JPH10186198A - Parallel and straight fine adjustment device and fine moving device of lens barrel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parallel and straight fine adjustment device which is excellent in parallelism and straightness with respect to movement, whose structure is simple and which is produced at low cost. SOLUTION: An internal lens barrel 5 is connected to the ends of three pairs of parallel springs 7a1-7b1, 7a2-(7b2), 7a3-7b3 having the same shape and made of the same material, and a lens barrel 1 is connected to the other ends of three pairs of parallel springs. Then, the parallel springs are attached in a state where they have no deflection, and arranged on a plane perpendicular to the optical axis of the lens of the lens barrel 5 so that synthetic force obtained by synthesizing force generated respectively in the parallel springs when the lens barrel 5 is moved may be zero. When the bottom part of the lens barrel 5 is pressed by a lever member 4 by operating a micrometer 3, the lens barrel 5 rises. However, at such a time, the same tensile force is exerted on the respective parallel springs and the synthetic force thereof becomes zero, then the lens barrel 5 is moved straight and in parallel with the optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel / straight fine movement device using a spring guide used for an optical device such as an exposure machine, various precision processing machines, various precision measuring devices and the like, and a lens barrel using the same. A small moving device.

[0002]

2. Description of the Related Art Optical devices such as exposure machines, various precision processing machines,
2. Description of the Related Art In various precision measuring instruments, it is required to position a lens, a work, a workpiece, and a workpiece with high accuracy. There are various types of moving mechanisms that satisfy such requirements,
Spring guides are widely used. The spring guide operates without backlash because it has no frictional resistance due to sliding or rolling, and has the advantages of extremely high accuracy and reproducibility, simple maintenance, easy maintenance, and low manufacturing costs. .

[0003] As a moving mechanism using the above-described spring guide, the following is conventionally known. Moving mechanism using parallel spring (No. 1) FIG. 5 is a view showing an example of a moving mechanism using a parallel spring, where 10 is a base, 11 is a moving body, and the moving body 11 is fixed to the base 10. It is attached by two parallel leaf springs b1 and b2. In this figure, when the moving body 11 is moved in the direction of the arrow shown in the figure, the leaf springs b1 and b2 bend from the state shown in FIG. Move in parallel.

The moving mechanism can move the moving body 11 in parallel as described above, but when the moving body 11 moves downward, as shown in FIG. Go to That is, the above-mentioned moving mechanism cannot obtain the straight movement even though the parallel movement is obtained.
For a displacement I of 1, a lateral displacement (Δ
L) occurs. For this reason, the above mechanism is highly accurate
It is not suitable as a guide for straight travel.

Moving Mechanism Using Parallel Springs (Part 2) As a moving mechanism capable of canceling the lateral displacement of the moving body 11, a mechanism shown in FIG. 6 using four leaf springs of the same shape and the same material is used. It has been known. In FIG. 1, one end of two parallel leaf springs b1 and b3 is fixed to the base 10, and the other end of the leaf springs b1 and b3 is attached to the intermediate moving body 12. Further, one end of two parallel leaf springs b2 and b4 is fixed to the intermediate moving body 12, and the other end is attached to the moving body 11.

In the figure, when the moving body 11 is moved in the direction of the arrow in the figure, the parallel springs b2 and b4 bend, and the moving body 11 tries to move ΔL to the left in the figure. On the other hand, a leaf spring b1, provided between the intermediate moving body 12 and the base 10,
b3 also bends by the same amount, and the intermediate moving body 12 attempts to move by ΔL to the right in FIG. Eventually, the movement in the left-right direction is canceled out, and theoretically the moving body 11 moves parallel to the base 10. With this mechanism, parallel / straight motion is theoretically established, and the movement range can be widened. However, in actuality, the leaf spring b
1 to b4 other than natural bending, tension, compression, inclination,
When a force such as torsion is applied, the leaf springs b1 to b4 bend in a complicated manner, and the moving body 11 does not necessarily move in parallel or straight.

A moving mechanism using a pair of leaf springs A method shown in FIG. 7 is known as a method for realizing accurate parallel / straight movement without using the above-mentioned parallel springs.
As shown in the figure, a pair of leaf springs b
The other ends of the leaf springs b1 and b2 are fixed to a leaf spring support 13 attached to the base 10. Then, a driving body such as a wedge is provided at at least three places between the moving body 11 and the base 10, and a driving force is applied to the moving body 11 in the direction of the arrow in FIG. In the above-described mechanism, the moving body 11 can be moved in parallel and straight if the driving forces of the driving bodies provided at three locations are made perpendicular and equal to the plane of the moving body.

