X-ray detector temperature drift leakage current compensation method, system and equipment

Abstract

The invention provides a temperature drift leakage current compensation method for an X-ray detector, and the method comprises the steps: obtaining a leakage current temperature drift characteristic through a signal difference value of a response signal, thereby building a response signal relational expression, obtaining the actual temperature drift leakage current variable quantity of the X-ray detector according to the response signal relational expression, and updating the temperature drift leakage current in real time. Therefore, the real-time and accurate dynamic compensation of the temperature drift leakage current of the X-ray detector is realized, the image quality and sensitivity of the X-ray detector are not influenced in a wider temperature range, and meanwhile, the size of the PGA gear is adjusted in real time through the ASIC chip according to the temperature drift leakage current, so that the exposure saturation phenomenon is prevented. The invention further provides an X-ray detector temperature excursion leakage current compensation system and equipment. The X-ray detector temperature excursion leakage current compensation method is adopted for temperature excursion leakage current compensation.

Description

Technical Field

[0001] The present application relates to the field of detector detection technology, and in particular to a method, system and device for compensating temperature drift leakage current of an X-ray detector. Background Art

[0002] In the technical fields of security inspection, foreign body detection, etc. of X-ray detectors, sensors that sense natural light are basically based on silicon photodiodes to achieve light-to-electric conversion. The working performance of silicon photodiodes is significantly affected by the ambient temperature. As the ambient temperature changes, the background data output by the X-ray detector will change significantly, thus affecting the working performance of the X-ray detector. When the ambient temperature rises, the background information of the X-ray detector increases, and the noise increases, resulting in image distortion and reduced resolution performance. When the temperature rise is particularly severe, the background information of the X-ray detector directly exceeds the grayscale upper limit, making the X-ray detector completely unable to work normally.

[0003] Considering the problem of increased leakage current of silicon photodiodes in X-ray detectors caused by temperature drift, current X-ray detectors usually need to regularly update the bias correction module and gain correction module to meet the requirements of temperature drift correction, which requires pausing the system's host software and reinitializing the template update. In addition, the passive temperature drift compensation of existing X-ray detection systems has a low degree of intelligence, and the compensation effect is greatly affected by the environment. Summary of the invention

[0004] Based on the above-mentioned shortcomings, the purpose of this application is to provide a method, system and device for compensating temperature drift leakage current of an X-ray detector, which can realize real-time, accurate and dynamic temperature drift leakage current compensation through the inherent characteristics and working mechanism of the X-ray detector, thereby ensuring that the quality of the detected image is not affected within a wide temperature range and can effectively prevent the occurrence of exposure saturation.

[0005] In order to achieve the above-mentioned purpose and other related purposes, the present application provides a method for compensating temperature drift leakage current of an X-ray detector, comprising:

[0006] Acquiring a response signal of the X-ray detector;

[0007] Acquire a signal difference between two adjacent frames of the response signal, and determine the working state of the X-ray detector according to the signal difference;

[0008] According to the working state, obtaining the actual temperature drift leakage current change through the signal difference and updating the temperature drift leakage current;

[0009] According to the temperature drift leakage current, the response signal output is obtained, and the gain coefficient of the programmable gain amplifier is adjusted through the ASIC chip.

[0010] Optionally, the signal difference includes a first difference Δb and a second difference Δd, the first difference Δb is the signal difference in the working area of ​​the X-ray detector, and the second difference Δd is the signal difference in the shielding area of ​​the X-ray detector; the first difference Δb and the second difference Δd are compared with a preset leakage current change threshold T1 to determine the working state.

[0011] Optionally, the working state includes an initialization state and an exposure state;

[0012] When both the first difference Δb and the second difference Δd are smaller than the leakage current change threshold T1, determining that the working state of the X-ray detector is an initialization state;

[0013] When the first difference Δb or the second difference Δd is greater than or equal to the leakage current change threshold T1, it is determined that the working state of the X-ray detector is an exposure state.

[0014] Optionally, obtaining the actual temperature drift leakage current change includes the following steps:

[0015] When the working state is the initialization state, the actual temperature drift leakage current change is the signal difference;

[0016] When the working state is the exposure state, the actual temperature drift leakage current variation is obtained by querying a preset temperature drift coefficient comparison table according to the signal difference.

[0017] Optionally, in the X-ray detector temperature drift leakage current compensation method, before obtaining the actual temperature drift leakage current change and updating the temperature drift leakage current, the method further includes:

[0018] According to the signal difference, obtaining the leakage current temperature drift characteristic;

[0019] According to the leakage current temperature drift characteristic, the relationship between the response signal and the frame number is determined to obtain a response signal relationship equation.

[0020] Optionally, the leakage current temperature drift characteristics include equal interval change characteristics, piecewise linear change characteristics and multiple polynomial change characteristics.

[0021] Optionally, obtaining the response signal relationship equation includes the following steps:

[0022] According to a preset second time threshold T2, the response signal is divided into response signal data segments;

[0023] Determining an expression of the response signal relationship according to the leakage current temperature drift characteristics;

[0024] According to the response signal in a collection window in the response signal data segment, the unknown coefficients in the expression are calculated to obtain an equivalent response signal relational expression of the response signal data segment, thereby obtaining the response signal relational expression.

