Camera multi-lens group focusing system and method based on deformable metal

Abstract

The invention discloses a camera multi-lens group focusing system and method based on deformable metal, relates to the technical field of camera modules, adopts the deformable metal as a focusing connecting piece to replace a traditional VCM motor, does not need a built-in magnet and coil, and effectively solves the problems that the VCM motor is large in size and occupies a large module space. The temperature of the deformable metal is controlled through the heating subsystem and the cooling subsystem to achieve accurate length change of the deformable metal, a mechanical driving mode of a VCM motor is replaced, mechanical noise generated during operation of the motor is avoided, meanwhile, power consumption is reduced, and the problem that the focusing precision is reduced due to mechanical abrasion after long-term use is also solved; compared with a liquid lens or MEMS micromotor alternative scheme, the cost of the deformable metal is easier to control, the driving force can meet the requirement, and the problem that the alternative scheme is high in cost or insufficient in driving force is solved, so that miniaturization, low noise, low power consumption and cost effectiveness of the camera are considered on the premise of ensuring the focusing performance.

Description

Technical Field

[0001] This invention relates to the field of camera module technology, and in particular to a camera multi-lens focusing system and method based on deformable metal. Background Technology

[0002] In the field of camera technology, focusing is a key element in ensuring clear imaging. For a long time, how to achieve efficient, low-noise and stable focusing within a limited module space has been a key research and development direction for the industry.

[0003] Currently, camera focusing primarily relies on a VCM (Voice Coil Motor) to drive the lens movement. However, this approach has significant limitations: firstly, the VCM motor requires built-in magnets and coils, resulting in a large overall size that occupies considerable module space, hindering the miniaturization and thinning of cameras; secondly, the motor generates mechanical noise during operation, affecting the user experience, and its high power consumption, coupled with the potential for decreased focusing accuracy due to mechanical wear over long-term use, contributes to this problem. Although existing technologies attempt to replace VCM motors with liquid lenses or MEMS (Micro-Electro-Mechanical Systems Motors), these alternatives either suffer from excessive cost or insufficient driving force, making widespread adoption in practical applications difficult. Therefore, camera focusing technology still faces pressing challenges in balancing performance, cost, and size. Summary of the Invention

[0004] This invention provides a camera multi-lens focusing system and method based on deformable metal, which solves the technical problems of traditional VCM motor focusing solutions being large in size and occupying a lot of module space due to built-in magnets and coils, and alternative solutions such as liquid lenses and MEMS micro motors having high costs or insufficient driving force.

[0005] The first aspect of the present invention provides a camera multi-lens focusing system based on deformable metal, comprising a core control module, a heating subsystem, a cooling subsystem, a physical model module, and a camera; The camera includes an image sensor and an adjustable focus lens group; The adjustable focus lens group includes at least two groups of lenses arranged sequentially along the optical axis; A focusing connector is provided between the two sets of lenses, and the two ends of the focusing connector are respectively connected to the two sets of lenses; The image sensor is used to calculate the target length of the focusing connector when it detects that the image clarity of the current scene image is lower than a preset defocus threshold. The core control module is used to perform PID control based on the detected current length of the focusing connector and the target length to generate a pulse width modulation value. The heating subsystem is used to convert the pulse width modulation value into a heating current and perform a heating operation on the focusing connector, and to record the heating time when the pulse width modulation value is greater than a preset modulation threshold. The cooling subsystem is used to make a cooling decision based on the current time of the focusing system and the surface temperature of the connector, combined with the current length, the target length and the heating time, and to perform a cooling start-stop operation on the focusing connector according to the cooling decision value; The physical model module is used to calculate the length change of the focusing connector based on the heating current and the cooling decision value, generate a new current length by combining the current length, and feed it back to the core control module. The focusing connector is used to generate mechanical deformation according to the new current length, change the axial distance between the two connected lens groups, and thereby adjust the equivalent focal length of the adjustable lens group.

