Dynamic X-ray detection panel, X-ray detector, and method of driving the same

Abstract

The present invention discloses a dynamic X-ray detection panel, an X-ray detector including the dynamic X-ray detection panel, and a method for driving the X-ray detector. The method for driving the X-ray detector is a method for driving a dynamic X-ray detector including the X-ray detection panel. The X-ray detection panel includes a plurality of pixels arranged in a matrix, each pixel including a readout thin-film transistor, a reset thin-film transistor, and a photodiode. Line reset, window timing, and readout are performed for the plurality of pixels in each row.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent document claims priority to and the benefit of Korean Patent Application No. 10-2021-0122648, filed on September 14, 2021, the entire disclosure of which is incorporated by reference for all purposes as if fully set forth herein. Technical Field

[0003] Embodiments of the present invention relate to an X-ray detection panel, an X-ray detector comprising the X-ray detection panel, and a method for driving the X-ray detector, and more specifically, to a high frame rate dynamic X-ray detection panel, an X-ray detector comprising the high frame rate dynamic X-ray detection panel, and a method for driving the X-ray detector. Background Art

[0004] X-ray detectors are used not only in medical equipment for X-ray diagnostic imaging in hospitals and dental clinics, but also for internal defect detection in electric vehicle batteries, semiconductors, electronic components, construction, aviation, ships, etc., in industrial equipment for inspecting the loading and unloading of cargo at airports and port facilities, and in military equipment for detecting hazardous substances such as explosives.

[0005] Dynamic X-ray detectors are used in medical and industrial imaging systems, and their use for industrial purposes is increasing, especially in non-destructive testing, where product reliability is crucial (e.g., electric vehicle batteries or semiconductors). For medical purposes, dynamic X-ray detectors are used in, for example, C-arm CT, cone-beam CT, and breast cancer diagnostic CT.

[0006] Dynamic X-ray detectors need to have high frame rates, low image lag, and low ghost images in order to achieve high frame rate images.

[0007] The X-ray detector includes an X-ray detection panel as a dynamic imaging sensor. The X-ray detection panel can detect visible light by converting X-rays into visible light through a scintillator.

[0008] Figure 1 Schematic layout diagram of an X-ray detection panel of a conventional dynamic X-ray detector.

[0009] See Figure 1 A conventional X-ray detection panel includes a plurality of pixels N, pixel N+1, pixel N+2, ..., wherein each Nth pixel includes a readout thin film transistor (TFT) and a photodiode.

[0010] In the thin film transistor, a readout terminal (ie, a drain) is connected to a readout IC through a readout pad, and a gate is connected to a gate IC through a gate pad.

[0011] The photodiode is connected to the bias terminal through a bias pad.

[0012] Figure 2 is a schematic diagram illustrating a switching operation of a readout thin film transistor in a conventional X-ray detection panel, and Figure 3 A schematic diagram showing a driving timing of a conventional X-ray detection panel.

[0013] First, see Figure 2 Conventional X-ray detection panels obtain image data through the sequential steps of global reset, window time, and readout. The readout TFT is turned on during the global reset, turned off during the window time, and turned on during the readout step.

[0014] See Figure 3 In this method, a global reset is performed simultaneously for a predetermined period of time on all lines, a window time is also performed simultaneously on all lines, and a readout step is performed sequentially for each line. This method causes a time delay in each line between the window time and the readout step, causing image lag and ghosting when performing dynamic X-ray imaging. Therefore, this method of driving conventional X-ray detectors is unsuitable for dynamic X-ray detectors that require high frame rates. Summary of the Invention

[0015] Embodiments of the present invention provide a dynamic X-ray detection panel capable of preventing a time delay in each line between a window time and readout, a dynamic X-ray detector including the dynamic X-ray detection panel, and a method of driving the X-ray detector.

[0016] In addition, embodiments of the present invention provide a dynamic X-ray detection panel suitable for acquiring high frame rate X-ray images, a dynamic X-ray detector including the dynamic X-ray detection panel, and a method for driving the X-ray detector.

[0017] According to one aspect of the present invention, a method for driving a dynamic X-ray detector is provided. The dynamic X-ray detector driving method is a method for driving a dynamic X-ray detector including an X-ray detection panel. The X-ray detection panel includes a plurality of pixels arranged in a matrix, wherein each pixel includes a readout thin-film transistor, a reset thin-film transistor, and a photodiode, and a line reset, window timing, and readout are performed for the plurality of pixels in each row.

