Infrared detector protection method and device

Abstract

The present invention discloses an infrared detector protection method and device. For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is obtained according to the output signal of the sensor element of the pixel. If the temperature collected by the sensor element of the pixel is greater than the first preset temperature, the temperature gain of the sensor element of the pixel is reduced so that the sensor element of the pixel can continue to collect temperature. The first preset temperature is lower than the burn temperature of the sensor element of the infrared detector. When the sensor element of the infrared detector collects a temperature greater than the first preset temperature, the temperature gain of the sensor element is reduced so that the sensor element of the pixel can continue to collect temperature. Then, the infrared detector can detect the output temperature for a temperature greater than the first preset temperature but less than the burn temperature, and can more accurately judge whether the detected temperature reaches the burn temperature of the sensor element of the infrared detector, which helps to more accurately protect the infrared detector from being burned and damaged by high-temperature targets.

Description

Technical Field

[0001] The present invention relates to the field of infrared detection devices, and in particular to an infrared detector protection method and device. Background Art

[0002] Infrared imaging was first used in the military and is now widely used in military, industrial and civilian fields. Infrared imaging is the process of detecting the energy radiated by an object through an infrared sensor array to form an infrared image of the object.

[0003] Infrared sensor materials mainly use vanadium oxide (VOX) or amorphous silicon. When these materials detect ultra-high temperature objects such as the sun, the sensors will be damaged, causing damage to the detection device. The signals collected by the damaged sensor units are distorted, which will eventually cause bad pixels or spots in the image, affecting the imaging quality.

[0004] In the prior art, some infrared detectors do not output a response to high-temperature energy exceeding a certain temperature range in order to obtain good image effects and prevent the sensor unit from being damaged. However, this high-temperature energy may not reach a temperature that causes burns to the sensor unit, which leads to over-protection. Summary of the invention

[0005] The purpose of the present invention is to provide an infrared detector protection method and device, which are helpful to more accurately protect the infrared detector from being burned and damaged by a high-temperature target.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for protecting an infrared detector, comprising:

[0008] For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is obtained according to the output signal of the sensor element of the pixel;

[0009] For any pixel of the infrared detector, if the temperature collected by the sensor element of this pixel is greater than the first preset temperature, the temperature gain of the sensor element of this pixel is reduced so that the sensor element of this pixel continues to collect temperature; wherein the temperature gain of the sensor element of any pixel is the change in the output signal value of the sensor element of this pixel when the temperature collected by the sensor element of this pixel changes by unit temperature, and the first preset temperature is lower than the burning temperature of the sensor element of the infrared detector.

[0010] Preferably, reducing the temperature gain of the sensor element of the pixel includes: adjusting the input power of the sensor element of the pixel of the infrared detector to reduce the temperature gain of the sensor element of the pixel.

[0011] Preferably, for any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is divided into at least two temperature intervals, the at least two temperature intervals include a first temperature interval, the first temperature interval is less than or equal to the first preset temperature, and the temperature gain of the sensor element of the pixel corresponding to each temperature interval is different;

[0012] The method also includes: for any pixel of the infrared detector, determining the temperature interval to which the temperature collected by the sensor element of the pixel belongs, and controlling the temperature gain of the sensor element of the pixel to be consistent with the temperature gain corresponding to the temperature interval to which the temperature collected by the sensor element of the pixel belongs.

[0013] Preferably, for a temperature range less than or equal to the first preset temperature, the encoding range of the output signal value of the sensor element of the infrared detector pixel is [0,2 N -M], for a temperature range greater than the first preset temperature and less than or equal to the burning temperature of the infrared detector sensor element, the encoding range of the output signal value of the sensor element of the infrared detector pixel is (2 N -M,2 N -1], M and N are positive integers greater than zero.

[0014] Preferably, it also includes: for any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to a second preset temperature, protective measures are performed on the infrared detector so that the temperature collected by the sensor element of each pixel of the infrared detector is less than the second preset temperature; wherein the second preset temperature is greater than the first preset temperature and less than or equal to the burning temperature of the sensor element of the infrared detector.