[0006] Optionally, the camera also includes a housing and a lens mount; The mirror mount is provided at the bottom of the housing; The image sensor is mounted on the front end of the mirror mount; The image sensor has brackets on both sides for fixing the adjustable focus lens group. The bracket is connected to a fixed-distance connector, which is used to fix the position of a portion of the lens; The adjustable lens group is located between the fixed distance connector and the focusing connector.

[0007] Optionally, the focusing connector is made of a deformable metal material.

[0008] Optionally, the image sensor includes a defocusing degree quantization module, a defocusing and displacement calibration mapping module, and a length conversion module connected in sequence; The defocusing degree quantification module is used to determine the defocusing degree value by using the image clarity and the preset defocusing threshold when the image clarity of the current scene image is detected to be lower than the preset defocusing threshold. The defocus and displacement calibration mapping module is used to determine the lens displacement based on the preset defocus and displacement calibration mapping relationship and the defocus degree value. The length conversion module is used to perform a summation operation between the initial length of the focusing connector and the lens displacement to obtain the target length of the focusing connector within the adjustable lens group.

[0009] Optionally, the core control module includes a length deviation unit and a PID control unit that are interconnected; The length deviation unit is used to perform a difference calculation based on the detected current length of the focusing connector and the target length to obtain a length deviation value. The PID control unit is used to generate a pulse width modulation value by inputting a preset PID control function based on the length deviation value.

[0010] Optionally, the heating subsystem includes a current mapping module, a heating control module, and a time recording module connected in sequence; The current mapping module is used to input the pulse width modulation value into a preset current conversion function to generate a heating current; The heating control module is used to perform a heating operation on the focusing connector using the heating current; The time recording module is used to record the heating time when the pulse width modulation value is greater than a preset modulation threshold.

[0011] Optionally, the cooling subsystem includes a data acquisition module, a cooling decision module, and a cooling control module connected in sequence; The data acquisition module is used to acquire the current time of the focusing system and the surface temperature of the connector; The cooling decision module is used to determine whether the current focusing system meets the preset cooling start-up conditions based on the current time, the surface temperature of the connector, the current length, the target length, the heating time, and the preset length change value. If satisfied, the first preset value associated with the cooling start operation will be used as the cooling decision value. If the condition is not met, the second preset value associated with the cooling pause operation will be used as the cooling decision value. The cooling control module is used to perform a cooling start operation or a cooling pause operation on the focusing connector based on the cooling decision value.

[0012] Optionally, the physical model module includes a heating effect unit, a cooling effect unit, a length change unit, and a length update unit connected in sequence; The heating effect unit is used to generate a heating effect value based on the heating current; The cooling effect unit is used to generate a cooling effect value based on the cooling decision value; The length change unit is used to input the heating effect value and the cooling effect value into a preset length change function to generate a length change amount; The length update unit is used to perform a summation operation between the length change and the current length to generate a new current length, and then feed it back to the core control module.

[0013] Optionally, it may also include a security monitoring module; The safety monitoring module is used to monitor the surface temperature of the connector and the heating current in real time. When the surface temperature of the connector is greater than a preset surface temperature threshold or the heating current is greater than a preset heating current threshold, the heating subsystem is cut off, the cooling subsystem is started, and an alarm is output.

[0014] A second aspect of the present invention provides a method for applying the aforementioned camera multi-lens focusing system based on deformable metal, comprising: When the image sharpness of the current scene is detected to be lower than the preset defocus threshold, the target length of the focusing connector is calculated. Based on the detected current length of the focusing connector, PID control is performed in conjunction with the target length to generate a pulse width modulation value; The pulse width modulation value is converted into a heating current and a heating operation is performed on the focusing connector. The heating time when the pulse width modulation value is greater than the preset modulation threshold is recorded. Based on the current time of the focusing system and the surface temperature of the connector, a cooling decision is made in combination with the current length, target length and heating time, and a cooling start-stop operation is performed on the focusing connector according to the cooling decision value; The length change of the coking connector is calculated based on the heating current and cooling decision value, and a new current length is generated by combining the current length and fed back to the core control module. The mechanical deformation generated by the new current length changes the axial distance between the two connected lens groups, thereby adjusting the equivalent focal length of the adjustable lens group.

