JPH09238482A - Electrostatic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the insulating layers of a moving segment and a stator from being electrically charged. SOLUTION: A stator 22 wherein a plurality of electrodes 31a-31c are arranged on an insulating layer, and a moving segment 21 wherein a plurality of electrodes 27a-27c are arranged on an insulating layer 26 are installed. The moving segment 21 is arranged movably to the stator 22. When the moving segment 21 is driven, a voltage is applied to the electrodes by changing over the polarity at a period C constituted of a plurality of steps. The steps of each period is divided into the first half term (p) and the second half term (q). In the first half term of each step, a voltage is so applied that driving force is applied to the moving segment 21. In the second half term of each step, a voltage whose polarity is inverted to the voltage applied in the first half term is applied. When the moving segment 21 is stopped, voltages different in polarity are applied to the electrodes of the moving segment 21 and the electrodes of the stator 23 which face each other. The voltages are applied to the electrodes of the moving segments 21 and the stator 22 by alternating positive and negative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable as a drive source for a light-shielding device attached to a vehicle sun visor, a moon roof, a rear window, etc., a light-shielding device for a railway, an aircraft, a ship, etc., or a paper feeding device for a copying machine. It relates to an electrostatic actuator used. Specifically, each of the insulating layers is provided with a stator having a plurality of comb-teeth-shaped electrodes and a mover, and the mover is moved by electrostatic attraction or repulsion generated between the stator electrode and the mover electrode. In an electrostatic actuator to be driven, the present invention relates to prevention of electrification of a mover and a stator when the mover is driven and stopped.

[0002]

2. Description of the Related Art Conventionally, as this type of electrostatic actuator, the present applicant has previously proposed an electrostatic actuator shown in FIG. 18 in Japanese Utility Model Laid-Open No. 7-16599. The moving element 1 includes electrodes 3a, 3b, 3c ... 3a on the insulating layer 2,
3b, 3c ... Are arranged in a comb shape and these electrodes 3
The electrodes a, 3b, and 3c are connected to each other every other electrode to form three phases (a phase, b phase, and c phase), and the a phase electrode 3a and the b phase electrode 3b are connected to each other. And has two phases. On the other hand, the stator 4 has electrodes 6a, 6b,
6c ... 6a, 6b, 6c ... are provided in a comb shape, and electrodes 6a, 6b, 6c located at every two electrodes 6a, 6b, 6c are connected to each other to form three phases ( U phase, V
Phase, W phase).

When the mover 1 is driven, as shown in FIG. 19, the a-phase and b-phase electrodes 3a and 3b of the mover 1 are used.
In contrast, a negative (hereinafter referred to as "-") high voltage is
Positive for the c-phase electrode (hereinafter referred to as "+")
The high voltage is fixedly applied. On the other hand, the stator 4
, A high voltage having two types of polarities, “+” and “−”, having a rectangular waveform is periodically switched and applied. That is, the cycle C consisting of three consecutive steps S1, S2, S3 at equal time intervals α is repeated, and the cycle C of each phase is shifted by one step, and the electrodes 6a, 6b of the stator 4 are
A voltage is applied to 6c.

First, for the U-phase electrode 6a, the first step S1 is "+", the second step S2 is "-", and the third step is
In step S3, a high voltage is applied in a pattern of "+". Further, for the V-phase electrode 6b and the W-phase electrode 6c, one step or 2 steps more than the U-phase electrode 6a, respectively.
The voltage is applied by advancing the phase by the step. When a high voltage is applied in this way, an attractive force and a repulsive force due to electrostatic force act between the electrodes 3a to 3c of the mover 1 and the electrodes 6a to 6c of the stator 4, and the first step S1 to the third step At each step of S3, the mover 1 moves the electrodes 3a to
3c, 6a to 6c (inter-electrode pitch P)
Move to the left of 8.

[0005]

However, in this electrostatic actuator, in the next step of applying a voltage of "-" polarity to the electrodes 6a to 6c of each phase of the stator 4,
The voltage of the opposite polarity, that is, the voltage of the "+" polarity is applied, but the step of applying the voltage of the "+" polarity is continuous for two steps, and the switching of the voltage polarity is unbalanced.

In one cycle C, the voltage of "+" is applied for the time of 2 steps (2α), and the voltage of "-" is applied for 1 step. (Α), and the time for which the “+” voltage is applied per cycle C is one step longer than the time for which the “−” voltage is applied.

As described above, when the voltage polarities are unbalanced or the polarity of the voltage applied during one cycle is biased to "+" or "-", the insulating layer 5 of the stator 4 is "-"
Alternatively, there is a possibility that "+" charges may be charged. Insulating layer 5
When the high voltage is applied to the stator 4
The electrostatic force generated in the electrodes 6a to 6c of the above and the electrodes 3a to 3c of the mover 1 is reduced by the electric charge charged in the insulating layer 5, so that the driving force for the mover 1 is reduced or the mover 1 operates. However, there is a problem that the smoothness of the process decreases.

On the other hand, in the conventional electrostatic actuator as shown in FIG. 18, the voltage applied to the electrodes 3a to 3c and 6a to 6c of the moving element 1 and the stator 4 is stopped when the moving element 1 is stopped. By setting to “0” and pressing an external holding mechanism (not shown) against the mover 1, the mover 1
Was generally fixedly held on the stator 4.

However, in this case, the mover 1 against which the external holding mechanism is pressed may be deformed. Further, noise is generated when the external holding mechanism operates. Furthermore, it is not always easy to synchronize the operation of the electrostatic actuator and the external holding mechanism. Furthermore, a space for arranging the external holding mechanism is required, and a space (dead space) that cannot be used for arranging other devices is increased accordingly, and the electrostatic actuator control circuit becomes large and complicated. There is also the problem of turning into.

On the other hand, when the moving element 1 is stopped, the electrodes 3a to 3c, 6a to 6c of the moving element 1 and the stator 4 are fixed in polarity and a voltage is applied to the electrodes 3a to 3c of the moving element 1. A method of adsorbing the moving element 1 to the stator 4 and fixing and holding the moving element 1 by the attraction force due to static electricity generated between the electrode and the electrodes 6a to 6c of the stator 4 can be considered. In this case, although the holding force with respect to the moving element 1 is slightly reduced as compared with the case where the external holding mechanism is fixedly held, the external holding mechanism is not required, so that the operating noise, the dead space, and the control circuit are complicated. Problems such as complications are solved. Further, in this case, when the electrostatic actuator is applied to various light-shielding devices or the like and commercialized, the entire device is simplified and downsized.

However, if the polarities are fixed to the electrodes 3a to 3c and 6a to 6c of the moving element 1 and the stator 4 and the electrodes are left with a voltage applied, the electrodes 3 of the moving element 1 and the stator 4 are left.
A phenomenon occurs in which the electrode charges of a to 3c and 6a to 6c are saturated and charged in the insulating layers 2 and 5. In this way, when the insulating layers 2 and 5 of the moving element 1 and the stator 4 are still charged, the driving force of the moving element 1 is hindered by the attraction force due to the charges charged on the insulating layers 2 and 5 when the driving is restarted. Therefore, the mover 1 normally
When the insulating layers 2 and 5 are strongly charged, the mover 1 cannot be moved.

The present invention solves the above problems in the conventional electrostatic actuator, and prevents the charging of the stator without lowering the driving force for the moving element and without performing complicated control. It was done for the purpose. Another object of the present invention is to prevent electrification of the stator and the moving element when the moving element is stopped so that the moving element can move smoothly when re-driving.

[0013]

Therefore, according to a first aspect of the present invention, a stator having a plurality of electrodes arranged on an insulating layer and a plurality of electrodes arranged on the insulating layer are arranged so as to be movable with respect to the stator. An electrostatic actuator that drives the mover by applying a voltage to the stator and the electrode of the mover, and by a suction force and a repulsive force generated between the electrode of the mover and the electrode of the stator. Therefore, when driving the mover, the polarity of the mover and the electrodes of the stator is switched in a cycle consisting of a plurality of steps to apply a voltage, and each step of each cycle is divided into a first half period and a second half period, In the first half of each step, a voltage is applied to the electrodes of the mover and the stator so that the driving force acts on the mover, while in the second half of each step, the voltage and polarity applied in the first half are changed. It is characterized by being configured to apply an inverted voltage There is provided an electrostatic actuator.

According to a first aspect of the present invention, each step of each cycle is divided into the first half and the second half when the moving element is driven, and the moving element and the fixing element are fixed so that the driving force acts on the moving element in the first half term. When the voltage is applied to the electrodes of the child while the voltage is applied in the latter half of the period by reversing the polarity from the first half of the period, the insulating layers of the moving element and the stator are not charged during driving of the moving element. Can be prevented.