[0015] Preferably, the protective measures for the infrared detector include: blocking light from entering the infrared detector or controlling to reduce the aperture, the aperture being used to control the amount of light energy incident on the infrared detector;

[0016] Controls for stopping down the aperture include:

[0017] Calculating the temperature attenuation coefficient of the highest temperature among the temperatures collected by the sensing elements of each pixel of the infrared detector relative to the second preset temperature;

[0018] The aperture size is controlled so that the aperture size corresponds to the aperture value corresponding to the temperature attenuation coefficient.

[0019] Preferably, it also includes:

[0020] For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to a second preset temperature, the position of the high-temperature target in the image collected by the infrared detector is obtained; wherein the second preset temperature is greater than the first preset temperature and less than or equal to the burning temperature of the sensor element of the infrared detector;

[0021] When the angle of the lens corresponding to the infrared detector changes, the angle change of the high-temperature target relative to the center of the image in the image collected by the infrared detector is obtained based on the relationship between the angle change of the object relative to the optical axis of the lens corresponding to the infrared detector and the angle change of the object image relative to the center of the image in the image collected by the infrared detector, as well as the angle change of the lens corresponding to the infrared detector, so as to judge whether the high-temperature target deviates from the field of view of the lens corresponding to the infrared detector.

[0022] Preferably, if it is determined that the high-temperature target has deviated from the field of view of the lens corresponding to the infrared detector, the protection measures for the infrared detector are cancelled.

[0023] Preferably, the method further includes: if it is determined based on the angular change of the high-temperature target relative to the center of the image captured by the infrared detector that the high-temperature target will enter the field of view of the lens corresponding to the infrared detector again, a prompt is issued.

[0024] An infrared detector protection device is used to execute the infrared detector protection method mentioned above.

[0025] It can be seen from the above technical scheme that the infrared detector protection method and device provided by the present invention, for any pixel of the infrared detector, obtains the temperature collected by the sensor element of this pixel according to the output signal of the sensor element of this pixel. If the temperature collected by the sensor element of this pixel is greater than the first preset temperature, the temperature gain of the sensor element of this pixel is reduced so that the sensor element of this pixel can continue to collect temperature.

[0026] The first preset temperature is lower than the burning temperature of the infrared detector sensor element. When the infrared detector sensor element collects a temperature higher than the first preset temperature, the temperature gain of the sensor element is reduced so that the sensor element can continue to collect temperature. Then, the infrared detector can detect the output temperature for a temperature higher than the first preset temperature but lower than the burning temperature of the infrared detector sensor element, so that it can be judged whether the burning temperature of the infrared detector sensor element is reached according to the temperature detected by the infrared detector. It can more accurately judge whether the detected temperature reaches the burning temperature of the infrared detector sensor element, which helps to more accurately protect the infrared detector from being burned and damaged by high-temperature targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A flowchart of an infrared detector protection method provided by an embodiment of the present invention;

[0029] Figure 2 A schematic circuit diagram of a sensing element of any pixel of an infrared detector according to a specific example of the present invention;

[0030] Figure 3 is the relationship between the output signal value of the infrared detector sensor element and the temperature collected by the sensor element in the embodiment of the present invention;

[0031] Figure 4 A flowchart of an infrared detector protection method provided by another embodiment of the present invention;

[0032] Figure 5 A schematic diagram of an infrared detector and a corresponding lens provided by an embodiment of the present invention;

[0033] Figure 6 A schematic diagram of an infrared detector and a corresponding lens provided in yet another embodiment of the present invention;

[0034] Figure 7 A schematic diagram of an infrared detector and a corresponding lens provided in yet another embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0036] Please refer to Figure 1 , Figure 1 A flowchart of an infrared detector protection method provided in this embodiment is shown in the figure. The infrared detector protection method includes the following steps:

[0037] S10: For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is obtained according to the output signal of the sensor element of the pixel.

[0038] The infrared detector includes a sensor element array, and the sensor element of each pixel of the infrared detector collects temperature and generates an output signal accordingly. The image collected by the infrared detector can be obtained according to the output signal of each pixel of the infrared detector. Each pixel of the infrared detector may include one sensor element, or each pixel of the infrared detector may include multiple sensor elements to collect temperature, which is not specifically limited in this embodiment.

[0039] For any pixel of the infrared detector, the output signal of the sensor element of the pixel is quantified, and the temperature collected by the sensor element of the pixel is obtained according to the output signal of the pixel.

[0040] S11: For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than the first preset temperature, the temperature gain of the sensor element of the pixel is reduced so that the sensor element of the pixel continues to collect temperature.

