectric ceramic substrate between one end and the secondary electrode is polarized in the longitudinal direction.

Further, the fifth division of the piezoelectric substrate in the longitudinal direction is performed.
And a sixth area are further provided, and a fifth area is provided on the opposite side of the first area with respect to the second area, and a length of the fifth area is equal to a length of the piezoelectric substrate in the longitudinal direction. The length is approximately 1 / n, and a seventh primary electrode and an eighth primary electrode are provided on the first main surface and the second main surface of the fifth region so as to face each other. Polarize the gap between the seventh primary electrode and the eighth primary electrode in a predetermined direction in the thickness direction, and connect the seventh primary electrode, the eighth primary electrode, the first primary electrode, and the second primary electrode to a predetermined direction. A sixth region is provided between the fifth region and the second region, and the length of the sixth region is 1 / n of the length of the piezoelectric substrate in the longitudinal direction. The ninth primary electrode and the tenth primary electrode are respectively attached to the first main surface and the second main surface of the sixth region. The first and second ninth and tenth primary electrodes are polarized in a predetermined direction in the thickness direction between the ninth and tenth primary electrodes in the sixth region. And the second primary electrode are electrically connected in a predetermined connection state, the secondary electrode is provided on at least one of the first and second main surfaces, and the second regions on both sides of the secondary electrode are elongated. By polarizing in the direction,
The fifth region has a length of a half wavelength of the stress distribution at the time of resonance in the longitudinal direction of the piezoelectric substrate, and is a region in which any one of positive and negative stress is generated in the longitudinal direction at the time of resonance. Depending on the direction of the stress generated in the area,
The fifth region may be oscillated to further increase the resonance excited by the first and second primary electrodes and the first region, and the sixth region may extend longitudinally of the piezoelectric substrate. A region having a length equal to or less than a half wavelength of the stress distribution at the time of resonance and in which one of positive or negative stress occurs in the longitudinal direction at the time of resonance, and depending on the direction of the stress generated in the sixth region at the time of resonance This sixth region can be made to vibrate to further increase the resonance excited by the first and second primary electrodes and the first region, so that energy can be transferred from both sides of the secondary electrode to the piezoelectric region. It can be injected into a transformer, and the step-up ratio of the piezoelectric transformer can be further increased.

This piezoelectric transformer has a resonance mode in which the longitudinal mode has a stress distribution of at least 1.5 wavelengths or more (preferably 1.5 wavelengths or more and an integral multiple of 1/2 wavelength). It is preferably applied.

The second region, the third region and the sixth region
May coexist in the same half-wavelength region in the first or second principal surface direction of the stress distribution at the time of resonance and in which only compressive or tensile stress is generated. For this purpose, the length in the longitudinal direction of the region including the second region, the third region, and the sixth region is set to one of the longitudinal length of the piezoelectric substrate.
/ N or less.

The first region and the fifth region are provided symmetrically with respect to the second region, and the third region and the sixth region are also provided with the second region.
Symmetrically with respect to the second region, twice as much energy can be injected as when the first region and the third region are provided only on one side of the second region.

Further, in the sixth piezoelectric transformer,
The piezoelectric substrate has a first end face and a second end face orthogonal to the longitudinal direction, and the first and second primary electrodes are separated from the first end face by a distance between the first end face and the second end face. The third and fourth primary electrodes are provided to be spaced apart from the secondary electrode, respectively, so as to extend to a position at a distance of about の of the length of the third region. Polarized in the thickness direction in the same direction as the polarization direction of the first region,
A primary electrode and a first primary electrode are electrically connected;
The piezoelectric transformer, in which the third primary electrode and the second primary electrode are electrically connected, has a first end face and a second end face.
The present invention is suitably applied to a piezoelectric transformer in which a stress distribution of one wavelength exists in the longitudinal direction between the end faces of the piezoelectric transformer, and can also increase the step-up ratio.

Also, in the sixth piezoelectric transformer,
The piezoelectric substrate has a first end face orthogonal to the longitudinal direction and a second end face.
And the first and second primary electrodes are arranged such that the first and second primary electrodes are separated from the first end face by about 1 / th of the distance between the first and second end faces.
A third distance between the first end face and the second end face from the first end face. About 1 /
3 from the position of the distance of the length from the first end face to a position of a distance of about ／ or less of the distance between the first end face and the second end face. And the third region is polarized in the same direction as the polarization direction of the first region in the thickness direction, and the fourth primary electrode and the first primary electrode are electrically extended. The piezoelectric transformer, which is connected so that the third primary electrode and the second primary electrode are electrically connected, has 1.5 wavelengths in the longitudinal direction between the first end face and the second end face. It is suitably applied to a piezoelectric transformer having a stress distribution, and can also increase the step-up ratio.

In this case, the third and fourth primary electrodes are provided on the first and second main surfaces of the predetermined region of the piezoelectric substrate between the third and fourth primary electrodes and the secondary electrodes. And a fifth and a sixth primary electrode are further provided separately from the secondary electrode. Polarized in the same direction as the polarization direction of the piezoelectric substrate between the primary electrodes,
By electrically connecting the primary electrode and the first primary electrode and electrically connecting the sixth primary electrode and the second primary electrode, a piezoelectric transformer having a higher step-up ratio can be obtained. Preferably, the piezoelectric ceramic substrate between the secondary electrode and the end of the fifth primary electrode and the sixth primary electrode on the secondary electrode side is polarized in the longitudinal direction.

Also, in the sixth piezoelectric transformer,
The piezoelectric substrate has a first end face orthogonal to the longitudinal direction and a second end face.
And the first and second primary electrodes are approximately one-half of the distance between the first and second end faces from the first end face.
, And the third and fourth primary electrodes are provided separately from the secondary electrodes, respectively, and the third region is provided in the first direction in the thickness direction. Is polarized in the direction opposite to the polarization direction of the region, the third primary electrode and the first primary electrode are electrically connected, and the fourth primary electrode and the second primary electrode are electrically connected. The piezoelectric transformer described above is suitably applied to a piezoelectric transformer having a stress distribution of one wavelength in the longitudinal direction between the first end face and the second end face, and can increase the step-up ratio.

In the sixth piezoelectric transformer,
The piezoelectric substrate has a first end face orthogonal to the longitudinal direction and a second end face.
And the first and second primary electrodes are approximately one-third of the distance from the first end surface to the first and second end surfaces.
And a third and a fourth primary electrode are provided extending in the longitudinal direction to a position of a distance of the length from the first end face to a distance between the first end face and the second end face. 1/3
From the position at a distance of the length from the first end surface to a position at a distance of about ／ or less of the distance between the first end surface and the second end surface. , The third region is polarized in a direction opposite to the polarization direction of the first region in the thickness direction, and the third primary electrode and the first primary electrode are electrically connected to each other. And the fourth
In the piezoelectric transformer in which the primary electrode and the second primary electrode are electrically connected, a stress distribution of 1.5 wavelength exists in the longitudinal direction between the first end face and the second end face. It is suitably applied to a piezoelectric transformer, and can also increase the step-up ratio.

In this case, the third and fourth primary electrodes are provided on the first and second principal surfaces of the predetermined region of the piezoelectric substrate between the third and fourth primary electrodes and the secondary electrodes. A fifth primary electrode and a sixth primary electrode are further provided separately from the secondary electrode, and the piezoelectric substrate between the fifth primary electrode and the sixth primary electrode is disposed in the thickness direction with the first primary electrode and the second primary electrode. Polarized in the same direction as the polarization direction of the piezoelectric substrate between the primary electrodes,
By electrically connecting the primary electrode and the first primary electrode and electrically connecting the sixth primary electrode and the second primary electrode, a piezoelectric transformer having a higher step-up ratio can be obtained. Preferably, the piezoelectric ceramic substrate between the secondary electrode and the end of the fifth primary electrode and the sixth primary electrode on the secondary electrode side is polarized in the longitudinal direction.

The secondary electrode is preferably formed on the longitudinal end face of the piezoelectric substrate. This is because an ideal vibration mode is easily realized.

The secondary electrode may be formed on at least one of the first main surface and the second main surface of the piezoelectric substrate. In this case, a secondary electrode can be formed simultaneously with the primary electrode in one film forming step. Further, by adjusting the area of the secondary electrode, the distance from the primary electrode can be adjusted, and as a result, the output impedance of the piezoelectric transformer can be adjusted. On the other hand, the resonance frequency of the piezoelectric transformer is determined by the length in the longitudinal direction of the piezoelectric substrate. Therefore, by forming the secondary electrode on at least one of the first main surface and the second main surface of the piezoelectric substrate, the resonance frequency and the output impedance can be controlled independently. . In addition, when the secondary electrode is formed on both the first main surface and the second main surface of the piezoelectric substrate, the polarization in the longitudinal direction becomes easier.

Further, the above-described piezoelectric transformers are laminated and integrated in a plurality of thickness directions, the primary region of each piezoelectric transformer is laminated with the primary region of another piezoelectric transformer, and the secondary region of each piezoelectric transformer is laminated with the other region. It is also preferable that the secondary regions of the piezoelectric transformers are laminated, and the polarization direction of the primary regions of the plurality of piezoelectric transformers and the connection state of the primary electrodes are set so that the plurality of piezoelectric transformers further increase mutual vibration. . In this case, it is more preferable that the laminated piezoelectric transformers have the same structure and the corresponding electrodes are electrically connected in parallel.

In this way, since the input current flows by the number of layers, the input voltage becomes 1 / the number of layers when the input power is constant, and the input voltage can be reduced. In addition, since the input current can be made to flow by the number of layers, the input power can be increased to perform high-power driving. On the other hand, when a single-plate piezoelectric transformer is used, if the energy density increases due to an increase in power, the loss increases above a threshold determined by the material, causing a decrease in efficiency. In order to avoid this, the energy density in the piezoelectric ceramic is reduced by adopting the above-mentioned laminated structure,
The total input power level can be increased. In addition, by integrating a plurality of piezoelectric transformers as described above, the vibration mode of the plurality of piezoelectric transformers can be made a single vibration mode.

By providing the supporting portion of the piezoelectric transformer at the position of the node of the vibration in the resonance mode of each piezoelectric transformer, it is possible to prevent the vibration of the piezoelectric transformer from being hindered and to prevent the conversion efficiency from being lowered.

Further, by using a part of the primary electrode as a feedback electrode provided electrically insulated from the primary electrode, the vibration state of the piezoelectric transformer can be reduced in the form of a small signal using the feedback electrode. A signal to be monitored can be taken out, the feedback can be applied to the piezoelectric transformer by using the signal, and the piezoelectric transformer can be self-oscillated.

The self-excited oscillation can be preferably generated by connecting a phase shift circuit and an amplifier circuit to the feedback electrode and applying the output of the amplifier circuit to the primary electrode.

The piezoelectric transformer of the present invention is preferably used as a cold cathode tube lighting piezoelectric transformer.

The piezoelectric transformer of the present invention is preferably incorporated in an inverter.

Further, the piezoelectric transformer of the present invention is suitably incorporated in a liquid crystal display.

Further, the piezoelectric transformer of the present invention
It is also suitably used for a high voltage deflection circuit of a cathode ray tube, and a high voltage generating circuit such as a copying machine and a facsimile.

The piezoelectric material used as the piezoelectric substrate in the present invention is, for example, PZT or
PbTiO ₃ -based piezoelectric ceramics such as PbTiO ₃ are used. Examples of PZT ceramics include PZT, Pb (Ni _1/3 Nb _2/3 ) O ₃ -Pb (Z
n _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ -PbZrO ₃ ceramics.

The electrode material used in the present invention includes Ag and Ag-Pd.

[0074]

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

(First Embodiment) FIG. 1 is a diagram for explaining a piezoelectric transformer according to a first embodiment.
1B is a perspective view, FIG. 1B is a sectional view, FIG. 1C is a view showing a stress distribution, and FIG. 1D is a view showing an amplitude distribution. FIG. 2 is a diagram showing the relationship between the input voltage to the piezoelectric transformer of the present embodiment and the luminance of the cold cathode tube.

As shown in FIGS. 1A and 1B, a primary electrode 22 is provided on the left (primary) half of the upper surface 12 of the piezoelectric ceramic substrate 10 having a rectangular parallelepiped shape. Primary electrode 24 also on lower surface 14
Is provided, and the piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24 is polarized in the thickness direction between the upper surface 12 and the lower surface 14.

The upper surface 12 of the piezoelectric ceramic substrate 10 is spaced from the primary end face 16 by half the longitudinal length of the piezoelectric ceramic substrate 10, from the primary end face 16 to the longitudinal direction of the piezoelectric ceramic substrate 10. A primary electrode 26 is provided up to a position separated by a distance of ／ of the length.
The primary electrode 28 is also provided on the lower surface 14 of the zero. The primary electrode 26 is provided separately from the primary electrode 22, and the primary electrode 28 is provided separately from the primary electrode 24. Piezoelectric ceramic substrate 1 between primary electrode 26 and primary electrode 28
0 is polarized in the thickness direction between the upper surface 12 and the lower surface 14. The polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24 and the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 26 and the primary electrode 28 are the same.

A secondary electrode 72 is provided on the secondary end face 18 perpendicular to the upper surface 12 and the lower surface 14, and the primary electrodes 26, 2
The piezoelectric ceramic substrate 10 between the secondary electrode 8 and the secondary electrode 72 is polarized in the longitudinal direction in which the upper surface 12 and the lower surface 14 extend.

One end of the power supply 82 is connected to the primary electrode 22 via the connection 122 and to the primary electrode 28 via the connection 128. The other end of the power supply 82 is connected to
Is connected to the primary electrode 24 via the connection part 126 and to the primary electrode 26 via the connection part 126. The secondary electrode 72 is connected to one end of the CFL 90 as a load, and the other end of the CFL 90 is connected to the other end of the power supply 82.

When a voltage is applied between the primary electrodes 22 and 24 from the power supply 82, an electric field is applied in the thickness direction in the left half, and the longitudinal vibration in the longitudinal direction is caused by the piezoelectric transverse effect displaced in the direction perpendicular to the polarization direction. When excited, the entire piezoelectric transformer 100 vibrates. In the piezoelectric transformer according to the present embodiment, driving is performed in a resonance mode in which a stress distribution of one wavelength exists between the primary end face 16 and the secondary end face 18. From the power supply 82, a voltage having a frequency equal to the frequency of the resonance in the one-wavelength mode is applied. In the present embodiment, the primary side end face 16
A support point is provided at a location that is 右側 wavelength away from the right side and a location that is １ ／ wavelength left from the secondary end face 18. Since both the primary end face 16 and the secondary end face 18 of the piezoelectric ceramic substrate 10 are open, the stress is zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 10, and the amplitude is maximized. In the present embodiment, since resonance is performed in the one-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 1C and 1D, respectively.

In the present embodiment, the primary electrode 22,
In addition to 24, primary electrodes 26 and 28 are further provided. Therefore, the electrode area on the primary side a is larger than that of the conventional piezoelectric transformer shown in FIG.
00 has a small input impedance. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82.

The stress in the region where the primary electrodes 22 and 24 are provided is in the direction of the upper surface 12 of the piezoelectric ceramic substrate 10, whereas the stress in the region where the primary electrodes 26 and 28 are provided is This is the direction of the lower surface of the ceramic substrate 10 and opposite to the stress in the region where the primary electrodes 22 and 24 are provided. Primary electrode 26 and primary electrode 2
8 is the same as the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24, but the direction of application of the electric field is opposite. Therefore, the primary electrodes 26, 2
When a voltage is applied between the primary electrodes 26 and 28, the piezoelectric ceramic substrate 10 between the primary electrodes 26 and 28
It vibrates to further increase the resonance excited by the voltage applied between 2 and 24. As a result, the electrical energy supplied from the power supply 82 on the primary side a can be more efficiently converted into mechanical elastic energy.

On the other hand, by providing the primary electrodes 26 and 28, the region on the secondary side b becomes shorter in the longitudinal direction,
As a result, the output impedance decreases. As described above, when the output impedance of the piezoelectric transformer 100 decreases, the voltage applied to the CFL 90 connected to the secondary electrode 72 of the piezoelectric transformer 100 increases accordingly.

As described above, the primary electrodes 26 and 28 are provided in the region where the stress in the direction opposite to the stress in the region where the primary electrodes 22 and 24 are provided, and the primary electrode 26 and the primary electrode 2 are provided.
8, the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24 is the same as the polarization direction of the piezoelectric ceramic substrate 10, and the direction of application of the electric field is reversed. Of the power supply 82
From the piezoelectric transformer 100, the input electric energy can be more efficiently converted into mechanical elastic energy on the primary side a, and the output impedance is further reduced. Since the voltage that can be applied to the CFL 90 connected to b increases, the effective boosting ratio of the piezoelectric transformer 100 can be increased.

