Pixel array driving state correction method and correction circuit module

Abstract

The invention provides a pixel array driving state correction method and a correction circuit module. The correction method is applied to a readout circuit of a focal plane array detector, and comprises the following steps: sending a first frame offset gear adjustment parameter to a pixel array, and controlling pixels to be in a first driving state, the first frame offset gear adjustment parameter comprising an offset gear adjustment parameter of each pixel; in the first driving state, the pixel array inputs first frame image data; a second frame of offset gear adjusting parameter is sent, the pixels are controlled to be in a second driving state, and the second frame of offset gear adjusting parameter comprises the offset gear adjusting parameter of each pixel; in a second driving state, the pixel array inputs second frame image data; according to the difference value between the correction target value and the second frame of image data and the difference value between the second frame of image data and the first frame of image data, correction parameters of the pixel array driving state are obtained, the correction parameters comprise a plurality of sub-correction parameters, and the sub-correction parameters are in one-to-one correspondence with the pixels.

Description

Technical Field

[0001] The present application relates to the technical field of signal imaging, and particularly relates to a method for correcting the driving state of a pixel array and a correction circuit module. Background Art

[0002] A focal plane array detector is a detector that converts signals such as infrared, visible light, and ultraviolet into electrical signals through photoelectric conversion and processes them to obtain a video image of an object. Its core components include a pixel array that receives signal radiation and a readout circuit that collects data generated by the pixels and realizes amplification and output.

[0003] A focal plane array pixel is a sensitive unit with a double-layer or multi-layer microbridge structure and an umbrella structure processed by MEMS technology, and its size can be as small as several micrometers. An array composed of a large number of pixels is called a focal plane array. Currently, with the reduction of pixel size, the scale of the focal plane array has developed from 640×512 to 1024×1024, and can even reach a scale of 2048×2048.

[0004] A readout circuit is a circuit that reads tiny signals, amplifies, filters, converts, and outputs them. In a focal plane array detector, the readout circuit realizes collecting data of each pixel in the array, amplifying it, and performing analog-to-digital conversion and then outputting. The readout circuit generally includes a pixel bias circuit, a pixel signal conversion circuit, a pixel array control circuit, etc. The pixel bias circuit of the readout circuit realizes connecting the pixel to the circuit, integrating, sampling, and amplifying its current to realize preliminary signal acquisition. The pixel signal conversion circuit of the readout circuit realizes converting the analog signal generated by the pixel bias circuit into a digital signal with a certain accuracy. The pixel array control circuit in the readout circuit, on the one hand, realizes connecting the array pixels row by row to the pixel bias circuit, and on the other hand, realizes orderly outputting the pixel data that has completed analog-to-digital conversion to the outside of the chip.

[0005] To save the area of the processor, and at the same time because the readout circuit adopts a method of integrating pixels row by row, the pixel bias circuit in the readout circuit generally adopts a method of sharing at the column level, that is, each column of pixels shares a pixel bias circuit.

[0006] During the manufacturing process of the pixels of the focal plane array, problems such as uneven doping distribution of materials or processing accuracy often lead to inconsistencies in the size, distribution, thickness, etc. among the array pixels. This further causes differences in the electrical and thermodynamic properties of the array pixels, resulting in the widespread problem of non-uniformity in infrared focal plane array detectors. The existence of non-uniformity makes the response characteristics of the focal plane array pixels to external signals inconsistent. For example, when the detector receives a uniformly distributed signal, pixels with different characteristics will output different values. The non-uniformity problem causes deviations in the detection results of the detector, seriously affecting its imaging quality.

[0007] Focal plane array detectors widely use non-uniformity correction methods to improve the imaging quality of the detectors. Traditional correction methods usually adopt a successive approximation correction strategy. For large array detectors with many bias adjustment steps, the above correction method obtains the optimal correction parameters relatively slowly. Taking a large array detector with 32 bias adjustment steps as an example, it is necessary for the detector to collect at least 16 frames of data before the optimal correction parameters can be obtained. Such a high frame delay will inevitably cause the corresponding detector product to have slow imaging after startup, which is not conducive to enhancing the market competitiveness of the product. Summary of the Invention