[0041] The temperature gain of the sensor element of any pixel is the change in the output signal value of the sensor element of the pixel when the temperature collected by the sensor element of the pixel changes by a unit temperature.

[0042] The first preset temperature is lower than the burning temperature of the infrared detector sensor element. The range less than or equal to the first preset temperature can be corresponded to the temperature range corresponding to normal imaging of the infrared detector sensor element. For any pixel of the infrared detector, if the temperature collected by the sensor element of this pixel is greater than the first preset temperature, that is, the sensor element of the infrared detector collects a temperature that exceeds the temperature range of normal imaging, then the temperature gain of the sensor element of this pixel is reduced, so that the sensor element of this pixel can continue to collect temperature, can continue to output signals, and output temperature values ​​by quantizing the output signals.

[0043] In this embodiment, the specific value of the first preset temperature is not limited. In practical applications, the specific value of the first preset temperature can be set according to the material of the infrared detector sensor element, the detection temperature range or the temperature detection requirements in practical applications.

[0044] In the infrared detector protection method of this embodiment, the first preset temperature is lower than the burning temperature of the infrared detector sensor element. Then, when the infrared detector sensor element collects a temperature higher than the first preset temperature, the temperature gain of the sensor element is reduced so that the sensor element can continue to collect temperature. Then, the infrared detector can detect the output temperature for a temperature higher than the first preset temperature but lower than the burning temperature of the infrared detector sensor element, so that it can be judged whether the burning temperature of the infrared detector sensor element is reached according to the temperature detected by the infrared detector, and it can be judged more accurately whether the detected temperature reaches the burning temperature of the infrared detector sensor element, which helps to more accurately protect the infrared detector from being burned and damaged by high-temperature targets.

[0045] The sensor element of any pixel of the infrared detector is connected in the circuit, and by inputting electricity into the sensor element, the sensor element generates an output signal when it collects temperature. Optionally, a voltage can be applied to the sensor element or a current can be input into the sensor element so that the sensor element can generate an output signal when it collects temperature.

[0046] Exemplary references Figure 2 , Figure 2 The circuit diagram of the sensing element of any pixel of an infrared detector of a specific example is shown in the figure. The circuit includes a reference resistor R connected in series in sequence. ref , the first field effect tube, the second field effect tube and the sensing element R act , the gate of the first field effect tube is connected to the first input voltage V 1 , the gate of the second field effect tube is connected to the second input voltage V 2 The source of the first field effect tube and the drain of the second field effect tube are connected and used as the output terminal. The output signal Vout of the output terminal is input to the analog-to-digital converter ADC, and the code value CODE is output after analog-to-digital conversion. The sensor element R is obtained according to the output code value. act The collected temperature. Optionally, the output signal of the infrared detector can be encoded using N-bit binary numbers in the encoding range of [0,2 N -1].

[0047] Optionally, reducing the temperature gain of the sensor element of the infrared detector pixel may include: adjusting the input power of the sensor element of the infrared detector pixel to reduce the temperature gain of the sensor element of the pixel. For example, the voltage applied to the sensor element may be adjusted or the current input to the sensor element may be adjusted.

[0048] correspond Figure 2 The sensing element circuit shown can be operated by changing the first input voltage V 1 , the second input voltage V 2The size of can be adjusted to achieve the purpose of adjusting the temperature gain of the sensor element. Figure 2 As shown, the first input voltage V is controlled by the first resistor string 1 The first resistor string includes n resistors R connected in series. 1 ~R n , where by changing the first resistor string in series to the first input voltage V 1 The number of resistors in the circuit (i.e., the number of resistors marked OUT in the first resistor string in the figure) controls the first input voltage V 1 The second input voltage V is controlled by the second resistor string. 2 The second resistor string includes m resistors R 1 ~R m , where by changing the second resistor string in series to the second input voltage V 2 The number of resistors in the circuit (i.e., the number of resistors marked OUT in the second resistor string in the figure) can control the second input voltage V 2 size.

[0049] In the method of this embodiment, when the temperature collected by the infrared detector sensor element is greater than the first preset temperature, the temperature gain of the sensor element is reduced, so that the infrared detector can continue to detect and output temperature values ​​in the temperature range exceeding the first preset temperature. Compared with the existing method that can only detect the temperature range of normal imaging of the infrared detector, this method expands the temperature range of the infrared detector's quantitative output.

