JPH0677217B2 - Fine displacement mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fine displacement mechanism for adjusting fine displacement in the fields of semiconductor manufacturing and inspection, high magnification microscopes and the like.

[Conventional technology]

In the fields of semiconductor manufacturing and inspection, high-power microscopes, and the like, a fine displacement mechanism that accurately obtains a fine displacement of several microns or less is necessary. Such a fine displacement mechanism is disclosed in, for example, JP-A-61-209846 and JP-A-61-2435.
It is proposed by the publication No. 11, etc. This will be described below with reference to the drawings.

FIGS. 5 (a) and 5 (b) are side views of a subtle flat displacement mechanism. Of these, FIG. 5 (a) shows a fine displacement mechanism for translational displacement, and 1 and 2 are rigid body parts facing each other and 3
Are two flat plates connecting the rigid bodies 1 and 2. The flat plates 3 are arranged in parallel with each other. These two rigid parts 1,2
The flexible structure 4 is composed of the two flat plates 3. In the actual manufacturing, the flexible structure 4 is formed by forming the through hole 5 in one rigid block. 6
Is a displacement generating element mounted between two protrusions protruding from the rigid body portions 1 and 2 into the through hole 5, respectively. Since a piezoelectric element is often used as the displacement generating element 5,
Hereinafter, the displacement generating element is represented by a piezoelectric element. Rigid part 1
When the piezoelectric element 6 is fixed and excited, the respective flat plates 3 are deformed as shown by broken lines (however, this deformation is exaggeratedly drawn), and the rigid body portion 2 is translationally displaced with respect to the rigid body portion 1. You can

FIG. 5 (b) shows a fine displacement mechanism for rotational displacement.
Reference numeral 2 is a rigid body portion, and 13 is two flat plates connecting the rigid body portions 11 and 12. The flat plates 13 are arranged radially with respect to an axis O perpendicular to the plane of the drawing. Two rigid parts 11,12, two flat plates 1
The flexible structure 14 is composed of 3. Reference numeral 15 is a trapezoidal through hole for forming the flexible structure 14. 16 is a rigid body part
The piezoelectric element is mounted between two protrusions protruding from the insides of the through holes 15 from 11, 12 respectively. When the rigid body portion 11 is fixed and the piezoelectric element 16 is excited, each flat plate 13 is deformed as shown by the broken line (exaggeratedly drawn), and the rigid body portion 12 is deformed with respect to the rigid body portion 11.
Can be rotationally displaced.

By combining the flexible structures 4 shown in FIG. 5 (a) in a complicated manner, translational displacement in an arbitrary direction can be obtained, and by combining a plurality of flexible structures 14 shown in FIG. 5 (b). By combining the arbitrary rotational displacement and the flexible structure 4 and the flexible structure 14, an arbitrary translational displacement and an arbitrary rotational displacement can be simultaneously obtained.

6 (a) and 6 (b) are side views of another conventional fine displacement mechanism. This fine displacement mechanism is shown in FIGS. 5 (a) and 5 (b).
While the fine displacement mechanism shown in (1) has a configuration that utilizes the deformation of the flat plates 3 and 13 itself, it has a configuration that utilizes the deformation of the elastic hinge. Therefore, first, the outline of the elastic hinge will be described with reference to FIGS.

FIG. 7 (a) is a side view of the elastic hinge. Reference numeral 17 is one rigid member, and 18 is a substantially arcuate notch formed facing the intermediate portion of the rigid member 17. A narrow portion 19 is formed in the rigid member 17 by the notches 18, and the rigid member 17 is narrowed by the narrow portion 19.
Thus, it is divided into rigid body portions 17a and 17b connected to this.

FIG. 7 (b) is a side view of another elastic hinge. In the figure, the same parts as those shown in FIG. 7 (a) are designated by the same reference numerals. 19 'is a narrow space. The narrow portion 19 ′ is formed by one substantially arcuate notch 18, while the narrow portion 19 is formed by the two notches 18 facing each other.

FIG. 7 (c) is an operation explanatory view of the elastic hinge. In the figure,
Reference numerals 17a and 17b denote the same rigid portions as those shown in FIGS. 7A and 7B, and 20 denotes a hinge point that rotatably connects the rigid portions 17a and 17b.