Further, since the distance between the primary electrode and the secondary electrode is shortened by providing the primary electrodes 26 and 28 as in the present embodiment, the distance between the primary electrodes 26 and 28 and the secondary electrode 72 is reduced. When the piezoelectric ceramic substrate 10 is polarized in the longitudinal direction, the primary electrodes 26, 2
The absolute voltage applied during polarization is smaller than that of the conventional piezoelectric transformer shown in FIG. As a result, it is easy to take measures against a high voltage, and a low-voltage power supply can be used.

The present invention works more effectively even when the load connected to the secondary side b of the piezoelectric transformer is the CFL 90 as in the present embodiment. CFL90
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 100 is proportional to Qm which is a quality factor of the resonator. Before starting discharge, CFL90
Of the piezoelectric transformer 1
Since the boosting ratio is proportional to Qm of 00 itself, the boosting ratio can be increased. Therefore, even though the distance between the primary electrode and the secondary electrode is shortened by providing the primary electrodes 26 and 28 as in the present embodiment and the step-up ratio determined by the shape of the secondary side is reduced, as described above, At the start of discharge, Qm of the resonator itself greatly contributes to the boost ratio, so that boosting to a voltage at which discharge can be started can be easily performed. When the discharge starts, the impedance of the CFL 90 decreases, but the output impedance of the piezoelectric transformer 100 decreases by providing the primary electrodes 26 and 28 as in the present embodiment, so that the voltage applied to the CFL 90 increases accordingly. can do.

The primary electrode 2 according to the present embodiment is used.
By providing the primary electrodes 6 and 28, not only the boost ratio of the piezoelectric transformer 100 but also the output impedance can be adjusted by adjusting the size and the like of the primary electrodes 26 and 28, and the degree of freedom in design is improved.

In this embodiment, since the vibration nodes 202 and 204 are used as the supporting points of the piezoelectric transformer 100, the inhibition of the vibration of the piezoelectric transformer 100 caused by supporting the piezoelectric transformer 100 is extremely reduced. be able to. Further, in the present embodiment, the connection portions 122 and 124 of the primary electrodes 22 and 24 and the electrode terminals provided at these connection portions 122 and 124 are also connected to the nodes 202 of the vibration.
And the connection portions 126 and 128 of the primary electrodes 26 and 28 and the electrode terminals provided at the connection portions 126 and 128 are also provided at the vibration node 204, so that the vibration can be prevented from being hindered by the electrical connection portion. .

In this embodiment, Pb (Ni _1/3
Nb _2/3 ) O ₃ -Pb (Zn _1/3 Nb _2/3 ) O ₃ -Pb
A rectangular parallelepiped having a length of 20 mm, a width of 5 mm, and a thickness of 1 mm was cut out from the TiO ₃ -PbZrO ₃ -based piezoelectric ceramic fired body to obtain a piezoelectric ceramic substrate 10. Next, a silver electrode was applied to the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10 by screen printing, and was also applied to the secondary side end surface 18 by brush painting. Thereafter, baking is performed at 600 ° C. in the air, and a primary electrode 22 is formed on the upper surface 12 of the piezoelectric ceramic substrate 10.
26, primary electrodes 24 and 28 are formed on the lower surface 14 of the piezoelectric ceramic substrate 10, and a secondary electrode 72 is formed on the secondary end face 18 of the piezoelectric ceramic substrate 10, respectively.

Thereafter, 10 kV DC is applied between the primary electrode 22 and the primary electrode 24 and between the primary electrode 26 and the primary electrode 28.
The primary electrode 22 and the primary electrode 2 are applied in an environment of 0 ° C.
4 and the polarization process in the thickness direction of the piezoelectric ceramic substrate 10 between the primary electrode 26 and the primary electrode 28 was performed. Then, the primary electrode 26 and the primary electrode 28 are connected to the positive electrode of the DC high-voltage power supply, and the secondary electrode 72 is connected to the negative electrode of the DC high-voltage power supply. A polarization process was performed on the piezoelectric ceramic substrate 10 with the secondary electrode 72 in the longitudinal direction.

Thereafter, one end of the power supply 82 is connected to the primary electrode 22 via the connection section 122, the primary electrode 28 is connected via the connection section 128, and the other end of the power supply 82 is connected via the connection section 124 to the primary electrode. 24, and connected to the primary electrode 26 via the connection portion 126. The secondary electrode 72 was connected to one end of the CFL 90, and the other end of the CFL 90 was connected to the other end of the power supply 82. As the CFL 90, a CFL 90 having a length of 225 mm and a diameter of 2.6 mm used in an A4 notebook personal computer was used.

In the vibration nodes 202 and 204, the piezoelectric transformer 100 is
Hz, a relationship between the input voltage to the piezoelectric transformer 100 and the luminance of the CFL was measured. Figure 2 shows the result.
(See curve P). In FIG. 2, the piezoelectric transformer 100 shown in FIG. (See curve Q) is also shown for comparison.
In a piezoelectric transformer without the primary electrodes 26 and 28, CF
In order to obtain 27,000 cd / m ² luminance in L90, 6
Although an input voltage of 6 V _rms was required, in the present embodiment, the same luminance was obtained with an input voltage of 30 V _rms .

Note that the lighting of the CFL 90 is approximately 15 V _rms.
Could be started by applying an input voltage of

(Second to Fifth Embodiments) FIG. 3 is a diagram for explaining a piezoelectric transformer of the second to fourth embodiments, and FIG. 3A is a diagram illustrating a piezoelectric transformer of the second embodiment. FIG. 3B is a sectional view of a piezoelectric transformer according to a third embodiment, FIG. 3C is a sectional view of a piezoelectric transformer according to a fourth embodiment, and FIG. 3D is a sectional view of FIGS. 3C is a diagram showing a stress distribution of the piezoelectric transformer shown in FIG. 3C, and FIG. 3E is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIGS. 3A to 3C.

FIG. 4 is a view for explaining the piezoelectric transformer of the fifth embodiment. FIG. 4A is a sectional view of the piezoelectric transformer of the fifth embodiment, and FIG. 4B is shown in FIG. 4A. FIG. 4C is a diagram showing a stress distribution of the piezoelectric transformer, and FIG.
FIG. 3 is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIG.

As shown in FIG. 3A, in the second embodiment, the primary electrodes 26 and 28 are enlarged so that the ends of the primary electrodes 26 and 28 on the secondary electrode 72 side are different from those in the first embodiment. The second embodiment is different from the first embodiment in that it is closer to the secondary electrode 72 side, but the other points are the same and the manufacturing method is also the same.

As shown in FIG. 3B, in the third embodiment, the size of the primary electrodes 26 and 28 is reduced so that the ends of the primary electrodes 26 and 28 on the secondary electrode side 72 are different from those in the first embodiment. The second embodiment is different from the first embodiment in that it is distant from the secondary electrode 72 side, but the other points are the same, and the manufacturing method is also the same.

As shown in FIG. 3C, in the fourth embodiment, the size of the primary electrodes 26 and 28 is reduced, and the ends of the primary electrodes 26 and 28 on the side of the secondary electrode 72 and the secondary electrode 7 are formed.
2 is the same as in the first embodiment, except that the end faces of the primary electrodes 26 and 28 on the primary end face 16 side are farther from the primary electrodes 22 and 24 than in the first embodiment. Although different from the first embodiment, the other points are the same and the manufacturing method is also the same.

As shown in FIG. 4, in the fifth embodiment, the ends of the primary electrodes 26 and 28 of the fourth embodiment on the side of the secondary electrode 72 are two times larger than in the fourth embodiment. The difference from the fourth embodiment is that the second electrode 72 is extended toward the next electrode 72 by a predetermined length, but the other points are the same and the manufacturing method is also the same. In the present embodiment, the primary electrodes 26 and 2
By adjusting the position and size of 8 to predetermined positions and sizes, it is easy to adjust the input impedance and the output impedance, and to easily pull out the support point of the vibrator and lead wires.

Also in the second to fifth embodiments, the primary electrodes 26 and 28 are provided in regions where stress in the direction opposite to the stress in the region where the primary electrodes 22 and 24 are provided is provided.
The polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 26 and the primary electrode 28 is the same as the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 22 and the primary electrode 24, and the direction of application of the electric field is opposite. Therefore, the input impedance of the piezoelectric transformer 100 is reduced, so that electric energy is easily supplied from the power source 82 to the piezoelectric transformer 100, and the input electric energy can be more efficiently converted into mechanical elastic energy on the primary side a. And the output impedance further decreases, and the CFL connected to the secondary side b of the piezoelectric transformer 100
Since the voltage that can be applied to the piezoelectric transformer 90 increases, the effective boosting ratio of the piezoelectric transformer 100 can be increased.

In the second embodiment, the primary electrode 2
6 and 28, the electrode area on the primary side a is larger than that of the piezoelectric transformer 100 of the first embodiment, and the input impedance of the piezoelectric transformer 100 is correspondingly smaller. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82. Further, the electric energy supplied from the power supply 82 on the primary side a can be converted to mechanical elastic energy more efficiently than in the first embodiment. Further, since the ends of the primary electrodes 26 and 28 on the secondary electrode 72 side are closer to the secondary electrode 72 side than in the first embodiment, the region on the secondary side b is shorter in the longitudinal direction, As a result, the output impedance is further reduced. As a result, the voltage that can be applied to the CFL 90 connected to the secondary side b of the piezoelectric transformer 100 increases, so that the effective step-up ratio of the piezoelectric transformer 100 can be increased.

In the third embodiment, the primary electrode 2
Since the ends of the secondary electrodes 6 and 28 on the secondary electrode side 72 are farther from the secondary electrode 72 side than in the first embodiment, the voltage generated on the secondary side can be increased, and the step-up ratio of the piezoelectric transformer 100 can be increased. Can be larger.

(Sixth Embodiment) FIG. 5 is a diagram for explaining a piezoelectric transformer according to a sixth embodiment.
5A is a perspective view, FIG. 5B is a sectional view, FIG. 5C is a view showing a stress distribution, and FIG. 5D is a view showing an amplitude distribution.

As shown in FIGS. 5A and 5B, a primary electrode 32 is provided on the left one-third of the upper surface 12 of the rectangular parallelepiped piezoelectric ceramic substrate 10. Primary electrode 34 on the lower surface 14
Is provided, and the piezoelectric ceramic substrate 10 between the primary electrode 32 and the primary electrode 34 is polarized in the thickness direction between the upper surface 12 and the lower surface 14.

The upper surface 12 of the piezoelectric ceramic substrate 10 is further separated from the primary end face 16 by a distance of １ ／ of the length in the longitudinal direction of the piezoelectric ceramic substrate 10, from the primary end face 16 to the piezoelectric ceramic substrate 10. A primary electrode 36 is provided up to a position separated by a distance of ／ of the longitudinal length of the piezoelectric ceramic substrate 10, and a primary electrode 38 is provided on the lower surface 14 of the piezoelectric ceramic substrate 10 so as to face the primary electrode 36. The primary electrode 36 is provided separately from the primary electrode 32, and the primary electrode 38 is provided separately from the primary electrode 34. The piezoelectric ceramic substrate 10 between the primary electrode 36 and the primary electrode 38 is polarized in the thickness direction between the upper surface 12 and the lower surface 14.

The upper surface 12 of the piezoelectric ceramic substrate 10 is spaced apart from the primary end face 16 by a distance of ／ of the length in the longitudinal direction of the piezoelectric ceramic substrate 10, from the primary end face 16 to the longitudinal end of the piezoelectric ceramic substrate 10. A primary electrode 42 is provided up to a position separated by a distance of ／ of the length in the direction, and a primary electrode 44 is provided on the lower surface 14 of the piezoelectric ceramic substrate 10 so as to face the primary electrode 42. The primary electrode 42 is provided separately from the primary electrode 36, and the primary electrode 44 is provided separately from the primary electrode 38. The piezoelectric ceramic substrate 10 between the primary electrode 42 and the primary electrode 44 is polarized in the thickness direction between the upper surface 12 and the lower surface 14. The polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 32 and the primary electrode 34, the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 36 and the primary electrode 38, and the polarization direction between the primary electrode 42 and the primary electrode 44. The polarization direction of the piezoelectric ceramic substrate 10 is the same.

A secondary electrode 72 is provided on the secondary end face 18 perpendicular to the upper surface 12 and the lower surface 14, and the primary electrodes 42, 4
The piezoelectric ceramic substrate 10 between the fourth electrode 4 and the secondary electrode 72 is polarized in the longitudinal direction which is the direction in which the upper surface 12 and the lower surface 14 extend.

One end of the power supply 82 is connected to the primary electrode 32 via the connection 132, connected to the primary electrode 38 via the connection 138, and connected to the primary electrode 42 via the connection 142. The other end of the power supply 82 is connected to the primary electrode 34 via a connection 134, connected to the primary electrode 36 via a connection 136, and connected to the primary electrode 44 via a connection 144. The secondary electrode 72 has C as a load.
The other end of the CFL 90 is connected to one end of the FL 90
2 is connected to the other end.

When a voltage is applied between the primary electrodes 32 and 34 from the power source 82, an electric field is applied in the thickness direction in the left one-third region, and the longitudinal direction is displaced in the direction perpendicular to the polarization direction by the piezoelectric transverse effect. When the longitudinal vibration in the direction is excited, the piezoelectric transformer 10
0 whole vibrates. In the piezoelectric transformer of the present embodiment, driving is performed in a resonance mode in which a stress distribution of 1.5 wavelength exists between the primary end face 16 and the secondary end face 18. A voltage having a frequency equal to the frequency of the resonance in the 1.5-wavelength mode is applied from the power supply 82. In the present embodiment, a point separated to the right by a distance of 1/4 wavelength from the primary end face 16, a point separated to the right by a distance of 3/4 wavelength from the primary end face 16, and a quarter of the secondary end face 18. A support point was provided at a position separated to the left of the wavelength. Since both the primary end face 16 and the secondary end face 18 of the piezoelectric ceramic substrate 10 are open, the stress is zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 10, and the amplitude is maximized. In the present embodiment, the resonance is performed in the 1.5-wavelength mode.
C and FIG. 5D.

In the present embodiment, the primary electrode 32,
In addition to 34, primary electrodes 36, 38, 42 and 44 are further provided. Accordingly, the electrode area on the primary side a is increased, and accordingly, the input impedance of the piezoelectric transformer 100 is reduced. As a result, the piezoelectric transformer 100
Is easily supplied with electric energy from the power supply 82.

The stress in the region where the primary electrodes 32 and 34 are provided is in the direction of the upper surface 12 of the piezoelectric ceramic substrate 10, while the stress in the region where the primary electrodes 36 and 38 are provided is piezoelectric. This is the direction of the lower surface of the ceramic substrate 10 and opposite to the stress in the region where the primary electrodes 32 and 34 are provided. Primary electrode 36 and primary electrode 3
8 is the same as the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 32 and the primary electrode 34, but the direction of application of the electric field is opposite. Therefore, the primary electrodes 36, 3
When a voltage is applied between the primary electrodes 36 and 38, the piezoelectric ceramic substrate 10 between the primary electrodes 36 and 38
Vibration is performed to further increase the resonance excited by the application of a voltage between 2, 34.

Further, the stress in the region where the primary electrodes 42 and 44 are provided and the stress in the region where the primary electrodes 32 and 34 are provided are in the same direction. The polarization direction of the piezoelectric ceramic substrate 10 is the same as the polarization direction of the piezoelectric ceramic substrate 10 between the primary electrode 32 and the primary electrode 34, and the direction of application of the electric field is also the same. Therefore, the primary electrode 4
When a voltage is applied between the primary electrodes 42, 44, the primary electrodes 42, 44
The intervening piezoelectric ceramic substrate 10 vibrates so as to further increase the resonance excited when a voltage is applied between the primary electrodes 32 and 34 from the power supply 82. as a result,
On the primary side a, electric energy supplied from the power supply 82 can be more efficiently converted into mechanical elastic energy.

On the other hand, by providing the primary electrodes 42 and 44, the region on the secondary side b is shortened in the longitudinal direction.
As a result, the output impedance decreases. As described above, when the output impedance of the piezoelectric transformer 100 decreases, the voltage applied to the CFL 90 connected to the secondary electrode 72 of the piezoelectric transformer 100 increases accordingly.

