Monitoring device and overexposure adjustment method

Abstract

The present invention relates to the field of intelligent monitoring technology, and in particular to a monitoring device and an overexposure adjustment method, wherein the monitoring device includes a camera module and a main control board, the camera module having a first light sensor; the camera module is arranged on the main control board; the main control board is provided with a plurality of infrared light-emitting modules and at least one second light sensor, the second light sensor being configured to detect the light intensity of reflected light and generate a corresponding electrical signal according to each light intensity, and the main control board adjusts the light intensity of the corresponding infrared light-emitting module according to each electrical signal, so that the light intensity value of the light received by the first light sensor in each direction converges to a preset dynamic range. The main purpose of the present invention is to provide a monitoring device that aims to solve the overexposure problem near the camera module while avoiding problems such as image blur and loss of details due to light intensity attenuation when the target is farther away.

Description

Technical Field

[0001] The present invention relates to the field of intelligent monitoring technology, and in particular to a monitoring device and an overexposure adjustment method. Background Art

[0002] Smart monitoring devices (such as smart doorbells, smart door locks, and smart cameras) are essential components of modern security systems. By integrating cameras, sensors, and communication modules, they enable real-time environmental monitoring, abnormal behavior alerts, and remote interaction. Their core value lies in leveraging artificial intelligence algorithms and IoT technology to transcend the passive response model of traditional security equipment, proactively sensing environmental changes and providing visual data support. For example, smart doorbells use facial recognition and motion detection to accurately distinguish between visitors and strangers. They also integrate cloud storage and mobile devices to provide users with round-the-clock front-door security, making them a key entry point into smart home scenarios.

[0003] Taking smart doorbells as an example, in actual deployment, their camera modules are often restricted by their physical installation locations (such as being close to walls or having obstructions), resulting in a decrease in the quality of infrared fill light imaging at night. Specifically, when an infrared LED light source shines on an adjacent wall, the infrared light reflected by the wall will form a local high-brightness area, causing the camera sensor to receive light intensity beyond the dynamic range, resulting in image overexposure. The existing technology usually adopts a solution of globally reducing the intensity of infrared light to suppress overexposure, but the applicant's research has found that this solution has significant drawbacks: although reducing the intensity of infrared light can alleviate the problem of overexposure in the near field, it will lead to insufficient fill light in the long-distance area, causing the camera to have problems such as blurred images and loss of details when shooting distant targets due to the attenuation of light intensity. Summary of the Invention

[0004] The main purpose of the present invention is to provide a monitoring device that aims to solve the overexposure problem of the camera module in the near distance while avoiding problems such as image blur and loss of details due to attenuation of light intensity when the target is far away.

[0005] To achieve the above objectives, the monitoring device proposed by the present invention includes:

[0006] a camera module having a first light sensor; and

[0007] A main control board, the camera module is arranged on the main control board; the main control board is provided with multiple infrared light-emitting modules and at least one second light sensor, the second light sensor is configured to detect the light intensity of the reflected light and generate a corresponding electrical signal according to each light intensity, and the main control board adjusts the light intensity of the corresponding infrared light-emitting module according to each electrical signal, so that the light intensity value of the light received by the first light sensor in each direction converges to a preset dynamic range.

[0008] In one embodiment of the present invention, the mounting surface of the main control board is set in a plane, the main control board has N infrared light-emitting modules and N second light sensors, the camera module is set near the end of the mounting surface of the main control board, the N infrared light-emitting modules are located on the mounting surface of the main control board along a first height, and the N second light sensors are located on the mounting surface of the main control board along a second height and below the infrared light-emitting module; the N infrared light-emitting modules and the N second light sensors are arranged at intervals along the first direction, and each infrared light-emitting module is arranged opposite to one second light sensor.

[0009] In one embodiment of the present invention, the main control board is provided with a first mounting surface, a second mounting surface and a third mounting surface, the second mounting surface is located between the first mounting surface and the third mounting surface, and the second mounting surface is set at an angle to the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module and a second light sensor, the camera module is arranged near the end of the main control board mounting surface, each infrared light-emitting module is located along the first height on the corresponding mounting surface of the main control board, and each second light sensor is located along the second height on the mounting surface of the main control board and below the infrared light-emitting module; each infrared light-emitting module and each second light sensor are arranged at intervals along the first direction, and each infrared light-emitting module is arranged opposite to one second light sensor.

[0010] In one embodiment of the present invention, the main control board is further provided with a ranging sensor, which is configured to detect the shortest distance between the monitoring device and the obstruction and generate a distance electrical signal; the main control board is further configured to calculate the initial driving current value corresponding to the infrared light-emitting module based on the distance electrical signal, and perform closed-loop correction on the initial driving current value based on the electrical signal generated by the second light sensor, so that the light intensity value received by the first light sensor converges to the preset dynamic range.

[0011] In one embodiment of the present invention, the optical axis of the distance measuring sensor is arranged parallel to the light emitting axis of the corresponding infrared light emitting module, and the field of view of the distance measuring sensor covers the illumination area of ​​the infrared light emitting module.

[0012] In one embodiment of the present invention, the second light sensor is a multispectral sensor, which has at least one visible light detection channel and one infrared detection channel. The visible light detection channel has a color temperature detection module, and the infrared detection channel is configured to detect the light intensity of the reflected light and generate a corresponding electrical signal according to the light intensity of each light; the main control board is further configured to adjust the luminous intensity of the corresponding infrared light-emitting module according to the color temperature signal of the visible light detection channel and the light intensity signal of the infrared detection channel.

[0013] In one embodiment of the present invention, both the visible light detection channel and the infrared detection channel are configured with narrow-band filters to separate reflection spectra of different wavelengths.

[0014] The present invention also provides an overexposure adjustment method, which comprises the following steps:

[0015] Inputting initial driving current to each infrared light emitting module;

[0016] acquiring a plurality of electrical signals generated by the reflected light intensity detected by the second light sensor under the initial driving current, and determining whether the plurality of electrical signals are within a preset current range;

[0017] When at least one of the electrical signals is not within the preset current range, the current is driven to adjust the current to each of the infrared light-emitting modules so that the light intensity value received by the first light sensor is within the preset dynamic range.

[0018] In one embodiment of the present invention, before inputting the initial driving current to each infrared light emitting module, the method further includes:

[0019] receiving a distance electrical signal from a distance measuring sensor, wherein the distance electrical signal is generated when the distance measuring sensor detects the shortest distance between the monitoring device and the obstruction;

[0020] generating an initial driving current according to the distance electrical signal;

[0021] The step of inputting an adjusted current to each of the infrared light-emitting modules when at least one of the electrical signals is not within a preset current range includes:

[0022] When at least one of the electrical signals is not within a preset current range, obtaining a deviation between the reflected light intensity of the second light sensor and a preset dynamic range, and generating a current adjustment amount according to the deviation;

[0023] An adjustment current is generated according to the initial driving current and the current adjustment amount, and the adjustment current is driven to each of the infrared light-emitting modules.