[0025] The present application provides an X-ray detector temperature drift leakage current compensation system, comprising:

[0026] A signal acquisition module, used to acquire a response signal of the X-ray detector;

[0027] a working state determining module, configured to calculate a signal difference between two adjacent frames of the response signal after acquiring the response signal from the signal acquiring module, so as to determine the working state of the X-ray detector;

[0028] A temperature drift leakage current acquisition module, configured to acquire the actual temperature drift leakage current change and update the temperature drift leakage current according to the signal difference after acquiring the working state from the working state determination module;

[0029] The signal output module is used to obtain the temperature drift leakage current from the temperature drift leakage current acquisition module, obtain the response signal output according to the temperature drift leakage current, and adjust the gain coefficient of the programmable gain amplifier through the ASIC chip.

[0030] Optionally, the X-ray detector temperature drift leakage current compensation system further includes:

[0031] a leakage current temperature drift characteristic acquisition module, configured to acquire the leakage current temperature drift characteristic of the X-ray detector according to the signal difference after acquiring the working state from the working state determination module;

[0032] The data processing module is used to obtain the leakage current temperature drift characteristic from the leakage current temperature drift characteristic acquisition module, and then obtain a response signal relationship expression of the response signal according to the leakage current temperature drift characteristic.

[0033] The present application provides an electronic device, including:

[0034] Processor; and

[0035] A memory communicatively connected to the processor; wherein,

[0036] The memory stores instructions that can be loaded and executed by the processor, and the instructions can be executed by the processor so that the processor can execute any one of the X-ray detector temperature drift leakage current compensation methods in the aforementioned embodiments.

[0037] The present application provides a storage medium storing a method for compensating temperature drift leakage current of an X-ray detector in any of the aforementioned embodiments that can be loaded and executed by a processor.

[0038] The X-ray detector temperature drift leakage current compensation method, system and device provided in this application have at least the following beneficial effects:

[0039] The X-ray detector temperature drift leakage current compensation method provided by the present application obtains a response signal in real time through the inherent characteristics and working mechanism of the X-ray detector, determines the working state of the X-ray detector according to the signal difference of the response signal of two adjacent frames, obtains the actual temperature drift leakage current change, and updates the temperature drift leakage current in real time, thereby realizing accurate dynamic compensation for the temperature drift leakage current of the X-ray detector, and the ASCI chip can adjust the size of the gain coefficient of the programmable gain amplifier in real time according to the feedback value of the temperature drift leakage current, thereby effectively preventing the exposure saturation phenomenon from occurring.

[0040] Furthermore, in the X-ray detector temperature drift leakage current compensation method provided by the present application, the leakage current temperature drift characteristics are obtained to establish a response signal relationship, the actual temperature drift leakage current change is obtained according to the response signal relationship, and the temperature drift leakage current is updated, thereby effectively improving the efficiency of the X-ray detector temperature drift leakage current compensation, and realizing fast and accurate dynamic compensation of the X-ray detector temperature drift leakage current.

[0041] The X-ray detector temperature drift leakage current compensation method provided in the present application can ensure that the detection image quality does not deteriorate for a long time, without the need to add an additional heat dissipation device on the system side, reducing the complexity of the system and the requirements of the X-ray detector on environmental conditions. At the same time, it ensures that the image quality and sensitivity of the X-ray detector are not affected within a wide temperature range and has a wide incident light response range. At the same time, the bias correction and gain correction can maintain long-term timeliness.

[0042] The X-ray detector temperature drift leakage current compensation system and device provided in the present application both adopt the above-mentioned X-ray detector temperature drift leakage current compensation method to perform temperature drift leakage current compensation, and therefore also have the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 Shown is a flow chart of a method for compensating temperature drift leakage current of an X-ray detector provided in the first embodiment of the present application.

[0045] Figure 2Shown is a flow chart of a method for compensating temperature drift leakage current of an X-ray detector provided in the second embodiment of the present application.

[0046] Figure 3a Shown is a schematic diagram of the working process of the X-ray detector temperature drift leakage current compensation system provided in the fourth embodiment of the present application.

[0047] Figure 3b Shown is a schematic diagram of the working process of the X-ray detector temperature drift leakage current compensation system provided in the optional embodiment of the fourth embodiment of the present application.

[0048] Figure 4 Shown is a schematic diagram of the structure of an electronic device provided in Example 5 of the present application. DETAILED DESCRIPTION

[0049] In order to make the technical purpose, technical scheme and technical effect of the embodiment of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Generally, the components of the embodiment of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0051] In the description of the present application, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0052] The working performance of X-ray detectors is greatly affected by the ambient temperature. As the ambient temperature changes, the temperature drift characteristics of the detector are particularly obvious. When the ambient temperature rises, the background information of the X-ray detector increases, the noise increases, resulting in image distortion and reduced resolution performance. In response to the above problems, current X-ray detectors usually need to regularly update the bias correction module and the gain correction module to meet the requirements of temperature drift correction. In addition, the passive temperature drift compensation of the existing detection system has a low degree of intelligence, and the compensation effect is greatly affected by the environment.