[0015] As can be seen from the above technical solutions, the present invention has the following advantages: This invention provides a camera multi-lens focusing system and method based on deformable metal. First, deformable metal is used as the focusing connector to replace the traditional VCM motor, eliminating the need for built-in magnets and coils, effectively solving the problems of large size and large module space occupation of VCM motors. Second, the temperature of the deformable metal is controlled by heating and cooling subsystems to achieve precise length changes, replacing the mechanical drive method of VCM motors, avoiding mechanical noise generated during motor operation, reducing power consumption, and solving the problem of decreased focusing accuracy due to mechanical wear over long-term use. Furthermore, compared to liquid lenses or MEMS micro-motors, the cost of deformable metal is easier to control, and the driving force can meet the requirements, solving the dilemma of high cost or insufficient driving force of these alternatives. Thus, while ensuring focusing performance, it also considers camera miniaturization, low noise, low power consumption, and cost-effectiveness. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural block diagram of a camera multi-lens focusing system based on deformable metal according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the cooperation structure between the focusing connector and the adjustable lens group according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a conventional VCM motor module structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a conventional lens fixing structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the adjustable focus lens group according to an embodiment of the present invention; Figure 6 This is a control logic block diagram of the current-deformation-focal length change according to an embodiment of the present invention; Figure 7 This is a flowchart illustrating the steps of a focusing method applied to a camera multi-lens focusing system based on deformable metal, according to an embodiment of the present invention. Figure 8 This is a flowchart of the main loop of the system according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the circuit connection of the Arduino control board according to an embodiment of the present invention. Detailed Implementation

[0018] This invention provides a camera multi-lens focusing system and method based on deformable metal. By replacing the traditional VCM motor with deformable metal, focusing is achieved by directly adjusting the lens spacing. This solution significantly reduces module size, eliminates noise, and lowers power consumption, making it suitable for ultra-thin camera designs. It aims to address the shortcomings of traditional VCM motor focusing solutions, such as large size, the need for magnetic components, high noise, and high power consumption.

[0019] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] Please see Figure 1 and Figure 2 The present invention provides a camera multi-lens focusing system based on deformable metal, including a core control module, a heating subsystem, a cooling subsystem, a physical model module and a camera; The camera includes an image sensor and a focusable lens assembly; The adjustable focus lens group includes at least two groups of lenses arranged sequentially along the optical axis; A focusing connector is provided between the two sets of lenses, and the two ends of the focusing connector are respectively connected to the two sets of lenses; An image sensor is used to calculate the target length of the focusing connector when the image sharpness of the current scene is detected to be lower than a preset defocus threshold. The core control module is used to perform PID control based on the detected current length of the focusing connector and the target length to generate pulse width modulation values; The heating subsystem is used to convert the pulse width modulation value into a heating current and perform a heating operation on the focusing connector, and to record the heating time when the pulse width modulation value is greater than a preset modulation threshold. The cooling subsystem is used to make cooling decisions based on the current time of the focusing system and the surface temperature of the connector, combined with the current length, target length and heating time, and to perform cooling start and stop operations on the focusing connector according to the cooling decision value; The physical model module is used to calculate the length change of the coking connector based on the heating current and cooling decision value, generate a new current length by combining the current length, and feed it back to the core control module; A focusing connector is used to generate mechanical deformation according to the new current length, change the axial distance between the two connected lens groups, and thus adjust the equivalent focal length of the adjustable lens group.