[0024] In one embodiment of the present invention, generating an adjustment current according to the initial driving current and the current adjustment amount and driving the adjustment current to each of the infrared light-emitting modules includes:

[0025] Acquire the ambient color temperature signal through the visible light detection channel of the multispectral sensor;

[0026] detecting the reflected infrared light intensity through the infrared detection channel of the multispectral sensor;

[0027] Calculating a color temperature compensation coefficient according to the ambient color temperature signal, and correcting the initial driving current based on the shortest distance and the color temperature compensation coefficient;

[0028] An adjustment current is generated based on the corrected initial driving current and the current adjustment amount, and the adjustment current is driven to each of the infrared light-emitting modules.

[0029] In the technical solution of the present invention, the second light sensor directly detects the reflected light intensity of each LED array, accurately locates the overexposed area (such as wall reflection), and avoids the delay problem of traditional solutions that rely on camera imaging feedback; the first light sensor calibrates the target light intensity range based on the overall luminous flux of the imaging surface to ensure the final imaging quality, and achieves a dynamic balance of "near-field light reduction and far-field fill light" by adjusting the driving current of each LED in real time; through multiple independently light-controlled infrared LED arrays, the fill light intensity can be adjusted separately for different distance / direction areas (such as near-field walls and far-field targets), rather than globally uniformly reducing the light. When the near-field reflected light is detected to be too strong, only the power of the LED in the corresponding direction is reduced, while the far-field direction still maintains high light intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0031] Figure 1 A schematic structural diagram of an embodiment of a monitoring device provided by the present invention;

[0032] Figure 2 To correspond Figure 1 Schematic diagram of light rays of the structure shown;

[0033] Figure 3 A schematic structural diagram of another embodiment of the monitoring device provided by the present invention;

[0034] Figure 4 To correspond Figure 3 Schematic diagram of light rays of the structure shown;

[0035] Figure 5 This is a flow chart of a first embodiment of the overexposure adjustment method provided by the present invention;

[0036] Figure 6 This is a flow chart of a second embodiment of the overexposure adjustment method provided by the present invention;

[0037] Figure 7This is a flow chart of a third embodiment of the overexposure adjustment method provided by the present invention;

[0038] Figure 8 This is a flow chart of a fourth embodiment of the overexposure adjustment method provided by the present invention.

[0039] Description of Figure Numbers:

[0040] 10. Camera module; 20. Main control board; 21. Infrared light emitting module; 22. Second light sensor.

[0041] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] In existing technologies, intelligent monitoring devices often suffer from uneven fill lighting due to limited installation locations. When infrared light strikes adjacent walls, the reflected light creates localized highlights, causing overexposure. Traditional solutions mitigate this by reducing light intensity globally, but this results in insufficient fill lighting at long distances, blurring the image of the target object. For example, a smart doorbell mounted on a wall has infrared light that covers both the near-end wall and the far-end pedestrian walkway. A single intensity adjustment cannot meet the fill lighting requirements of different areas.

[0046] To address the above issues, the inventors discovered that reflected light intensities vary significantly across different regions. Relying solely on a single light intensity adjustment method would not be able to effectively balance the fill light needs of each region. By analyzing the light reflection paths, they discovered that the reflection areas corresponding to each light-emitting unit have independent light intensity characteristics. Based on this, they proposed the idea of ​​independently controlling each light-emitting unit. By setting up multiple light detection units to collect the reflected light signals from the corresponding areas, they achieved regional light intensity adjustment.

[0047] Therefore, the present application proposes a monitoring device comprising a camera module 10 and a main control board 20. The camera module 10 is provided with a first light sensor; the main control board 20 is provided with multiple infrared light modules 21 and at least one second light sensor 22. The second light sensor 22 detects the intensity of the reflected light and generates an electrical signal. The main control board 20 adjusts the intensity of the corresponding infrared light module 21 based on the electrical signal to ensure that the light intensity received by the first light sensor is within a preset dynamic range.

[0048] Among them, the first light sensor refers to a photosensitive element arranged inside the camera module 10, which can be specifically implemented by a photosensitive unit of a CMOS or CCD image sensor, and is used to monitor the actual light intensity entering the camera module 10 in real time; the second light sensor 22 refers to a photosensitive device independent of the camera module 10, which can be specifically implemented by a photodiode array, each photodiode corresponds to an irradiation area of ​​an infrared light-emitting module 21, and is used to detect the intensity of the reflected light in the area. The infrared light-emitting module 21 refers to a light-emitting unit with an independent driving circuit, which can be specifically formed by arranging multiple groups of infrared LED lamp beads, and the driving current of each group of lamp beads can be adjusted separately. The dynamic range refers to the light intensity range in which the photosensitive element of the camera module 10 can clearly image, avoiding overexposure (too high light intensity) or underexposure (too low light intensity), which can be specifically determined by the exposure parameter threshold preset by the image processing chip.

[0049] Specifically, when the infrared light emitted by the infrared light-emitting module 21 irradiates the monitoring area, the light intensity reflected by objects at different distances is different. The second light sensor 22 array respectively detects the reflected light intensity of the corresponding area of ​​each infrared light-emitting module 21, and generates an electrical signal corresponding to the light intensity of each area. In this process, the main control board 20 first inputs an initial driving current to each infrared light-emitting module 21 in a time-sharing manner. The light intensity generated by each infrared light-emitting module 21 under the same initial driving current is roughly consistent, and the light intensity detected by the second light sensor 22 will also be consistent. When there is an obstruction such as a wall on one side of a certain infrared light-emitting module 21 of the monitoring device, due to the reflection of the wall, the light intensity detected by the photosensitive element of the second light sensor 22 when detecting the infrared light-emitting module 21 will be greater than the light intensity obtained by detecting other infrared light-emitting modules 21 due to the reflected light intensity. The photosensitive element will generate a corresponding electrical signal change according to the received light intensity, and the generated electrical signal will be transmitted from the second light sensor 22 through the corresponding wiring on the wire or printed circuit board (PCB). The electrical signal is input to a specific signal receiving port or pin on the main control board 20. The signal receiving circuit on the main control board 20 (including signal conditioning circuits such as amplifiers and filters) first performs preliminary processing on the received electrical signal to remove noise and amplify the signal amplitude. Then, the microcontroller or processor in the main control board 20 reads the processed electrical signal and performs analog-to-digital conversion (ADC) to convert the analog electrical signal into a digital signal. Upon determining that there is an obstruction on one side of a certain infrared light-emitting module 21 of the monitoring device, the main control board 20 reduces the current of the infrared light-emitting module 21 on the side closer to the obstruction. At the same time, to ensure that the overall light intensity remains unchanged and avoid blurred images at a distance, the current of the infrared light-emitting module 21 on the side farther from the obstruction is increased. This ensures that the intensity of each light detected by the second light sensor 22 is consistent, and thus the intensity of light incident on the first sensor in all directions is basically consistent, thereby eliminating the problem of infrared overexposure while avoiding blurred images at a distance. Here, "roughly consistent" is because the light output intensity of each lamp bead under the same initial driving current cannot be completely consistent due to slight differences in material uniformity, chip size, packaging process, etc. between the lamp beads of each infrared light-emitting module 21. Therefore, it is only necessary to ensure that the light output intensity of each infrared light-emitting module 21 is in the light intensity area with the benchmark value as the midpoint.

