JP3339224B2 - High voltage generator - Google Patents

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 using piezoelectric elements effectively.

[0002]

2. Description of the Related Art Conventionally, in this type of high-voltage generator, a series resonance circuit is constituted by an oscillation circuit, a capacitor and a piezoelectric element as disclosed in Japanese Patent Application Laid-Open No. 60-259770, for example. The piezoelectric element is resonated at the resonance frequency of the series resonance circuit under the oscillating action of the oscillation circuit to generate a resonance voltage from the common terminal of the piezoelectric element and the capacitor. Some rectifiers generate a high voltage.

[0003]

However, in such a high voltage generator, there is a demand to generate two types of positive and negative high voltages with respect to the ground potential. However, in order to meet this demand, it is usually necessary to employ one set of piezoelectric element and one set of oscillating circuit for generating positive and negative high voltages. Therefore,
In such a configuration, the same components are repeatedly used, resulting in a problem that the configuration is complicated and the manufacturing cost is increased.

In the high voltage generator as described above, even if a double voltage can be generated by half-wave rectification using a diode, since a single terminal is provided for extracting a resonance voltage from the piezoelectric element, full-wave rectification is used. It is difficult to adopt the voltage doubler method. As a result, there is a problem in that the half-wave rectification can provide only a high voltage that is half that of the full-wave rectification.

[0005] 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 DC from the oscillation circuit by the piezoelectric element and the capacitor, the resonance voltage is extracted from the capacitor-side electrode of the piezoelectric element. It is possible. But,
Since the oscillation circuit side electrode of the piezoelectric element is directly connected to the oscillation circuit in a DC manner, a DC component in the oscillation energy of the oscillation circuit is extracted from the oscillation circuit side electrode of the piezoelectric element. For this reason, it has been found that the DC level required for the resonance of the series resonance circuit shifts, and as a result, the resonance of the series resonance circuit cannot be properly maintained.

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

[0007] In view of the above, the present invention has been made to appropriately generate two kinds of high voltages by effectively utilizing the piezoelectric element while suppressing the use of an unnecessary overlapping component. It is an object of the present invention to provide a high-voltage generating device.

[0008]

According to the first aspect of the present invention, there is provided a disk-shaped piezoelectric vibrator.
A moving element (41) and formed on one surface of the piezoelectric vibrator (41)
Disc-shaped common electrode (42) and the piezoelectric vibrator
(41) a semi-disc-shaped split electrode (43, 44) formed on the other surface facing the common electrode (42), and the common electrode (42) and the split electrode (43, 44); And a piezoelectric element (40) forming a series resonance circuit together with the oscillating means (20, 30) and the capacitance element (50, 50a, 50b) via one of the (43), and a piezoelectric element ( A first voltage doubler full-wave rectifier (60, 70) which receives a resonance voltage from the common electrode (42) via the common electrode (42) and generates a double voltage full-wave rectification as a high voltage; The other (4) of the two split electrodes (43, 44)
Second voltage double voltage full-wave rectifier (80, 90) which receives the resonance voltage via 4) and generates a double voltage full-wave rectification as a high voltage
And a high voltage generator comprising:

Further, in the invention according to claim 2,
A disk-shaped piezoelectric vibrator (41) and the piezoelectric vibrator (4
1) a disc-shaped common electrode (42) formed on one surface ;
The common electrode formed on the other surface of the piezoelectric vibrator (41)
(42) , two semi-circular disc-shaped split electrodes (43, 4
4), and the common electrode (42) and both split electrodes (4
Oscillating means (20, 3) via one (43) of the
0) and a capacitive element (50, 50a, 50b) and a piezoelectric element (40) forming a series resonance circuit, and the piezoelectric element (40) is coupled via the one split electrode (43) with the resonance of the series resonance circuit. First voltage doubler full-wave rectifying means (6) which receives the resonance voltage and generates double voltage full-wave rectification and generates a high voltage.
0, 70) and a second voltage doubler full wave rectifier (80, 70) which receives a resonance voltage from the piezoelectric element (40) via the other split electrode (44) and doubles voltage full wave rectification to generate a high voltage.
90).

