JP2000099153A - Displacement expanding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small displacement expanding mechanism having a large displacement expansion ratio. SOLUTION: The displacement expanding mechanism 1 is provided with a fixed stand 20 integrally attachable to a fixed base 18, a mobile stand 22 elastically supported through parallel springs 30, a first arm 24 extended in the direction of arrow X while supporting one end on the fixed stand, a connecting spring 26 for connecting the other end of this first arm and the mobile stand, a second arm 28 extended parallelly with the first arm while supporting one end on the fixed stand, a link means for linking the first and second arms, and a laminated piezoelectric body 42 for applying pressure from the direction (the direction of arrow Y) orthogonal to the extending direction of the second arm to the second arm. On the first arm, a through hole 44 or through groove 46 capable of inserting the piezoelectric body is formed and by arranging the piezoelectric body through this through hole or through groove, the pressure of the piezoelectric body can be applied only to the second arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in, for example, a scanning probe microscope and a scanning laser microscope, and is a displacement enlarging mechanism for accurately displacing a moving object (for example, a stage) in a predetermined direction by a predetermined amount. About.

[0002]

2. Description of the Related Art Conventionally, for example, in an electron microscope or an ultra-precision processing machine, a stage for setting a measurement object or a processing object, and an elasticity for moving the stage in a predetermined direction by a predetermined amount with high precision. A spring guide is provided. Since the elastic spring guide does not have a sliding part with respect to other parts,
It is not affected by friction or wear.

In order to move the stage, a piezoelectric material is generally used frequently. However, since the displacement of the piezoelectric material is very small, for example, as disclosed in Japanese Patent Laid-Open No. 1-219602, The stage is moved by enlarging the displacement of the piezoelectric body using the lever enlarging mechanism.

FIG. 6 shows a conventional displacement enlarging mechanism having a lever enlarging mechanism. The displacement enlarging mechanism includes a fixed base 4 attached to a fixed base 2 and a hinge spring 6 attached to the fixed base 4. And a stage 12 connected to the arm 8 via a connection spring 10, and a piezoelectric body arranged to be able to press the side surface of the arm 8 in the arrow Y direction. 14 and a pair of parallel springs 16 that support the stage 12 so as to be displaceable in the arrow Y direction.

Here, assuming that the distance from the hinge spring 6 serving as the fulcrum B of the lever expanding mechanism to the output end A of the arm 8 is L, and the distance from the fulcrum B to the pressing point C of the piezoelectric body 14 is b.
As the distance L is increased with respect to the distance b (the leverage L
As the value of / b is increased, the displacement enlargement ratio of the output end A is increased, and as a result, the displacement of the stage 12 (the amount of movement in the arrow Y direction) can be increased.

[0006]

However, in the conventional displacement enlarging mechanism, during operation of the lever enlarging mechanism, the hinge spring 6 is elastically deformed to cause the position of the fulcrum B to be displaced, or the pressing force of the piezoelectric body 14 causes the arm to be displaced. When the arm 8 is elastically deformed in a curved shape, the displacement enlargement ratio of the output end A of the arm 8 does not always coincide with the leverage and becomes a low value.

In order to increase the displacement enlargement ratio, it is conceivable to increase the lever ratio by increasing the length of the arm 8 in the direction of the arrow X. However, the displacement enlargement mechanism is correspondingly increased in size in the direction of the arrow X. It will be.

On the other hand, a method of increasing the displacement of the output end A of the arm 8 by using a large piezoelectric body 14 is also conceivable. However, in this method, although the length of the arm 8 in the direction of the arrow X is reduced, the length of the piezoelectric body 14 in the direction of the arrow Y is increased, and the displacement enlarging mechanism is correspondingly moved by the arrow Y.
It becomes larger in the direction.

For example, it is necessary to provide a small displacement magnifying mechanism on a small stage used under a microscope. However, if the displacement magnifying mechanism becomes large as described above, the entire stage or the entire microscope becomes large. It leads to the conversion. The present invention has been made to solve such a problem, and an object of the present invention is to provide a small displacement magnifying mechanism having a large displacement magnifying power.