[0018] In one embodiment, the start time of the window time of the subsequent row may be later than the start time of the window time of the previous row, and the readout of pixels in the subsequent row may be performed after the readout of pixels in the previous row is completed.

[0019] Furthermore, the completion of the readout of the previous row can coincide with the window time for the completion of the next row.

[0020] Furthermore, the reset time may be longer than the readout time, and an idle time may be defined after the readout time is completed. The idle time may correspond to the difference between the reset time and the readout time.

[0021] In one embodiment, the line reset of a subsequent row may be started after the line reset of a previous row is completed.

[0022] Furthermore, the reset time may be shorter than the readout time, and an idle time may be defined after the reset time is completed. The idle time may correspond to the difference between the reset time and the readout time.

[0023] In another embodiment, the line reset of a subsequent row may be performed before the line reset of a previous row is completed, and the line reset of the subsequent row may be completed within a predetermined period of time after the line reset of the previous row is completed.

[0024] In one embodiment, each of the reset time, the window time, and the readout time may be identically defined with respect to all rows of pixels in the detection panel.

[0025] In one embodiment, during online resetting, the reset thin film transistor of the corresponding row may be in the on state and the readout thin film transistor of the corresponding row may be in the off state; during the window time, the reset thin film transistor of the corresponding row may be in the off state and the readout thin film transistor of the corresponding row may be in the off state; and during reading, the reset thin film transistor of the corresponding row may be in the off state and the readout thin film transistor of the corresponding row may be in the on state.

[0026] In addition, the gate of the readout thin film transistor in each row of pixels may be commonly connected to a readout gate pad; the drain of the readout thin film transistor in each row of pixels may be respectively connected to different readout pads; the gate of the reset thin film transistor in each row of pixels may be commonly connected to a reset gate pad; the drain of the reset thin film transistor in multiple pixels may be commonly connected to the reset drain pad; and the photodiode in each of the pixels may be commonly connected to the source of the reset thin film transistor and the readout thin film transistor therein.

[0027] According to another aspect of the present invention, a dynamic X-ray detection panel may include: a plurality of pixels arranged in a matrix and each including a readout thin film transistor, a reset thin film transistor and a photodiode; a plurality of readout gate pads, each typically connected to the gate of the readout thin film transistor in a row of pixels; a readout pad, each typically connected to the drain of the readout thin film transistor in a row of pixels; a plurality of reset gate pads, each typically connected to the gate of the reset thin film transistor in each row of pixels; and at least one reset drain pad, typically connected to the drain of the reset thin film transistor in a plurality of pixels, wherein the photodiode in each of the pixels is typically connected to the source of the reset thin film transistor and the readout thin film transistor therein.

[0028] The dynamic X-ray detection panel may further comprise a bias pad typically connected to the anodes (positive terminals) of the photodiodes in the plurality of pixels.

[0029] The readout pads may be commonly connected to the readout thin film transistors in the pixels of each column.

[0030] The dynamic X-ray detection panel may include a plurality of reset drain pads each typically connected to the drain of the reset thin film transistor in the plurality of pixels, the plurality of reset drain pads being positioned at upper and lower positions and / or right and left positions in the detection panel.

[0031] According to another aspect of the present invention, there is provided a dynamic X-ray detector comprising the dynamic X-ray detection panel described above.

[0032] The dynamic X-ray detector may further include a readout gate IC connected to the readout gate pad; a readout IC connected to the readout pad; and a reset gate IC connected to the reset gate pad.

[0033] According to embodiments of the present invention, a dynamic X-ray detection panel and an X-ray detector including the same can prevent a time delay in each line between window time and readout. In addition, the method of driving the X-ray detector is suitable for acquiring high-frame-rate X-ray images. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic layout diagram of an X-ray detection panel of a conventional dynamic X-ray detector.

[0035] Figure 2 is a schematic diagram illustrating a switching operation of a readout thin film transistor in a conventional X-ray detection panel.

[0036] Figure 3 FIG. 1 is a schematic diagram showing a driving timing of a conventional X-ray detection panel.

[0037] Figure 4Schematic layout diagram of an X-ray detection panel of a dynamic X-ray detector according to an embodiment of the present invention.