Further, in the invention according to claim 3,
A disk-shaped piezoelectric vibrator (161) and the piezoelectric vibrator (1
61) First and second arcuate plate-shaped divisions formed on one surface
In addition to the electrodes (162, 163) and the piezoelectric vibrator (161)
Arc-shaped third and fourth divided electrodes (16
4, 165) and the first divided electrode (162).
Are the first and second arc-shaped portions (162a, 162b)
And the fourth divided electrode (165) includes third and fourth electrodes.
Arc-shaped portions (165a, 165b),
One arc-shaped portion (162a) is connected to the third divided electrode (1
64), the second arc-shaped portion (162b)
The second arc-shaped portion (165a) is opposed to the second arc-shaped portion (165a).
Is divided into the fourth arc-shaped portions (165).
b), the first arc-shaped portion (162)
a), a portion of the piezoelectric vibrator (161) opposed thereto;
And the third divided electrode (164) is similar to the capacitive element.
A portion having the function of the third arc-shaped portion
Minute (165a) and said second arc-shaped portion (162b)
Through the oscillation means (20, 30) and the capacitive element.
A piezoelectric element (160) that forms a series resonance circuit together with a portion having the same function, and the first split electrode (16 ) is separated from the piezoelectric element (160) by resonance of the series resonance circuit.
First voltage doubler full-wave rectifier (60, 70) which receives the resonance voltage via 2) and generates a double voltage full-wave rectification as a high voltage
And the second split electrode from the piezoelectric element (160).
A second voltage doubler full-wave rectifier (80,
90).

According to a fourth aspect of the present invention, in the high voltage generator according to the third aspect, the first divided power supply
The central angle of the pole (162) is 240 degrees,
The central angle of the split electrode (163) is 120 degrees . According to a fifth aspect of the present invention, in the high voltage generator according to the third aspect, the fourth divided electrode is provided.
The central angle of (165) is 240 degrees, and the third division
The center angle of the electrode (164) is 120 degrees .

[0012] The Contact, reference numerals in parentheses of the above respective components are those which show the correspondence with specific components of an embodiment according to later.

[0013]

According to the first aspect of the present invention, the piezoelectric element includes the 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. Construct a resonance circuit. Then, a resonance voltage generated from the common electrode of the piezoelectric element is generated as a high voltage by double voltage full wave rectification by the first voltage doubler full wave rectifier, while a resonance voltage generated from the other divided electrode of the piezoelectric element is generated. The second voltage doubler full-wave rectifier generates a double voltage full-wave rectifier as a high voltage.

In such a case, since the common electrode is cut off from the oscillating means by the capacitive element in a DC manner and the divided electrodes are independent of each other, the DC component of the oscillating energy of the oscillating means can be extracted from the common electrode. It is not taken out of one of the divided electrodes from the other. Accordingly, the resonance voltage can be simultaneously taken out from the common electrode and the other divided electrode of the piezoelectric element while maintaining the resonance of the series resonance circuit properly without using an extra redundant element.

Further, since the common electrode and one of the divided electrodes of the piezoelectric element are independent of each other, it is possible to perform the voltage doubler full wave rectification by the voltage doubler full wave rectifier for each resonance voltage. For this reason, based on these doubled voltage full-wave rectifications, it is possible to obtain the respective resonance voltages as appropriate high voltages. As a result, a sufficiently high voltage can be secured as compared with the case of half-wave rectification. The above operation and effect can also be achieved by the invention described in claim 2.

[0016]

[0017]

[0018]

[0019]

[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 from the high voltage generator as described later, and adjusts the amount of light transmitted by a sun visor or the like of the vehicle.

The high-voltage generating device 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. The transistor 21
At its base, the positive terminal of the DC power
B. The base of the transistor 21 is connected via a capacitor 23 between a later-described piezoelectric element 40 and a capacitor 50. Note that the emitter of the transistor 21 is grounded.

The high-frequency transformer 30 has a primary coil 31 and a secondary coil 32 wound around a ferrite core. The primary coil 31 has one end connected to the base of the transistor 21 through the resistor 22. Have been. 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.
As shown in the figure, a disc-shaped common electrode 42 is formed on the lower surface of the disc-shaped piezoelectric vibrator 41, while the semi-disc-shaped split electrodes 43 and 44 are independently formed on the upper surface of the piezoelectric vibrator 41. It is formed and formed. And this piezoelectric element 40
Causes the piezoelectric vibrator 41 to vibrate in response to a voltage applied between the common electrode 42 and the split electrode 43 to generate a piezoelectric voltage between the common electrode 42 and the split electrodes 43 and 44.
Here, the common electrode 42 is connected to the base of the transistor 21 through the capacitor 23,
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 and the piezoelectric element 40 of the high-frequency transformer 30 through the divided electrode 43 and the common electrode 42. The capacitor 50 has one end grounded. And
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
The transistor 21 is switched via the switch. As a result, the high-frequency transformer 30 self-oscillates in response to the switching of the transistor 21, and outputs a DC voltage applied to the primary coil 31 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.