[0050] Through the above technical solution, the present application solves the contradiction between near-end overexposure and far-end underexposure caused by single light intensity adjustment in the prior art, enabling the monitoring device to automatically balance the fill light intensity of each area in a complex lighting environment, thereby improving the imaging clarity of objects at different distances and avoiding the loss of image details due to local overbrightness or darkness.

[0051] In some embodiments, the mounting surface of the main control board 20 is set in a plane, the main control board 20 has N infrared light-emitting modules 21 and N second light sensors 22, the camera module 10 is set near the end of the mounting surface of the main control board 20, the N infrared light-emitting modules 21 are located on the mounting surface of the main control board 20 along the first height, and the N second light sensors 22 are located on the mounting surface of the main control board 20 along the second height and below the infrared light-emitting module 21; the N infrared light-emitting modules 21 and the N second light sensors 22 are arranged at intervals along the first direction, and each infrared light-emitting module 21 is arranged opposite to a second light sensor 22.

[0052] The installation surface of the main control board 20 is in a flat configuration, which means that the surface of the main control board 20 used to carry the infrared light-emitting module 21 and the second light sensor 22 is a flat structure, which can be implemented by a rectangular or circular plate. This flat structure facilitates the installation of the infrared light-emitting module 21 and the second light sensor 22 according to a preset layout. The first height and the second height refer to the different positioning positions of the infrared light-emitting module 21 and the second light sensor 22 in the vertical direction of the installation surface, which can be implemented by a layered arrangement or a stepped layout. This height difference can avoid light interference caused by direct illumination of the infrared light-emitting module 21. The alignment setting means that there is a spatial correlation between the horizontal projection position of a single infrared light-emitting module 21 and its corresponding second light sensor 22 on the installation surface, which can be implemented by a symmetrical arrangement or a staggered arrangement. This structure can ensure that the reflected light detection area and the fill light area form a corresponding relationship.

[0053] Specifically, the planar mounting surface of the main control board 20 can realize the regular arrangement of multiple infrared light emitting modules 21 and second light sensors 22. In one embodiment, please refer to Figure 1 and Figure 2When the camera module 10 is close to the end of the mounting surface, the three infrared light-emitting modules 21 form a horizontal array along the first height, and the emitted light covers monitoring areas of different distances; the three infrared light-emitting modules 21 form a horizontal array along the first direction at the second height, so that each infrared light-emitting module 21 is set to a second light sensor 22. The second light sensor 22 is located below the infrared light-emitting module 21 and can receive the reflected light after the corresponding infrared light-emitting module 21 irradiates the wall or object. Each second light sensor 22 independently detects the reflected light intensity of the area illuminated by its corresponding infrared light-emitting module 21 and generates an independent electrical signal. The main control board 20 adjusts the current value of the corresponding infrared light-emitting module 21 according to each electrical signal. For example, when the reflected light intensity in a certain area is too high, the output power of the infrared light-emitting module 21 at that position is reduced, while the fill light intensity is increased in areas with insufficient reflected light intensity, thereby realizing independent dimming control of different monitoring areas. By arranging multiple independently controlled infrared light-emitting modules 21 and corresponding second light sensors 22 in layers according to height on a flat mounting surface, regional light intensity detection and adjustment is achieved. When the second light sensor 22 corresponding to a certain infrared light-emitting module 21 detects local overexposure, it is only necessary to adjust the output of the infrared light-emitting module 21 without reducing the overall fill light intensity, thereby maintaining the fill light effect in the far-field area while suppressing near-field overexposure. In addition, multiple infrared light-emitting modules 21 are arranged at intervals along the first direction on a mounting surface so that the monitoring device can obtain a larger light-emitting area, so that the camera module 10 can obtain more monitoring information.

[0054] In some other embodiments, the main control board 20 is provided with a first mounting surface, a second mounting surface, and a third mounting surface, the second mounting surface being located between the first mounting surface and the third mounting surface, and the second mounting surface being arranged at an angle to both the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module 21 and a second light sensor 22, the camera module 10 is arranged near the end of the mounting surface of the main control board 20, each infrared light-emitting module 21 is located along a first height on the corresponding mounting surface of the main control board 20, and each second light sensor 22 is located along a second height on the mounting surface of the main control board 20 and below the infrared light-emitting module 21; each infrared light-emitting module 21 and each second light sensor 22 are spaced apart along a first direction, and each infrared light-emitting module 21 is arranged in alignment with a second light sensor 22. The mounting surface of the main control board 20 refers to a structural substrate that supports electronic devices, and can be implemented as a rigid circuit board or a flexible substrate, and is used to fix the spatial positions of the infrared light-emitting module 21 and the second light sensor 22.

[0055] Among them, the installation surface is set at an angle, which means that a non-parallel spatial relationship is formed between adjacent surfaces. It can be achieved through a bending process or split assembly to adjust the light coverage angle to avoid interference from single plane reflection.

[0056] In one embodiment, see Figure 3 and Figure 4 The three mounting surfaces of the main control board 20 form a stepped layout, wherein the second mounting surface serves as an intermediate transition portion, forming a non-coplanar structure with the first mounting surface and the third mounting surface on both sides, wherein the angles formed by the second mounting surface and the first mounting surface and the third mounting surface on both sides are consistent, and each mounting surface is independently arranged with an infrared light-emitting module 21 and a second light sensor 22, the infrared light-emitting module 21 is located at the upper part of the mounting surface, and the second light sensor 22 is located at the lower part and is arranged at intervals with the corresponding infrared light-emitting module 21 in the horizontal direction. When the device is working, each infrared light-emitting module 21 projects light at different angles, and the second light sensor 22 detects the intensity of the reflected light in real time and feeds it back to the main control board 20. The main control board 20 independently adjusts the driving current of the corresponding infrared light-emitting module 21 based on the electrical signals of each sensor, so that the intensity of the reflected light received by the camera module 10 is always maintained within the dynamic range. The non-coplanar mounting surface enables the infrared light-emitting module 21 to emit light outward from different angles, and the second light sensor 22 can also receive reflected light from different angles. The non-coplanar mounting surface can cover a wider three-dimensional space, reduce lighting blind spots, improve the details and quality of the monitoring image, and is suitable for complex environments; at the same time, the non-coplanar mounting surface enables each infrared light-emitting module 21 and the second light sensor 22 to correspond to a specific area and angle, and the main control board 20 can accurately adjust the light intensity of the specific area according to its electrical signal, realizing precise and independent dimming of each area, and better meeting the fill light needs of different areas; at the same time, the non-coplanar setting is more advantageous in a small or irregular space, which facilitates the miniaturization design of the product.