Now, in FIGS. 7A and 7B, one rigid body portion 17a
Is fixed and a force F in the direction of the arrow in the figure is applied to the other rigid body portion 17b, the rigid body portions 17a and 17b are hardly deformed,
The narrow portions 19 and 19 'are slightly deformed, whereby the rigid body portion 17b is rotationally displaced as shown by the broken line. However, when a force component in a direction other than the force F acts, the narrow portion 19,1
9'has the characteristic of being extremely resistant to deformation. The above characteristics are the same as those of the configuration in which two rigid body portions 17a and 17b are connected at the hinge point 20 as shown in FIG. 7C, within the range of elastic deformation of the narrow portions 19 and 19 '. The narrow portions 19, 19 'are referred to as elastic hinges because they have similar characteristics.

By the way, since the hinge point 20 shown in FIG. 7 (c) is formed by fitting of mechanical parts, even if those mechanical parts are processed with the highest precision, it is not possible to avoid the existence of micron-level gaps. Can not. Therefore, it is impossible for the hinge point 20 to generate an error-free displacement when performing a very small displacement. On the other hand, the elastic hinge composed of the narrow portions 19 and 19 'exhibits almost no displacement error within the range of elastic deformation and exhibits ideal hinge characteristics.

In the fine displacement mechanism shown in FIGS. 6 (a) and 6 (b), a flat rigid body having elastic hinges at both ends is used instead of the flat plates 3 and 13 of the fine displacement mechanism shown in FIGS. 5 (a) and 5 (b). To be In FIGS. 6A and 6B, the same parts as those shown in FIGS. 5A and 5B are designated by the same reference numerals. Reference numerals 21 and 31 denote rigid plates, and reference numerals 22 and 32 denote elastic hinges formed by the notches 23 and 33. In this case, the rigid body portions 17a and 17b shown in FIGS. 7A to 7C are the rigid body portions 1 and 11 and the plate-like rigid body portions 21 and 31, or the rigid body portions 2 and 12 and the flat plate-like rigid bodies 21 and 31, respectively. Clearly the equivalent. 24 and 34 are such flat plate-like rigid parts 21 and 31, elastic hinges.
A flexible structure using 22,32 is shown.

These fine displacement mechanisms excite the piezoelectric elements 6 and 16 to cause translational displacement and rotational displacement in the rigid body portions 2 and 12, respectively, as indicated by broken lines. The reason why such displacement occurs is considered to be clear from the description of the elastic hinge described above, and thus the description thereof is omitted. It is also clear that any desired displacement can be obtained by using a plurality of these fine displacement mechanisms or using them in combination.

In the fine displacement mechanism shown in FIGS. 6A and 6B, the deformation occurs only in the elastic hinges 22 and 32, and not in the flat plate rigid bodies 21 and 31. Therefore, the flat plate rigid bodies 21 and 31 do not have to be flat plate-shaped, and may have any shape as long as they are rigid bodies. Since such a rigid body constitutes a link mechanism together with an elastic hinge, it can be generally referred to as a rigid body link.

[Problems to be Solved by the Invention]

Each of the fine displacement mechanisms described above can generate displacement with high accuracy. However, the magnitude of the displacement obtained by them is at the same level as the displacement generated in the piezoelectric elements 6 and 16, and it is in the range of several microns to ten and several microns at most. Incidentally, some devices using the fine displacement mechanism require a maximum displacement of several tens of microns to several hundreds of microns. In this case, the above-mentioned fine displacement mechanism cannot obtain such a large displacement. . Therefore, conventionally, in order to obtain a large displacement, after a large displacement is generated by an appropriate coarse displacement mechanism, a highly accurate displacement is obtained using the fine displacement mechanism, or a displacement in the same direction is generated. Means such as stacking the fine displacement mechanisms in a plurality of stages has been adopted.

However, these means have to use a plurality of displacement mechanisms in any case, which causes a problem that the device becomes large and complicated, and it is difficult and expensive to manufacture.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a fine displacement mechanism capable of obtaining a large output displacement by itself.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a first rigid body portion, a second rigid body portion, a plurality of flexible beams or a plurality of coupling rigid body links that couple these rigid body portions, and the rigid body portions. In a fine displacement mechanism having a displacement generating element for generating a relative displacement between the displacement generating element, the driving direction does not match the direction of the relative displacement, and 90 degrees to this direction. It is characterized in that the rigid bodies are connected to each other through elastic hinges so as to form a predetermined angle other than the above.

[Operation] When the displacement generating element is excited, the displacement generating element pushes one rigid body portion via the elastic hinge. At this time, the displacement amount of the displacement generating element is expanded because the displacement generating element is fixed between the rigid body portions at a predetermined angle (except 90 degrees) with respect to the displacement direction of the one rigid body portion. As a result, a relatively enlarged displacement is generated between the first rigid body portion and the second rigid body portion.

〔Example〕

 Hereinafter, the present invention will be described based on the illustrated embodiments.

