X-ray detector

Abstract

The X-ray detector, which detects X-rays to generate corresponding output signals, includes: a TFT array including a plurality of pixel TFT circuits that respectively generate the output signals based on the detected X-ray intensities; a gate circuit configured to apply a gate signal for driving the plurality of pixel TFT circuits to the TFT array; and a readout circuit configured to be able to receive the output signals generated at the plurality of pixel TFT circuits and to transfer the output signals to the outside. The grid circuit comprises a grid chip on film which is configured to generate the grid signal and apply the grid signal to the TFT array; and the grid connection FPCB is in circuit connection with the grid chip-on-film so as to receive a driving signal for generating the grid signal and transmit the driving signal to the grid chip-on-film. The grid chip on film and the grid connection FPCB are respectively configured along different sides of the X-ray detector.

Description

Technical Field

[0001] The present invention relates to X-ray detectors. Background Art

[0002] X-ray imaging devices that use X-rays to obtain images of the inside of an object are used in various fields such as medical and industrial fields. The X-ray imaging device includes an X-ray source that generates X-rays and an X-ray detector that detects the X-rays that have passed through the object.

[0003] The X-ray detector detects X-rays passing through an object in pixel units and generates an electrical signal according to the size of the detected X-rays. For example, the X-ray detector includes: a charge generation layer that generates charges according to the size of the detected X-rays; and a TFT array layer, including a plurality of thin film transistors (TFTs) arranged in a matrix form to generate electrical signals according to the size of the generated charges. On the other hand, the TFT array layer requires a gate circuit and a readout circuit, wherein the gate circuit is used to input the gate electrode of the driving TFT, and the readout circuit is used to output a readout signal as an output signal. The gate circuit is configured to receive a driving signal from a controller, thereby generating a gate signal for driving each TFT, and can be applied to each TFT. This gate circuit can be embodied in the form of a gate board or a gate COF (Chip On Film). The gate board is difficult to realize miniaturization design due to its large size. In particular, when the gate board is used, there is a problem that it cannot be embodied in the form of a flexible detector. In order to solve this problem, a technology of using a gate chip-on-chip film and a gate connection FPCB (flexible printed circuit board) for circuit connection therewith to replace the gate plate has been introduced.

[0004] The gate connection FPCB receives a driving signal from an external driving circuit and transmits it to the gate chip-on-chip film. The gate chip-on-chip film generates a gate signal with the help of the driving signal transmitted from the gate connection FPCB and applies it to each TFT. At this time, the gate connection FOCB is formed in a relatively longer manner than the gate chip-on-chip film in order to connect to the external driving circuit, and it is necessary to have a connector for circuit connection with the external driving circuit, so it has a relatively long length. For example, the readout circuit, since the readout chip-on-chip film is formed along one side of the TFT detector, the gate chip-on-chip film and the gate connection FPCB are formed together along the other side of the TFT detector. Therefore, the length of the TFT detector toward the direction where the gate chip-on-chip film and the gate connection FPCB are formed becomes larger, making it difficult to achieve a miniaturized design. In addition, since the gate connection FPCB is formed together with the relatively compact gate chip-on-chip film, the possibility of miniaturization is ultimately offset by the use of a compact gate chip-on-chip film.

[0005] Prior art literature

[0006] Patent Literature

[0007] (Patent Document 1) Korean Registered Patent Gazette No. 10-1139408 (Published on April 27, 2012) Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The problem to be solved by the present invention is to provide an X-ray detector which can optimize the connector structure of a thin film transistor to achieve a miniaturized design and can effectively adhere to an object such as a pipe to perform imaging.

[0010] Means used to solve problems

[0011] The X-ray detector for detecting X-rays to generate corresponding output signals according to the embodiment of the present invention comprises: a TFT array, comprising a plurality of pixel TFT circuits respectively generating the output signals based on the detected X-ray intensity; a gate circuit, configured to apply a gate signal for driving the plurality of pixel TFT circuits to the TFT array; and a readout circuit, configured to receive the output signals generated in the plurality of pixel TFT circuits and transmit them to the outside. The gate circuit comprises: a gate chip-on-film, configured to generate the gate signal and apply it to the TFT array; and a gate connection FPCB, which is circuit-connected to the gate chip-on-film so as to receive the drive signal for generating the gate signal and transmit it to the gate chip-on-film. The gate chip-on-film and the gate connection FPCB are respectively configured along different sides of the X-ray detector.