According to a second aspect of the present invention, there is provided a stator having a plurality of electrodes arranged on the insulating layer, and a mover having a plurality of electrodes arranged on the insulating layer and movably arranged with respect to the stator. An electrostatic actuator for driving a mover by applying a voltage to the electrode of the stator and the electrode of the mover, and by the attractive force and repulsive force generated between the electrode of the mover and the electrode of the stator. At the time of stopping, voltage of different polarity is applied to the electrode of the moving element and the electrode of the stator which are opposed to each other, and the voltage is applied by alternately switching positive and negative to each electrode of the moving element and the stator. The present invention provides an electrostatic actuator, characterized in that a voltage is applied to electrodes of a stator and a stator by switching polarities in a cycle including a plurality of steps.

According to a second aspect of the present invention, when the mover is stopped, voltages of different polarities are applied to the electrodes of the mover and the electrodes of the stator which are opposed to each other, and the electrodes of the mover and the stator are applied to each other. In the case where the voltage is applied by alternately switching positive and negative, the moving element is held by the attraction force generated between the electrode of the moving element and the electrode of the stator. Further, since the voltages applied to the electrodes of the mover and the stator are not biased, it is possible to prevent the insulating layers of the mover and the stator from being charged.

When the moving element is stopped, a step of connecting the electrode to the ground may be provided before switching the polarity of the voltage applied to each electrode of the moving element and the stator. (Claim 3) When the step of connecting to the ground is provided in this manner, it is possible to prevent the occurrence of so-called ripple noise that causes a malfunction.

In the electrostatic actuator according to the present invention, the electrodes of the moving element are connected to each other and the electrodes of the moving element are connected to each other to form three phases. The electrodes may be connected to each other to form three phases (Claim 4), or the electrodes of the moving element may be connected to each other to form two phases. At the same time, two electrodes of the stator may be connected to each other to form two phases.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail based on the embodiments shown in the drawings. 1 and 2
FIG. 4 shows an electrostatic actuator according to the first embodiment of the present invention. This electrostatic actuator includes a moving element 21,
A stator 22, a control means 23, an operation switch 24 and a high voltage source 25 are provided.

The mover 21 is held so as to be movable in parallel with the stator 22, and as shown in FIG. 2A, a plate-like insulating layer 26 made of a dielectric material such as polyethylene terephthalate (PET). A plurality of elongated rectangular electrodes 27a, 27b made of a conductive metal on one surface
27c ... 27a, 27b, 27c ... are provided in a comb shape. These electrodes 27a to 27c are connected to each other at every two electrodes 27a to 27c. Of these, the electrode 27 a is the electrode 27 a of the insulating layer 26.
Power supply unit 2 provided on one side of the surface on which 27c is provided
It is connected to 8A and constitutes the a phase. Further, the electrode 27b is connected to the power feeding portion 28B provided on the other side of the surface of the insulating layer 26 on which the electrodes 27a to 27c are provided, and constitutes the b-phase. Further, the electrode 27c includes a conductive member 29 arranged in a through hole (through hole 26a) provided in the insulating layer 26 in a power feeding portion 28C provided in a surface of the insulating layer 26 opposite to the surface provided with the electrodes 27a to 27c. They are connected to each other and form a c-phase.

Electrodes 27a to 27 of each phase of the mover 21
c has its width d1 set to be equal. In addition, electrode 2
The intervals (electrode pitch P1) between 7a to 27c are also set to be equal.

Among the electrodes 27a to 27c of the mover 21, the a-phase electrode 27a is connected to the relay R1 from the power feeding portion 28A.
Is connected to the "+" side of the high voltage source 25 via the relay R4, connected to the "-" side of the high voltage source 25 via the relay R4, and further connected to the ground 35 (potential is "0" via the relay R7).
It is. ) Is connected to. Similarly, the b-phase electrode 27b of the mover 21 is connected to the relays R2, R from the power feeding unit 28B.
5, R8 through the high voltage source 25 "+" side,
It is connected to the “−” side and the ground 35. In addition, the c-phase electrode 27c of the mover 21 is also
High voltage source 25 through relays R3, R6 and R9 respectively
Are connected to the “+” side, the “−” side, and the ground 35. These relays R1 to R9 are opened and closed in response to a command from the control means 23, and are connected to the electrodes 27a to 27c of the mover 21,
The "-" side and "+" side of the high voltage source 25 or the ground 35 are connected and disconnected.

The stator 22 is, as shown in FIG.
A plurality of elongated rectangular electrodes 31a, 31b, 31c ... 31a, 31b made of conductive metal are formed on one surface of the plate-shaped insulating layer 30 made of a dielectric material such as PET.
31c ... is provided. These electrodes 31a-31
The electrodes c are connected to each other at every two electrodes 31a to 31c. Of these, the electrode 31a is connected to the power feeding portion 32A provided on one side of the surface of the insulating layer 30 on which the electrodes 31a to 31c are provided, and constitutes the U phase.
The electrodes 31b are the electrodes 31a to 31c of the insulating layer 30.
Is connected to a power feeding portion 32B provided on the other side of the surface on which the power supply is provided, and forms a V phase. Further, the electrode 31
c is connected to the power feeding portion 32C provided on the surface opposite to the surface of the insulating layer 30 on which the electrodes 31a to 31c are provided via the conductive member 33 arranged in the through hole 30a provided in the insulating layer 30, It forms the W phase.

Electrodes 31a to 31 of each phase of the stator 22
c has its width d2 set equal, and this width d2
Is the width d of the electrodes 27a to 27c of each phase of the mover 21.
Equal to 1. The electrode pitch P2 between the electrodes 31a to 31c is also uniform, and the electrode pitch P2 is equal to the electrode pitch P1 of the mover 21.

Among the electrodes 31a to 31c of the stator 22, the U-phase electrode 31a is connected to the relay R1 from the power feeding portion 32A.
While connected to the "+" side of the high voltage source 25 via 1,
It is connected to the “−” side of the high voltage source 25 via the relay R14, and further connected to the ground 35 via the relay R17. Similarly, the V-phase electrode 31b of the stator 22
From the power feeding unit 32B to the relays R12, R15, R18.
Are connected to the “+” side, the “−” side of the high voltage source 25 and the ground 35, respectively. In addition, the stator 22
The W-phase electrode 31c of the relay R1
3, the relays R16 and R19 are connected to the "+" and "-" sides of the high voltage source 25 and the ground 35, respectively. The relays R11 to R19 connect and disconnect the electrodes 31a to 31c of the stator 22 and the “−” side, “+” side of the high voltage source 25 or the ground 35 in accordance with a command from the control means 23. .

The control means 23 includes the relays R1 to R19.
Are switched as follows to change the polarity of the voltage applied to the electrodes 27a to 27c and 31a to 31c of the mover 21 and the stator 22.

First, when a high voltage of "+" is applied to the electrodes 27a to 27c of the mover 21, the control means 23 connects the relays R1 to R3, and at the same time, the relays R4 to R9.
Cut off. Further, when a high voltage of "-" is applied to the electrodes 27a to 27c of the mover 21, the control means 23 causes the relays R4 to R6 to communicate with each other and the relays R1 to R3.
Also, the relays R7 to R9 are cut off. Furthermore, the mover 21
When the potentials of the electrodes 27a to 27c of No. 1 are set to "0", the relays R7 to R9 are connected and the relays R1 to R6 are connected.
Cut off.

Similarly, the electrodes 31a to 31c of the stator 22 are
When a high voltage of "+" is applied to the relay R1, the control means 23 connects the relays R11 to R13 and the relay R1.
Shut off 4-R19. In addition, the electrode 31 a of the stator 22
When a high voltage of "-" is applied to ~ 31c, the control means 23 connects the relays R14 to R16 and disconnects the relays R11 to R13 and the relays R17 to R19. Further, when the potentials of the electrodes 31a to 31c of the stator 22 are set to "0", the relays R17 to R19 are connected and the relays R11 to R16 are cut off.

Next, the operation of the first embodiment will be described. In this electrostatic actuator, the controller 23 controls the relays R1 to R19 according to the setting of the operation switch 24.
By opening and closing, the polarities are switched to the electrodes 27a to 27c and 31a to 31c of the mover 21 and the stator 22, and a high voltage is applied.

[0030] In FIG. 3, up to and time t ₁₃ after time t _6, the operation switch 24 is set to "Stop". In addition, in the present embodiment, when the moving element 21 is stopped, as shown in FIG.
As shown in (A) to (C), an a-phase electrode 27a and a V-phase electrode 31b, a b-phase electrode 27b and a W-phase electrode 31c,
Further, the c-phase electrode 27c and the U-phase electrode 31a face each other.

