KR101369432B1 - Digital x-ray detector - Google Patents

Abstract

A digital X-ray detector comprises an outer case, a cover, an X-ray detecting panel, a light source unit, and a system board. The outer case has an internal space and an open upper part. The cover covers the opening in the upper part of the outer case. The X-ray detecting panel comprises: a pixel circuit substrate which is placed to face the cover inside the internal space of the outer case; a photoconductor which is formed in the upper part of the pixel circuit substrate; and an upper electrode which is formed in the upper part of the photoconductor. The light source unit emits light from the upper part of the X-ray detecting panel to the X-ray detecting panel inside the internal space of the outer case. The system board is placed in the lower part of the X-ray detecting panel inside the internal space of the outer case and is electrically connected with the X-ray detecting panel and the light source unit.

Description

Digital X-ray Detector {Digital X-ray Detector}

The present invention relates to a digital x-ray detecting apparatus, and more particularly, to a digital x-ray detecting apparatus having an improved structure for resetting.

The digital X-ray detector is divided into an indirect X-ray detector and a direct X-ray detector. In both X-ray detection apparatuses, a backlight device performs a reset role. In other words, the X-ray detection apparatus needs to be reset to detect a new image after detecting an image of a subject by being irradiated with X-rays. At this time, the back light device resets the X-ray detection device.

The X-ray detecting apparatus has a structure in which photoconductors are stacked on a thin film transistor (TFT) substrate, and the back light apparatus is positioned on the rear surface of the TFT substrate. This is because the TFT substrate has a structure in which TFTs are arranged on a transparent substrate, so that light of the backlight device can pass through the transparent substrate. Light emitted by the back light device is transmitted through the TFT substrate from the back of the TFT substrate and absorbed by the photoconductor, thereby completely removing and resetting the remaining charge of the photoconductor.

By the way, the general mass production type TFT is based on a-Si: H. Since a-Si (amorphous silicon) is also a material that generates a current in response to light, an unnecessary current component generated during the reset process may affect the quality of the X-ray image. In addition, since the back light device has a predetermined thickness and is installed on the rear surface of the TFT substrate, it may be an obstacle to manufacturing the X-ray detection device in a slim type, and a mechanical design for arranging and fixing the back light device is provided. It is necessarily accompanied. In addition, when the back light device is positioned on the back of a silicon-based opaque substrate on which a complementary metal oxide semiconductor (CMOS) transistor or the like is arranged, rather than a transparent TFT substrate, light is not transmitted through the opaque substrate. The entire remaining charge cannot be removed.

Japanese Patent Publication No. 2005-24368 (published Jan. 27, 2005)

An object of the present invention is to provide a digital X-ray detection apparatus that can improve the quality of the X-ray image, can be made slim, and can remove the remaining charge of the photoconductor even in the case of an opaque pixel circuit board.

According to an aspect of the present invention, there is provided a digital X-ray detecting apparatus including: an outer case having an inner space and an upper portion thereof opened; A cover covering an upper opening of the outer case; An X-ray detection panel including a pixel circuit board disposed to face the cover in an inner space of the outer case, a photoconductor formed on the pixel circuit board, and an upper electrode formed on the photoconductor; A light source unit radiating light from an upper side of the X-ray detection panel to the X-ray detection panel in an inner space of the outer case; And a system board disposed under the X-ray detection panel in an inner space of the outer case and electrically connected to the X-ray detection panel and the light source unit.

According to the present invention, since the light irradiated from the light source unit enters the photoconductor from the upper side of the X-ray detection panel without passing through the pixel circuit board, even if the pixel circuit board includes a material generating current in response to light, Unnecessary current components are not generated. Accordingly, the quality of the X-ray image may be secured.

According to the present invention, even when the pixel circuit board has a structure in which a CMOS transistor or the like is formed on an opaque substrate, the light irradiated from the light source unit can be smoothly introduced into the photoconductor to remove the remaining charge of the photoconductor. In addition, the structure for arranging and fixing the light source unit may be simplified, and may be advantageous to manufacture the X-ray detection apparatus in a slim type.

1 is a block diagram of a digital X-ray detection apparatus according to an embodiment of the present invention.
2 is a view for explaining the principle of removing the remaining charge of the photoconductor by the light source unit shown in FIG.
3 is an enlarged view of a region A in FIG. 1; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a digital X-ray detection apparatus according to an embodiment of the present invention. FIG. 2 is a view for explaining a principle of removing residual charge of a photoconductor by the light source unit shown in FIG. 1.

Referring to FIG. 1, the digital X-ray detecting apparatus 100 includes an outer case 110, a cover 120, an X-ray detecting panel 130, a light source unit 140, and a system board 150.

