JP3471477B2 - Variable slit device for X-ray equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable slit device used in an X-ray device.

[0002]

2. Description of the Related Art X-ray diffractometer, X-ray reflectance measuring device, X-ray
In a linear stress measuring device, an X-ray small angle scattering device, and various other X-ray devices, a sample to be measured is irradiated with X-rays,
The measurement is performed by detecting X-rays that are diffracted, reflected, scattered, etc. in the sample by an X-ray counter or the like. In such an X-ray apparatus, in order to regulate the beam width of X-rays that are incident on the sample or diffracted by the sample, slits are arranged at appropriate places on the optical path of the X-ray beam, usually at a plurality of places. There is also known a slit device in which the slit width can be changed, that is, a variable slit device, in order to change the width of the X-ray beam to a desired value.

For example, looking at an X-ray diffractometer that is widely used in general, as shown in FIG. 5, the divergence angle of the X-ray R emitted from the X-ray source F and diverging is determined by the pair of slit members 5.
The sample S is irradiated with the regulated X-ray beam. The slit member 51 used here is often called a divergence regulation slit or the like because its main purpose is to limit divergence of X-rays. By the way, in a general X-ray diffractometer, measurement is often performed while rotating the sample S at a predetermined angular velocity θ. And in that case,
In order to maintain the X-ray irradiation area A of the sample constant even when the angle θ changes, it is desirable to change the slit width W _S of the slit member 51 according to the rotation angle θ.

As a mechanism for changing the slit width in this way, conventionally, as shown in FIG. 6, four links 5 are used.
There is a so-called pantograph mechanism including 2a to 52d. In this mechanism, the pair of links 52b
And 52d are rotatably and immovably supported by a rotary shaft 53, and a pair of slit members 51 are fixed to the tips of another pair of links 52a and 52c. By driving one of the links, for example, the link 52c, to move straight by the stepping motor 53 or the like, the links 52a and
2c is moved parallel to the opposite directions, thereby to open and close the slit width W _S of the slit member 51.

Further, as another mechanism for changing the slit width, conventionally, as shown in FIG. 7, a guide rod 5 is used.
The pair of slit members 51 guided by 4 are meshed with a screw shaft 55 having a reverse screw spiral direction, that is, a so-called reverse screw is cut, and the screw shaft 55 is rotated by a handle 56 or the like to form a slit width W _S. A mechanism that opens and closes is known.

[0006]

However, in each of the conventional variable slit devices described above, the entire mechanism becomes large, which hinders downsizing of the X-ray device using the mechanism, backlash and other problems. There are problems that the accuracy of the slit width control becomes poor due to the influence of the error, and that the cost becomes high to improve the accuracy.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a variable slit device which is capable of controlling the slit width with high accuracy and is small in size and inexpensive. .

[0008]

In order to achieve the above object, a variable slit device for an X-ray device according to the present invention is provided with an X-ray
You can regulate the beam to a specified width and adjust the regulation width
In a variable slit device for an X-ray device, a pair of slit members forming a slit width for passing the X-ray beam, a cam follower member integrated with each slit member, and arranged between the cam follower members. Before
Parallel to the cam rotates, the cam follower member possess an elastic pressing member for pressing elastically on the cam, the cam and the axis of rotation about a rotation axis extending in a direction perpendicular to the opening and closing direction of the serial slit member Moth extending in the direction of
And the pair of cam follower members have
It is characterized by making line contact with the guide surface of .

The above-mentioned cam has an arbitrary shape as long as it is arranged between the cam follower members. However, it is desirable that the cam has a certain length that can act as a guide surface in the rotation axis direction. With this configuration, the pair of cam follower members come into line contact with the guide surfaces thereof, and therefore the guide surfaces can reliably prevent the slit member from tilting. As a result, it is not necessary to provide any special guide means other than the cam in order to prevent the inclination of the slit member.