While the moving element 21 is stopped, the electrode 27 is
a to 27c and 31a to 31c, a voltage is applied to mover 2
No. 1 electrode 27a-27c and the stator 22 electrode 31a-3
The moving element 21 is attracted to the stator 22 and fixedly held in a stopped state by the attraction force due to static electricity between the moving element 21 and the fixed electrodes 1a to 27c and 31a to 31c. Insulation layers 26, 30 of the child 22
Do not charge.

Specifically, during the stop period of the moving element 21, a minute time period C'is repeated to apply a voltage to the electrodes 27a to 27c and 31a to 31c of the moving element 21 and the stator 22. . This cycle C ′ includes a first suction step S1 ′, a first ground connection step S2 ′, a second suction step S3 ′, and a second ground connection step S.
It consists of 4 '. The first and second adsorption steps S
1 ′ and S3 ′ have the same duration, and the first and second
The durations of the ground connection steps S2 'and S4' are also the same.

The first adsorption step S1 '(in FIG. 3,
From time t ₁ to time t ₂ ), as shown in FIG.
A voltage of "-" is applied to the a-phase electrode 27a of the mover 21, and a voltage of "+" polarity is applied to the V-phase electrode 31b of the stator 22 facing the a-phase electrode 27a. Apply. Further, a voltage of "+" is applied to the b-phase electrode 27b of the mover 21, and the W of the stator 22 facing this is applied.
A "-" voltage is applied to the phase electrode 31c. Further, the c-phase electrode 27a of the mover 21 and the U-phase electrode 31a of the stator 22 that faces the c-phase electrode 27a are connected to the ground 35 so that the potential becomes “0”. Therefore, the first adsorption step S
Between 1 ', between the a-phase electrode 27a of the mover 21 and the V-phase electrode 31b due to static electricity, and between the b-phase electrode 27b of the mover 21 and the W-phase electrode 31c. The moving element 21 is attracted to the stator 22 by the attraction force of static electricity, and is fixedly held in a stopped state.

The 'first ground connection step S2 following the' (time t ₃ from in FIG time t ₂₎ of the first adsorption step S1, and the first ground connection step S
As shown in FIG. 4B, 2 ′ connects all the a-phase to c-phase electrodes 27 a to 27 c of the mover 21 and the U-phase to W-phase electrodes 31 a to 31 c of the stator 22 to the ground 35. To the potential "0".

[0035] a 'following the second adsorption step S3' first ground connection step S2 (time t ₄ from in FIG time t _3). In the second adsorption step S3 ', a voltage is applied to the electrodes 27a to 27c and 31a to 31c of the mover 21 and the stator 22 with a polarity opposite to that of the first adsorption step S1'. That is, as shown in FIG. 4C, a "+" voltage is applied to the a-phase electrode 27a of the mover 21, and a "-" voltage is applied to the V-phase electrode 31b facing the a-phase electrode 27a. In addition, a “−” voltage is applied to the b-phase electrode 27b of the mover 21, and the W-phase electrode 31 opposite to this is applied.
A high voltage of "+" is applied to c. In addition, the c-phase electrode 2
7c and the U-phase electrode 31a are connected to the ground 35.
In the second adsorption step S3 ′, similarly to the first adsorption step S1 ′, between the a-phase electrode 27a and the V-phase electrode 31b and between the b-phase electrode 27b and the W-phase electrode 31c.
The electrostatic attraction force is generated between the moving element 21 and the moving element 21 and the moving element 21 is attracted to the stator 22 by this attractive force and is fixedly held in a stopped state.

Following the second adsorption step S3 ', a second
This is the ground connection step S4 '(at time t _{4 in} FIG. 3).
From time t ₅ ), as shown in FIG.
And the electrodes 27a to 27c and 31a to 31c of the stator 22.
Are all connected to the ground 35 so that the potential is "0".

As described above, in the first embodiment, each cycle C'is
In the first and second adsorption steps S1 ′ and S3 ′, the a-phase electrode 27a of the mover 21 and the V-phase electrode 3 of the stator 22 are
1b and the attracting force generated between the b-phase electrode 27b of the mover 21 and the W-phase electrode 31c of the stator 22 cause the mover 21 to be attracted to the stator 22 and thus move. The child 21 can be fixedly held with respect to the stator 22 in a stopped state. Therefore, in the electrostatic actuator of the first embodiment, it is not necessary to provide the external holding mechanism for fixing and holding the moving element described above.

In addition, as described above, the a-phase electrodes 27a, 27b
Phase electrode 27b, V phase electrode 31b and W phase electrode 31
The voltage applied to c is the first adsorption step S
Since the polarities are set to be reversed in 1 ′ and the second adsorption step S3 ′, and the durations of the first adsorption step S1 ′ and the second adsorption step S3 ′ are equal, within one cycle C ′ In addition, the sum of the voltages applied to the mover 21 and the stator 22 is "0". Therefore, in the first embodiment, the insulating layers 26, 30 can be prevented from being charged by applying a voltage to the electrodes 27a, 27b, 31b, 31c.

Further, in the first embodiment, the a-phase and b-phase electrodes 27a and 27b of the mover 21 and the V of the stator 22 are arranged.
Adsorption step S of applying a voltage of "+" or "-" polarity to the electrodes 31b and 31c of the W-phase and W-phase
Since the first ground connection step S2 'or the second ground connection step S4' exists between 1'and the second adsorption step S3 ', the a-phase and b-phase electrodes 27 are used.
a, 27b and the electrodes 27a, 27b before switching the polarities of the voltages applied to the V-phase and W-phase electrodes 31b, 31c.
b, 31a and 31b are once connected to the ground 35. Therefore, these electrodes 27a, 27b, 31a, 3
Switching of the voltage applied to 1b is not instantaneous and rapid, and so-called ripple noise that causes a malfunction can be prevented.

Furthermore, all the electrodes 27a-27
By providing the first and second ground connection steps S2 'and S4' for setting the potentials c, 31a to 31c to "0", the first and second adsorption steps S1 ', S1',
By reversing the polarity of the voltage applied in S3 ′, the efficiency of removing the charges of the a-phase and b-phase electrodes 27a and 27b and the V-phase and W-phase electrodes 31b and 31c is improved.

In the first embodiment, the duration of the first and second adsorption steps S1 'and S3' and the first and second
The ratio to the duration of the ground connection steps S2 'and S2' of 5 is set to 5: 1. The ratio between the duration of the first and second adsorption steps S1 ′ and S3 ′ and the first and second ground connection steps S2 ′ and S4 ′ is such that the electrode pitches P1 and P2 are 0.4 to 0. 6 mm, electrode width d
1, d2 is 0.2 to 0.3 mm, the insulating layers 26 and 30 of the moving element 21 and the stator 22 are made of polyethylene terephthalate and have a width of 0.2 to 0.3 mm, and are applied to the electrodes of the moving element and the stator. Voltage is ± 700V, and the cycle C'is 15
In the case of ˜30 Hz (0.03 to 0.06 s), (duration of the first and second adsorption steps S1 ′, S3 ′): (first and second ground connection periods S2 ′, S)
It is preferable to set 4 ′) = 5: 1, and the ratio is also set in the first embodiment as described above. However,
The duration of the first and second ground connection steps S2 ′ and S4 ′ is determined by the electrode widths d1 and d2 and the electrode pitch P.
1, P2, etc., and the first and second adsorption steps S
It is preferable to set it so that the charges applied to the electrodes in 1'and S3 'can be sufficiently removed.

[0042] In FIG. 3, while from time t ₆ to time t _13, the operation switch 24 is set to "move to the left".
When the moving element 21 is driven, the electrodes 27a to 27c of the respective phases of the moving element 21 and the electrodes 31a of the respective phases of the stator 22 are driven.
The voltage is applied by periodically switching the polarities with respect to .about.31c. The cycle C of switching the polarity of the voltage applied to the mover 21 and the stator 22 is composed of first to third steps S1, S2 and S3 having the same time interval.

In the present embodiment, the voltage is applied by dividing the first to third steps S1 to S3 constituting one cycle C into the first half period p and the second half period q at equal time intervals. The voltage applied to the first-half period p in each of steps S1 to S3 has the same polarity as that of the conventional electrostatic actuator shown in FIGS. 18 and 19, and as will be described later, the voltage applied to the first-half period p. As a result, a driving force acts on the mover 21.
The voltage applied in the latter half q is applied to prevent the insulating layers 26 and 30 from being charged, and the polarity is inverted with respect to the voltage applied in the first half p and the voltage is applied.

