KR100425379B1 - digital radiography detecting equipment and radiography detecting method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radiation detection apparatus and method, and more particularly, to an invention of a digital radiation detection apparatus and method for digitally detecting information on radiation by detecting an electrical signal without attaching a detection element per unit cell.

To this end, the present invention is a device for detecting radiation, X-ray receptor 11 which is excited by the radiation to generate electrons and hole pairs, and located above the X-ray receptor 11, and having different polarities The X-ray receptor 11 is composed of two sets of application electrodes 12 connected to a power source to form an electric field, and a collection electrode 13 for signal detection under the X-ray receptor. And a unit cell for detecting electrons and hole pairs generated by the application of X-rays at the collection electrode 13 in the form of an electrical signal by converting the voltage of the applied power supply unit 18 of the applied electrode 12. It provides a digital radiation detection device, characterized in that the unit cell is formed at right angles to the application electrode 12 and the collection electrode 13, the upper side of the application electrode 12 is connected to each other the power supply unit 18 By attaching Collection electrodes for simultaneously detecting a response signal an at each terminal with respect to the upper applied column of columns 8 having a different polarity and the applied power source conversion a in the applied power supply unit 18 A digital radiation detection device comprising a plurality of unit cell strings consisting of (1, 2, 3, 4, 5, 6), wherein the unit cell strings are collected in each unit cell string; Collecting electrode rows 1 ', 2', 3 ', 4', 5 ', and 6' having electrodes 1, 2, 3, 4, 5, and 6 connected to each other, and sequentially It provides a digital radiation detection device comprising a unit cell plate is composed of a plurality of applied electrode columns for converting, a plurality of unit cell arrays for detecting a sequential signal at each collection electrode.

In addition, in the method of detecting radiation, attaching two application electrodes 12 having different polarities to each other above the X-ray receptor and adding a power source to the application electrode to form an electric field; Generating an electron and hole pair by applying an X-ray, converting an electric field inside the X-ray receptor by converting a power source of the upper applied electrode, and below the X-ray receptor 11 And detecting the change in the electric field inside the X-ray receptor at the collecting electrode 13 located in the collecting electrode 13 in the form of an electrical signal.

Accordingly, there is an advantage in that the presence of radiation can be detected as an electrical signal and used as digital information without attaching a separate element to the unit cell for detecting radiation.

Description

Digital radiography detecting equipment and radiography detecting method

The present invention relates to an apparatus and a method for detecting a radiation, wherein two application electrodes for electric field formation are formed on an X-ray receptor and one collecting electrode is formed on an X-ray receptor to irradiate X-rays. Digital radiation that collects digital information from a unit cell array plate made by a method of detecting electron and hole pairs generated by a central X-ray receptor and a unit cell array or a planar array of unit cells. A detection apparatus and a radiation detection method.

BACKGROUND ART Generally, digital radiation detection apparatuses widely used include digital radiation detection apparatuses arranged with TFTs (Thin-Film-Transistors) as unit cells and digital radiation detection apparatuses arranged with CCDs as unit cells.

First, devices proposed using TFT as a unit cell are classified into a direct method and an indirect method.

Fig. 1 shows a radiation detection apparatus using a direct cell TFT as a unit cell, wherein an insulating layer T7 is formed on an X-ray receptor T6, and an application electrode T2 is attached to the upper part of the X-ray receptor T6. a unit cell in which a collection electrode T3, a signal storage capacitor T4, and a TFT T5, which is a signal detection element, are bonded to a lower portion of the x-ray receptor; It is used to show the appearance.

In FIG. 1, when the X-ray is incident, electrons of the X-ray receptor T6 are excited to generate electrons and electron-hole pairs. When a strong electric field is formed through the upper electrode T2, the electrons and The movement of charges occurs due to the movement of the polarity of the holes.

This flow of charge is accumulated in a signal storage capacitor T4 through the collection electrode T3, and this amount of charge is recognized as an electric digital signal through the TFT.

After forming a plurality of unit cells in a plane and forming them with a radiation detection device, a method of obtaining X-ray image information using each digital signal collected in each unit cell as a source of an image signal is a TFT digital method. .

The indirect TFT unit cell is formed by forming an X-ray receptor with a fluorescent material and attaching a TFT and a light receiving element such as a photodiode to the lower portion of the X-ray receptor.

The change of charge caused by the X-ray irradiation on the unit cell causes luminescence on the fluorescent material, which is an X-ray receptor, and the light generated by the luminescence is converted into an electrical signal through a photodiode, such as a light receiving element. And detected as a digital signal by the TFT.

These unit cells are arranged in a plane to be used as a digital image detection device.