In the above-described device, two leaf springs b
Assuming that the tension inside the leaf springs b1 and b2 when the planes 1 and b2 are in one plane is 0, the leaf springs b1 and b2 are slightly extended by the movement of the moving body 11, and a tension is generated inside. In such an apparatus, the moving body 11 is
It is necessary to be configured to move within the elastic limit of 1, b2. With the above configuration, the moving body 11 can be parallelized with high accuracy.
Although straight motion can be realized, each driving force of the driving bodies provided at the above three places must be perpendicular and equal to the plane of the moving body, and when this is realized by a wedge or the like, Requires high processing accuracy and assembly accuracy.

[0009]

As described above, the above-described moving mechanism can move the moving body in parallel, but cannot obtain straight movement, and the moving mechanism is theoretically impossible. Can move in parallel and straight, but in reality, the leaf spring is flexed complicatedly by the force of vibration or the like applied to the moving body, so that parallel / straight movement cannot always be obtained. Further, if the above moving mechanism is used, parallel / straight motion can be obtained with relatively high accuracy. However, the driving mechanism for driving the moving body becomes complicated, and high accuracy is required for machining and assembly. is there.

The present invention has been made in consideration of the above-mentioned problems of the prior art, and a first object of the present invention is to provide good parallelism and straightness with respect to movement, no backlash, and high reproducibility. Another object of the present invention is to provide a parallel / straight fine movement device which has a simple structure and can be manufactured at low cost. A second object of the present invention is to provide a lens (or lens group) that can be finely moved in parallel and with good straightness, has good reproducibility without backlash, has a simple structure, and can be manufactured at low cost. An object of the present invention is to provide a micro-movement device for a lens barrel.

[0011]

Means for Solving the Problems The above-mentioned problems are solved in the present invention as follows. (1) Three or more sets of parallel springs made of the same material with the same shape, a moving member to which one end of each of the three or more sets of parallel springs is connected, and another end of each of the three or more sets of parallel springs connected A parallel / straight fine movement device is constructed from the fixed member thus mounted, and each of the parallel springs is mounted between the moving member and the fixed member without bending, and is positioned on a plane perpendicular to the moving direction of the moving member. The parallel springs are arranged such that the resultant force of the respective forces generated when the moving member moves is zero. (2) In the above (1), the parallel springs are arranged such that the intersection of the center axes of the respective parallel springs in the bending direction is on a specific movement axis of the moving member, and the angles formed by the respective center axes are equal. To place.

(3) Three or more sets of parallel springs of the same shape and made of the same material, a lens barrel to which one end of the three or more sets of parallel springs are connected, and the three sets of parallel springs arranged in the lens barrel. An inner barrel to which the other end of the parallel spring is connected, a lens disposed in the inner barrel, and a drive for generating a driving force for moving the inner barrel in the optical axis direction of the lens. A micro-moving device for the lens barrel from the means, and each of the parallel springs is mounted between the barrel and the inner barrel in a state without bending, and a plane perpendicular to the optical axis of the lens of the inner barrel. It is arranged on the upper side so that the resultant force of the forces generated in the parallel springs when the inner lens barrel moves is zero.

According to the first and second aspects of the present invention,
With the configuration as described in (1) and (2) above, when the moving member is moved, the same tensile force is applied to each parallel spring and the combined force becomes zero, so that the moving body can be moved in parallel and straight. . According to the third aspect of the present invention, since the inner barrel is moved by the driving means, the same tensile force is applied to the parallel springs as in the above case when the inner barrel is moved by the driving means. The force becomes zero, and the inner lens barrel can be moved straight and parallel to the optical axis.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing an embodiment in which the present invention is applied to a micro-moving device for a lens barrel used in a projection exposure apparatus for semiconductor manufacturing and the like, and FIG. Figure,
FIG. 2B is a cross-sectional view in the direction A in FIG. In FIG. 1, reference numeral 1 denotes a lens barrel, 5 denotes an internal lens barrel, and a lens group 2 is mounted inside the internal lens barrel 5. For example, the projection magnification and the like are adjusted by slightly moving in the vertical direction. The same shape, between the inner barrel 5 and the inner convex portion 6 of the barrel 1,
6 leaf springs 7a1-7a3, 7b1-7b3 of the same material
The leaf springs 7a1 and 7b1, the leaf spring 7a
2 and 7b2 and the leaf springs 7a3 and 7b3 constitute a parallel spring. These parallel springs 7a1, 7b1, 7a2, 7
In b2, 7a3, and 7b3, the center axes of the respective bending directions are equally spaced around the optical axis of the lens group 2 (in this case, 1).
20 °).