The a-phase electrode 27a of the mover 21 has a first
The voltage of "-" polarity is applied in the first half period p of step S1, and the polarity is inverted and the voltage of "+" polarity is applied in the second half period q of the first step S1. Second step S2
Also in the third step S3, as in the first step S1, a voltage of "-" is applied to the first half period p and a voltage of "+" is applied to the second half period q. In addition, in the b-phase electrode 27b of the mover 21,
A voltage is applied with the same waveform as that of the a-phase electrode 27a. Furthermore, the c-phase electrode 27c of the mover 21 has a first to a third electrode 27c.
In the first half p of steps S1 to S3, the voltage of the “+” polarity is applied and the first to third steps S1 to S3 are performed.
In the latter half q of S3, the polarity is reversed and a high voltage of "-" is applied. The application of voltage to the a-phase, b-phase, and c-phase electrodes 27a to 27c of the mover 21 is performed at each step S1 in the voltage waveform applied to the mover of the conventional electrostatic actuator shown in FIGS. The polarity is inverted in the latter half q of S3.

In the first embodiment, since the voltage is applied to the mover 21 with such a waveform, the step S1 is performed for each of the a-phase to c-phase electrodes 27a to 27c of the mover 21. , S2, S3, the sum of the voltages applied is “0”, and the sum of the voltages applied within one cycle C is also “0”. Therefore, the electrode 2 of the mover 21
It is possible to prevent the insulating layer 26 from being charged by applying a voltage to 7a to 27c.

During the moving period of the moving element 21, a voltage having the same waveform is applied to the U-phase, V-phase and W-phase electrodes 31a to 31c of the stator 22, and is applied to the V-phase. The voltage advances the phase by 1 step (1/3 · C) with respect to the U phase, and the voltage applied to the W phase has a phase by 2 steps (2/3 · C) with respect to the U phase. We are promoting.

A voltage is applied to the U-phase electrode 31a as follows. First, the first step S1
The voltage of "+" is applied to the first half p of the second step S2, the voltage of "+" is applied to the first half of the second step S2, and the voltage of "-" is applied to the first half p of the third step S3. The polarities of the voltages applied in the first half p of each of these steps S1 to S3 are the same as those of the first to third steps for the electrodes of the stator 2 in the conventional electrostatic actuator shown in FIGS. It is the same as the polarity of the voltage applied to S1 to S3.

On the other hand, the first to third steps S1 to S3
In the second half q of the above, a voltage whose polarity is inverted from the voltage applied in the first half p is applied. That is, for the U-phase 31a, "-" is shown in the latter half q of the first step S1, "-" is shown in the latter half q of the second step S2, and "-" is shown in the latter half q of the third step S3. + ”Voltage is applied.

As described above, the voltage is applied to the V-phase electrode 31b by advancing the phase by one step with respect to the U-phase electrode 31a, and the voltage is applied in the first to third steps S1 to S3.
In the first half p of 1 to S3, "+", "-",
The voltage of "+" is applied, and the first to third steps S1 to S1.
In the latter half q of S3, the polarities of the voltages are inverted and the voltages of "-", "+", and "-" are applied, respectively.

As described above, the voltage is applied to the W-phase electrode 31c by advancing the phase by two steps with respect to the U-phase electrode 31a.
In the first half p of 1 to S3, "-", "+",
By applying a voltage of "+", the first to third steps S1 to S
In the latter half q of 3, the voltage polarity is reversed and the voltages of "+", "-", and "-" are applied.

As described above, in the first embodiment, the stator 22
In the U-phase to W-phase electrodes 31a to 31c, a voltage having a polarity opposite to that of the voltage applied in the first half period p of the first to third steps S1 to S3 is applied in the second half period q.
The sum of the voltages applied to the U-phase to W-phase electrodes 31a to 31c every 1 to S3 is "0". Therefore, the stator 22
The insulating layer 30 can be prevented from being charged by the voltage applied to the electrodes 31a to 31c of each phase.

Next, FIGS. 5A to 5E and 6A.
With reference to (D) to (D), the movement of the moving element 21 in the one cycle C will be described. As described above, when the mover 21 is stopped, the a-phase electrode 27a and the V-phase electrode 31b, the b-phase electrode 27b and the W-phase electrode 31b, and the c-phase electrode 27c and U are connected. Since the phase electrodes 31a are facing each other, the positional relationship between the mover 21 and the stator 22 is assumed to be in this state when the operation switch 24 is set to "move".

As shown in FIG. 5 (A), during the first half period p of the first step S1 (from time t ₆ to time t _{7 in} FIG. 3), the a-phase and b-phase electrodes 27a, A high voltage of "-" is applied to 27b and a high voltage of "+" is applied to the c-phase electrode 27c. Further, the U-phase and V-phase electrodes 31a, 3 of the stator 22
A voltage of "+" is applied to 1b, and a voltage of "-" is applied to the W-phase electrode 31c. Therefore, as shown by an arrow in FIG. 5A, electrostatic attraction force and repulsive force act between the electrodes 27 a to 27 c of the moving element 21 and the electrodes 31 a to 31 c of the stator 22 to move the moving element 21. A driving force for moving to the left side in the figure is generated. Note that in FIGS. 5 and 6, the electrodes 27a to 27 are formed.
Of the arrows shown between c and 31a to 31c, the downward arrow indicates the force (suction force) that attracts the moving element 21 toward the stator 22, and the upward arrow indicates the force that separates the moving element 2 from the stator 22. (Repulsive force) is shown.

FIG. 5B shows a time point (time t _{7 in} FIG. 3) at which the first half p of the first step S1 ends, and at this time point, it occurs between the electrodes 27a to 27c and 31a to 31c. Due to the attractive force and the repulsive force, the mover 21 is moved to the left by exactly one pitch from the state shown in FIG. 5 (A). That is, the a-phase, b-phase, and c-phase electrodes 27a, 27b, and 27c of the mover 21 are respectively attached to the stator 2
The two U-phase, V-phase, and W-phase electrodes 31a, 31b, and 31c are opposed to each other.

FIG. 5C shows the latter half q of the first step S1 (from time t ₇ to time t _{8 in} FIG. 3). In the latter half q, the polarities of the voltages applied to the electrodes 27a to 27c and 31a to 31c are reversed. That is, “+”, “+”, and
A "-" voltage is applied to the U-phase to W-phase electrodes 31a to 31c of the stator 22 to indicate "-", "-", and "+", respectively.
Is applied. As shown in FIG. 5 (C), in the latter half q of the first step S1, the electrode 27 of the mover 21 is
a to 27c and the electrodes 31a to 31c of the stator 22 act on the electrodes 27a to 27c, 3 facing each other.
Since the suction force acting between 1a to 31c is the largest, the driving force for moving the mover 21 to the left hardly acts.

By applying a voltage having a polarity opposite to the voltage applied in the first half period p to the electrodes 27a to 27c and 31a to 31c of the mover 21 and the stator 22 in the second half period q, the first step is performed. Since the sum of the voltages applied to the electrodes 27a to 27c and 31a to 31c of the mover 21 and the stator 22 during S1 is "0", the insulating layers 26 and 30 of the mover 21 and the stator 22 are It is possible to prevent charging.

FIG. 5D shows the first half p of the second step S2 (from time t ₈ to time t _{9 in} FIG. 3). In the first half period p of the second step S2, “-” is applied to the electrodes 27a to 27c of the a-phase to the c-phase of the mover 21, respectively.
High voltages of "-" and "+" are applied. Also, the stator 2
“+” Is applied to the U-phase to W-phase electrodes 31a to 31c of FIG.
Voltages of "-" and "+" are applied. Therefore, FIG.
As shown by the arrow in (D), the electrode 27a of the mover 21 is shown.
~ 27c and the electrodes 31a to 31c of the stator 22 are attracted and repulsed by static electricity, and a driving force for moving the mover 21 to the left side in the drawing is applied.

FIG. 5 (E) shows the time point (time t _{9 in} FIG. 3) at which the first half p of the first step S1 ends, and the mover 21 moves one pitch to the left, 21 a
Phase electrode 27a and the W-phase electrode 31c of the stator 22 face each other, the b-phase electrode 27b of the mover 21 and the U-phase electrode 31a of the stator 22 face each other, and
The phase electrode 27c and the V-phase electrode 31b of the stator 22 face each other.