Next, the proposed device using a CCD image sensor as a unit cell uses a fluorophore as an X-ray receptor, attaches a condenser at the bottom, and arranges the unit cells in which a CCD is formed as a signal detector at the bottom. It is a device used as a detector plate.

The light concentrating device has been proposed to use a light receiving element such as a photodiode or attach an optical fiber to connect to a CCD or to focus on a LENS.

FIG. 2 illustrates a device using an optical fiber as a light collecting device among radiation detection devices having a CCD image sensor as a unit cell, and FIGS. 2 (a) and 2 (b) show a basic unit cell, and FIG. 2 (c). Denotes a radiation arranging apparatus in which a plurality of unit cells are formed in a planar arrangement.

The unit cell of FIG. 2 (a) is a light collecting device that detects light under the phosphor C2 used as the X-ray receptor, and forms the lens C4 and attaches the CCD C1 to the lower portion thereof. The X-ray receptor, which is a fluorescent material, is excited by the X-rays to convert energy into light, which is then converted into an electrical signal by the CCD and used as a digital image signal.

The unit cell of FIG. 2 (b) is a light collecting device that detects light in the lower portion of the phosphor C2 used as the X-ray receptor, and forms the optical fiber C5 and attaches the CCD C1 to the lower portion thereof. The X-ray receptor, which is a fluorescent material, is excited by the X-rays to convert energy into light, which is then converted into an electrical signal by the CCD and used as a digital image signal.

(c) is a shape in which a plurality of unit cells of (b) are arranged in a plane, and each signal detected in each unit cell is detected as a digital video signal. One information for each unit cell is obtained to obtain digital information. It can be seen that the CCD, which is one signal detection element per unit cell, is required to obtain.

In the conventional technique described above, problems are pointed out in terms of cost and efficiency due to the high cost and limited resolution required for manufacturing TFTs, which are required for each unit cell, and the CCD is also compared with the cost of one element attached to each unit cell. The conversion efficiency of phosphors is low and there are problems such as distortion due to geometric distortion and noise due to light scattering.

The present invention is to solve the above problems, without a separate signal detection device such as TFT or CCD in the unit cell, the unit cell consisting of only two applying electrodes and the collection electrode as an electric signal changed by the X-ray power supply of the applied electrode Detection by means of a method of converting the current, the array direction of the applying electrode and the collecting electrode are perpendicular to each other, and the sequential inputs (a, b, c, d ..) are sequentially applied to the horizontal applying electrode in a vertical direction. Output according to the sequential input at the collecting electrode in the direction (a1, a2, a3, a4 ../ b1, b2, b3, b4 ../ c1, c2, c3, c4 ../ d1, d2, d3, d4 .. It is an object of the present invention to provide a digital radiation detection device and a radiation detection method for detecting a digital image signal in a manner that detects).

1 is a cross-sectional view of a radiation detection apparatus using a direct cell TFT as a unit cell according to the prior art;

2 is a cross-sectional view of a radiation detection apparatus using a CCD image sensor as a unit cell according to the prior art;

Figure 3 is a unit cell cross-sectional view of the digital radiation detection apparatus according to the present invention

4 is a perspective view of a unit cell of a digital radiation detection apparatus according to the present invention;

5 is a perspective view of a unit cell array of a digital radiation detection apparatus according to the present invention;

6 is a perspective view of a unit cell plate of the digital radiation detection apparatus according to the present invention

7 is a graph of voltage response experiment data of a unit cell according to the present invention;

1, 2, 3, 4, 5, 6: Collection electrodes 1 ', 2', 3 ', 4', 5 ', 6': Collection electrode columns 8: Upper applied electrode string 9: One terminal 11: Receptor 12: Applying electrode

13 collection electrode 15 substrate

18: power supply a: power supply conversion signal

an: response signal E: applied voltage input

In order to achieve the above object, the present invention provides an apparatus and method for detecting radiation.

That is, in the digital radiation detection apparatus, X-ray receptor which is excited by X-ray and produces | generates an electron and a hole pair; An application electrode positioned above the X-ray receptor and forming a pair of two; An application power supply unit connected to the application electrode, a constant voltage being applied to apply different polarities to the application electrode, and a voltage being converted to detect an electrical change inside the X-ray receptor changed by the X-ray; And a collection electrode positioned below the X-ray receptor and configured to detect an electrical change in the X-ray receptor as an electrical signal when the voltage of the applied power supply unit is changed. Is to be a technical summary.

In addition, there is provided a radiation detection method, comprising: an electric field forming step of attaching two application electrodes having different polarities to an upper side of an X-ray receptor and adding an electric power to the application electrodes to form an electric field; An electron and hole generating step of generating an electron and a hole pair by applying an X-ray to the X-ray receptor; An applied voltage converting step of converting an electric field inside the X-ray receptor by converting a power source of the upper applied electrode; The radiation detection method comprising a signal collection step of detecting the change in the electric field inside the X-ray receptor in the collection electrode in the form of an electrical signal in the collecting electrode located below the X-ray receptor is a technical gist.