[0038] Figure 5 is a schematic diagram illustrating a switching operation of a thin film transistor in an X-ray detection panel according to an embodiment of the present invention.

[0039] Figure 6 FIG. 1 is a schematic diagram illustrating a driving timing sequence of an X-ray detection panel according to an embodiment of the present invention.

[0040] Figure 7 FIG. 1 is a schematic diagram illustrating optional driving timings of an X-ray detection panel according to various embodiments of the present invention.

[0041] Explanation of Figure Numbers

[0042] N, N+1, N+2, ...: pixels;

[0043] Vbias: bias voltage;

[0044] Vds(rst): drain-source voltage;

[0045] Vg(ro), Vg(rst): gate voltage. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that the following embodiments are provided to enable those skilled in the art to fully disclose and thoroughly understand the present invention. Therefore, the present invention is not limited to the following embodiments and can be implemented in different ways. It should be noted that the drawings are not drawn to exact scale and the width, length, and thickness of the components may be exaggerated only for ease of description and clarity. It should be understood that when an element is referred to as being placed "above" or "on" another element, the element may be placed directly above or on the other element, or there may be intervening elements therebetween. Throughout this specification, identical components will be represented by the same reference numerals, and similar components will be represented by similar reference numerals.

[0047] Figure 4 The following is a schematic layout diagram of an X-ray detection panel for a dynamic X-ray detector according to one embodiment of the present invention. Here, the X-ray detection panel is adapted for indirect detection, detecting visible light converted by a scintillator. However, it should be understood that the present invention is not limited thereto and can also be applied to direct detection X-ray detection panels for directly detecting X-rays.

[0048] See Figure 4The X-ray detection panel includes a plurality of pixels N, pixel N+1, pixel N+2, ..., and each pixel (the Nth pixel) includes a readout thin-film transistor (readout TFT), a reset thin-film transistor (reset TFT), and a photodiode. Furthermore, the X-ray detection panel may include a readout pad, a readout gate pad, a reset gate pad, a reset drain pad, and a bias pad.

[0049] The plurality of pixels may be arranged in a matrix, but is not limited thereto. For example, the plurality of pixels may include pixels arranged in 5,000×5,000 columns and rows.

[0050] Each of the readout TFT and the reset TFT may be a switching device including amorphous silicon, an oxide of at least one of In—Ga—Zn—O, or polycrystalline silicon as a semiconductor layer. The photodiode may be a device including amorphous silicon, an oxide of at least one of In—Ga—Zn—O, polycrystalline silicon, or an organic compound as a photoelectric conversion layer.

[0051] First, for example, the connection structure of the readout TFT, the reset TFT, and the photodiode in the N-th pixel will be described.

[0052] A readout terminal of the readout TFT (ie, a drain of the readout TFT) is connected to the readout IC through a readout pad, and a gate of the readout TFT is connected to the readout gate IC through a readout gate pad.

[0053] The drain of the reset TFT is connected to the drain-source voltage terminal Vds(rst) through a reset drain pad, and the gate of the reset TFT is connected to the reset gate IC through a reset gate pad.

[0054] The photodiode is connected to the bias voltage terminal Vbias via a bias pad. The anode of the photodiode can be connected to the bias pad, and the cathode of the photodiode can be connected to the source of the readout TFT and the reset TFT. Alternatively, the cathode of the photodiode can be connected to the bias pad, and the anode of the photodiode can be connected to the source of the readout TFT and the reset TFT.

[0055] Each of the bias pad and the reset drain pad may be commonly connected to all multiple pixels N, pixel N+1, pixel N+2, ... That is, all multiple photodiodes in the detection panel may be commonly connected to one bias pad, and the drains of multiple reset TFTs may be commonly connected to one reset drain pad. In this embodiment, each of the bias pad and the reset drain pad is provided separately. Alternatively, the detection panel may have multiple bias pads and multiple reset drain pads. Each of the bias pads may be commonly connected to multiple photodiodes in the detection panel, and each of the reset drain pads may be commonly connected to the drains of multiple reset TFTs in the detection panel. Multiple reset drain pads may be positioned at upper and lower positions and / or right and left positions in the detection board. This arrangement of multiple reset drain pads can reduce the connection length between the reset drain pad and the pixel, thereby reducing the RC delay.

