JPH08182310A - High voltage generator - Google Patents

Abstract

PURPOSE: To suitably generate two types of high voltage by effectively using a piezoelectric element while restraining the employment of excess duplicate constituting members. CONSTITUTION: A piezoelectric element 40 is formed by sticking a disclike common electrode 41 to the lower surface of a disclike piezoelectric vibrator 41, and independently sticking semicircular split electrodes 43, 44 to the upper surface of the vibrator 41. In this case, a common electrode 42 is connected to the base of a transistor 21 via a capacitor 23, and the electrode 42 is grounded via the secondary coil 32 of a high-frequency transformer 30. A capacitor 50 forms a serial resonance circuit together with the secondary coil 32 of the transformer 30 and the electrode 43 of the element 40 and the parts of the element 41 and the electrode 42 opposed to the electrode 43. The capacitor 50 is grounded at the one end, and connected to the electrode 42 of the element 40 at the other end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage generator, and more particularly to a high voltage generator which effectively utilizes a piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, in a high voltage generator of this type, as shown in, for example, Japanese Patent Laid-Open No. 60-259770, an oscillation circuit, a capacitor and a piezoelectric element constitute a series resonance circuit. , The resonance frequency of this series resonance circuit causes the piezoelectric element to resonate under the oscillating action of the oscillation circuit to generate a resonance voltage from the common terminal of the piezoelectric element and the capacitor, and this resonance voltage is doubled by a diode. There is one that is rectified to generate a high voltage.

[0003]

By the way, in such a high voltage generator, there is a demand to generate two kinds of high voltages, positive and negative, with respect to the ground potential. However, in order to meet this demand, it is usually necessary to employ one set of piezoelectric elements and one set of oscillation circuits for generation of positive and negative high voltages, respectively. Therefore,
In such a configuration, the same component is used repeatedly, the configuration becomes complicated, and the manufacturing cost increases.

Further, with the high voltage generator as described above, even if the double voltage can be generated by the half-wave rectification by the diode, the resonance voltage is taken out from the piezoelectric element by a single terminal, so that the full-wave rectification is performed. It is difficult to adopt the double voltage method. As a result, with half-wave rectification, there is a problem that only a high voltage that is half that of full-wave rectification can be obtained.

On the other hand, the present inventor has examined the direct extraction of both positive and negative resonance voltages from both electrodes of the piezoelectric element in the series resonance circuit. According to such a method of extracting the resonance voltage, since the capacitor-side electrode of the piezoelectric element is cut off from the oscillation circuit by the piezoelectric element and the capacitor, the resonance voltage is not extracted from the capacitor-side electrode of the piezoelectric element. It is possible. But,
Since the electrode on the oscillation circuit side of the piezoelectric element is directly connected to the oscillation circuit in terms of direct current, the DC component in the oscillation energy of the oscillation circuit is extracted from the electrode on the oscillation circuit side of the piezoelectric element. Therefore, it was found that the direct current level necessary for resonance of the series resonance circuit was shifted, and as a result, the resonance of the series resonance circuit could not be properly maintained.

On the other hand, when the resonance voltage is taken out from the oscillation circuit side electrode of the piezoelectric element through a capacitor or another piezoelectric element, the DC component in the oscillation energy of the oscillation circuit is blocked by the capacitor or another piezoelectric element. . As a result, it has been found that it is possible to extract only the AC component in the oscillation energy, and the resonance of the series resonant circuit can be properly maintained.

Therefore, in order to deal with the above, the present invention suppresses the use of redundant overlapping members and effectively utilizes the piezoelectric element to appropriately generate two types of high voltages. It is an object of the present invention to provide a high voltage generator having the above structure.