The diodes 60 and 70 are connected to the piezoelectric element 40.
The diode 60 is connected to the common electrode 42 of the piezoelectric element 40 at its cathode while its anode is grounded. The diode 70 has its anode connected to the common electrode 42 of the piezoelectric element 40. Therefore, both diodes 60 and 70 are connected to the common electrode 42 of the piezoelectric element 40.
From the cathode of the diode 70 as a negative high voltage.

The diodes 80 and 90 together with the piezoelectric element 40 constitute a voltage doubler full-wave rectifier circuit. The diode 80 is grounded at its cathode, and is divided at its anode. It is connected to the electrode 44. The diode 90 is connected at its cathode to the split electrode 44 of the piezoelectric element 40. For this reason, both diodes 80 and 90 double-voltage full-wave rectify the resonance voltage from the divided electrodes of the piezoelectric element 40 and output the same from the anode of the diode 90 as a positive high voltage.

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

In this case, the common electrode 42 is connected to the capacitor 50
As a result, the DC is cut off from the high-frequency transformer 30 and the split electrode 44 is cut off DC from the high-frequency transformer 30 by the split electrode 43. 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 at the common electrode 42 with reference to the ground potential, while the polarization electrode 44 is
Generates a positive resonance voltage. Here, as described above,
Since the diodes 60 and 70 together with the piezoelectric element 40 constitute a voltage doubler full-wave rectifier circuit, the voltage doubler full-wave rectifier rectifies the negative resonance voltage generated at the common electrode 42 by the voltage doubler full-wave rectifier to produce 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 constitute a voltage doubler full-wave rectifier circuit together with the piezoelectric element 40, the positive resonance voltage generated at the common electrode 44 is double-voltage double-wave rectified by the voltage doubler full-wave rectifier circuit to become a positive high voltage. 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 constituted by the split electrodes 43 and 44 independent of each other, the piezoelectric element 40 is self-oscillated by the high-frequency transformer 30 due to the resonance of the series resonance circuit. Negative and positive resonance voltages can be simultaneously extracted from the common electrode 42 and the split electrode 44. Thus, with a simple configuration of a single piezoelectric element 40, it is possible to provide a high-voltage generator for the electrostatic actuator 10 that requires both positive and negative high voltages at the same time.

In such a case, as described above, the positive and negative resonance voltages are taken out from one of the two divided electrodes 44 and the common electrode 42, so that the DC component in the oscillation energy of the high-frequency transformer 30 flows out. The resonance phenomenon of the series resonance circuit can be appropriately maintained without accompanying the above. Further, the common electrode 42 and the divided electrode 4 of the piezoelectric element 40
4 are independent of each other with different polarities, two positive and negative high voltages can be simultaneously and properly extracted from the single piezoelectric element 40 by the double voltage full-wave rectifier circuit. Further, 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, the electrodes of the piezoelectric element 40 described in the first embodiment are different from those of the first embodiment. There is a structural feature in that it is used with a polarity opposite to that of FIG. 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 a capacitor 50 and connected to the base of the transistor 21 through a 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. Other configurations are the same as in the first embodiment.

In this modified embodiment, the piezoelectric element 40 is driven by the polarization element 43 and the piezoelectric vibrator opposing the polarization electrode 43 under the same resonance phenomenon as described in the first embodiment. A resonance voltage is generated between the element 41 and each part of the common electrode 42. As a result, a negative resonance voltage is generated at the divided electrode 43 with reference to the ground potential, while a positive resonance voltage is generated at the divided electrode 44.

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

FIG. 5 shows a second embodiment of the present invention. In the second embodiment, a pair of piezoelectric elements 100, 1 and 1 are used instead of the piezoelectric element 40 described in the first embodiment.
10 are employed. The piezoelectric element 100 is grounded at its negative electrode 101 through a capacitor 50 and connected to the base of the transistor 21 through a 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, it is connected to the positive electrode 102 of the piezoelectric element 100, 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
Reference numeral 10 functions as a capacitance element similar to a capacitor. Thereby, the secondary coil 3 of the high-frequency transformer 30
Of the oscillating energy generated at the common connection point between the second element 2 and the positive electrode 102 of the piezoelectric element 100, only the AC component other than the DC component is extracted to both diodes 80 and 90 via the piezoelectric element 110.

However, since the piezoelectric element has excellent pressure resistance and capacitance, the external dimensions of the piezoelectric element 110 are considerably smaller than the external dimensions of a capacitor having similar pressure resistance and electrostatic properties. The other configuration is the same as that of the first embodiment. In the second embodiment configured as described above, the capacitor 50 forms a series resonance circuit together with the secondary coil 32 and the piezoelectric element 100 of the high-frequency transformer 30. Therefore, the piezoelectric element 100 generates a resonance voltage under self-excited oscillation of the high-frequency transformer 30 due to 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.