Reference numeral 3 denotes a micrometer, and reference numeral 4 denotes a lever member. The lever member 4 is supported by a mounting member 8 and rotates about its axis. Further, the point P1 of the lever member 4 is in contact with the movable portion 3a of the micrometer 3, and the point P2 is in contact with the bottom of the inner lens barrel 5. Therefore, when the micrometer 3 is rotated in the direction in which the movable portion 3a projects, the point P1 of the lever member 4 is pushed, the lever member 4 rotates, and the point P2 of the lever member 4 The bottom is pushed to push up the inner lens barrel 5. Here, when only the parallel springs 7a1 and 7b1 are connected between the lens barrel 1 and the internal lens barrel 5, when the internal lens barrel 5 is pushed upward, as shown in FIG. 5 attempts to move toward the lens barrel 1 by ΔL. However, since the parallel springs 7a2 and 7b2 and 7a3 and 7b3 are provided between the lens barrel 1 and the internal lens barrel 5, the internal lens barrel 5 is Cannot be moved as shown in FIG.
A force f shown in FIG. 1A acts on 7b3.

Each parallel spring 7a1 and 7b1, 7a2 and 7b
2, 7a3 and 7b3 are made of leaf springs of the same shape and the same material, and the parallel springs are arranged at equal intervals (120 ° intervals) as shown in FIG.
Its combined power balances. That is, each parallel spring 7a1
When the forces generated at 7b1 and 7a2, 7b2 and 7a3 and 7b3 are regarded as vectors, the combined vector becomes 0 and is balanced. Then, an equal tension is applied to each parallel spring to slightly expand it, and the inner lens barrel 5 moves straight and parallel to the optical axis.

When the optical axis is in the direction of gravity, a moment is applied to the external force applied to the inner lens barrel 5 depending on the weight of the inner lens barrel 5 on the optical axis and the position of the driving point to the inner lens barrel 5. The combined forces of various flexures are applied to the parallel springs 7a1 to 7b3. However, since each leaf spring of each parallel spring is on one plane, if one tries to extend,
The other side is repelled by the contracting force, so that the parallelism of the inner lens barrel 5 is not lost. Even if a torsional force is applied to one parallel spring, it is supported by another parallel spring.

In order to check the straightness of the micro-movement device having the above-described structure, the device shown in FIG. 1 was assembled using the parallel spring shown in FIG. 2 and the straightness of the inner lens barrel 5 was checked. The material of the leaf spring used in the above experiment was SKS-CSPH, the thickness of the leaf spring was 0.3 mmt, and as shown in FIG. 2, the width of the leaf spring was 26 mm, the interval between the leaf springs was 140 mm, The parallel springs having a length of 40 mm were formed at intervals of 120 ° as shown in FIG. In the above configuration, when the inner lens barrel 5 was moved by ± 0.5 mm in the optical axis direction, it was confirmed that the inner lens barrel 5 moved with a straightness of 0.5 μm or less, and required accuracy could be secured. As described above, in this embodiment, since the parallel springs 7a1 to 7b3 of the same shape and the same material are arranged at equal intervals between the lens barrel 1 and the inner lens barrel 5, the inner lens barrel 5 is moved with respect to the optical axis. It can be moved straight and parallel. Further, since the parallel spring is used, the inner barrel 5 can be finely moved with good reproducibility without causing backlash.