[0021] Deformable metal: refers to a metallic material that can produce stable and recoverable mechanical deformation in response to changes in external conditions (such as temperature and electric field). In this invention, it specifically refers to a shape memory alloy (SMA) made of nickel-titanium alloy, which can achieve elongation or contraction through temperature changes and is used to transmit power to adjust the lens spacing.

[0022] Adjustable focus lens group: refers to an optical assembly consisting of at least two groups of lenses arranged sequentially along the optical axis, with some lenses movable along the optical axis. By changing the axial distance between the movable lens and the fixed lens, the equivalent focal length of the entire lens group can be adjusted to achieve the focusing function.

[0023] Focusing connector: refers to a structural component that connects two lenses in an adjustable focusing lens group and has the ability to deform. In this invention, it is a wire or sheet made of nickel-titanium alloy, which is used to drive the two lenses to move through its own deformation and change the lens spacing.

[0024] PID control: Proportional-Integral-Derivative control, is a closed-loop control algorithm that generates a control signal (PWM value) by calculating the deviation (proportional term) between the setpoint (target length) and the actual value (current length), the cumulative value of the deviation (integral term), and the rate of change of the deviation (derivative term), thereby achieving precise control of the controlled object (length of the focusing connector).

[0025] Pulse Width Modulation (PWM) value: refers to the value of the control quantity expressed by adjusting the duty cycle of the high level time of the pulse signal. The range is usually 0-255. In this invention, it is used to control the heating current of the heating subsystem, and thus control the heating intensity of the focusing connector.

[0026] Cooling decision value: refers to the control status indicator of the cooling subsystem for the cooling device (cooling fan), with a value of 1 or 0. 1 indicates that the cooling device is started and 0 indicates that the cooling device is turned off. It is used to reflect the cooling requirements of the coking connector.

[0027] Equivalent focal length: refers to the focal length when a multi-lens group is equivalent to a single lens. It is a core parameter for measuring the imaging capability of a lens group. In this invention, by changing the axial distance between the two lens groups, the equivalent focal length of the lens group is adjusted to achieve clear imaging (i.e., focusing) of objects at different distances.

[0028] Preset defocus threshold: refers to the sharpness threshold at which the image sensor determines whether an image is out of focus. It is set based on the camera application scenario (such as front-facing selfie, rear-facing distant shooting). When the sharpness is lower than this threshold, the system starts the focusing process.