Accordingly, both diodes 60 and 70 double-wave rectify the resonance voltage from electrode 101 of 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 voltage 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 cut off from the diodes 80 and 90 by the 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 by the double voltage full-wave rectifier circuit is obtained. And appropriate extraction of each negative high voltage.

Here, the piezoelectric element 110 is
Vibrates at a frequency slightly deviated from the resonance frequency of the above, and although there is a slight loss, an almost double full-wave rectified current can be obtained. When this is compared with the case where both the piezoelectric elements 100 and 110 are connected in parallel, compared with the case where both the piezoelectric elements 100 and 110 are connected in parallel (see the solid line in FIG. 6), both the piezoelectric elements 100 and 110 are connected. Were connected in series (see the broken line in FIG. 6), it was confirmed that the generated outflow could be obtained with twice the size.

In the case where the two piezoelectric elements 100 and 110 are connected in parallel, the reason for the change as shown by the solid line in FIG. 6 is as follows. Normally, the magnitude of the current generated by the piezoelectric element increases as the internal impedance of the piezoelectric element at resonance decreases. The internal impedance of the piezoelectric element 100 or 110 is determined by the diameter and the thickness of the piezoelectric element. However, the internal impedance is not inversely proportional to the surface area of the piezoelectric element. Because it does not drop to 2.

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

According to the first modification, the diode 7
Since the high voltages from 0 and 90 are smoothed by the capacitors 120 and 140, respectively, the use state of the current after the double voltage full-wave rectification is improved. Further, each resistor 130, 1
With 50, the fluctuation of high voltage due to the presence or absence of a load can be suppressed. This means that each of the resistors 130 and 150 has a role of lowering the internal impedance of the high voltage generator.

Therefore, according to the first modified example, it is possible to provide a high-voltage generating device that is 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 the positive and negative sides at a load resistance of 1 MΩ with respect to an input voltage of 9 V, for example.

FIG. 9 shows a second modification of the second embodiment. In the second modification, the piezoelectric element 110 is replaced with the piezoelectric element 110 of the second embodiment.
There is a feature in the configuration in that the capacitor 110a having the same capacitance as that described above is employed. As a result, the second
According to the modification, the same operation and effect as those of the second embodiment can be achieved.

FIG. 10 shows a third modification of the second embodiment. In this third modification, the piezoelectric element 50a and the piezoelectric element 110 are replaced with the piezoelectric element 50a and the piezoelectric element 110 of the second embodiment. The adoption of each of the capacitors 110b has a structural feature. 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.

Thus, according to the third modification, the same operation and effect as those of the second embodiment can be achieved. FIG.
Shows a fourth modification of the second embodiment. In this fourth modification, a piezoelectric element having the same capacitance as that of the capacitor 50 is used instead of the capacitor 50 of the second embodiment. The use of the 50b has a structural feature.

Thus, according to the fourth modification, the same operation and effect as those of the second embodiment can be achieved. In the fourth modification, as shown in FIG. 12, the cathode of the diode 70 is grounded via a smoothing capacitor 120a, and a resistor 130 is connected to the capacitor 120a.
a, the anode of the diode 90 may be grounded via a smoothing capacitor 140a, and the resistor 150a may be connected in parallel to the 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 use state of the current after the double voltage full-wave rectification is improved. In addition, fluctuations in high voltage due to the presence or absence of a load can be suppressed by the resistors 130a and 150a. This means that each of the resistors 130a and 150a has 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 easier to use.

FIGS. 13 to 15 show a third embodiment of the present invention. In this third embodiment, a piezoelectric element 160 is employed in place of the piezoelectric element 40 and the capacitor 50 in the first embodiment. In particular, there is a characteristic in its configuration. The piezoelectric element 160 has negative arc-shaped plate-shaped divided electrodes 162 and 163 formed on the lower surface of a disk-shaped piezoelectric vibrator 161, and a positive arc-shaped plate-shaped divided electrode on the upper surface of the piezoelectric vibrator 161. 164 and 165 are formed.

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

The split electrode 162 is connected to the diode 60
And the anode of the diode 70, and is 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 split electrode 164 have the same functions as the capacitor 50 in the first embodiment. In addition, the split electrode 16
5, the portion of the piezoelectric vibrator 161 opposed thereto, the arc-shaped portion 162b, and the divided electrode 163 have the same function as the piezoelectric element 40 described in the first embodiment.