[0008] The first aspect of the embodiments of the present application provides a method for correcting the driving state of a pixel array. The correction method is applied to the readout circuit of a focal plane array detector and is used to correct the pixel driving state of the pixel array in the focal plane array detector. The correction method includes: Sending a first-frame bias adjustment parameter to the pixel array to control each pixel of the pixel array to be in a first driving state, where the first-frame bias adjustment parameter includes the bias adjustment parameter of each pixel; In the first driving state, the pixel array inputs the first-frame image data; Sending a second-frame bias adjustment parameter to the pixel array to control each pixel of the pixel array to be in a second driving state, where the second-frame bias adjustment parameter includes the bias adjustment parameter of each pixel; In the second driving state, the pixel array inputs the second-frame image data; Obtaining the correction parameter of the driving state of the pixel array according to the difference between the correction target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data, where the correction parameter includes a plurality of sub-correction parameters, and each sub-correction parameter corresponds to each pixel of the pixel array one by one.

[0009] In some embodiments, an addition operation is used to compensate for the division operation to obtain the correction parameter of the driving state of the pixel array.

[0010] In some embodiments, a circuit is used to perform the operation of C = [A+(B / 2N)] / (B / N) to obtain the correction parameter: where A is the difference between the correction target value and the second-frame image data, B is the difference between the second-frame image data and the first-frame image data, N is the gear difference between the bias gear corresponding to the second-frame bias gear adjustment parameter and the bias gear corresponding to the first-frame bias gear adjustment parameter, and C is the obtained correction parameter.

[0011] In some embodiments, the bias gear corresponding to the second-frame bias gear adjustment parameter is adjacent to the bias gear corresponding to the first-frame bias gear adjustment parameter, and the value of N is 1. The operation of C = (A + B / 2) / B is performed to obtain the correction parameter.

[0012] In some embodiments, the correction method further includes: Adjusting the second-frame bias gear adjustment parameter by the obtained correction parameter to form an updated bias gear adjustment parameter, where the updated bias gear adjustment parameter includes bias gear adjustment sub-parameters corresponding to each pixel; Sending the updated bias gear adjustment parameter to the pixel array to control each pixel of the pixel array to be in a third driving state; In the third driving state, the pixel array performs signal detection and obtains one or more subsequent frames of image data.

[0013] A second aspect of the embodiments of the present application provides a correction circuit module, which is applied to the readout circuit of a focal plane array detector and is used to correct the pixel driving state of the pixel array in the focal plane array detector. The correction circuit module includes a driving configuration circuit, a framing control circuit, a parameter operation circuit, a memory, and a central control circuit. The driving configuration circuit is used to refresh the driving configuration parameters of each pixel in the pixel array and control the driving state of the pixel; the framing control circuit is used to receive the data generated by the pixel array and integrate it into an effective DVP timing; the parameter operation circuit is used to complete parameter operations and is used for enabling control of data writing into the memory and reading out from the memory; the central control circuit is used to control the driving configuration circuit and the parameter operation circuit. The focal plane array detector has a pixel driving state correction mode. In the pixel driving state correction mode, the central control circuit controls the driving configuration circuit to send a first frame of bias level adjustment parameters to the pixel array to control each pixel of the pixel array to be in a first driving state, where the first frame of bias level adjustment parameters includes the bias level adjustment parameters of each pixel; in the first driving state, the pixel array inputs first-frame image data; the central control circuit controls the driving configuration circuit to send a second frame of bias level adjustment parameters to the pixel array to control each pixel of the pixel array to be in a second driving state, where the second frame of bias level adjustment parameters includes the bias level adjustment parameters of each pixel; in the second driving state, the pixel array inputs second-frame image data; under the control of the central control circuit, the parameter operation circuit obtains the correction parameters of the pixel array driving state according to the difference between the correction target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data, where the correction parameters include a plurality of sub-correction parameters, and each sub-correction parameter corresponds to each pixel of the pixel array one by one.

[0014] In some embodiments, the parameter operation circuit compensates the division operation by using an addition operation to obtain the correction parameters of the pixel array driving state.