[0050] Optionally, for a temperature range less than or equal to the first preset temperature, the encoding range of the output signal value of the sensor element of the infrared detector pixel is [0,2 N -M], for a temperature range greater than the first preset temperature and less than or equal to the burning temperature of the infrared detector sensor element, the encoding range of the output signal value of the sensor element of the infrared detector pixel is (2 N -M,2 N -1], M and N are positive integers greater than zero.

[0051] Exemplary references Figure 3 , Figure 3 is the relationship between the code CODE of the output signal value of the infrared detector sensor element in this embodiment and the temperature collected by the sensor element. In the figure, T 0 ~T 1 is the temperature range of normal imaging of the detector, T 5 Indicates the burning temperature of the detector sensor element, such as the temperature of the sun, T 1 ~T 4 For some temperature point in the middle. You can choose T 1is the first preset temperature, for the temperature range [T 0 , T 1 ], the encoding range of the output signal value of the sensor element of the infrared detector pixel is [0,2 N -M]; for the temperature range (T 1 , T 5 ], the encoding range of the output signal value of the sensor element of the infrared detector pixel is (2 N -M,2 N -1].

[0052] correspond Figure 2 The sensor element circuit shown in the figure determines whether the code value CODE output by the analog-to-digital converter ADC is greater than 2 N -M, to determine the sensor element R act Is the collected temperature greater than the first preset temperature? If so, it means that the sensor element R act If the collected temperature is greater than the first preset temperature, the sensor element R is reduced. act The temperature gain is specifically increased by the first input voltage V 1 , reduce the second input voltage V 2 , thereby reducing Vout as the sensing element R act The amplitude changes with changes, thereby reducing the temperature gain.

[0053] Preferably, for any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is divided into at least two temperature intervals, the at least two temperature intervals include a first temperature interval, the first temperature interval is less than or equal to the first preset temperature, and the temperature gain of the sensor element of the pixel corresponding to each of the temperature intervals is different. Accordingly, the method further includes: for any pixel of the infrared detector, determining the temperature interval to which the temperature collected by the sensor element of the pixel belongs, and controlling the temperature gain of the sensor element of the pixel to be consistent with the temperature gain corresponding to the temperature interval to which the temperature collected by the sensor element of the pixel belongs.

[0054] Optionally, the temperature collected by the sensor element of any pixel can be divided into two temperature intervals, including a first temperature interval and a second temperature interval, the first temperature interval is less than or equal to the first preset temperature, the second temperature interval is greater than the first preset temperature and less than or equal to the burn temperature of the sensor element, the temperature gain of the pixel sensor element corresponding to the first temperature interval and the second temperature interval is different, and the temperature gain corresponding to the second temperature interval is less than the temperature gain corresponding to the first temperature interval. If the temperature collected by the sensor element of the pixel is greater than the first preset temperature and is within the second temperature interval, the temperature gain of the sensor element of the pixel is controlled to be the temperature gain corresponding to the second temperature interval. If the temperature collected by the sensor element of the pixel returns to the first temperature interval, that is, less than or equal to the first preset temperature, the temperature gain of the sensor element of the pixel is controlled to be restored to the temperature gain corresponding to the first temperature interval.

[0055] Optional, corresponding to Figure 3 As shown, the temperature collected by the sensor element of any pixel can be divided into five temperature intervals, including the temperature interval [T 0 , T 1 ]、(T 1 , T 2 ]、(T 2 , T 3 ]、(T 3 , T 4 ] and (T 4 , T 5 ], each temperature interval corresponds to a different temperature gain. The temperature gain of the sensor element of the pixel is controlled to be the temperature gain corresponding to the temperature interval to which the temperature collected belongs, depending on the temperature interval to which the temperature collected belongs.

[0056] In this embodiment, there is no specific limitation on the number of temperature intervals into which the temperature collected by the sensor element of any pixel is divided, that is, the number of levels of the temperature gain of the sensor element. In practical applications, it can be set according to the specific situation or application requirements of the infrared detector.

[0057] Please refer to Figure 4 , Figure 4 A flowchart of an infrared detector protection method provided in another embodiment is shown in the figure. The infrared detector protection method includes the following steps:

[0058] S20: For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is obtained according to the output signal of the sensor element of the pixel.