As a result, the piezoelectric element 160 and the secondary coil 32 of the high frequency transformer 30 are connected to the series resonance of 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 resonance circuit similar to the circuit is configured. As a result, according to the third embodiment, the same operation and effect as those of the first embodiment can be achieved without employing the capacitor 50 as a separate component and employing the single piezoelectric element 160.

In practicing the present invention, an oscillation circuit that can form a series resonance circuit including a piezoelectric element is sufficient without being limited to the oscillation circuit including the transistor circuit 20 and the high-frequency transformer 30. Further, in practicing 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 to take out both as high voltages of the same polarity. . This makes it possible to properly generate two types of high voltages having the same polarity in a state where the high-frequency transformer 30 is cut off in a DC manner.

[Brief description of the drawings]

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

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

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

FIG. 4 is a circuit diagram showing a modification of the first embodiment.

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

6 is a graph comparing the current generated in the case of both piezoelectric elements connected in series in FIG. 5 with the case where both piezoelectric elements are connected in parallel.

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

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

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

FIG. 12 is a circuit diagram showing a partial modification of the fourth modification.

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

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

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

[Explanation of symbols]

Reference numeral 20: transistor circuit, 30: high-frequency transformer, 40, 50a, 50b, 110: piezoelectric element, 4
2 ... common electrode, 43, 44 ... divided electrode, 50,
110a, 110b ... capacitors, 60, 70, 8
0, 90... Diodes.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 3/24 H02M 7/10

Claims (5)

(57) [Claims] 1. A disk-shaped piezoelectric vibrator, and the piezoelectric vibrator
A disk-shaped common electrode formed on one surface of the piezoelectric vibrator;
A semi-disc-shaped divided electrode formed on the other surface of the element and facing the common electrode, and is connected in series with an oscillating means and a capacitive element via one of the common electrode and the divided electrodes. A piezoelectric element forming a resonance circuit; and a first voltage doubler full-wave rectifier that receives a resonance voltage from the piezoelectric element via its common electrode and generates a double-voltage full-wave rectifier as a high voltage with the resonance of the series resonance circuit. And a second voltage doubler full-wave rectifier for receiving a resonance voltage from the piezoelectric element via the other of the two divided electrodes and performing double-voltage full-wave rectification to generate a high voltage. 2. A disk-shaped piezoelectric vibrator, and the piezoelectric vibrator
A disk-shaped common electrode formed on one surface of the piezoelectric vibrator;
A semi-disc-shaped divided electrode formed on the other surface of the element and facing the common electrode, and is connected in series with an oscillating means and a capacitive element via one of the common electrode and the divided electrodes. A piezoelectric element constituting a resonance circuit; and a first voltage doubler which receives a resonance voltage from the piezoelectric element via one of the divided electrodes in accordance with the resonance of the series resonance circuit and performs full-wave voltage rectification and generates a high voltage. A high voltage generator comprising: a wave rectifying unit; and a second voltage doubler full wave rectifying unit that receives a resonance voltage from the piezoelectric element via the other divided electrode and performs double voltage full wave rectification to generate a high voltage. 3. A disk-shaped piezoelectric vibrator, and said piezoelectric vibrator
First and second arcuate plate-shaped divided electrodes formed on one surface
And third and fourth arc-shaped plates formed on the other surface of the piezoelectric vibrator.
And the first divided electrode includes a first divided electrode and a first divided electrode.
A second arc-shaped portion, wherein the fourth divided electrode is
3. The first arc-shaped portion, comprising a fourth arc-shaped portion
Is opposed to the third divided electrode, and the second arc-shaped portion
Is opposed to the third arc-shaped portion, and the second divided electrode
Is opposed to the fourth arc-shaped portion, and the first circle is
An arcuate portion, a portion of the piezoelectric vibrator facing the arcuate portion, and a front portion
A portion having the same function as the capacitive element in the third divided electrode
The third arc-shaped portion and the second arc-shaped portion.
The same as the oscillating means and the capacitive element via the arc-shaped portion
A piezoelectric element constituting a series resonant circuit together with the portion having the function, said from the piezoelectric element due to the resonance of the series resonant circuit first
A first voltage doubler full-wave rectifier that receives a resonance voltage via one split electrode and generates a doubled voltage full-wave rectification as a high voltage, and receives a resonance voltage from the piezoelectric element via the second split electrode. A second voltage doubler full-wave rectifier for generating a high voltage by performing voltage doubler full-wave rectification. 4. A central angle of said first divided electrode is 240 degrees.
The high voltage generator according to claim 3 , wherein a central angle of the second divided electrode is 120 degrees . 5. A central angle of said fourth divided electrode is 240 degrees.
The high voltage generator according to claim 3, wherein a central angle of the third divided electrode is 120 degrees .