Photosensitive unit array driving circuit and photosensitive flat panel detector

Abstract

The embodiment of the present application relates to a photosensitive unit array driving circuit and a photosensitive flat panel detector, the circuit comprising: a photosensitive unit array, N first scan lines, N second scan lines, M data lines, and a bias output unit; each photosensitive unit comprises a photosensitive subunit and a current release subunit; each row of photosensitive units corresponds to a first scan line and a second scan line, and the first scan line and the second scan line are respectively connected to the photosensitive subunit and the current release subunit included in the photosensitive unit in the corresponding row; the first scan line is used to output a scan drive signal to the corresponding photosensitive subunit; the second scan line is used to output a control signal to the connected current release subunit after the scan drive signal is turned off, so that the current release subunit releases the leakage current. The embodiment of the present application realizes that after each row of the photosensitive unit array is scanned, the residual leakage current in the photosensitive unit is released, thereby effectively reducing the influence of the leakage current on the imaging quality.

Description

Technical Field

[0001] The present application relates to the field of photoelectric detection technology, and in particular to a photosensitive unit array driving circuit and a photosensitive flat panel detector. Background Art

[0002] Compared with the traditional film-type photosensitive system, the current digital medical imaging X-ray flat panel detector has the advantages of low radiation dose, fast electronic imaging, easy image inspection, reproduction, acquisition and transmission analysis, etc., with the advantages of low cost, high yield and high profit. Digital X-ray flat panel detectors are widely used in aerospace, medical, non-destructive testing and other industrial fields. Its products are highly favored for their excellent quality and convenient data transmission. With the development of amorphous silicon technology and large-scale integrated circuits in the liquid crystal display panel industry, the research on digital X-ray flat panel detection technology has become more and more in-depth.

[0003] The working principle of the X-ray flat-panel detector is that when X-rays shine on a person or object, the photosensitive element converts the X-rays of different intensities that are attenuated after passing through the detected object into visible light. The visible light is irradiated on the TFT panel, and the visible light is converted into an electrical signal through the conduction of the photodiode in the TFT panel. After receiving the electrical signal, the data-driven processor performs calculation processing and finally displays the image.

[0004] The structure of the traditional X-ray flat-panel image detector is as follows: Figure 1 As shown, it includes longitudinal data lines (Data Line) and transverse scanning lines (Gate Line). The photosensitive unit array is opened row by row under the drive of the scanning (Gate) signal. The negative voltage connected to one end of the switching element in the photosensitive unit will leak to the other end of the switching element. The magnitude of the induced current depends on the strength of the conduction degree of the photosensitive diode under the action of X-rays. When the Gate line is opened row by row, the RO IC (Readout IC) will receive leakage charges of different intensities and transmit differential signals to the driving processor. However, due to the leakage of the photosensitive diode inside the photosensitive unit, the uniformity of the grayscale image is poor and the image quality generated is poor. Therefore, how to eliminate the influence of the leakage current inside the photosensitive unit is a problem that needs to be solved at present. Summary of the invention

[0005] In view of this, in order to solve some or all of the above-mentioned technical problems, the embodiments of the present application provide a photosensitive unit array driving circuit, a display panel and a display device.

[0006] In a first aspect, an embodiment of the present application provides a photosensitive unit array driving circuit, which includes: a photosensitive unit array, N first scan lines, N second scan lines, M data lines, and a bias output unit; each photosensitive unit in the photosensitive unit array includes a photosensitive sub-unit and a current release sub-unit; the input end of each photosensitive sub-unit in the photosensitive unit array is connected to the bias output unit, and the output end is connected to the corresponding data line; the input end of each current release sub-unit in the photosensitive unit array is connected to the corresponding photosensitive sub-unit, and the output end is connected to the current release end; each row in the photosensitive unit array corresponds to a first scan line and a second scan line, the first scan line is connected to the photosensitive sub-unit included in the photosensitive unit in the corresponding row, and the second scan line is connected to the current release sub-unit included in the photosensitive unit in the corresponding row; the first scan line is used to output a scan drive signal to the corresponding photosensitive sub-unit; the second scan line is used to output a control signal to the connected current release sub-unit after the scan drive signal is turned off, so that the current release sub-unit releases the leakage current.