[0029] In the embodiments of the present invention, please refer to Figure 2The adjustable lens group can specifically adopt four sets of spherical lenses arranged sequentially along the optical axis, such as the first lens, the second lens, the third lens, and the fourth lens. The two ends of the focusing connector are rigidly connected to the lens mounts of the third lens and the fourth lens, respectively, to ensure that the deformation of the focusing connector can be directly transmitted to the two sets of lenses to change the axial spacing. The focusing connector is preferably made of shape memory alloy (SMA) wire or sheet made of nickel-titanium alloy, which has the characteristic of producing stable mechanical deformation with temperature change. It is in an initial contracted state at room temperature, can be stretched along the optical axis after being heated, and returns to contraction after cooling, so as to meet the needs of dynamic adjustment of lens spacing. When the camera is activated, the image sensor acquires the current scene image in real time and calculates the image sharpness using a contrast algorithm. If the sharpness is lower than the preset defocus threshold, which can be set according to the camera application scenario (e.g., the preset threshold for a front-facing camera is 80, and for a rear high-definition camera it is 90), the image sensor calculates the target length based on the mapping relationship between the degree of defocus and the length of the focusing connector, and sends the target length to the core control module. The core control module first obtains the current length of the focusing connector through the displacement sensor, and then executes the PID control algorithm with the current length as the input value and the target length as the set value. The proportional coefficient Kp of the PID controller is set to 0.8, the integral coefficient Ki is set to 0.2, and the derivative coefficient Kd is set to 0.1. The pulse width modulation value, or PWM value, is generated by calculating the deviation and the rate of change of the deviation, ranging from 0 to 255, and the PWM value is sent to the heating subsystem. After receiving the PWM value, the heating subsystem converts it into a corresponding heating current through a current conversion circuit and outputs the heating current to the two electrodes of the focusing connector to heat the connector. Simultaneously, the heating subsystem has a built-in timer that records the current heating time (i.e., the timestamp of the last effective heating) when the detected PWM value exceeds a preset modulation threshold. The cooling subsystem, on the other hand, collects the surface temperature of the focusing connector in real time using a temperature sensor and obtains the current time via the system clock. It then combines this information with the current length of the focusing connector, the target length, and the heating time recorded by the heating subsystem, synchronized with the core control module, to make cooling decisions: when the current length of the focusing connector is greater than the target length + 0.1 mm (contraction detection threshold) and the difference between the current time and the heating time is greater than 500 ms (cooling delay time), or when the surface temperature of the focusing connector is greater than 30°C (cooling start temperature threshold), the cooling subsystem outputs a high-level control signal to activate the cooling device, such as a miniature cooling fan, to actively cool the focusing connector; otherwise, it shuts down the cooling fan and sends the cooling decision value (1 for activation, 0 for deactivation) to the physical model module.The physical model module calculates the length change of the focusing connector based on the actual heating current fed back by the heating subsystem and the cooling decision value fed back by the cooling subsystem: first, it calculates the heating effect (value 0-1, reflecting the heating intensity) and the cooling effect (C=0.15 when cooling starts and C=0.02 when cooling is natural), then calculates the length change through the length change function, and then adds the length change to the current length of the focusing connector to generate a new current length, which is fed back to the core control module through the data interface to form a closed-loop control. The focusing connector undergoes real-time mechanical deformation based on the new current length: when the new current length is greater than the current length, the focusing connector expands due to heat, pushing the third and fourth lenses to move in opposite directions along the optical axis, increasing the axial distance between the two lens groups; when the new current length is less than the current length, the focusing connector contracts due to cooling, pulling the third and fourth lenses to move towards each other along the optical axis, decreasing the axial distance between the two lens groups; the change in the axial distance between the lenses changes the equivalent focal length of the adjustable lens group, thereby enabling the camera to focus, until the image sensor detects that the image sharpness reaches or exceeds the preset defocus threshold, at which point the system enters focus hold mode.

[0030] It should be noted that, as Figure 2 As shown, this invention features a deformable metal connection structure, reducing the need for permanent magnet / coil drive. The innovative design incorporates a deformable metal connection structure at the lens-to-lens connection point within the lens assembly. Focusing is achieved by applying voltage and utilizing the material's deformation properties to change the distance between lenses. It should be noted that you should refer to [link / reference]. Figure 3 , Figure 3 This diagram illustrates the structure of a traditional VCM motor module. In a traditional VCM motor module, changing the focal length requires energizing a coil to convert electrical energy into magnetic force, which in turn moves a permanent magnet and the entire lens assembly associated with the permanent magnet to achieve focusing. This structure relies on components such as coils and permanent magnets, which not only makes the module larger and occupies more space to accommodate these components, but also generates noise during operation due to the mechanical movement of the components. Furthermore, long-term mechanical friction can lead to a decrease in focusing accuracy, and the overall power consumption is relatively high.

[0031] Please see Figure 4 , Figure 4 This diagram illustrates a traditional lens fixing structure. In a traditional lens fixing structure, such as a module lens composed of four lenses, a fixed inter-lens connector is used to connect the lenses, keeping their relative positions fixed. With this structure, the lens spacing cannot be adjusted according to imaging requirements, making focusing difficult. Fixed optical parameters must be pre-set during production, limiting its applicability. Compared to the system of this invention, which is based on deformable metal and can dynamically adjust lens spacing to achieve focusing, it has a significant gap in flexibility and focusing capability.

