JP3144500B2 - Electrostatic actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-small electrostatic actuator having an outer shape of less than millimeters for displacing an object by using electrostatic force between electrodes.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional example of this kind. this is,
The comb-shaped fixed electrode K and the movable electrode M are engaged with each other with an appropriate gap provided, and a voltage is applied to both to displace the comb-teeth in the longitudinal direction of the comb-teeth, so that electrostatic driving proportional to the number of comb-teeth is performed. To gain strength. When a voltage is applied as shown in the figure, the displacement is performed in the direction of arrow R1. In addition, H shows a support part (fixed part). The electrostatic driving force F acting in this case is as follows: ε is relative permittivity, ε ₀ is vacuum permittivity, d is gap distance, n is the number of comb teeth, t is tooth thickness, and V is applied voltage. F = ε · ε ₀ · n · t · V ² / 2d (1)

FIG. 6 shows another conventional example. In this method, a fixed electrode K and a movable electrode M are arranged to face each other, and a voltage is applied to both electrodes to obtain an electrostatic driving force in the direction of decreasing the gap as indicated by arrow F. In this case, the electrostatic driving force F is ε is a relative permittivity, ε ₀ is a vacuum permittivity, d is a gap distance, S
Where F is the facing area and V is the applied voltage, F = ε · ε ₀ · S · V ² / 2d ² (2)

[0004]

However, since all of the above-mentioned devices have extremely small displacements, their application range and applications are limited, and there is a problem that they cannot be applied to applications requiring large displacements. Therefore, an object of the present invention is to enable a particularly large displacement to be generated.

[0005]

To solve Means for Solving the Problems] The above problems, in the invention of this, a plurality of movable electrodes plurality of relative stator having a fixed electrode of a pair of the divided through an insulator elastic Connected via a support member, a voltage is applied from each fixed electrode via an elastic support member so that adjacent electrodes have different polarities, and a movable electrode is applied using an electrostatic force acting between each electrode. Displacement electrostatic actuator
There are, the spring constant of the plurality of elastic support members, the stator
The spring force gradually weakens in the order from near to far away
It is characterized in that it is set differently from each other so that it can be adjusted .

[0006]

According to the present invention, a movable electrode or a movable element is supported by a support spring (elastic support section).
Material) and their spring constant
Springs in order from the one near the stator to the one farther away.
Set differently so that the power gradually weakens,
By applying a voltage through this support spring, it is relatively simple.
A large displacement can be obtained with a simple structure.

[0007]

FIG . 1 is a perspective view for explaining the principle of the present invention.
FIG. In the drawing, reference numeral 1 denotes fixed electrodes 1A and 1B.
The stator 2 is composed of a plurality of movable electrodes 2A to 2N.
4 is an insulator, 4 is a support spring (elastic support member), 5
Denotes a sliding portion, and 6 denotes a glass substrate. sand
That is, the stator 1 and a plurality of movable electrodes 2A to 2N can be used.
The armature 2 is connected to each other via a support spring 4 and is made of glass.
It is arranged on a substrate 6. Stator 1 and first mover 2A
Are movable between the movable elements 2A and 2B, 2B and 2C.
3, each mover 2 is insulated as shown in FIG.
In order to prevent the entire lower surface from touching the glass substrate 6,
Therefore it is supported.

Accordingly, the fixed electrodes 1A, 1 of the stator 1
When a DC voltage E as shown in FIG.
1A and movable electrode 2A, movable electrodes 2A and 2B, 2B and 2C
.., An electrostatic force as shown in the above equation (2) is generated.
You. The electrodes are connected to each other via a support spring 4.
Therefore, it is possible if the electrostatic force between the electrodes overcomes the force of the support spring.
The moving element 2 is attracted to the stator 1 so that the reference position
In the direction of the arrow (displacement amount x). Yes
Is it easy to form a large number of moving elements 2?
Large displacement can be obtained with a simple structure.
You. FIG. 2 shows the relationship between the applied voltage E and the displacement x.
become that way. Applied voltage E0 is supported by electrostatic force between electrodes
Shows the voltage at which the force of the spring is overcome. Also here
Although the applied voltage is DC, it is repeated with a pulsed voltage.
The driving may be performed repeatedly.

FIG . 3 is a perspective view showing an embodiment of the present invention.
You. This is because the one shown in FIG.
Although they are connected to each other via a supporting spring 4 having a force,
However, in this embodiment, the stator 1 is far away from
The spring force of the support spring 4 is gradually reduced
Ru der those way. Here, the width of the support spring 4 is
The spring force is gradually reduced by narrowing it.
Alternatively, the thickness may be changed. like this
Then, the relationship between the applied voltage E and the displacement x is changed as shown in FIG.
The relationship can be a step-like relationship, and the magnitude of the applied voltage E
Can be obtained. Applied voltage E1
However, when the electrostatic force between the electrodes overcomes the force of the support spring at the tip,
The voltage of

[0010]

According to the present invention, the movable electrode or the movable electrode
Are connected to each other via a support spring and the stator
The order of the support spring
The spring force is gradually reduced, and the voltage is applied through this support spring.
Since the voltage is applied, the steps can be performed with a relatively simple structure.
Has the advantage that it is possible to obtain large displacements
Brought.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining the principle of the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of FIG. 1;

FIG. 3 is a perspective view showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining the operation of FIG. 3;

FIG. 5 is a schematic diagram showing a conventional example .

FIG. 6 is a schematic diagram showing another conventional example .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stator, 1A, 1B ... Fixed electrode, 2 ... Mover, 2A
２2N: movable electrode, 3: insulator, 4: support spring, 5: sliding portion, 6: glass substrate.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02N 1/00

Claims (1)

(57) [Claims] 1. A plurality of movable electrodes are connected via a plurality of elastic support members to a stator having a pair of fixed electrodes divided through an insulator, and adjacent electrodes have different polarities. As described above, in an electrostatic actuator that applies a voltage from each fixed electrode via an elastic supporting member and displaces a movable electrode by using an electrostatic force acting between the electrodes, the spring constant of the plurality of elastic supporting members is , Close to the stator
The spring force is gradually weakened in the order of
An electrostatic actuator characterized by being set differently from each other .