[0012] The gate connection FPCB may be arranged along the same side of the readout circuit and the X-ray detector.

[0013] The gate chip-on-film may be arranged along one side of the X-ray detector, and the gate connection FPCB and the readout circuit may be arranged together along an adjacent side of the X-ray detector on which the gate chip-on-film is arranged.

[0014] The readout circuit may be formed by a readout chip-on-film.

[0015] The X-ray detector may be composed of a bendable flexible detector.

[0016] The X-ray detector of an embodiment of the present invention includes: a TFT array including a plurality of pixel TFT circuits that respectively generate output signals based on the intensity of the detected X-rays; a gate circuit configured to apply a gate signal for driving the pixel TFT circuit to the TFT array; and a readout circuit configured to read the output signal for external transmission. The gate circuit includes: a gate connection circuit that receives a drive signal from the outside; and a gate signal generation circuit that receives the drive signal from the gate connection circuit to generate the gate signal. The TFT array is configured to form a square area. The gate connection circuit and the readout circuit are configured together along one side of the square area of ​​the TFT array, and the gate signal generation circuit is configured along an adjacent side of one side of the square area where the gate connection circuit and the readout circuit are configured.

[0017] The gate connection circuit may be configured in the form of FPBC, and the readout circuit and the gate signal generation circuit may be configured in the form of flip-chip films, respectively.

[0018] Effects of the Invention

[0019] According to the present invention, the gate connection FPCB is spatially separated from the gate chip-on-chip film and configured along the same side of the TFT X-ray detector together with the readout chip-on-chip film, whereby when designing a printed circuit board, the components can be configured without interference and a miniaturized design of the X-ray detector can be achieved.

[0020] Furthermore, a relatively long gate connection FPCB is spatially separated from a relatively short gate chip-on-chip film and arranged along the other side, thereby minimizing the length of the portion of the TFT X-ray detector that is directed outward in the direction in which the gate chip-on-chip film is formed, thereby allowing the TFT X-ray detector to be placed as close as possible to an object such as a pipe, thereby achieving effective imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The cross-sectional view briefly shows a direct-mode X-ray detector according to an embodiment of the present invention.

[0022] Figure 2 The cross-sectional view briefly shows an indirect X-ray detector according to another embodiment of the present invention.

[0023] Figure 3 FIG. 1 is a diagram briefly showing an X-ray detector according to an embodiment of the present invention.

[0024] Description of Reference Numerals

[0025] 10: X-ray detector

[0026] 11: Substrate

[0027] 13: TFT array

[0028] 15: Charge collection unit

[0029] 17: Photoconductor layer

[0030] 18: Electrical insulation layer

[0031] 19: Upper electrode

[0032] 21: Power supply

[0033] 23: Pixel TFT circuit

[0034] 231: Storage capacitor

[0035] 233: TFT switch element

[0036] G: Gate terminal

[0037] S: source terminal

[0038] D: Data terminal

[0039] 235: Gate line

[0040] 237: Data line

[0041] 31: Gate circuit

[0042] 33: Readout circuit

[0043] 311: Chip-on-gate film

[0044] 313: Gate connection FPCB

[0045] 314: Connector

[0046] 331: Connector

[0047] 101, 102: The edge of the X-ray detector DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention is not limited to the embodiments described above, but can be embodied in many different forms.

[0049] The X-ray detector of the embodiment of the present invention may be a direct conversion X-ray detector or an indirect conversion X-ray detector. Figure 1 A direct X-ray detector is shown exemplarily in FIG. Figure 2 An indirect X-ray detector is shown exemplarily in FIG.

[0050] Reference Figure 1 The X-ray detector 10 of one embodiment of the present invention may be a digital X-ray detector that directly converts X-ray photons into electric charges, that is, a direct X-ray detector. In addition, the X-ray detector 10 of the embodiment of the present invention may be a flexible X-ray detector that is bendable.

[0051] Reference Figure 1 According to the X-ray detector 10 of the embodiment of the present invention, the TFT array 13, the charge collection unit 15, the photoconductor layer 17 and the upper electrode 19 can be sequentially formed on the flexible substrate 11. For example, the substrate 11 can be formed of a flexible synthetic resin material, and thus, the X-ray detector 10 of the embodiment of the present invention can be embodied as a flexible detector.