[0008]

In order to achieve the above object, in the invention described in claim 1, the common electrode (4
2) and two divided electrodes (43, 44) facing each other, and a common electrode (42) and both divided electrodes (43, 44)
A piezoelectric element (40) forming a series resonance circuit together with the oscillating means (20, 30) and the capacitive elements (50, 50a, 50b) via one side (43), and a piezoelectric element () due to resonance of the series resonance circuit. 40) a first double voltage full wave rectifying means (60, 70) for receiving a resonance voltage from the common electrode (42) through the common electrode (42) and performing double voltage full wave rectification to generate a high voltage; Second voltage-doubler full-wave rectifying means (80, 9) which receives the resonance voltage via the other (44) of both split electrodes (43, 44) and double-voltage full-wave rectifies it to generate a high voltage.
0) and a high voltage generator is provided.

According to the second aspect of the invention,
The common electrode (42) and the divided electrodes (4
3, 44), and the oscillating means (2) via the common electrode (42) and one of the divided electrodes (43, 44) (43).
0, 30) and the capacitive elements (50, 50a, 50b) to form a series resonance circuit, and the one divided electrode (43) from the piezoelectric element (40) due to the resonance of the series resonance circuit. Via a first double voltage full wave rectifying means (60, 70) which receives a resonance voltage via the double voltage full wave rectification and generates a high voltage, and the piezoelectric element (40) via the other split electrode (44). Second voltage doubler full-wave rectifying means (8) that receives the resonant voltage and double-voltage full-wave rectifies it to generate a high voltage
0, 90) is provided.

Further, in the invention described in claim 3,
Oscillation means (20, 30) and first capacitive element (50, 50)
a, 50b) forming a series resonant circuit together with the first capacitive element (50, 50a, 50) from the piezoelectric element (100) due to resonance of the series resonant circuit.
b) First double voltage full-wave rectifying means (60, 70) generated by receiving a resonance voltage via the side electrode (101) and performing double voltage full-wave rectification to generate a high voltage, and its oscillation from the piezoelectric element (100). Second voltage doubler full-wave rectification means (80, which receives a resonance voltage through the means (20, 30) side electrode (102) and the second capacitor element (110) and double-voltage full-wave rectifies it to generate a high voltage.
90) is provided.

According to a fourth aspect of the invention, in the high voltage generator according to the third aspect, the first and second capacitance elements (50, 50a, 50b, 110, 110a, 1) are provided.
At least one of 10b) is a capacitor. In the invention described in claim 5, claim 3
In the high voltage generator described in paragraph 1, the first and second capacitive elements (50, 50a, 50b, 110, 110a, 11).
At least one of 0b) is a piezoelectric element.

According to a sixth aspect of the invention, in the high voltage generator according to any one of the first to fifth aspects,
First and second voltage doubler full-wave rectification means (60, 70, 8)
0, 90) generate high voltages having polarities different from each other. In addition, the reference numerals in parentheses of each of the above-described components indicate the corresponding relationship with the specific components described in the embodiments described later.

[0013]

According to the invention described in claim 1, the piezoelectric element includes a common electrode and both split electrodes, and is connected in series with the oscillation means and the capacitive element via the common electrode and one split electrode. Configure a resonant circuit. Then, the resonance voltage generated from the common electrode of the piezoelectric element is rectified by the first voltage doubler full-wave rectifying means to generate a high voltage, and the resonance voltage generated from the other divided electrode of the piezoelectric element is generated. The second voltage-doubler full-wave rectifying means rectifies the voltage-doubler full-wave to generate a high voltage.

In such a case, since the common electrode is cut off from the oscillating means in a direct current manner by the capacitive element and both divided electrodes are independent of each other, the direct current component of the oscillation energy of the oscillating means is taken out from the common electrode, It is not taken out from the other divided electrode through one divided electrode. Therefore, it is possible to simultaneously take out the resonance voltage from the common electrode and the other divided electrode of the piezoelectric element at the same time, while properly maintaining the resonance of the series resonance circuit without employing an extra duplicate element.