[0015] In some embodiments, the parameter operation circuit obtains the correction parameters by performing the operation of C = [A + (B / 2N)] / (B / N), where A is the difference between the correction target value and the second-frame image data, B is the difference between the second-frame image data and the first-frame image data, N is the level difference between the bias level corresponding to the second-frame bias level adjustment parameters and the bias level corresponding to the first-frame bias level adjustment parameters, and C is the obtained correction parameter.

[0016] In some embodiments, the bias level corresponding to the second-frame bias level adjustment parameters is adjacent to the bias level corresponding to the first-frame bias level adjustment parameters, and the value of N is 1. The correction parameters are obtained by performing the operation of C = (A + B / 2) / B.

[0017] In some embodiments, the parameter operation circuit forms updated bias level adjustment parameters according to the obtained correction parameters and the second-frame bias level adjustment parameters, where the updated bias level adjustment parameters include bias level adjustment sub-parameters corresponding to each pixel; the central control circuit controls the driving configuration circuit to send the updated bias level adjustment parameters to the pixel array to control each pixel of the pixel array to be in a third driving state; in the third driving state, the pixel array inputs one or more subsequent frames of image data.

[0018] In some embodiments, in the pixel driving state correction mode, the central control circuit further controls the parameter operation circuit to write the first frame of image data into the memory.

[0019] In some embodiments, in the pixel driving state correction mode, the central control circuit further controls the parameter operation circuit to write the second frame of image data into the memory.

[0020] In some embodiments, the correction circuit module is integrated in the readout circuit.

[0021] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0023] Figure 1 It is a schematic flow chart of a method for correcting the driving state of a pixel array provided by an embodiment of this application; Figure 2 It is a schematic diagram of a correction circuit module provided by an embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Here, the technical solutions in the embodiments (or "embodiment modes") of this application will be clearly and completely described in conjunction with the drawings. When the following description involves the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0025] If there are terms related to directional indications or positional relationships in the embodiments of this application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movement conditions between components in a specific posture; if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, terms such as "first" and "second" in the embodiments of this application are only for the purpose of convenient description and cannot be understood as indicating or implying relative importance.

[0026] As described above, the successive approximation calibration strategy adopted by the traditional calibration method results in a slow speed of obtaining the optimal calibration parameters. To improve the above defects, an embodiment of the present application provides a calibration method for the driving state of a pixel array, which can be applied to the readout circuit of a focal plane array detector and is used to calibrate the pixel driving state of the pixel array in the focal plane array detector. As Figure 1 shown, the calibration method includes: Step S10: Send the first-frame bias level adjustment parameters to the pixel array to control each pixel of the pixel array to be in the first driving state, where the first-frame bias level adjustment parameters include the bias level adjustment parameters of each pixel; Step S20: When the first-frame image data corresponding to the pixel array in the first driving state is input, store the first-frame image data; Step S30: Send the second-frame bias level adjustment parameters to the pixel array to control the pixels of the pixel array to be in the second driving state, where the second-frame bias level adjustment parameters include the bias level adjustment parameters of each pixel; Step S40: When the second-frame image data corresponding to the pixel array in the second driving state is input, store the second-frame image data; Step S50: Obtain the calibration parameters of the driving state of the pixel array according to the difference between the calibration target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data, where the calibration parameters include a plurality of sub-calibration parameters, and each sub-calibration parameter corresponds to each pixel of the pixel array one by one.

[0027] Using the above calibration method in the above embodiments, large-array detectors with multiple bias adjustment levels can all obtain the optimal calibration parameters within two frames of time, and thus can meet the requirement of high-efficiency and fast image output after the detector is powered on.

[0028] In the above embodiment, the bias level adjustment parameters of each pixel included in the first-frame bias level adjustment parameters can be either all the same or not completely the same. That is, in the first-frame bias level adjustment parameters, the bias level adjustment parameters of each pixel can be set independently of each other. Taking an array detector with 32 bias adjustment levels (the 32 levels included are the 0th level, the 1st level, the 2nd level,..., the 29th level, the 30th level, and the 31st level) as an example, each pixel can be set to different levels or the same level. In the first-frame bias level adjustment parameters, the set values of the bias level adjustment parameters of each pixel do not affect or hardly affect the final calibration result. In one embodiment, the bias level adjustment parameters of each pixel can all be set to the 0th level.