[0053] In the actual application of X-ray detectors, it can be considered that the temperature changes and responses of various parts of the X-ray detector are synchronous. Therefore, in response to the above problems, the present application provides an X-ray detector temperature drift leakage current compensation method, system and device, which can realize fast and accurate dynamic compensation of the X-ray detector temperature drift leakage current, especially for the X-ray linear detection system arranged in an L-shaped array.

[0054] In order to make the technical solution of the present application clearer, the relevant terms in the present application are explained before the specific embodiments, as follows:

[0055] Exposure state: the working state of the X-ray detector when incident light is incident;

[0056] Initialization state: the working state of the X-ray detector when there is no incident light;

[0057] Bias correction: eliminate the influence of X-ray detector background signal on response data at zero input;

[0058] Gain calibration: adjust and calibrate the gain of the X-ray detector to make it accurate, consistent, and meet the expected performance requirements;

[0059] PGA gear position: The gain factor of the programmable gain amplifier (PGA), which is used to control the amplification ratio of the digital analog signal;

[0060] Background signal: refers to the background signal detected when the X-ray detector starts working and is irrelevant to the expected response signal.

[0061] The specific embodiments are described in detail below:

[0062] Embodiment 1

[0063] This embodiment provides a method for compensating temperature drift leakage current of an X-ray detector, which can realize accurate dynamic compensation of temperature drift leakage current. Figure 1 The X-ray detector temperature drift leakage current compensation method provided in this embodiment includes steps S11 to S14, wherein:

[0064] Step S11: obtaining a response signal of the X-ray detector;

[0065] According to the working mechanism of the X-ray detector itself, the response signal of the X-ray detector is obtained, and the above response signal includes a response signal P and a response signal O; the response signal P is a response signal of the working area of ​​the X-ray detector, and the above working area refers to the detector area that can be irradiated by the incident light signal; the response signal O is a response signal of the shielding area of ​​the X-ray detector, and the shielding area refers to the detector area that cannot be irradiated by the incident light signal.

[0066] Step S12: Obtaining a signal difference and determining a working state of the X-ray detector;

[0067] The signal difference between two adjacent frames of response signals is obtained, and the working state of the X-ray detector is determined according to the preset leakage current change threshold T1.

[0068] In an optional embodiment, the signal difference includes a first difference Δb and a second difference Δd, the first difference Δb is a signal difference in a working area, and the second difference Δd is a signal difference in a shielding area. The first difference Δb is compared with a leakage current change threshold value T1, and when both the first difference Δb and the second difference Δd are less than the leakage current change threshold value T1, it is determined that the X-ray detector is working in an initialization state, and when the first difference Δb or the second difference Δd is not less than the leakage current change threshold value T1, it is determined that the X-ray detector is working in an exposure state.

[0069] Step S13: obtaining the actual temperature drift leakage current change and updating the temperature drift leakage current;

[0070] When the X-ray detector is working in an initialization state, the first difference Δb is used as the actual temperature drift leakage current variation Δ;

[0071] When the X-ray detector is working in the exposure state, the temperature drift leakage current change amount in the shielding area and the temperature drift leakage current change amount in the working area have a corresponding coefficient relationship, and the above coefficient relationship is only related to the inherent characteristics of the X-ray detector. Therefore, according to the second difference Δd, the actual temperature drift leakage current change amount Δ is obtained by querying the preset temperature drift coefficient comparison table. Optionally, for the jth pixel point in the working area, its actual temperature drift leakage current change amount Δ (j) is the second difference Δd (j) K (j) times, the actual temperature drift leakage current change Δ (j) k (j) *Δd (j) .

[0072] The temperature drift leakage current I is updated according to the actual temperature drift leakage current change Δ. Optionally, for the nth frame data, the temperature drift leakage current In =I n-1 +delta n , I1=O1-O0, where I n-1 is the temperature drift leakage current of the response signal of the n-1th frame, O0 is the intrinsic signal of the occluded area, and O1 is the response signal of the first frame of the occluded area.

[0073] Step S14: Obtain the response signal output OP and adjust the PGA gear size;

[0074] According to the obtained temperature drift leakage current I, the response signal output OP is obtained and the PGA gear size is adjusted. Optionally, for the nth frame data, the response signal output OP n =P n -I n ; will I n Compared with the preset leakage current saturation threshold T3, when I n When it is greater than the leakage current saturation threshold T3, the comparison result is fed back to the ASIC chip in the X-ray detector, and the PGA gear size is adjusted by the ASIC chip to suppress the amplification ratio of the analog signal digitization.