FIG. 1 is a side view of the fine displacement mechanism according to the first embodiment of the present invention. In the figure, the same or equivalent parts as those shown in FIG. 6 (a) are designated by the same reference numerals and the description thereof will be omitted. 1a, 2
Reference characters a are recesses formed in the rigid portions 1 and 2 respectively continuous with the through holes 5 and are formed at positions deviated from each other. The piezoelectric element 6 is recessed, and is installed with its both ends inserted in 1a and 2a. As a result, the piezoelectric element 6 is mounted between the rigid body portions 1 and 2 at an angle (excluding 90 degrees) with respect to the displacement direction of the rigid body portion 2 (direction of arrow D). . Reference numerals 40a and 40b respectively denote elastic hinges, and the reference numerals in parentheses attached to the reference numerals indicate the names attached to the deformation center points of the elastic hinges. Reference numerals 41a and 41b denote supporting rigid bodies that are connected to both ends of the piezoelectric element 6 to support it. The piezoelectric element 6 is installed at a predetermined angle (θ) with respect to the length direction of the flat plate 3 as shown in the figure. One end of the piezoelectric element 6 is a supporting rigid body
41b is connected to the rigid body portion 1 via the elastic hinge 40b, and the other end of the piezoelectric element 6 is connected to the rigid body portion 2 via the supporting rigid body 41a and the elastic hinge 40a.

Next, the operation of this embodiment will be described. When a voltage is applied to the piezoelectric element 6, the piezoelectric element 6 expands in proportion to this voltage. This extension is allowed only because the elastic hinge 40b rotates counterclockwise and the point Q of the elastic hinge 40a is displaced in the direction of arrow D because the rigidity in the extending direction is high. Here, E is the intersection of a line segment passing through the point P and parallel to the length direction of the flat plate 3 (one-dot chain line) and a line segment passing through the point Q and perpendicular to the length direction of the flat plate 3 (one-dot chain line). , The length of line segment ▲ ▼ is l ₁ ,
When the length of the component ▲ ▼ is l ₂ and the length of the component ▲ ▼ is l ₃ , the following equation holds.

l ₃ ² ＝ l ₁ ² ＋ l ₂ ² …………… (1) Differentiating both sides of the equation (1), 2l ₃ · dl ₃ = 2l ₁ dl ₁ + 2l ₂ dl ₂ … (2) (2) ), Dl ₃ , dl ₁ and dl ₂ mean the increments of the respective line segments, but since the increment of the line segment l ₁ is 0 even if the piezoelectric element 6 expands, the equation (2) becomes Becomes In the equation (3), dl ₂ is the amount of movement of the point Q in the direction of the arrow D, and dl ₃ is the amount of extension of the piezoelectric element 6. Therefore, if the amount of expansion of the piezoelectric element 6 is δ and the amount of displacement of the point Q is δ ′, from equation (3), Becomes That is, the expansion amount of the piezoelectric element 6 is expanded by 1 / sin θ and transmitted to the rigid body portion 2, and the rigid body portion 2 is largely displaced.

As described above, in this embodiment, since the piezoelectric element is installed with a predetermined angle between the rigid body portions via the elastic hinge,
A large translational displacement can be obtained with a simple structure.

FIG. 2 is a side view of the fine displacement mechanism according to the second embodiment of the present invention. In the figure, the same or equivalent parts as those shown in FIGS. 1 and 6 (a) are designated by the same reference numerals and the description thereof will be omitted. The difference between this embodiment and the first embodiment is that
Whereas the first embodiment is a flexible structure composed of the flat plate 3 shown in FIG. 5 (a), the flexible structure of the present embodiment is shown in FIG. It is only a flexible structure made of a rigid body 21. The operation and effect of the translational displacement of this embodiment are the same as those of the first embodiment. The plate-shaped rigid body 21 may be of any shape as long as it is rigid.

FIG. 3 is a side view of the fine displacement mechanism according to the third embodiment of the present invention. In the figure, parts that are the same as or equivalent to those shown in FIG. 6 (b) are assigned the same reference numerals and explanations thereof are omitted. 11a,
Reference numerals 12a are recesses formed in the rigid portions 11 and 12 respectively continuous with the through hole 15, and are formed at positions displaced from each other.
The piezoelectric element 16 is installed with both ends inserted in the recesses 11a and 12a. 50a and 50b are elastic hinges,
The reference numeral in parentheses attached to each of these reference numerals indicates the name given to the deformation center point of the elastic hinge. 51a and 51b are piezoelectric elements 1
It is a supporting rigid body that is connected to both ends of 6 and supports it. The piezoelectric element 16 is installed at a predetermined angle with respect to the length direction of the flat plate 13. One end of the piezoelectric element 16 is connected to the rigid body portion 11 via the supporting rigid body 51b and the elastic hinge 50b, and the other end of the piezoelectric element 16 is connected to the supporting rigid body 51a and the elastic hinge 50a to form a plate-shaped rigid body 31.
Is connected to the connecting surface 31b.