Further, as a concrete shape of the cam, an elliptic cam centered on the rotation axis of the cam, or
It is also possible to form the cam by two columnar pins that are adjacent to each other with the axis of rotation of the cam as a boundary. When using two cylindrical pins, the cam is formed by simply preparing two ready-made cylindrical pins and arranging them.
The structure of the variable slit device is extremely simple and the manufacturing cost is extremely low. Also, since the linearity of the outer peripheral side surface of the cylindrical pin can be finished with extremely high accuracy,
If the outer peripheral side surface is used as a guide surface for the cam follower member, it is possible to more reliably prevent the slit member from tilting when the cam follower member, and hence the slit member, is opened and closed. When two cylindrical pins are used, the cam surface that contacts the cam follower member is an arc surface, so when the cam rotates at the angular velocity θ,
The cam follower member, and hence the slit member, can be opened and closed at an opening and closing speed of sin θ. This is X
X incident on the sample rotating and moving at an angular velocity θ with respect to the radiation source
It is particularly advantageous with regard to keeping the illuminated area of the line constant.

The variable slit device according to the present invention can be installed at any position of various X-ray devices. However, it is considered that the most effective function is used as a slit for limiting the divergence of incident X-rays emitted from the X-ray source and incident on the sample, that is, a so-called divergence regulation slit. Further, when an X-ray device of a type having a θ rotation drive system for rotating the sample to be measured by θ is adopted, the cam in the variable slit device and the θ rotation drive system are driven by the power transmission means. It is desirable that the slit members in the variable slit device are connected and opened / closed by utilizing the driving force of the θ rotation driving system. As such a power transmission means, a gear train, a belt transmission system, a chain transmission system, or any other power transmission device can be applied, but a drive system including a worm and a worm wheel is used as a θ rotation drive system on the X-ray device side. When adopting, it is convenient to configure the power transmission device using a gear train. Further, when it is not possible to connect to the θ rotation drive system for structural reasons, it is possible to prepare a motor drive system in the variable slit device and rotate the motor synchronously with the angular velocity θ.

[0012]

In the variable slit device of the present invention, the rotation of the cam causes the pair of cam follower members to open and close, and as a result,
A pair of slit members that are integral with the cam follower member are opened and closed. And by opening and closing movement of this slit member,
The slit width for passing the X-ray beam is adjusted. Since the cam is arranged between the pair of cam follower members, the mechanism around the slit member is remarkably small and simple as compared with the case where the pantograph mechanism or the screw shaft mechanism is used. Also, the manufacturing cost is reduced.

[0013]

FIG. 3 schematically shows an example of an X-ray device to which the variable slit device of the present invention can be applied, particularly an X-ray diffractometer equipped with a .theta.-2.theta. Scanning goniometer. This X
The line diffraction device includes, for example, an X-ray source F that emits line-focused X-rays, a pair of slit members 1 that function as divergence regulation slits, a sample S to be measured, a light-receiving slit 2, and an X-ray counter 3 And have. The X-ray source F, the rotation axis P of the sample S, and the three points of the light receiving slit 2 are located on the concentrated circle E.

As shown in FIG. 1, the sample S is mounted on a sample table 4 and a worm wheel 5 is fixed to the sample table 4. This worm wheel 5 is a worm 6
The worm 6 is rotated by being driven by a rotary drive source, for example, a stepping motor 7. Due to the action of the worm rotation drive system, the sample S rotates continuously or intermittently about the rotation axis P at a predetermined angular velocity,
So-called θ rotation. In FIG. 3, the light-receiving slit 2 and the X-ray counter 3 are configured as one unit and can be moved by 2θ rotation about the rotation axis P of the sample. This 2θ rotation is brought about by the action of a rotation drive system different from the θ rotation drive system of the sample S, and is a rotation that moves in the same direction as the θ rotation at an angular velocity 2θ that is twice the angular velocity θ of the sample S. Is.

In FIG. 3, while the sample S rotates by θ and the X-ray counter 3 rotates by 2θ at the same time, the divergence angle of the X-ray beam emitted from the X-ray source F and diverged is limited by the divergence regulation slit 1. The sample S is incident in this state. When the X-ray diffraction conditions are satisfied between the incident X-rays and the crystal lattice plane of the sample S, X-ray diffraction occurs, and the diffracted X-rays are focused on the light receiving slit 2 to pass through the slit 2. After passing, it is detected by the X-ray counter 3. Thus, the diffraction angle 2
The relationship between θ and the diffracted X-ray intensity at the diffraction angle is obtained as a so-called X-ray diffraction pattern, and the characteristics of the sample S, such as the material components contained in the sample S, are determined based on the X-ray diffraction pattern. To be done.