Further, since the common electrode and one of the divided electrodes of the piezoelectric element are independent from each other, the voltage doubler full wave rectification can be performed by the voltage doubler full wave rectification means for each resonance voltage. Therefore, each of the resonant voltages can be obtained as an appropriate high voltage based on these voltage-doubled full-wave rectifications. As a result, a sufficiently high voltage can be secured as compared with the case of half-wave rectification. The function and effect as described above can also be achieved by the invention described in claim 2.

According to the third aspect of the present invention, the piezoelectric element constitutes the series resonance circuit together with the oscillation means and the first capacitance element, and the first voltage doubler full-wave rectification means is the first piezoelectric element. The resonant voltage generated from the electrode on the side of the capacitive element is double-voltage full-wave rectified to generate a high voltage, while the second voltage double-wave full-wave rectification means generates the resonant voltage generated from the electrode on the side of the oscillation means of the piezoelectric element to the second capacitive element. Generated as a high voltage by being doubled and full-wave rectified.

In such a case, the piezoelectric element and the first and second
Since the capacitance elements are independent of each other, the DC component of the oscillation energy of the oscillating means is not taken out from the first capacitance element side electrode of the piezoelectric element or taken out through the second capacitance element. Therefore, while properly maintaining the resonance of the series resonance circuit, it is possible to take out the resonance voltage from the electrode on the first capacitance element side of the piezoelectric element and at the same time take out the resonance voltage from the electrode on the oscillation means side of the piezoelectric element via the second capacitance element. .

Further, since the respective resonance voltage extracting electrodes of the piezoelectric element and the second capacitance element are independent of each other, the double voltage full wave rectification can be performed by the double voltage full wave rectifying means for the respective resonance voltages. As a result, based on these voltage-doubled full-wave rectifications, the above-mentioned resonant voltages can be obtained as sufficiently higher voltages than in the case of half-wave rectification. In such cases, the first
At least one of the second capacitive element and the second capacitive element may be a capacitor as in the invention described in claim 4, or a piezoelectric element as in the invention in claim 5. The same effects as those of the invention described in 3 can be achieved.

According to the sixth aspect of the invention, the first and second voltage doubler full-wave rectification means generate high voltages having polarities different from each other. This allows both positive and negative high voltages to be extracted from a single high voltage generator. As a result, it is possible to provide a useful high voltage generator for an electrostatic actuator or the like that requires both positive and negative high voltages as drive voltages.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows an example in which the high voltage generator according to the present invention is applied to an electrostatic actuator 10. The electrostatic actuator 10 simultaneously receives positive and negative high voltages generated as will be described later from the high voltage generator, and adjusts the light transmission amount of the sun visor or the like of the vehicle.

The high voltage generator includes a transistor circuit 20.
And a high frequency transformer 30 connected to the transistor circuit 20. The transistor circuit 20 includes a transistor 21, which is
At that base, the positive side terminal of the DC power supply +
B is connected. The base of the transistor 21 is connected via a capacitor 23 between a piezoelectric element 40 and a capacitor 50 described later. The emitter of the transistor 21 is grounded.

The high frequency transformer 30 has a ferrite core wound with a primary coil 31 and a secondary coil 32. The primary coil 31 has one end connected to the base of the transistor 21 through a resistor 22. Has been done. The other end of the primary coil 31 is connected to the collector of the transistor 21. The piezoelectric element 40 is shown in FIGS.
, A disk-shaped common electrode 42 is formed on the lower surface of the disk-shaped piezoelectric vibrator 41, while both semi-disk-shaped divided electrodes 43, 44 are formed on the upper surface of the piezoelectric vibrator 41 independently of each other. Are formed and configured. Then, the piezoelectric element 40
Causes the piezoelectric vibrator 41 to vibrate in response to the applied voltage between the common electrode 42 and the divided electrodes 43, and generates the piezoelectric voltage between the common electrode 42 and the divided electrodes 43 and 44.
Here, the common electrode 42 is connected to the base of the transistor 21 through the capacitor 23, and the split electrode 43
Are grounded through the secondary coil 32 of the high frequency transformer 30.