[0032] Please see Figure 5 The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the camera also includes a housing and a lens mount; A mirror mount is provided at the bottom of the housing; An image sensor is mounted on the front end of the mirror mount; The image sensor has brackets on both sides for fixing the adjustable focus lens group. The bracket is connected to a fixed-distance connector, which is used to fix the position of part of the lens; The adjustable lens group is located between the fixed distance connector and the focusing connector.

[0033] Lens: An optical element that makes up an adjustable lens group. It changes the light path by refracting light. Multiple lenses work together to achieve imaging and focusing.

[0034] Focusing connector: Made of deformable metal material (such as shape memory alloy), it can move the lens through its own deformation and adjust the lens spacing to achieve focusing.

[0035] Frame mount: A component that provides a mounting base and support for the various internal parts of the camera, ensuring the stability of each component's position.

[0036] Image sensor: Used to receive light after it has been refracted by a lens group, convert the light signal into an electrical signal, and then generate image data.

[0037] Support: Mounted on the lens mount, used to fix other components (such as fixed distance connectors, etc.) and ensure the stability of the entire optical structure.

[0038] Fixed-distance connector: Connected to the bracket, it is used to fix the position of some lenses, so that these lenses maintain a relatively stable spacing, and provides a basis for the focusing connector to adjust the position of other lenses.

[0039] In embodiments of the present invention, such as Figure 5 As shown, 1 represents the lens, 2 represents the focusing connector, 3 represents the lens mount, 4 represents the image sensor, 5 represents the bracket, and 6 represents the fixed-distance connector. The lens mount, as the basic supporting component, is fixed to the bottom of the housing. The image sensor is mounted on the lens mount and is used to receive light refracted by the lens to complete the image formation. The bracket is located on both sides of the image sensor, serving a supporting and positioning function. The bracket is connected to the fixed-distance connector, which is used to fix the position of part of the lens, keeping this part of the lens stable. The lens in the adjustable lens group is located between the fixed-distance connector and the focusing connector. The focusing connector is made of a deformable metal material and can move the lens connected to it through its own deformation, changing the axial distance between the lenses, thereby adjusting the equivalent focal length of the adjustable lens group and realizing the focusing function.

[0040] Please see Figure 2 The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the focusing connector is made of deformable metal material.

[0041] In this embodiment of the invention, deformable metallic materials include shape memory alloys, electrostrictive metals, liquid metals, and superplastic metals. Shape memory alloys, represented by nickel-titanium alloys, copper-based shape memory alloys, and iron-based shape memory alloys, are used in the medical, aerospace, and electronic equipment fields to manufacture various functional components that automatically recover their shapes, thanks to their unique shape memory effect. Among electrostrictive metals, piezoelectric ceramic-metal composites and giant magnetostrictive materials deform under the influence of electric and magnetic fields, respectively, and are widely used in applications requiring high precision and response speed, such as precision positioning, ultrasonic transducers, and hydraulic valve actuations.

[0042] Liquid metals, such as gallium indium tin alloys, are emerging in electronic device manufacturing due to their liquid properties at room temperature and their good conductivity and fluidity, especially in fields with high requirements for deformation adaptability, such as flexible circuits. Superplastic metals, such as aluminum alloys and titanium alloys under specific conditions, can achieve high-precision forming of complex parts in industrial production such as aerospace component manufacturing by utilizing their extraordinary plastic deformation capabilities, thereby optimizing manufacturing processes and reducing production costs.