As is apparent from the figure, the present embodiment is different only in that the first embodiment is a fine displacement mechanism for translational displacement, whereas it is a fine displacement mechanism for rotational displacement. That is, the recesses 11a and 12a, the elastic hinges 50a and 50b, and the supporting rigid bodies 51a and 51 of this embodiment.
b corresponds to the recesses 1a and 2a, the elastic hinges 40a and 40b, and the supporting rigid bodies 41a and 41b in the first embodiment, respectively. And, it is clear that the operation and displacement magnifying function of this embodiment are similar to the operation and displacement magnifying function of the first embodiment, which makes it possible for this embodiment to obtain a large rotational displacement with a simple structure. it can.

FIG. 4 is a side view of the fine displacement mechanism according to the fourth embodiment of the present invention. In the figure, parts that are the same as or equivalent to those shown in FIGS. 3 and 6 (b) are assigned the same reference numerals and explanations thereof are omitted. The present embodiment differs from the third embodiment described above in that the third embodiment is a flexible structure made of a flat plate 13 shown in FIG. The only thing is that it is a flexible structure comprising an elastic hinge 32 and a plate-shaped rigid body 31 shown in FIG. 6 (b). The operation and effect of the rotational displacement of this embodiment are the same as those of the third embodiment. The plate-shaped rigid body 31 may be of any shape as long as it is rigid.

〔The invention's effect〕

As described above, according to the present invention, the displacement generating element is connected between the steel body portions via the elastic hinge, and the displacement direction thereof is at a predetermined angle with respect to the displacement direction of the rigid body portion except 90 degrees. Therefore, the displacement of the displacement generating element can be increased,
A large displacement can be obtained with a simple structure.

[Brief description of drawings]

1, FIG. 2, FIG. 3, and FIG. 4 are side views of the fine displacement mechanism according to the first, second, third, and fourth embodiments of the present invention, respectively, and FIG. 3 (a), (B), FIG. 6 (a) and (b) are side views of the conventional fine displacement mechanism, and FIG. 7 (a), respectively.
7B is a side view of the elastic hinge, and FIG. 7C is an operation explanatory view of the elastic hinge. 1,2,11,12, ... Rigid part, 1a, 2a, 11a, 12a ... Dent, 3,13
...... Plate, 6,16, ... Piezoelectric element, 21,31, ... Plate rigid body, 22,32,40a, 40b, 50a, 50b …… Elastic hinge, 41a, 41b, 5
1a, 51b …… Supporting rigid body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Nagasawa 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.Tsuchiura factory (72) Inventor Ken Murayama 650 Jinmachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Ceremony Company Tsuchiura Factory (56) Reference JP-A-62-64276 (JP, A)

Claims (7)

[Claims] 1. A first rigid body portion, a second rigid body portion, a plurality of flexible beams connecting these rigid body portions, and a displacement generating element for generating relative displacement between the rigid body portions. In the fine displacement mechanism, the displacement generating element is arranged between the rigid body parts such that the driving direction of the displacement generating element does not coincide with the relative displacement direction and is at a predetermined angle outside this direction by 90 degrees. A fine displacement mechanism, characterized in that it is connected to the shaft via an elastic hinge. 2. A fine displacement mechanism according to claim 1, wherein the flexible beams are arranged in parallel with each other. 3. A fine displacement mechanism according to claim (1), wherein each of the flexible beams is arranged radially with respect to a predetermined point. 4. A first rigid body portion, a second rigid body portion, a plurality of coupling rigid body links for coupling these rigid body portions, and a displacement generating element for generating relative displacement between the rigid body portions. In the fine displacement mechanism including, the displacement generating element, the driving direction does not match the direction of the relative displacement, and each rigid body such that the predetermined direction other than 90 degrees to this direction Fine displacement mechanism characterized by being connected via elastic hinges between parts 5. The fine displacement mechanism according to claim (4), wherein the connecting rigid links are arranged in parallel with each other. 6. The fine displacement mechanism according to claim (4), wherein each of the connecting rigid links is arranged radially with respect to a predetermined point. 7. The displacement generating element according to claim 1 or 4, wherein the displacement generating element is a region formed by a space where the first rigid body portion and the second rigid body portion face each other. A fine displacement mechanism characterized by being arranged inside.