Wherein the X-ray receptor of the unit cell has a hexahedron as a basic structure; The application electrodes are spaced apart from the left and right sides of the upper edge of the X-ray receptor and contacted back and forth; The collection electrode is configured to be in contact with the left and right of the lower edge of the X-ray receptor and spaced apart from the front and rear to form a unit cell, characterized in that the perpendicular to the applied electrode to provide a digital radiation detection apparatus. To; The unit cells are connected in contact with each other so that the application electrodes are connected to each other to form a plurality of unit cells in a row; An applied power source is attached to one terminal of the upper side applied electrodes connected in series by the unit cell row; It is also preferable that the digital radiation detection device comprises a; collecting electrodes for detecting a signal at each terminal at the same time with respect to the applied power conversion of the applied electrode.

In addition, the unit cell rows are connected to each collection electrode of the unit cell row to be connected to each other to form a unit cell plate formed of a plurality of unit cell rows; A sequential applied voltage input unit for sequentially applying an applied voltage to the applied electrodes of each unit cell column; The digital radiation detection device is characterized in that it comprises a collection electrode string for detecting the sequential response signal to the sequential voltage change of the applied voltage portion.

Accordingly, there is an advantage in that the presence of radiation can be detected as an electrical signal and used as digital information without attaching a separate element to the unit cell for detecting radiation.

If described in detail with reference to the accompanying drawings the operation and embodiments of the present invention.

3, 4, 5, and 6 illustrate a digital radiation detection apparatus according to the present invention. FIGS. 3 and 4 attach two dual electrodes 12 to an upper portion of the X-ray receptor, and a lower portion thereof. 5 shows unit cells having a collection electrode 13 attached thereto, and FIG. 5 shows unit cell arrays arranged in a row to explain a method of arranging the unit cells by means of obtaining digital information from the unit cells. FIG. 6 illustrates a method of obtaining digital information about a plane in the unit cell, in which the unit cell arrays are arranged in a plurality of planes and molded into a radiation detection apparatus.

In FIG. 3, after applying a high voltage to the upper applying electrode 12 located above the X-ray receptor, when the X-ray beam is irradiated, the x-ray receptor 11 is excited to form an electron-hole pair. pair) occurs, and when the voltage of the applied power supply unit 18 is changed, an electrical change occurs inside the X-ray receptor, and the electrical change can be detected by the collection electrode 13. The detected signal is transmitted to the desired analyzer or the like through the substrate 15.

That is, the unit cell generates a constant electric field inside the X-ray receptor by applying a constant voltage to the upper applied electrode in the field generation step, and generates an electron and hole pair by X-ray irradiation in the electron and hole generation step, An apparatus for implementing a radiation detection method of converting a power applied to an upper applied electrode in an applied voltage conversion step to generate a change in an electric field inside the X-ray receptor, and detecting an internal signal of the X-ray receptor in a signal detection step.

7 shows the experimental data of the unit cell and maintains the voltage of the applied power supply unit 18 that applies the voltage to the applying electrode 12 of FIG. 1 constant at 1 kV, irradiates X-rays, and then applies the applied electrode 12 to the applying electrode 12. When the applied voltage of the applied power supply unit 18 is stepped down to 600 V, the signal detected by the collecting electrode 13 is a graph of the response signal according to the irradiation intensity of the X-ray.

The above experiment is merely an exemplary description for demonstrating the effects of the present invention, but the scope of the present invention is not limited to this experiment.

The x-axis of the graph is the time axis, and the y-axis is the voltage response detected by the collecting electrode.

According to this, it can be seen that the maximum value of each signal value detected when the irradiation intensity of the X-ray is increased by 20 kVp from 40 kVp to 120 kVp is different depending on the irradiation intensity of the X-ray.

This proves that the unit cell functions to detect X-ray radiation.

That is, FIG. 7 shows that the detection amount of the collection electrode is different according to the irradiation intensity of the radiation when the voltage variation of the applied power supply unit 18 is constant. This variation can be used as a source of information on radiation. .

In order to obtain digital information from the unit cell, the basic unit cell has a rectangular shape, and two application electrodes 12 located above the X ray receptor are spaced apart from the front and rear edges of the X ray receptor and are separated from the left and right corners. The collection electrodes are formed to be in contact with each other, and the collecting electrodes are formed to be spaced apart from each other and the front and rear edge portions are in contact with each other so as to form a unit cell formed at right angles to the applying electrodes.