[0075] The X-ray detector temperature drift leakage current compensation method provided in this embodiment obtains the signal difference of the response signals of two adjacent frames through the response signal of the X-ray detector, obtains the temperature drift leakage current change Δ of the X-ray detector according to the signal difference, and updates the temperature drift leakage current in real time, thereby realizing accurate dynamic compensation for the temperature drift leakage current of the X-ray detector. The X-ray detector temperature drift leakage current compensation method provided in this embodiment can ensure that the quality of the detected image does not decrease for a long time by accurately and dynamically compensating the temperature drift leakage current of the X-ray detector, without adding an additional heat dissipation device on the system end, thereby reducing the complexity of the system; and reduces the requirements of the X-ray detector on environmental conditions, ensuring that the image quality and detector sensitivity are not affected in a wide temperature range, and having a wide incident light response range, and the bias correction and gain correction can maintain timeliness for a long time, effectively preventing the occurrence of exposure saturation.

[0076] Embodiment 2

[0077] This embodiment provides a method for compensating temperature drift leakage current of an X-ray detector, which obtains the temperature drift characteristics of the leakage current through the signal difference between two adjacent frames of response signals, thereby establishing a response signal relationship, and according to the response signal relationship, obtains the actual temperature drift leakage current change Δ and updates the temperature drift leakage current in real time, thereby achieving real-time and accurate dynamic compensation for the temperature drift leakage current. Figure 2 The same points as those in the first embodiment will not be described in detail, except that:

[0078] Step S21: obtaining a response signal of the X-ray detector;

[0079] According to the working mechanism of the X-ray detector itself, a response signal of the X-ray detector is obtained, and the response signal includes a response signal P, and the response signal P is a response signal of the working area.

[0080] Step S22: obtaining a signal difference to determine the working state of the X-ray detector;

[0081] A first difference Δb between two adjacent frame response signals P is obtained. When the first difference Δb is less than the first threshold current T1, the X-ray detector works in an initialization state, and the duration of the X-ray detector working continuously in the initialization state is greater than a preset first time threshold T4.

[0082] Step S23: obtaining the leakage current temperature drift characteristics of the X-ray detector;

[0083] When the X-ray detector is working in an initialization state, a leakage current temperature drift characteristic of the X-ray detector is obtained according to the first difference Δb. Optionally, the leakage current temperature drift characteristic includes an equal interval change characteristic, a piecewise linear change characteristic and a multiple polynomial change characteristic.

[0084] In an optional embodiment, the leakage current temperature drift characteristic is judged by the first difference Δb according to the preset second time threshold T2. When the X-ray detector is working in the initialization state, the response signal is divided into response signal data segments of length T2. In one of the response signal data segments, the first difference Δb is substantially 0, and the leakage current temperature drift characteristic is judged as an equal interval change characteristic. Optionally, the second time threshold T2 is the duration occupied by 1000 frames of response signals.

[0085] In another optional embodiment, within a response signal data segment, the first difference Δb is approximately a constant value, and the constant value is a non-zero value, then the leakage current temperature drift characteristic is determined to be a piecewise linear change characteristic. Optionally, within a response signal data segment, the same time interval T is obtained. r The signal difference Δb between the two response signals r , within the response signal data segment, Δb r If it is approximately a non-zero constant value, the leakage current temperature drift characteristic is determined to be a piecewise linear change characteristic.

[0086] In another optional embodiment, within a response signal data segment, the first difference Δb is constantly changing, and the leakage current temperature drift characteristic is determined to be a multiple polynomial change characteristic. Optionally, within a response signal data segment, the first difference Δb monotonically increases or decreases with the increase of the frame number.

[0087] Step S24: Obtaining a response signal relationship formula;

[0088] According to the leakage current temperature drift characteristics, the relationship between the response signal and the frame number is determined, and the expression of the response signal relationship is preliminarily established. According to the response signal, the unknown coefficients in the expression are calculated to obtain the response signal relationship.

[0089] In an optional embodiment, the leakage current temperature drift characteristic is an equally spaced variation characteristic, and the response signal is divided into response signal data segments according to the second time threshold T2. Optionally, the length of the response signal data segment is T2, and the second time threshold T2 is 5s. The response signal of the first acquisition window in the response signal data segment is obtained, and the average response signal of the first acquisition window of the response signal data segment is calculated, and the above average response signal is used as the equivalent response signal of the response signal data segment. The above operation is repeated until the equivalent response signals of all response signal data segments are obtained, thereby obtaining the response signal relationship of the response signal.

[0090] Optionally, the size of the acquisition window is 4, and the response signals of the first acquisition window of the mth segment of the response signal data segment are P m,1 , P m,2 , P m,3 and P m,4 , then the equivalent response signal P of the mth segment of the response signal data segment m =(P m,1 +P m,2 +P m,3 +P m,4 ) / 4.

[0091] In another optional embodiment, the leakage current temperature drift characteristic is a piecewise linear change characteristic, the response signal of the first acquisition window in the response signal data segment is obtained, the linear relationship formula of the first acquisition window of the response signal data segment is calculated, and the linear relationship formula is used as the equivalent linear relationship formula of the response signal data segment. The above operation is repeated until the equivalent linear relationship formulas of all response signal data segments are obtained, thereby obtaining the response signal relationship formula of the response signal.

