CN107202803A - A kind of objective table being imaged for computer demixing scan - Google Patents

Abstract

The invention relates to a stage for computer layered scanning imaging, comprising a base 1, a Θ-axis turntable arranged on it, a Z-axis lifting displacement platform fixed on the Θ-axis turntable, and a Z-axis lifting displacement platform fixed on the Θ-axis turntable The XY-axis horizontal displacement platform on the upper surface and the adapter bracket fixed on the XY-axis horizontal displacement platform, the Θ-axis turntable can rotate in the horizontal plane, and the Φ-axis turntable is vertically fixed on the side of the adapter bracket, and the Φ-axis turntable is The hollow turntable can be rotated in the vertical plane. The hollow part of the Φ-axis turntable is also fixed with a ring holder for clamping plate-shaped samples. The sample plane is parallel to the turntable plane of the Φ-axis turntable. The hollow turntable and the ring clamp The holder is concentric; the holder includes two buckles, and the inner sides of the two buckles are provided with more than three pins for clamping the sample and corresponding to each other.

Description

An object stage for computer layered scanning imaging

technical field

The invention relates to a device for X-ray laminar imaging, in particular to an object stage for computer laminar scanning imaging.

Background technique

X-ray computerized laminography (CL) technology is a non-destructive testing method that can effectively detect the internal structure information of samples, and has a wide range of applications in industry, medical diagnosis and other fields. The object of X-ray computer layered scanning is a flat sample. During scanning, X-rays only penetrate the object at an oblique angle in the thickness direction of the sample.

The classic layered imaging method first appeared in 1916 and was first proposed by French dermatologist Andre Bocage. The early layered imaging method can image the radiation cross-section of an object at a specific depth. In 1995, the Fraunhofer Institute of Non-destructive Testing Engineering (IZFP) developed the computer layered imaging method (CL). Different from the classical layered imaging method, the computerized layered imaging method uses algorithms commonly used in the CT field to scan the target object. Reconstruction, relatively speaking, the reconstruction accuracy is high.

A typical CL system mainly includes three parts: X-ray source, detector and stage. When the object is scanned in the non-coaxial fixed tilt angle CL scanning mode, the X-ray passes through at a certain angle to the normal of the plate sample.

CL has a variety of scanning geometry modes, which are divided into linear, rocking, rotating, and spiral, and scanning time and reconstructed image quality are two key factors in scanning reconstruction. Among them, the rotary scanning can save scanning time while ensuring the quality of the reconstructed image, so CL usually adopts a rotary scanning structure. The key technology of using a rotating structure for CL scanning is how to precisely control the change of the scanning tilt angle. This type of device realizes the change of the tilt angle by rotating the sample, while the positions of the radiation source and the detector remain unchanged. This method requires a firm grip on the sample. clamping, and the position of the sample needs to be kept stable. Moreover, if the sample to be measured is fixed on a certain support for detection, the sample will be blocked by the support in at least one direction during the scanning process, thus losing part of the information. However, the existing CL system scanning mechanism generally has the defects that the detection sample is inconvenient to place and the inclination angle of the sample is inconvenient to adjust, resulting in a single scanning method for the sample and low scanning accuracy.

Contents of the invention

The object of the present invention is to provide an object stage for computer layered scanning imaging which can well hold the measured plate-shaped sample and does not block the sample. The technical scheme is as follows:

A stage for computer layered scanning imaging, comprising a base 1, a Θ-axis turntable arranged thereon, a Z-axis elevating translation platform fixed on the Θ-axis turret, and an XY platform fixed on the Z-axis elevating translation platform Axis horizontal displacement platform and an adapter bracket fixed on the XY axis horizontal displacement platform, the Θ axis turntable can rotate in the horizontal plane, and the Z axis displacement platform and the XY axis horizontal displacement platform are jointly realized in the X axis, Y axis and Z axis Axial movement, characterized in that a Φ-axis turntable is vertically fixed on the side of the adapter bracket, the Φ-axis turntable is a hollow turntable and can rotate in a vertical plane, and a clamp is fixed on the hollow part of the Φ-axis turntable The ring holder for holding plate-shaped samples, the sample plane is parallel to the turntable plane of the Φ-axis turntable, and the hollow turntable is concentric with the ring holder; the holder includes two rings, and the inner sides of the two rings are set There are more than three pins that are used to hold the sample and correspond to each other. There are small holes or grooves at the end of the pins, and plastic fixing parts are fixed on the small holes or grooves. When the holder holds the sample, each plastic The fixture is in direct contact with the sample surface.

Compared with the prior art, it has the following advantages:

(1) In terms of practicability: this device is easy to install and disassemble, and has relatively low requirements for space size, experimental conditions, and facility equipment. It can be directly modified on the basis of the original CT system, and has certain operability. It is simple and easy to realize the functional migration of CL.

(2) In terms of stability: the bottom of the base is a rubber shock-absorbing structure to reduce the small external vibrations from the optical table; the X, Y-axis translation stage and the Z-axis lifting platform are all positioned with sub-micron grating rulers to ensure that Φ When the shaft turntable is working, the angle and position deviation of the rotating shaft are small enough.

(3) In terms of controllability: the present invention uses a Θ-axis turntable to control the size of the inclination angle, which has high control precision and a large adjustable range; using a holder to fix the sample is more stable than the conventional method on the one hand, and can be adjusted by adjusting the clip. The stress in the four directions of the holder is used to keep the sample vertical.

(4) In terms of imaging quality: the present invention proposes to use a hollow turntable to change the sampling angle, so that the rays can directly pass through the sample without passing through other media (except air), which reduces the noise of the image and improves the clarity.

Description of drawings

Fig. 1 is a structural diagram of the X-ray layered scanning imaging device of the present invention.

Figure 2 is a bottom view of the mounting base.

Fig. 3 is a double-layer ring holder for clamping plate samples, (a) is the outer ring buckle, (b) is the inner ring buckle, and (c) is the holder holding the sample.

Figure 4 is a diagram of the setup with a sample holder.

detailed description

The present invention will be described below in conjunction with the accompanying drawings and embodiments.

The key technology of using a rotating structure for CL scanning is how to precisely control the change of the scanning tilt angle. Using the scanning device of the stage of the present invention, the tilt angle can be changed by rotating the sample, while the positions of the radiation source and the detector remain unchanged. Such methods require firm clamping of the sample and the need to maintain a stable position of the sample. For this reason, the present invention also improves the clamper. The improved clamper is suitable for samples with small size, regular shape, easy fixed situation.

Fig. 1 is a kind of stage that is used for computer layered scanning imaging, comprises base 1, a Θ-axis turntable 2, a Z-axis elevating translation platform 5 installed on the Θ-axis turntable, a Z-axis translation platform installed on An XY-axis horizontal displacement table 6, and a one-position shift frame 9 installed on the XY-axis horizontal displacement table, and a Φ-axis turntable 10 that rotates in a vertical plane and is arranged on the position shift frame. The Θ-axis turntable is driven to rotate in the horizontal plane by a Θ-axis drive mechanism, and the Z-axis displacement stage and the XY-axis displacement stage are respectively driven on the X-axis by an X-axis drive mechanism, a Y-axis drive mechanism and a Z-axis drive mechanism. , Y-axis and Z-axis directions, and the Φ-axis turntable is driven to rotate in a vertical plane by a Φ-axis drive mechanism. Among them, the Φ-axis turntable is a hollow turntable, and the ratio of the central aperture of the turntable to the thickness of the turntable should be greater than 2. The sample (plate) is fixed on one side of the plane of the Φ-axis turntable through transfer, and the plane of the sample is parallel to the plane of the turntable, and the turntable is concentric with the plate holder for holding the sample. When scanning and sampling, the sample rotates around the Φ axis, and the X-ray passes through the central through hole of the turntable directly through the sample at a fixed angle, and then images on the detector.

Among them, 1 is the base, 2 is the Θ-axis turntable, 3 is the Θ-axis motor, 4 is the turntable adapter plate, 5 is the Z-axis lifting platform, 6 is the XY-direction displacement table, 7 and 8 are the X-axis and Y-axis drive motors respectively , 9 is a right-angle adapter bracket, 10 is a Φ-axis hollow turntable, and 11 is a Φ-axis motor.

Fig. 2 is a bottom view of the base, the base material is alloy steel, and 12 is a rubber shock-absorbing band, which is placed in the rectangular groove below the base.

Figure 3 is a plate-shaped object holder for holding samples. The holder is a ring structure and is divided into two layers 13 and 14, both of which are made of aluminum alloy. There are four pins on the inside for holding The sample has a small hole at the end of the pin, which is used to fix the spherical plastic button 16 (PVC material). When in use, place the sample 17 of the plate to be tested between the two layers of the holder, then align the four pins of the upper and lower layers, interlock the two rings and clamp the sample. At this time, the plastic button directly contacts the surface of the sample. , and finally adjust the stress with the fastening screw 15 to make the whole structure stable.

Wherein 13 is the inner ring buckle of the holder, 14 is the outer ring buckle of the holder, 15 is a fastening screw, 16 is a PVC plastic button, which can also be called a fixing piece here, and 17 is a schematic sample.

Claims (1)

1. a kind of objective table being imaged for computer demixing scan, including base 1, the Θ axles turntable being disposed thereon, fixation Displacement platform, the XY axle horizontal position moving stage being fixed on Z axis lifting displacement platform are lifted in the Z axis on Θ axle turntables and are fixed on Switching support in XY axle horizontal position moving stage, the Θ axles turntable can be rotated in the horizontal plane, Z axis displacement platform and XY axle levels Displacement platform joint is realized in the movement of X-axis, Y-axis and Z-direction, it is characterised in that be vertically fixed with Φ axles in switching support side Turntable, the Φ axles turntable is hollow turntable and can rotated in vertical plane, is also fixed in the hollow space of Φ axle turntables There is the annular holder to grip block shape sample, sample plane is parallel with the turntable plane of Φ axle turntables, hollow turntable and ring Clevis holder is concentric；Described clamper includes being provided with the inside of two latch closures, two latch closures for clamping sample and phase Mutual corresponding more than three pins, pin end offers aperture or groove, plastic fixtures is fixed with aperture or groove, In gripper sample, each plastic fixtures directly contacts sample surfaces.