[0057] Furthermore, the main control board 20 is also provided with a ranging sensor, which is configured to detect the shortest distance between the monitoring device and the obstruction and generate a distance electrical signal; the main control board 20 is also configured to calculate the initial driving current value of the corresponding infrared light-emitting module 21 based on the distance electrical signal, and adjust the initial driving current value according to the electrical signal generated by the second light sensor 22, so that the light intensity value received by the first light sensor is within a preset dynamic range.

[0058] First of all, it needs to be explained that a ranging sensor refers to a hardware module that can detect the distance between an object and a monitoring device. Common types include time-of-flight (ToF) sensors, ultrasonic sensors, or structured light sensors. Its core function is to transmit signals (such as infrared light, ultrasonic waves) and receive reflected signals, calculate the round-trip time or phase difference of the signals, and thus obtain the distance value; the shortest distance refers to the minimum straight-line distance between the monitoring device and the obstruction. For example, when a wall partially blocks the camera, the ranging sensor will prioritize detecting the distance to the nearest point; the distance electrical signal is a quantized signal output by the ranging sensor, usually a digital value (such as centimeter-level distance data output by the I²C / SPI interface) or an analog voltage signal (which needs to be converted into a digital value by an ADC); the initial driving current value is the preliminary driving current of the infrared light-emitting module 21 (IRLED) obtained based on the distance electrical signal through a pre-stored algorithm (such as a lookup table method, formula calculation), which is used to quickly respond to changes in the distance to the obstruction.

[0059] Specifically, a distance sensor detects the shortest distance between the obstruction and the monitoring device in real time and generates a distance electrical signal. The main control board 20 first calculates the initial drive current for the infrared light-emitting module 21 based on the distance electrical signal (for example, the closer the distance, the lower the drive current to compensate for excessive reflected light). The main control board 20 then modifies the initial drive current (e.g., PID adjustment) based on the actual reflected light intensity detected by the second light sensor 22 (ALS), ultimately ensuring that the light intensity received by the camera's first light sensor converges within a preset dynamic range. This solution, through a composite mode of feedforward control (distance prediction) combined with feedback control (light intensity correction), rapidly responds to changes in the distance of the obstruction while ensuring compensation accuracy. This addresses the issues of high latency in single feedback control or susceptibility to environmental interference in single feedforward control. In one embodiment, a wall obstruction exists on the left side of the monitoring device. The distance sensor detects the shortest distance D to the wall as d and generates a corresponding distance electrical signal, which is transmitted to the main control board 20. The main control board 20 then calls a pre-stored calibration formula I itial =K / D 2 (Unit: mA, D is meter, K is the comprehensive calibration coefficient). First, according to the inverse square law of light, "the intensity of the action of an object or particle decreases linearly with the square of the distance, that is, the force is inversely proportional to the square of the distance", we can know that: L∝1 / D 2 , further, assuming that the required driving current is I0 at a reference shortest distance D0, and the light intensity generated by an infrared light emitting module 21 is L0, in actual application, when the distance becomes D, in order to maintain the same light intensity L0, the driving current needs to be adjusted to I, so that ,Will Defined as the comprehensive calibration coefficient K, so that the light intensity-current-distance relationship of the actual system is obtained by experimental calibration , considering the reflectivity of the white wall is , thus obtaining Based on the obtained calibration formula, the target light intensity L is determined under the setting of the reflectivity of the obstruction ρ0 and the distance d in an experimental test environment. target When L1 is used, the target current value of the input infrared module is I target , thus the comprehensive calibration coefficient can be obtained When the monitoring device is used in an actual scene, the reflectivity of the obstruction is ρ1 and the distance is d1, it can be obtained , based on the actual distance d1 between the monitoring device and the obstruction, the actual current can be obtained When the reflected light intensity detected by the left second light sensor 22 is greater than the reflected light intensity detected by the other second light sensors 22, the main control board 20 determines that there is overexposure on this side and defines the deviation intensity as , the PID parameters are adjusted by trial and error. Specifically, , where K p is the proportional coefficient, K i is the integral coefficient, K d is the differential coefficient, which reduces the initial drive current to , and the reflected light intensity is detected again as L2, and the error is reduced to , after multiple iterations of adjustments , thereby determining the reflectivity of the occluder based on , the distance is When the final current passing through the infrared light emitting module 21 is At this time, the detection value of the second light sensor 22 on the left side is , can fall into the preset dynamic range and lock Operation; A procedural explanation of the above scheme is given. Before the monitoring device leaves the factory, parameter debugging is performed to determine the calibration coefficient K and the initial driving current. That is, under laboratory conditions, an obstruction of a known distance D is set, and a material with a standard reflectivity (such as a white wall) is selected as the obstruction. The driving current of the infrared light-emitting module 21 is adjusted until the light intensity received by the first light sensor of the camera module 10 reaches the optimal value within the preset dynamic range. The driving current recorded at this time is the initial driving current. Using the calibration formula, combined with the experimental distance D and the initial drive current, a comprehensive calibration coefficient K is calculated. This K value serves as the basis for calculating the initial drive current in subsequent real-world scenarios. When the monitoring device is installed in a real-world scenario, the ranging sensor begins operating, measuring the actual shortest distance between the monitoring device and the obstruction. Simultaneously, the system needs to determine the obstruction's reflectivity, which can be estimated using a preset default reflectivity (if the obstruction type is known) or by measuring the reflected light intensity in real time. Based on the actual shortest distance measured by the ranging sensor, the calibration coefficient K, obtained during the calibration process, is used to calculate a new initial drive current. This initial drive current accounts for distance variations in actual application scenarios. Because the reflectivity of obstructions in real-world scenarios differs from that in experimental environments, the calibration coefficient K needs to be corrected. This correction process is based on the difference between the actual reflectivity and the experimental reflectivity. The corrected K value more accurately reflects the light intensity-current-distance relationship in real-world scenarios, thereby improving control accuracy. The main control board 20 sets the drive current for the infrared light-emitting module 21 based on the corrected K value and the initial drive current calculated based on the actual shortest distance. The second light sensor 22 detects the reflected light intensity at this time and generates an electrical signal that is fed back to the main control board 20. Based on the feedback from the second light sensor 22, the main control board 20 determines whether the current light intensity is within the preset dynamic range. If the light intensity exceeds the range (too strong or too weak), the main control board 20 will adjust the drive current. After each adjustment, the new light intensity is detected by the second light sensor 22 until the light intensity stabilizes within the preset dynamic range. Once the reflected light intensity stabilizes within the preset dynamic range, the main control board 20 locks the current drive current value, and the monitoring device operates stably under this parameter. At the same time, the main control board 20 continues to monitor changes in light intensity, preparing to make new adjustments when environmental conditions change. Through the above process, the monitoring device can automatically adjust the drive current of the infrared light-emitting module 21 under different environmental conditions, ensuring that the light intensity received by the camera module 10 is always within the optimal range, thereby improving image quality and avoiding the loss of image details due to local overbrightness or darkness.