[0092] Optionally, a response signal of the first acquisition window in the mth segment of the response signal data segment is obtained, the size of the acquisition window is at least 2, and according to the response signal, an equivalent linear relationship P of the mth segment of the response signal data segment is obtained. m (x) = K m *x+B m , x is the frame number of the corresponding response signal in the response signal data segment. Optionally, the equivalent linear relationship is obtained according to the least square method or the linear interpolation method.

[0093] In another optional embodiment, the leakage current temperature drift characteristic is a multi-time polynomial variation characteristic, and an expression of a multi-time polynomial is established according to the leakage current temperature drift characteristic, the response signal of the first acquisition window in the response signal data segment is obtained, the unknown coefficients in the expression of the multi-time polynomial are calculated, and the above expression is used as the equivalent multi-time polynomial of the response signal data segment, and the above operation is repeated until the equivalent multi-time polynomial of all response signal data segments is obtained, thereby obtaining the response signal relationship of the response signal. Optionally, the multi-time polynomial is obtained according to the least squares method or the interpolation method.

[0094] Optionally, a response signal of the first acquisition window in the mth segment of the response signal data segment is obtained, and the size of the acquisition window is at least 3. According to the response signal, the expression of the mth segment of the response signal data segment is calculated: The expression is used as an equivalent multi-order polynomial of the mth segment of the response signal data segment, wherein i is an integer from 0 to q, and q is the highest power of the multi-order polynomial.

[0095] Step S25: obtaining the actual temperature drift leakage current change, and updating the temperature drift leakage current in real time;

[0096] According to the response signal relationship, the actual temperature drift leakage current change Δ is obtained, and the temperature drift leakage current I is updated in real time.

[0097] In an optional embodiment, the leakage current temperature drift characteristic is an equal interval change characteristic, and the actual temperature drift leakage current change Δ between the mth segment and the m-1th segment of the response signal data segment m =P m -P m-1 , the temperature drift leakage current I of the mth segment of the response signal data segment m =delta m +I m-1 . Among them, when m=1, I1=P 1,1 -P0, P0 is the background signal of the detector.

[0098] In another optional embodiment, the leakage current temperature drift characteristic is a piecewise linear change characteristic, and the actual temperature drift leakage current change amount of adjacent frames in the mth segment of the response signal data segment is Δ m =K m *X, X is the frame interval, therefore, the temperature drift leakage current I of the nth frame in the mth segment of the response signal data segment m,n =I m,n-1 +Δ m , when n = 1, I m,n =I m,0 +Δ m =I m-1,N +Δ m , N is the number of frames of the response signal in the response signal data segment.

[0099] In another optional embodiment, the leakage current temperature drift characteristic is a multi-time polynomial change characteristic. According to the equivalent multi-time polynomial, the actual temperature drift leakage current change Δ of the nth frame in the mth segment of the response signal data segment is m,n =P m,n (x)-P m,n-1 (x-1), temperature drift leakage current I m,n =Δ m,n +I m,n-1 , when n=1,Δ m,1 =P m,1 (x)-P m,0 (x-1), I m,1 =Δ m,1 +I m-1,N , x is the frame number of the corresponding response signal, and N is the number of frames of the response signal in the response signal data segment.

[0100] Step S26: Obtain the response signal output OP and adjust the PGA gear size.

[0101] It should be noted that in steps S21 to S26 of this embodiment, when the X-ray detector is working in the exposure state, the processing and compensation process of the response signal are all carried out in real time, and steps S21 to S26 are not performed only after the response signal acquisition process is completed. In this embodiment, the response signal is divided into individual response signal data segments. The above operation is only for the convenience of description and is not a limitation of this application.

[0102] The X-ray detector temperature drift leakage current compensation method provided in this embodiment obtains the signal difference of two adjacent frames of response signals according to the response signal, thereby obtaining the actual temperature drift leakage current change of the detector and updating the temperature drift leakage current, and thus has the same beneficial effects as the first embodiment.

[0103] In addition, in the X-ray detector temperature drift leakage current compensation method provided by the present embodiment, the leakage current temperature drift characteristics are obtained according to the above-mentioned signal difference, and the response signal relationship is further obtained to obtain the actual temperature drift leakage current change, and the temperature drift leakage current is updated in real time, which effectively improves the efficiency of the X-ray detector temperature drift leakage current compensation, realizes faster dynamic compensation of the X-ray detector temperature drift leakage current, improves the applicability of the X-ray detector, and reduces the dependence of the X-ray detector on the environment.

[0104] Embodiment 3

[0105] This embodiment provides a method for compensating temperature drift leakage current of an X-ray detector. Figure 2 The same points as those in the first embodiment will not be described in detail, except that:

[0106] Step S22: obtaining a signal difference to determine the working state of the X-ray detector;

[0107] A signal difference between two adjacent frame response signals is obtained, where the signal difference includes a first difference Δb and a second difference Δd. When the first difference Δb and the second difference Δd are less than the leakage current change threshold T1, the X-ray detector operates in an initialization state. Meanwhile, the time length during which the X-ray detector continuously operates in the initialization state is greater than a first time threshold T4. When the first difference Δb or the second difference Δd is greater than or equal to the leakage current change threshold T1, the X-ray detector operates in an exposure state.

