JPH0915474A - Optical element holding device - Google Patents

Abstract

PURPOSE: To maintain and improve the arranging accuracy of an optical element by making plural flexible parts arranged under a holding means communicate each other, sealing fluid in a communicating part, and providing a supporting means arranged between the base of the holding means and the flexible part so that it can move up and down. CONSTITUTION: This optical element holding device 10 is equipped with a disk- like optical surface plate 12, a placing means 14 arranged under the surface plate 12, and supporting parts 16a to 16f provided to be projected at equal intervals on the outer peripheral part of the lower surface of the surface plate 12 and constituting the supporting means. A groove part is formed on the lower surface of the placing means 14, and a ring-like flexible tube 26 is fitted in the groove part. The fluid which is not changed even by pressure load, for example, high-viscocity silicone resin is sealed in the tube 26. Supporting legs 16 are respectively positioned on the upper surface of the tube 26, and the abutting part of the supporting leg 16 on the tube 26 constitutes a flexible part. The fluid pressure in the tube 26 is conducted to other parts and the surface plate 12 is held with equal pressure at many points.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element holding device, and more particularly to a mechanism for preventing the optical element holding plate from bending.

[0002]

2. Description of the Related Art For example, in an optical device such as an interferometer, various optical elements such as a lens system, a half mirror, and a reflecting mirror system are arranged on the optical path. The arrangement accuracy depends directly on the characteristics and accuracy of the optical device. , Indirectly affect. Therefore, the optical element is often arranged on an optical surface plate having high rigidity.
This optical surface plate is generally constructed with a large mass in order to obtain its high rigidity and to improve vibration resistance due to its high inertia.

[0003]

However, recently, an optical device is often used as an inspection device or the like at various processing sites and the like, and a large-mass, high-rigidity optical surface plate prevents the device itself from becoming smaller and lighter. Moreover, it has a big problem that it requires a lot of consideration for installation. Therefore, in order to improve the vibration resistance while reducing the size of the optical surface plate,
It is preferable that the optical surface plate is point-supported on the base.

However, when the optical surface plate is supported by points, it is theoretically inevitably supported by only three points constituting one surface. When the optical surface plate is supported by only three points, the surface plate portion deviating from the surface formed by the three points causes a slight bending, which adversely affects the accuracy of arrangement of the optical system. The present invention has been made in view of the above circumstances, and it is an object of the present invention to support optical element holding means such as an optical surface plate at four or more points to maintain and improve the accuracy of optical element placement. is there.

[0005]

An optical element holding device according to the present invention is a holding means for holding an optical element at a predetermined position, and a holding portion arranged below the holding means. At least four points are flexible portions. Further, the flexible parts communicate with each other, and are arranged between the mounting means in which fluid is sealed in the communication parts, the bottom surface of the holding means, and each flexible part of the mounting means. It is characterized in that it is provided with at least four supporting means that can move up and down. Further, in the present invention, the mounting means includes a frame body having a groove formed on an upper surface thereof, and a ring-shaped flexible tube which is fitted in the groove portion of the frame body and constitutes a communication portion. It is desirable that the upper surface of the flexible tube constitutes a flexible portion.

[0006]

In the optical element holding device according to the present invention, the above-mentioned mounting means enables pressure equalization support at four or more points of the optical element holding means. That is, since each of the plurality of flexible portions of the mounting means is communicated with the communication portion, when a large load is applied to a part of the flexible portion, the flexible portion is dented in a concave shape. , The fluid corresponding to the dent amount is distributed to the flexible portion of the other portion via the communication portion. Therefore, when the optical element holding means is supported by four or more supporting means, when a large load is applied to a part of the supporting means as compared with the other part, the supporting means moves down and the corresponding flexible means is flexed. Presses and makes the concave part concave. Then, the flexible portion of the other portion to which the fluid is distributed is pushed up, and the corresponding support means rises to participate in the support of the optical element holding means.

According to the above operation, according to the optical element holding device of the present invention, it is possible to equalize and support the optical element holding means at four points or more, which is impossible with the rigid-rigid support system.
Bending of the holding means can be prevented. In addition, in the present invention, by configuring the mounting means by the frame body and the ring-shaped tube described above, it is possible to obtain the holding device at a low cost while preventing leakage of the fluid with a simple configuration.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic structure of an optical element holding device according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view thereof. . The optical element holding device 10 according to the present embodiment is a disk-shaped optical surface plate 1 that constitutes a flat plate-shaped holding means.
2, the mounting means 14 arranged below the disc-shaped optical surface plate 12, and the support legs 16a to 1a constituting the support means provided on the outer peripheral portion of the lower surface of the optical surface plate 12 so as to project at equal intervals.
6f (see the top view of the mounting means 14 shown in FIG. 3).

The disc-shaped optical platen 12 holds an optical element (not shown) and is formed to be relatively lightweight and thin. Further, the mounting means 14 is the disk-shaped optical surface plate 12 described above.
And a ring-shaped frame body 18 having a diameter substantially the same as that of the ring-shaped frame body 18 and ring walls 20 and 22 erected concentrically on the outer periphery of the disk-shaped frame body 18, and the gap between the ring walls 20 and 22 forms a groove 24. To do. A ring-shaped tube 26 having excellent flexibility is fitted in the groove 24. In addition, a fluid whose volume does not substantially change even by a pressure load, such as a highly viscous silicone resin 28, is enclosed in the tube 26.

Further, the support legs 16 are respectively located on the upper surface of the tube 26, and the contact portion between the support leg 16 and the tube 26 constitutes a flexible portion. The optical element holding device 10 of the present embodiment is roughly configured as described above, and its operation will be described below. The disk-shaped optical surface plate 12 is the mounting means 1
4 is mounted on the optical surface plate 12 and the tube 2
Assuming that 6 is a rigid body, even though there are six support legs 16 described above, three of them (for example, support legs 16a, 1
6c, 16e). In this case, a large load is applied only to the support legs 16a, 16c, 16e, and as a result, the support legs 16a, 16c of the tube 26 are
The portions corresponding to c and 16e are pressed and deformed into a concave shape.

Since the volume of the fluid in the tube 26 does not change depending on the pressure, the inflation pressure is applied to the other tube portions, and the supporting legs 16b, 16d, 16f rise due to the inflation pressure of the tube 26 to form a disk shape. The optical surface plate 12 is pushed up, and as a result, the weight of the optical surface plate 12 is increased by six support legs 16
It can be supported by a to 16f. Moreover, since the tube internal pressure is uniform in each part, the supporting force by each of the support legs 16a to 16f is also uniform. As described above, according to the optical element holding device 10 of the present embodiment, it is possible to hold the optical surface plate 12 at a plurality of points with equal pressure.

FIG. 4 shows an essential part of an optical element holding device according to a second embodiment of the present invention. The parts corresponding to those in the first embodiment are designated by the reference numeral 100 and will be described. Omit it. In this embodiment, instead of the elastic tube 26 in the first embodiment, ring walls 120 and 122 are used.
A rubber film 126 is coated on the upper part of the ring-shaped wall 12
The fluid 128 is injected into the void 150 formed by the layers 0 and 122 and the film 126. In this case, the holding means 112 has a simpler structure as compared with the device of the first embodiment.
It is possible to support multi-point equalization.

FIG. 5 shows the essential parts of an optical element holding device according to the third embodiment of the present invention. The parts corresponding to those of the first embodiment are designated by the reference numeral 200 for explanation. Omit it. In this embodiment, the ring-shaped walls 220, 22
A cover 260 is provided on the upper surface of the cover 2, and an opening 262 is formed in a portion of the cover 260 corresponding to the support leg 216. As a result, the expansion of the tube 226 is restricted at the portion facing the cover 260, and it becomes concave or convex only at the opening 262 portion, and the substantial vertical movement of the surface plate 212 can be significantly reduced. That is, according to the first embodiment described above, the tube internal pressure changes due to the load fluctuation of the surface plate, and as a result, the tube 226 expands at the portion where the tube 226 and the support leg 216 are not in contact with each other, and the surface plate 212 itself descends. It is possible. However, according to this embodiment, the support leg 21
Since the expansion of the tube 226 is restricted even in the non-contact portion with 6, the vertical movement hardly occurs regardless of the load of the surface plate 212.

FIG. 6 shows the essential parts of an optical element holding device according to a fourth embodiment of the present invention. The parts corresponding to those of the third embodiment are designated by the reference numeral 100 and will be described. Omit it. In the third embodiment, the support legs 216 are fixed to the lower part of the surface plate 212, but in this embodiment, the support legs 316 are separate from the surface plate 312. That is, the support leg 316 of this embodiment is formed in an inverted mushroom shape,
Since the bottom surface 316a having a large area is in contact with the tube 326, the tube 326 (or the film) is not damaged. Moreover, only the upper end 316b of the support leg projects from the opening 362 of the cover 360, and the multi-point equalization support can be performed only by mounting the existing optical surface plate 312 on the mounting means 314. it can.

Further, in the case of the present embodiment, since the volume itself of the tube 326 is regulated, even when compressed air is enclosed in the tube 316, for example, the vertical movement of the surface plate is suppressed and the multi-point equalization support is carried out. Is possible. In each of the above embodiments, a disk-shaped optical surface plate was described as an example of the optical element holding means, but the optical element device of the present invention is not limited to this. The supporting means can be arranged not only on the outer peripheral portion of the surface plate but also on the lower surface of the central portion of the surface plate.

Further, in each of the above-mentioned embodiments, an example in which an optical surface plate is used as the optical element holding device has been described.
For example, it can be applied to a sample placing device at the time of measuring interference fringes. Further, in the present invention, the high-viscosity silicone resin is used as the fluid, but the fluid is not limited to this, and it is also possible to obtain an anti-vibration effect by adjusting the viscosity, for example. Further, not only a fluid in a strict sense, but also a gel-like material or the like can be used.

[Brief description of the drawings]

FIG. 1 is an external view of an optical element holding device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the device according to the first embodiment of the present invention.

FIG. 3 is a top view of mounting means used in the apparatus according to the first embodiment of the present invention.

FIG. 4 is a sectional view of an essential part of an apparatus according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an essential part of an apparatus according to a third embodiment of the present invention.

FIG. 6 is a sectional view of an essential part of an apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

10 Optical element holding device 12, 112, 212, 312 Disc-shaped optical surface plate (holding means) 14, 114, 214, 314 Mounting means 16, 116, 216, 316 Support leg (supporting means) 18, 118, 218, 318 Frame 24,124,224,324 Groove 26,126,226,326 Flexible tube 28,128,228,328 High viscosity silicone resin (fluid)

Claims (2)

[Claims] 1. A holding means for holding an optical element in a predetermined position, and a holding means disposed below the holding means, at least four points being flexible parts, and the flexible parts are in communication with each other. The communication means includes a mounting means in which a fluid is sealed, a bottom surface of the holding means, and at least four vertically movable support means arranged between the flexible portions of the mounting means. An optical element holding device characterized by the above. 2. The apparatus according to claim 1, wherein the mounting means has a frame body having a groove portion formed on an upper surface thereof, and a ring-shaped flexible tube which is fitted into the groove of the frame body and constitutes a communication portion. And an upper surface of the flexible tube constitutes a flexible portion.