The capacitor 50 constitutes a series resonance circuit together with the secondary coil 32 of the high frequency transformer 30 and the piezoelectric element 40 via the divided electrode 43 and the common electrode 42. The capacitor 50 is grounded at one end thereof. Is
The other end is connected to the common electrode 42 of the piezoelectric element 40. According to the above configuration, the series resonance circuit resonates at its resonance frequency to cause the capacitor 23
The transistor 21 is switched via the. As a result, the high frequency transformer 30 self-excitedly oscillates in response to the switching of the transistor 21, and the DC voltage applied to the primary coil 31 is output from the secondary coil 32 as a high frequency voltage. This means that the piezoelectric element 40 generates the piezoelectric voltage as a resonance voltage.

Both diodes 60 and 70 are connected to the piezoelectric element 40.
A diode 60 is grounded at its anode, and is connected to the common electrode 42 of the piezoelectric element 40 at its cathode, together with a double voltage full-wave rectifier circuit. The diode 70 is connected to the common electrode 42 of the piezoelectric element 40 at its anode. Therefore, both diodes 60 and 70 are connected to the common electrode 42 of the piezoelectric element 40.
The full-wave rectification of the resonance voltage from the above is performed as a negative high voltage and output from the cathode of the diode 70.

Both diodes 80 and 90 form a voltage doubler full-wave rectifier circuit together with the piezoelectric element 40. The diode 80 is grounded at its cathode, while the anode of the diode 80 divides the piezoelectric element 40. It is connected to the electrode 44. The diode 90 is connected to the split electrode 44 of the piezoelectric element 40 at its cathode. Therefore, the diodes 80 and 90 double-wave full-wave rectify the resonance voltage from the divided electrodes of the piezoelectric element 40 and output it as a positive high voltage from the anode of the diode 90.

In the first embodiment constructed as described above, when a DC voltage is applied to the primary coil 31 of the high frequency transformer 30 from the DC power source, the high frequency transformer 30
Secondary coil 32, piezoelectric element 40 and capacitor 50
Directly constitutes a resonance circuit and resonates. Therefore, in response to the switching action of the transistor 21 due to this resonance, the high frequency transformer 30 self-excitedly oscillates to maintain the above resonance phenomenon. Therefore, the piezoelectric element 40 generates a resonance voltage between the common electrode 42 and the polarized electrode 43.

In this case, the common electrode 42 is the capacitor 50.
Thus, the high frequency transformer 30 is cut off from the high frequency transformer 30 in a direct current manner, and the split electrode 43 is cut off from the high frequency transformer 30 in a direct current manner. Therefore, only the AC component of the oscillation energy of the high frequency transformer 30 excluding the DC component is transmitted to the common electrode 42 side and the split electrode 44 side.

As a result, a negative resonance voltage is generated in the common electrode 42 with reference to the ground potential, while the polarization electrode 44 is generated.
A positive resonance voltage is generated at. Here, as mentioned above,
Since both diodes 60 and 70 form a voltage doubler full-wave rectifier circuit together with the piezoelectric element 40, the negative voltage generated in the common electrode 42 is voltage-doubler full-wave rectified by the voltage doubler full-wave rectifier circuit to obtain a negative high voltage. The voltage is output from the cathode of the diode 70. On the other hand, as described above, both diodes 8
Since 0 and 90 form a voltage doubler full-wave rectifier circuit together with the piezoelectric element 40, the voltage doubler wave full-wave rectifier circuit double-voltage full-wave rectifies the positive resonance voltage generated in the common electrode 44 to obtain a positive high voltage. It is output from the anode of the diode 90.

As described above, in the first embodiment,
Since the electrode facing the common electrode 42 of the piezoelectric element 40 is composed of the divided electrodes 43 and 44 which are independent from each other, the piezoelectric element 40 is self-excited by the resonance of the series resonance circuit. Negative and positive resonance voltages can be simultaneously taken out from the common electrode 42 and the divided electrodes 44. Accordingly, with a simple structure of the single piezoelectric element 40, it is possible to provide a high voltage generator for the electrostatic actuator 10 that simultaneously requires positive and negative high voltages.