FIG. 6A shows the second half q of the second step S2 (from time t ₉ to time t _{10 in} FIG. 3). The polarities of the voltages applied to the electrodes 27a to 27c and 31a to 31c in the latter half period q are inverted with respect to the voltages applied in the first half period p, and the a-phase to c-phase electrodes 27a of the mover 21 are used. Voltages of "+", "+", and "-" are applied to the electrodes 27a to 27c, respectively.
Voltages of "-", "+", and "-" are applied to ~ 31c, respectively. Therefore, during the second step S2, each electrode 2
The sum of the voltages applied to 7a to 27c and 31a to 31c is “0”, and the insulating layer 2 of the moving element 21 and the stator 22 is
It is possible to prevent the charging of 6, 30.

FIG. 6B shows the first half p of the third step S3 (from time t ₁₀ to time t _{11 in} FIG. 3).
High voltages of "-", "-", and "+" are applied to the a-phase to c-phase electrodes 27a to 27c, respectively. Also,
In the U-phase to W-phase electrodes 31a to 31c of the stator 22,
Voltages of "-", "+", and "+" are applied respectively.
Therefore, the electrodes 27a to 27c of the mover 21 and the stator 22 are
Between the electrodes 31a to 31c of the
The driving force to the left in the figure acts on.

FIG. 6C shows the time point (time t _{11 in} FIG. 3) at which the first half p of the third step S3 ends.
At this point, the mover 21 has moved one pitch further to the left. That is, the a-phase electrode 27 of the mover 21
a and the V-phase electrode 31b of the stator 22 face each other,
1 b-phase electrode 27b and the stator 22 W-phase electrode 31c
Are opposed to each other, and further, the c-phase electrode 27 of the mover 21 is
c and the U-phase electrode 31a of the stator 22 face each other.

FIG. 6D shows the latter half q of the third step.
(Time t ₁₁ to time t _{12 in} FIG. 3) is shown, and the latter half q
In the first half p of the third step S3, the electrode 27
a-27c and 31a-31c, the polarity of the voltage applied is reversed, and the a-phase to the c-phase electrodes 27a-27 of the mover 21 are reversed.
Voltages of “+”, “+”, and “−” are applied to each of c, and the U-phase to W-phase electrodes 31a to 31c of the stator 22 are
Voltages of "+", "-" and "-" are applied. Therefore, during the third step S3, the electrodes 27a to 27c and 31a to 27a to 27c.
The sum of the voltages applied to 31c is "0", and the insulating layers 26 and 30 of the moving element 21 and the stator 22 can be prevented from being charged.

As described above, in the electrostatic actuator according to the first embodiment, each step S of one cycle C is performed during driving.
1 to S3 are divided into a first half period p and a second half period q, and in the first half period p, the moving element 2 is moved so that the driving force acts on the moving element 21.
1 and electrodes 27a to 27c, 31a to 31 of the stator 22
While a voltage is applied to c, in the second half q of each of steps S1 to S3, the voltage is applied with the polarity reversed from that in the first half p, so that the insulating layers 26 of the mover 21 and the stator 22 are
It is possible to prevent the charging of 30. In addition, in the present embodiment, the electrodes 27 a to 27 c of the mover 21 and the stator 22.
On the other hand, since the sum of the voltages applied during one cycle C is also “0”, this also prevents the insulating layers 26 and 30 of the moving element 21 and the stator 22 from being charged.

As described above, in the first embodiment, the mover 21
Since it is possible to prevent the insulating layers 26 and 30 of the moving element 21 and the stator 22 from being charged by applying a voltage to the electrodes 27a to 27c and 31a to 31c during the driving of By the electrode 27a of the mover 21
.About.27c and the electrodes 31a to 31c of the stator 22 are reduced, it is possible to prevent the driving force of the moving element 21 from decreasing.

The operation switch 14 is "moved to the right".
Is set to, the electrodes 31a, 31a of the stator 22 are
b and 31c have the same pattern and V-phase electrode 3
It suffices to delay the phases of the 1b and W-phase electrodes 31c from the U-phase electrode 31a by 2 steps and 4 steps, respectively, and switch the polarities to apply a voltage.

7 and 8 show a second embodiment of the present invention. In the second embodiment, the structure of the mover 21, the stator 22 and the like, and the electrode 27a when the mover 21 is driven.
~ 27c, 31a ~ 31c The waveform of the applied voltage is the first
Similar to the embodiment, the voltage applied to the moving element 21 and the stator 22 when the moving element 21 is stopped is different.

That is, in the second embodiment, as shown in FIG. 7, the a-phase and b-phase electrodes 27a, 27 of the mover 21 are used.
b, voltage is applied to the V-phase and W-phase electrodes 31b and 31c of the stator 22 in the same waveform as in the first embodiment,
At the same time, a voltage is applied to the c-phase electrode 27c of the mover 21 and the U-phase electrode 31a of the stator 22. In the first adsorption step S1 ′ of each cycle C ′, as shown in FIG. 8A, a “+” voltage is applied to the c-phase electrode 27c and a “−” voltage is applied to the U-phase electrode 31a. Apply. In the first ground connection step S2 ′, as shown in FIG. 8B, the potential applied to the c-phase electrode 27c and the U-phase electrode 31c is set to “0”. In the second adsorption step S2 ',
As shown in FIG. 8C, a voltage of "-" is applied to the c-phase electrode 27c and a voltage of "+" is applied to the U-phase electrode 31a. In addition, in the second ground connection step S4 ',
As shown in FIG. 8D, the c-phase electrode 27c and the W-phase electrode 31c are connected to the ground 35 to have a potential "0".

In the second embodiment, the first of each cycle C'is
And in the second adsorption steps S1 ′ and S3 ′, the mover 2
1 because the moving member 21 is fixed and held by the attraction force acting between the electrodes 27a to 27c of all the phases a to c and the electrodes 31a to 31c of the stator 22 of all the phases U to W. The holding force of the mover 21 is about 1.5 times that of the first embodiment.

9 and 10 show a third embodiment of the present invention. In the third embodiment, the electrodes 27a, 27b, ... Of the mover 21 have two phases, and the electrodes 31a, 31b ... Of the stator 22 also have two phases.

As shown in FIG. 10A, the mover 21 is made of a conductive metal on one surface of a plate-like insulating layer 26 made of a dielectric material such as PET and has a plurality of elongated rectangular shapes. 27a, 27b, ... 27a, 27b
・ ・ Is provided. These electrodes 27a and 27b are connected to the power supply parts 28A and 28B provided on both sides of the insulating layer 26 for every other electrode 27a and 27b, and the electrodes 27a and 27b connected to one power supply part 28A are 27a ...
, Constitute the a phase, and the electrodes 27b, 27b, ... Connected to the other power feeding portion 28B constitute the b phase.

Electrodes 27a, 27 of each phase of the mover 21
In b, the width d1 and the electrode pitch P3 are set to be equal to each other, and an arbitrary electrode 27a of the a-phase electrodes 27a,
The b-phase electrode 2 adjacent to the right side of this electrode 27a in FIG.
Let L1 be the distance between 7b and L2 be the distance between the arbitrary electrode 27b of the b-phase electrodes 27b and the a-phase electrode 27a adjacent to the right side of this electrode 27b in FIG. 1, L1: L2 is 1: It is 1.

The a-phase electrode 27a of the mover 21 is connected to the "+" side, the "-" side and the ground 35 of the high voltage source 25 through the relays R31, R33 and R35 from the power feeding section 28A. . Also, the b-phase electrode 2 of the mover 21
7b is a relay R32, R34, R3 from the power supply unit 28B.
6 are connected to the “+” side, the “−” side of the high voltage source 25 and the ground 35, respectively.

As shown in FIG. 10B, the stator 22 is made of a conductive metal on one surface of a plate-shaped insulating layer 30 made of a dielectric material such as PET and has a plurality of elongated rectangular shapes. 31a, 31b ... 31a, 31b ...
・ It is provided. These electrodes 31a and 31b are connected to the power feeding portions 32A and 32B provided on both sides of the insulating layer 30 for every other electrode 31a and 31b, and the electrodes 31a and 31a connected to one power feeding portion 32A. .. constitute the U phase, and the electrode 31 connected to the other power feeding portion 32B
b, 31b ... Form the V phase.

Electrodes 31a, 31 of each phase of the stator 22
The width b2 of b is set to be equal, and the width d2 is equal to the width d1 of the electrodes 27a and 27b of each phase of the mover 21. The electrode pitch of the stator 22 is nonuniform. That is, the distance between the arbitrary electrode 31a of the U-phase electrodes 31a and the V-phase electrode 31b adjacent to the right side of this electrode 31a in FIG. 9 is L3, and the arbitrary electrode 31b of the V-phase electrodes 31b is If the distance between the U-phase electrodes 31a adjacent to the right side of FIG. 9 of this electrode 31b is L4, L3:
L4 is set to 1: 3.