The outer case 110 has an inner space and has an open top. For example, the outer case 110 may have a flat bottom surface and four wall surfaces, and may have an open top. The outer case 110 may be made of a material such as carbon such that the X-ray detection panel 130 accommodated in the inner space, the light source unit 140, and the system board 150 may be alleviated from an external shock. .

The cover 120 is formed to cover the upper opening of the outer case 110. The cover 120 is fixed to the outer case 110 while completely covering the upper opening of the outer case 110. The X-rays are irradiated from the upper surface of the cover 120 to pass through the cover 120, and then enter the X-ray detection panel 130 in the outer case 110. The cover 120 may not only mitigate an impact from the outside, but may be made of a material such as carbon to transmit X-rays.

The X-ray detection panel 130 detects an X-ray image signal when X-ray irradiation of a subject. The X-ray detection panel 130 is disposed in the inner space of the outer case 110. The X-ray detection panel 130 includes a pixel circuit board 131, a photoconductor 132, and an upper electrode 133.

The pixel circuit board 131 is disposed to face the cover 120. For example, the pixel circuit board 131 may include an opaque base substrate and a pixel array formed on the base substrate. The base substrate may be a silicon (Si) based substrate. The pixel array includes one of a complementary metal-oxide semiconductor (CMOS) transistor, an N-channel metal oxide semiconductor (NMOS) transistor, a P-channel metal oxide semiconductor (PMOS), and a bipolar junction transistor (PMOS) on a base substrate. Each pixel circuit can be configured to include each pixel circuit. Of course, the pixel circuit board 131 may include a transparent substrate and a pixel array constituting each pixel circuit including a thin film transistor (TFT) on the transparent substrate.

The photoconductor 132 is formed on the pixel circuit board 131. The photoconductor 132 may be coated in a film form to cover the entire pixel array. The photoconductor 132 is a-Se, a-Si, crystal Si, CdTe, CdZnTe, As ₂ S ₃ , Sb ₂ S ₃ , As ₂ Se ₃ , Sb ₂ Se ₃ , ZnO, ZnSe, ZnTe, PbO, CdS It may be formed of any one selected from GaAs. The upper electrode 133 is formed on the photoconductor 132. The upper electrode 133 may be formed of an electrode having transparency. For example, the upper electrode 133 may be an indium tin oxide (ITO) or indium zinc oxide (IZO) transparent electrode. As another example, the upper electrode 133 may be formed of any one of Au, Ti, Cr, Cu, Al, Mo, Ag, Pt, and CNT to have a thickness of 50 to 200 nm. In this case, the upper electrode 133 may have a transmittance of about 70% or more. Accordingly, light emitted from the light source unit 140 may pass through the upper electrode 133 and enter the photoconductor 132.

When X-rays are irradiated on the X-ray detection panel 130, X-rays cause ionization in the photoconductor 132 to generate electrons and holes. Electrons move toward the upper electrode 133 by the voltage applied to the upper electrode 133, and holes are charged in the capacitor of the transistor. The amount of charge charged in the capacitor of the transistor is read by the system board 150, so that an X-ray image may be obtained.

The light source unit 140 is configured to radiate light from the upper side of the X-ray detection panel 130 to the X-ray detection panel 130 in the inner space of the outer case 110. After the X-rays are irradiated to the X-ray detection panel 130 through the subject to detect an image of the subject, as shown in FIG. 2, residual charges, for example, remain at the interface between the photoconductor 132 and the upper electrode 133. Electrons (R) will accumulate. At this time, when light is irradiated from the light source unit 140 to the photoconductor 132, the hole H among the electrons E and holes H generated by the light remains in the photoconductor 132. By being combined with, the remaining electrons R can be completely removed. Accordingly, the X-ray detection panel 130 may be reset to detect a new image.

As described above, the light irradiated from the light source unit 140 enters the photoconductor 132 from the upper side of the X-ray detection panel 130 and thus does not pass through the transistor of the pixel circuit board 131. Therefore, even if the transistor is made of a material that generates a current in response to light, such as a-Si (amorphous silicon), unnecessary current components by the transistor are not generated during the reset process. Therefore, the quality of the X-ray image may be secured.

In addition, even when the pixel circuit board 131 is not a structure in which a TFT is formed on a transparent substrate, but a structure in which a CMOS transistor or the like is formed on an opaque substrate, light emitted from the light source unit 140 smoothly flows into the photoconductor 132. It can be entered to remove the remaining charge in the photoconductor 132.