In the above embodiment, three sets of parallel springs
Although the case where the parallel springs are arranged is shown, the number and arrangement of the parallel springs are not limited to the above embodiment, and three or more parallel springs are set so that the sum of the force vectors acting on the parallel springs becomes zero. A similar effect can be obtained by disposing a spring. Further, in the above embodiment, the central axis of the width in the bending direction of each parallel spring is configured to be directed to the optical axis, but the direction in which the central axis of each parallel spring is directed does not necessarily need to be the optical axis.
Any axis may be used as long as the axis is parallel to the moving direction of the moving body. 3 and 4
FIG. 7 is a view showing another example of arrangement of parallel springs. FIG.
(A) and (b) show the case where four sets of parallel springs are symmetrically arranged around a specific axis, and the directions of the force vectors acting on the parallel springs at that time are shown in FIGS. Become like

Further, the specific axis may be plural, and if the combined force of the tensile force of the parallel springs applied to the specific axis in the moving body is made to be zero as a whole, the same as the above is obtained. The effect can be obtained. That is, FIG.
(A) As shown in (b), six or four sets of parallel springs are used, and the combined force of their tensile forces is shown in FIG.
What is necessary is just to comprise so that it may become 0 as a whole as shown to (d). As shown in FIGS. 3 and 4, when three or more sets of parallel springs are used, the force withstanding deformation as a whole increases, and the rigidity increases as the number of parallel springs increases.
However, if the number of parallel springs is excessively increased, it becomes difficult to maintain the accuracy. Therefore, the number of parallel springs is optimally n = 3 in terms of machining and assembly.

[0021]

As described above, in the present invention, three or more sets of parallel springs of the same shape and made of the same material, a moving member to which one end of each of the three sets of parallel springs is connected, A parallel / straight fine movement device is constituted by a fixed member to which the other end of each of the three or more parallel springs is connected, and each of the parallel springs is attached between the moving member and the fixed member without bending, respectively. Since the components are arranged on a plane perpendicular to the moving direction of the moving member so that the resultant force of the forces generated in the parallel springs when the moving member moves becomes zero, the following effects can be obtained. (1) The parallelism is high, there is no backlash, and the moving body can be finely moved with good reproducibility. In addition, it is possible to realize a movement with good straightness and high rigidity.

(2) Since the moving member can be moved in parallel and straight by three or more sets of parallel springs, a simple mechanism can be used as a driving means for moving the moving body, and the manufacturing cost of the apparatus can be reduced. It is possible to reduce the size and improve the maintainability. (3) By applying the fine movement device to a fine movement device of a lens barrel, the lens can be moved straight and parallel along the optical axis, and the projection magnification and the like can be adjusted with high precision. Also, the drive mechanism for moving the lens is
A simple mechanism such as a lever can be used, the manufacturing cost can be reduced, and the maintainability can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a fine movement device of a lens barrel according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a parallel spring used for checking the straightness of the fine movement mechanism according to the embodiment of the present invention.

FIG. 3 is a diagram showing another configuration example of the fine movement device according to the embodiment of the present invention.

FIG. 4 is a diagram showing another configuration example of the fine movement device according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a moving mechanism using a parallel spring.

FIG. 6 is a diagram showing an example of a moving mechanism using a parallel spring capable of canceling a lateral displacement of a moving body.

FIG. 7 is a diagram illustrating an example of a moving mechanism using a pair of leaf springs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens barrel 2 Lens group 3 Micrometer 4 Lever member 5 Internal convex part of internal barrel 6 7a1, 7b1 Parallel spring 7a2, 7b2 Parallel spring 7a3, 7b3 Parallel spring 8 Mounting member

Claims (3)

[Claims] 1. Three or more sets of parallel springs having the same shape and made of the same material, a moving member to which one end of each of the three or more sets of parallel springs is connected, and the other end of each of the three or more sets of parallel springs The parallel springs are respectively mounted without bending, and the parallel springs are on a plane perpendicular to the moving direction of the moving member, and the moving member has moved. A parallel / straight fine movement device characterized by being arranged such that the resultant force of the forces generated in each of the parallel springs sometimes becomes zero. 2. The parallel spring according to claim 1, wherein the intersection of the central axes in the bending direction of the parallel springs is on a specific moving axis of the moving member, and the angles formed by the central axes are equal. 1 parallel / straight fine movement device. 3. At least three sets of parallel springs of the same shape and made of the same material; a lens barrel to which one end of the three or more sets of parallel springs is connected; An inner barrel to which the other end of the parallel spring is connected, a lens disposed in the inner barrel, and driving means for generating a driving force for moving the inner barrel in the optical axis direction of the lens. Wherein each of the parallel springs is attached between the barrel and the inner barrel in a state without bending, and is on a plane perpendicular to the optical axis of the lens of the inner barrel, and the inner barrel is Wherein the combined force of the forces generated by the parallel springs when the lens is moved is zero.