[0029] In the above embodiments, the first-frame image data includes the gray-scale values of each pixel. That is, the first-frame image data input from the pixel array to the readout circuit contains the gray-scale values of each pixel in the first driving state.

[0030] In the above embodiments, the bias level adjustment parameters of each pixel included in the second-frame bias level adjustment parameters may all be the same or may not be completely the same. That is, in the second-frame bias level adjustment parameters, the bias level adjustment parameters of each pixel can be set independently of each other. Taking an array detector with 32 bias adjustment levels (the 32 levels included are the 0th level, the 1st level, the 2nd level,..., the 29th level, the 30th level, and the 31st level) as an example, in the second-frame bias level adjustment parameters, each pixel can be set to different levels or the same level. Similarly, in the second-frame bias level adjustment parameters, the set values of the bias level adjustment parameters of each pixel do not affect or hardly affect the final calibration result. In one embodiment, in the second-frame bias level adjustment parameters, the bias level adjustment parameters of each pixel can all be set to the 1st level or all be set to the 2nd level.

[0031] In the above embodiments, the second-frame image data includes the gray-scale values of each pixel. That is, the second-frame image data input from the pixel array to the readout circuit contains the gray-scale values of each pixel in the second driving state.

[0032] In the above embodiments, the calibration target value corresponds to the gray-scale value of the image, which can be set or selected according to user requirements. For example, it can be 8000. Generally speaking, for each pixel in the pixel array, their calibration target values are usually the same. For example, they can all be 8000. The "difference between the calibration target value and the second-frame image data" mentioned in the text refers to the difference between the calibration target value and the gray-scale value corresponding to the second-frame image. For each pixel, the difference between the calibration target value and the gray-scale value corresponding to its second-frame image may not be equal. The "difference between the second-frame image data and the first-frame image data" mentioned in the text refers to the difference between the gray-scale value corresponding to the second-frame image and the gray-scale value corresponding to the first-frame image. For each pixel, the difference between the gray-scale value corresponding to its second-frame image and the gray-scale value corresponding to its first-frame image may not be equal.

[0033] In some embodiments, the division operation can be compensated by an addition operation to obtain the correction parameter. For example, a characteristic circuit of C = [A + (B / 2N)] / (B / N) can be designed to ensure the accuracy of the correction parameter. Wherein, A is the difference between the correction target value and the second-frame image data, B is the difference between the second-frame image data and the first-frame image data, N is the gear difference between the bias gear corresponding to the second-frame bias gear adjustment parameter and the bias gear corresponding to the first-frame bias gear adjustment parameter, and C is the obtained correction parameter.

[0034] When the bias gear corresponding to the second-frame bias gear adjustment parameter is adjacent to the bias gear corresponding to the first-frame bias gear adjustment parameter, the value of N can be 1 or -1. For example, when the first-frame bias gear adjustment parameter of a pixel is set to the 0th gear and the second-frame bias gear adjustment parameter of the same pixel is set to the 1st gear, the corresponding gear difference N is equal to 1. Correspondingly, the correction parameter is obtained by performing the operation of C = (A + B / 2) / B. When the value of N is 1, the amount of calculation can be reduced and the correction speed can be further accelerated. Another example is when the first-frame bias gear adjustment parameter of a pixel is set to the 31st gear and the second-frame bias gear adjustment parameter of the same pixel is set to the 30th gear, the corresponding gear difference N is equal to -1. When the value of N is -1, the amount of calculation can be reduced and the correction speed can be further accelerated.

[0035] When the bias gear corresponding to the second-frame bias gear adjustment parameter is not adjacent to the bias gear corresponding to the first-frame bias gear adjustment parameter, the value of N is an integer greater than 1 or less than -1. For example, when the first-frame bias gear adjustment parameter of a pixel is set to the 0th gear and the second-frame bias gear adjustment parameter of the same pixel is set to the 2nd gear, the corresponding gear difference N is equal to 2. Correspondingly, the correction parameter is obtained by performing the operation of C = (A + B / 4) / (B / 2). Another example is when the first-frame bias gear adjustment parameter of a pixel is set to the 31st gear and the second-frame bias gear adjustment parameter of the same pixel is set to the 29th gear, the corresponding gear difference N is equal to -2.