[0010]

In order to achieve the above object, a displacement enlarging mechanism according to the present invention comprises a fixed base which can be integrally attached to a fixed base, and an elastic support member. , A first arm having one end supported by the fixed base, a connection spring connecting the other end of the first arm and the movable base, and one end supported by the fixed base. A second arm extending in parallel with the first arm, connecting means for connecting the first arm and the second arm, and a second arm extending in a direction in which the second arm extends. A pressing element for applying a pressing force to the second arm from a direction perpendicular to the second arm.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A displacement magnifying mechanism according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a configuration of a displacement magnifying mechanism 1 according to the present embodiment.
, A movable base 22 elastically supported via an elastic support member, and a fixed base 2
0, one end of which is supported at one end and extends in the direction of the arrow X;
Connecting the first arm 24 and the second arm 28, a second arm 28 having one end supported by the fixed base 20 and extending in parallel with the first arm 24. And a pressing element for applying a pressing force to the second arm 28 in a direction (arrow Y direction) orthogonal to the extending direction of the second arm 28.

The fixed base 20 is configured to be attached to the fixed base 18 later, or to be integrally attached to the fixed base 18 in advance. The moving table 22 can be used, for example, as a stage arranged under a microscope.

In the present embodiment, as the elastic support member,
As an example, a pair of parallel springs 30 that support the movable table 22 so as to be movable in the arrow Y direction is applied. The connection spring 26 has two sides 26a extending in parallel along the moving direction of the movable base 22 (arrow Y direction) and two sides 26b extending in parallel in a direction perpendicular to the direction (arrow X direction). And the two sides 26a and 26b facing each other have the same length, and the two sides 26a parallel to the moving direction of the moving table 22 are It is longer than the other two sides 26b. According to the configuration of the connection spring 26, the rigidity is high in the moving direction of the moving table 22, and
Rigidity decreases in a direction perpendicular to the movement direction (arrow X direction).

The first arm 24 has one end connected to the fixed base 20 via a first hinge spring 32 and the other end connected to the movable base 22 via the connection spring 26 described above. . The second arm 28 has one end connected to the fixed base 20 via a second hinge spring 34, and the other end connected to the other end of the first arm 24 via a connecting means described later. Are linked. In this case, the first arm 24 is configured to be rotatable about the first hinge spring 32 as a fulcrum, and the second arm 28 is configured to be rotatable about the second hinge spring 34 as a fulcrum. The other end of the first arm 24 means a position shifted from the other end of the first arm 24 toward the one end by a predetermined amount.

The connecting means includes a rigid connecting member 40 connected to the other end of the first arm 24 and the other end of the second arm 28 via hinge springs 36, 38. In the present embodiment, as an example, a laminated piezoelectric body 42 that can expand and contract along the arrow Y direction is applied as the pressing element. The piezoelectric body 42 extends from the first arm 24 side toward the second arm 28 in the arrow Y direction, and is configured to apply a pressing force only to the second arm 28. . Specifically, the first arm 24 has a through hole 44 (see FIG. 1B) or a through groove 46 (see FIG. 1C) through which the piezoelectric body 42 can be inserted. Piezoelectric body 42 through through hole 44 or through groove 46
Is arranged, the pressing force of the piezoelectric body 42 can be applied only to the second arm 28.

When the moving table 22 is moved in the direction of arrow Y, the piezoelectric body 42 is extended and a part (C) of the second arm 28 is extended.
When a pressing force is applied to (point), the second arm 28
Is rotationally displaced with the hinge spring 34 as a fulcrum (point B).
At this time, the portion (point A) of the hinge spring 36 connecting the other end of the second arm 28 and the connecting member 40 is
Displacement exceeds the displacement (elongation) of. At the same time,
Since the connecting member 40 is pulled and displaced by the hinge spring 36, a portion (point G) of the hinge spring 38 connecting the connecting member 40 and the other end of the first arm 24 is also pulled and displaced by the connecting member 40. I do. At this time, the first arm 24
Is rotationally displaced about the first hinge spring 32 as a fulcrum (point E) in accordance with the amount of displacement at point G. As a result, the movable table 22 connected to the other end of the first arm 24 via the connection spring 26 can be moved in the arrow Y direction. In this case, the displacement at the joint point D between the first arm 24 and the connection spring 26 becomes the output displacement of the displacement enlarging mechanism.

Here, considering the configuration of the conventional displacement enlarging mechanism shown in FIG. 6, an unused space is widened on the upper side of the arm 8. In the displacement enlarging mechanism 1 of the present embodiment described above, the piezoelectric body 42 is extended and disposed over the unused space in the related art without changing the size of the piezoelectric body 42 which is relatively longer than the conventional one without changing the dimensions of the entire displacement enlarging mechanism. As a result, the output displacement of the piezoelectric body 42 can be increased, so that even if the leverage ratio is small at the joint point D between the first arm 24 and the connection spring 26, a large enough to compensate for it. It is possible to obtain a displacement magnification. In other words, in the displacement enlarging mechanism 1 of the present embodiment, one end (point C) of the piezoelectric body 42 presses the second arm 28 and the other end of the piezoelectric body 42 2 arm 2
8 is fixed to a fixed base 18 on the opposite side. For this reason, it is possible to configure the piezoelectric body 42 that is relatively longer than before, and as a result, it is possible to move the movable base 22 at a larger displacement magnification than before.