[0059] The implementation method of the sensor element of the infrared detector pixel generating an output signal and obtaining the collected temperature according to the output signal can refer to the corresponding description in the above embodiment, which will not be repeated here.

[0060] S21: for any pixel of the infrared detector, determine whether the temperature collected by the sensor element of the pixel is greater than a first preset temperature. If yes, proceed to step S22; if no, proceed to step S20.

[0061] S22: reducing the temperature gain of the sensor element of the pixel so that the sensor element of the pixel continues to collect temperature, and proceeding to step S23.

[0062] The implementation method of reducing the temperature gain of the sensor element of the pixel so that the sensor element of the pixel can continue to collect temperature can refer to the corresponding description in the above embodiment, which will not be repeated here.

[0063] S23: For any pixel of the infrared detector, determine whether the temperature collected by the sensor element of the pixel is greater than or equal to the second preset temperature. If yes, proceed to step S24; if no, proceed to step S20.

[0064] S24: Executing protection measures on the infrared detector so that the temperature collected by the sensor element of each pixel of the infrared detector is less than the second preset temperature.

[0065] The second preset temperature can be set to be greater than the first preset temperature and less than or equal to the burning temperature of the infrared detector sensor element. When the temperature collected by the infrared detector sensor element is greater than or equal to the second preset temperature, the infrared detector is protected so that the temperature collected by the sensor element of each pixel of the infrared detector is less than the second preset temperature, so as to avoid the infrared detector sensor element detecting a temperature greater than or equal to the burning temperature, which may cause the infrared detector sensor element to be burned and damaged, thereby protecting the infrared detector. Figure 3 As shown, it can be obtained from T 1 ~T 5 Select a temperature between 1 and 2 as the second preset temperature. You can set T 5 is the second preset temperature, or select a temperature slightly lower than T 5 The temperature is taken as the second preset temperature, for example, the range of the second preset temperature is 80%T 5 ~T 5 When the temperature collected by the sensor element reaches its burning temperature, the sensor element will not be damaged in a short time. Therefore, in this method, when it is monitored that the temperature collected by the sensor element is greater than or equal to the second preset temperature, protective measures are performed on the infrared detector to prevent the sensor element from collecting a temperature greater than or equal to the second preset temperature for a long time.

[0066] In the infrared detector protection method of this embodiment, the infrared detector can detect the output temperature for a temperature greater than the first preset temperature but less than the burning temperature of the infrared detector sensor element, so that it is possible to judge whether the burning temperature of the infrared detector sensor element is reached according to the temperature detected by the infrared detector, and it is possible to more accurately judge whether the detected temperature reaches the burning temperature of the infrared detector sensor element, which helps to more accurately protect the infrared detector from being burned and damaged by high-temperature targets. The second preset temperature is greater than the first preset temperature and less than or equal to the burning temperature of the infrared detector sensor element. When the temperature collected by the infrared detector sensor element is greater than or equal to the second preset temperature, the infrared detector is protected. Measures are taken to prevent the infrared detector sensor element from collecting a temperature greater than or equal to the burning temperature of the sensor element, thereby achieving a more accurate protection function for the infrared detector.

[0067] Optionally, executing the protection measure for the infrared detector may include: controlling to reduce the aperture, the aperture being used to control the amount of light energy incident on the infrared detector. When the temperature collected by the sensor element of any pixel of the infrared detector is greater than or equal to the second preset temperature, the aperture may be controlled to reduce so that the light energy incident on the infrared detector is reduced, thereby preventing the high temperature energy from continuing to radiate to the infrared detector and causing damage to the infrared detector.

[0068] Optionally, the aperture can be reduced by the following method, including the following steps:

[0069] S31: Calculate the temperature attenuation coefficient of the highest temperature among the temperatures collected by the sensor elements of each pixel of the infrared detector relative to the second preset temperature.

[0070] Assuming that the highest temperature among the temperatures collected by the sensor elements of each pixel of the infrared detector is A, and the second preset temperature is B, the temperature attenuation coefficient K is calculated according to the temperature A and the temperature B, for example, K=B / A.

[0071] S32: Control the aperture size so that the aperture size corresponds to the aperture value corresponding to the temperature attenuation coefficient.