The system board 150 is disposed under the X-ray detection panel 130 in the inner space of the outer case 110. The system board 150 is electrically connected to the X-ray detection panel 130. When X-rays are irradiated to the X-ray detection panel 130 through the subject, the system board 150 supplies power to the X-ray detection panel 130 to control the output of the image signal for the subject. The system board 150 may receive an image signal output from the X-ray detection panel 130 and process a signal to acquire an X-ray image. In addition, the system board 150 is electrically connected to the light source unit 140. After the image of the subject is detected, the system board 150 may supply power to the light source unit 140, that is, the linear light source 141 to control the light from the line light source 141. have.

Meanwhile, referring to FIG. 3 along with FIG. 1, the light source unit 140 may include a line light source 141, a reflective film 142, and a diffusion film 143. The line light source 141 is disposed in at least one of the upper edge regions of the X-ray detection panel 130. That is, the line light source 141 is disposed so as not to cover the upper surface of the X-ray detection panel 130 that receives X-rays. When two line light sources 141 are provided, the line light sources 141 may be disposed to correspond to the edges of both sides of the X-ray detection panel 130 at an upper side of the X-ray detection panel 130. The line light source 141 may have a length corresponding to the edge length of the X-ray detection panel 130.

The reflective film 142 is formed on the lower surface of the cover 120. The diffusion film 143 is stacked below the reflective film 142. The reflective film 142 reflects the light emitted from the line light source 141 to the upper surface of the X-ray detection panel 130. The diffusion film 143 diffuses the light reflected by the reflective film 142 and evenly transmits the light to the upper surface of the X-ray detection panel 130. The diffusion film 143 may be formed in various patterns in a range capable of diffusing light. The reflective film 142 and the diffusion film 143 have an E-beam Evaporation, Thermal Evaporation method, film thermal bonding method, film printing method, spray method coating method, roll to roll method It may be formed in a variety of ways. The thicknesses of the reflective film 142 and the diffusion film 143 can be from 10 nm to several tens of mm.

The reflective member 144 may be installed in the line light source 141. The reflective member 144 may have a substantially semicircular cross-sectional area and have a structure extending along the length direction of the line light source 141. The reflective member 144 may face the concave surface spaced apart from the line light source 141 at regular intervals, and may be located closer to the inner wall of the case 110 than the line light source 141. Accordingly, the reflective member 144 may reflect the light emitted from the line light source 141 toward the lower surface of the cover 120 and the upper surface of the X-ray detection panel 130.

In the light source unit 140 having the above-described configuration, the line light source 141 is disposed on the edge of the X-ray detection panel 130 above the X-ray detection panel 130, and the reflective film 142 and the diffusion film 143 are covered by the cover 120. Since the bottom surface is formed of a thin film, the structure for positioning and fixing the light source unit 140 may be simplified, and may be advantageous for manufacturing the X-ray detection apparatus 100 in a slim shape.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

110. Outer case 120. Cover
130 X-ray detection panel 131 Pixel circuit board
132.Photoconductor 133.Top electrode
140. Light source 141. Line light source
142..Reflective film 143..Diffusion film
144. Reflective member 150. System board

Claims (5)

An outer case having an inner space and an upper portion opened;
A cover covering an upper opening of the outer case;
An X-ray detection panel including a pixel circuit board disposed to face the cover in an inner space of the outer case, a photoconductor formed on the pixel circuit board, and an upper electrode formed on the photoconductor;
Irradiating light from the upper side of the X-ray detection panel to the X-ray detection panel in an inner space of the outer case, the light source being at least one disposed in an upper edge region of the X-ray detection panel, and emitted from the line light source. A light source unit including a reflection member reflecting light toward the lower surface of the cover and the upper surface of the X-ray detection panel, a reflection film formed on the lower surface of the cover, and a diffusion film stacked below the reflection film; And
A system board disposed under the X-ray detection panel in an inner space of the outer case and electrically connected to the X-ray detection panel and the light source unit;
Digital X-ray detection apparatus comprising a. delete The method of claim 1,
The pixel circuit board,
An opaque base substrate,
Comprising any one of a complementary metal-oxide semiconductor (CMOS) transistor, an N-channel metal oxide semiconductor (NMOS) transistor, a P-channel metal oxide semiconductor (PMOS), a bipolar junction transistor (BMOS) transistor on the base substrate And a pixel array constituting each pixel circuit. The method of claim 1,
The upper electrode is a digital X-ray detection apparatus, characterized in that consisting of a transparent electrode. The method of claim 1,
The photoconductor is a-Se, a-Si, crystal Si, CdTe, CdZnTe, As ₂ S ₃ , Sb ₂ S ₃ , As ₂ Se ₃ , Sb ₂ Se ₃ , ZnO, ZnSe, ZnTe, PbO, CdS, GaAs Digital X-ray detection apparatus, characterized in that formed in any one selected.

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