The U-phase electrode 31a of the stator 22 is fed from the power feeding portion 32A through the relays R41, R43, R45 to the "+" side of the high voltage source 25 and the ground 3 respectively.
5 is connected. In addition, the V-phase electrode 31 of the stator 22
b is a relay R42, R44, R46 from the power feeding unit 32B.
Are connected to the "+" side and "-" side of the high voltage source 25 and the ground 35, respectively.

In the electrostatic actuator of the third embodiment, the electrodes 27 of the mover 21 and the stator 22 are used as described above.
Since a, 27b, 31a, and 31b are both two-phase, there is no need to provide through holes or conductive members in either the mover 21 or the stator 22, and the relay R
The number of 31 to R36 and R41 to R46 can be reduced.

As in the case of the first embodiment, the control means 23 connects / disconnects the relays R31 to R36 and R41 to R46 in accordance with the setting of the control switch 24, so that the mover 21 and the fixed member are fixed. The electrode 27a of the child 22,
The voltage applied to 27b, 31a, 31b is switched.
The other structure of the electrostatic actuator according to the third embodiment is the same as that of the first embodiment, and in FIG. 9, the same elements as those of the first embodiment are designated by the same reference numerals.

Next, the operation of the third embodiment will be described. In FIG. 11, the operation switch 24 is set to “stop” until time t ₆ and after time t ₂₃ . FIG.
As shown in FIGS. 2 (A) to 2 (D), the positional relationship between the moving element 21 and the stator 22 when the moving element 21 is stopped is as follows.
The phase-phase electrode 27a and the U-phase electrode 31a of the stator 22 face each other, and the a-phase electrode 27a and the b-phase electrode 27b of the mover 21
The V-phase electrode 31b is located at the intermediate position of.

When the mover 21 is stopped, the mover 21
A voltage is applied to the a-phase electrode 27a and the U-phase electrode 31a of the stator 22, and the mover 21 is attracted to the stator 22 and fixedly held by the attraction force due to static electricity generated between these electrodes 27a and 31a. are doing. This electrode 27a, 31a
The voltage is applied to the insulating layers 26 and 30 of the mover 21 and the stator 22 so as not to be charged.

Specifically, during the suspension period of the mover 21, as in the first embodiment, the first adsorption step S
1 ', a first ground connection step S2', a second adsorption step S3 ', and a second ground connection step S4'.
The voltage C is applied to the electrodes 27a, 27b, 31a, 31b of the moving element 21 and the stator 22 by repeating the period C'of a minute time. The first and second adsorption steps S1 'and S3' have the same duration, and the first and second ground connection steps S2 'and S4' have the same duration.

[0081] above the first adsorption step S1 '(time t ₂ from time t ₁ in FIG. 11), as shown in FIG. 12 (A), with respect to a-phase electrodes 27a of the movable element 21 "- “2” is applied to the stator 2 facing the a-phase electrode 27a.
A voltage of "+" polarity is applied to the second U-phase electrode 31a. On the other hand, the b-phase electrode 27b of the mover 21 and the V-phase electrode 31b of the stator 22 are connected to the ground 35 and set to the potential "0". Therefore, this first adsorption step S
In 1 ′, as shown by the arrow in FIG.
The electrostatic attraction force is generated between the No. 1 a-phase electrode 27a and the U-phase electrode 31a, and the stator 22 is attracted to the moving element 21 and is fixedly held in a stopped state.

A first step following the first adsorption step S1 '
In the ground connection step S2 ′ (from time t ₂ to time t _{3 in} FIG. 11), as shown in FIG.
1 and the electrodes 27a, 27b, 31a, 31 of the stator 22
All b are connected to the ground 35, and the potential is set to "0".

[0083] The 'second adsorption step S3 subsequent to the' first ground connection step S2 (time t ₄ from time t ₃ in FIG. 11), the first moving member in the opposite polarity to the adsorption step S1 ' A voltage is applied to the a-phase electrode 27a of 21 and the U-phase electrode 31a of the stator 22. That is, FIG.
As shown in (C), a "+" voltage is applied to the a-phase electrode 27a, and a "-" voltage is applied to the U-phase electrode 31a opposite thereto. Further, the b-phase electrode 27b and the V-phase electrode 31b are connected to the ground 35, and the potential is set to "0".

In the second adsorption step S3 ', as in the case of the first adsorption step S1', as shown in FIG. 12 (C), static electricity is generated between the a-phase electrode 27a and the U-phase electrode 31a. Is generated, and the mover 21 is fixedly held in a stopped state.

Following the second adsorption step S3 ', the second
Ground connection step S4 ′ (from time t ₄ to time t _{5 in} FIG. 11), and as shown in FIG. 12D, the electrodes 27a, 27b, 31a, 3 of the mover 21 and the stator 22 are connected.
All of 1b are connected to the ground 35 to have the potential "0".

As described above, in the third embodiment, it occurs between the a-phase electrode 27a of the moving element 21 and the U-phase electrode 31a of the stator 22 in the first and second adsorption steps S1 'and S3'. The moving force 21 in the stopped state is moved to the stator 22 by the suction force.
Since it is fixedly held, the external holding mechanism need not be provided.

As described above, the polarities of the voltages applied to the a-phase electrode 27a and the U-phase electrode 31a are reversed in the first adsorption step S1 'and the second adsorption step S3', respectively. , And since the durations of the first adsorption step S1 ′ and the second adsorption step S3 ′ are equal, 1
The sum of the voltages applied to the mover 21 and the stator 22 in the cycle C ′ of times is “0”. Therefore, in the first embodiment,
By applying a voltage to the electrodes 27a, 27b, 31a, 31b, it is possible to prevent the insulating layers 26, 30 from being charged.

Furthermore, in the third embodiment, the a-phase and b-phase electrodes 27a and 27b of the mover 21 and the U of the stator 22 are used.
Adsorption step S of applying a voltage having a polarity of "+" or "-" to the electrodes 31a and 31b of the V and V phases
A first ground connection step S1 ′ or a second ground connection step S2 is provided between 1 ′ and the second adsorption step S3 ′, and the a-phase and b-phase electrodes 27a and 27b are provided.
And the electrodes 27a, 27b, 31a, 3 before switching the polarities of the voltages applied to the U-phase and V-phase electrodes 31a, 31b.
The potential of 1b is "0". Therefore, since the polarities of the voltages applied to these electrodes 27a, 27b, 31a, 31b cannot be switched instantaneously and rapidly, so-called ripple noise that causes malfunction can be prevented.

Furthermore, all the electrodes 27a, 27
By providing the first and second ground connection steps S2 ′ and S4 ′ for setting the potentials b, 31a and 31b to “0”, the first and second adsorption steps S1 ′, S1 ′,
By reversing the polarity of the voltage applied at S3 ′, the efficiency of removing charges from the a-phase and b-phase electrodes 27a and 27b and the U-phase and V-phase electrodes 31a and 31b is improved.

[0090] In FIG. 11, during from time t ₆ to time t _23, the operation switch 24 is set to "move to the right".
When the moving element 21 is driven, the voltage is applied by repeating the cycle C including the first to eighth steps S1 to S8,
Moreover, the first to eighth steps S1 to S8 are divided into the first half period p and the second half period q at equal time intervals. In the first half period p of each of steps S1 to S8, a voltage is applied so that the driving force acts on the mover 21, and in the second half period q, the insulating layer 2 is applied.
In order to prevent the charging of 6 and 30, the voltage is applied with the polarity reversed from that in the first half period p.

The first a-phase electrode 27a of the mover 21 has a first
The voltage of "-" polarity is applied in the first half period p of step S1, and the polarity is inverted and the voltage of "+" polarity is applied in the second half period q of the first step S1. The second to eighth steps S2 to S8 are also similar to the first step S1 described above.
A voltage of "-" is applied to the first half period p and a voltage of "+" is applied to the second half period q. A voltage of “+” polarity is applied to the b-phase electrode 27b of the mover 21 in the first half p of the first step S1.
In the latter half q of step S1 of step 1, the polarity is reversed and "-"
The voltage of the polarity is applied. Second to eighth step S2
Similarly, in S8, "-" is assigned to p in the first half and "+" is assigned to q in the second half.
Voltage is applied.

In the third embodiment, since the voltage is applied with such a waveform, both the a-phase and the b-phase electrodes 27a and 27b of the mover 21 are applied in the respective steps S1 to S8. The sum of the voltages becomes "0", and one cycle C
The sum of the voltages applied inside is also "0". Therefore, when the mover 21 is driven, the electrodes 27a, 27b of the mover 21 are driven.
The insulating layer 26 can be prevented from being charged by the voltage applied to the insulating layer 26.