The internal structure of the portion B on the X-ray incidence side in FIG. 3 is shown in FIG. 1, and the variable slit device 8 is included in this portion. The variable slit device 8 includes a pair of slit members 1 and a pair of cubic cam follower members 9 that integrally support the slit members 1.
And two cylindrical pins 10a and 10b arranged between the cam follower members 9. As shown in FIG. 2, these cylindrical pins 10a and 10b are fixed to the upper end of the rotary shaft 13 integrated with the gear 12 by adhesion, screwing, or the like. Further, these cylindrical pins are adjacent to each other with the rotation center axis line Q of the rotation shaft 13 as a boundary, and their outer peripheral side faces G are precisely finished in a linear shape, and are formed at least longer than the height of the cam follower member 9. And serves as a guide surface for the cam follower member 9. The gear 12 meshes with a worm wheel 5 that constitutes a θ rotation drive system for rotating the sample S by θ.

In FIG. 1, the left and right sides of the cam follower member 9 are guided by the guide members 14 and 15, so that the cam follower member 9 moves parallel to the X-ray optical path L toward or away from the X-ray optical path L as shown by an arrow H. .
A compression spring 16 as an elastic pressing member is provided on the back surface of the cam follower member 9 with respect to the X-ray optical path L, and the spring force of these springs causes the cam follower member 9 to apply pressure to the outer peripheral side surface G of the cylindrical pins 10a and 10b. Are in contact with.

Since the variable slit device 8 according to the present invention is constructed as described above, the sample S is used for the X-ray diffraction measurement.
Is rotated by the rotation of the worm wheel 5,
The θ rotation is transmitted to the rotary shaft 13 by the gear 12, and the rotary shaft 13 rotates at the angular velocity θ. When the rotary shaft 13 rotates, the cylindrical pins 10a and 10b rotate about the rotation center axis line Q.
, And the cam follower members 9 contacting their outer peripheral side surfaces G move in the direction of arrow H in accordance with the rotation of the cylindrical pins. Then, in response to this, the slit member 1 opens and closes with respect to the X-ray optical path L, and the slit width W _S changes.

The slit width W _{S at} this time is W _S =, where D / 2 is the diameter of each cylindrical pin 10a, 10b, that is, D is the cam diameter when these cylindrical pins are considered as one cam. It is represented by D · sin θ. That is, when the sample S rotates by θ,
The slit width of the slit member 1 is si depending on the θ rotation.
It changes at the rate of nθ. In this way, by changing the slit width of the slit member 1 that acts as a divergence regulating slit at a rate of sin θ according to the θ rotation of the sample S, the irradiation area of the X-ray that irradiates the sample S through the slit width. A can be maintained at a substantially constant size regardless of the rotation angle θ of the sample S. As a result, highly reliable diffracted X-ray information can be obtained from the sample S.

Further, since the outer peripheral side surfaces G of the cylindrical pins 10a and 10b are precisely formed in a linear shape and the surfaces are also used as guide surfaces for the cam follower member 9, the slit member 1 is opened and closed. As shown by arrow K in FIG. In a normal opening / closing mechanism, it is necessary to install a dedicated guide mechanism in order to prevent such tilt movement, but in the present embodiment, such a special guide mechanism is unnecessary.

The present invention has been described above with reference to the preferred embodiments, but the present invention is not limited to the embodiments and can be variously modified within the technical scope described in the claims.

For example, in the embodiment shown in FIG. 1, the cam 11 is composed of two cylindrical pins 10a and 10b, but in addition to that, as shown in FIG. 4, it is provided with semicircular cam surfaces 20a and 20b. An elliptical cam 21 can be used. Further, in the embodiment shown in FIG. 2, the outer peripheral side surfaces G of the cylindrical pins 10a and 10b acting as cams are set to be long in the direction of the rotation axis Q, and the side surfaces G are inclinedly moved by the cam follower member 9, and hence the slit member 1 is inclined. Although it also serves as a guide surface for preventing movement, the cam does not necessarily have to serve as such a guide surface. Further, the variable slit device of the present invention is not limited to the divergence regulation slit arranged between the X-ray source and the sample, but can be used as an appropriate slit arranged at other places. Further, the variable slit device of the present invention can be applied to any X-ray device other than the X-ray diffractometer shown in FIG. 3, that is, the X-ray diffractometer including the θ-2θ scanning type goniometer.