[0007] In one possible embodiment, the photosensitive subunit includes a first switching element and a photosensitive element, and the current release subunit includes a second switching element; one end of the photosensitive element is connected to the bias output unit, and the other end is connected to the first switching element; the control end of the first switching element is connected to the corresponding first scanning line, and the two signal transmission ends are respectively connected to the corresponding data line and the photosensitive element; the control end of the second switching element is connected to the corresponding second scanning line, and the two signal transmission ends are respectively connected to the photosensitive element and the current release end.

[0008] In a possible implementation, the current release subunit further includes a capacitor, one end of the capacitor is connected to the signal output end of the photosensitive element, and the other end of the capacitor is connected to the current release end.

[0009] In a possible embodiment, the first switching element and the second switching element are thin film transistors TFT, the control ends of the first switching element and the second switching element are gates of the thin film transistor TFT, the two signal transmission ends of the first switching element are respectively connected to the corresponding data line and the photosensitive element, and the two signal transmission ends of the second switching element are respectively connected to the corresponding photosensitive element and the current release end.

[0010] In a possible implementation manner, the photosensitive element is a photosensitive diode, an anode of the photosensitive diode is connected to the bias output unit, and a cathode of the photosensitive diode is connected to the first switch element and the second switch element.

[0011] In one possible embodiment, the circuit also includes a feedback compensation module and M feedback lines, each feedback line corresponds to a column of the photosensitive unit array, each feedback line is connected to the output end of the photosensitive element included in the corresponding column and to the input end of the feedback compensation module, and M data lines are connected to the output end of the feedback compensation module; the feedback compensation module is used to output a compensation voltage to the M data lines to offset the leakage current of the photosensitive elements in the photosensitive unit array when not illuminated.

[0012] In one possible embodiment, the feedback compensation module includes a current detection subunit and a current compensation subunit, the input end of the current detection subunit is connected to M feedback lines, the output end of the current detection subunit is connected to the input end of the current compensation subunit, and the output end of the current compensation subunit is connected to M data lines; the current detection subunit is used to convert the current signal on the M feedback lines into a voltage signal; the current compensation subunit is used to adjust the voltage signal and output a compensation current to the M data lines based on the adjusted voltage signal.

[0013] In one possible implementation, the current detection subunit includes a current detection resistor and an operational amplifier circuit, one end of the current detection resistor is connected to M feedback lines, and the other end is connected to the ground end; the two input ends of the operational amplifier circuit are respectively connected to the two ends of the current detection resistor.

[0014] In one possible implementation, the current compensation subunit includes a filter circuit and a load resistor; the input end of the filter circuit is connected to the output end of the current detection subunit, and the output end of the filter circuit is connected to one end of the load resistor; the other end of the load resistor is connected to M data lines.

[0015] In a second aspect, an embodiment of the present application provides a photosensitive flat panel detector, which includes: a photosensitive unit array driving circuit, and also includes a timing controller, a scanning driving module, a signal receiving module, a signal processing module and an image generating module; the timing controller is connected to the scanning driving module, the scanning driving module is connected to N first scanning lines and N second scanning lines in the photosensitive unit array driving circuit, the signal receiving module is connected to M data lines in the photosensitive unit array driving circuit, the signal processing module is connected to the signal receiving module, and the image generating module is connected to the signal processing module; the timing controller is used to generate a scanning timing instruction, and the scanning timing instruction is sent to the receiving module. Sent to the scanning drive module; the scanning drive module is used to output a scanning drive signal to the current first scanning line under the control of the scanning timing instruction, and after the scanning drive signal is turned off, output a control signal to the current second scanning line, so that the current release sub-unit in the photosensitive unit array driving circuit releases the leakage current; the signal receiving module is used to receive the induced current output by M data lines, generate a signal to be processed based on the induced current, and send the signal to be processed to the signal processing module; the signal processing module is used to process the signal to be processed to obtain processed data for generating an image; the image generation module is used to generate a photosensitive image according to the processed data.

[0016] The photosensitive unit array driving circuit and the photosensitive flat panel detector provided in the embodiment of the present application are provided with a photosensitive subunit and a current release subunit in each photosensitive unit included in the photosensitive unit array, and two scanning lines are provided for each row of the photosensitive units, one scanning line is used to output a scanning driving signal to the photosensitive subunit, and the other scanning line is used to output a control signal to the current release subunit after the output of the scanning driving signal is completed, so that the leakage current in the row of photosensitive subunits that has been scanned is released through the current release subunit. The embodiment of the present application realizes that after each row of the photosensitive unit array is scanned, the residual leakage current in the row of photosensitive units that has been scanned is released, thereby effectively reducing the influence of the leakage current on the imaging quality, improving the quality of the sensing signal, and improving the grayscale contrast, so that the generated image has better uniformity and higher definition. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0020] Figure 1 It is a structural schematic diagram of an existing photosensitive unit array driving circuit;