[0036] In the above embodiments, the correction parameter C corresponds to the gear value that each pixel needs to be further adjusted on the basis of the second-frame bias gear adjustment parameter. For a pixel, when the calculated C value is equal to 0, the second-frame bias gear at which the pixel is currently located is its optimal bias gear; when the calculated C value is equal to 1, the second-frame bias gear of the pixel needs to be adjusted upward by one gear; when the calculated C value is equal to N, the second-frame bias gear of the pixel needs to be adjusted upward by N gears. For example, when the first-frame bias gear adjustment parameter of a pixel is set to gear 0 and the second-frame bias gear adjustment parameter of the pixel is set to gear 2, and the correction parameter C obtained according to the above correction method is equal to 3, then 3 gears need to be adjusted upward on the basis of gear 2, that is, gear 5 is the optimal bias gear of the pixel. Another example, when the first-frame bias gear adjustment parameter of a pixel is set to gear 0 and the second-frame bias gear adjustment parameter of the pixel is set to gear 5, and the correction parameter C obtained according to the above correction method is equal to -2, then 2 gears need to be adjusted downward on the basis of gear 5, that is, gear 3 is the optimal bias gear of the pixel.

[0037] In the above embodiments, the calculated correction parameter C may be a non-integer. In this case, it can be rounded according to the rounding principle.

[0038] In some embodiments, the correction method may further include: Adjusting the second-frame bias gear adjustment parameter by the obtained correction parameter to form an updated bias gear adjustment parameter, where the updated bias gear adjustment parameter includes bias gear adjustment sub-parameters corresponding to each pixel; Sending the updated bias gear adjustment parameter to the pixel array to control each pixel of the pixel array to be in a third driving state; In the third driving state, the pixel array performs signal detection and obtains subsequent one or more frames of image data.

[0039] Since the bias gears of each pixel have been corrected by the corresponding correction parameters, the image data obtained in the third driving state is equal to or close to the correction target value.

[0040] An embodiment of the present application further provides a correction circuit module, which is applied to the readout circuit of a focal plane array detector, as Figure 2 shown, and in combination with Figure 1 if necessary, the correction circuit module is used to correct the pixel driving state of the pixel array. The pixel array is used to receive external signal radiation and can form a focal plane array detector with the correction circuit module.

[0041] The calibration circuit module includes a driving configuration circuit, a framing control circuit, a parameter operation circuit, a memory, and a central control circuit. The driving configuration circuit is used to refresh the driving configuration parameters of each pixel in the pixel array and control the driving state of the pixel. The framing control circuit is used to receive the data generated by the pixel array and integrate it into a valid DVP timing. The parameter operation circuit is used to complete parameter operations and enable control for data writing to and reading from the memory. The central control circuit is used to control the driving configuration circuit and the parameter operation circuit. The focal plane array detector has a pixel driving state calibration mode. In the pixel driving state calibration mode, the central control circuit controls the driving configuration circuit to send a first-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a first driving state. Among them, the first-frame bias level adjustment parameter includes the bias level adjustment parameter of each pixel. In the first driving state, the pixel array inputs corresponding first-frame image data. The central control circuit controls the driving configuration circuit to send a second-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a second driving state. Among them, the second-frame bias level adjustment parameter includes the bias level adjustment parameter of each pixel. In the second driving state, the pixel array inputs corresponding second-frame image data. Under the control of the central control circuit, the parameter operation circuit obtains the calibration parameter of the pixel array driving state according to the difference between the calibration target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data. Among them, the calibration parameter includes a plurality of sub-calibration parameters, and each sub-calibration parameter corresponds to each pixel of the pixel array one by one.

[0042] For the detector in the above embodiment, regardless of the number of bias adjustment levels, it can obtain the optimal calibration parameter within two frames, and thus can meet the requirement of high-efficiency and fast image output after the detector is powered on.

