JPH0424598Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an aperture moving device for moving an aperture of an electron microscope or the like in three mutually perpendicular directions.

For example, to adjust the aperture position of an electron microscope, an aperture holder with multiple pores (apertures) with different hole diameters drilled along the longitudinal direction is adjusted on three axes so that a predetermined aperture correctly faces the beam. This is done by moving in the direction.

FIG. 1 is a structural explanatory diagram showing an example of a conventional moving device of this type, in which a shows a side cross section and b shows a cross section taken along the line A-A of a. In the figure, the shaft 1 is moved in the X direction (axial direction) by the coil spring 2.
It is inserted into the intermediate cylinder 3 in a biased state. This shaft 1 is movable only in the axial direction, and its rotation is controlled by a pin 4 implanted in the shaft 1.
and an elongated hole 5 in the axial direction formed in the intermediate cylinder 3 so that the pin 4 fits therein. One end of the intermediate tube 3 is formed into a spherical shape, and is rotatably supported by a bearing on a base 7 that is inserted into and fixed to the lens barrel wall 6. Further, a cylindrical pin guide 8 provided with a step-like guide groove is fixed in the vicinity of the elongated hole 5 of the intermediate cylinder 3 as shown in FIG. Matching pin 9 is knob 1
It is fixed at 0. Moreover, the intermediate part of the intermediate cylinder 3 is
A retainer 11 having a plane perpendicular to the Y direction and the Z direction is formed. Coil springs 12 and 13 and knobs 14 and 15, which are elements for pressing the plane of the retainer 11 to adjust the position in the Y and Z directions, are installed on the base 7 so as to sandwich the retainer 11 therebetween. An aperture holder 16 in which a plurality of holes with different diameters are bored along the longitudinal direction is fixed to one end of the shaft 1, and a fine adjustment knob 38 is screwed to the other end of the shaft 1. has been done. In addition, the fine adjustment knob 38 is attached to the pipe 3.
9 and the pipe 39 is in contact with the knob 10.

In this configuration, the shaft 1 is pushed toward the aperture holder 16 by the coil spring 2, and this force is transmitted to the knob 10 via the fine adjustment knob 38 and the pipe 39, pushing the knob 10 toward the base 7. Therefore, the position of the shaft 1 (diaphragm holder 16) in the X direction is determined by the fitting positional relationship between the pin guide 8 fixed to the intermediate cylinder 3 and the pin 9 fixed to the knob 10. On the other hand, the position of the aperture holder 16 in the Y and Z directions is
It will be determined by the screw-in amount of 15.

However, in the conventional device described above, when the knob 10 is rotated to move the shaft 1 in the axial direction, the retainer 11 is also rotated at the same time.
This has the drawback that the correct opposing relationship between the beam and the pore provided in the aperture holder 16 is impaired, and the aperture, which should be a perfect circle, becomes substantially elliptical.

The purpose of the present invention is to eliminate this drawback, and includes a shaft with an aperture holder fixed to one end, two spherical parts protruding from the outer periphery, and an internal structure that allows the shaft to move only approximately in the axial direction. A movably inserted intermediate cylinder, a base that supports one spherical part of the intermediate cylinder with the cylindrical part, a bellows fixed between the cylindrical part of the base and the shaft, and the other of the intermediate cylinder. a first slider having an inner cylindrical surface in line contact with the spherical surface of the spherical portion; the first slider is movably guided in one direction orthogonal to the axial direction of the shaft; a second slider movably guided in a direction perpendicular to the moving direction of the first slider; a first feeding means for displacing the first slider; and a second slider for displacing the second slider. a feeding means, a third feeding means for displacing the shaft in the axial direction using a screw, and a third feeding means formed on either the other spherical part of the intermediate cylinder or the inner cylinder surface of the first slider. a pin groove extending in the direction of movement of either the first slider or the second slider, and a spherical portion of the other intermediate cylinder and an inner cylinder surface of the first slider. The present invention is characterized by comprising a pin provided on the other side and engaged with the pin groove.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a configuration explanatory diagram showing an embodiment of the present invention, in which a is a plan sectional view of the main part, b is a side sectional view,
c is a BB sectional view of b. In Figure 3,
The shaft 17 is inserted into the intermediate cylinder 18 so as to be movable in the axial direction (X direction), and its rotation is restricted. That is, the pin 19 implanted in the shaft 17
It is fitted into an elongated hole 20 bored in the axial direction of the intermediate cylinder 18 . Further, two spherical portions 21 and 22 are formed on the outer periphery of the intermediate cylinder 18. One spherical portion 21 of the intermediate cylinder 18 is supported by the cylindrical portion of the base 23. A bellows 24 is fixed to the end of the cylindrical portion of the base 23, and one end of the shaft 17 is inserted and fixed to the movable end of the bellows 24. Further, at the end of the shaft 17 passing through the movable end of the bellows 24, there is a diaphragm holder 16 similar to that shown in FIG.
is installed. A threaded portion 25 is formed in the axial direction on the other end of the shaft 17, and a nut 2 is inserted therein.
6 are screwed together. The other spherical part 2 of the intermediate cylinder 18
A pin 27 is protruded from the outer periphery of the slider 2, and when the pin 27 is fitted into the pin groove 28, the spherical surface of the spherical portion 22 is in line contact with the inner cylindrical surface formed on the slider 29. Further, the slider 29 is fitted into the slider 30 by a dovetail groove, and is movable relative to the slider 30 only in the Y direction. Similarly, the slider 30 is fitted into the base 23 by a dovetail groove,
With respect to the base 23, it is movable only in the Z direction. Further, a cap 33 is attached to the base 23, and coil springs 31 and 32 for moving the slider 29 in the Y direction are disposed on the cap 33. On the other hand, a coil spring 34 and a knob 35 for moving the slider 30 in the Z direction
is arranged directly on the base 23. A bush 36 is inserted between one end of the coil spring 31 and the slider 29, and a push screw 37 for adjusting the pressing force is provided at the other end of the coil spring 34.