[0021] Figure 2 A schematic diagram of the structure of a photosensitive unit array driving circuit provided in an embodiment of the present application;

[0022] Figure 3 A timing diagram of signals on a first scan line and a second scan line provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the structure of a photosensitive unit provided in an embodiment of the present application;

[0024] Figure 5 Another schematic diagram of the structure of the photosensitive unit provided in the embodiment of the present application;

[0025] Figure 6 A schematic diagram of the structure of another photosensitive unit array driving circuit provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of the structure of another photosensitive unit array driving circuit provided in an embodiment of the present application;

[0027] Figure 8 A schematic diagram of the structure of a feedback compensation module provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of the structure of another feedback compensation module provided in an embodiment of the present application;

[0029] Fig.10 This is a schematic diagram of the structure of a photosensitive flat panel detector provided in an embodiment of the present application.

[0030] Reference numerals:

[0031] 200-photosensitive unit array driving circuit; 201-photosensitive unit array; 2011-photosensitive sub-unit; 2012-current release sub-unit; 202-first scanning line; 203-second scanning line; 204-data line; 205-bias output unit; 206-feedback compensation module; 2061-current detection sub-unit; 20611-operational amplifier circuit; 2062-current compensation sub-unit; 20621-filtering circuit; 207-feedback line; 1000-photosensitive flat panel detector; 1001-timing controller; 1002-scanning drive module; 1003-signal receiving module; 1004-signal processing module; 1005-image generation module. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the numerical expressions and the numerical values ​​described in these embodiments do not limit the scope of the present application.

[0033] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present application are only used to distinguish between different steps, devices, modules and other objects, and do not represent any specific technical meanings, nor do they indicate the logical order between them.

[0034] It should also be understood that in this embodiment, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0035] It should also be understood that any component, data or structure mentioned in the embodiments of the present application can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0036] In addition, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0037] It should also be understood that the description of the various embodiments in this application focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0039] Technologies, circuits, and devices known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the above-mentioned technologies, circuits, and devices should be considered as part of the specification.

[0040] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0041] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. To facilitate the understanding of the embodiments of the present application, the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0042] Figure 2 A schematic diagram of the structure of a photosensitive unit array driving circuit provided in an embodiment of the present application, which is generally used in an X-ray flat panel detector, and specifically includes: a photosensitive unit array 201, N first scan lines 202, N second scan lines 203, M data lines 204 (including data line 1-data line M), and a bias output unit 205. Wherein, N and M are integers greater than 1. Generally, N can be the number of rows of the photosensitive unit array, and M is the number of columns of the photosensitive unit array. Each data line corresponds to a column of photosensitive units, and a row of photosensitive units corresponds to a first scan line and a second scan line.

[0043] In this embodiment, each photosensitive unit in the photosensitive unit array 201 includes a photosensitive subunit 2011 (P in the figure represents the photosensitive subunit 2011) and a current release subunit 2012 (L in the figure represents the current release subunit 2012). Each photosensitive subunit 2011 can sense a specific type of light (such as X-rays), that is, the light intensity is related to the magnitude of the current flowing through the photosensitive subunit 2011, thereby realizing the detection of objects. The current release subunit 2012 can be connected to the photosensitive subunit 2011 to release the leakage current of the connected photosensitive subunit 2011 to the ground terminal (GND).

[0044] In this embodiment, the input end of each photosensitive subunit 2011 in the photosensitive subunit array 201 is connected to the bias output unit, and the output end is connected to the corresponding data line. The bias output unit is connected to each photosensitive subunit 2011 in the photosensitive subunit array 201, and is used to input a bias voltage to each photosensitive subunit 2011. Figure 2As shown, the bias output unit inputs a bias signal Bias to each photosensitive subunit 2011. When a photosensitive subunit 2011 is driven by a scan drive signal output from a connected scan line, the photosensitive subunit 2011 can output a current to a connected data line under the drive of the bias signal Bias according to the received light intensity, and the corresponding grayscale can be presented on the corresponding pixel according to the magnitude of the current, thereby realizing photosensitivity and imaging.

[0045] In this embodiment, if Figure 2 As shown, the input end of each current release subunit 2012 in the photosensitive unit array 201 is connected to the corresponding photosensitive subunit 2011, and the output end is connected to the current release end.