[0043] In the above embodiment, the bias level adjustment parameters of each pixel included in the first-frame bias level adjustment parameter can be all the same or not completely the same. That is, in the first-frame bias level adjustment parameter, the bias level adjustment parameters of each pixel can be set independently of each other. Taking an array detector with 32 bias adjustment levels (the 32 levels included are the 0th level, the 1st level, the 2nd level,..., the 29th level, the 30th level, and the 31st level) as an example, each pixel can be set to different levels or the same level. In the first-frame bias level adjustment parameter, the set value of the bias level adjustment parameter of each pixel does not affect or hardly affects the final calibration result. In one embodiment, the bias level adjustment parameters of each pixel can all be set to the 0th level.

[0044] In the above embodiments, the first frame of image data includes the gray scale values of each pixel. That is, in the first frame of image data input from the pixel array to the readout circuit, the gray scale values of each pixel in the first driving state are included.

[0045] In the above embodiments, the bias level adjustment parameters of each pixel included in the second frame bias level adjustment parameters may all be the same or may not be completely the same. That is, in the second frame bias level adjustment parameters, the bias level adjustment parameters of each pixel can be set independently of each other. Taking an array detector with 32 bias adjustment levels (the 32 levels included are level 0, level 1, level 2,..., level 29, level 30, and level 31) as an example, in the second frame bias level adjustment parameters, each pixel can be set to different levels or can be set to the same level. Similarly, in the second frame bias level adjustment parameters, the set values of the bias level adjustment parameters of each pixel do not affect or hardly affect the final calibration result. In one embodiment, in the second frame bias level adjustment parameters, the bias level adjustment parameters of each pixel can all be set to level 1 or all be set to level 2.

[0046] In the above embodiments, the second frame of image data includes the gray scale values of each pixel. That is, in the second frame of image data input from the pixel array to the readout circuit, the gray scale values of each pixel in the second driving state are included.

[0047] In the above embodiments, the calibration target value corresponds to the gray scale value of the image, which can be set or selected according to user requirements, such as 8000. Generally speaking, for each pixel in the pixel array, their calibration target values are usually the same, such as all being 8000. The "difference between the calibration target value and the second frame of image data" mentioned in the text refers to the difference between the calibration target value and the corresponding gray scale value of the second frame of image. For each pixel, the difference between the calibration target value and the corresponding gray scale value of its second frame of image may not be equal. The "difference between the second frame of image data and the first frame of image data" mentioned in the text refers to the difference between the corresponding gray scale value of the second frame of image and the corresponding gray scale value of the first frame of image. For each pixel, the difference between the corresponding gray scale value of its second frame of image and the corresponding gray scale value of its first frame of image may not be equal.

[0048] In some embodiments, the parameter operation circuit compensates the division operation by addition operation to obtain the calibration parameter of the driving state of the pixel array. For example, the parameter operation circuit obtains the optimal calibration parameter by performing the operation of C = [A+(B / 2N)] / (B / N) to ensure the accuracy of the calibration parameter; Wherein, A is the difference between the calibration target value and the second frame image data, B is the difference between the second frame image data and the first frame image data, N is the gear difference between the bias gear corresponding to the second frame bias gear adjustment parameter and the bias gear corresponding to the first frame bias gear adjustment parameter, and C is the obtained calibration parameter.

[0049] When the bias gear corresponding to the second frame bias gear adjustment parameter is adjacent to the bias gear corresponding to the first frame bias gear adjustment parameter, the value of N can be 1 or -1. For example, when the bias gear adjustment parameter of the first frame of a pixel is set to the 0th gear and the bias gear adjustment parameter of the second frame of the same pixel is set to the 1st gear, the corresponding gear difference N is equal to 1. Correspondingly, the calibration parameter is obtained by performing the operation of C = (A + B / 2) / B. When the value of N is 1, the amount of calculation can be reduced and the calibration speed can be further accelerated. Another example is that when the bias gear adjustment parameter of the first frame of a pixel is set to the 31st gear and the bias gear adjustment parameter of the second frame of the same pixel is set to the 30th gear, the corresponding gear difference N is equal to -1. When the value of N is -1, the amount of calculation can be reduced and the calibration speed can be further accelerated.

[0050] When the bias gear corresponding to the second frame bias gear adjustment parameter is not adjacent to the bias gear corresponding to the first frame bias gear adjustment parameter, the value of N is an integer greater than 1 or less than -1. For example, when the bias gear adjustment parameter of the first frame of a pixel is set to the 0th gear and the bias gear adjustment parameter of the second frame of the same pixel is set to the 2nd gear, the corresponding gear difference N is equal to 2. Another example is that when the bias gear adjustment parameter of the first frame of a pixel is set to the 31st gear and the bias gear adjustment parameter of the second frame of the same pixel is set to the 29th gear, the corresponding gear difference N is equal to -2.