[0056] On the other hand, pixels arranged in the same row may be commonly connected to one readout gate pad and one reset gate pad, while pixels arranged in different rows may be connected to different readout gate pads and different reset gate pads. That is, the gates of the readout TFTs in pixels arranged in the same row may be commonly connected to one readout gate pad, while the gates of the readout TFTs in pixels arranged in different rows may be connected to different readout gate pads. Furthermore, the gates of the reset TFTs in pixels arranged in the same row may be commonly connected to one reset gate pad, while the gates of the reset TFTs in pixels arranged in different rows may be connected to different reset gate pads.

[0057] On the other hand, pixels arranged in the same column can be commonly connected to one readout pad, while pixels arranged in different columns can be connected to different readout pads. That is, the drains of the readout TFTs in pixels arranged in the same column are commonly connected to one readout pad, while the drains of the readout TFTs in pixels arranged in different columns are connected to different readout pads. Therefore, pixels arranged in one row are connected to different readout pads.

[0058] Through this connection arrangement of transistors and photodiodes in pixels arranged in a matrix, the detection panel allows easy reset and readout operations in each line (ie, in each row), thereby providing optimal image data for high frame rate X-ray images.

[0059] Figure 5 is a schematic diagram illustrating a switching operation of a thin film transistor in an X-ray detection panel according to an embodiment of the present invention.

[0060] See Figure 5 In this embodiment, in pixel N, pixel N+1, pixel N+2, . . . , line reset may be performed line by line, that is, in each row.

[0061] During an online reset, the reset TFT is turned on and the readout TFT is turned off. For example, a gate voltage Vg(rst) is applied to the gate of the reset TFT via the reset gate IC to turn on the reset TFT, and a gate voltage Vg(ro) is applied to the gate of the readout TFT via the readout gate IC to turn off the readout TFT. For example, during an online reset, the gate voltage Vg(rst) of the reset TFT may be in the range of 0V to 30V, the drain-source voltage may be in the range of 0V to 20V, or the drain may be floating. Alternatively, the gate voltage Vg(ro) of the readout TFT may be in the range of 0V to -30V, the drain-source voltage may be in the range of 0V to 20V, or the drain may be floating. Alternatively, a bias voltage Vbias may be applied to the photodiode. The bias voltage Vbias may be in the range of, for example, -10V to 10V.

[0062] With line reset, residual charge in pixels connected to the reset gate pad is removed via the reset TFT, thereby resetting the pixels. When a line reset for one line (row) is completed, a line reset for the next line can be performed. In this way, a reset operation can be performed for pixels in every line of the X-ray detection panel.

[0063] After the reset is performed, a window time is used to collect data generated by X-ray irradiation. In this embodiment, the term "window time" refers to the time during which the charge generated in the photodiode by X-ray irradiation is saturated. The window time can be arbitrarily set in consideration of the charge saturation time of the photodiode.

[0064] For the window time, both the reset TFT and the readout TFT are turned off. For example, a gate voltage Vg(rst) is applied to the gate of the reset TFT by the reset gate IC to turn off the reset TFT, and a gate voltage Vg(ro) is applied to the gate of the readout TFT by the readout gate IC to turn off the readout TFT. For example, for the window time, the gate voltage Vg(rst) of the reset TFT may be in the range of 0V to 30V, the drain-source voltage may be in the range of 0V to 20V, or the drain may be floating. In addition, the gate voltage Vg(ro) of the readout TFT may be in the range of 0V to -30V, the drain-source voltage may be in the range of 0V to 20V, or the drain may be floating. On the other hand, a bias voltage Vbias may be applied to the photodiode. The bias voltage Vbias may be in the range of, for example, -10V to 10V.

[0065] By irradiating the photodiode with X-rays, a photoelectric conversion occurs to generate charge therein. Since the readout TFT and the reset TFT are in the off state, the charge generated in the photodiode can be accumulated in the photodiode or in the source of the readout TFT.