[0060] Furthermore, the optical axis of the ranging sensor is arranged parallel to the light-emitting axis of the corresponding infrared light-emitting module 21, and the field of view angle of the ranging sensor covers the illumination area of ​​the infrared light-emitting module 21. It should be explained that the optical axis refers to the central axis direction of the ranging sensor transmitting / receiving signals, which determines the spatial orientation of its detection area; the light-emitting axis refers to the central axis direction of the infrared light-emitting module 21 (IRLED) emitting infrared light; the field of view angle refers to the angular range in which the ranging sensor can effectively detect objects. For example, a horizontal field of view angle of 60° indicates that objects within this angle can be detected; the illumination area refers to the spatial range covered by the infrared light emitted by the infrared light-emitting module 21, which is determined by the emitting angle and installation position of the infrared light-emitting module 21.

[0061] Specifically, if an infrared light-emitting module 21 is responsible for illuminating the left side, the corresponding ranging sensor's field of view must completely cover that left side. This design ensures that the distance detected by the ranging sensor strictly corresponds to the actual infrared light illumination area, avoiding distance detection errors caused by optical path deviations (such as the ranging sensor detecting the distance to the right side but using it to adjust the left IRLED). Furthermore, the field of view coverage requirement ensures that all potential obstructions within the infrared light illumination range are captured by the ranging sensor, thereby improving the comprehensiveness of distance detection and the accuracy of the compensation strategy.

[0062] In one embodiment, the second light sensor 22 is a multispectral sensor having at least one visible light detection channel and one infrared detection channel. The visible light detection channel includes a color temperature detection module, and the infrared detection channel is configured to detect the intensity of reflected light and generate corresponding electrical signals based on the intensity of each light. The main control board 20 is further configured to adjust the luminous intensity of the corresponding infrared light-emitting module 21 based on the color temperature signal from the visible light detection channel and the light intensity signal from the infrared detection channel. A multispectral sensor is a composite sensor that integrates visible and infrared light detection capabilities, including independent visible light and infrared channels. It can simultaneously acquire ambient color temperature and infrared reflected light intensity data, such as an RGB-IR sensor (such as the Vishay VEML6040) or a spectroscopic multi-channel sensor (such as the ams AS7265x). The visible light detection channel of a multispectral sensor is the module in the sensor used to detect the visible light band (380-780nm), typically including three sub-channels: red (R), green (G), and blue (B). The color temperature detection module calculates the color temperature of the ambient light source (unit: K) from the RGB response value, for example based on the McCamy formula or the blackbody radiation curve interpolation algorithm. The color temperature signal refers to the quantified color temperature value of the ambient light source output by the visible light detection channel, which is used to characterize the "cold" and "warm" characteristics of the light source (such as 2700K for warm light and 6500K for cold light). The infrared detection channel is the module in the sensor used to detect infrared bands (such as 850±10nm). It is equipped with a narrowband filter to isolate ambient light outside the fill light band. It detects the intensity of the light reflected from the infrared light-emitting module and generates an electrical signal proportional to the light intensity. The light intensity signal is the quantified value of the reflected light intensity output by the infrared detection channel, which is used to feedback the actual fill light effect of the IR LED. Specifically, the visible light detection channel measures the ambient color temperature in real time, and the infrared detection channel measures the intensity of IRLED reflected light in all directions. The reference current of the IRLED is dynamically adjusted according to the ambient color temperature. For example, in a low color temperature environment (such as 2700K warm light), IR compensation is enhanced to offset red light interference. First, the color temperature compensation coefficient is obtained:

[0063] ,

[0064] Among them, CCT is the color temperature of the current ambient light source; CCT ref is the reference color temperature value; K p is the proportional coefficient, which controls the adjustment intensity of the compensation coefficient by the color temperature deviation. Then, based on the feedback signal of the infrared detection channel, the current is adjusted through the PID algorithm to eliminate the light intensity deviation. The formula is as follows:

[0065] ,

[0066] in, is the current adjustment amount, which is a correction value dynamically calculated according to the light intensity deviation; is the target light intensity (L 预设 ) and the actual detection light intensity (L IR ) of the light intensity deviation; Based on the above, , output final current Drive the infrared light emitting module 21; in one scenario, the monitoring device is installed in a warm light porch (color temperature 2700K), with a white wall (reflectivity 0.8) on the left and no obstruction on the right. The visible light channel of the multispectral sensor is based on a CCT of 2700K. =1.2, the light intensity detected by the multispectral sensor close to the white wall obstruction is greater than the light intensity detected by the multispectral sensor far away from the white wall obstruction. Through the above technical solution, the driving current of the infrared light emitting module 21 close to the white wall obstruction is reduced from the initial driving current Adjust to , the infrared light emitting module 21 away from the white wall obstruction is 0, so the driving current is the initial driving current This technical solution fuses color temperature and infrared light intensity data through a multispectral sensor, combined with a dynamic compensation algorithm. While addressing overexposure and ensuring sufficient far-field fill light, it can also identify different ambient light color temperatures to achieve environmentally adaptive infrared fill light control.