[0051] In the above embodiments, the calibration parameter C corresponds to the gear value that each pixel needs to be further adjusted based on the second-frame bias gear adjustment parameter. For a pixel, when the calculated C value is equal to 0, the second-frame bias gear where the pixel is currently located is its optimal bias gear; when the calculated C value is equal to 1, the second-frame bias gear of the pixel needs to be adjusted upward by one gear; when the calculated C value is equal to N, the second-frame bias gear of the pixel needs to be adjusted upward by N gears. For example, when the first-frame bias gear adjustment parameter of a pixel is set to the 0th gear and the second-frame bias gear adjustment parameter of the pixel is set to the 2nd gear, and the calibration parameter C obtained according to the above calibration method is equal to 3, then 3 gears need to be adjusted upward based on the 2nd gear, that is, the 5th gear is the optimal bias gear of the pixel. Another example, when the first-frame bias gear adjustment parameter of a pixel is set to the 0th gear and the second-frame bias gear adjustment parameter of the pixel is set to the 5th gear, and the calibration parameter C obtained according to the above calibration method is equal to -2, then 2 gears need to be adjusted downward based on the 5th gear, that is, the 3rd gear is the optimal bias gear of the pixel.

[0052] In the above embodiments, the calculated calibration parameter C may be a non-integer. In this case, it can be rounded according to the principle of rounding.

[0053] In some embodiments, the parameter operation circuit forms updated bias gear adjustment parameters according to the obtained calibration parameter and the second-frame bias gear adjustment parameter, where the updated bias gear adjustment parameters include bias gear adjustment sub-parameters corresponding to each pixel; the central control circuit controls the drive configuration circuit to send the updated bias gear adjustment parameters to the pixel array to control each pixel of the pixel array to be in the third drive state; in the third drive state, the pixel array performs signal detection and obtains subsequent one or more frames of image data.

[0054] Since the bias gears of each pixel have been corrected by the corresponding calibration parameters, the image data obtained in the third drive state is equal to or close to the calibration target value.

[0055] In some embodiments, in the pixel drive state calibration mode, the central control circuit also controls the parameter operation circuit to write the first-frame image data into the memory.

[0056] In some embodiments, in the pixel drive state calibration mode, the central control circuit also controls the parameter operation circuit to write the second-frame image data into the memory.

[0057] In some embodiments, the focal plane array detector further includes a readout circuit for collecting data generated by pixels and realizing amplified output; The calibration circuit module is integrated into the readout circuit.

[0058] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the scope of protection of this application.

Claims

1. A method for correcting the driving state of a pixel array, characterized in that, The calibration method is applied to the readout circuit of a focal plane array detector for calibrating the pixel driving states of the pixel array in the focal plane array detector. The calibration method includes: Sending a first-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a first driving state, where the first-frame bias level adjustment parameter includes the bias level adjustment parameter for each pixel; With the pixel array in the first driving state, the pixel array inputs first-frame image data; Sending a second-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a second driving state, where the second-frame bias level adjustment parameter includes the bias level adjustment parameter for each pixel; With the pixel array in the second driving state, the pixel array inputs second-frame image data; Based on the difference between the calibration target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data, obtaining the calibration parameter for the driving state of the pixel array, where the calibration parameter includes a plurality of sub-calibration parameters, and each sub-calibration parameter corresponds one-to-one to each pixel of the pixel array.

2. The calibration method according to claim 1, wherein Compensating the division operation by addition operation to obtain the calibration parameter for the driving state of the pixel array.

3. The calibration method according to claim 2, wherein Using a circuit to perform the operation of C = [A+(B / 2N)] / (B / N) to obtain the calibration parameter: where A is the difference between the calibration target value and the second-frame image data, B is the difference between the second-frame image data and the first-frame image data, N is the level difference between the bias level corresponding to the second-frame bias level adjustment parameter and the bias level corresponding to the first-frame bias level adjustment parameter, and C is the obtained calibration parameter.