[0046] Among them, the current release terminal is usually the ground terminal (GND).

[0047] In this embodiment, if Figure 2 As shown, each row in the photosensitive unit array 201 corresponds to a first scan line and a second scan line, and the first scan line and the second scan line are respectively connected to the photosensitive sub-unit 2011 and the current release sub-unit 2012 included in the photosensitive unit in the corresponding row.

[0048] like Figure 2 As shown, for the first row of photosensitive unit array 201, the corresponding first scan line is scan line 1, and the corresponding second scan line is scan line 1'. Similarly, the first scan line corresponding to the Nth row is scan line N, and the corresponding second scan line is scan line N'.

[0049] In this embodiment, the first scanning line is used to output a scanning driving signal to the corresponding photosensitive subunit 2011. Driven by the scanning driving signal, the photosensitive subunit 2011 is connected to the bias output unit. During the connection period, under the action of the bias output unit, a photosensitive current is generated and the photosensitive current is output to the connected data line. The data line outputs the photosensitive current to an external signal processing device, and the signal processing device converts the photosensitive current into a pixel grayscale, thereby obtaining a photosensitive image.

[0050] In this embodiment, the second scan line is used to output a control signal to the connected current release subunit 2012 after the scan drive signal is turned off, so that the current release subunit 2012 releases the leakage current.

[0051] The control signal can control the conduction state of the current release subunit 2012. After the effective photosensing time of the photosensitive subunit 2011 ends, the second scanning line outputs a control signal to turn on the current release subunit 2012 and release the leakage current to GND.

[0052] like Figure 3As shown, it shows the timing diagram corresponding to the first scan line and the second scan line corresponding to each row of the photosensitive unit array 201. Among them, CKn (n=1,2,3...N) is the scan timing signal of the nth row, and the scan drive module can output the scan drive signal to the first scan line of the nth row according to the signal, and CKn' is the control timing signal of the nth row, and the scan drive module can output the control signal to the second scan line according to the signal. Figure 3 It can be seen that when CK1 outputs a high level, the corresponding photosensitive subunit 2011 starts to sense light, and after a period of time, the effective photosensitive current is transmitted to the corresponding data line. At this time, CK1' can be set to a high level, so that the corresponding current release subunit 2012 releases the leakage current of the photosensitive subunit 2011 to GND. After CK1 is at a low level, the first row scan ends, and at this time CK1' continues to maintain a high level to fully release the leakage current until CK1' is set to a low level. According to this rule, the photosensitive unit array 201 is scanned line by line.

[0053] The photosensitive unit array driving circuit provided in the embodiment of the present application is provided with a photosensitive subunit and a current release subunit in each photosensitive unit included in the photosensitive unit array, and two scanning lines are provided for each row of the photosensitive units, one scanning line is used to output a scanning driving signal to the photosensitive subunit, and the other scanning line is used to output a control signal to the current release subunit after the output of the scanning driving signal is completed, so that the leakage current in the row of photosensitive subunits that has been scanned is released through the current release subunit. The embodiment of the present application realizes that after each row of scanning of the photosensitive unit array is completed, the residual leakage current in the row of photosensitive units that has been scanned is released, thereby effectively reducing the influence of the leakage current on the imaging quality, improving the quality of the sensing signal, and improving the grayscale contrast, so that the uniformity of the generated image is better and the clarity is higher.

[0054] In some optional implementations of this embodiment, such as Figure 4 As shown, the photosensitive subunit includes a first switching element and a photosensitive element, and the current release subunit includes a second switching element.

[0055] Figure 4 The schematic diagram of the structure of a row of photosensitive units is shown, wherein K1 is a first switch element, K2 is a second switch element, and PD is a photosensitive element. One end of the photosensitive element is connected to the bias output unit, and the other end is connected to the first switch element.

[0056] The control end of the first switch element is connected to the corresponding first scan line, and the two signal transmission ends are connected to the corresponding data line and the photosensitive element respectively.

[0057] The control end of the second switch element is connected to the corresponding second scanning line, and the two signal transmission ends are connected to the photosensitive element and the current release end respectively.

[0058] The first switch element and the second switch element may be TFT (Thin Film Transistor) elements, or MOS tubes, triodes, etc. As long as the controlled switch function can be realized, it is within the scope of this embodiment. The photosensitive element is used to sense the intensity of the currently irradiated light. Usually, different light intensities can cause corresponding changes in the resistance of the photosensitive element, thereby outputting a corresponding amount of current through the data line.