In such a case, as described above, the positive and negative resonance voltages are extracted from one of the split electrodes 44 and the common electrode 42 which are independent of each other, so that the direct current component in the oscillation energy of the high frequency transformer 30 flows out. It is possible to properly maintain the resonance phenomenon of the series resonance circuit without causing the above. In addition, the common electrode 42 and the divided electrode 4 of the piezoelectric element 40
Since 4 are independent of each other with different polarities, positive and negative two types of high voltages can be properly taken out simultaneously from the single piezoelectric element 40 by the double voltage full-wave rectifier circuit. Moreover, the electrostatic actuator 10 can be efficiently driven by such positive and negative high voltages.

FIG. 4 shows a modification of the first embodiment. In this modification, each electrode of the piezoelectric element 40 described in the first embodiment is the case of the first embodiment. Its structural feature is that it is used with the opposite polarity. That is, the common electrode 42 of the piezoelectric element 40 is grounded through the secondary coil 32 of the high frequency transformer 30. The split electrode 43 is grounded through the capacitor 50 and is also connected to the base of the transistor 21 through the capacitor 23. On the other hand, the split electrode 44
Are connected to the anode of the diode 80 and the cathode of the diode 90. The other structure is similar to that of the first embodiment.

In this modified example thus constructed, the piezoelectric element 40 and the piezoelectric vibration facing the polarized electrode 43 are caused by the resonance phenomenon similar to that described in the first embodiment. A resonance voltage is generated between the child 41 and each part of the common electrode 42. As a result, a negative resonance voltage is generated at the split electrode 43, and a positive resonance voltage is generated at the split electrode 44, with reference to the ground potential.

Then, a negative high voltage is generated based on the resonance voltage from the divided electrode 43 under the double voltage full-wave rectification action of both diodes 60, 70, while both diodes 80,
A positive high voltage is generated based on the resonance voltage from the divided electrode 44 under the double voltage full-wave rectification action of 90. as a result,
The same effects as those described in the first embodiment can also be achieved in this modification.

FIG. 5 shows a second embodiment of the present invention. In this second embodiment, instead of the piezoelectric element 40 described in the first embodiment, a pair of piezoelectric elements 100, 1 is used.
10 is adopted. The piezoelectric element 100 has its negative electrode 101 grounded through the capacitor 50 and connected to the base of the transistor 21 through the capacitor 23. On the other hand, the positive electrode 102 of the piezoelectric element 100 is grounded through the secondary coil 32 of the high frequency transformer 30.

The piezoelectric element 110 has a negative electrode 1
At 11, the positive electrode 102 of the piezoelectric element 100 is connected, and the positive electrode 112 of the piezoelectric element 110 is connected to the anode of the diode 80 and the cathode of the diode 90. In the second embodiment, the piezoelectric element 1
10 functions as a capacitance element similar to a capacitor. Thereby, the secondary coil 3 of the high frequency transformer 30
Of the oscillation energy generated at the common connection point between the piezoelectric element 100 and the positive electrode 102 of the piezoelectric element 100, only the AC component other than the DC component is extracted to the both diodes 80, 90 side via the piezoelectric element 110.

However, since the piezoelectric element is excellent in pressure resistance and capacitance, the outer dimension of the piezoelectric element 110 is considerably smaller than the outer dimension of a capacitor having the same pressure resistance and electrostatic property. The other structure is the same as that of the first embodiment. In the second embodiment thus configured, the capacitor 50 constitutes the series resonance circuit together with the secondary coil 32 of the high frequency transformer 30 and the piezoelectric element 100. Therefore, the piezoelectric element 100 generates a resonance voltage under the self-excited oscillation of the high frequency transformer 30 due to the resonance of the series resonance circuit. At this time, a negative resonance voltage appears on the electrode 101, while a positive resonance voltage appears on the electrode 102.