4. The calibration method according to claim 3, wherein The bias level corresponding to the second-frame bias level adjustment parameter is adjacent to the bias level corresponding to the first-frame bias level adjustment parameter, and N is set to 1. The operation of C = (A + B / 2) / B is performed to obtain the calibration parameter.

5. The calibration method according to claim 1, wherein The calibration method further includes: Adjusting the second-frame bias level adjustment parameter by the obtained calibration parameter to form an updated bias level adjustment parameter, where the updated bias level adjustment parameter includes the bias level adjustment sub-parameters corresponding to each pixel; Sending the updated bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a third driving state; With the pixel array in the third driving state, the pixel array performs signal detection and obtains one or more subsequent frames of image data.

6. A calibration circuit module is applied to the readout circuit of a focal plane array detector and is used to calibrate the pixel driving state of the pixel array in the focal plane array detector. It is characterized in that The calibration circuit module includes a driving configuration circuit, a framing control circuit, a parameter operation circuit, a memory, and a central control circuit. The driving configuration circuit is used to refresh the driving configuration parameters of each pixel in the pixel array and control the driving state of the pixel; the framing control circuit is used to receive the data generated by the pixel array and integrate it into a valid DVP timing; the parameter operation circuit is used to complete parameter operations and is used for enabling control of data writing to the memory and reading from the memory; the central control circuit is used to control the driving configuration circuit and the parameter operation circuit; The focal plane array detector has a pixel driving state correction mode. In the pixel driving state correction mode, the central control circuit controls the driving configuration circuit to send a first-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a first driving state. Wherein, the first-frame bias level adjustment parameter includes the bias level adjustment parameter of each pixel; in the first driving state, the pixel array inputs first-frame image data; the central control circuit controls the driving configuration circuit to send a second-frame bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a second driving state. Wherein, the second-frame bias level adjustment parameter includes the bias level adjustment parameter of each pixel; in the second driving state, the pixel array inputs second-frame image data; under the control of the central control circuit, the parameter operation circuit obtains the correction parameter of the pixel array driving state according to the difference between the correction target value and the second-frame image data, and the difference between the second-frame image data and the first-frame image data. Wherein, the correction parameter includes a plurality of sub-correction parameters, and each sub-correction parameter corresponds to each pixel of the pixel array one by one.

7. The calibration circuit module according to claim 6, wherein The parameter operation circuit compensates the division operation by addition operation to obtain the correction parameter of the pixel array driving state.

8. The calibration circuit module according to claim 7, wherein The parameter operation circuit obtains the correction parameter by performing the operation of C = [A+(B / 2N)] / (B / N), where A is the difference between the correction target value and the second-frame image data, B is the difference between the second-frame image data and the first-frame image data, N is the level difference between the bias level corresponding to the second-frame bias level adjustment parameter and the bias level corresponding to the first-frame bias level adjustment parameter, and C is the obtained correction parameter.

9. The calibration circuit module according to claim 8, wherein The bias level corresponding to the second-frame bias level adjustment parameter is adjacent to the bias level corresponding to the first-frame bias level adjustment parameter, and the value of N is 1. The correction parameter is obtained by performing the operation of C = (A + B / 2) / B.

10. The calibration circuit module according to claim 6, wherein, The parameter operation circuit forms an updated bias level adjustment parameter according to the obtained correction parameter and the second-frame bias level adjustment parameter. Wherein, the updated bias level adjustment parameter includes the bias level adjustment sub-parameters corresponding to each pixel; the central control circuit controls the driving configuration circuit to send the updated bias level adjustment parameter to the pixel array to control each pixel of the pixel array to be in a third driving state; in the third driving state, the pixel array inputs the subsequent one frame or multiple frames of image data.

11. The calibration circuit module according to claim 6, wherein In the pixel driving state correction mode, the central control circuit also controls the parameter operation circuit to write the first-frame image data into the memory.

12. The calibration circuit module according to claim 6, wherein In the pixel driving state correction mode, the central control circuit also controls the parameter operation circuit to write the second-frame image data into the memory.

13. The calibration circuit module according to claim 6, wherein The correction circuit module is integrated in the readout circuit.

Images