[0043] In specific implementations, such as Figure 2 As shown, a four-element lens group is used, with the outermost third and fourth lenses connected by a focusing connector made of shape memory alloy (such as nickel-titanium alloy). Structurally, the third and fourth lenses are connected by a shape memory alloy (nickel-titanium alloy) support, designed in a U-shape. When focusing is required, a specific current is applied to the focusing connector. Utilizing the thermal deformation properties of the shape memory alloy, the originally U-shaped support deforms due to the heat generated by the current, elongating from a U-shape to an I-shape. This causes the third lens to shift, directly changing the distance between the third and fourth lenses, thereby adjusting the equivalent focal length of the entire lens group and achieving optical focusing. During cooling, the focusing connector made of shape memory alloy (such as nickel-titanium alloy) gradually shrinks as the temperature decreases. The support structure, which originally stretched into an I-shape due to heating, returns to its initial U-shape. This transformation from I-shape to U-shape pulls the third lens towards the fourth lens, reducing the distance between the two lens groups and thus adjusting the equivalent focal length of the lens group. This creates a reverse linkage with the stretching process from U-shape to I-shape during heating, achieving precise control of the lens spacing through bidirectional shape changes, ensuring the stability and accuracy of focus adjustment.

[0044] The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the image sensor includes a defocusing degree quantization module, a defocusing and displacement calibration mapping module and a length conversion module connected in sequence. Image sensor: The core component in a camera that converts light signals into electrical signals. It has built-in modules for defocus detection and target length calculation, and can analyze image sharpness in real time and output the target length parameters required for focusing. Defocus Quantification Module: A sub-module within the image sensor used to determine the severity of defocus. It calculates the defocus level by comparing the current image sharpness with a preset defocus threshold, thus quantifying the defocus state of the image. Defocus and displacement calibration mapping module: A sub-module that pre-stores experimental calibration mapping relationships within the image sensor. After receiving the defocus degree value, it matches and outputs the lens displacement amount required to achieve clear imaging, establishing the correlation between the defocus state and the mechanical adjustment amount. Length conversion module: A sub-module within the image sensor used to calculate the target length of the focusing connector. Combining the initial length of the focusing connector with the lens displacement, it converts the optical adjustment requirements into a specific length target for the focusing connector. Image sharpness: An imaging quality parameter obtained through contrast algorithms (such as the Sobel operator to calculate edge contrast), with a value range of 0-100. The higher the value, the sharper the image edges and the richer the details.

[0045] Preset defocus threshold: A pre-set critical value for determining whether an image is out of focus. It is adjusted according to the camera application scenario (such as front-facing selfie, rear-facing distant view). When the image is below this threshold, the focusing process is initiated.

[0046] Defocus severity value: A parameter that quantifies the severity of defocus, ranging from 0 to 1. It is calculated based on the percentage deviation between the current image sharpness and the preset defocus threshold, and is used to correlate the required lens displacement. Lens displacement: The distance that the lens in the adjustable lens group needs to be moved to achieve clear imaging. It is obtained by matching the defocusing degree value through a pre-stored mapping relationship and is a key parameter for calculating the target length of the focusing connector. Initial length of focusing connector: The natural length of a deformable metal at room temperature (such as nickel-titanium alloy SMA wire) is used as the reference value for calculating the target length and needs to be preset according to the lens assembly installation dimensions. Target length of focusing connector: The final length that the focusing connector needs to reach is obtained by summing the initial length and the lens displacement, and is used to guide the core control module in generating subsequent heating and cooling control signals.

[0047] The defocusing degree quantification module is used to determine the defocusing degree value by comparing the image sharpness with the preset defocusing threshold when the image sharpness of the current scene is detected to be lower than the preset defocusing threshold. In this embodiment of the invention, the defocusing degree quantification module built into the image sensor first collects the image sharpness of the current scene in real time, calculates it using a contrast algorithm, with a value ranging from 0 to 100. A higher value indicates a sharper image. This value is then compared with a preset defocusing threshold, which is set to 90 for mobile phone rear camera scenarios. When the current image sharpness is detected to be lower than the preset defocusing threshold, the defocusing degree quantification module determines the defocusing degree value by calculating the percentage deviation between the current image sharpness and the preset defocusing threshold. The specific formula is as follows:

[0048] In the formula, This value indicates the degree of focus distortion, ranging from 0 to 1. A higher value indicates a more severe focus distortion. This indicates the preset defocus threshold. This indicates the image clarity of the current scene.