Therefore, the diodes 60 and 70 double-wave full-wave rectify the resonance voltage from the electrode 101 of the piezoelectric element 100 to generate a negative high voltage. On the other hand, both diodes 80,
90 is the electrode 1 of the piezoelectric element 100 via the piezoelectric element 110.
02 receives the resonance voltage and performs double-wave full-wave rectification to generate a positive high voltage. In such a case, the DC component of the oscillation energy of the high frequency transformer 30 is blocked from both the diodes 80 and 90 by the electrostatic capacitance action of the piezoelectric element 110.
In other words, since the resonance voltage from the electrode 102 of the piezoelectric element 100 is properly taken out through the piezoelectric element 110 in a state where the resonance phenomenon of the series resonance circuit is properly maintained, the positive voltage generated by the double voltage full-wave rectification circuit is increased. It is possible to properly take out each negative voltage and negative high voltage.

Here, the piezoelectric element 110 is the piezoelectric element 100.
Since it oscillates at a frequency that is slightly deviated from the resonance frequency of, there is a slight loss, but a full-wave rectified current that is approximately doubled can be obtained. When this is compared with the case where both piezoelectric elements 100 and 110 are connected in parallel, both piezoelectric elements 100 and 110 are compared with the case where both piezoelectric elements 100 and 110 are connected in parallel (see the solid line in FIG. 6). It has been confirmed that the generated outflow and the outflow can be obtained twice in the case of connecting in series (see the broken line in FIG. 6).

When the two piezoelectric elements 100 and 110 are connected in parallel, the change as shown by the solid line in FIG. 6 is due to the following reason. Generally, the magnitude of the current generated by the piezoelectric element increases as the internal impedance at resonance of the piezoelectric element decreases. The internal impedance of the piezoelectric element 100 or 110 is determined by the diameter and thickness of the piezoelectric element, but this internal impedance is not inversely proportional to the surface area of the piezoelectric element, and even if the surface area is doubled, it is 1 / Because it does not go down to 2.

FIG. 7 shows a first modification of the second embodiment. In the first modification, the cathode of the diode 70 is grounded via the smoothing capacitor 120 and the capacitor 120 is resistive. 130 are connected in parallel. On the other hand, the anode of the diode 90 is grounded via the smoothing capacitor 140, and the resistor 150 is connected in parallel to this capacitor 140.

According to this first modification, the diode 7
Since the high voltages from 0 and 90 are smoothed by the capacitors 120 and 140, respectively, the usage state of the current after the double voltage full-wave rectification is good. Also, the resistors 130, 1
By 50, it is possible to suppress the fluctuation of the high voltage due to the presence or absence of a load. This means that the resistors 130 and 150 have a role of lowering the internal impedance of the high voltage generator.

Therefore, according to the first modification, it is possible to provide a high voltage generator which is even easier to use. In addition,
The input / output voltage characteristics of the high voltage generator according to the first modified example were obtained as shown in FIG. According to this, an output voltage of 600 V was obtained on both positive and negative sides, for example, when the input voltage was 9 V and the load resistance was 1 MΩ.

FIG. 9 shows a second modification of the second embodiment. In this second modification, instead of the piezoelectric element 110 in the second embodiment, this piezoelectric element 110 is used.
The structure is characterized in that the capacitor 110a having the same electrostatic capacity as that of 1. is adopted. This makes the book second
The modified example can also achieve the same effect as the second embodiment.

FIG. 10 shows a third modification of the second embodiment. In this third modification, instead of the capacitor 50 and the piezoelectric element 110 in the second embodiment, a piezoelectric element 50a and a piezoelectric element 50a are provided. Each of the capacitors 110b has a feature in its configuration. In such cases,
The piezoelectric element 50a and the capacitor 110b are respectively
It has the same function as the capacitor 50 and the piezoelectric element 110.

