JPS5960300A - Radiation image reader - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (A) Technical field of the invention
03) Background of the technology Regarding the radiation image reading device housing designed to emit C 3) Background of the technology X-rays can be used to investigate the internal structure and defects of ordinary objects, as well as to investigate the internal structure of the human body. Although this method is practiced in the field, it has been desired to reduce the amount of X-rays irradiated to the subject because as the amount of X-rays irradiated increases, the adverse effects on the operator and the human body become greater.

C) Prior art and problems When obtaining an X-ray image, conventionally the finger was placed behind the subject. An X-ray image was projected and stored on the original plate, and then electromagnetic waves such as laser light were irradiated and scanned to read the image of the emitted object.

Conventionally, fluorescent plates have been made by coating an opaque substrate with powdered phosphor dispersed in a binder. Therefore, the fluorescent light emitted at that time must be detected from the side scanning the electromagnetic waves such as a laser, and the detection means (
The conventional method is to arrange the photomultiplier tube (photomultiplier tube) in such a way that it does not block the laser, and the distance from the point where the fluorescent light is emitted to the detection means is large, resulting in a significant drop in efficiency. There is also a method of guiding the fluorescent light using an optical fiber, but this also requires placement so that it does not interfere with the laser, and the coupling efficiency fd
, a significantly smaller and more precise alignment accuracy is required, resulting in significant costs. When using a phosphor layer in which phosphor powder is dispersed in an inder, it is difficult for the laser light to reach the deep part, and even if it does, it will scatter and cause 73 degrees of radiation. The light emitted from the deep H[ of the fluorescent plate is still absorbed by other powders, etc., so the luminous efficiency is low and the value becomes blurred.

G)) :? The purpose of the present invention is to improve the X-ray absorption efficiency of the phosphor and the detection efficiency of the light, thereby significantly reducing the amount of X-rays irradiated to the subject and achieving high detail. Image of image [elephant? ii
There are many things.

σ17) 'j:') bright light 15 formation and this purpose according to the invention is to emit 16'A to the phosphor plate.
After irradiating the image and once storing the radiographic image, the fluorescent plate is scanned with I electromagnetic waves, the luminescence emitted at that time is detected, and the radiographic image is taken by a radiographic image capturing device. f6j: (C, the phosphor layer of the above phosphor plate is fluorescent 1
This is achieved by providing a radiation image capturing device characterized in that it is made of a transparent film made of only a 4-diaphragm material.

100 million) HI emitted 3) Example Embodiments of the present invention will be described in detail below with reference to the drawings.

As an embodiment of the present invention, X-ray transmission images of the subject are written and stored on a fluorescent plate, and each image is scanned by a laser.
The flossing of '1' will be explained with reference to FIGS. 1 and 2.

The fluorescent plate has the structure shown in Fig. 1.
A ZeQ bright fluorescent film 2 of BaFCl:Eu was sputtered on top of the 20 μm J9. A sky due to Joule heat? When using JS, the film of uniform composition did not bend due to the difference in melting point of each component, and no significant fluorescence could be observed.

1. From the side of the light body 2 of this fluorescent plate 3,
9, the resulting X-ray image 5 is radiated by 1 (d).Then, in the Does it emit light?
The others are at a relatively shallow trap level l' (trap level). In this way, an image of the trap charge corresponding to X mM of fireflies is formed and stored.

Next, the HeNe laser 6 is scanned from the transparent phosphor layer 2#j of the phosphor plate 3 using a carbanomirror 7.

Then, the electrons in the shallow trap level are excited to the conduction band71
2. Eventually, it is captured by the luminescent center and produces fluorescence.

This light is captured by a detector (photomultiplier tube) 8, and when it is synchronized with laser scanning to form eight screens, an X-ray image corresponding to the amount of X-ray irradiation can be obtained. Here, the filter 9 is for cutting off the scattered light of the HeNe laser 6 and allowing only the fluorescent light to enter the detector.

Here, as the filter 8, an interference filter that passes BaFCJ:Eu's fluorescent light wavelength of 400 nrn was used.

The HeNe laser beam 6 is focused to about 50 μmO, and is scanned by a carbano mirror as shown in the front view in Figure 2 (b), and the scanning in the vertical direction is performed using a fluorescent plate as shown in the side view in Figure 2 (a). Move it in the direction of arrow Y and scoop it. A detector (photomultiplier tube) 8 is placed directly under the laser beam through a filter, close to the L arrow head plate, and has a dog edge that covers the cap 1 of the line running and can sufficiently capture the fluorescent light. It is something that

The time-series signal obtained by the detector 8 is input into 8i format after A/D conversion, and various computer processing such as gradation processing can be freely performed.

As a phosphor material with memory ability, ±ic, Ba
BaFCl:Ce, BaFBr:E in addition to FCl:Eu
u, La0Br:Tb, La0Br:Ce, La
0Br:Ce+Tb, La0Cl:Ce,
Tb + ZnS: Cu + Pb, etc. are promising.

The scanning electromagnetic wave is, of course, not limited to the IfeNe laser, but may be of any wavelength as long as the fluorescent light can be sufficiently separated by the filter 9 and the charges that are stably trapped at room temperature can be excited into the conduction band. I do not care.

The written image is not limited to the above-mentioned Xa image, but may also be a gamma ray or an ultraviolet image. It is applicable if the energy is greater than the bandgap of the phosphor.

(G) As described in the detailed description of the invention, the X-ray image reading device according to the present invention has a phosphor layer formed only from a phosphor material, and a fluorescent detection hand V (transmitted by electromagnetic waves). It is installed on the opposite side of the
The detection efficiency of -', qr;: :)'t'; is greatly improved.

4. E”l !If) (') ff1l single t
+r! 2'! ']bn 1 j'<+ Vj non-explosion゛'' ff showing the configuration diagram of the fluorescent plate and the layering method of the X-ray image
I, Figures 2 (a) and (b) are X of the present invention or image F
6) This is a diagram showing the Jj method.

1: ノ, す, ('E, 2: Fluorescent layer, 4: Subject, 5:
X thread 1; (, 6: laser light, 8: fluorescence detection means, 9: filter.

Claims (2)

[Claims] (1) Irradiate the fluorescent plate with the radiation bar V image and once make the above radiation image Mt: After the soil has blown up, it eclipses the n-base plate with electromagnetic waves, detects the fluorescence emitted at that time, In the radiation image reading device according to the above-mentioned radiation image reading device, the radiation image reading device is characterized in that the above-mentioned phosphor layer is made of a transparent film made only of phosphor material. reading device. (2) 1. A patent claim characterized in that the substrate of the same fluorescent light 4υ is made of a transparent material, and the fluorescent light detection means is arranged on the side opposite to the side on which the electromagnetic waves are scanned, based on the upper IIC Vi4+ light plate. A radiation image reading device plate according to item (1).