In the arrangement of a plurality of unit cells configured as shown in FIG. 4, when the upper two application electrodes 12 are arranged in such a manner as to be in contact with each other, they can be formed into a unit cell array as shown in FIG. 8, one terminal 9 is connected to the applied power supply unit 18, and at the same time, power is applied by the applied power conversion signal a, and a plurality of lower collection electrodes detect one signal in each unit cell. As a result, all the signals of the unit cell arrays arranged in line by the conversion signal of one applied voltage are simultaneously detected one by one at each collection electrode to obtain digital information.

Accordingly, a plurality of response signals, such as the number of unit cells, are simultaneously detected in a unit cell sequence forming one row.

In the arrangement of a plurality of unit cell rows, the arrangement of the collection electrodes of each unit cell row in a manner of contacting and connecting the plurality of unit cells is shown in FIG.

In FIG. 6, each response signal is divided into a sequential response and a simultaneous response to generate an overall response, and the sequential response is an applied power conversion signal (a, b) applied to the applying electrode by the applied voltage input unit (E). , c, d) refers to response signals a1, b1, c1, and d1 that are sequentially detected with respect to one collection electrode 1 'when a time difference is sequentially applied to each of the applied electrodes. Simultaneous response is that the response signals a1, a2, a3, a4, a5, and a6 correspond to the number of collecting electrodes, that is, the number of unit cells constituting the unit cell sequence, with respect to one applied power supply conversion signal a. Means the response detected by the collection electrode, each unit cell provides a single response signal by the sequential response and the simultaneous response, the sequential input (a, b, c, d) is applied to the unit cell sequence , The electrical signals are detected by the collection electrodes at each sequential time. In this way, the entire signal that is sequentially responded can be detected as a digital signal.

By arranging a plurality of unit cells in a plane number in the same manner as described above, digital information on the incident area of radiation is obtained and used as a digital radiation detection device.

Using this digital signal as a visual information source (soucre) of the imaging device, it can be used not only as a device for obtaining digital radiation image information, but also as an X-ray detector for detecting foreign substances in food, or a search device for airports and other restricted areas. And medical X-ray imaging.

In addition, the digital detection device using a unit cell sequence is considered to be applied as a detector of a CT (Computed Tomography) and a detector of a digital mammography system.

When the present invention having the above-described configuration is used as a radiation detection apparatus and digital information is obtained by the above-described detection method, an application electrode and a collection electrode are not attached to each unit cell without attaching a separate element for detecting a digital signal per unit cell. Digital signal can be detected by itself, and the cost of manufacturing a digital radiation detection device by an expensive element can be reduced, and when the digital signal is used as a visual information source of an imaging device, a device for obtaining digital radiation image information Can be utilized as

Claims (5)

delete An X-ray receptor 11 excited by an X-ray to generate electrons and hole pairs, an application electrode 12 positioned above the X-ray receptor 11, and an application power supply connected to the application electrode 12 In the digital radiation detection device formed of a unit cell comprising 18 and a collection electrode 13 positioned below the X-ray receptor 11, The X-ray receptor 11 has a hexahedron as a basic structure, The application electrodes 12 are formed to be spaced apart in parallel in a set of two, spaced apart from the left and right of the upper corner of the X-ray receptor, and contacted with the front and rear, The applied power supply unit 18 is connected to the set of applied electrodes 12 to form a closed circuit to apply voltages of different polarities to the applied electrodes 12 and to change the electric change inside the X-ray receptor changed by the X-rays. Applying a converted voltage to be detected, The collection electrode 13 is formed to be in contact with the left and right of the lower edge of the X-ray receptor and spaced apart from the front and rear, and formed in a direction perpendicular to the applying electrode 12, the conversion of the power supply unit 18 A digital radiation detection device including a unit cell, characterized in that it detects an electrical change in the X-ray receptor 11 changed by a voltage as an electrical signal; 3. The unit cell according to claim 2, wherein the unit cells are connected in contact with each other so that the application electrodes 12 are connected to each other to form a plurality of unit cells in a row; An applied power supply unit 18 is attached to one terminal 9 of the upper side applied electrode rows 8 connected in series by the unit cell rows; And collecting electrodes (1, 2, 3, 4, 5, 6) for simultaneously detecting a response signal (an) at each terminal with respect to the applied power conversion signal (a) of the applied electrode. Digital Radiation Detector. 4. The unit cell array of claim 3, wherein the unit cell rows comprise unit cell plates formed of a plurality of unit cell rows by contacting each collection electrode (1, 2, 3, 4, 5, 6) of the unit cell row to be connected to each other; A sequential applied voltage input unit E for sequentially applying an applied voltage to the applied electrodes of each unit cell column one by one; Digital radiation detection, comprising collection electrode columns (1 ', 2', 3 ', 4', 5 ', 6') for detecting sequential response signals for sequential voltage changes in the applied power supply. Device. delete