As a result, the same operational effect as that of the second embodiment can be achieved by the third modification as well. Figure 11
Shows a fourth modification of the second embodiment. In this fourth modification, instead of the capacitor 50 in the second embodiment, a piezoelectric element having the same capacitance as this capacitor 50. The feature of the configuration is that the 50b is adopted.

As a result, the fourth modification can also achieve the same effects as the second embodiment. In the fourth modified example, as shown in FIG. 12, the cathode of the diode 70 is grounded via the smoothing capacitor 120a and the resistor 130 is connected to the capacitor 120a.
a may be connected in parallel, while the anode of the diode 90 may be grounded via the smoothing capacitor 140a and a resistor 150a may be connected in parallel to this capacitor 140a.

As a result, the high voltages from the diodes 70 and 90 are smoothed by the capacitors 120a and 140a, respectively, so that the usage state of the current after the double voltage full-wave rectification becomes good. Further, the resistors 130a and 150a can suppress the fluctuation of the high voltage due to the presence or absence of the load. This means that the resistors 130a and 150a have a role of lowering the internal impedance of the high voltage generator. As a result, it is possible to provide a high voltage generator that is even easier to use.

13 to 15 show a third embodiment of the present invention. In the third embodiment, a piezoelectric element 160 is adopted in place of the piezoelectric element 40 and the capacitor 50 in the first embodiment. In particular, there is a feature in its structure. In the piezoelectric element 160, the negative side arcuate plate-shaped divided electrodes 162 and 163 are formed on the lower surface of the disk-shaped piezoelectric vibrator 161, while the positive side arcuate plate-shaped divided electrode is formed on the upper surface of the piezoelectric vibrator 161. 164 and 165 are formed.

In this case, the central angles of the divided electrodes 162 and 163 are, for example, 240 ° and 120 °, respectively (see FIG. 14), while the divided electrodes 164 are formed.
The central angles of 165 and 165 are 120 degrees and 240 degrees, respectively (see FIG. 15). In addition, the divided electrode 162 has arcuate portions 162a having a central angle of 120 degrees,
162b, while the split electrode 165 has a central angle of 12
It consists of arcuate portions 165a, 165b of 0 degree. The arc-shaped portion 162a faces the divided electrode 164 via the piezoelectric vibrator 161, the arc-shaped portion 162b faces the arc-shaped portion 165a via the piezoelectric vibrator 161, and
The divided electrode 163 faces the arc-shaped portion 165b via the piezoelectric vibrator 161.

The split electrode 162 is composed of the diode 60.
And the anode of the diode 70, and is also connected to the base of the transistor 21 through the capacitor 23. The split electrode 163 is connected to the anode of the diode 80 and the cathode of the diode 90. The split electrode 164 is grounded, and the split electrode 165 is grounded through the secondary coil 32 of the high frequency transformer 30.

In such a piezoelectric element 160, the arc-shaped portion 162a, the portion of the piezoelectric vibrator 161 facing the arc-shaped portion 162a, and the divided electrode 164 have the same function as the capacitor 50 in the first embodiment. In addition, the split electrode 16
5, the portion of the piezoelectric vibrator 161, the arc-shaped portion 162b, and the divided electrode 163 facing the same have the same function as the piezoelectric element 40 described in the first embodiment.

As a result, the series resonance of the piezoelectric element 160 and the secondary coil 32 of the high frequency transformer 30 is constituted by the piezoelectric element 40, the capacitor 50 and the secondary coil 32 of the high frequency transformer 30 described in the first embodiment. A series resonant circuit similar to the circuit is constructed. As a result, according to the third embodiment, it is possible to achieve the same effect as that of the first embodiment by adopting the single piezoelectric element 160 without using the capacitor 50 as a separate component.