According to the variable slit device for the X-ray apparatus of the present invention, the cam follower member integrated with the slit member is directly opened / closed by the rotation of the cam.
High-precision slit width control is possible without being affected by errors such as backlash. Moreover, it is possible to obtain a variable slit device that is smaller and less expensive than a conventional opening / closing drive mechanism that uses a pantograph mechanism, a screw shaft mechanism, or the like. Also,
According to the variable slit device for the X-ray device of the present invention,
The guide surface extends parallel to the axis of rotation.
You can open and close the slit member without tilting it.
Moreover, it is not necessary to provide a dedicated guide mechanism.

[0024]

According to the variable slit device for the X-ray apparatus of the present invention having the structure using the cylindrical pin, the cam can be formed using the ready-made cylindrical pin, so that the manufacturing cost can be further reduced. Further, since the outer peripheral side surface of the cylindrical pin can be accurately finished in a linear shape, when the side surface is also used as a guide surface for the cam follower member, the cam follower member, and hence the slit member, can be moved in parallel with high accuracy. You can

The cam and the θ rotation system are connected by a power transmission means.
According to the variable slit device for an X-ray device of the present invention having the structure of connection, the divergence regulation slit arranged between the X-ray source and the sample in the X-ray device can be configured as a variable slit with a simple configuration. Further, the irradiation area of the X-ray incident on the sample on the sample surface can always be maintained accurately and constantly regardless of the change in the θ rotation angle of the sample.

[0027]

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a variable slit device for an X-ray device according to the present invention.

FIG. 2 is a side sectional view taken along the arrow II in FIG.

FIG. 3 is a plan view schematically showing an example of an X-ray device to which the variable slit of the present invention is applicable, particularly an X-ray diffraction device including a θ-2θ scanning type goniometer.

FIG. 4 is a plan view showing another embodiment of the variable slit device for an X-ray device according to the present invention.

FIG. 5 is a plan view schematically showing the relationship between a divergence regulation slit and a sample in a general X-ray diffractometer.

FIG. 6 is a front view showing an example of a conventional slit opening / closing mechanism.

FIG. 7 is a front view showing another example of the conventional slit opening / closing mechanism.

[Explanation of symbols]

1 slit member 2 Light receiving slit 3 X-ray counter 4 sample table 5 worm wheel (slit side gear) 6 worms 8 variable slit device 9 Cam follower member 10a, 10b cylindrical pin 11 cams 12 gears (power transmission means) 13 rotation axis 16 Compression spring (elastic pressing member) 20a, 20b circular arc surface 21 Elliptical cam A X-ray irradiation area on the sample D cam diameter E Goniometer concentrated circle F X-ray source G cam outer peripheral side surface (guide surface) L X-ray optical axis Center of rotation of P sample Center of rotation of Q-cam R X-ray S sample

Claims (5)

(57) [Claims] 1. A variable slit apparatus for an adjustable X-ray apparatus the regulation width while regulating the X-ray beam in a predetermined width, a pair of slit members forming the slit width for passing the X-ray beam , each slit member and integral with the cam follower member, a cam which rotates about a rotation axis extending in a direction perpendicular to the opening and closing direction of the scan <br/> slit member is disposed therebetween of the cam follower member, and an elastic pressing member for pressing said cam follower member elastically to said cam, said cam guide surface extending in a direction parallel to the axis of rotation
And the pair of cam follower members are
A variable slit device for an X-ray device, which is in line contact with the scanning surface. 2. A variable slit apparatus for X-ray apparatus according to claim 1, wherein the cam is X-ray apparatus for variable slit apparatus, characterized in that the elliptical cam around the axis of rotation. 3. A variable slit apparatus for X-ray apparatus according to claim 1, wherein the cam axis of rotation X-ray device for variable slit apparatus characterized by being constituted by two adjacent cylindrical pin as boundary . 4. Any one of claims 1 to 3
The variable slit apparatus for X-ray apparatus according to One, X-ray apparatus has a sample θ rotating system that rotates θ to be measured, the cam and its θ rotation system in the power transmission means
Therefore, the variable screw is connected by the driving force of the θ rotation system.
A variable slit device for an X-ray device , which is capable of opening and closing a door. 5. A variable slit apparatus for X-ray apparatus according to claim 4, wherein said power transmission means includes a sample side gear which rotates the sample integral to said cam and integral with meshes with the sample side gear We possess a slit-side gear which is rotated by the driving force of the θ rotation system, the variable slit opening
Variable slit apparatus for X-ray apparatus, characterized in that the closing.