KR100570500B1 - A x-ray detecter - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray detector, wherein a scintillator film is deposited on one surface of a subject, and image amplification is performed by converting visible light converted by the scintillator into photons and then converting the light into an amplified visible light by accelerated collision with a fluorescent surface. Tube, an autofocus magnification converting camera unit for detecting visible light amplified by the image amplification tube and converting the image into a predetermined distance from the image amplifying tube, and amplifying the visible light amplified by the image amplification tube by a predetermined magnification. And a depth compensator for compensating a depth of the auto focus magnification converting camera unit.

X-ray, X-ray, Detector, Focus, CCD

Description

X-ray Detecter

1 is a cross-sectional view showing the structure of an X-ray detector according to the present invention.

FIG. 2 is a diagram illustrating a detailed structure of the image amplifying tube of FIG. 1.

3 is a diagram illustrating a detailed structure of the depth compensation unit of FIG. 1.

4 is a diagram illustrating detailed specifications of the first lens.

5 is a diagram illustrating detailed specifications of a second lens.

6 is a diagram illustrating detailed specifications of a third lens.

<Description of main drawing code>

10 carbon fiber layer 20 scintillator film

30: image amplification tube 40: space part

50: depth compensation unit 60: auto focus magnification conversion camera unit

70 housing

The present invention relates to an X-ray detector, and more particularly, to enable precise inspection using low-energy X-rays to be suitable for inspection of medical-related parts, and to enable real-time autofocus magnification conversion using a depth compensation lens. It relates to an X-ray detector.

The X-ray detector converts the X-rays into light by a scintillator coated on the input surface, which is then converted back into photons, amplified by an electron gun inside, and then converted into visible light in the process of colliding with the fluorescent material in the output window. The CCD camera converts this into an image.

Conventional X-ray detectors use high-density, high-energy X-rays because they are difficult to inspect with low-energy X-rays. Therefore, when the conventional x-ray equipment is used in low-density products such as medical-related parts, since the x-rays are transmitted through most of the products without absorption or reflection, there is a problem that precise inspection is impossible.

In addition, conventionally, the optical fiber glass coated with the scintillator is attached to the front surface of the image amplification tube through an adhesive, which causes a problem in that the light transmission efficiency is lowered by the adhesive.

In addition, when using an autofocus magnification camera to implement a real-time autofocus magnification conversion function, the operating distance between the camera and the video amplification tube should be fixed to about 35mm to satisfy an angle of view of 25 mm in diameter of the input window of the image amplification tube. In this case, in order to focus at a predetermined magnification, the focal length of the camera itself may exceed 35 mm, causing a problem of blurring or cropping of an image.

Accordingly, there is a growing demand for an X-ray detector that can overcome the problems of the conventional X-ray detector and use a low-density energy to make precise measurements and obtain accurate images when providing an auto focus magnification conversion function.

The present invention has been made to solve the above problems, it is an object of the present invention to provide an X-ray detector to enable a precise inspection using a low-energy X-ray to be suitable for the inspection of medical-related components.

Another object of the present invention is to provide an X-ray detector for enabling real-time autofocus magnification conversion using a depth compensation lens.

Still another object of the present invention is to provide an X-ray detector capable of minimizing light loss by depositing and coating a scintillator directly onto an image amplifying tube.

According to an aspect of the present invention for achieving the above object, a scintillator film is deposited on one surface of the subject side, amplified by converting visible light converted by the scintillator into photoelectrons and then accelerated collision to the fluorescent surface An image amplification tube converting into visible light, an autofocus magnification converting camera unit detecting a visible light amplified by the image amplifying tube and converting it into an image, and positioned to be spaced apart from the image amplifying tube by a predetermined distance, and amplified by the image amplifying tube An X-ray detector is provided, comprising a depth compensator for compensating a depth of the auto focus magnification converting camera unit by amplifying a predetermined amount of visible light.

The scintillator film is preferably formed by depositing and coating a scintillator at a thickness of 1 to 3 microns on an input window of the image amplifier in a vacuum state of 10 ⁻³ to 10 ⁻⁴ atm.