[0108] Step S23: obtaining the leakage current temperature drift characteristics of the X-ray detector;

[0109] When the X-ray detector is working in an initialization state, the leakage current temperature drift characteristic of the X-ray detector is obtained according to the first difference Δb. Optionally, the leakage current temperature drift characteristic includes an equal interval change characteristic, a piecewise linear change characteristic and a multiple polynomial change characteristic.

[0110] Step S24: Obtaining a response signal relationship;

[0111] According to the leakage current temperature drift characteristics, the relationship between the response signal and the frame number is determined, an expression of the response signal relationship is preliminarily established, and according to the response signal, the unknown coefficients in the expression are calculated to obtain the response signal relationship.

[0112] In an optional embodiment, the leakage current temperature drift characteristic is an equally spaced variation characteristic, and the response signal is divided into response signal data segments according to the second time threshold T2. The response signal of the first acquisition window in the response signal data segment is obtained, and the average response signal of the first acquisition window of the response signal data segment is calculated, and the average response signal is used as the equivalent response signal of the response signal data segment, and the above operation is repeated until the equivalent response signals of all response signal data segments are obtained, thereby obtaining the response signal relationship of the response signal.

[0113] In another optional embodiment, the leakage current temperature drift characteristic is a piecewise linear change characteristic, the response signal of the first acquisition window in the response signal data segment is obtained, the linear relationship of the first acquisition window of the response signal data segment is calculated, and the linear relationship is used as the equivalent linear relationship of the response signal data segment, thereby obtaining the response signal relationship of the response signal.

[0114] In another optional embodiment, the leakage current temperature drift characteristic is a multi-time polynomial change characteristic. According to the leakage current temperature drift characteristic, an expression of the multi-time polynomial of the response signal is established, the response signal of the first acquisition window in the response signal data segment is obtained, the unknown coefficients in the expression are calculated, and the expression is used as the equivalent multi-time polynomial of the response signal data segment, thereby obtaining the response signal relationship of the response signal.

[0115] Step S25: obtaining the actual temperature drift leakage current change, and updating the temperature drift leakage current in real time;

[0116] According to the second difference Δd, the first actual temperature drift leakage current change Δ1 is obtained; according to the response signal relationship, the second actual temperature drift leakage current change Δ2 is obtained. According to Δ1 and Δ2, the actual temperature drift leakage current change Δ is obtained, and the temperature drift leakage current I is updated in real time.

[0117] When the X-ray detector is working in the initialization state, the second difference Δd in the shielding area is used as the first actual temperature drift leakage current change Δ1, and the first difference Δb in the working area is used as the second actual temperature drift leakage current change Δ2. When the X-ray detector is working in the exposure state, according to the second difference Δd, by querying the preset temperature drift coefficient comparison table, the first actual temperature drift leakage current change Δ1 is obtained; according to the established response signal relationship, the second actual temperature drift leakage current change Δ2 is obtained; according to Δ1 and Δ2, the actual temperature drift leakage current change Δ is obtained. Optionally, the actual temperature drift leakage current change Δ=(Δ1+Δ2) / 2, and the temperature drift leakage current I is updated in real time according to Δ.

[0118] Step S26: Obtain the response signal output OP and adjust the PGA gear size.

[0119] The method for compensating the temperature drift leakage current of an X-ray detector provided in this embodiment obtains the signal difference of the response signal of two adjacent frames according to the response signal, thereby obtaining the actual temperature drift leakage current change of the X-ray detector and updating the temperature drift leakage current, and thus has the same beneficial effects as the first embodiment.

[0120] In addition, the X-ray detector temperature drift leakage current compensation method provided in this embodiment obtains the first actual temperature drift leakage current change Δ1 and the second actual temperature drift leakage current change Δ2 according to the response signal P of the working area and the response signal O of the shielding area, thereby obtaining the actual temperature drift leakage current change Δ, and updates the temperature drift leakage current in real time, thereby realizing more accurate dynamic compensation for the detector temperature drift leakage current.

[0121] Embodiment 4

[0122] This embodiment provides an X-ray detector temperature drift leakage current compensation system, referring to Figure 3a, including a signal acquisition module, a working state determination module, a temperature drift leakage current processing module and a signal output module. Among them:

[0123] The signal acquisition module is used to acquire the response signal of the X-ray detector. According to the working mechanism of the X-ray detector itself, the response signal P of the working area of ​​the X-ray detector and the response signal O of the shielding area are acquired.

[0124] The working state determination module is used to determine the working state of the X-ray detector after the response signal is obtained from the signal acquisition module. The signal difference of the response signals of two adjacent frames is obtained, and the working state of the X-ray detector is determined according to the signal difference. The working state includes an initialization state and an exposure state, and the signal difference includes a first difference Δb and a second difference Δd, the first difference Δb is the signal difference of the working area, and the second difference Δd is the signal difference of the shielding area.