[0049] The defocus and displacement calibration mapping module is used to determine the amount of lens displacement based on the preset defocus and displacement calibration mapping relationship and the degree of defocus. In this embodiment of the invention, the core of the defocus and displacement calibration mapping module is to establish a preset calibration mapping relationship of "defocus degree value - lens displacement amount" through preliminary experiments. This relationship needs to be customized for the application scenario of the camera: In the experimental stage, the camera is first fixed on a standard test platform, and standard target images with different defocus states are taken in sequence, with the defocus degree increasing in a gradient from 0% to 50%. The image sharpness is calculated for each target image. Defocusing value Simultaneously, a high-precision laser displacement sensor is used to measure the distance the lens needs to move to restore the target image to clarity (i.e., the amount of lens displacement). After multiple experimental calibrations, a linear mapping relationship was obtained. and They are directly proportional, and the specific formula is:

[0050] In the formula, Indicates the amount of lens displacement. This represents the calibration coefficient.

[0051] The length conversion module is used to perform a summation operation between the initial length of the focusing connector and the lens displacement to obtain the target length of the focusing connector within the adjustable lens group.

[0052] In this embodiment of the invention, before receiving the lens displacement from the defocusing and displacement calibration mapping module, the length conversion module pre-stores the initial length of the focusing connector. This initial length is the natural length of a deformable metal (such as a nickel-titanium alloy SMA wire) at room temperature (25°C) when it is not under stress or heated. It needs to be determined in conjunction with the installation dimensions of the adjustable lens group. In this embodiment, since the initial distance between the third and fourth lenses is 2.0 mm, the initial length of the focusing connector is set to 2.0 mm. When the module receives the lens displacement, it uses the initial length of the focusing connector as a reference and converts the lens displacement into the target length that the focusing connector needs to achieve through a summation operation. The specific formula is as follows:

[0053] In the formula, This indicates the target length of the focusing connector, in mm. This indicates the initial length of the focusing connector.

[0054] The present invention provides a camera multi-lens focusing system based on deformable metal, the core control module of which includes an interconnected length deviation unit and a PID control unit; The length deviation unit is used to perform a difference calculation based on the detected current length of the focusing connector and the target length to obtain the length deviation value; Core control module: The control center of the focusing system. It generates the pulse width modulation value required for focusing through length deviation calculation and PID control, and coordinates various subsystems to achieve precise control of the length of the focusing connector.

[0055] Length Deviation Unit: A sub-unit in the core control module used to calculate the difference between the current length and the target length of the focusing connector. It quantifies the focusing deviation through difference calculation and provides input parameters for PID control.

[0056] In this embodiment of the invention, the length deviation unit of the core control module first obtains the current length of the focusing connector in real time through a displacement sensor (such as a micro grating displacement sensor), which is the actual length of the deformable metal at the current temperature; simultaneously, the unit receives the target length of the focusing connector transmitted by the length conversion module, and then calculates the length deviation value through difference calculation, the specific formula being:

[0057] In the formula, This indicates the length deviation value. This indicates the current length of the focusing connector.

[0058] The PID control unit is used to generate pulse width modulation values ​​based on the input of a preset PID control function according to the length deviation value.

[0059] PID control unit: A sub-unit in the core control module that generates pulse width modulation values ​​based on the proportional-integral-derivative algorithm. By combining the current deviation, the cumulative historical deviation, and the deviation change trend, it outputs a precise control signal to achieve stable control of the length of the focusing connector.

[0060] In this embodiment of the invention, after receiving the length deviation value transmitted by the length deviation unit, the PID control unit inputs it into a preset PID control function for calculation. This function generates a pulse width modulation value through the coordinated action of proportional, integral, and derivative terms to achieve precise closed-loop control of the length of the focusing connector. The expression of the preset PID control function is as follows:

[0061] In the formula, Indicates the pulse width modulation value. