JPH10271856A - Mobile stage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile stage usable in a strong magnetic field, and capable of adjusting friction relating to driving easily. SOLUTION: This concerns a mobile stage having a stationary stage 12 and a movable stage 11, using shared piezoelectric elements 15, 17 for its driving, has a leaf spring 14 for applying an attracting force between the stationary stage 12 and the movable stage 11 to bring the movable stage 11 into contact with the stationary stage 12, and the shared piezoelectric elements 15, 17 provided for driving the movable stage 11 at all the contact parts between the stationary stage 12 and the movable stage 11 to be brought into contact with each other by this leaf spring 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic precision moving stage for precisely controlling the position of a target object by an electric signal with an accuracy of, for example, 1 micron or less.

[0002]

2. Description of the Related Art FIG. 3 shows an example of the configuration of a conventional electronic precision moving stage configured using a shear type piezo element. Reference numeral 1 denotes a movable stage, 2 denotes a fixed stage, and 3 denotes a shear type piezo element. A wear-resistant component 4 that contacts the movable stage 1 at one point is fixed to the shear type piezo element 3. The share type piezo element 3 is usually provided at three places, and holds the movable stage 1 at three points. Reference numeral 5 denotes a permanent magnet which is fixed to the fixed stage 2. By making the movable stage 1 of a ferromagnetic material, an attractive force is generated between the movable stage 1 and the fixed stage 2. This attractive force causes a frictional force between the wear-resistant component 4 and the movable stage 1 when the movable stage 1 moves with respect to the fixed stage 2. When a voltage pulse is applied to the shear-type piezo element 3 and the wear-resistant component 4 is moved to the left or right, the movable stage is adjusted by adjusting the voltage waveform so that a force greater than the static friction force is applied to only one of the right and left directions. 1 can be moved in the desired direction. Such a moving stage is commercially available.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and does not use a permanent magnet used in the prior art, and therefore can be used in a strong magnetic field and is involved in driving. It is an object of the present invention to provide a moving stage capable of easily adjusting the frictional force that occurs.

[0004]

In order to achieve the above object, a moving stage according to the present invention has a fixed stage and a movable stage, and uses a shared stage piezo element as driving means for the movable stage. Attraction means for applying an attractive force between the fixed stage and the movable stage by using a spring so that the and the movable stage come into contact with each other, and a shear type provided at all contact portions of the fixed stage and the movable stage contacted by the attraction means. And a driving means using a piezo element.

[0005] The moving stage of the present invention is characterized in that a leaf spring is used as a spring of the attraction means. Further, the moving stage of the present invention is characterized in that a coil spring having a spring length adjusting screw is used as a spring of the attraction means.

In the present invention, a contact-type attractive force applying mechanism using a spring or the like instead of a permanent magnet is used, and an increase in additional friction due to an increase in the number of contact portions is eliminated by introducing a new shear-type piezo element. By doing so, a driving force equal to or higher than that of the related art can be maintained, and further, the ability to adjust the frictional force to an optimum state can be obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram illustrating a first embodiment of the present invention, in which 11 is a movable stage,
Reference numeral 12 denotes a fixed stage, 13 denotes a leaf spring support, 14 denotes a leaf spring, and 15 and 17 denote shear-type piezo elements such as PZT. In this example, a configuration is shown in which the movable stage 11 is moved in the left-right direction in the figure. ing. The moving direction is not limited to this. Numerals 16 and 18 are spheres made of porcelain (for example, SiC), which are fixed to the leaf spring 14 and the shear type piezo element 17, respectively. The spring 14 is fixed to the movable stage 11 by the leaf spring support 13 and generates an attractive force with the fixed stage 12.
The sphere 16 is brought into contact with the fixed stage 12 via the shear type piezo element 15. With such a configuration, when a voltage is applied to the shear-type piezo element 17 to displace the ball 16 with respect to the fixed stage 12, the shear-type piezo element 15 is simultaneously distorted in the same direction as the shear-type piezo element 17. When a voltage is applied so as to cause the friction, the frictional force from the fixed stage 12 that would otherwise be received without the shear type piezo element 15 can be eliminated, and the same operation as a non-contact type attraction mechanism using a magnetic force or the like is performed. be able to. The sum of the static friction forces between the shear type piezo element 15 and the ball 16 is desirably equal to the sum of the static friction forces between the ball 18 and the movable stage 11, but this is not a necessary condition. In the above configuration, the following advantages are obtained because no magnetic force is used for the attraction mechanism. (1) It can be operated under a strong magnetic field. (2) There is no leakage of magnetic flux that affects the load. (3) Movable stage 11
Alternatively, since there is no need to use a magnetic material for the fixed stage 12, a material such as Al suitable for weight reduction can be used freely. In addition, in the configuration as shown in FIG. 1, the size can be reduced to be equal to or more than that of the conventional stage.