[0052] When X-rays are incident while a high voltage of a power source 21 is applied to the upper electrode 19, the photoconductor layer 17 generates charges. The photoconductor layer 17 may be formed of a material that directly converts X-ray photons into charges, such as amorphous selenium, lead oxide (PbO), thallium bromide (HgI2), or the like, i.e., a photoconductor. At this time, an electrical insulating layer 18 may be formed between the upper electrode 19 and the photoconductor layer 17 so that the upper electrode 19 and the photoconductor layer 17 are electrically insulated from each other.

[0053] The TFT array 13 may include a plurality of pixel TFT circuits 23 and be formed in the form of a flexible panel. As is well known, a plurality of pixel TFT circuits 23 can be arranged in a matrix form in pixel units, whereby the TFT array 13 can form a square-shaped area. Each pixel TFT circuit 23 includes a storage capacitor 231 and a TFT switch element 233. The TFT switch element 233 includes a gate terminal G, a data terminal D, and a source terminal S, and the source terminal S is connected to the storage capacitor 231. The gate terminal G is connected to the gate circuit, i.e., the gate chip on film (COF) 311, through the gate line 235, and the data terminal D is connected to the readout circuit, i.e., the readout IC chip on film 33, through the data line 237.

[0054] If charges are generated in the photoconductor layer 17 by the incidence of X-rays, positive charges are collected by the charge collection unit 15 among the generated charges. Further, the positive charges gathered in the charge collection unit 15 are stored in the storage capacitor 231 of the pixel TFT circuit 23. In this process, the amount of charges generated by the photoconductor layer 17 becomes different according to the intensity of the incident X-rays, and therefore, the amount of charges finally stored in the storage capacitor 231 becomes different according to the intensity of the X-rays. If a gate signal, that is, a scanning signal is applied to the gate terminal G through the gate line 235, the TFT switching element 233 is turned on, thereby outputting an output signal corresponding to the amount of charges stored in the storage capacitor 231 to the data line 237 through the data terminal D. In this way, an output signal corresponding to the intensity of the X-rays detected in each pixel is output, and the output signal can be used to generate an X-ray image. On the other hand, although not shown, it is well known that a circuit element for initializing the storage capacitor 231 after the output signal is output by turning on the TFT switch element 233 , for example, a switch element may be connected in parallel with the storage capacitor 231 .

[0055] On the other hand, refer to Figure 2 , the X-ray detector 10 of another embodiment of the present invention may be a digital X-ray detector that converts X-rays into visible light and then changes the photons of visible light into electric charges, that is, an indirect method. Figure 1 The same parts of the X-ray detector of the direct method described here are denoted by the same reference numerals, and repeated descriptions are omitted.

[0056] Reference Figure 2The indirect X-ray detector 10 includes: a scintillator layer 37 that converts incident X-rays into visible light; and a photodiode layer 35 that generates charges in the visible light converted by the scintillator layer 37. The scintillator layer 37 can be formed by a scintillator that releases visible light proportional to the incident X-rays. The photodiode layer 35 can be formed by an amorphous silicon photodiode and converts the visible light released by the scintillator layer 37 into charges. As in the aforementioned embodiment, the charges generated in the photodiode layer 35 are detected by the TFT array 13.

[0057] Below, refer to Figure 3 , a gate circuit 31 for applying a gate signal to the gate line 235 and a readout circuit 33 for receiving an output signal from the data line 237 and outputting it to the outside are described.

[0058] Figure 3 2 shows a top view of the TFT array 13 of the X-ray detector 10. The TFT array 13 is configured to have a square shape as a whole. As described above, the TFT array 13 includes a plurality of pixel TFT circuits 23 arranged in a matrix.

[0059] The gate circuit 31 is configured to apply a gate signal to the gate line 235 connected to the pixel TFT circuit 23. According to an embodiment of the present invention, the gate circuit 31 is divided into two parts, namely, a gate COF 311 and a gate connection FPCB (flexible printed circuit board) 313, and the gate COF 311 and the gate connection FPCB 313 are respectively configured along different sides 101 and 102 of the X-ray detector 10. It can be understood that the side of the X-ray detector 10 is the side of the square area of ​​the TFT array 13. The gate connection FPCB 313 is connected to the external controller signal through the connector 314, and receives the driving signal from the controller to transmit it to the gate COF 311, and the gate COF 311 generates a gate signal of the received driving signal and applies it to the gate line 235.

[0060] The readout circuit 33 may be implemented in a chip-on-film form, and thus, the readout circuit 33 may be referred to as a readout COF. The readout COF 33 is configured to be connected to an external image signal processing unit through a connector 331 to transmit output signals to the image signal processing unit.