Further, according to the above-described embodiment, since the first and second arms 24 and 28 can be shortened, the size of the displacement enlarging mechanism can be reduced.
As a result, the leverage ratio can be reduced, and the displacement expansion efficiency can be increased.

Next, the relationship between the output displacement of the displacement magnifying mechanism 1 and the lengths of the first and second arms 24 and 28 that determine the size of the displacement magnifying mechanism 1 will be described with reference to FIG. . FIG. 2 shows an analysis model corresponding to the configuration of the displacement magnifying mechanism 1 of FIG. In this case, in order to simplify the analysis, each hinge spring 32, 34, 36,
The torque generated at 38 is ignored. Also, reference numerals A, B, C, D, E, and G shown in FIG.
Respectively correspond to the position of each member shown in FIG.

In this case, the length between the AB of the second arm 28 is L _1, and the length between the DE of the first arm 24 is L ₂
And the pressing point C of the piezoelectric body 42 against the second arm 28
Is defined as a distance a from A and a distance b from B.
When the pressing force F is applied to the pressing point C, the first and second arms 24 and 28 are displaced as shown in FIG.

At this time, the load acting on each member position is:
It is represented by the following equation. _{R A = (b / L 1} ) · F R B = (b / L 1) · F R D = (b / L 1) · (e / L 2) · F R E = (b / L 1) · (D / L ₂ ) · F Next, the stiffness in the Y direction at each member position is represented by k _A , k _B , k
_Assuming that _C , k _D , k _E , and k _G (see FIG. 2A), the displacement at each member position is, as shown in FIG. 2B, y _A = (R _A / k _A ) + y _G ... (displacement of the hinge spring _{36) y B = (R B} / k B) ... ( displacement of point C of the second arm 28) (second displacement of the hinge spring _{34) y C = y C1 +} y C2 ... y _{D = R D / k D ...} ( output displacement of the first arm 24) (displacement of the first hinge spring _{32) y E = R E /} k E ... y G = y G1 + y G2 ... ( first arm 24 and the displacement of the connecting portion between the hinge spring 38).

_{Further, y C1 = y B + {} (y A -y B) / L 1} · b y C2 = F / k C y G1 = y E + {(y D -y E) / L 2} Since ey _G2 = R _A / k _G , if these are arranged for y _C , the following equation is obtained.

[0023]

(Equation 1)

The pressing point C of the piezoelectric body 42 against the second arm 28 coincides with the displacement of the piezoelectric body 42. In this case, assuming that the displacement of the piezoelectric body 42 in a state where the pressing force is not applied to the second arm 28 is y _PZT , the displacement of the piezoelectric body 42 when the pressing force F is applied to the pressing point C is:

[0025]

(Equation 2) It is expressed as From the above equations (1) and (2), the pressing force F
Is required.

[0026]

(Equation 3) At this time, the output displacement y _D of the displacement enlarging mechanism 1 (the output displacement of the first arm 24) is obtained from the following equation.

[0027]

(Equation 4)

FIG. 3 shows an arm 8 of a conventional displacement enlarging mechanism.
(See FIG. 6) The characteristic S1 of the output displacement with respect to the length, and the first and second arms 2 of the displacement magnifying mechanism 1 of the present embodiment.
The relationship between the output displacement characteristics S2 and the lengths of 4, 28 is shown.

As is clear from the comparison of these characteristics S1 and S2, according to the displacement enlarging mechanism 1 of the present embodiment, it is possible to obtain the same output displacement as the conventional one even with a very short arm length. Becomes

As described above, according to the present embodiment, a small displacement enlarging mechanism having a large displacement enlarging ratio can be provided. Note that the present invention is not limited to the above-described embodiment, and can be variously modified as follows.