During the moving period of the moving element 21, voltage is applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22 with the same waveform, and the V-phase electrode 31a receives the U-phase. The voltage is applied to the electrode 31b by advancing the phase by 6 steps (3/4 C).

For the U-phase electrode 31a, the first to
From the 8th step S1 to S8 in the first half period p, “+”, respectively, to apply the driving force to the moving element 21,
"+", "0", "-", "-", "-", "0",
Apply "+" voltage. On the other hand, in the second half q of the first to eighth steps S1 to S8, the polarities are inverted to "-""-""0""+""+""+""0", respectively.
A voltage of "-" is applied.

Next, in the V-phase electrode 31b, "0", "+", respectively, in order to apply a driving force to the mover 21 in the first half period p of the first to eighth steps S1 to S8.
Voltages of "+", "+", "0", "-", "-", and "-" are applied. On the other hand, the first to eighth steps S1 to S
In the latter half q of 8, the polarity is reversed with these and “0”
"-", "-", "-", "0", "+", "+",
Apply "+" voltage.

As described above, in the first embodiment, the stator 22
The U-phase and V-phase electrodes 31a and 31b of the
In order to apply the voltage of the opposite polarity to the voltage applied in the first half period p of steps S1 to S8 in the latter half period q, each step S1
The sum of the voltages applied to the U-phase and V-phase electrodes 31a and 31b for each S8 is “0”, and the total of the voltages applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22 for each period C is “0”. The sum of applied voltages is also "0". Therefore, in the electrostatic actuator of the first embodiment, it is possible to prevent the insulating layer 30 from being charged by applying a voltage to the electrodes 31a and 31b of the stator 22 when the moving element 21 is driven.

Next, referring to FIGS. 13 to 17, the movement of the moving element 21 in one cycle C will be described. In addition,
As described above, when the mover 21 is stopped,
The a-phase electrode 27a of the mover 21 and the U-phase electrode 31a of the stator 22 face each other, and the a-phase electrodes 27a and b of the mover 21 are opposed to each other.
Since the V-phase electrode 31b is located at the intermediate position of the phase electrode 27b, it is assumed that the mover 21 and the stator 22 are in the positional relationship when the operation switch 24 is set to "move".

As shown in FIG. 13A, in the first half p of the first step S1 (time t ₆ to time t _{7 in} FIG. 11), the a-phase and b-phase electrodes 27a of the mover 21 are applied. Voltages of "-" and "+" are applied respectively. In addition, the stator 22
The voltage of "+" is applied to the U-phase electrode 31a, and the potential of the V-phase electrode 31b becomes "0".

As shown in FIG. 13B, during the second half q of the first step S1 (time t ₇ to time t _{8 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b, respectively. Further, a voltage of "-" is applied to the U-phase electrode 31a of the stator 22,
The V-phase electrode 31b has a potential "0".

As shown in FIG. 13C, at the start time of the first half p of the second step S2 (time t _{8 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are taken. The voltage applied to is switched to "-" and "+", respectively.
Further, the voltages applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22 are both switched to "+".

As shown in FIG. 13D, during the first half period p of the second step S2 (time t ₈ to time t _{9 in} FIG. 11), the moving element 21 moves relative to the stator 22 in the figure. Moving to the right, the a-phase electrode 27a is located at an intermediate position between the U-phase electrode 31a and the V-phase electrode 31b.

As shown in FIG. 13E, during the second half q of the second step S2 (from time t ₉ to time t _{10 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b, respectively. Further, a voltage of "-" is applied to both the U-phase and V-phase electrodes 31a and 31b of the stator 22.

As shown in FIG. 14A, at the start point of the first half p of the third step S3 (time t _{10 in} FIG. 11), the voltage is applied to the a-phase and b-phase electrodes 27a and 27b of the mover 21. The polarity of the applied voltage is switched to "-" and "+", respectively. In addition, the U-phase and V-phase electrodes 31a, 31 of the stator 22
The voltage applied to b switches to "0" and "+", respectively.

As shown in FIG. 14B, during the first half p of the third step S3 (time t ₁₀ to time t _{11 in} FIG. ₁₁ ), the mover 21 moves to the right side in the drawing and moves. Child 21 a
The phase electrode 27 a faces the V-phase electrode 31 b of the stator 22.

As shown in FIG. 14C, in the second half q of the third step S3 (from time t ₁₁ to time t _{12 in} FIG. 11), the a-phase electrodes 27a and 27b of the mover 21 are not connected. Voltages of "+" and "-" are applied respectively. In addition, the stator 22
“0” is applied to the U-phase electrodes 31a and 31b of
A voltage of "-" is applied.

As shown in FIG. 14D, at the start point of the first half p of the fourth step S4 (time t _{12 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are obtained. The polarity of the voltage applied to the switch switches between "-" and "+", respectively. In addition, the U-phase and V-phase electrodes 31a of the stator 22,
The polarity of the voltage applied to 31b switches to "-" and "+".

As shown in FIG. 14E, the first half p of the fourth step S4 (time t ₁₂ to time t _{13 in} FIG. 11)
Then, the mover 21 moves to the right side in the drawing, and the a-phase electrode 27a of the mover 21 and the V-phase electrode 31b of the stator 22 are overlapped by half in the width direction.

As shown in FIG. 15A, the fourth step
Second half of q in S4 (time t in FIG. 11) ₁₃From time t₁₄)
Is applied to the a-phase and b-phase electrodes 27a and 27b of the mover 21.
Voltages of "+" and "-" are applied respectively. Also solid
For the U-phase and V-phase electrodes 31a and 31b of the determinator 22, respectively.
Then, "+" and "-" voltages are applied.

As shown in FIG. 15B, at the start point of the first half p of the fifth step S5 (time t _{14 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are obtained. The polarity of the voltage applied to is switched to "-" and "+", respectively. Further, the U-phase and V-phase electrodes 31a, 3 of the stator 22
The polarity of the voltage applied to 1b switches between "-" and "0".

As shown in FIG. 15C, in the first half p of the fifth step S5 (from time t ₁₄ to time t _{15 in} FIG. 11), the mover 21 moves to the right in the figure and moves. Child 21 b
The phase electrode 27b and the U-phase electrode 31a of the stator 22 are in a state of facing each other.

As shown in FIG. 15D, in the second half q of the fifth step S5 (time t ₁₅ to time t _{16 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b, respectively. Further, voltages of "+" and "0" are applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22.

As shown in FIG. 15E, at the start point of the first half p of the sixth step S6 (time t _{16 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are taken. The polarity of the voltage applied to is switched to "-" and "+", respectively. In addition, the U-phase and V-phase electrodes 31a of the stator 22,
Both of the voltages applied to 31b switch to "-".

As shown in FIG. 16 (A), during the first half p of the sixth step S6 (time t ₁₆ to time t _{17 in} FIG. 11), the mover 21 moves to the right side in the figure and moves. 21 a
-Phase and b-phase electrodes 27a and 27b are the U-phase and V-phase of the stator 22.
It is in a state of being located at an intermediate position between the phase electrodes 31a and 31b.

As shown in FIG. 16B, in the second half q of the sixth step S6 (time t ₁₇ to time t _{18 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b. In addition, the stator 22
A voltage of "+" is applied to both the U-phase and V-phase electrodes 31a and 31b.

As shown in FIG. 16C, at the starting point of the first half p of the seventh step S7 (time t _{18 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are obtained. The voltage applied to is switched between "-" and "+". Also,
The voltages applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22 are switched between "0" and "-".

As shown in FIG. 16D, in the first half p of the seventh step S7 (from time t ₁₈ to time t _{19 in} FIG. 11), the mover 21 moves to the right side in the figure, and the mover 21 moves. The b-phase electrode 27b of 21 and the V-phase electrode 31b of the stator 22 face each other.

As shown in FIG. 16E, in the second half q of the seventh step S7 (time t ₁₉ to time t _{20 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b, respectively. The voltages applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22 are "0" and "+", respectively.

As shown in FIG. 17A, at the start of the first half p of the eighth step S8 (time t _{20 in} FIG. 11), the a-phase and b-phase electrodes 27a and 27b of the mover 21 are taken. The voltage applied to the switch is switched to "-" and "+", respectively.
Further, the voltages applied to the U-phase and V-phase electrodes 31a of the stator 22 are switched to "+" and "-", respectively.

As shown in FIG. 17B, in the first half p of the eighth step S8 (time t ₂₀ to time t _{21 in} FIG. 11), the mover 21 moves to the right side in the figure, and the mover 21 moves. 21 a
Electrodes 27a and 27b for the phase b and the phase b, respectively,
Half of the U-phase and V-phase electrodes 31a and 31b in the width direction overlap each other.