[0061] According to an embodiment of the present invention, the readout COF 33 may be arranged along one side of the X-ray detector 10. At this time, the gate chip-on-film 311 of the gate circuit 31 may be arranged along one side 101 of the square-shaped X-ray detector 10, and the gate connection FPCB 313 of the gate circuit 31 and the readout COF 33 may be arranged along the side 102 adjacent to the side 101 of the X-ray detector 10 on which the gate chip-on-film 311 is arranged. According to an embodiment of the present invention, considering that the gate connection FPCB 313 and the readout COF 33 are formed in a relatively long manner in order to connect signals with an external controller or an image signal processing unit, and connectors 314 and 331 for connection are required, the gate connection FPCB 313 and the readout COF 33 may be arranged on the same side 102 to greatly reduce the height direction of the X-ray detector 10, Figure 3 The size in the up-down direction in the X-ray detector 10 is thus minimized because the gate chip-on-film 311 forms a portion protruding toward the outside of the TFT array 13 in the height direction of the X-ray detector 10. Therefore, the length in the height direction of the portion protruding toward the outside of the TFT array 13 as the X-ray detection area can be minimized. This means that the X-ray detector 10 is very close to the object in the height direction, thereby enabling imaging to be achieved in a state where the X-ray detector 10 is very close to the connection portion of the T-shaped piping. Furthermore, the gate chip-on-film 311 and the gate connection FPCB 313 can be arranged along different sides of the X-ray detector to prevent mutual interference.

[0062] Although the above description is made by taking a direct X-ray detector as an example, it can be understood that the present invention can be applied to an indirect X-ray detector having a TFT array. In addition, as described above, the X-ray detector of the embodiment of the present invention can be embodied as a bendable flexible detector, or can be an X-ray detector in a rigid body form with TFTs formed on a glass substrate.

[0063] Although the embodiments of the present invention have been described above, the protection scope of the present invention is not limited thereto, and various modifications made by ordinary technicians using the basic concept of the present invention defined in the claims also fall within the protection scope of the present invention.

Claims

1. An X-ray detector, which detects X-rays to generate corresponding output signals, characterized in that: include: a TFT array including a plurality of pixel TFT circuits that respectively generate the output signals based on the detected X-ray intensities; a gate circuit configured to apply a gate signal for driving the plurality of pixel TFT circuits to the TFT array; as well as a readout circuit configured to receive the output signals generated by the plurality of pixel TFT circuits and transmit them to the outside, The gate circuit comprises: A gate chip-on-chip film is configured to generate the gate signal and apply it to the TFT array; as well as The gate connection FPCB is circuit-connected with the gate chip-on-film so as to receive a driving signal for generating the gate signal and transmit it to the gate chip-on-film. The gate chip-on-film and the gate connection FPCB are respectively arranged along different sides of the X-ray detector.

2. The X-ray detector according to claim 1, characterized in that: The gate connection FPCB is arranged along the same side of the readout circuit and the X-ray detector.

3. The X-ray detector according to claim 2, characterized in that: The gate chip-on-chip film is arranged along one side of the X-ray detector, The gate connection FPCB and the readout circuit are arranged together along an adjacent side of a side of the X-ray detector on which the gate chip-on-film is arranged.

4. The X-ray detector according to claim 3, characterized in that: The readout circuit is formed by a readout flip chip.

5. The X-ray detector according to claim 1, characterized in that: The X-ray detector is composed of a bendable flexible detector.

6. An X-ray detector, characterized in that: include: A TFT array including a plurality of pixel TFT circuits that respectively generate output signals based on the intensity of the detected X-rays; a gate circuit configured to apply a gate signal for driving the pixel TFT circuit to the TFT array; as well as a readout circuit configured to read out the output signal for transmission to the outside, The gate circuit comprises: A gate connection circuit receives a driving signal from the outside; as well as a gate signal generating circuit, receiving the driving signal from the gate connecting circuit to generate the gate signal, The TFT array is configured to form a square area, The gate connection circuit and the readout circuit are arranged together along one side of the square area of ​​the TFT array. The gate signal generating circuit is arranged along a side adjacent to one side of the square region where the gate connecting circuit and the readout circuit are arranged.

7. The X-ray detector according to claim 6, characterized in that: The gate connection circuit is configured in the form of FPBC. The readout circuit and the gate signal generating circuit are each configured in a chip-on-film form.

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