[0066] In the readout step, the reset TFT is kept in an off state and the readout TFT is turned on. For example, a gate voltage Vg(rst) is applied to the gate of the reset TFT by the reset gate IC so that the reset TFT remains in an off state, and a gate voltage Vg(ro) is applied to the gate of the readout TFT by the readout gate IC to turn on the readout TFT. For example, in the readout step, the gate voltage Vg(rst) of the reset TFT may be in a range of 0V to -30V, the drain-source voltage may be in a range of 0V to 20V, or the drain may be floating. In addition, the gate voltage Vg(ro) of the readout TFT may be in a range of 0V to 30V, the drain-source voltage may be in a range of 0V to 20V, or the drain may be floating. On the other hand, a bias voltage Vbias may be applied to the photodiode. The bias voltage Vbias may be in a range of, for example, -10V to 10V.

[0067] In the readout step, the charge generated in the photodiode moves from the source electrode of the readout TFT to the drain electrode and is transferred to the readout IC through the readout pad. The readout IC can use the charge data to generate image data.

[0068] Line reset, window timing, and readout are performed sequentially, and data for a single line is processed through these steps. By sequentially processing the data for each line, a frame of data for all pixels is obtained. By repeatedly processing the data for each line, multiple frames of data are obtained, enabling the implementation of dynamic images.

[0069] Will refer to Figure 6 The method of performing line reset, window time, and readout for each line is described in more detail. Figure 6 FIG. 1 is a schematic diagram illustrating a driving timing sequence of an X-ray detection panel according to an embodiment of the present invention. Figure 6 Line reset, window time, and readout are plotted relative to the first row.

[0070] See Figure 6 , perform line reset, window time and readout for each line, as shown in Figure 5 As described above. For example, line reset, window timing, and readout are performed with respect to the first row. To reset the pixels in the first row, the reset TFTs in the pixels in the first row are turned on. Here, the reset TFTs in the pixels in other rows may be in an off state, but are not limited thereto. For example, the pixels in other rows may be reset together with the pixels in the first row.

[0071] A line reset is performed for the pixels in the first row to remove any charge remaining in the source electrodes of the photodiodes and readout TFTs, or any charge caused by parasitic capacitance. The line reset may be performed for a sufficient period of time to remove any remaining charge. For example, the line reset period may be set or experimentally determined, taking into account the materials and capacities of the readout TFTs, reset TFTs, and photodiodes.

[0072] After performing a line reset for the first row, the reset TFTs in the first row are turned off. Meanwhile, the readout TFTs in the first row remain off. Therefore, the charge generated in the photodiodes by X-ray irradiation accumulates in the photodiodes and the source electrodes of the readout TFTs. During the window period, the charge in the source electrodes of the readout TFTs can be saturated.

[0073] After the window time, the readout TFTs of the first row are turned on. Thus, the charges accumulated in the photodiodes and the sources of each of the readout TFTs in the first row are transferred to the readout IC through the drains of the readout TFTs and the readout pads.

[0074] After completing the readout of the first row, the readout of the second row can be performed, and after completing the readout of the second row, the readout of the third row can be performed. This process completes the readout of each row, thereby providing one frame of data. According to this embodiment, the completion of the readout of the immediately preceding row can coincide with the completion of the window time of the succeeding row. In addition, the start time of the window time of the preceding row can coincide with the start time of the reset time of the succeeding row.

[0075] In this embodiment, the timing can be set to allow for continuous readout, thereby achieving high frame rate dynamic imaging data while reducing the time required for a single frame. However, it should be understood that the present invention is not limited to this. For example, the line reset or window time for the second row can begin after the readout of the first row is completed.

[0076] According to this embodiment, windowing and readout are performed sequentially for each line, thereby eliminating any time delay between windowing and readout. Therefore, unlike conventional X-ray detection panels, the X-ray detection panel according to this embodiment enables high-frame-rate dynamic imaging without image lag or afterimages.

[0077] Figure 7 FIG. 1 is a schematic diagram illustrating optional driving timings of an X-ray detection panel according to various embodiments of the present invention.

[0078] During X-ray irradiation, each pixel accumulates data by disconnecting the reset TFT and readout TFT. That is, during the window time, charge accumulates in the photodiode and the source of the readout TFT. The window time is set to allow the charge therein to be substantially saturated and is typically longer than the reset time or the readout time. On the other hand, the reset time can be the same as or different from the readout time, and in either case, the drive timing can be adjusted.

[0079] See Figure 7 , timing 1 indicates the case where the reset time is the same as the readout time. When the reset time is the same as the readout time, the completion of the readout of the previous row can coincide with the start of the readout of the next row, as shown in the reference Figure 6 Alternatively, the completion of the readout of the previous row may coincide with the window time for completing the next row. Alternatively, the reset time for completing the previous row or the window time for starting the previous row may coincide with the reset time for starting the next row.