[0072] A table of aperture value and temperature attenuation coefficient, namely, an "aperture value F-temperature attenuation coefficient K" lookup table is pre-stored, in which each temperature attenuation coefficient and the corresponding aperture value are recorded. According to the calculated temperature attenuation coefficient, the aperture value F corresponding to the currently calculated temperature attenuation coefficient is looked up from the table, and then the aperture size is controlled to adjust the aperture to the size corresponding to the aperture value F.

[0073] Optional, for reference Figure 5 As shown, Figure 5The schematic diagram of an infrared detector and a corresponding lens provided in an embodiment is as follows. The aperture 102 can be set between the lens 101 and the infrared detector 100. By controlling the size of the aperture 102, the amount of light energy incident on the infrared detector 100 can be controlled. Figure 6 As shown, Figure 6 A schematic diagram of an infrared detector and a corresponding lens provided in another embodiment, wherein an aperture 102 may be disposed between two lenses of the lens 101, and the amount of light energy incident on the infrared detector 100 may be controlled by controlling the size of the aperture 102. Optionally, the aperture 102 may be an electrically adjustable aperture.

[0074] Optionally, the protective measures for the infrared detector may include: blocking light from entering the infrared detector. When the temperature collected by the sensor element of any pixel of the infrared detector is greater than or equal to the second preset temperature, light may be blocked from entering the infrared detector, for example, by using a baffle to block the light from passing through, thereby preventing high temperature energy from continuing to radiate to the infrared detector and causing damage. Figure 7 , Figure 7 A schematic diagram of an infrared detector and a corresponding lens provided in yet another embodiment, wherein a baffle 103 may be provided between the lens 101 and the infrared detector 100 .

[0075] Further preferably, the infrared detector protection method of this embodiment further includes:

[0076] S25: For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to the second preset temperature, the position of the high-temperature target in the image collected by the infrared detector is obtained.

[0077] The high temperature target in the collected image refers to a target area formed by pixels in the collected image whose temperature collected by the sensor element is greater than or equal to the second preset temperature.

[0078] For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to the second preset temperature, the high temperature target is found in the image collected by the infrared detector at the current moment and the position of the high temperature target is determined. The position of the high temperature target can be represented by the central pixel position of the high temperature target.

[0079] S26: When the angle of the lens corresponding to the infrared detector changes, the angle change of the high-temperature target relative to the center of the image in the image collected by the infrared detector is obtained based on the relationship between the angle change of the object relative to the optical axis of the lens corresponding to the infrared detector and the angle change of the object image relative to the center of the image in the image collected by the infrared detector, as well as the angle change of the lens corresponding to the infrared detector, so as to determine whether the high-temperature target deviates from the field of view of the lens corresponding to the infrared detector.

[0080] When the temperature collected by the sensor element of any pixel of the infrared detector is greater than or equal to the second preset temperature, it indicates that the infrared detector has detected a high-temperature target. After the infrared detector detects the high-temperature target, the infrared detector and the corresponding lens may move, and the infrared detector corresponding lens changes direction, and the angle change amount of the infrared detector corresponding lens can be detected. Optionally, an inertial sensor can be used to detect the angle change amount of the infrared detector corresponding lens.

[0081] According to the angle change of the lens corresponding to the infrared detector, and according to the relationship between the angle change of the object relative to the optical axis of the lens corresponding to the infrared detector and the angle change of the object image relative to the center of the image in the image collected by the infrared detector, the angle change of the high-temperature target relative to the center of the image in the image collected by the infrared detector can be obtained.

[0082] Optionally, a three-dimensional rectangular coordinate system may be established with the optical axis of the lens corresponding to the infrared detector as the Z axis, the row direction of the image collected by the infrared detector as the X axis, and the column direction as the Y axis.

[0083] When the infrared detector detects a high-temperature target, an image is collected, all pixels of the high-temperature target in the image are obtained, and the coordinates of the center pixel of the high-temperature target are calculated as (x 0 ,y 0 ). Calculate the high temperature target center pixel (x 0 ,y 0 ) and the center of the lens are projected on the image plane, that is, on the focal plane of the infrared detector, and the angles θ between them and the X-axis and Y-axis respectively x and θ y .