The depth compensator may include a first negative lens-type lens having a convex surface on an image side, a second concave-type lens located at a rear end of the first lens, and a concave-type second lens concave on both sides, and a rear surface of the second lens. It is configured to include a convex convex-type third lens, and is preferably designed to have a 10 times light magnification, a focal length of 2.4 to 3.0 mm, a beam angle of 40 to 60 °, and a resolution of 25 to 35 Lp / mm. Do.
Here, the first lens has a center thickness (CT) = 5 to 15 mm, an edge thickness (ET) = 4 to 8 mm, and an effective focal length (EFL) = 5 to 15 mm. mm, Back Focal Length (BFL) = 8 to 10 mm, Lens diameter = 29 to 33 mm, Object side lens curvature = 90 to 94, Image lens curvature = 550 to 570, The second lens is between center Thickness = 3 to 7 mm, Edge to Edge Thickness = 6 to 10 mm, Effective Focal Length = 5 to 15 mm, Rear Focal Length = 9 to 13 mm, Lens Diameter = 29 to 33 mm, Object Side Lens Curvature = 550 to 650, Image Side Lens curvature = 220 to 260, the third lens has an inter-center thickness = 5 to 8 mm, an edge-to-edge thickness = 1 to 3 mm, effective focal length = 40 to 60 mm, rear focal length = 45 to 50 mm, lens diameter It is more preferable that it is = 29-33 mm.

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Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a cross-sectional view showing the structure of an X-ray detector according to the present invention.

As shown in FIG. 1, the X-ray detector according to the present invention includes a carbon fiber layer 10, a scintillator film 20, an image amplifying tube 30, a depth compensator 50, and an autofocus magnification conversion camera unit 60. ) Is firmly fixed in the housing 70.

The scintillator film 20 is used to convert X-rays into visible light, and the type and thickness of the scintillator is important in order to obtain a high-resolution X-ray image with low energy X-rays.

In the present embodiment, the scintillator film 20 uses CsI (Cesium Iodine) having high light conversion efficiency on the input window 36 of the image amplification tube 30 in a vacuum of 10 ⁻³ to 10 ⁻⁴ atm. It is formed by direct deposition coating to a thickness of ˜3 micron.

When the thickness of the scintillator is less than 1 micron, the resolution is increased but the brightness is lowered. If the thickness of the scintillator is more than 3 microns, the brightness is improved and the resolution is decreased. The optimum condition is obtained experimentally when the thickness is about 2 micron.

The image amplification tube 30 is for amplifying the visible light converted by the scintillator film 20 after converting it into photoelectrons, which will be described in detail with reference to FIG. 2.

The depth compensator 50 is positioned to be spaced apart from the image amplifying tube 30 by a predetermined distance, and compensates the depth of the autofocus magnification converting camera unit 60 by amplifying a predetermined magnification of the visible light amplified by the image amplifying tube 30. This will be described in detail with reference to FIG. 3.

The autofocus magnification conversion camera unit 60 detects the visible light amplified by the image amplification tube 30 and converts the image into an image. An autofocus zoom camera is used to automatically adjust the focus when zooming in or out.

FIG. 2 is a diagram illustrating a detailed structure of the image amplifying tube 30 of FIG. 1.

As shown in FIG. 2, light passing through the input window 36 is converted into photoelectrons by the photocathode 31, and when the high voltage is applied to the micro channel plate 33 positioned at the center, the converted photoelectrons are thousands of times. The amplified photoelectrons collide with the fluorescent surface 35 applied to the output window 37 and are converted into visible light and output again.

3 is a diagram illustrating a detailed structure of the depth compensation unit 50 of FIG. 1.

As shown in FIG. 3, the depth compensation unit 50 is located at the rear end of the first lens 51 and the first lens 51 of the negative meniscus type having a convex surface on the image side, and both surfaces thereof are located at the rear end of the first lens 51. A convex-shaped second lens 52 and a convex-type third lens 53 which are located at the rear end of the second lens 52 and convex on both sides thereof are firmly fixed to the barrel 56.

Spacing rings 54 and 55 are provided between the first lens 51 and the second lens 52 and between the second lens 52 and the third lens 53 to maintain the gap between the lenses. A front end of the first lens 51 is provided with a screw ring 57 for fixedly coupling the first lens 51.

Above the depth compensation section 50, a screw 58 is provided for fixing the depth compensation section 50 to the auto focus magnification conversion camera section 60.

In the present invention, the depth compensator 50 performs functions such as depth compensation, aberration correction, and chromatic aberration removal using different types of composite lenses.

Since the diameter of the output window of the image amplifying tube 30 is 25 mm, when the distance between the image amplifying tube 30 and the auto focus magnification conversion camera unit 60 is closer than 35 mm, a part of the object is not visible, thereby operating a distance of at least 35 mm. If the distance between the image amplification tube 30 and the autofocus magnification conversion camera unit 60 is maintained at 35 mm or more, the focal length of the camera unit 60 itself exceeds 35 mm, and thus the autofocus magnification conversion camera unit The zoom in and zoom out operations of 60 are greatly limited.

Therefore, the depth compensation unit 50 zooms in and out of the autofocus magnification converting camera unit 60 while the operating distance between the autofocus magnification converting camera unit 60 and the image amplifying tube 30 is fixed to 35 mm. The first to third lenses 51 to 53 are designed to be not limited.

To this end, the depth compensator 50 is designed to have a 10-fold magnification, a focal length of 2.4 to 3.0 mm, a beam angle of 40 to 60 °, and a resolution of 25 to 35 Lp / mm.

4 to 6 are drawings illustrating detailed structures and standards of the first to third lenses 51 to 53.

In order to satisfy the above conditions, the first lens 51 has a center thickness (CT) = 5 to 15 mm, an edge thickness (ET) = 4 to 8 mm, and an effective focal length (EFL: Effective Focal). Length) = 5 to 15 mm, Back Focal Length (BFL) = 8 to 10 mm, Lens diameter = 29 to 33 mm, Object-side lens curvature (R ₁ ) = 90 to 94, Image lens curvature (R ₂ ) = 550 to 570, the second lens 52 has CT = 3 to 7 mm, ET = 6 to 10 mm, EFL = 5 to 15 mm, BFL = 9 to 13 mm, diameter = 29 to 33 mm , Object-side lens curvature = 550 ~ 650, image-side lens curvature = 220 ~ 260, the third lens 53 is CT = 5 ~ 8 mm, ET = 1 ~ 3 mm, EFL = 40 ~ 60 mm, BFL = 45 Designed to be ~ 50 mm, diameter = 29 ~ 33mm, when using the depth compensation unit 50 manufactured in accordance with the design did not occur the phenomenon that the image is blurred or part of the image is cut off at the time of auto focus magnification conversion.

According to the present invention as described above, there is an effect that it is possible to provide an X-ray detector to enable a precise inspection using a low-energy X-ray to be suitable for the inspection of medical-related components.

In addition, there is an effect to enable real-time autofocus magnification conversion using a depth compensation lens.

In addition, by directly depositing the scintillator on the image amplification tube, there is an effect that can minimize the light loss.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (5)

An image amplifier tube coated with a scintillator film on one surface of a subject, and converting the visible light converted by the scintillator into photoelectrons and then accelerating collision with the fluorescent surface to convert the amplified visible light into an amplified visible light; An autofocus magnification converting camera unit detecting the visible light amplified by the image amplifying tube and converting the visible light into an image; And And a depth compensator positioned to be spaced apart from the image amplification tube by a predetermined distance and compensating a depth of the auto focus magnification converting camera unit by amplifying a predetermined magnification of visible light amplified by the image amplifying tube. The method of claim 1, The scintillator film is formed by depositing and coating a scintillator at a thickness of 1 to 3 microns on an input window of the image amplifying tube in a vacuum state of 10 ⁻³ to 10 ⁻⁴ atm. The method of claim 1, The depth compensation unit A first negative lens type lens having a convex surface on the image side; A concave-type second lens positioned at a rear end of the first lens and concave on both surfaces thereof; And And a convex-type third lens positioned at a rear end of the second lens and convex on both sides thereof. The method of claim 3, wherein And the depth compensator is designed to have a 10x magnification, a focal length of 2.4 to 3.0 mm, a beam angle of 40 to 60 °, and a resolution of 25 to 35 Lp / mm. The method of claim 4, wherein The first lens has a center thickness (CT) = 5 to 15 mm, an edge thickness (ET) = 4 to 8 mm, an effective focal length (EFL) = 5 to 15 mm, Back Focal Length (BFL) = 8 to 10 mm, lens diameter = 29 to 33 mm, object side lens curvature = 90 to 94, image lens curvature = 550 to 570, The second lens has an inter-center thickness = 3 to 7 mm, an edge-to-edge thickness = 6 to 10 mm, an effective focal length = 5 to 15 mm, a rear focal length = 9 to 13 mm, a lens diameter = 29 to 33 mm, and an object-side lens. Curvature = 550 ~ 650, image lens curvature = 220 ~ 260, The third lens has an inter-center thickness of 5 to 8 mm, an inter-edge thickness of 1 to 3 mm, an effective focal length of 40 to 60 mm, a rear focal length of 45 to 50 mm, and a lens diameter of 29 to 33 mm. X-ray detector.

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