Further, since the distance between the primary electrode and the secondary electrode is reduced by providing the primary electrodes 42 and 44 as in the present embodiment, the distance between the primary electrodes 42 and 44 and the secondary electrode 72 is reduced. When the piezoelectric ceramic substrate 10 is polarized in the longitudinal direction, the primary electrodes 42, 4
The absolute voltage applied during polarization is smaller than that in the case where 4 is not provided. As a result, measures for high pressure become easier,
A lower voltage power supply can also be used for the polarization.

In the present embodiment, the vibration nodes 212, 214, and 216 are used as the supporting points of the piezoelectric transformer 100, so that the vibration of the piezoelectric transformer 100 caused by supporting the piezoelectric transformer 100 is greatly inhibited. Can be smaller. Further, in the present embodiment, the connection portions 132 and 134 of the primary electrodes 32 and 34 and the electrode terminals provided at these connection portions 132 and 134 are also provided at the node 212 of the vibration, and the connection portions 13 of the primary electrodes 36 and 38 are provided.
6, 138 and the electrode terminals provided at these connection portions 136, 138 are also provided at the node 214 of the vibration, and the primary electrodes 42, 4
4 connection parts 142 and 144 and these connection parts 14
Since the electrode terminals provided at 2, 144 are also provided at the vibration node 216, it is possible to prevent the vibration from being hindered by the electrical connection portion.

Note that the method of manufacturing the piezoelectric transformer of the present embodiment is the same as that of the first embodiment.

(Seventh and Eighth Embodiments) FIG.
It is a figure for explaining the piezoelectric transformer of the 7th and 8th embodiments of the present invention, FIG. 6A is a sectional view of the piezoelectric transformer of the 7th embodiment of the present invention, and FIG. 6B is the present invention. FIG. 6C is a sectional view of a piezoelectric transformer according to an eighth embodiment of the present invention, FIG. 6C is a diagram showing a stress distribution of the piezoelectric transformer shown in FIGS. 6A and 6B, and FIG. It is a figure showing an amplitude distribution.

As shown in FIG. 6A, in the seventh embodiment, the primary electrodes 42 and 44 of the sixth embodiment are not provided, and the primary electrodes 36 and 38 and the secondary electrodes 72 are not provided. The point that the piezoelectric ceramic substrate 10 is polarized in the longitudinal direction which is the extending direction of the upper surface 12 and the lower surface 14 is different from the sixth embodiment, but the other points are the same, and the manufacturing method is also the same.

As shown in FIG. 6B, in the eighth embodiment, the size of the primary electrodes 36 and 38 of the seventh embodiment is reduced so that the ends of the primary electrodes 36 and 38 on the secondary electrode side 72 are reduced. Although the seventh embodiment is different from the seventh embodiment in that it is farther from the secondary electrode 72 than the seventh embodiment, the other points are the same and the manufacturing method is also the same.

(Ninth and Tenth Embodiments) FIG.
FIG. 19 is a perspective view of a piezoelectric transformer according to a ninth embodiment.
In the first embodiment, the secondary electrode 72 is provided on the secondary side end face 18 of the piezoelectric ceramic substrate 10. However, in the ninth embodiment, the secondary electrode 74 is provided on the upper surface 12 , A secondary electrode 76 is provided on the lower surface 41 of the piezoelectric ceramic substrate 10, and the secondary electrode 74 and the secondary electrode 76 are electrically connected to each other.
Is different from the first embodiment in that it is connected to one end of the first embodiment, but the other points are the same, and the manufacturing method is also the same.

FIG. 8 is a perspective view of a piezoelectric transformer according to the tenth embodiment. In the first embodiment, the secondary electrode 72 is connected to the secondary end face 18 of the piezoelectric ceramic substrate 10.
However, in the tenth embodiment, the first electrode 74 is provided on the upper surface 12 of the piezoelectric ceramic substrate 10 and the secondary electrode 74 is connected to one end of the CFL 90 in the first embodiment.
Although the present embodiment is different from the above embodiment, the other points are the same, and the manufacturing method is also the same.

The secondary electrode 74 is connected to the piezoelectric ceramic substrate 10
When the secondary electrode 74 is provided on the lower surface 14 of the piezoelectric ceramic substrate 10, the primary electrodes 24, 28 can be formed by the same process as that for forming the primary electrodes 22, 26. Since the secondary electrode 76 can be formed in the same step as the step of forming the
There is no need to provide a step for forming 76.

Further, by adjusting the area of the secondary electrodes 74 and 76, the distance from the primary electrodes 26 and 28 can be adjusted, and as a result, the output impedance of the piezoelectric transformer 100 can be adjusted. On the other hand, the resonance frequency of the piezoelectric transformer 100 is determined by the length of the piezoelectric ceramic substrate 10 in the longitudinal direction. Therefore, by forming the secondary electrodes 74 and 76 on at least one of the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10, the resonance frequency and the output impedance can be controlled independently. In addition, when the secondary electrodes 74 and 76 are formed on both the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10 as in the eighth embodiment, the polarization in the longitudinal direction becomes easier.

(Eleventh Embodiment) FIGS. 9A and 9B are views for explaining a piezoelectric transformer and a method of driving the same according to an eleventh embodiment. FIG. 9A is a perspective view, and FIG. 9B is a stress distribution. FIG. 9C is a diagram showing an amplitude distribution.

The present embodiment is different from the first embodiment in that a part of the primary electrode 22 is formed as a feedback electrode 23 provided so as to be electrically insulated from the primary electrode 22. Are the same, and the manufacturing method is also the same.

As described above, the feedback electrode 2 provided with a part of the primary electrode 22 electrically insulated from the primary electrode 22 is provided.
By setting the value to 3, a signal for monitoring the vibration state of the piezoelectric transformer 100 can be taken out in the form of a small signal using the feedback electrode 23, and the feedback can be applied to the piezoelectric transformer 100 using the signal. The piezoelectric transformer 100 can self-oscillate.

This self-excited oscillation can be preferably caused by connecting the phase shift circuit 86 and the amplifier circuit 84 to the feedback electrode 23 and applying the output of the amplifier circuit to the primary electrodes 22 and 24. It should be noted that a phase shift circuit 86 here is preferably a reactance circuit.

(Twelfth Embodiment) FIGS. 10A and 10B are views for explaining a piezoelectric transformer according to a twelfth embodiment and a method of driving the piezoelectric transformer. FIG. 10A is a perspective view, and FIG. FIG. 10C is a diagram showing an amplitude distribution.

In the eleventh embodiment, a part of the primary electrode 22 is the feedback electrode 23 provided electrically insulated from the primary electrode 22, but in the present embodiment, the primary electrode 22 is The present embodiment is different from the eleventh embodiment in that a part of 26 is a feedback electrode 27 provided electrically insulated from the primary electrode 26, but the other points are the same and the manufacturing method is also the same. .

In the present embodiment, as in the eleventh embodiment, a part of the primary electrode 26 is formed as a feedback electrode 27 provided electrically insulated from the primary electrode 26. A signal for monitoring the vibration state of the piezoelectric transformer 100 can be extracted in the form of a minute signal using the feedback electrode 27, and the signal can be used to
Feedback can be applied to the piezoelectric transformer 1
00 can be self-oscillated.

(Thirteenth Embodiment) FIG.
11A is a perspective view, FIG. 11B is a sectional view, FIG. 11C is a view showing a stress distribution, and FIG. 11D is a view showing an amplitude distribution.

As shown in FIGS. 11A and 11B, the left quarter of the upper surface 302 of the rectangular parallelepiped piezoelectric ceramic substrate 300 is formed.
Is provided with a primary electrode 322, and the primary electrode 322
A primary electrode 324 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 has an upper surface 3
It is polarized in the thickness direction between the bottom surface 02 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 306 by a distance of a quarter of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 306.
A primary electrode 326 is provided up to a position separated by a distance of 3/8 of the length in the longitudinal direction of 00, and a primary electrode 328 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 326. The primary electrode 326 is provided separately from the primary electrode 322, and the primary electrode 328 is provided separately from the primary electrode 324. The piezoelectric ceramic substrate 300 between the primary electrode 326 and the primary electrode 328 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

Upper surface 302 of piezoelectric ceramic substrate 300
A primary electrode 422 is provided in a quarter area on the right side of
Piezoelectric ceramic substrate 300 facing primary electrode 422
A primary electrode 424 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 308 by a distance of １ ／ of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 308.
A primary electrode 426 is provided up to a position separated by a distance of ／ of the length in the longitudinal direction of 00, and a primary electrode 428 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 426. The primary electrode 426 is provided separately from the primary electrode 422, and the primary electrode 428 is provided separately from the primary electrode 424. The piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 and the primary electrode 3
Piezoelectric ceramic substrate 3 between first electrode 26 and primary electrode 328
The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424 and the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428 are the same. Same but
The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 and the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424 are opposite, and the primary electrode 326 and the primary electrode 326 are opposite. The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 426 is opposite to the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428.

The upper surface 302 of the piezoelectric ceramic substrate 300
Further, a secondary electrode 374 is provided in the center of the piezoelectric ceramic substrate 300 in the longitudinal direction, and a secondary electrode 376 is provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374. Primary electrodes 326, 3
The piezoelectric ceramic substrate 300 between the second electrode 28 and the secondary electrodes 374 and 376 is polarized in the longitudinal direction which is the direction in which the upper surface 302 and the lower surface 304 extend. Primary electrode 42
The piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 is polarized in the longitudinal direction which is the extending direction of the upper surface 302 and the lower surface 304. The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrodes 326 and 328 and the secondary electrodes 374 and 376 and the primary electrode 42
The directions of polarization of the piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 are the same.

One end of the power supply 82 is connected to the primary electrode 322 via the connection portion 522, connected to the primary electrode 328 via the connection portion 528, and connected to the primary electrode 328 via the connection portion 628.
28, and the primary electrode 422 via the connection portion 622.
Is connected to The other end of the power supply 82 is connected to the primary electrode 324 via the connection 524, connected to the primary electrode 326 via the connection 526, connected to the primary electrode 426 via the connection 626, and connected via the connection 624. Connected to the primary electrode 424.

The secondary electrode 374 and the secondary electrode 376 are electrically connected, and both are connected to one end of the CFL 90.
The other end of FL is connected to the other end of power supply 82.

In this embodiment, a piezoelectric ceramic substrate 300 having a length in the longitudinal direction of 40 mm, a width of 5 mm, and a thickness of 1 mm was used. The present embodiment has a shape in which the piezoelectric transformer of the first embodiment is provided symmetrically with respect to the secondary electrodes 374 and 376. The piezoelectric transformer 100 includes the piezoelectric transformer of the first embodiment. As compared with the case of the transformer, twice as much energy can be supplied, and the input voltage can be further reduced. In addition, in the first embodiment, the secondary electrode 72 is provided on the secondary end face 18,
In the present embodiment, piezoelectric ceramic substrate 300
A secondary electrode 374 is provided at the center of the upper surface 302 of the piezoelectric ceramic substrate 300, and a secondary electrode 376 is also provided at the center of the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374.

In this embodiment, the vibration nodes 222, 224, 226, and 228 are connected to the piezoelectric transformer 100.
Therefore, the inhibition of the vibration of the piezoelectric transformer 100 caused by supporting the piezoelectric transformer 100 can be extremely reduced.

Note that the method of manufacturing the piezoelectric transformer of the present embodiment is the same as that of the first embodiment.

(Fourteenth Embodiment) FIG. 12 shows a fourteenth embodiment.
12A is a perspective view, FIG. 12B is a cross-sectional view, FIG. 12C is a diagram showing a stress distribution, and FIG. 12D is a diagram showing an amplitude distribution. FIG. 13 is a diagram showing the relationship between the input voltage to the piezoelectric transformer of the present embodiment and the brightness of the cold cathode tube.

As shown in FIGS. 12A and 12B, a primary electrode 52 is provided in a left 3/4 region of the upper surface 12 of the piezoelectric ceramic substrate 10 having a rectangular parallelepiped shape. Primary electrode 54 is also provided on lower surface 14
Are provided, and the piezoelectric ceramic substrate 10 between the primary electrode 52 and the primary electrode 54 is polarized in the thickness direction between the upper surface 12 and the lower surface 14. However, an area (area c) of the piezoelectric ceramic substrate 10 from the primary end face 16 to a distance of half the length of the piezoelectric ceramic substrate 10 in the longitudinal direction.
And the distance from the primary end face 16 to half the length of the piezoelectric ceramic substrate 10 in the longitudinal direction, and the primary end face 1
6 to 3 which is the length of the piezoelectric ceramic substrate 10 in the longitudinal direction.
The polarization direction of the region (region d) of the piezoelectric ceramic substrate 10 up to the distance of / 4 is the opposite direction.

A secondary electrode 72 is provided on the secondary end face 18 perpendicular to the upper surface 12 and the lower surface 14, and the primary electrodes 52, 5
The piezoelectric ceramic substrate 10 between the fourth electrode 4 and the secondary electrode 72 is polarized in the longitudinal direction which is the direction in which the upper surface 12 and the lower surface 14 extend.

One end of the power supply 82 is connected to the primary electrode 22 via the connection 152, and the other end of the power supply 82 is connected to the connection 154.
Is connected to the primary electrode 54 via the. Secondary electrode 72
Is connected to one end of CFL 90 as a load, and CFL 9
0 is connected to the other end of the power supply 82.

When a voltage is applied between the primary electrodes 52 and 54 from the power source 82, an electric field is applied in the thickness direction in the left half, and the longitudinal vibration in the longitudinal direction is caused by the piezoelectric transverse effect displaced in the direction perpendicular to the polarization direction. When excited, the entire piezoelectric transformer 100 vibrates. In the piezoelectric transformer according to the present embodiment, driving is performed in a resonance mode in which a stress distribution of one wavelength exists between the primary end face 16 and the secondary end face 18. From the power supply 82, a voltage having a frequency equal to the frequency of the resonance in the one-wavelength mode is applied. In the present embodiment, the primary side end face 16
A support point is provided at a location that is 右側 wavelength away from the right side and a location that is １ ／ wavelength left from the secondary end face 18. Since both the primary end face 16 and the secondary end face 18 of the piezoelectric ceramic substrate 10 are open, the stress is zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 10, and the amplitude is maximized. In the present embodiment, since resonance is performed in the one-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 12C and 12D, respectively.

In the present embodiment, the primary electrode 52,
54 extends from the primary side end surface 16 to a position at a distance of ／ of the longitudinal length of the piezoelectric ceramic substrate 10 from the primary side end surface 16. Therefore, the primary side (c +
The electrode area d) is larger than that of the conventional piezoelectric transformer of FIG. 27, and the input impedance of the piezoelectric transformer 100 is correspondingly smaller. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82.

The stress in the region c is in the direction of the upper surface 12 of the piezoelectric ceramic substrate 10, while the stress in the region d is in the direction of the lower surface of the piezoelectric ceramic substrate 10 and is in the opposite direction to the stress in the region c. It is. The polarization direction of the region c is
Although the direction of polarization of the region d is opposite, the direction of application of the electric field is the same. Therefore, the primary electrodes 52, 5
When a voltage is applied across the area 4, the piezoelectric ceramic substrate 10 in the region d vibrates so as to further increase the resonance excited by the application of the voltage from the power source 82 to the region c. As a result, the electrical energy supplied from the power supply 82 on the primary side (c + d) can be more efficiently converted into mechanical elastic energy.

On the other hand, by providing the region d, the region f on the secondary side is shortened in the longitudinal direction, and as a result, the output impedance is reduced. When the output impedance of the piezoelectric transformer 100 decreases as described above, the CFL 9 connected to the secondary electrode 72 of the piezoelectric transformer 100
The voltage applied to 0 increases accordingly.

As described above, the primary electrodes 52 and 54 are extended to the region d where the stress in the direction opposite to the stress in the region c is generated, the polarization direction of the region c is made different from the polarization direction of the region d, and By setting the application direction to be the same, the input impedance of the piezoelectric transformer 100 is reduced, electric power is easily supplied from the power supply 82 to the piezoelectric transformer 100, and the input electric energy is more efficiently used on the primary side (c + d). Since it becomes possible to convert the energy into mechanical elastic energy, the output impedance is further reduced, and the voltage that can be applied to the CFL 90 connected to the secondary side f of the piezoelectric transformer 100 is increased. The boost ratio can be increased.