[0067] In one embodiment, the monitoring device is parameterized before leaving the factory, and a known distance D is set. ref The shielding material with standard reflectivity is selected as the shielding material, and the driving current of the infrared light emitting module 21 is adjusted until the light intensity received by the first light sensor of the camera module 10 is within the optimal value within the preset dynamic range, and the driving current at this time is recorded as the basic driving current I basis , and record the color temperature CCT at this time ref When the monitoring device is installed in the actual scene, the distance sensor starts working to measure the actual distance D between the monitoring device and the obstruction. The multispectral sensor measures the color temperature CCT and reflected light intensity of the ambient light in real time. The infrared detection channel generates an electrical signal proportional to the reflected light intensity. The main control board 20 generates an electrical signal proportional to the current ambient color temperature CCT and the reference color temperature CCT. ref , using the formula , calculate the color temperature compensation coefficient α cct At the same time, the main control board 20 calculates the actual distance D and the reference distance D ref , using the formula α distance =(D ref / D)²Calculate the distance adjustment coefficient α distance , then according to the basic driving current I basis , color temperature compensation coefficient α cct and distance adjustment coefficient α distance , calculate the preliminary driving current: I initial =Ibasis ×α cct ×α distance The main control board 20 is based on the deviation of the actual reflected light intensity and the target light intensity fed back by the infrared detection channel of the multi-spectral sensor. , , calculate the feedback adjustment current , the main control board 20 is based on the initial driving current I initial and feedback to adjust the current , calculate the final drive current , and drives the infrared light-emitting module 21; specifically, in one embodiment, the monitoring device is installed in an environment with warm light illumination, with the left side close to a white wall (reflectivity 0.8), the right side is a channel area, and there is no obstruction. The camera module 10 is set close to the end of the mounting surface of the main control board 20. The main control board 20 is provided with three infrared light-emitting modules 21 and three multispectral sensors. Each infrared light-emitting module 21 is set to a multispectral sensor. Before this, parameter calibration is performed and the obstruction distance is set to D ref =1m, ambient color temperature is CCT ref =6500K, adjust the driving current of the infrared light emitting module 21 so that the light intensity received by the first light sensor of the camera module 10 is in the optimal state, and record the basic driving current I basis =200mA; In the warm light lighting installation scenario, the distance between the left infrared light emitting module 21 and the white wall measured by the distance sensor is D left =0.5m, the distance between the right infrared light emitting module 21 and the channel area is D right =3m, the multispectral sensor detects the current ambient color temperature CCT = 2700K, set =0.01, the main control board 20 calculates the color temperature compensation coefficient of the left infrared light emitting module 21 according to the formula =1+0.01×(6500-2700)=1.38, color temperature compensation coefficient of the right infrared light emitting module 21 =1+0.01×(6500-2700)=1.38, the main control board 20 calculates the distance adjustment coefficient α of the left infrared light emitting module 21 according to the formula distanceleft =(1 / 0.5)²=4, the distance adjustment coefficient α of the right infrared light emitting module 21 distanceright =(1 / 3)²=0.111, the main control board 20 calculates the initial driving current I of the left infrared light emitting module 21 initialleft =200mA×1.38×4=1099.2mA, the initial driving current of the right infrared light-emitting module 21 I initialright =200mA×1.38×0.111=30.108mA. Assuming that the multispectral sensor detects that the actual reflected light intensity on the left is higher than the target light intensity, the deviation is =50Lux, the actual reflected light intensity on the right is lower than the target light intensity, the deviation is =-30Lux. Set K p =0.5, K i =0.1, K d =0.05, the left feedback adjustment current is calculated by PID algorithm (Assuming ∑50 is the sum of the cumulative errors of the previous times, and d50 / dt is the error change rate), the feedback on the right side adjusts the current , the final driving current of the left infrared light emitting module 21 , the final driving current of the infrared light emitting module 21 on the right side The main control board 20 drives the infrared light emitting module 21 according to the calculation results, and the main control board 20 continuously adjusts the reflected light intensity data continuously fed back by the multi-spectral sensor. , until the reflected light intensity is stable within the preset dynamic range. Finally, the driving current of the left infrared light emitting module 21 is stabilized at I finalleft =1050mA, the driving current of the right infrared light emitting module 21 is stable at I finalright =40mA, the monitoring device operates stably under this parameter. In the image captured by the camera module 10, the left area is not overexposed and the right area has sufficient fill light. In this way, objects at different distances are clearly imaged, so that the image is rich in details.

[0068] In some embodiments, both the visible light detection channel and the infrared detection channel are configured with narrowband filters to separate reflection spectra of different wavelengths. Specifically, the visible light and infrared detection channels of the multispectral sensor are both configured with narrowband filters. By accurately separating the reflection spectra of different wavelengths, signal purity and anti-interference capabilities are improved. In one embodiment, the visible light channel of the multispectral sensor is configured with three sets of narrowband filters (red light 650nm±10nm, green light 550nm±10nm, blue light 450nm±10nm) for separating the RGB spectrum and calculating the ambient color temperature; the infrared channel is configured with an 850nm±10nm narrowband filter, which only transmits the reflected light in the IRLED fill light band and filters out near-infrared stray light in sunlight (such as 800-900nm). Under this design, the visible light channel optimizes the infrared compensation strategy through precise color temperature detection (such as distinguishing 2700K warm light from 6500K cold light), while the infrared channel suppresses ambient light interference during the day to ensure consistency in reflected light intensity detection at night and during the day. For example, when a smart doorbell is installed in direct sunlight, an 850nm filter blocks 840-860nm stray light in sunlight, preventing the ALS from misinterpreting it as a high-reflection signal and preventing far-field underexposure caused by abnormal IR LED current drop. In another embodiment, the multispectral sensor's visible light channel incorporates cool white (480nm±5nm) and amber (600nm±10nm) narrowband filters to enhance its ability to resolve mixed light sources (such as natural light, incandescent lamps, and LEDs). The infrared channel incorporates 940nm±20nm wide- and narrowband filters to match invisible infrared fill light LEDs and accommodate wavelength temperature drift (±15nm). In this solution, the cool white light channel identifies high-color-temperature ambient light (such as neon signs in shopping malls) and triggers dynamic adjustment of the IR compensation intensity. The 940nm wide- and narrowband filters prevent fill light exposure in covert surveillance scenarios (such as bank vaults) while allowing for slight LED wavelength shifts (such as temperature-induced drift from 935-945nm) to effectively transmit the signal. For example, when security cameras are deployed in commercial areas with severe light pollution, a 480nm filter precisely isolates interference from cool white light, combined with a 940nm covert fill light to ensure clear nighttime imaging without exposing the device's location. In this way, narrowband filters are configured for both the visible light and infrared channels to isolate interference from non-target bands and enhance signal purity. Visible light detects color temperature, while infrared detects light intensity. Data fusion drives dynamic compensation, improving anti-interference capabilities and effectively suppressing contamination of detection signals by ambient stray light (such as sunlight and artificial light sources).

[0069] This application also proposes an overexposure adjustment method for a monitoring device. Figure 5 , overexposure adjustment methods include:

[0070] Step S20: inputting an initial driving current to each infrared light emitting module 21;

[0071] Step S30: acquiring a plurality of electrical signals generated by the reflected light intensity detected by the second light sensor 22 under the initial driving current, and determining whether the plurality of electrical signals are within a preset current range;

[0072] Step S40 : When at least one electrical signal is not within the preset current range, inputting an adjustment current to each infrared light-emitting module 21 so that the light intensity value received by the first light sensor is within the preset dynamic range.

[0073] It can be understood that the overexposure adjustment method proposed in this application is applied to the monitoring device proposed above, and the monitoring device can be used in multiple scenarios, such as being installed at home entrances, factories, municipal parks, parking lots, etc., which are not limited here.

[0074] In step S20, the initial drive current provides the starting operating current for the infrared light-emitting module 21, causing it to begin emitting infrared light. The main control board 20 outputs a predetermined initial drive current to each infrared light-emitting module 21. This current value is typically determined based on previous experience or experimental calibration, and is intended to ensure that the infrared light-emitting module 21 outputs appropriate light intensity under ideal conditions such as clear visibility. For example, in a smart doorbell scenario, all infrared emission modules are started with the same current (e.g., 200mA) to avoid instantaneous overexposure due to a sudden increase in one side.

[0075] In step S30, the second light sensor 22 (e.g., a photodiode array) detects the reflected light intensity of the corresponding area of ​​each infrared light-emitting module 21 in real time and converts it into an electrical signal (e.g., a voltage value). The main control board 20 compares the electrical signal with a preset current range (e.g., 0.5 to 2.0V corresponding to 50 to 200 Lux) to identify abnormal areas. For example, if the left sensor detects 2.5V (corresponding to 250 Lux), the area is determined to be overexposed.