In implementing the present invention, not only the oscillation circuit including the transistor circuit 20 and the high frequency transformer 30, but an oscillation circuit capable of forming a series resonance circuit including a piezoelectric element is sufficient. Further, in carrying out the present invention, one of the positive and negative high voltages from the double voltage rectifier circuit in each of the above embodiments may be inverted in polarity so that both of them are taken out as a high voltage having the same polarity. . As a result, it is possible to appropriately generate two types of high voltage having the same polarity while being cut off from the high frequency transformer 30 in terms of direct current.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a bottom view of the piezoelectric element shown in FIG.

FIG. 3 is a top view of the piezoelectric element shown in FIG.

FIG. 4 is a circuit configuration diagram showing a modified example of the first embodiment.

FIG. 5 is a circuit configuration diagram showing a second embodiment of the present invention.

FIG. 6 is a graph comparing generated currents in the case of both piezoelectric elements connected in series in FIG. 5 with those in the case of connecting both piezoelectric elements in parallel.

FIG. 7 is a circuit configuration diagram showing a first modification of the second embodiment.

8 is a graph showing input / output voltage characteristics in the configuration of FIG.

FIG. 9 is a circuit configuration diagram showing a second modification of the second embodiment.

FIG. 10 is a circuit configuration diagram showing a third modification of the second embodiment.

FIG. 11 is a circuit configuration diagram showing a fourth modification of the second embodiment.

FIG. 12 is a circuit configuration diagram showing a partially modified example of the fourth modified example.

FIG. 13 is a circuit configuration diagram showing a third embodiment of the present invention.

FIG. 14 is a bottom view of the piezoelectric element shown in FIG.

FIG. 15 is a top view of the piezoelectric element shown in FIG.

[Explanation of symbols]

20 ... Transistor circuit, 30 ... High frequency transformer, 40, 50a, 50b, 110 ... Piezoelectric element, 4
2 ... common electrode, 43, 44 ... split electrode, 50,
110a, 110b ... capacitors, 60, 70, 8
0, 90 ... Diode.

Claims (6)

[Claims] 1. A piezoelectric element having a common electrode and both split electrodes facing the common electrode, the piezoelectric element forming a series resonance circuit together with an oscillation means and a capacitive element via one of the common electrode and the both split electrodes. A first voltage doubler full-wave rectifying unit that receives a resonance voltage from the piezoelectric element via the common electrode thereof due to resonance of the series resonance circuit and performs double-voltage full-wave rectification to generate a high voltage. A high voltage generator comprising a second voltage doubler full wave rectifying means for receiving a resonance voltage via the other of the split electrodes and performing double voltage full wave rectification to generate a high voltage. 2. A piezoelectric element having a common electrode and both split electrodes facing the common electrode, the piezoelectric element forming a series resonance circuit together with an oscillating means and a capacitive element via one of the common electrode and the both split electrodes. First double voltage full-wave rectifying means for generating a high voltage by receiving a resonance voltage from the piezoelectric element through one of the divided electrodes and performing double-wave full-wave rectification with resonance of the series resonance circuit; A high voltage generator comprising a second voltage doubler full wave rectifying means for receiving a resonance voltage via the other divided electrode and performing double voltage full wave rectification to generate a high voltage. 3. A piezoelectric element that forms a series resonance circuit together with an oscillating means and a first capacitance element, and a resonance voltage from the piezoelectric element that passes through the first capacitance element side electrode when the series resonance circuit resonates, and doubles the resonance voltage. A first voltage-doubler full-wave rectifier that is generated by voltage full-wave rectification and a high voltage, and a voltage-doubler full-wave rectifier that receives a resonance voltage from the piezoelectric element via its oscillation-side electrode and a second capacitor element. And a second voltage doubler full-wave rectifier that generates a voltage. 4. The high voltage generator according to claim 3, wherein at least one of the first and second capacitance elements is a capacitor. 5. The high voltage generator according to claim 3, wherein at least one of the first and second capacitance elements is a piezoelectric element. 6. The high voltage generator according to claim 1, wherein the first and second voltage doubler full-wave rectifiers generate high voltages having polarities different from each other.