Further, as described above, by extending the primary electrodes 52 and 54 to the region d as in the present embodiment, the distance between the primary electrodes 52 and 54 and the secondary electrode 72 is shortened. , 54 and the secondary electrode 72 are polarized in the longitudinal direction, as compared with the conventional piezoelectric transformer of FIG. In addition, the absolute voltage applied at the time of polarization decreases. As a result, it is easy to take measures against a high voltage, and a low-voltage power supply can be used.

It should be noted that the present embodiment works effectively even when the load connected to the secondary side b of the piezoelectric transformer is the CFL 90 as in the present embodiment.
This is the same as the embodiment.

Further, in the present embodiment, by adjusting the size and the like of the primary electrodes 52 and 54, not only the step-up ratio of the piezoelectric transformer 100 but also the output impedance can be adjusted, so that the degree of freedom in design can be improved. Is improved.

From the piezoelectric ceramic fired body manufactured in the same manner as in the first embodiment, the length in the longitudinal direction was 2 mm.
A rectangular parallelepiped having a size of 0 mm, a width of 5 mm, and a thickness of 1 mm was cut out to obtain a piezoelectric ceramic substrate 10. Next, a silver electrode was applied to the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10 by screen printing, and was also applied to the secondary side end surface 18 by brush painting. Then in the air,
Baking is performed at 600 ° C., and as shown in FIG. 14, a polarizing electrode 521 is provided on the upper surface 12 of the region c of the piezoelectric ceramic substrate 10, and a polarizing electrode 541 is provided on the lower surface 14 of the region c of the piezoelectric ceramic substrate 10. Piezoelectric ceramic substrate 1
The polarization electrode 523 is provided on the upper surface 12 of the region d of the zero, the polarization electrode 543 is provided on the lower surface 14 of the region d of the piezoelectric ceramic substrate 10, and the secondary end surface 18 of the piezoelectric ceramic substrate 10 is provided.
Were formed with secondary electrodes 72, respectively.

Thereafter, the polarization electrode 541 and the polarization electrode 5
23 is connected to the positive electrode of the power supply for polarization, and
21 and the polarization electrode 543 are connected to a polarization power supply negative electrode.
By applying 2 kV in silicone oil at 00 ° C, c
Polarization in the thickness direction of the region and the d region was performed. afterwards,
The polarization electrode 521 and the polarization electrode 523 were connected by a conductor to form the primary electrode 52, and the polarization electrode 541 and the polarization electrode 543 were connected by a conductor to form the primary electrode 54. Then, the primary electrode 52 and the primary electrode 54 are connected to the power supply positive electrode for polarization, and the secondary electrode 72 is connected to the power supply negative electrode for polarization, and 10 kV is applied in silicone oil at 100 ° C. Was performed in the longitudinal direction.

Thereafter, one end of the power supply 82 was connected to the primary electrode 52 via the connection 152, and the other end of the power supply 82 was connected to the primary electrode 54 via the connection 154. Secondary electrode 72
Was connected to one end of the CFL 90, and the other end of the CFL 90 was connected to the other end of the power supply 82. The CFL 90 has a length of 2 used for an A4 notebook personal computer.
Those having a diameter of 25 mm and a diameter of 2.6 mm were used.

At the vibration nodes 202 and 204, the power supply 82
Hz, a relationship between the input voltage to the piezoelectric transformer 100 and the luminance of the CFL was measured. Figure 1 shows the results.
3 (see curve P '). In FIG. 13, the piezoelectric transformer 100 shown in FIG. 1 is not provided with the primary electrodes 26 and 28, and the piezoelectric ceramic substrate 10 between the primary electrodes 22, 24 and the secondary electrode 72 is polarized in the longitudinal direction. (See curve Q ') is also shown for comparison. In the piezoelectric transformer 100 shown in FIG.
In the piezoelectric transformer without the 6 and 28, an input voltage of 66 V _rms was required to obtain a luminance of 27,000 cd / m ² in the CFL 90.
The same luminance was obtained at an input voltage of 0 V _rms .

Note that the lighting of the CFL 90 is approximately 15 V _rms.
Could be started by applying an input voltage of

(Fifteenth and Sixteenth Embodiments) FIG.
FIG. 5 is a view for explaining the piezoelectric transformers of the fifteenth and sixteenth embodiments, and FIG.
15B is a sectional view of the piezoelectric transformer according to the embodiment of FIG.
FIG. 15C is a cross-sectional view of a piezoelectric transformer according to a sixteenth embodiment of the present invention, FIG. 15C is a diagram showing a stress distribution of the piezoelectric transformer shown in FIGS. 15A and 15B, and FIG.
15A and 15B are diagrams illustrating amplitude distributions of the piezoelectric transformer illustrated in FIGS.

As shown in FIG. 15A, in the fifteenth embodiment, the size of the primary electrodes 52 and 54 of the region d and the piezoelectric ceramic substrate 10 are increased so that the end of the region d is larger than that of the first embodiment. The fourth embodiment differs from the fourteenth embodiment in that it is closer to the secondary electrode 72, but the other points are the same, and the manufacturing method is also the same.

As shown in FIG. 15B, in the sixteenth embodiment, the primary electrodes 52 and 54 of the region d and the piezoelectric ceramic substrate 10 are made smaller, and the end of the region d is made smaller than in the first embodiment. The fourth embodiment is different from the fourteenth embodiment in that it is distant from the secondary electrode 72, but the other points are the same and the manufacturing method is also the same.

Also in the fifteenth and sixteenth embodiments, the primary electrodes 52 and 54 are extended to the region d where the stress in the direction opposite to the stress in the region c is generated, and the polarization direction of the region c is changed. By making the direction of polarization different from the direction of polarization and making the direction of application of the electric field the same, the input impedance of the piezoelectric transformer 100 is reduced, and electric energy is easily supplied from the power source 82 to the piezoelectric transformer 100.
On the primary side (c + d), the input electric energy can be more efficiently converted into mechanical elastic energy, and the output impedance can be reduced, so that it can be applied to the CFL 90 connected to the secondary side f of the piezoelectric transformer 100. Since the voltage increases, the effective boosting ratio of the piezoelectric transformer 100 can be increased.

In the fifteenth embodiment, since the primary electrodes 52 and 54 are enlarged, the primary side (c +
d) The piezoelectric transformer 1 of the fourteenth embodiment having an electrode area of
Thus, the input impedance of the piezoelectric transformer 100 decreases accordingly. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82. In addition, the primary side (c +
In d), the electric energy supplied from the power supply 82 can be more efficiently converted into mechanical elastic energy than in the fourteenth embodiment. Further, the primary electrodes 52 and 5
4 is closer to the secondary electrode 72 side than in the fourteenth embodiment, the area of the secondary side f is shorter in the longitudinal direction, and as a result, the output impedance is reduced. It becomes even smaller. As a result, the voltage that can be applied to the CFL 90 connected to the secondary side f of the piezoelectric transformer 100 increases, so that the effective boosting ratio of the piezoelectric transformer 100 can be increased.

In the sixteenth embodiment, the ends of the primary electrodes 52 and 54 on the secondary electrode side 72 are farther from the secondary electrode 72 side than in the fourteenth embodiment. The generated voltage can be increased, and the step-up ratio of the piezoelectric transformer 100 can be further increased.

(Seventeenth Embodiment) FIG. 16 is a view for explaining a piezoelectric transformer according to a seventeenth embodiment of the present invention. FIG. 16A is a perspective view, FIG. 16B is a sectional view, and FIG.
6C is a diagram showing a stress distribution, and FIG. 16D is a diagram showing an amplitude distribution.

As shown in FIGS. 16A and 16B, a primary electrode 56 is provided in a left 5/6 region of the upper surface 12 of the piezoelectric ceramic substrate 10 having a rectangular parallelepiped shape. The primary electrode 58 is also provided on the lower surface 14.
Is provided, and the piezoelectric ceramic substrate 10 between the primary electrode 56 and the primary electrode 58 is polarized in the thickness direction between the upper surface 12 and the lower surface 14. However, 1/3 of the longitudinal length of the piezoelectric ceramic substrate 10 from the primary end face 16
The direction of polarization of the region (region c) of the piezoelectric ceramic substrate 10 up to a distance of 1/3, and the distance from the primary end 16 to the length in the longitudinal direction of the piezoelectric ceramic substrate 10 and 1/3 of the length of the piezoelectric ceramic substrate 10 from the primary end 16 The polarization direction of the region (region d) of the piezoelectric ceramic substrate 10 up to a distance of 2/3 of the length in the longitudinal direction is the opposite direction. The polarization direction of the region (region c) of the piezoelectric ceramic substrate 10 from the primary end face 16 to a distance of １ ／ of the length in the longitudinal direction of the piezoelectric ceramic substrate 10, and the polarization direction of the piezoelectric ceramic substrate 10 from the primary end face 16. The polarization direction of the region (region e) of the piezoelectric ceramic substrate 10 from the distance of 2/3 of the longitudinal length to the distance of 5/6 of the longitudinal length of the piezoelectric ceramic substrate 10 from the primary end face 16 is the same. It is.

A secondary electrode 72 is provided on the secondary side end surface 18 perpendicular to the upper surface 12 and the lower surface 14, and the primary electrodes 56, 5
The piezoelectric ceramic substrate 10 between the secondary electrode 8 and the secondary electrode 72 is polarized in the longitudinal direction in which the upper surface 12 and the lower surface 14 extend.

One end of the power supply 82 is connected to the primary electrode 56 via the connection 156, and the other end of the power supply 82 is connected to the connection 158.
Is connected to the primary electrode 58 via the. Secondary electrode 72
Is connected to one end of CFL 90 as a load, and CFL 9
0 is connected to the other end of the power supply 82.

When a voltage is applied between the primary electrodes 56 and 58 from the power source 82, an electric field is applied in the thickness direction in the left third area c, and the piezoelectric effect is applied in a direction perpendicular to the polarization direction. When the longitudinal vibration in the longitudinal direction is excited, the piezoelectric transformer 1
00 whole vibrates. In the piezoelectric transformer of the present embodiment, driving is performed in a resonance mode in which a stress distribution of 1.5 wavelength exists between the primary end face 16 and the secondary end face 18. Power supply 82
Therefore, a voltage having a frequency equal to the frequency of the resonance in the 1.5-wavelength mode is applied. Since both the primary end face 16 and the secondary end face 18 of the piezoelectric ceramic substrate 10 are open, the stress is zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 10, and the amplitude is maximized.
In the present embodiment, since resonance is performed in the 1.5-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 16C and 16D, respectively.

In the present embodiment, the primary electrode 56,
58 extends from the primary end face 16 to a position at a distance of か ら of the longitudinal length of the piezoelectric ceramic substrate 10 from the primary end face 16. Therefore, the primary side (c +
The electrode area of d) increases, and the input impedance of the piezoelectric transformer 100 decreases accordingly. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82.

The stress in the region c is in the direction of the upper surface 12 of the piezoelectric ceramic substrate 10, while the stress in the region d is in the direction of the lower surface 14 of the piezoelectric ceramic substrate 10, which is opposite to the stress in the region c. Direction. The polarization direction of the region c is opposite to the polarization direction of the region d, but the direction of application of the electric field is the same. Therefore, the primary electrode 5
When a voltage is applied between 6 and 58, the piezoelectric ceramic substrate 10 in the region d vibrates so as to further increase the resonance excited by the application of the voltage from the power source 82 to the region c. As a result, the electrical energy supplied from the power supply 82 on the primary side (c + d) can be more efficiently converted into mechanical elastic energy.

Further, the stress in the region c and the stress in the region e are in the same direction, the polarization direction in the region c is the same as the polarization direction in the region e, and the direction of application of the electric field is also in the same direction. Therefore, when a voltage is applied between the primary electrodes 56 and 58 from the power supply 82, the piezoelectric ceramic substrate 10 in the region e
Vibration is performed to further increase the resonance excited by applying a voltage from 2 to the region c. As a result, the electric energy supplied from the power supply 82 on the primary side (c + d + e) can be more efficiently converted into mechanical elastic energy.

On the other hand, by providing the region e, the region f on the secondary side is shortened in the longitudinal direction, and as a result, the output impedance is reduced. When the output impedance of the piezoelectric transformer 100 decreases as described above, the CFL 9 connected to the secondary electrode 72 of the piezoelectric transformer 100
The voltage applied to 0 increases accordingly.

Further, since the distance between the primary electrode and the secondary electrode is shortened by providing the region e as in the present embodiment, the primary electrodes 56 and 58 and the secondary electrode 72 are provided.
When the piezoelectric ceramic substrate 10 is polarized in the longitudinal direction, the absolute voltage applied during polarization is smaller than when the region e is not provided. As a result, it is easy to take measures against a high voltage, and a low-voltage power supply can be used.

The method of manufacturing the piezoelectric transformer according to the present embodiment is the same as that of the fourteenth embodiment.

(Eighteenth and nineteenth embodiments) FIG. 1
FIG. 7 is a view for explaining piezoelectric transformers according to the eighteenth and nineteenth embodiments of the present invention. FIG. 17A is a cross-sectional view of the piezoelectric transformer according to the eighteenth embodiment of the present invention.
FIG. 17B is a cross-sectional view of a piezoelectric transformer according to a nineteenth embodiment of the present invention. FIG. 17C is a diagram showing a stress distribution of the piezoelectric transformer shown in FIGS. 17A and 17B.
FIG. 17B is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIGS. 17A and 17B.

As shown in FIG. 17A, the eighteenth embodiment differs from the seventeenth embodiment in that the region e of the seventeenth embodiment is not provided, but the other points are the same. Yes, the manufacturing method is the same.

As shown in FIG. 17B, in the nineteenth embodiment, the region d of the eighteenth embodiment is reduced, and the end of the region d on the side of the secondary electrode 72 is changed to the eighteenth embodiment. The present embodiment is different from the eighteenth embodiment in that it is farther from the secondary electrode 72 than in the embodiment, but the other points are the same and the manufacturing method is also the same.

(Twentieth and Twentieth Embodiments) FIG.
FIG. 8 is a perspective view of a piezoelectric transformer according to a twentieth embodiment. In the fourteenth embodiment, the secondary electrode 72 is provided on the secondary side end face 18 of the piezoelectric ceramic substrate 10,
In the twentieth embodiment, the secondary electrode 74 is provided on the upper surface 12 of the piezoelectric ceramic substrate 10, the secondary electrode 76 is provided on the lower surface 14 of the piezoelectric ceramic substrate 10, and the secondary electrode 74 and the secondary electrode 76 are electrically connected. Are electrically connected, and both are C
The difference from the fourteenth embodiment is that it is connected to one end of the FL 90, but the other points are the same, and the manufacturing method is also the same.

FIG. 19 is a perspective view of a piezoelectric transformer according to the twenty-first embodiment. In the fourteenth embodiment,
Although the secondary electrode 72 is provided on the secondary end face 18 of the piezoelectric ceramic substrate 10, in the twenty-first embodiment, the secondary electrode 74 is provided on the upper surface 12 of the piezoelectric ceramic substrate 10, and the secondary electrode 74 is provided on the CFL 90. Is different from the fourteenth embodiment in that it is connected to one end of
The same applies to the manufacturing method.

The secondary electrode 74 is connected to the piezoelectric ceramic substrate 10
When the secondary electrode 74 is provided on the lower surface 14 of the piezoelectric ceramic substrate 10, the secondary electrode 74 can be formed in the same process as the process for forming the primary electrode 52. Since the secondary electrode 76 can be formed in the same process as that described above, it is not necessary to provide a new process for forming the secondary electrodes 74 and 76.

By adjusting the area of the secondary electrodes 74 and 76, the distance between the secondary electrodes 74 and 76 can be adjusted. As a result, the output impedance of the piezoelectric transformer 100 can be adjusted. On the other hand, the resonance frequency of the piezoelectric transformer 100 is determined by the length of the piezoelectric ceramic substrate 10 in the longitudinal direction. Therefore, by forming the secondary electrodes 74 and 76 on at least one of the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10, the resonance frequency and the output impedance can be controlled independently. In addition, when the secondary electrodes 74 and 76 are formed on both the upper surface 12 and the lower surface 14 of the piezoelectric ceramic substrate 10 as in the twentieth embodiment, the polarization in the longitudinal direction becomes easier.

(Twenty-second Embodiment) FIG.
FIG. 20A is a perspective view, FIG. 20B is a diagram illustrating a stress distribution, and FIG. 20C is a diagram illustrating an amplitude distribution.

The fourteenth embodiment is different from the fourteenth embodiment in that a part of the primary electrode 52 in the region c is used as a feedback electrode 53 provided so as to be electrically insulated from the primary electrode 52. Although different, the other points are the same, and the manufacturing method is also the same.