[0125] The first difference Δb and the second difference Δd are compared with a preset leakage current change threshold value T1. When both the first difference Δb and the second difference Δd are less than the leakage current change threshold value T1, the X-ray detector operates in an initialization state. Optionally, the duration for which the X-ray detector continuously operates in the initialization state is greater than a preset first time threshold value T4. When the first difference Δb or the second difference Δd is not less than the leakage current change threshold value T1, the X-ray detector operates in an exposure state.

[0126] The temperature drift leakage current acquisition module is used to obtain the actual temperature drift leakage current change Δ and update the temperature drift leakage current I in real time after the working state determination module determines the working state.

[0127] According to the signal difference between the response signals of two adjacent frames, the actual temperature drift leakage current change Δ is obtained, and the temperature drift leakage current I is updated in real time. Optionally, when the X-ray detector works in the initialization state, the first difference Δb is used as the actual temperature drift leakage current change Δ; when the X-ray detector works in the exposure state, according to the second difference Δd, the actual temperature drift leakage current change Δ is obtained by querying a preset temperature drift coefficient comparison table.

[0128] The signal output module is used to obtain the response signal output and adjust the PGA gear after obtaining the temperature drift leakage current from the temperature drift leakage current acquisition module.

[0129] According to the temperature drift leakage current I, the response signal output OP is obtained and the PGA gear size is adjusted by the ASIC chip in the X-ray detector. For the nth frame response signal, the corresponding response signal output OP n =P n -I n ; will I n Compared with the preset leakage current saturation threshold T3, when In When it is greater than or equal to the leakage current saturation threshold T3, the comparison result is fed back to the ASIC chip, and the PGA gear size is adjusted by the ASIC chip to suppress the amplification ratio of the analog signal digitization.

[0130] In an alternative embodiment, reference Figure 3b The X-ray detector temperature drift leakage current compensation system also includes a leakage current temperature drift characteristic acquisition module and a data processing module, wherein:

[0131] The leakage current temperature drift characteristic acquisition module is used to acquire the leakage current temperature drift characteristic of the X-ray detector after the working state is acquired by the working state determination module. When the X-ray detector is working in the initialization state, the leakage current temperature drift characteristic is acquired according to the first difference Δb, and the leakage current temperature drift characteristic includes an equal interval change characteristic, a piecewise linear change characteristic, and a multiple polynomial change characteristic.

[0132] The data processing module is used to obtain the relationship between the response signal and the frame number after the leakage current temperature drift characteristic is obtained by the leakage current temperature drift characteristic acquisition module, so as to determine the response signal relationship. According to the leakage current temperature drift characteristic obtained by the leakage current temperature drift characteristic acquisition module, the expression of the response signal relationship is preliminarily established, and according to the response signal, the unknown coefficient in the expression is calculated to obtain the response signal relationship.

[0133] The temperature drift leakage current acquisition module is used to obtain the actual temperature drift leakage current change Δ and update the temperature drift leakage current I in real time after obtaining the response signal relationship from the data processing module.

[0134] In an optional embodiment, the actual temperature drift leakage current variation Δ is obtained according to the response signal relationship obtained by the data processing module, and the temperature drift leakage current I is updated in real time.

[0135] In another optional embodiment, when the X-ray detector is working in the initialization state, the second difference Δd is used as the first actual temperature drift leakage current change Δ1, and the first difference Δb is used as the second actual temperature drift leakage current change Δ1; when the X-ray detector is working in the exposure state, according to the second difference Δd, by querying a preset temperature drift coefficient comparison table, the first actual temperature drift leakage current change Δ1 is obtained, and according to the response signal relationship, the second actual temperature drift leakage current change Δ2 is obtained. According to the Δ1 and Δ2, Δ is obtained, and optionally, Δ=(Δ1+Δ2) / 2.

[0136] The X-ray detector temperature drift leakage current compensation system provided in this embodiment adopts any one of the X-ray detector temperature drift leakage current compensation methods in embodiments one to three to perform temperature drift leakage current compensation. Therefore, the X-ray detector temperature drift leakage current compensation system provided in this embodiment also has the beneficial effects of the above embodiments.

[0137] Embodiment 5

[0138] This embodiment provides an electronic device, including a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and execute any one of the X-ray detector temperature drift leakage current compensation methods provided in the present application.

[0139] Figure 4 The schematic diagram of the structure of the electronic device exemplified in this embodiment. The electronic device includes: a processor 41, a memory 42, an input and output interface 43, a communication interface 44 and a communication bus 45. The memory 42 is used to store a computer program 422, and the computer program 422 can be loaded by the processor 41 and execute any X-ray detector temperature drift leakage current compensation method provided in this application. The electronic device provided in this embodiment represents various forms of digital computers, such as desktop computers, workbenches, servers, mainframe computers and other suitable computers, and can also represent various forms of mobile devices, such as smart phones, wearable devices and other similar computing devices.