[0084] By detecting the angle change of the infrared detector corresponding to the lens, the angle change of the infrared detector corresponding to the lens at any time compared to the angle change of the infrared detector corresponding to the lens when the high-temperature target is detected can be obtained. The angle change of the infrared detector corresponding to the lens in the X-axis direction, the Y-axis direction and the Z-axis direction can be detected. The angle change in the X-axis and Y-axis directions is recorded as Δθ x With Δθ y Using the inertial sensor, the angle changes of the lens corresponding to the infrared detector in the X-axis direction, the Y-axis direction and the Z-axis direction can be obtained according to the data measured by the inertial sensor.

[0085] For infrared detectors, the maximum angle between its boundary pixel and the center of the lens is calculated according to the following formula. The maximum angle in the X-axis direction is θ xmax , the maximum angle along the Y axis is θ ymax , where P is the total number of image rows, Q is the total number of image columns, d is the pixel pitch, and f is the focal length of the lens.

[0086] θ xmax =arctan(P*d / 2f);

[0087] θ ymax =arctan(Q*d / 2f);

[0088] At any time, calculate the result of the following formula. If it is true, the high temperature target is in the image, that is, the high temperature target is in the field of view of the infrared detector corresponding lens; otherwise, the high temperature target is not in the image, that is, the high temperature target is not in the field of view of the infrared detector corresponding lens. Where θ th is the protection threshold set based on experience:

[0089] (|θ x +Δθ x |+θ th ≤θ xmax )&&(|θ y +Δθ y |+θ th ≤θ ymax ).

[0090] If it is determined that the high temperature target has deviated from the field of view of the lens corresponding to the infrared detector, the protection measures for the infrared detector can be cancelled, such as restoring the aperture to a normal size or releasing the baffle.

[0091] Further preferably, if it is determined based on the angular change of the high-temperature target relative to the center of the image captured by the infrared detector that the high-temperature target will enter the field of view of the lens corresponding to the infrared detector again, a prompt is issued.

[0092] After the protection measures for the infrared detector are completed, the angle of the high-temperature target relative to the optical axis of the lens corresponding to the infrared detector can be continuously calculated. Based on the position of the high-temperature target in the image collected when the infrared detector detects the high-temperature target, and the change in the angle of the lens corresponding to the current infrared detector compared to the angle of the lens corresponding to the infrared detector when the high-temperature target is detected, assuming that the position of the high-temperature target remains unchanged, the angle of the current high-temperature target relative to the optical axis of the lens corresponding to the infrared detector can be calculated.

[0093] Before the edge of a high-temperature target is about to enter the field of view of the infrared detector's corresponding lens, a prompt can be issued to remind the user to avoid facing the high-temperature target, or to perform protective actions in advance to prevent the infrared detector from being burned. The judgment of the target edge lies in reasonably setting the empirical threshold θ of the target size. th For example, the size of the sun is fixed, and the threshold of its angle can be set manually.

[0094] Therefore, the infrared detector protection method of this embodiment, when the infrared detector detects a high-temperature target, monitors the position of the high-temperature target relative to the field of view of the lens corresponding to the infrared detector according to the angle change of the lens corresponding to the infrared detector, to monitor whether the high-temperature target deviates from the field of view of the lens corresponding to the infrared detector or is about to enter the field of view of the lens corresponding to the infrared detector, and takes corresponding measures to realize the protection function of the infrared detector.

[0095] Correspondingly, this embodiment also provides an infrared detector protection device for executing the infrared detector protection method described above.

[0096] The infrared detector protection device of this embodiment, for any pixel of the infrared detector, obtains the temperature collected by the sensor element of the pixel according to the output signal of the sensor element of the pixel. If the temperature collected by the sensor element of the pixel is greater than the first preset temperature, the temperature gain of the sensor element of the pixel is reduced so that the sensor element of the pixel can continue to collect temperature. The first preset temperature is lower than the burning temperature of the infrared detector sensor element. Then, when the infrared detector sensor element collects a temperature greater than the first preset temperature, the temperature gain of the sensor element is reduced so that the sensor element can continue to collect temperature. Then, the infrared detector can detect the output temperature for a temperature greater than the first preset temperature but less than the burning temperature of the infrared detector sensor element, so that it can be judged whether the burning temperature of the infrared detector sensor element is reached according to the temperature detected by the infrared detector, and it can be more accurately judged whether the detected temperature reaches the burning temperature of the infrared detector sensor element, which helps to more accurately protect the infrared detector from being burned and damaged by high-temperature targets.