As a first modified example, as shown in FIG. 4, for example, the distance e from the first hinge spring 32 to the hinge spring 38 and the distance e from the first hinge spring 32 to the first arm 24 are changed.
The ratio ε = L ₂ / e of the distance L _{2 to} the output displacement end (joint point D between the first arm 24 and the connection spring 26) is larger than that in the above-described embodiment (particularly, see FIG. 2). You may. In this case, the piezoelectric body 42 has a through hole (see FIG. 1B) or a through groove (see FIG. 1C) formed in the fixed base 20.
The second arm 28 is configured to apply a pressing force through the second arm 28.

The other configuration is the same as that of the above-described embodiment, and therefore, the same reference numerals are given and the description is omitted. According to the displacement enlarging mechanism 1 of this modified example, by increasing ε, it is possible to obtain a larger output displacement than in the above-described embodiment.

As a second modified example, the moving table 22 is moved so that the moving table 22 can move in the orthogonal XY directions.
A pair of displacement magnifying mechanisms may be arranged at symmetrical positions with respect to each of the moving axes. For example, as shown in FIG. 5, four displacement magnifying mechanisms 1 'and 1 "may be respectively arranged at symmetrical positions with respect to the center line of the moving table 22.

The configuration of the displacement enlarging mechanism 1 ', 1 "of this modification is basically the same as that of the above-described embodiment,
The movable table 22 is moved by the connecting springs 26 ′ of a pair of symmetrically arranged displacement magnifying mechanisms 1 ′ and the connecting springs 26 ′ of a pair of symmetrically arranged displacement magnifying mechanisms 1 ″.
It is elastically supported so as to be movable in the Y direction.

In this modification, the connection spring 26 '
It is composed of two sides 26a 'extending parallel to the moving direction of the moving table 22 (arrow X direction) and two sides 26b' extending parallel to the direction perpendicular to the direction (arrow Y direction). Two sides 26 each facing each other.
a 'and 26b' have the same length as each other, and two sides 26a 'parallel to the moving direction of the moving table 22 are longer than the other two sides 26b'. This connection spring 26 '
According to the configuration, the moving direction of the movable base 22 (the direction of the arrow X)
In the direction perpendicular to the moving direction (arrow Y
Direction), the rigidity decreases.

The connection spring 26 ″ is connected to two sides 26 extending in parallel in the moving direction of the moving table 22 (the direction of arrow Y).
a "and two sides 26b" extending in parallel along a direction (arrow X direction) perpendicular thereto, and form a hollow rectangular shape.
b ″ have the same length as each other, and two sides 26a ″ parallel to the moving direction of the moving table 22 are longer than the other two sides 26b ″. Configuration of this connection spring 26 ″ According to the above, rigidity is high in the moving direction of the moving table 22 (arrow Y direction) and low in the direction perpendicular to the moving direction (arrow X direction).

In this modification, the connection springs 26 ', 26 "for elastically supporting the movable table 22 are connected to the connecting member 4
0, each displacement magnifying mechanism 1 ′,
The displacement output position of 1 ″ becomes these connecting members 40. Therefore, each connecting member 40 applied to the present modified example is symmetrical with respect to the center line of the movable base 22.

The other configuration is the same as that of the above-described embodiment, and therefore, the same reference numerals are given and the description is omitted. In such a configuration, the movable base 22 is indicated by an arrow Y
When the piezoelectric elements 42 of the pair of displacement magnifying mechanisms 1 ″ are extended to apply a pressing force to the second arm 28, as a result, the pair of displacement magnifying mechanisms 1 ″ exceeds the amount of displacement (elongation) of the pair of displacement bodies 1 ″. The connecting member 40 is simultaneously displaced in the Y direction, and at this time, the connecting spring 26 ″ connected to the pair of connecting members 40.
Move in the arrow Y direction by an amount corresponding to the amount of displacement of the pair of connecting members 40 with little elastic deformation because the rigidity is increased in the moving direction of the movable table 22 (arrow Y direction). . As a result, the movable base 22 can be moved in the arrow Y direction at a large displacement magnification.

On the other hand, when the movable table 22 is moved in the direction of the arrow X, the piezoelectric body 42 of the pair of displacement magnifying mechanisms 1 'is extended to apply a pressing force to the second arm 28. As a result,
The pair of connecting members 40 are simultaneously displaced in the X direction beyond the displacement (elongation) of the piezoelectric body 42. At this time, the connection springs 26 ′ connected to the pair of connecting members 40 have high rigidity in the moving direction of the moving table 22 (in the direction of the arrow X), so that the connection springs 26 ′ are hardly elastically deformed. Connecting member 4
It moves in the direction of the arrow X by an amount corresponding to the displacement amount of zero. As a result, the movable base 22 can be moved in the direction of the arrow X with a large displacement magnification.