In this configuration, the shaft 17 is always pressed toward the aperture holder 16 due to the pressure difference on both sides of the bellows 24 (the outside of the bellows is in a vacuum), and by rotating the nut 26, the shaft 17 (aperture The holder 16) can be moved in the X direction, and by rotating the knob 32, the aperture holder 1 can be moved through the spherical part 22 of the intermediate cylinder 18.
6 can be moved in the Y direction, and by rotating the knob 35, the aperture holder 16 can be moved in the Z direction via the spherical portion 22 of the intermediate cylinder 18. Here, focusing on the operation when moving the shaft 17 in the axial direction, the pin 27 is fitted into the pin groove 28, and the spherical portion 22 of the intermediate cylinder 18 whose rotation is restricted relative to the first slider 29 is as follows. It is supported by sliders 29 and 30 that can only move in two directions orthogonal to each other and cannot rotate, and their rotation is also restricted by the bellows 24, so that the shaft 17 cannot be moved as in the conventional structure. The intermediate cylinder does not rotate during movement in the X direction, resulting in stable operation. Moreover, since the movements in the Y and Z directions can be performed completely independently, there is no interference and the adjustment accuracy is improved.
Furthermore, the spherical surface of the other spherical portion 22 is connected to the slider 29
Since the spherical portion 22 is in line contact with the inner cylindrical surface of the slider 29, the spherical surface of the spherical portion 22 is always reliably supported by the inner cylindrical surface of the slider 29 even when adjustments are made in the Y and Z directions.
Therefore, the two spherical portions 21 and 22 of the intermediate cylinder 18 are always supported on the base 23 side and are less susceptible to vibrations.

Note that the mechanism for moving the shaft 17 in the axial direction is not limited to the one shown in FIG. 3, and the mechanism shown in FIG. 1 may be used, or the moving mechanism may be configured to be rotationally driven by a motor. . In the case of motor drive, highly accurate position control can be performed by a computer or the like by using a pulse motor. Furthermore, a potentiometer may be used in combination for motor-driven position control. Moreover, in the above embodiment,
The pin 27 was provided on the other spherical portion 22 and the pin groove 28 was provided on the first slider 29, but conversely, a pin groove was provided on the other spherical portion and a pin that fit into the pin groove was provided on the first slider. You can also do this.

Further, in the above embodiment, an example of an aperture moving device for an electron microscope has been described, but the present invention can also be applied to other similar devices.

As explained above, according to the present invention, when the shaft (aperture holder) is moved in the X direction, no permanent rotational displacement is caused in the aperture holder. Furthermore, the aperture holder can be reliably moved in two directions, Y and Z. Therefore, it is suitable as an aperture moving device for various devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional device, FIG. 2 is a block diagram of a portion thereof, and FIG. 3 is a block diagram showing an embodiment of the present invention. 16...Aperture holder, 17...Shaft, 18
...Intermediate tube, 19,27...Pin, 20...Elongated hole, 21,22...Spherical part, 23...Base, 2
4... Bellows, 25... Threaded portion, 26... Nut, 28... Pin groove, 29, 30... Slider,
31, 34... Coil spring, 32, 35... Knob, 33... Cap, 36... Bush.

Claims (1)

[Claims for Utility Model Registration] A shaft with an aperture holder fixed to one end, an intermediate cylinder with two spherical parts protruding from its outer periphery, and an intermediate cylinder into which the shaft is inserted so as to be movable only approximately in the axial direction. , a base supporting one spherical part of the intermediate cylinder with the cylindrical part; a bellows fixed between the cylindrical part of the base and the shaft; and a bellows in line contact with the spherical surface of the other spherical part of the intermediate cylinder. a first slider formed with an inner cylindrical surface; the first slider is movably guided in one direction perpendicular to the axial direction of the shaft, and the base guides the first slider in the direction of movement of the first slider; a second slider movably guided in orthogonal directions; a first feeding means for displacing the first slider; a second feeding means for displacing the second slider; a third feeding means for displacing in the axial direction using the second spherical portion of the intermediate cylinder and an inner cylinder surface of the first slider; a pin groove extending in the moving direction of one of the second sliders; a pin groove provided in the other spherical part of the intermediate cylinder and the other of the inner cylinder surface of the first slider; An aperture moving device comprising: a pin that engages with;