[0080] Timing 2 indicates the case where the reset time is longer than the readout time. Figure 6 Line reset, window timing, and readout are performed in the same manner as in the previous row, and the completion of readout of the previous row does not coincide with the window timing of the next row. To compensate for this, an idle time can be defined. The idle time can be defined as the time corresponding to the difference between the reset time and the readout time. During the idle time, the readout TFT can be disconnected.

[0081] Unlike sequence 2, sequence 3 indicates a situation where the reset time is shorter than the readout time. In this case, readout of the next row begins after the previous row has finished reading, and the start time of the previous row's window time does not coincide with the start time of the reset of the next row. To compensate for this, an idle time can be defined between the reset time and the window time. During this idle time, the reset TFT can be turned off.

[0082] According to this embodiment, even when the reset time does not coincide with the readout time, the idle time is positioned therebetween to optimize the timing drive of the detection panel.

[0083] While the reset of a subsequent row has been described as starting after the reset of the previous row has been completed, it should be understood that other implementations are possible. For example, the reset of all rows can be started simultaneously. Here, the completion time of the reset is different for each row, so that readout can be performed without time delay after the window time.

[0084] Although some embodiments have been described herein, it should be understood that these embodiments should not be interpreted as limiting the present invention in any way. It should be understood that those skilled in the art can make various modifications, changes and alterations without departing from the spirit and scope of the present invention.

Claims

1. A method for driving a dynamic X-ray detector, the dynamic X-ray detector comprising an X-ray detection panel, wherein line reset, window timing, and readout are performed row by row for each frame time with respect to a plurality of pixels in an effective image area, each of the plurality of pixels comprising a readout thin-film transistor, a reset thin-film transistor, and a photodiode. wherein each of the reset time, the window time, and the readout time is identically defined in each frame time with respect to the pixels of each row in the effective image area, The start of line reset of the latter row is later than the start of line reset of the previous row, In each row, a time interval between readout and line reset after the readout is longer than a window time between line reset and readout after the line reset.

2. The method for driving a dynamic X-ray detector according to claim 1 , wherein a start of a window time for a subsequent row is later than a start of a window time for a previous row, and the reading of the pixels in the subsequent row is performed before the reading of the pixels in the previous row is completed. 3 . The method for driving a dynamic X-ray detector according to claim 2 , wherein completion of readout of the previous row coincides with completion of the window time of the subsequent row.

4. The method of driving a dynamic X-ray detector according to claim 3, wherein the reset time is longer than the readout time, and an idle time corresponding to the difference between the reset time and the readout time is defined after the readout time is completed. 5 . The method of driving a dynamic X-ray detector according to claim 2 , wherein the line reset of the subsequent row is started after the line reset of the previous row is completed. 6 . The method of driving a dynamic X-ray detector according to claim 5 , wherein a reset time is shorter than a readout time, and an idle time corresponding to a difference between the reset time and the readout time is defined after the reset time is completed.

7. The method for driving a dynamic X-ray detector according to claim 2, wherein the line reset of the subsequent row is performed before the line reset of the previous row is completed, and the line reset of the subsequent row is completed within a predetermined time period after the line reset of the previous row is completed.

8. The method for driving a dynamic X-ray detector according to claim 1, wherein: During line resetting, the reset thin film transistors of the corresponding row are in an on state, and the readout thin film transistors of the corresponding row are in an off state; During the window time, the reset thin film transistor of the corresponding row is in an off state, and the readout thin film transistor of the corresponding row is in an off state; and During readout, the reset thin film transistors of the corresponding row are in an off state, and the readout thin film transistors of the corresponding row are in an on state.

9. The method for driving a dynamic X-ray detector according to claim 8, wherein: The gates of the readout thin film transistors in the pixels of each row are typically connected to a readout gate pad; The drains of the readout thin film transistors in the pixels of each row are respectively connected to different readout pads; The gates of the reset thin film transistors in the pixels of each row are generally connected to a reset gate pad; The drains of the reset thin film transistors in the plurality of pixels are commonly connected to a reset drain pad; and The photodiode in each of the pixels is commonly connected to sources of the readout thin film transistor and the reset thin film transistor in each of the pixels.

Images