[0076] In step S40, based on the feedback from the second sensor, the main control board 20 dynamically adjusts the current of the infrared light-emitting module 21 corresponding to the abnormal area using a PID algorithm. For example, the current of the left infrared light-emitting module 21 is reduced from 200mA to 150mA, while the current of the right infrared light-emitting module 21 is increased from 200mA to 250mA. This stabilizes the overall light intensity received by the first light sensor (CMOS photosensitive unit) of the camera module 10 within a preset dynamic range (e.g., 100±20lux).

[0077] In this way, by providing multiple independently driven infrared adjustment modules, the conflict between near-end overexposure and far-end underexposure caused by single-source light intensity adjustment in traditional monitoring devices is effectively resolved. Specifically, the second light sensor 22 array independently detects the reflected light intensity of the corresponding area of ​​each infrared light-emitting module 21. Combined with the global light intensity verification of the first light sensor, this achieves precise current reduction in locally overexposed areas and targeted fill light in underexposed areas. For example, in a smart doorbell scenario, the current of the infrared light-emitting module 21 near the wall is reduced to suppress reflected overexposure, while the current of the module in the far pedestrian passage is simultaneously increased to ensure clear imaging of distant targets. This method not only avoids the image quality degradation caused by traditional global dimming, but also significantly improves overall imaging uniformity in complex spaces through a two-stage feedback mechanism (local detection + global balancing). It is particularly suitable for installation environments with significant reflection differences (such as corridors and corners).

[0078] See also Figure 6 , before step S20, further comprising:

[0079] Step S10: receiving a distance electrical signal from a distance measuring sensor, where the distance electrical signal is generated when the distance measuring sensor detects the shortest distance between the monitoring device and the obstruction;

[0080] Step S11: generating an initial driving current according to the distance electrical signal;

[0081] In step S10, the ranging sensor is electrically connected to the power module and main control board 20 of the main control device. The ranging sensor (such as a ToF module) detects the shortest distance between the monitoring device and the obstruction (such as 0.5m from the wall) and generates a digital signal (such as an I²C interface output distance value). This step mainly provides key input for feedforward control. For example, in a corridor monitoring scenario, the distance to the nearest obstacle (such as a pillar) is prioritized rather than the distance to the far ground (3m).

[0082] In step S11, the main control board 20 calls the pre-stored calibration formula I initial =K / D² (K is the calibration factor, D is the distance value) to calculate the initial drive current. For example, when K = 200mA·m² and D = 0.5m, I_initial = 200 / (0.5²) = 800mA. This step uses the inverse square law to pre-compensate, shortening the adjustment time and avoiding the overexposure delay caused by sudden distance changes in traditional solutions.

[0083] See also Figure 7 , step S40, further comprising:

[0084] Step S41: when at least one electrical signal is not within a preset current range, obtaining a deviation between the reflected light intensity of the second light sensor 22 and a preset dynamic range, and generating a current adjustment value according to the deviation;

[0085] Step S42 : generating an adjustment current according to the initial driving current and the current adjustment amount, and driving the adjustment current to each infrared light-emitting module 21 .

[0086] In step S41, the main control board 20 calculates the deviation between the detection value of the second light sensor 22 and the target value. , through the PID formula , , dynamically generate the adjustment amount, for example, if the reflected light intensity on the left exceeds the target value, the PID calculation This step combines feedforward and feedback control to eliminate the impact of differences in ambient reflectivity (such as white walls and dark walls) on dimming.

[0087] In step S42, the initial driving current is superimposed on the adjustment amount, I final =I initial + , driving the corresponding infrared light-emitting module 21 in different regions. In this step, dynamic balance is achieved to achieve near-end downflow to suppress overexposure and far-end upflow to maintain fill light, ensuring clear global imaging of the camera module 10.

[0088] In this way, the distance to the obstruction is acquired in real time by the ranging sensor and the initial drive current is generated (based on inverse square law pre-compensation), quickly approaching the target light intensity range and shortening the adjustment delay of traditional pure feedback control. At the same time, the PID fine-tuning correction is performed based on the light intensity deviation value detected by the second light sensor 22, effectively eliminating adjustment errors caused by sudden changes in the reflectivity of the obstruction (such as changes in wall material) or environmental interference (such as temporary obstacles). For example, in a security camera scenario, when a suddenly approaching obstacle is detected (the distance shortens from 3m to 1m), the system can immediately reduce the current of the infrared light-emitting module 21 in the corresponding area to avoid instantaneous overexposure. At the same time, the PID algorithm maintains the stability of the remote fill light, demonstrating greater robustness in complex dynamic scenes (such as areas with dense traffic), balancing dimming speed and accuracy.

[0089] See also Figure 8 , step S42, further comprising:

[0090] Step S421: Acquire an ambient color temperature signal through the visible light detection channel of the multispectral sensor;

[0091] Step S422: detecting the reflected infrared light intensity through the infrared detection channel of the multispectral sensor;

[0092] Step S423: Calculating a color temperature compensation coefficient according to the ambient color temperature signal, and correcting the initial driving current based on the shortest distance and the color temperature compensation coefficient;

[0093] Step S424 : generating an adjustment current based on the corrected initial driving current and the current adjustment amount, and driving the adjustment current to each infrared light-emitting module 21 .

[0094] In steps S421 and S422, the multispectral sensor's visible light detection channel acquires the current ambient color temperature signal. Simultaneously, the multispectral sensor's infrared detection channel detects the intensity of reflected infrared light. This operation enables the monitoring device to simultaneously acquire two key parameters: ambient light color temperature and infrared reflected light intensity, providing richer information for subsequent precise fill light control.

[0095] In step S423, the main control board 20 uses a preset formula (such as ) calculates the color temperature compensation coefficient. Combined with the shortest distance detected by the ranging sensor, the main control board 20 uses this color temperature compensation coefficient to correct the initial drive current. This correction process comprehensively considers the impact of ambient color temperature on infrared fill light and the light intensity requirements of the obstruction distance, making the initial drive current more consistent with actual scene requirements, further improving the adaptability and accuracy of fill light control.

[0096] In step S423, after obtaining the corrected initial drive current and the current adjustment calculated based on the reflected light intensity deviation, the main control board 20 combines the two to generate a final adjusted current. This adjusted current is driven to each infrared light-emitting module 21 to precisely adjust its luminous intensity. In this way, the monitoring device can achieve precise control of the infrared light-emitting module 21 in complex environments based on multiple factors such as ambient color temperature, distance from obstructions, and reflected light intensity, ensuring that the light intensity received by the camera module 10 is always within the preset dynamic range, thereby obtaining high-quality, clear monitoring images.