[0059] The control ends of the first switch element and the second switch element receive signals on the first scan line and the second scan line. Under the control of the received signals, the two signal transmission ends (such as the source and drain of the TFT) are turned on, thereby transmitting the signals to the data line and GND respectively.

[0060] This embodiment achieves effective control over the photosensing process of the photosensitive element and improves photosensitivity accuracy by setting a switching element and a photosensitive element in the photosensitive subunit. A second switching element is set in the current release subunit to effectively release the leakage current of the photosensitive element under the control of a control signal. The implementation method of the circuit is simple and effective, and can improve circuit manufacturing efficiency while improving imaging quality.

[0061] In some optional implementations of this embodiment, such as Figure 5 As shown, the current release subunit further includes a capacitor C, one end of which is connected to the signal output end of the photosensitive element, and the other end of which is connected to the current release end.

[0062] like Figure 5 As shown, the signal output end of the photosensitive element is one end connected to the first switch element, and the other end of the capacitor is connected to GND.

[0063] In this embodiment, by setting a capacitor, the voltage level on the photosensitive element can be maintained, which helps to improve the stability of the photosensitive current and improve the imaging quality.

[0064] In some optional implementations of the present embodiment, the first switching element and the second switching element are thin film transistors TFT, the control ends of the first switching element and the second switching element are gates of the thin film transistor TFT, the two signal transmission ends of the first switching element are respectively connected to the corresponding data line and the photosensitive element, and the two signal transmission ends of the second switching element are respectively connected to the corresponding photosensitive element and the current release end.

[0065] like Figure 6As shown, each photosensitive sub-unit includes a TFT1. When the first scan line connected to TFT1 outputs a scan drive signal, the TFT1 is turned on, and charge flows between the bias output unit and the photosensitive unit and the data line. Each current release sub-unit includes a TFT2. When the second scan line connected to TFT2 outputs a control signal, the TFT2 is turned on, and the leakage current of the photosensitive unit is released to GND.

[0066] It should be understood that Figure 6 The current release subunit shown includes a capacitor C, namely Figure 6 This embodiment is different from the above Figure 5 Combinations of corresponding embodiments. In some embodiments, Figure 6 The current release subunit in may also not include the capacitor C.

[0067] This embodiment uses TFT as a switching element to achieve a smaller volume and thickness of the switching unit, which helps to improve the light transmittance of the photosensitive unit array and improve the imaging quality.

[0068] In some optional implementations of this embodiment, the photosensitive element is a photosensitive diode, an anode of the photosensitive diode is connected to the bias output unit, and a cathode of the photosensitive diode is connected to the first switch element and the second switch element.

[0069] like Figure 6 As shown, each photosensitive subunit includes a TFT1 and a photosensitive diode PD. When the scan line connected to the TFT1 outputs a scan drive signal, the TFT1 is turned on, and charge flow occurs between the bias output unit and the PD and the data line.

[0070] This embodiment uses a photodiode as a photosensitive element to achieve accurate sensing of the projected light, which helps to improve the imaging quality.

[0071] In some optional implementations of this embodiment, such as Figure 7 As shown, the circuit also includes a feedback compensation module 206 and M feedback lines 207 (including feedback line 1-feedback line M), each feedback line corresponds to a column of the photosensitive unit array 201, each feedback line is connected to the output end of the photosensitive element included in the corresponding column, and is connected to the input end of the feedback compensation module, and M data lines 204 are connected to the output end of the feedback compensation module.

[0072] It should be noted that Figure 7 The other parts except the feedback compensation module and the feedback line are merely exemplary and do not constitute the scope of this embodiment. Figure 7 The connection method of the photosensitive element, the first switch element, and the second switch element in Figure 4 Same as shown.

[0073] The feedback compensation module is used to output a compensation voltage to the M data lines 204 to offset the leakage current of the photosensitive elements in the photosensitive unit array 201 when there is no light.

[0074] Specifically, under the condition of no light, that is, under the condition of dark state, the current (or voltage) on the data line should be 0, and the image generated at this time should be a pure black screen. However, due to the leakage current of the photosensitive element, the data line still has a certain current or voltage in the dark state, and the picture shows a difference in brightness. Therefore, in order to eliminate the influence of leakage current, this embodiment sets a feedback compensation module.