As described above, according to this modification, the movable base 22 is moved at a large displacement magnification by the small displacement magnification mechanism 1 ', 1 "which can use the piezoelectric member 42 which is relatively long compared to the conventional one.
It can be moved in the Y direction.

In the above-described embodiment and the first and second modified examples, each hinge spring 32, 34, 36, 3
Although an arc-shaped member as shown in the figure is used as 8, any shape such as a leaf spring may be used as long as the member has the same effect.

The present invention includes the following inventions. (1) A fixed base that can be integrally attached to a fixed base, a movable base that is elastically supported via an elastic support member, a first arm that has one end supported by the fixed base, A connection spring for connecting the other end of the first arm to the movable table, a second arm supported at one end by the fixed table and extending in parallel with the first arm; and the first arm Connecting means for connecting the second arm and the second arm;
From the direction perpendicular to the direction in which the arm extends.
And a pressing element for applying a pressing force to the arm. (2) The pressing element extends from the first arm side toward the second arm, and is configured to be capable of applying a pressing force only to the second arm. The displacement enlarging mechanism according to (1). (3) The pressing element is a laminated piezoelectric body, and the piezoelectric body extends through a through hole or a through groove formed in the first arm or the fixed base, and the second arm The displacement enlarging mechanism according to the above (1) or (2), characterized in that it is configured to be able to apply a pressing force only to the pressing force. (4) The displacement enlarging mechanism of (1) is provided in a pair at a symmetrical position with respect to each moving axis of a movable base movable in two orthogonal directions, (1) to (3). The displacement enlarging mechanism according to any one of the first to third aspects. (5) The connection spring has a high rigidity in a moving direction of the moving table and a low rigidity in a direction orthogonal to the moving direction. 2. The displacement enlargement mechanism according to 1. (6) The connection spring has a hollow rectangular shape formed by two sides extending in parallel along the moving direction of the moving table and two sides extending in parallel in a direction orthogonal to the moving spring. The two sides facing each other have the same length as each other, and two sides parallel to the moving direction of the moving table are longer than the other two sides. The displacement enlarging mechanism according to the above (5).

[0043]

According to the present invention, a small displacement magnification mechanism having a large displacement magnification can be provided.

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a displacement magnifying mechanism according to an embodiment of the present invention, and FIG. 1B is a diagram in which a piezoelectric body is inserted into a through hole formed in a first arm. FIG. 3C is a perspective view illustrating a state in which a piezoelectric body is inserted into a through groove formed in the first arm.

FIG. 2A is an analysis model for explaining a relationship between an output displacement of a displacement magnifying mechanism and lengths of first and second arms for determining a size of the displacement magnifying mechanism; An analysis model in a state where a pressing force of the piezoelectric body is applied to a pressing point of the second arm.

FIG. 3 shows characteristics of output displacement with respect to arm length of a conventional displacement magnifying mechanism, and first and second displacement magnifying mechanisms of the present invention.
FIG. 4 is a diagram showing a relationship between the length of an arm and the characteristic of output displacement.

FIG. 4 is a diagram showing a configuration of a displacement enlarging mechanism according to a first modification of the present invention.

FIG. 5 is a diagram showing a configuration of a displacement enlarging mechanism according to a second modified example of the present invention.

FIG. 6 is a diagram showing a configuration of a conventional displacement enlarging mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Displacement enlargement mechanism 18 Fixed base 20 Fixed base 22 Moving base 24 First arm 26 Connection spring 28 Second arm 30 Parallel spring 42 Piezoelectric body 44 Through hole 46 Through groove

Claims (3)

[Claims] 1. A fixed base that can be integrally attached to a fixed base, a movable base that is elastically supported via an elastic support member, and a first arm that has one end supported by the fixed base. A connection spring for connecting the other end of the first arm and the movable table, a second arm having one end supported by the fixed table and extending parallel to the first arm; Connecting means for connecting the second arm with the second arm; and a pressing element for applying a pressing force to the second arm from a direction perpendicular to the extending direction of the second arm. A displacement enlarging mechanism, characterized in that: 2. The device according to claim 1, wherein the pressing element extends from the first arm side toward the second arm, and is configured to apply a pressing force only to the second arm. The displacement enlarging mechanism according to claim 1. 3. The pressing element is a laminated piezoelectric body, and the piezoelectric body extends through a through-hole or a through-groove formed in the first arm or the fixed base, and The displacement enlarging mechanism according to claim 1, wherein a pressing force can be applied only to the arm.