As described above, the feedback electrode 5 provided with a part of the primary electrode 52 electrically insulated from the primary electrode 52 is provided.
By setting 3, it is possible to take out a signal for monitoring the vibration state of the piezoelectric transformer 100 in the form of a small signal using the feedback electrode 53, and to feed back the signal to the piezoelectric transformer 100 using the signal. The piezoelectric transformer 100 can self-oscillate.

The self-excited oscillation can be preferably caused by connecting the phase shift circuit 86 and the amplifier circuit 84 to the feedback electrode 53 and applying the output of the amplifier circuit to the primary electrodes 52 and 54.

(Twenty-third Embodiment) FIGS. 21A and 21B are views for explaining a piezoelectric transformer according to a twenty-third embodiment and a method of driving the piezoelectric transformer. FIG. 21A is a perspective view, and FIG. 21B is a view showing a stress distribution. FIG. 21C is a diagram showing an amplitude distribution.

In the twenty-second embodiment, a part of the primary electrode 52 in the region c is a feedback electrode 53 provided so as to be electrically insulated from the primary electrode 52. Is a feedback electrode 5 provided by electrically insulating a part of the primary electrode 52 in the region d from the primary electrode 52.
5 is different from the twenty-second embodiment, but the other points are the same, and the manufacturing method is also the same.

In this embodiment, as in the twenty-second embodiment, a part of the primary electrode 52 is formed as a feedback electrode 55 provided electrically insulated from the primary electrode 52. Using the feedback electrode 55, a signal for monitoring the vibration state of the piezoelectric transformer 100 can be extracted in the form of a minute signal.
Feedback can be applied to the piezoelectric transformer 1
00 can be self-oscillated.

(Twenty-fourth Embodiment) FIG. 22 shows a twenty-fourth embodiment.
FIG. 22A is a perspective view, FIG. 22B is a cross-sectional view, FIG. 22C is a view showing a stress distribution, and FIG. 22D is a view showing an amplitude distribution.

As shown in FIGS. 22A and 22B, a primary electrode 352 is provided on the left 3/8 region of the upper surface 302 of the rectangular parallelepiped piezoelectric ceramic substrate 300. The primary electrode 352 is opposed to the primary electrode 352. A primary electrode 354 is also provided on the lower surface 304, and the piezoelectric ceramic substrate 300 between the primary electrode 352 and the primary electrode 354 is disposed on the upper surface 30.
2 and the lower surface 304 are polarized in the thickness direction.
However, the piezoelectric ceramic substrate 3
The direction of polarization of the region (region c) of the piezoelectric ceramic substrate 300 up to a distance of 1/4 of the length in the longitudinal direction of 00 and the length of 1/4 of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 306. The polarization direction of the region (region d) of the piezoelectric ceramic substrate 300 from the distance to the distance of ３ of the length in the longitudinal direction of the piezoelectric ceramic substrate 300 from the primary side end surface 306 is the opposite direction.

Upper surface 302 of piezoelectric ceramic substrate 300
A primary electrode 452 is provided in a region on the right-hand side of the の, and a primary electrode 454 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 452.
The piezoelectric ceramic substrate 3 between the first electrode 454 and the first electrode 454
00 is polarized in the thickness direction between the upper surface 302 and the lower surface 304. However, the polarization direction of the region (region c ′) of the piezoelectric ceramic substrate 300 from the primary end surface 308 to a distance of １ ／ of the length in the longitudinal direction of the piezoelectric ceramic substrate 300, and the piezoelectric ceramic substrate 300 from the primary end surface 308 Of the piezoelectric ceramic substrate 300 from a distance of 1/4 of the longitudinal length of the piezoelectric ceramic substrate 3000 to a distance of 3/8 of the longitudinal length of the piezoelectric ceramic substrate 3000 from the primary end face 308.
The polarization direction of the region (region d ′) is the opposite direction.

The polarization direction of the piezoelectric ceramic substrate 300 in the region c is opposite to the polarization direction of the piezoelectric ceramic substrate 300 in the region c ′, and the polarization direction of the piezoelectric ceramic substrate 300 in the region d and the piezoelectric direction of the region d ′ are different. The direction is opposite to the polarization direction of the ceramic substrate 300.

Upper surface 302 of piezoelectric ceramic substrate 300
Further, a secondary electrode 374 is provided in the center of the piezoelectric ceramic substrate 300 in the longitudinal direction, and a secondary electrode 376 is provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374. Primary electrodes 352, 3
Piezoelectric ceramic substrate 300 between 54 and secondary electrodes 374, 376 is polarized in the longitudinal direction, which is the direction in which upper surface 302 and lower surface 304 extend. Primary electrode 45
The piezoelectric ceramic substrate 300 between 2, 454 and the secondary electrodes 374, 376 is polarized in the longitudinal direction which is the extending direction of the upper surface 302 and the lower surface 304. The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrodes 352 and 354 and the secondary electrodes 374 and 376 and the primary electrode 45
The polarization direction of the piezoelectric ceramic substrate 300 between the second electrodes 454 and the secondary electrodes 374 376 is the same.

One end of the power supply 82 is connected to the primary electrode 352 via the connection portion 552, and is connected to the primary electrode 452 via the connection portion 652. The other end of the power supply 82 is a connection unit 5
Connected to the primary electrode 354 via the
4 and is connected to the primary electrode 454. The secondary electrodes 374 and 376 are electrically connected to each other to
0, and the other end of the CFL 90 is connected to the other end of the power supply 82.

In the present embodiment, a piezoelectric ceramic substrate 300 having a length in the longitudinal direction of 40 mm, a width of 5 mm, and a thickness of 1 mm was used. This embodiment has a shape in which the piezoelectric transformer of the fourteenth embodiment is provided symmetrically with respect to the secondary electrodes 374 and 376. The piezoelectric transformer 100 has the piezoelectric transformer of the fourteenth embodiment. As compared with the case of a transformer, twice as much energy can be supplied, and the input voltage can be further reduced. Note that, in the fourteenth embodiment, the secondary electrode 72 is provided on the secondary side end face 18, but in the present embodiment, the piezoelectric ceramic substrate 3
A secondary electrode 374 is provided at the center of the upper surface 302 of the substrate 00, and a secondary electrode 376 is provided at the center of the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374.

The method of manufacturing the piezoelectric transformer according to the present embodiment is the same as that of the fourteenth embodiment.

(Twenty-Fifth Embodiment) FIG.
23A is a perspective view, FIG. 23B is a sectional view, FIG. 23C is a view showing a stress distribution, and FIG. 23D is a view showing an amplitude distribution.

As shown in FIGS. 23A and 23B, the left one-third of the upper surface 302 of the rectangular parallelepiped piezoelectric ceramic substrate 300 is formed.
Is provided with a primary electrode 322, and the primary electrode 322
A primary electrode 324 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 has an upper surface 3
It is polarized in the thickness direction between the bottom surface 02 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 306 by a distance of 1/3 of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 306.
A primary electrode 326 is provided up to a position separated by a distance of 5/12 of the length in the longitudinal direction of 00, and a primary electrode 328 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 326. The primary electrode 326 is provided separately from the primary electrode 322, and the primary electrode 328 is provided separately from the primary electrode 324. The piezoelectric ceramic substrate 300 between the primary electrode 326 and the primary electrode 328 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
A primary electrode 422 is provided in a 1/3 region on the right side of
Piezoelectric ceramic substrate 300 facing primary electrode 422
A primary electrode 424 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 308 by a distance of 1/3 of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 308.
A primary electrode 426 is provided up to a position separated by a distance of 5/12 of the length in the longitudinal direction of 00, and a primary electrode 428 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 426. The primary electrode 426 is provided separately from the primary electrode 422, and the primary electrode 428 is provided separately from the primary electrode 424. The piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 and the primary electrode 3
Piezoelectric ceramic substrate 3 between first electrode 26 and primary electrode 328
00, the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424, and the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428 are all the same. .

The upper surface 302 of the piezoelectric ceramic substrate 300
Further, a secondary electrode 374 is provided in the center of the piezoelectric ceramic substrate 300 in the longitudinal direction, and a secondary electrode 376 is provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374. Primary electrodes 326, 3
The piezoelectric ceramic substrate 300 between the second electrode 28 and the secondary electrodes 374 and 376 is polarized in the longitudinal direction which is the direction in which the upper surface 302 and the lower surface 304 extend. Primary electrode 42
The piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 is polarized in the longitudinal direction which is the extending direction of the upper surface 302 and the lower surface 304. The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrodes 326 and 328 and the secondary electrodes 374 and 376 and the primary electrode 42
The direction of polarization of the piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 is opposite.

One end of the power source 82 is connected to the primary electrode 322 via the connection portion 522, connected to the primary electrode 328 via the connection portion 528, and connected to the primary electrode 328 via the connection portion 628.
28, and the primary electrode 422 via the connection portion 622.
Is connected to The other end of the power supply 82 is connected to the primary electrode 324 via the connection 524, connected to the primary electrode 326 via the connection 526, connected to the primary electrode 426 via the connection 626, and connected via the connection 624. Connected to the primary electrode 424.

The secondary electrode 374 and the secondary electrode 376 are electrically connected, and both are connected to one end of the CFL 90.
The other end of the CFL 90 is connected to the other end of the power supply 82.

In the present embodiment, the primary side end surface 30
Driving is performed in a resonance mode in which a stress distribution of 1.5 wavelength exists between 6 and the primary side end surface 308. A voltage having a frequency equal to the resonance frequency of the 1.5 wavelength mode is applied from the power supply 82. Both ends 30 of piezoelectric ceramic substrate 300
Since both 6 and 308 are open, the stress becomes zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 300, and the amplitude becomes maximum. In the present embodiment, since resonance is performed in the 1.5 wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 23C and 23D, respectively.

The stress, polarization direction and electric field direction of the region where the primary electrodes 322 and 324 are provided and the primary electrodes 422 and 4
Since the stress, the polarization direction, and the electric field direction in the region where the first electrode 24 is provided are all the same, the vibration excited by the application of the voltage from the power source 82 between the primary electrodes 322 and 324 and the first electrode 422 and 424 Together with the vibration excited by the application of the voltage from the power supply 82 to the vibrations so as to further increase the mutual vibration.

The stress in the area where the primary electrodes 326 and 328 are provided is opposite to the stress in the area where the primary electrodes 322 and 324 are provided and the stress in the area where the primary electrodes 422 and 424 are provided. is there. Primary electrode 32
The polarization directions of the regions where the primary electrodes 322 and 324 are provided are the same as the polarization directions of the regions where the primary electrodes 322 and 324 are provided and the regions where the primary electrodes 422 and 424 are provided. The direction in which the electric field is applied to the region where the primary electrodes 326 and 328 are provided depends on the direction of the primary electrode 32.
The direction in which the electric field is applied to the region where the secondary electrodes 324 are provided is opposite to the direction in which the electric field is applied to the region where the primary electrodes 422 and 424 are provided. Therefore, the power supply 82
When a voltage is applied between the primary electrodes 326 and 328 from
Piezoelectric ceramic substrate 30 between primary electrodes 326 and 328
0 is the vibration excited when a voltage is applied from the power supply 82 between the primary electrodes 322 and 324 and the primary electrode 42
Vibration is performed to further increase the vibration excited by the application of the voltage from the power supply 82 between 2, 424.

The stress in the area where the primary electrodes 426 and 428 are provided is opposite to the stress in the area where the primary electrodes 322 and 324 are provided and the stress in the area where the primary electrodes 422 and 424 are provided. is there. Primary electrode 42
The polarization directions of the regions where the primary electrodes 322 and 324 are provided are the same as the polarization directions of the regions where the primary electrodes 322 and 324 are provided. The direction in which the electric field is applied to the region where the primary electrodes 426 and 428 are provided depends on the primary electrode 32.
The direction in which the electric field is applied to the region where the secondary electrodes 324 are provided is opposite to the direction in which the electric field is applied to the region where the primary electrodes 422 and 424 are provided. Therefore, the power supply 82
When a voltage is applied between the primary electrodes 426 and 428 from
Piezoelectric ceramic substrate 30 between primary electrodes 426 and 428
0 is the vibration excited when a voltage is applied from the power supply 82 between the primary electrodes 322 and 324 and the primary electrode 42
Vibration is performed to further increase the vibration excited by the application of the voltage from the power supply 82 between 2, 424.

Therefore, the electric energy supplied from the power source 82 to the primary sides a and a 'can be more efficiently converted into mechanical elastic energy.

In the present embodiment, in addition to the primary electrodes 322, 324, 422, 424, the primary electrode 3
26, 328, 426, and 428 are further provided, so that the electrode areas on the primary sides a and a 'are increased, and the input impedance of the piezoelectric transformer is correspondingly reduced. As a result, electric energy is easily supplied to the piezoelectric transformer 100 from the power supply 82.

Further, by providing the primary electrodes 326 and 328, the region on the secondary side b is shortened in the longitudinal direction, and by providing the primary electrodes 426 and 428, the region on the secondary side b 'is shortened in the longitudinal direction. as a result,
The output impedance of the piezoelectric transformer 100 decreases. When the output impedance of the piezoelectric transformer 100 decreases, the secondary electrodes 374, 376 of the piezoelectric transformer 100
, The voltage applied to the CFL 90 connected thereto increases accordingly.

Therefore, according to the present embodiment, the electric energy supplied from the power supply 82 to the primary sides a and a ′ can be more efficiently converted into mechanical elastic energy. Is easily supplied, the output impedance of the piezoelectric transformer 100 is reduced, and the CFL 9
Since the voltage applied to 0 can be increased accordingly, the effective boosting ratio of the piezoelectric transformer can be increased.

Further, by providing the primary electrodes 326, 328, 426, and 428 as in this embodiment, the distance between the primary electrode and the secondary electrode is shortened. And secondary electrodes 374, 376
When the piezoelectric ceramic substrate 300 is polarized in the longitudinal direction, and between the primary electrodes 426, 428 and the secondary electrodes 374, 376.
Is polarized in the longitudinal direction, the absolute voltage of the high voltage applied at the time of polarization is smaller than in the case where these primary electrodes 326, 328, 426, 428 are not provided. As a result, a high-voltage countermeasure becomes easy, and a lower-voltage power supply can be used as the power supply for polarization.

In the present embodiment, the nodes 232, 234, and 236 of the vibration are set as the support points of the piezoelectric transformer 100, so that the inhibition of the vibration of the piezoelectric transformer 100 caused by supporting the piezoelectric transformer 100 is reduced. be able to.

Note that the method of manufacturing the piezoelectric transformer of the present embodiment is the same as that of the first embodiment.

(Twenty-Sixth Embodiment) FIG.
24A is a perspective view, FIG. 24B is a sectional view, FIG. 24C is a view showing a stress distribution, and FIG. 24D is a view showing an amplitude distribution.

As shown in FIGS. 24A and 24B, the left one-third of the upper surface 302 of the rectangular parallelepiped piezoelectric ceramic substrate 300 is formed.
Is provided with a primary electrode 322, and the primary electrode 322
A primary electrode 324 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 has an upper surface 3
It is polarized in the thickness direction between the bottom surface 02 and the lower surface 304.

The upper surface 302 of the piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 306 by a distance of 1/3 of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 306.
A primary electrode 326 is provided up to a position separated by a distance of 5/12 of the length in the longitudinal direction of 00, and a primary electrode 328 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 326. The primary electrode 326 is provided separately from the primary electrode 322, and the primary electrode 328 is provided separately from the primary electrode 324. The piezoelectric ceramic substrate 300 between the primary electrode 326 and the primary electrode 328 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

Top surface 302 of piezoelectric ceramic substrate 300
A primary electrode 422 is provided in a 1/3 region on the right side of
Piezoelectric ceramic substrate 300 facing primary electrode 422
A primary electrode 424 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300. The piezoelectric ceramic substrate 300 between the primary electrode 422 and the primary electrode 424 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

Top surface 302 of piezoelectric ceramic substrate 300
The piezoelectric ceramic substrate 3 is further separated from the primary end face 308 by a distance of 1/3 of the longitudinal length of the piezoelectric ceramic substrate 300 from the primary end face 308.
A primary electrode 426 is provided up to a position separated by a distance of 5/12 of the length in the longitudinal direction of 00, and a primary electrode 428 is also provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the primary electrode 426. The primary electrode 426 is provided separately from the primary electrode 422, and the primary electrode 428 is provided separately from the primary electrode 424. The piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428 is polarized in the thickness direction between the upper surface 302 and the lower surface 304.