[0140] In this embodiment, the communication interface 44 can build a data transmission channel between the electronic device and the external device, the input and output interface 43 is used to obtain external input data or output data to the outside world, and the operating system 421 is used to control various hardware devices and computer programs 422 on the electronic device. In addition to including a program that can execute any X-ray detector temperature drift leakage current compensation method provided in this application, the computer program 422 can further include a computer program that can perform other tasks.

[0141] Embodiment 6

[0142] This embodiment provides a storage medium storing a computer program of any X-ray detector temperature drift leakage current compensation method provided in the present application that can be loaded and executed by a processor.

[0143] The storage medium includes a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), an electrically programmable ROM, or an optical disk, and other storage media that can store program codes.

[0144] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for compensating temperature drift leakage current of an X-ray detector, characterized in that: The following steps are involved: Acquiring a response signal of the X-ray detector; Acquire a signal difference between two adjacent frames of the response signal, and determine the working state of the X-ray detector according to the signal difference; According to the working state, obtaining the actual temperature drift leakage current change through the signal difference and updating the temperature drift leakage current; According to the temperature drift leakage current, the response signal output is obtained, and the gain coefficient of the programmable gain amplifier is adjusted through the ASIC chip.

2. The X-ray detector temperature drift leakage current compensation method according to claim 1, characterized in that: The signal difference includes a first difference Δb and a second difference Δd, the first difference Δb is the signal difference in the working area of ​​the X-ray detector, and the second difference Δd is the signal difference in the shielding area of ​​the X-ray detector; the first difference Δb and the second difference Δd are compared with a preset leakage current change threshold T1 to determine the working state.

3. The X-ray detector temperature drift leakage current compensation method according to claim 2, characterized in that: The working state includes an initialization state and an exposure state; When both the first difference Δb and the second difference Δd are smaller than the leakage current change threshold T1, determining that the working state of the X-ray detector is an initialization state; When the first difference Δb or the second difference Δd is greater than or equal to the leakage current change threshold T1, it is determined that the working state of the X-ray detector is an exposure state.

4. The X-ray detector temperature drift leakage current compensation method according to claim 1 or 3, characterized in that: Obtaining the actual temperature drift leakage current change includes the following steps: When the working state is the initialization state, the actual temperature drift leakage current change is the signal difference; When the working state is the exposure state, the actual temperature drift leakage current variation is obtained by querying a preset temperature drift coefficient comparison table according to the signal difference.

5. The X-ray detector temperature drift leakage current compensation method according to claim 1, characterized in that: Before obtaining the actual temperature drift leakage current change, it also includes: According to the signal difference, obtaining the leakage current temperature drift characteristic; According to the leakage current temperature drift characteristic, the relationship between the response signal and the frame number is determined to obtain a response signal relationship equation.

6. The X-ray detector temperature drift leakage current compensation method according to claim 5, characterized in that: The leakage current temperature drift characteristics include equal interval change characteristics, piecewise linear change characteristics and multiple polynomial change characteristics.

7. The X-ray detector temperature drift leakage current compensation method according to claim 5, characterized in that: Obtaining the response signal relationship includes the following steps: According to a preset second time threshold T2, the response signal is divided into response signal data segments; Determining an expression of the response signal relationship according to the leakage current temperature drift characteristics; According to the response signal in a collection window in the response signal data segment, the unknown coefficients in the expression are calculated to obtain an equivalent response signal relational expression of the response signal data segment, thereby obtaining the response signal relational expression.

8. An X-ray detector temperature drift leakage current compensation system, characterized in that: include: A signal acquisition module, used to acquire a response signal of the X-ray detector; a working state determining module, configured to calculate a signal difference between two adjacent frames of the response signal after acquiring the response signal from the signal acquiring module, so as to determine the working state of the X-ray detector; A temperature drift leakage current acquisition module, configured to acquire the actual temperature drift leakage current change and update the temperature drift leakage current according to the signal difference after acquiring the working state from the working state determination module; The signal output module is used to obtain the temperature drift leakage current from the temperature drift leakage current acquisition module, obtain the response signal output according to the temperature drift leakage current, and adjust the gain coefficient of the programmable gain amplifier through the ASIC chip.

9. The X-ray detector temperature drift leakage current compensation system according to claim 8, characterized in that: Also includes: a leakage current temperature drift characteristic acquisition module, configured to acquire the leakage current temperature drift characteristic of the X-ray detector according to the signal difference after acquiring the working state from the working state determination module; The data processing module is used to obtain the leakage current temperature drift characteristic from the leakage current temperature drift characteristic acquisition module, and then obtain a response signal relationship expression of the response signal according to the leakage current temperature drift characteristic.

10. An electronic device, characterized in that: include: processor; as well as A memory communicatively connected to the processor; wherein, The memory stores instructions that can be loaded and executed by the processor, and the instructions can be executed by the processor so that the processor can execute the X-ray detector temperature drift leakage current compensation method according to any one of claims 1 to 7.

11. A storage medium, characterized in that: The method for compensating temperature drift leakage current of an X-ray detector according to any one of claims 1 to 7 is stored and can be loaded and executed by a processor.

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