[0075] The feedback compensation module can detect the leakage current on each data line in the dark state, and output an opposite compensation current to the data line according to the leakage current, so that the current on the data line in the dark state is 0. For example, a current detection circuit can be set in the feedback compensation module to detect the sum of the leakage current on each feedback line. A current source is set in the feedback compensation module, and the current direction of the current source is opposite to the current direction on the data line, so that the sum of the current on the data line is 0.

[0076] Generally, the magnitude of the compensation current output by the feedback compensation module can be determined by calibration in a dark state, that is, in a dark state, the magnitude of the compensation current is adjusted so that the generated image is an ideal pure black picture.

[0077] This embodiment collects the leakage current of the photosensitive element under dark conditions by setting a feedback compensation module, thereby compensating for the leakage current under dark conditions, thereby eliminating the difference between the two banks in the generated image and further improving the imaging quality.

[0078] In some optional implementations of this embodiment, such as Figure 8 As shown, the feedback compensation module 206 includes a current detection subunit 2061 and a current compensation subunit 2062, the input end of the current detection subunit is connected to M feedback lines, the output end of the current detection subunit is connected to the input end of the current compensation subunit, and the output end of the current compensation subunit is connected to M data lines 204.

[0079] The current detection subunit is used to convert the current signals on the M feedback lines into voltage signals.

[0080] Specifically, the current detection subunit can use a current-voltage conversion circuit to achieve signal conversion. The magnitude of the converted voltage signal can reflect the magnitude of the current on the feedback line.

[0081] The current compensation subunit is used to adjust the voltage signal, and output a compensation current to the M data lines 204 based on the adjusted voltage signal.

[0082] Specifically, the current compensation subunit can amplify or reduce the received voltage signal, and output an adjusted compensation current through a load resistor. The compensation current is opposite to the current on the data line, so that the current on the data line can be 0 under dark conditions.

[0083] This embodiment sets a current detection subunit and a current compensation subunit in the feedback compensation module to adjust the size of the compensation current in a targeted manner according to the collected leakage current, so that the compensation current can accurately compensate for the leakage current generated by the photosensitive element under dark conditions, thereby improving the imaging quality.

[0084] In some optional implementations of this embodiment, such as Fig. 9 As shown, the current detection subunit includes a current detection resistor Rs and an operational amplifier circuit 20611, one end of the current detection resistor is connected to M feedback lines, and the other end is connected to the ground end. The two input ends of the operational amplifier circuit are respectively connected to the two ends of the current detection resistor.

[0085] like Fig. 9 As shown, the voltage across the current detection resistor is proportional to the total current on the received feedback lines. The operational amplifier OP1 and the peripheral resistors (including R1, R2, R3, R4) form a differential amplifier circuit to differentially amplify the voltage across the current detection resistor and output a voltage signal V1.

[0086] This embodiment configures a current detection subunit by providing a current detection resistor and an operational amplifier circuit, which can realize accurate detection and conversion of the current on the feedback line. The output voltage signal can accurately reflect the magnitude of the leakage current, thereby improving the accuracy of current compensation.

[0087] In some optional implementations of this embodiment, such as Fig. 9 As shown, the current compensation subunit includes a filter circuit 20621 and a load resistor R7. The input end of the filter circuit is connected to the output end of the current detection subunit, and the output end of the filter circuit is connected to one end of the load resistor. The other end of the load resistor is connected to M data lines 204.

[0088] like Fig. 9 As shown, the filter circuit includes an operational amplifier OP2, capacitors C1, C2 and resistors R5, R6. The filter circuit constitutes a first-order RC filter circuit, which can filter out high-frequency noise in the voltage signal V1. The output voltage signal V2 is applied to the load resistor, and a compensation current can be output to the data line.

[0089] The resistance value of the load resistor can be determined by calibration under dark conditions. Optionally, the load resistor can be an adjustable resistor, so that the magnitude of the compensation current output to the data line can be flexibly adjusted.

[0090] This embodiment achieves filtering of the voltage signal by setting a filter circuit and a load resistor in the current compensation subunit, thereby obtaining a stable voltage signal and outputting a stable current through the load resistor, thereby achieving stable compensation for the leakage current on the data line and further improving the imaging quality.

[0091] Fig.10 A schematic diagram of the structure of a photosensitive flat panel detector 1000 provided in an embodiment of the present application is shown in FIG. Fig.10 As shown, the photosensitive flat panel detector 1000 specifically includes: a photosensitive unit array driving circuit 200, a timing controller 1001, a scanning driving module 1002, a signal receiving module 1003, a signal processing module 1004 and an image generating module 1005. The photosensitive unit array driving circuit 200 is the photosensitive unit array driving circuit 200 described in the above embodiments.