The direction of polarization of the piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 and the primary electrode 4
Piezoelectric ceramic substrate 3 between first electrode 424 and first electrode 424
00 is the same as the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 326 and the primary electrode 328 and the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428. In Although,
The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 322 and the primary electrode 324 is opposite to the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 326 and the primary electrode 328, and the primary electrode 422 and the primary electrode 424
Is the direction opposite to the polarization direction of the piezoelectric ceramic substrate 300 between the primary electrode 426 and the primary electrode 428.

Top surface 302 of piezoelectric ceramic substrate 300
Further, a secondary electrode 374 is provided in the center of the piezoelectric ceramic substrate 300 in the longitudinal direction, and a secondary electrode 376 is provided on the lower surface 304 of the piezoelectric ceramic substrate 300 so as to face the secondary electrode 374. Primary electrodes 326, 3
The piezoelectric ceramic substrate 300 between the second electrode 28 and the secondary electrodes 374 and 376 is polarized in the longitudinal direction which is the direction in which the upper surface 302 and the lower surface 304 extend. Primary electrode 42
The piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 is polarized in the longitudinal direction which is the extending direction of the upper surface 302 and the lower surface 304. The polarization direction of the piezoelectric ceramic substrate 300 between the primary electrodes 326 and 328 and the secondary electrodes 374 and 376 and the primary electrode 42
The direction of polarization of the piezoelectric ceramic substrate 300 between 6, 428 and the secondary electrodes 374, 376 is opposite.

One end of the power supply 82 is connected to the primary electrode 322 via the connection portion 522, connected to the primary electrode 326 via the connection portion 526, and connected to the primary electrode 326 via the connection portion 626.
26, and the primary electrode 422 via the connection portion 622.
Is connected to The other end of the power supply 82 is connected to the primary electrode 324 via the connection 524, connected to the primary electrode 328 via the connection 528, connected to the primary electrode 428 via the connection 628, and connected via the connection 624. Connected to the primary electrode 424.

The secondary electrode 374 and the secondary electrode 376 are electrically connected, are both connected to one end of the CFL 90,
The other end of the CFL 90 is connected to the other end of the power supply 82.

Also in the present embodiment, the primary side end surface 30
Driving is performed in a resonance mode in which a stress distribution of 1.5 wavelength exists between 6 and the primary side end surface 308. A voltage having a frequency equal to the resonance frequency of the 1.5 wavelength mode is applied from the power supply 82. Both ends 30 of piezoelectric ceramic substrate 300
Since both 6 and 308 are open, the stress becomes zero at both ends in the longitudinal direction of the piezoelectric ceramic substrate 10 and the amplitude becomes maximum. In this embodiment, since resonance is performed in the 1.5-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 24C and 24D, respectively.

In the region where the primary electrodes 322 and 324 are provided, the stress, the polarization direction, the electric field direction and the primary electrodes 422 and 4
Since the stress, the polarization direction, and the electric field direction in the region where the first electrode 24 is provided are all the same, the vibration excited by the application of the voltage from the power source 82 between the primary electrodes 322 and 324 and the first electrode 422 and 424 Together with the vibration excited by the application of the voltage from the power supply 82 to the vibrations so as to further increase the mutual vibration.

The stress in the region where the primary electrodes 326 and 328 are provided is opposite to the stress in the region where the primary electrodes 322 and 324 are provided and the stress in the region where the primary electrodes 422 and 424 are provided. is there. Primary electrode 32
The polarization directions of the regions where the primary electrodes 322 and 324 are provided are opposite to the polarization directions of the regions where the primary electrodes 322 and 324 are provided and the regions where the primary electrodes 422 and 424 are provided. The direction of application of the electric field to the region where the primary electrodes 326 and 328 are provided
The direction is the same as the direction in which the electric field is applied to the area where the first and second electrodes 22 and 324 are provided and the direction in which the electric field is applied to the area where the primary electrodes 422 and 424 are provided. Therefore, the power supply 82
When a voltage is applied between the primary electrodes 326 and 328 from
Piezoelectric ceramic substrate 30 between primary electrodes 326 and 328
0 is the vibration excited when a voltage is applied from the power supply 82 between the primary electrodes 322 and 324 and the primary electrode 42
Vibration is performed to further increase the vibration excited by the application of the voltage from the power supply 82 between 2, 424.

The stress in the area where the primary electrodes 426 and 428 are provided is opposite to the stress in the area where the primary electrodes 322 and 324 are provided and the stress in the area where the primary electrodes 422 and 424 are provided. is there. Primary electrode 42
The polarization directions of the regions in which the primary electrodes 322 and 324 are provided and the polarization directions of the regions in which the primary electrodes 422 and 424 are provided are opposite to each other. The direction in which the electric field is applied to the region where the primary electrodes 426 and 428 are
The direction is the same as the direction in which the electric field is applied to the area where the first and second electrodes 22 and 324 are provided and the direction in which the electric field is applied to the area where the primary electrodes 422 and 424 are provided. Therefore, the power supply 82
When a voltage is applied between the primary electrodes 426 and 428 from
Piezoelectric ceramic substrate 30 between primary electrodes 426 and 428
0 is the vibration excited when a voltage is applied from the power supply 82 between the primary electrodes 322 and 324 and the primary electrode 42
Vibration is performed to further increase the vibration excited by the application of the voltage from the power supply 82 between 2, 424.

Therefore, the electric energy supplied from the power source 82 to the primary sides a and a 'can be more efficiently converted into mechanical elastic energy.

Also in the present embodiment, by providing the primary electrodes 326, 328, 426, and 428, the input impedance of the piezoelectric transformer 100 is reduced, so that electric energy is easily supplied from the power source 82 to the piezoelectric transformer 100. As in the twenty-fifth embodiment, the output impedance of the piezoelectric transformer 100 decreases and the voltage applied to the CFL 90 connected to the secondary electrodes 374 and 376 of the piezoelectric transformer 100 increases accordingly. As a result, the effective step-up ratio of the piezoelectric transformer can be increased as in the twenty-fifth embodiment.

Further, as described above, the primary electrodes 326 and 32
By providing 8, 426, and 428, the absolute voltage of the high voltage applied during polarization is reduced. As a result, it is easy to take measures against the high voltage, and the power supply for polarization can use a lower voltage power supply. Same as the form.

[0235] Also in this embodiment, the vibration nodes 232, 234, and 236 are used as the supporting points of the piezoelectric transformer 100, so that the inhibition of the vibration of the piezoelectric transformer 100 caused by supporting the piezoelectric transformer 100 is reduced. be able to.

The method of manufacturing the piezoelectric transformer according to the present embodiment is the same as that of the first embodiment.

(Twenty-Seventh Embodiment) FIG.
25A is a perspective view, FIG. 25B is a cross-sectional view, FIG. 25C is a view showing a stress distribution, and FIG. 25D is a view showing an amplitude distribution. .

As shown in FIGS. 25A and 25B, rectangular parallelepiped piezoelectric ceramic substrates 710 and 720 of the same size are laminated and integrated to form a piezoelectric ceramic laminated substrate 700. A primary electrode 732 is provided on the left (primary side) half of the upper surface 712 of the piezoelectric ceramic laminated substrate 700, and the piezoelectric ceramic laminated substrate 70 faces the primary electrode 732.
The primary electrode 734 is also provided on the lower surface 714 of the zero.

Top surface 7 of piezoelectric ceramic laminated substrate 700
12, the piezoelectric ceramic substrate 70 from the primary end face 716 is positioned at a distance from the primary end face 716 that is half the length of the piezoelectric ceramic laminated substrate 700 in the longitudinal direction.
Up to a distance of 3/4 of the longitudinal length of 0
A primary electrode 736 is provided, and a primary electrode 738 is also provided on the lower surface 714 of the piezoelectric ceramic laminated substrate 700 so as to face the primary electrode 736. The primary electrode 736 is provided separately from the primary electrode 732, and the primary electrode 738 is provided separately from the primary electrode 734.

At the center in the thickness direction of the piezoelectric ceramic laminated substrate 700, that is, at the boundary between the piezoelectric ceramic substrate 710 and the piezoelectric ceramic substrate 720, the longitudinal direction of the piezoelectric ceramic laminated substrate 700 from the primary end surface 716 to the primary end surface 716. The primary electrode 740 is provided in parallel with the primary electrodes 732 and 736 to a position separated by a distance of ３ of the length in the direction. The primary electrodes 732, 73
4, 736, 738, and 740 are provided to extend in the width direction from one width direction end surface 717 to the other width direction end surface 719 of the piezoelectric ceramic laminated substrate 700, respectively.

Between the primary electrode 732 and the primary electrode 740,
Between the primary electrode 736 and the primary electrode 740, the primary electrode 74
The piezoelectric ceramic laminated substrate 700 between 0 and the primary electrode 734 and between the primary electrode 740 and the primary electrode 738 is polarized in the thickness direction. The polarization direction between the primary electrode 732 and the primary electrode 740 is opposite to the polarization direction between the primary electrode 736 and the primary electrode 740, and is also opposite to the polarization direction between the primary electrode 740 and the primary electrode 734. And the direction of polarization between primary electrode 740 and primary electrode 738 is the same.

A secondary electrode 772 is provided on a secondary side end surface 718 perpendicular to the upper surface 712 and the lower surface 714, and the piezoelectric ceramic laminated substrate 700 between the primary electrodes 736, 740 and 738 and the secondary electrode 772 extends in the longitudinal direction. Is polarized at

One end of the power supply 82 is connected to the primary electrode 732 via the connection 832, connected to the primary electrode 736 via the connection 836, and connected to the primary electrode 736 via the connection 834.
34 and a primary electrode 738 via a connection 838.
Is connected to The other end of the power supply 82 is connected to the primary electrode 740 via the connection 840. Secondary electrode 772
Is connected to one end of CFL 90 as a load, and CFL 9
0 is connected to the other end of the power supply 82. The connecting portions 832 and 834 are provided at the node 202 of the vibration, and the connecting portions 832 and 834 are provided.
36 and 838 are provided in the vibration node 204.

As described above, in the multilayer piezoelectric transformer 1000 of the present embodiment, the two single-plate piezoelectric transformers 11
10 and 1120 are stacked back to back, and the corresponding primary electrodes are connected in parallel.

The multilayer piezoelectric transformer 100 of the present embodiment
At 0, driving is performed in a resonance mode in which a stress distribution of one wavelength exists between the primary end face 716 and the secondary end face 718.
From the power supply 82, a voltage having a frequency equal to the frequency of the resonance in the one-wavelength mode is applied. In the present embodiment, the support points are provided at a position separated to the right by a distance of 1/4 wavelength from the primary side end surface 716 and at a position separated to the left by 1/4 wavelength from the secondary side end surface 718. Primary end face 716 and secondary end face 718 of piezoelectric ceramic laminated substrate 700
Since both are open, the stress becomes zero at both ends in the longitudinal direction of the piezoelectric ceramic laminated substrate 700, and the amplitude becomes maximum. In the present embodiment, since resonance is performed in the one-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 25C and 25D, respectively.

The single-plate piezoelectric transformers 1110 and 1120 have the same functions and effects as those of the piezoelectric transformer 100 of the fourteenth embodiment, and as a result, the laminated piezoelectric transformer 1000 also has the piezoelectric transformer of the fourteenth embodiment. It has the same operation and effect as 100.

In addition, in the multi-layer piezoelectric transformer 1000 of the present embodiment, the input current flows twice as much as the single-plate piezoelectric transformers 1110 and 1120. Therefore, when the input power is constant, the input voltage is reduced by half. 1 and the input voltage can be reduced. Further, since the input current can flow twice, if the input voltage is kept constant, the input power can be doubled and high power driving can be performed. On the other hand, when the single-plate piezoelectric transformers 1110 and 1120 are used, if the energy density increases due to an increase in power, the loss increases above a threshold determined by the material, causing a decrease in efficiency. In order to avoid this, the above-described laminated structure can reduce the energy density in the piezoelectric ceramic and increase the total input power level.

Note that the plurality of piezoelectric transformers 1
By integrating the 110 and 1120, the vibration modes of the plurality of piezoelectric transformers 1110 and 1120 can be made uniform to form a single piezoelectric transformer.

Also, the laminated piezoelectric transformer 1000 of the present embodiment can be formed by bonding single-plate piezoelectric transformers 1110 and 1120, or by integrally sintering.

(Twenty-eighth Embodiment) FIG.
26A is a cross-sectional view, FIG. 26B is a diagram illustrating a stress distribution, and FIG. 26C is a diagram illustrating an amplitude distribution.

As shown in FIG. 26A, a rectangular parallelepiped piezoelectric ceramic substrate 730, 740, 750 of the same size is laminated and integrated to form a piezoelectric ceramic laminated substrate 700.

Top surface 7 of piezoelectric ceramic laminated substrate 700
A primary electrode 742 is provided on the left (primary side) half of 12, and is located at a distance of １ ／ in the thickness direction from the upper surface 712 of the piezoelectric ceramic laminated substrate 700, that is, between the piezoelectric ceramic substrate 730 and the piezoelectric ceramic substrate 740. At the boundary, a primary electrode 744 is provided in parallel with and opposite to the primary electrode 742, and the piezoelectric ceramic laminated substrate 700
A primary electrode 746 is provided parallel to and opposed to the primary electrode 742 at a distance of ２ of the thickness direction from the upper surface 712 of the piezoelectric ceramic substrate, that is, at the boundary between the piezoelectric ceramic substrate 740 and the piezoelectric ceramic substrate 750. A primary electrode 748 is also provided on the lower surface 714 of the ceramic multilayer substrate 700 in parallel with and opposed to the primary electrode 742.

Upper surface 7 of piezoelectric ceramic laminated substrate 700
12, the piezoelectric ceramic substrate 70 from the primary end face 716 is positioned at a distance from the primary end face 716 that is half the length of the piezoelectric ceramic laminated substrate 700 in the longitudinal direction.
Up to a distance of 3/4 of the longitudinal length of 0
A primary electrode 754 is provided at a distance of １ ／ in the thickness direction from the upper surface 712 of the piezoelectric ceramic laminated substrate 700, that is, at the boundary between the piezoelectric ceramic substrate 730 and the piezoelectric ceramic substrate 740. 752 is provided in parallel with and opposed to the upper surface 712 of the piezoelectric ceramic laminated substrate 700 in the thickness direction.
At a distance of / 3, that is, at the boundary between the piezoelectric ceramic substrate 740 and the piezoelectric ceramic substrate 750, a primary electrode 756 is provided in parallel with and opposed to the primary electrode 752, and the lower surface 714 of the piezoelectric ceramic multilayer substrate 700
Also, a primary electrode 758 is provided in parallel with and opposed to the primary electrode 752. The primary electrode 752 is the primary electrode 742
And the primary electrode 754 is separated from the primary electrode 744.
And the primary electrode 756 is separated from the primary electrode 746.
And the primary electrode 758 is separated from the primary electrode 748.
And are provided separately.

The primary electrodes 742, 744, 74
6, 748, 752, 754, 756, and 758 extend in the width direction from one width direction end face to the other width direction end face of the piezoelectric ceramic laminated substrate 700, respectively, as in the twenty-seventh embodiment. Is provided.

Between the primary electrode 742 and the primary electrode 744,
Between the primary electrode 744 and the primary electrode 746, the primary electrode 74
6 and the primary electrode 748, between the primary electrode 752 and the primary electrode 754, between the primary electrode 754 and the primary electrode 756, and between the primary electrode 756 and the primary electrode 758. Is polarized at The polarization direction between primary electrode 742 and primary electrode 744 is opposite to the polarization direction between primary electrode 744 and primary electrode 746 and is the same as the polarization direction between primary electrode 746 and primary electrode 748. , The direction of polarization between the primary electrode 752 and the primary electrode 754 is opposite to that of the primary electrode 752.
4 is the same as the polarization direction between primary electrode 756 and opposite to the polarization direction between primary electrode 756 and primary electrode 758.

A secondary electrode 772 is provided on a secondary end surface 718 perpendicular to the upper surface 712 and the lower surface 714, and the primary electrodes 752, 754, 756 and 758 and the secondary electrode 772 are provided.
The piezoelectric ceramic laminated substrate 700 is polarized in the longitudinal direction.