[0097] Based on the above technical solution, precise control of the infrared light-emitting module 21 is achieved by comprehensively considering distance and color temperature factors. In actual application scenarios, the distance between the monitoring device and the obstruction and the color temperature of the ambient light can significantly affect the fill light effect. This method uses a ranging sensor to obtain the shortest distance between the monitoring device and the obstruction and generates an initial drive current based on this distance, ensuring the adaptability of the initial fill light intensity to the distance. At the same time, the ambient color temperature signal is obtained through the visible light detection channel of the multispectral sensor and a color temperature compensation coefficient is calculated to adjust the drive current of the infrared light-emitting module 21, effectively offsetting the impact of ambient color temperature changes on the fill light effect. For example, in low color temperature environments, infrared compensation is enhanced to overcome red light interference. Secondly, this method further optimizes the fill light effect through a feedback control mechanism. Based on the initial adjustment based on the initial drive current and the color temperature compensation coefficient, a current adjustment value is generated based on the deviation between the reflected light intensity detected by the second light sensor 22 and the preset dynamic range, achieving fine-grained regulation of the drive current. This composite control mode that combines feedforward control (distance prediction) with feedback control (light intensity correction) can not only quickly respond to changes in the distance of the obstruction and the ambient color temperature, but also ensure the accuracy of the fill light intensity, avoiding the delay or error problems that may occur in a single control method; finally, this method effectively solves the contradiction between near-end overexposure and far-end underexposure caused by a single light intensity adjustment in the prior art, enabling the monitoring device to automatically balance the fill light intensity of each area in a complex lighting environment, and independently control the driving current of the infrared light-emitting module 21 by region, and make targeted adjustments based on the reflected light intensity feedback of different areas, ensuring that the light intensity received by the camera module 10 is always within the preset dynamic range, thereby improving image quality and avoiding the loss of image details due to local overbrightness or darkness. It has significant beneficial effects in improving the quality of monitoring images, enhancing system adaptability and reliability, etc.

[0098] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's description and drawings, or direct / indirect applications in other related technical fields, within the scope of the present invention are included in the patent protection scope of the present invention.

Claims

1. A monitoring device, characterized in that: The monitoring device comprises: A camera module (10), the camera module (10) having a first light sensor; and A main control board (20), wherein the camera module (10) is provided on the main control board (20); the main control board (20) is provided with a plurality of infrared light-emitting modules (21) and at least one second light sensor (22), wherein the second light sensor (22) is configured to detect the light intensity of the reflected light and generate a corresponding electrical signal according to each light intensity, wherein each electrical signal corresponds to one infrared light-emitting module (21), and the main control board (20) adjusts the light intensity of the corresponding infrared light-emitting module (21) according to each electrical signal; The main control board (20) is further provided with a distance measuring sensor, which is configured to detect the shortest distance between the monitoring device and the obstruction and generate a distance electrical signal; the main control board (20) is further configured to calculate an initial driving current value corresponding to the infrared light emitting module (21) based on the distance electrical signal, and to adjust the initial driving current value based on the electrical signal generated by the second light sensor (22), so that the light intensity value received by the first light sensor is within a preset dynamic range.

2. The monitoring device according to claim 1, wherein: The mounting surface of the main control board (20) is arranged in a plane. The main control board (20) has N infrared light-emitting modules (21) and N second light sensors (22). The camera module (10) is arranged near the end of the mounting surface of the main control board (20). The N infrared light-emitting modules (21) are located on the mounting surface of the main control board (20) along a first height. The N second light sensors (22) are located on the mounting surface of the main control board (20) along a second height and below the infrared light-emitting modules (21). The N infrared light-emitting modules (21) and the N second light sensors (22) are arranged at intervals along a first direction. Each infrared light-emitting module (21) is arranged in alignment with one second light sensor (22).

3. The monitoring device according to claim 1, wherein: The main control board (20) is provided with a first mounting surface, a second mounting surface and a third mounting surface, the second mounting surface is located between the first mounting surface and the third mounting surface, and the second mounting surface is arranged at an angle to the first mounting surface and the third mounting surface; each mounting surface is provided with an infrared light-emitting module (21) and a second light sensor (22); the camera module (10) is arranged near the end of the mounting surface of the main control board (20), each infrared light-emitting module (21) is respectively located on the mounting surface corresponding to the main control board (20) along a first height, and each second light sensor (22) is located on the mounting surface of the main control board (20) along a second height and below the infrared light-emitting module (21); each infrared light-emitting module (21) and each second light sensor (22) are arranged at intervals along the first direction, and each infrared light-emitting module (21) is arranged in alignment with a second light sensor (22).

4. The monitoring device according to claim 1, wherein: The optical axis of the distance measuring sensor is arranged parallel to the light output axis of the corresponding infrared light emitting module (21), and the field of view angle of the distance measuring sensor covers the illumination area of ​​the infrared light emitting module (21).

5. The monitoring device according to claim 1, wherein: The second light sensor (22) is a multispectral sensor having at least one visible light detection channel and one infrared detection channel, wherein the visible light detection channel has a color temperature detection module, and the infrared detection channel is configured to detect the light intensity of the reflected light and generate a corresponding electrical signal according to the light intensity of each light; the main control board (20) is further configured to adjust the luminous intensity of the corresponding infrared light-emitting module (21) according to the color temperature signal of the visible light detection channel and the light intensity signal of the infrared detection channel.

6. The monitoring device according to claim 5, wherein: The visible light detection channel and the infrared detection channel are both equipped with narrow-band filters to separate reflection spectra of different wavelengths.

7. A method for adjusting overexposure of a monitoring device, used for the monitoring device according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: receiving a distance electrical signal from a distance measuring sensor, wherein the distance electrical signal is generated when the distance measuring sensor detects the shortest distance between the monitoring device and the obstruction; generating an initial driving current according to the distance electrical signal; Inputting an initial driving current to each infrared light emitting module (21); Acquiring a plurality of electrical signals generated by the reflected light intensity detected by the second light sensor (22) under the initial driving current, and determining whether the plurality of electrical signals are within a preset current range; When at least one of the electrical signals is not within a preset current range, obtaining a deviation value between the reflected light intensity of the second light sensor (22) and a preset dynamic range, and generating a current adjustment value according to the deviation value; An adjustment current is generated according to the initial driving current and the current adjustment amount, and the adjustment current is driven to each infrared light-emitting module (21), so that the light intensity value received by the first light sensor is within a preset dynamic range.

8. The overexposure adjustment method of the monitoring device according to claim 7, characterized in that: The method of generating an adjustment current based on the initial driving current and the current adjustment amount and driving the adjustment current to each infrared light-emitting module (21) includes: Acquire the ambient color temperature signal through the visible light detection channel of the multispectral sensor; detecting the reflected infrared light intensity through the infrared detection channel of the multispectral sensor; Calculating a color temperature compensation coefficient according to the ambient color temperature signal, and correcting the initial driving current based on the shortest distance and the color temperature compensation coefficient; An adjustment current is generated based on the corrected initial driving current and the current adjustment amount, and the adjustment current is driven to each of the infrared light-emitting modules (21).

Images