[0097] The above is a detailed introduction to the infrared detector protection method and device provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for protecting an infrared detector, characterized in that: include: For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is obtained according to the output signal of the sensor element of the pixel; For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than the first preset temperature, the temperature gain of the sensor element of the pixel is reduced so that the sensor element of the pixel continues to collect temperature, continues to output signals, and outputs temperature values ​​by quantizing the output signals; wherein the temperature gain of the sensor element of any pixel is the amount of change in the output signal value of the sensor element of the pixel when the temperature collected by the sensor element of the pixel changes by a unit temperature, and the first preset temperature is less than the burning temperature of the sensor element of the infrared detector; For a temperature range less than or equal to the first preset temperature, the encoding range of the output signal value of the sensor element of the infrared detector pixel is [0,2 N -M], for a temperature range greater than the first preset temperature and less than or equal to the burning temperature of the infrared detector sensor element, the encoding range of the output signal value of the sensor element of the infrared detector pixel is (2 N -M,2 N -1], M and N are positive integers greater than zero, and the output code value is judged to be greater than 2. N -M, to determine whether the temperature collected by the sensor element is greater than the first preset temperature.

2. The infrared detector protection method according to claim 1, characterized in that: The reducing the temperature gain of the sensor element of the pixel includes: adjusting the input power of the sensor element of the pixel of the infrared detector to reduce the temperature gain of the sensor element of the pixel.

3. The infrared detector protection method according to claim 1, characterized in that: For any pixel of the infrared detector, the temperature collected by the sensor element of the pixel is divided into at least two temperature intervals, the at least two temperature intervals include a first temperature interval, the first temperature interval is less than or equal to the first preset temperature, and the temperature gain of the sensor element of the pixel corresponding to each of the temperature intervals is different; The method also includes: for any pixel of the infrared detector, determining the temperature interval to which the temperature collected by the sensor element of the pixel belongs, and controlling the temperature gain of the sensor element of the pixel to be consistent with the temperature gain corresponding to the temperature interval to which the temperature collected by the sensor element of the pixel belongs.

4. The infrared detector protection method according to claim 1, characterized in that: Also includes: For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to a second preset temperature, protective measures are performed on the infrared detector so that the temperature collected by the sensor element of each pixel of the infrared detector is less than the second preset temperature; wherein the second preset temperature is greater than the first preset temperature and less than or equal to the burning temperature of the sensor element of the infrared detector.

5. The infrared detector protection method according to claim 1, characterized in that: The protective measures for the infrared detector include: blocking light from entering the infrared detector or controlling the reduction of an aperture, wherein the aperture is used to control the amount of light energy incident on the infrared detector; Controls for stopping down the aperture include: Calculating the temperature attenuation coefficient of the highest temperature among the temperatures collected by the sensing elements of each pixel of the infrared detector relative to the second preset temperature; The aperture size is controlled so that the aperture size corresponds to the aperture value corresponding to the temperature attenuation coefficient.

6. The infrared detector protection method according to claim 1, characterized in that: Also includes: For any pixel of the infrared detector, if the temperature collected by the sensor element of the pixel is greater than or equal to a second preset temperature, the position of the high-temperature target in the image collected by the infrared detector is obtained; wherein the second preset temperature is greater than the first preset temperature and less than or equal to the burning temperature of the sensor element of the infrared detector; When the angle of the lens corresponding to the infrared detector changes, the angle change of the high-temperature target relative to the center of the image in the image collected by the infrared detector is obtained based on the relationship between the angle change of the object relative to the optical axis of the lens corresponding to the infrared detector and the angle change of the object image relative to the center of the image in the image collected by the infrared detector, as well as the angle change of the lens corresponding to the infrared detector, so as to judge whether the high-temperature target deviates from the field of view of the lens corresponding to the infrared detector.

7. The infrared detector protection method according to claim 6, characterized in that: If it is determined that the high-temperature target has deviated from the field of view of the lens corresponding to the infrared detector, the protection measures for the infrared detector are cancelled.

8. The infrared detector protection method according to claim 6, characterized in that: Also includes: If it is determined that the high temperature target will enter the field of view of the lens corresponding to the infrared detector again based on the angular change of the high temperature target relative to the center of the image collected by the infrared detector, a prompt is issued.

9. An infrared detector protection device, characterized in that: Used to execute the infrared detector protection method described in any one of claims 1-8.

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