FIG. 2 is a view for explaining a second embodiment of the present invention. The movable stage 11, the fixed stage 12, the shear-type piezo element 15, the ball 16, the shear-type piezo element 17, and the ball 18 perform the same functions as the parts with the same numbers in FIG. 13 'is a coil spring fixing mechanism fixed to the movable stage 11, 14' is a coil spring, 19 'is a sapphire plate fixed to the shear type piezo element 15, and 20' is a spring length adjusting screw. The coil spring 14 'is fixed to the movable stage 11 by a coil spring fixing mechanism 13'. The ball 16 is pressed by a coil spring 14 '. The attractive force between the movable stage 11 and the fixed stage 12 is given by a coil spring 14 ', and the attractive force can be adjusted by a spring length adjusting screw 20'. Sapphire board 1
9 'is a sapphire plate inserted for adjusting the frictional force between the piezo element 15 and the ball 16. The operation is the same as that of the embodiment of FIG. 1, but the magnitude of the attractive force can be adjusted by the spring length adjusting screw 20 ', so that the frictional force can be easily adjusted to the optimum state. Further, compared to a leaf spring, the coil spring 14 ′ is less likely to change its spring constant, and thus can operate stably for a long period of time. The sapphire plate 19 'is effective in reducing the frictional force to the operating range of the moving stage when a normal lubrication mechanism does not function effectively, such as in an ultra-high vacuum state or an extremely low temperature state.

As described above, by using the shear type piezo element at the slip point in the mechanical attractive force applying mechanism, the additional frictional force caused by the mechanical contact can be eliminated. The magnet and its associated magnetic material can be removed without compromising the driving force, the position control ability and the possibility of miniaturization. Therefore,
It enables precise positioning under a strong magnetic field and precise positioning of magnetically sensitive objects. In addition, since a non-magnetic material can be used as a material constituting the stage, the weight can be significantly reduced by using Al or the like as compared with the conventional example, which enables the weight of the load to be increased.

As a specific application example, there is a coarse movement stage for a scanning tunnel microscope operating under a strong magnetic field of about 10 Tesla. In the scanning tunneling microscope, the distance between the sample and the probe needs to be kept at about several nm, and the distance between the sample and the deep needle can be adjusted by a shear type piezo element (usually 0.5 to several tens of microns). Needs a coarse movement mechanism to approach The present invention is extremely suitable as a coarse movement mechanism of a scanning tunnel microscope. When using the conventional product, it did not work under a strong magnetic field because it used a permanent magnet,
Operation is possible using the present invention. The conventional product does not operate in an extremely low temperature range of 70K or less even under a strong magnetic field. However, in the present invention, the frictional force can be optimized and a lightweight stage can be configured, so that the extremely low temperature of about 4K can be achieved. Can be used down to low temperatures.

[0011]

As described above, according to the present invention, the permanent magnet used in the prior art is not used, so that it can be used in a strong magnetic field, and the frictional force involved in driving can be easily adjusted. A possible moving stage can be provided.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, wherein (a) is a plan view, (b) is a cross-sectional front view, (c) is a side view, and (d) is a cross-sectional side view.

2 (a) is a plan view, FIG. 2 (b) is a sectional front view, FIG. 2 (c) is a side view, and FIG. 2 (d) is a sectional side view.

FIG. 3 is a sectional view showing a conventional electronic precision moving stage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Movable stage 12 Fixed stage 13 Leaf spring support stand 14 Leaf spring 15 Shear type piezo element 16 Ball made of porcelain (for example, SiC) 17 Shear type piezo element 18 Ball made of porcelain (for example, SiC)

Claims (3)

[Claims] 1. A moving stage having a fixed stage and a movable stage, wherein a shear type piezo element is used as driving means for the movable stage. A moving stage comprising: an attractive means for applying an attractive force therebetween; and a driving means using a shear type piezo element provided at all the contact portions of the fixed stage and the movable stage contacted by the attractive means. . 2. The moving stage according to claim 1, wherein a leaf spring is used as a spring of the attraction means. 3. A coil spring having a spring length adjusting screw is used as a spring of the attraction means.
The described moving stage.