[0092] The photosensitive flat panel detector in this embodiment can sense different types of light based on different types of photosensitive unit arrays. For example, when the photosensitive unit includes an X-ray photodiode, it can sense X-rays and generate an X-ray sensing image.

[0093] like Fig.10 As shown, the timing controller 1001 is connected to the scanning driving module 1002, the scanning driving module 1002 is connected to N first scanning lines and N second scanning lines in the photosensitive unit array driving circuit 200, the signal receiving module 1003 is connected to M data lines in the photosensitive unit array driving circuit 200, the signal processing module 1004 is connected to the signal receiving module 1003, and the image generating module 1005 is connected to the signal processing module 1004.

[0094] In this embodiment, the timing controller 1001 is used to generate a scan timing instruction and send the scan timing instruction to the scan driving module 1002 .

[0095] The timing controller 1001 may be an electronic device with logic processing capability, such as MCU, DSP, etc. The scanning timing instruction is as described above. Figure 3 Each drive unit in the scan drive module 1002 outputs corresponding scan drive signals and control signals to the connected photosensitive units according to the CKn and CKn' signals, so that the photosensitive units sense light and output sensed current, and release the leakage current after the light sensing is completed.

[0096] In this embodiment, the scanning drive module 1002 is used to output a scanning drive signal to the current first scanning line under the control of the scanning timing instruction, and after the scanning drive signal is turned off, output a control signal to the current second scanning line so that the current release subunit in the photosensitive unit array driving circuit 200 releases the leakage current.

[0097] In this embodiment, the signal receiving module 1003 is used to receive the induced currents output by the M data lines, generate a signal to be processed based on the induced currents, and send the signal to be processed to the signal processing module 1004 .

[0098] Among them, the above-mentioned signal receiving module 1003 can be a chip or circuit with signal processing capability. For example, the signal receiving module 1003 can include a RO IC (Read Out Integrated Circuit) and a driving circuit. The RO IC can collect the induced current and transmit the differential signal to the driving circuit. The driving circuit generates a signal to be processed based on the differential signal.

[0099] In this embodiment, the signal processing module 1004 is used to process the signal to be processed to obtain processed data for generating an image.

[0100] The signal processing module 1004 may be any electronic device with signal processing capability, such as FPGA, DSP, etc. The signal processing module 1004 may process the signal to be processed according to a preset processing algorithm (such as filtering, numerical conversion, etc.) to obtain processed data.

[0101] The image generation module 1005 is used to generate a photosensitive image according to the processed data.

[0102] The image generation module 1005 may be a separate electronic device with image processing capabilities, or may be integrated in the above-mentioned signal processing module 1004. The image generation module 1005 may execute an image processing algorithm to convert the received processed data into a photosensitive image. The photosensitive image may be sent by the image generation module 1005 to a display for display, or to a remote device for display.

[0103] The photosensitive flat-panel detector provided in this embodiment uses the photosensitive unit array driving circuit described in the above embodiments to release the residual leakage current in a row of photosensitive units at the end of the current scan after each row of the photosensitive unit array is scanned, thereby effectively reducing the impact of the leakage current on the imaging quality, improving the quality of the sensing signal, and enhancing the grayscale contrast, so that the generated photosensitive image has better uniformity and higher clarity.

[0104] The professionals should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different circuits to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0105] The steps of the circuits or algorithms described in conjunction with the embodiments disclosed herein may be implemented using hardware, software modules executed by a processor, or a combination of the two. The software modules may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0106] It should be understood that the terms used in the text are only for the purpose of describing specific example embodiments, and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used in the text may also be represented to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The steps, processes, and operations described in the text are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0107] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A photosensitive unit array driving circuit, characterized in that: The circuit comprises: a photosensitive unit array, N first scanning lines, N second scanning lines, M data lines, and a bias output unit; each photosensitive unit in the photosensitive unit array comprises a photosensitive subunit and a current release subunit; The input end of each photosensitive sub-unit in the photosensitive unit array is connected to the bias output unit, and the output end is connected to the corresponding data line; The input end of each current release subunit in the photosensitive unit array is connected to the corresponding photosensitive subunit, and the output end is connected to the current release end; Each row in the photosensitive unit array corresponds to a first scan line and a second scan line, the first scan line is connected to the photosensitive sub-unit included in the photosensitive unit in the corresponding row, and the second scan line is connected to the current release sub-unit included in the photosensitive unit in the corresponding row; The N first scanning lines are used to sequentially output scanning drive signals to the photosensitive sub-units of the corresponding rows; Each of the N second scan lines is used to output a control signal to the connected current release subunit after the scan drive signal corresponding to the row is turned off, so that the current release subunit of the row releases the leakage current.