As shown in FIG. 17C, in the second half q of the eighth step S8 (time t ₂₁ to time t _{22 in} FIG. 11), the a-phase and b-phase electrodes 27a, Voltages of "+" and "-" are applied to 27b, respectively. Further, "-" and "+" voltages are applied to the U-phase and V-phase electrodes 31a and 31b of the stator 22, respectively.

As described above, in the electrostatic actuator according to the third embodiment, steps S1 to S8 are performed during the driving period.
Is divided into a first half period p and a second half period q, and a voltage is applied to the electrodes 27a, 27b, 31a, 31b of the mover 21 and the stator 22 so that the driving force acts on the mover 21 in the first half period p. Meanwhile, in the second half q of each step S1 to S9, a voltage is applied with the polarity reversed from that of the first half p, and the voltage applied to each of the electrodes 27a to 31b in each step S1 to S8. Since the sum is "0", the insulating layers 26 and 30 of the moving element 21 and the stator 22 can be prevented from being charged. In addition, in the present embodiment, the electrode 2 of the mover 21 is
Since the sum of the voltages applied to 7 a to 27 c and the stator 22 during one cycle C is also “0”, this also charges the insulating layers 26 and 30 of the mover 21 and the stator 22. Can be prevented.

As described above, in the third embodiment, the moving element 2
The electrodes 27a of the mover 21 and the stator 22 while driving
Since the insulating layers 26 and 30 of the moving element 21 and the stator 22 can be prevented from being charged by applying a voltage to the moving element 31b, the insulating layer 26 and 30 are charged and the moving element 21 and
Electrodes 27a, 27b and electrodes 31a, 31 of the stator 22
It is possible to prevent the driving force of the moving element 21 from decreasing due to the reduction of the electrostatic force acting during b.

The operation switch 14 is "moved to the left".
Is set to, the electrodes 31a, 31a of the stator 22 are
U having the same pattern with respect to b and the V-phase electrode 31b
It suffices to delay the phase by 6 steps from the phase electrodes 31a, switch the polarities, and apply the voltage.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, when the electrostatic actuator of the first embodiment is arranged in the vertical direction so that the electrodes of the mover 21 are arranged in the order of U phase, V phase, and W phase from above, the mover 21 During the stop, the polarity may be cyclically switched to the voltage applied to the electrodes 27a to 27c of the mover 21 as described below. That is, in the first step, voltages of "+", "-", and "-" are applied to the U-phase electrode 27a, the V-phase electrode 27b, and the W-phase electrode 27c, respectively. Voltages of "-", "-", and "+" are applied, and in the next step, they are applied to "-", "+", and "-". When a voltage is applied to the electrodes 31a to 31c of the stator 22 in this way, the voltage is switched in the direction opposite to the gravity acting on the mover 21, so that the electrodes 31a to 31c are switched.
A weak force in the upward direction is generated due to the shift in the switching time of the voltage generated in the. Since this weak force suppresses the fall, the holding force becomes stronger.

[0125]

According to the present invention, each step of each cycle is divided into the first half period and the second half period when the moving element is driven, and the moving element is applied so that the driving force acts on the moving element in the first half term. In addition, when the voltage is applied to the electrodes of the stator and the electrodes in the latter half of the period while the voltage is applied by reversing the polarity in the first half of the period, the insulating layers of the movable unit and the stator are charged while the movable unit is being driven. Can be prevented.

When the moving element is stopped, voltages of different polarities are applied to the electrodes of the moving element and the electrodes of the stationary element which face each other, and the electrodes of the moving element and the stator are applied to each other. In the case where the voltage is applied by alternately switching positive and negative, the moving element is held by the attraction force generated between the electrode of the moving element and the electrode of the stator. Further, since the voltages applied to the electrodes of the mover and the stator are not biased, it is possible to prevent the insulating layers of the mover and the stator from being charged.

At the time of stopping the mover, before switching the polarity of the voltage applied to each electrode of the mover and the stator,
When the step of connecting the electrode to the ground is provided, it is possible to prevent the occurrence of so-called ripple noise that causes malfunction.

In the electrostatic actuator according to the present invention, the electrodes of the mover are arranged every two electrodes and are connected to each other to form three phases, and the electrodes of the stator are arranged every two lines. The electrodes may be connected to each other to form three phases (Claim 4), or the electrodes of the moving element may be connected to each other to form two phases. At the same time, two electrodes of the stator may be connected to each other to form two phases.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram showing an electrostatic actuator according to a first embodiment of the present invention.

2A is a partial plan view showing a mover, and FIG. 2B is a partial plan view showing a stator.

FIG. 3 is a voltage waveform diagram for explaining the operation of the electrostatic actuator of the first embodiment.

4 (A), (B), (C) and (D) are partial schematic diagrams showing voltages applied while the moving element is stopped.

5 (A), (B), (C), (D), (E)
FIG. 7 is a partial schematic diagram showing application of voltage during movement of a moving element.

6 (A), (B), (C), and (D) are partial schematic diagrams showing application of voltage during movement of a moving element.

FIG. 7 is a voltage waveform diagram showing a second embodiment.

8 (A), (B), (C) and (D) are partial schematic diagrams showing voltages applied while the moving element is stopped.

FIG. 9 is a schematic circuit diagram showing an electrostatic actuator according to a second embodiment of the present invention.

FIG. 10A is a partial plan view showing a moving element, and FIG.
FIG. 4 is a partial plan view showing a stator.

FIG. 11 is a voltage waveform diagram for explaining the operation of the electrostatic actuator of the second embodiment.

12 (A), (B), (C), and (D) are partial schematic diagrams showing application of voltage while the moving element is stopped.

13 (A), (B), (C), (D), (E)
FIG. 7 is a partial schematic diagram showing application of voltage during movement of a moving element.

14 (A), (B), (C), (D), (E)
FIG. 7 is a partial schematic diagram showing application of voltage during movement of a moving element.

15 (A), (B), (C), (D), (E)
FIG. 7 is a partial schematic diagram showing application of voltage during movement of a moving element.

16 (A), (B), (C), (D), (E)
FIG. 7 is a partial schematic diagram showing application of voltage during movement of a moving element.

17 (A), (B), and (C) are partial schematic diagrams showing application of voltage during movement of a moving element.

FIG. 18 is a partial schematic view showing an example of a conventional electrostatic actuator.

19 is a diagram showing a waveform of a voltage applied to the electrostatic actuator of FIG.

[Explanation of symbols]

 21 mover 22 stator 23 control means 24 operation switch 25 high voltage source 26, 30 insulating layer 35 ground 27a to 31c electrodes R1 to R46 relay

Claims (5)

[Claims] 1. A stator having a plurality of electrodes arranged on an insulating layer, and a mover having a plurality of electrodes arranged on the insulating layer so as to be movable with respect to the stator. An electrostatic actuator that drives a mover by applying a voltage to the mover's electrode to generate a repulsive force between the mover's electrode and the stator's electrode. Voltage is applied to the electrodes of the stator and the stator by switching the polarity in a cycle consisting of a plurality of steps, and each step of each cycle is divided into a first half period and a second half period,
In the first half of each step, a voltage is applied to the electrodes of the mover and the stator so that the driving force acts on the mover, while in the second half of each step, the voltage and polarity applied in the first half are changed. An electrostatic actuator characterized in that an inverted voltage is applied. 2. A stator having a plurality of electrodes arranged on an insulating layer, and a mover having a plurality of electrodes arranged on the insulating layer so as to be movable with respect to the stator. An electrostatic actuator that drives a mover by applying a voltage to the electrode of the mover and the repulsive force generated between the electrode of the mover and the electrode of the stator. , The electrodes of the moving element and the electrode of the stator facing each other are applied with voltages of different polarities, and the electrodes of the moving element and the stator are alternately switched between positive and negative to apply the voltage, so that the moving element and the fixed element are fixed. An electrostatic actuator characterized in that a voltage is applied to a child electrode by switching a polarity in a cycle including a plurality of steps. 3. The electrostatic actuator according to claim 2, further comprising a step of connecting the electrodes to the ground before switching the polarities of the voltages applied to the electrodes of the mover and the stator. . 4. The electrodes of the mover are connected to each other every two electrodes arranged to form three phases, and the electrodes of the stator are connected to each other arranged every two electrodes. The electrostatic actuator according to any one of claims 1 to 3, wherein the electrostatic actuator has three phases. 5. The electrodes of the mover are connected to each other by arranging every other electrode to form two phases, and the electrodes of the stator are connected to each other by arranging every other electrode. The electrostatic actuator according to any one of claims 1 to 3, wherein the electrostatic actuator has two phases.