One end of the power supply 82 is connected to the primary electrode 742 via the connection portion 842, connected to the primary electrode 752 via the connection portion 852, and connected to the primary electrode 7 via the connection portion 846.
46 and the primary electrode 756 via the connection portion 856.
Is connected to The other end of the power supply 82 is connected to the primary electrode 744 via the connection portion 844, connected to the primary electrode 754 via the connection portion 854, connected to the primary electrode 748 via the connection portion 848, and connected via the connection portion 858. Connected to the primary electrode 758. The secondary electrode 772 is connected to one end of the CFL 90 as a load, and the other end of the CFL 90 is connected to the other end of the power supply 82. In addition, the connection part 842,
844, 846, and 848 are provided at the vibration node 202, and the connection portions 852, 854, 856, and 858 are provided at the vibration node 204.

As described above, in the laminated piezoelectric transformer 1000 of the present embodiment, the single-plate piezoelectric transformers 1130 and 1140 are stacked back to back, and the single-plate piezoelectric transformers 1140 and 1150 are stacked back to back. And
The corresponding primary electrodes are connected in parallel.

The multilayer piezoelectric transformer 100 of the present embodiment
At 0, driving is performed in a resonance mode in which a stress distribution of one wavelength exists between the primary end face 716 and the secondary end face 718.
From the power supply 82, a voltage having a frequency equal to the frequency of the resonance in the one-wavelength mode is applied. In the present embodiment, the support points are provided at a position separated to the right by a distance of 1/4 wavelength from the primary side end surface 716 and at a position separated to the left by 1/4 wavelength from the secondary side end surface 718. Primary end face 716 and secondary end face 718 of piezoelectric ceramic laminated substrate 700
Since both are open, the stress becomes zero at both ends in the longitudinal direction of the piezoelectric ceramic laminated substrate 700, and the amplitude becomes maximum. In the present embodiment, since resonance is performed in the one-wavelength mode, the stress distribution and the amplitude distribution are as shown in FIGS. 26B and 26C, respectively.

A single-plate piezoelectric transformer 1130, 1140,
1150 show the same operation and effect as the piezoelectric transformer 100 of the fourteenth embodiment. As a result, the multilayer piezoelectric transformer 1000 also has the same operation and effect as the piezoelectric transformer 100 of the fourteenth embodiment. ing.

In addition, in the multi-layer piezoelectric transformer 1000 of the present embodiment, the input current flows three times that of the single-plate piezoelectric transformers 1130, 1140, and 1150. Therefore, when the input power is constant, the input voltage becomes three. That is, the input voltage can be reduced. Further, since the input current can flow three times, if the input voltage is kept constant, the input power can be increased three times and high-power driving can be performed. In contrast, single-plate piezoelectric transformers 1130 and 11
In the case where 40, 1150 is used, if the energy density increases due to an increase in power, the loss increases above a threshold determined by the material, causing a decrease in efficiency. In order to avoid this, the above-described laminated structure can reduce the energy density in the piezoelectric ceramic and increase the total input power level.

Note that the plurality of piezoelectric transformers 1
By integrating 130, 1140, 1150, a plurality of piezoelectric transformers 1130, 1140, 1150
And the vibration modes can be made uniform.

Also, the laminated piezoelectric transformer 1000 of the present embodiment has a single-plate piezoelectric transformer 1130, 1140,
1150 may be formed by bonding or may be formed by sintering.

[0264]

According to the piezoelectric transformer of the present invention, a large boost ratio can be obtained. The piezoelectric transformer of the present invention is C
It can be suitably used as a step-up transformer for FL lighting, in which case the input voltage can be reduced.

Also, since the polarization on the secondary side can be performed with a smaller absolute voltage, it is easy to take measures against high voltage, a power supply for polarization can be used at a lower voltage, and the equipment for polarization can be simplified. .

Further, not only the step-up ratio of the piezoelectric transformer but also the output impedance can be easily adjusted, so that the degree of freedom in design is improved.

[Brief description of the drawings]

FIGS. 1A and 1B are views for explaining a piezoelectric transformer according to a first embodiment of the present invention. FIG. 1A is a perspective view, FIG. 1B is a cross-sectional view, FIG. 1C shows a stress distribution, and FIG. It is a figure showing distribution.

FIG. 2 is a diagram illustrating a relationship between an input voltage to a piezoelectric transformer and luminance of a cold cathode tube according to the first embodiment of the present invention.

FIG. 3 is a view for explaining piezoelectric transformers according to second to fourth embodiments of the present invention. FIG.
FIG. 3B is a sectional view of a piezoelectric transformer according to a third embodiment of the present invention, and FIG. 3C is a sectional view of a piezoelectric transformer according to a fourth embodiment of the present invention. 3D is a cross-sectional view, FIG. 3D is a diagram showing a stress distribution of the piezoelectric transformer shown in FIGS. 3A to 3C, and FIG. 3E is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIGS. 3A to 3C.

4A and 4B are views for explaining a piezoelectric transformer according to a fifth embodiment of the present invention, wherein FIG. 4A is a sectional view, FIG. 4B is a view showing a stress distribution, and FIG. 4C is a view showing an amplitude distribution. .

5A and 5B are views for explaining a piezoelectric transformer according to a sixth embodiment of the present invention, wherein FIG. 5A is a perspective view, FIG. 5B is a cross-sectional view, FIG. 5C shows a stress distribution, and FIG. It is a figure showing distribution.

FIG. 6 is a diagram for explaining piezoelectric transformers according to seventh and eighth embodiments of the present invention. FIG. 6A is a cross-sectional view of the piezoelectric transformer according to the seventh embodiment of the present invention. 6B
FIG. 6C is a cross-sectional view of a piezoelectric transformer according to an eighth embodiment of the present invention, FIG. 6C is a diagram showing a stress distribution of the piezoelectric transformer shown in FIGS. 6A and 6B, and FIG. FIG. 4 is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIG.

FIG. 7 is a perspective view of a piezoelectric transformer according to a ninth embodiment of the present invention.

FIG. 8 is a perspective view of a piezoelectric transformer according to a tenth embodiment of the present invention.

9A and 9B are views for explaining a piezoelectric transformer and a method of driving the same according to an eleventh embodiment of the present invention. FIG. 9A is a perspective view, FIG. 9B is a view showing a stress distribution, and FIG. FIG.

FIG. 10 is a diagram for explaining a piezoelectric transformer and a driving method thereof according to a twelfth embodiment of the present invention.
10A is a perspective view, FIG. 10B is a diagram showing a stress distribution, and FIG. 10C is a diagram showing an amplitude distribution.

FIG. 11 is a diagram for explaining a piezoelectric transformer according to a thirteenth embodiment of the present invention. FIG. 11A is a perspective view, FIG.
B is a sectional view, FIG. 11C is a diagram showing a stress distribution, and FIG. 11D is a diagram showing an amplitude distribution.

FIG. 12 is a diagram for explaining a piezoelectric transformer according to a fourteenth embodiment of the present invention. FIG. 12A is a perspective view, and FIG.
B is a sectional view, FIG. 12C is a diagram showing a stress distribution, and FIG. 12D is a diagram showing an amplitude distribution.

FIG. 13 is a diagram illustrating a relationship between an input voltage to a piezoelectric transformer and luminance of a cold cathode tube according to a fourteenth embodiment of the present invention.

FIG. 14 is a perspective view for explaining a method for manufacturing a piezoelectric transformer according to a fourteenth embodiment of the present invention.

FIG. 15 is a diagram for explaining piezoelectric transformers according to fifteenth and sixteenth embodiments of the present invention. FIG. 15A is a sectional view of the piezoelectric transformer according to the fifteenth embodiment of the present invention. 15B is a sectional view of a piezoelectric transformer according to a sixteenth embodiment of the present invention, and FIG. 15C is a sectional view of FIGS.
FIG. 1B is a diagram showing a stress distribution of the piezoelectric transformer shown in FIG.
FIG. 5D is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIGS. 15A and 15B.

16A and 16B are views for explaining a piezoelectric transformer according to a seventeenth embodiment of the present invention. FIG. 16A is a perspective view, FIG.
B is a sectional view, FIG. 16C is a diagram showing a stress distribution, and FIG. 16D is a diagram showing an amplitude distribution.

FIG. 17 is a view for explaining piezoelectric transformers according to eighteenth and nineteenth embodiments of the present invention. FIG. 17A is a sectional view of the piezoelectric transformer according to the eighteenth embodiment of the present invention. FIG. 17B is a sectional view of a piezoelectric transformer according to a nineteenth embodiment of the present invention, and FIG. 17C is a sectional view of FIGS.
FIG. 1B is a diagram showing a stress distribution of the piezoelectric transformer shown in FIG.
FIG. 7D is a diagram showing an amplitude distribution of the piezoelectric transformer shown in FIGS. 17A and 17B.

FIG. 18 is a perspective view of a piezoelectric transformer according to a twentieth embodiment of the present invention.

FIG. 19 is a perspective view of a piezoelectric transformer according to a twenty-first embodiment of the present invention.

FIG. 20 is a diagram for explaining a piezoelectric transformer and a driving method thereof according to a twenty-second embodiment of the present invention.
A is a perspective view, FIG. 20B is a diagram showing a stress distribution, and FIG. 20C is a diagram showing an amplitude distribution.

FIG. 21 is a diagram for explaining a piezoelectric transformer and a driving method thereof according to a twenty-third embodiment of the present invention.
21A is a perspective view, FIG. 21B is a diagram showing a stress distribution, and FIG. 21C is a diagram showing an amplitude distribution.

FIG. 22 is a diagram for explaining a piezoelectric transformer according to a twenty-fourth embodiment of the present invention. FIG. 22A is a perspective view, and FIG.
B is a cross-sectional view, FIG. 22C is a diagram showing a stress distribution, and FIG. 22D is a diagram showing an amplitude distribution.

FIG. 23 is a diagram for explaining a piezoelectric transformer according to a twenty-fifth embodiment of the present invention. FIG. 23A is a perspective view, and FIG.
B is a sectional view, FIG. 23C is a diagram showing a stress distribution, and FIG. 23D is a diagram showing an amplitude distribution.

24A and 24B are views for explaining a piezoelectric transformer according to a twenty-sixth embodiment of the present invention. FIG. 24A is a perspective view, FIG.
24B is a sectional view, FIG. 24C is a diagram showing a stress distribution, and FIG. 24D is a diagram showing an amplitude distribution.

FIG. 25 is a view for explaining a piezoelectric transformer according to a twenty-seventh embodiment of the present invention. FIG. 25A is a perspective view, FIG.
B is a cross-sectional view, FIG. 25C is a diagram showing a stress distribution, and FIG. 25D is a diagram showing an amplitude distribution.

FIG. 26 is a view for explaining a piezoelectric transformer according to a twenty-eighth embodiment of the present invention. FIG. 26A is a sectional view, and FIG.
B is a diagram showing a stress distribution, and FIG. 26C is a diagram showing an amplitude distribution.

27A and 27B are views for explaining a conventional piezoelectric transformer, FIG. 27A is a perspective view, FIG. 27B is a cross-sectional view, FIG. 27C is a view showing a stress distribution, and FIG. 27D is a view showing an amplitude distribution.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Piezoelectric ceramic substrate 12 ... Upper surface 14 ... Lower surface 16 ... Primary side end surface 18 ... Secondary side end surface 22, 24, 26, 28, 32, 34, 36, 38, 4
2, 44, 52, 54, 56, 58, 62, 64 ... primary electrodes 23, 27 ... return electrodes 53, 55 ... return electrodes 72, 74, 76 ... secondary electrodes 82 ... power supply 84 ... amplifier circuit 86 ... phase shift Circuit 90: cold cathode fluorescent lamp (CFL) 100: piezoelectric transformer 122, 124, 126, 128, 132, 134, 1
36, 138, 142, 144, 152, 154, 15
6, 158, 162, 164: Connections 123, 127 ... Connections 153, 155 ... Connections 174 ... Connections 202, 204, 212, 214, 216, 222, 2
24, 226, 228, 232, 234, 236: nodes of vibration 300: piezoelectric ceramic substrate 302: upper surface 304: lower surface 306, 308: primary side end surfaces 322, 324, 326, 328, 352, 354, 4
22, 424, 426, 428, 452, 454 ... primary electrodes 374, 376 ... secondary electrodes 522, 524, 526, 528, 552, 554, 6
22, 624, 626, 628, 652, 654... Connections 521, 523, 541, 543... Polarizing electrodes 700... Piezoelectric ceramic laminated substrates 710, 720, 730, 740, 750. 716: Primary end face 718: Secondary end face 717, 719: Width end face 732, 734, 736, 738, 740, 742, 7
44, 746, 748, 752, 754, 756, 75
8 Primary electrode 772 Secondary electrode 832, 834, 836, 838, 840, 842, 8
44, 846, 848, 852, 854, 856, 85
8. Connection part 1000 Multilayer piezoelectric transformer 1110, 1120, 1130, 1140, 1150
Single-plate piezoelectric transformer

Continuation of the front page (56) References JP-A-7-302938 (JP, A) JP-A-7-193293 (JP, A) JP-A-6-338641 (JP, A) Japanese Utility Model Application Sho 63-201362 (JP) , U) Shokai 55-71573 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 41/107 H01L 41/22

Claims (35)