2. The circuit according to claim 1, characterized in that The photosensitive subunit includes a first switch element and a photosensitive element, and the current release subunit includes a second switch element; One end of the photosensitive element is connected to the bias output unit, and the other end is connected to the first switch element; The control end of the first switch element is connected to the corresponding first scan line, and the two signal transmission ends are connected to the corresponding data line and the photosensitive element respectively; The control end of the second switch element is connected to the corresponding second scan line, and the two signal transmission ends are connected to the photosensitive element and the current release end respectively.

3. The circuit according to claim 2, characterized in that The current release subunit further includes a capacitor, one end of which is connected to the signal output end of the photosensitive element, and the other end of which is connected to the current release end.

4. The circuit according to claim 2, characterized in that The first switching element and the second switching element are thin film transistors TFT, the control ends of the first switching element and the second switching element are gates of the thin film transistors TFT, the two signal transmission ends of the first switching element are respectively connected to the corresponding data line and the photosensitive element, and the two signal transmission ends of the second switching element are respectively connected to the corresponding photosensitive element and the current release end.

5. The circuit according to claim 2, characterized in that The photosensitive element is a photosensitive diode, an anode of the photosensitive diode is connected to the bias output unit, and a cathode of the photosensitive diode is connected to the first switch element and the second switch element.

6. The circuit according to claim 2, characterized in that The circuit further includes a feedback compensation module and M feedback lines, each feedback line corresponds to a column of the photosensitive unit array, each feedback line is connected to the output end of the photosensitive element included in the corresponding column, and is connected to the input end of the feedback compensation module, and the M data lines are connected to the output end of the feedback compensation module; The feedback compensation module is used to output a compensation voltage to the M data lines to offset the leakage current of the photosensitive elements in the photosensitive unit array under the condition of no light.

7. The circuit according to claim 6, characterized in that The feedback compensation module comprises a current detection subunit and a current compensation subunit, wherein the input end of the current detection subunit is connected to the M feedback lines, the output end of the current detection subunit is connected to the input end of the current compensation subunit, and the output end of the current compensation subunit is connected to the M data lines; The current detection subunit is used to convert the current signals on the M feedback lines into voltage signals; The current compensation subunit is used to adjust the voltage signal, and output a compensation current to the M data lines based on the adjusted voltage signal.

8. The circuit according to claim 7, characterized in that The current detection subunit comprises a current detection resistor and an operational amplifier circuit, one end of the current detection resistor is connected to the M feedback lines, and the other end is connected to the ground end; The two input terminals of the operational amplifier circuit are respectively connected to the two ends of the current detection resistor.

9. The circuit according to claim 7, characterized in that The current compensation subunit includes a filter circuit and a load resistor; The input end of the filter circuit is connected to the output end of the current detection subunit, and the output end of the filter circuit is connected to one end of the load resistor; The other end of the load resistor is connected to the M data lines.

10. A photosensitive flat panel detector, characterized in that: The photosensitive flat panel detector comprises: the photosensitive unit array driving circuit according to any one of claims 1 to 9, and further comprises a timing controller, a scanning driving module, a signal receiving module, a signal processing module and an image generating module; The timing controller is connected to the scanning driving module, the scanning driving module is connected to N first scanning lines and N second scanning lines in the photosensitive unit array driving circuit, the signal receiving module is connected to M data lines in the photosensitive unit array driving circuit, the signal processing module is connected to the signal receiving module, and the image generating module is connected to the signal processing module; The timing controller is used to generate a scan timing instruction and send the scan timing instruction to the scan driving module; The scanning driving module is used to output a scanning driving signal to the current first scanning line under the control of the scanning timing instruction, and output a control signal to the current second scanning line after the scanning driving signal is turned off, so that the current release subunit in the photosensitive unit array driving circuit releases the leakage current; The signal receiving module is used to receive the induced current output by the M data lines, generate a signal to be processed based on the induced current, and send the signal to be processed to the signal processing module; The signal processing module is used to process the signal to be processed to obtain processed data for generating an image; The image generation module is used to generate a photosensitive image according to the processed data.

Images