(57) [Claims] A piezoelectric substrate having a first main surface and a second main surface facing the first main surface, wherein the first main surface and the second main surface extend. A piezoelectric transformer using a longitudinal vibration resonance mode in a longitudinal direction of the piezoelectric substrate, wherein the resonance mode is a resonance mode in which a stress distribution of at least one wavelength or more exists in the longitudinal direction, and the resonance in the longitudinal direction. approximately <br/> wherein a first region of the piezoelectric substrate where the positive or negative of any one of the stresses occurring in the longitudinal direction when the resonance has a length of half of the wavelength of the stress distribution when The longitudinal direction of the piezoelectric substrate
A first primary electrode and a second primary electrode are respectively provided on the first main surface and the second main surface of the first region at a position including an end of the first region so as to face each other; In the region between the first primary electrode and the second primary electrode is polarized in the thickness direction between the first main surface and the second main surface, and the first region is in the longitudinal direction. A piezoelectric transformer in which a secondary electrode is provided in a second region of the piezoelectric substrate that is separated by a predetermined distance, wherein a third region adjacent to the first region of the piezoelectric substrate is provided.
There are, the stress opposite the stress of the longitudinal direction in the said longitudinal direction in the positive or negative of the first region to the stress the time of resonance has a half wavelength or less of the length of the distribution at the time of resonance occurs A third region, wherein a third primary electrode and a fourth primary electrode are respectively provided on the first main surface and the second main surface of the third region so as to face each other; Responsive to the direction of the stress generated in the third region during the resonance, such that the third region vibrates to further increase the resonance excited by the first and second primary electrodes and the first region. The space between the third primary electrode and the fourth primary electrode in the third region is polarized in a predetermined direction in the thickness direction, and the third primary electrode and the fourth primary electrode are The first primary electrode and the second primary electrode The electrodes are electrically connected in a predetermined connection state, and the piezoelectric ceramic substrate between the end of the third primary electrode and the fourth primary electrode on the secondary electrode side and the secondary electrode is A piezoelectric transformer, wherein the piezoelectric transformer is polarized in the longitudinal direction. 2. The polarization direction between the third primary electrode and the fourth primary electrode in the third region is set between the first primary electrode and the second primary electrode in the first region. The third primary electrode and the second primary electrode are electrically connected, and the fourth primary electrode and the first primary electrode are electrically connected. The piezoelectric transformer according to claim 1, wherein: 3. The polarization direction between the third primary electrode and the fourth primary electrode in the third region is equal to the polarization direction between the first primary electrode and the second primary electrode in the first region. The third primary electrode and the first primary electrode are electrically connected, and the fourth primary electrode and the second primary electrode are electrically connected. The piezoelectric transformer according to claim 1, wherein: 4. The piezoelectric substrate according to claim 3, wherein the third region and the second region of the piezoelectric substrate are connected to each other.
The stress at the time of the resonance in the longitudinal direction between
Having a length equal to or less than half a wavelength of the distribution,
The stress in the same direction as the direction of the stress generated in the region is
Further comprising a fourth region generated at the time of shaking, The first main surface and the second main surface of the fourth region
The fifth primary electrode and the sixth primary electrode
Is provided facing the The fifth primary electrode and the sixth primary in the fourth region
The direction of polarization between the electrodes is the first primary of the first region.
The same as the polarization direction between the electrode and the second primary electrode, The fifth primary electrode and the first primary electrode are electrically connected;
The sixth primary electrode and the second primary electrode
The electrodes are electrically connected, The second one of the fifth primary electrode and the sixth primary electrode
The piezoelectric ceramic between the end on the side of the next electrode and the secondary electrode
The substrate is polarized in the longitudinal direction.
4. The piezoelectric transformer according to claim 2, wherein: 5. The method according to claim 1, wherein said resonance mode is less in said longitudinal direction.
Both are in resonance mode where stress distribution of 1.5 wavelength or more exists
Yes, Almost the stress distribution at the time of the resonance in the longitudinal direction
Having a length of half a wavelength in the longitudinal direction at the time of the resonance
The piezoelectric element in which either positive or negative stress occurs.
A fifth region of the substrate, wherein the second region is the first region
And the second region so as to be sandwiched between the second region and the fifth region.
Further comprising an area on the opposite side to the first area, The first main surface and the second main surface of the fifth region are
7 and the eighth primary electrode are respectively opposed to each other.
Provided facing The first and second primary electrodes and the first region
To further increase the resonance excited by
At the time of the resonance, the fifth region is vibrated so that the fifth region vibrates.
Depending on the direction of the stress generated in the region,
The distance between the seventh primary electrode and the eighth primary electrode is in the thickness direction.
Is polarized in a predetermined direction and
A primary electrode, the eighth primary electrode, and the first primary electrode;
The electrode and the second primary electrode are electrically connected to a predetermined connection state.
Connected The longitudinal direction between the fifth region and the second region;
A length less than half a wavelength of the stress distribution at the time of the resonance.
At the time of the resonance, either positive or negative in the longitudinal direction
Sixth region of the piezoelectric substrate where any one stress occurs
And the first main surface of the sixth region and
A ninth primary electrode and a tenth primary electrode are provided on the second main surface.
The poles are provided opposite each other, The first and second primary electrodes and the first region
To further increase the resonance excited by
At the time of the resonance, the sixth region is vibrated so that the region 6 vibrates.
According to the direction of the stress generated in the region, the sixth region
The distance between the ninth primary electrode and the tenth primary electrode is the thickness
Polarized in a predetermined direction With the ninth
Primary electrode and the tenth primary electrode and the first primary electrode.
The secondary electrode and the second primary electrode in a predetermined connection state
Electrically connected, The secondary electrodes of the ninth electrode and the tenth electrode
The piezoelectric ceramic between the side end and the secondary electrode
Wherein the substrate is polarized in the longitudinal direction.
The piezoelectric transformer according to claim 1, wherein 6. The second region, the third region and a front region.
The sixth region is a region in which pressure is applied in the longitudinal direction during the resonance.
The same half where only shrinkage or tension stress occurs
Coexist in the wavelength region, and its stress direction corresponds to the first region.
6. The piezoelectric device according to claim 5, wherein the direction is opposite to the force direction.
Trance. 7. A stress generated in the fifth region at the time of the resonance.
Is the direction of the stress generated in the first region at the time of the resonance.
Opposite to the direction The direction of the stress generated in the sixth region at the time of the resonance is
The same as the direction of the stress generated in the first region at the time of resonance.
6. The piezoelectric transformer according to claim 5, wherein: 8. A first main surface, a second main surface facing the first main surface, and orthogonal to a longitudinal direction in which the first main surface and the second main surface extend. A piezoelectric transformer having a piezoelectric substrate having a first end surface and a second end surface, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, Two primary electrodes are formed on the first main surface and the second main surface of the piezoelectric substrate, and are １ ／ of a distance between the first end surface and the second end surface from the first end surface. to the position of the length distance provided extending respectively in the longitudinal direction, the first and second primary electrode and the first main of a predetermined area of said piezoelectric substrate between said secondary electrode A third and a fourth primary electrode are spaced apart from the secondary electrode on a surface and the second main surface, respectively. The piezoelectric ceramic substrate between the secondary electrode and the end of the third primary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction; The piezoelectric substrate between the first primary electrode and the second primary electrode is polarized in a thickness direction between the first main surface and the second main surface, and the third primary electrode and the fourth primary electrode are polarized. The piezoelectric substrate between the electrodes is polarized in the thickness direction in the same direction as the polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode, and the fourth primary electrode and the fourth A piezoelectric transformer, wherein one primary electrode is electrically connected, and the third primary electrode and the second primary electrode are electrically connected. 9. A first main surface, a second main surface facing the first main surface, and orthogonal to a longitudinal direction in which the first main surface and the second main surface extend. A piezoelectric transformer having a piezoelectric substrate having a first end surface and a second end surface, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, Two primary electrodes are formed on the first main surface and the second main surface of the piezoelectric substrate, and are １ ／ of a distance between the first end surface and the second end surface from the first end surface. to the position of the length distance provided extending respectively in the longitudinal direction, the first and second primary electrode and the first main of a predetermined area of said piezoelectric substrate between said secondary electrode A third and a fourth primary electrode are spaced apart from the secondary electrode on a surface and the second main surface, respectively. The piezoelectric ceramic substrate between the secondary electrode and the end of the third primary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction; The piezoelectric substrate between the first primary electrode and the second primary electrode is polarized in a thickness direction between the first main surface and the second main surface, and the third primary electrode and the fourth primary electrode are polarized. The piezoelectric substrate between the electrodes is polarized in the thickness direction in a direction opposite to a polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode, and the third primary electrode and the third A piezoelectric transformer, wherein one primary electrode is electrically connected, and the fourth primary electrode and the second primary electrode are electrically connected. 10. A first main surface, a second main surface facing the first main surface, and orthogonal to a longitudinal direction in which the first main surface and the second main surface extend. A piezoelectric transformer having a piezoelectric substrate having a first end surface and a second end surface, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, Two primary electrodes are formed on the first main surface and the second main surface of the piezoelectric substrate on the first main surface and one third of a distance between the first end surface and the second end surface from the first end surface. And a third and a fourth primary electrode are provided on the first main surface and the second main surface of the piezoelectric substrate. or the position of the length distance of 1/3 of the distance between the first said from the end face a first end surface and the second end face , 2 from the first end surface of the distance between the second end surface and the first end surface
A third of the third primary electrode and the fourth primary electrode, the third primary electrode and the second primary electrode being provided so as to extend from the secondary electrode to a position having a length of / 3 of the length. The piezoelectric ceramic substrate between the end of the first side and the secondary electrode is polarized in the longitudinal direction, and the piezoelectric substrate between the first primary electrode and the second primary electrode is the first substrate. The piezoelectric substrate between the third primary electrode and the fourth primary electrode is polarized in a thickness direction between the main surface and the second main surface, and the first primary electrode and the second Are polarized in the same direction as the polarization direction of the piezoelectric substrate between the primary electrodes, the fourth primary electrode and the first primary electrode are electrically connected, and the third primary electrode and the second That the primary electrodes are electrically connected Characteristic piezoelectric transformer. 11. A first main surface, a second main surface facing the first main surface, and orthogonal to a longitudinal direction in which the first main surface and the second main surface extend. A piezoelectric transformer having a piezoelectric substrate having a first end surface and a second end surface, wherein a secondary electrode is provided on the piezoelectric substrate at a predetermined position in the longitudinal direction of the piezoelectric substrate, Two primary electrodes are formed on the first main surface and the second main surface of the piezoelectric substrate on the first main surface and one third of a distance between the first end surface and the second end surface from the first end surface. And a third and a fourth primary electrode are provided on the first main surface and the second main surface of the piezoelectric substrate. the first third of <br/> length of the tens distance distance between the end surface and the first end surface and the second end face From the from the first end to the 2/3 position of the length distance of the distance between the second end surface and the first end surface, spaced from the secondary electrode, in the longitudinal direction The piezoelectric ceramic substrate between the secondary electrode and the end of the third primary electrode and the fourth primary electrode on the secondary electrode side is polarized in the longitudinal direction. The piezoelectric substrate between the first primary electrode and the second primary electrode is polarized in a thickness direction between the first main surface and the second main surface, and the third primary electrode The piezoelectric substrate between the fourth primary electrodes is polarized in the thickness direction in a direction opposite to the polarization direction of the piezoelectric substrate between the first primary electrode and the second primary electrode; A primary electrode and the first primary electrode are electrically connected; Serial piezoelectric transformer is the fourth primary electrode and the second primary electrode, characterized in that it is electrically connected. 12. The third and fourth primary electrodes and the second electrode.
A first region of the piezoelectric substrate between a first electrode and a next electrode;
On the surface and the second main surface, spaced apart from the secondary electrode.
And fifth and sixth primary electrodes are further provided.
And The piezoelectric element between the fifth primary electrode and the sixth primary electrode
The substrate has the first primary electrode and the first electrode in the thickness direction.
The same direction as the polarization direction of the piezoelectric substrate between the second primary electrodes
Polarized to The fifth primary electrode and the first primary electrode are electrically connected;
The sixth primary electrode and the second primary electrode
The electrodes are electrically connected, The second one of the fifth primary electrode and the sixth primary electrode
The piezoelectric ceramic between the end on the side of the next electrode and the secondary electrode
The substrate is polarized in the longitudinal direction.
The piezoelectric transformer according to claim 10 or 11, wherein
Su. 13. A piezoelectric substrate having a first main surface and a second main surface facing the first main surface, wherein the first main surface and the second main surface extend. One direction is defined as a longitudinal direction of the piezoelectric substrate, and the piezoelectric substrate has at least a first region, a second region, and a third region that divide the longitudinal direction, and the first region of the piezoelectric substrate Has a length of 1 / n (n is an integer of 2 or more) of the longitudinal length of the piezoelectric substrate at a position including the longitudinal end of the piezoelectric substrate, and A first primary electrode and a second primary electrode are respectively provided on the first main surface and the second main surface of the first region so as to face each other, and the first primary electrode of the first region is provided. And the second primary electrode are polarized in the thickness direction between the first main surface and the second main surface; The region above the longitudinal direction in the second region of said piezoelectric substrate spaced predetermined intervals secondary electrode is provided, said third region is provided adjacent the said first region,
A third primary electrode having a length equal to or less than 1 / n of a length in the longitudinal direction of the piezoelectric substrate; and a third primary electrode and a fourth primary electrode provided on the first main surface and the second main surface of the third region. Primary electrodes are provided so as to face each other, the third primary electrode and the fourth primary electrode in the third region are polarized in the thickness direction, and the third primary electrode and the fourth The polarization direction of the third region between the primary electrodes is the same as the polarization direction of the first region between the first primary electrode and the second primary electrode; A second primary electrode is electrically connected, the fourth primary electrode is electrically connected to the first primary electrode, and the second region is polarized in the longitudinal direction. Piezo transformer. 14. A piezoelectric substrate having a first main surface and a second main surface facing the first main surface, wherein the first main surface and the second main surface extend. One direction is defined as a longitudinal direction of the piezoelectric substrate, and the piezoelectric substrate has at least a first region, a second region, and a third region that divide the longitudinal direction, and the first region of the piezoelectric substrate Has a length of 1 / n (n is an integer of 2 or more) of the longitudinal length of the piezoelectric substrate at a position including the longitudinal end of the piezoelectric substrate, and A first primary electrode and a second primary electrode are respectively provided on the first main surface and the second main surface of the first region so as to face each other, and the first primary electrode of the first region is provided. And the second primary electrode are polarized in the thickness direction between the first main surface and the second main surface; The region above the longitudinal direction in the second region of said piezoelectric substrate spaced predetermined intervals secondary electrode is provided, said third region is provided adjacent the said first region,
A third primary electrode having a length equal to or less than 1 / n of a length in the longitudinal direction of the piezoelectric substrate; and a third primary electrode and a fourth primary electrode provided on the first main surface and the second main surface of the third region. Primary electrodes are provided so as to face each other, the third primary electrode and the fourth primary electrode in the third region are polarized in the thickness direction, and the third primary electrode and the fourth The direction of polarization of the third region between the primary electrodes is opposite to the direction of polarization of the first region between the first primary electrode and the second primary electrode; A first primary electrode is electrically connected, the fourth primary electrode is electrically connected to the second primary electrode, and the second region is polarized in the longitudinal direction. Piezo transformer. 15. The piezoelectric substrate further includes a fifth region and a sixth region dividing the longitudinal direction, wherein the fifth region is different from the second region in the first region and the sixth region. provided on the opposite side, the said longitudinal length 1
/ N , wherein a seventh primary electrode and an eighth primary electrode are provided on the first main surface and the second main surface of the fifth region, respectively, so as to face each other. A stress generated in the fifth region at the time of the resonance so that the fifth region vibrates to further increase the resonance of the piezoelectric substrate excited by the first and second primary electrodes and the first region; Between the seventh primary electrode and the eighth primary electrode in the fifth region is polarized in the thickness direction in accordance with the direction of the fifth region.
The first primary electrode and the eighth primary electrode are electrically connected to the first primary electrode and the second primary electrode in a predetermined connection state, and the sixth region is connected to the fifth region and the fifth region. The first main surface and the second main surface of the sixth region are provided between the first region and the second region, and have a length equal to or less than 1 / n of the length in the longitudinal direction. A ninth primary electrode and a tenth primary electrode are provided to face each other, and further increase the resonance of the piezoelectric substrate excited by the first and second primary electrodes and the first region. In order to vibrate the sixth region, the distance between the ninth primary electrode and the tenth primary electrode in the sixth region depends on the direction of the stress generated in the sixth region during the resonance. The ninth primary power polarized in the thickness direction. And the tenth primary electrode is electrically connected to the first primary electrode and the second primary electrode in a predetermined connection state, and the secondary electrode is connected to at least the first or second main surface. The piezoelectric transformer according to claim 13, wherein the second region on either side of the secondary electrode is polarized in the longitudinal direction. 16. The piezoelectric device according to claim 16, wherein the secondary electrode is formed in the longitudinal direction of the piezoelectric substrate.
Characterized in that it is formed on the end face perpendicular to the direction
Any one of claims 1 to 4 and claims 8 to 14
Onboard piezoelectric transformer. 17. The method according to claim 17, wherein the secondary electrode is provided on the first side of the piezoelectric substrate.
At least one of the principal surface and the second principal surface of
The method according to any one of claims 1 to 14, wherein
A piezoelectric transformer according to any one of the claims. 18. The pressure according to claim 1, wherein:
A plurality of electric transformers are stacked and integrated in the thickness direction,
The primary side of the electric transformer is the primary side of another piezoelectric transformer.
The area is stacked and the secondary area of each piezoelectric transformer is
The secondary side region of the piezoelectric transformer is laminated, and the plurality of piezoelectric
The direction of polarization of the primary region of the transformer and the
The connection state of the poles causes the plurality of piezoelectric transformers to vibrate each other.
Laminate characterized by being set to further increase
Type piezoelectric transformer. 19. A part of said primary electrode is referred to as said primary electrode.
Characterized by a feedback electrode provided electrically insulated
The piezoelectric transformer according to any one of claims 1 to 18,
Su. 20. A phase shift circuit and an amplifier circuit for the feedback electrode.
And apply the output of the amplifier circuit to the primary electrode.
20. The drive of the piezoelectric transformer according to claim 19, wherein
Motion circuit. 21. A piezoelectric transformer for lighting a cold-cathode tube.
21. The transformer according to claim 1, wherein the transformer is a transformer.
The piezoelectric transformer described in any of the above. 22. A piezoelectric transformer according to claim 1 incorporated therein.
An inverter characterized by that. 23. A piezoelectric transformer according to claim 8 is incorporated.
An inverter characterized by that. 24. A piezoelectric transformer according to claim 9 is incorporated.
An inverter characterized by that. 25. A piezoelectric transformer according to claim 10 is incorporated.
Inverter. 26. The piezoelectric transformer according to claim 11, which is incorporated.
Inverter. 27. A piezoelectric transformer according to claim 13 is incorporated.
Inverter. 28. The piezoelectric transformer according to claim 14, which is incorporated.
Inverter. 29. A piezoelectric transformer according to claim 1 incorporated therein.
Liquid crystal display characterized by the following. 30. A piezoelectric transformer according to claim 8 is incorporated.
Liquid crystal display characterized by the following. 31. A piezoelectric transformer according to claim 9 is incorporated.
Liquid crystal display characterized by the following. 32. The piezoelectric transformer according to claim 10 is incorporated.
Liquid crystal display characterized by the following. 33. The piezoelectric transformer according to claim 11, which is incorporated.
Liquid crystal display characterized by the following. 34. The piezoelectric transformer according to claim 13, which is incorporated.
Liquid crystal display characterized by the following. 35. The piezoelectric transformer according to claim 14, which is incorporated.
Liquid crystal display characterized by the following.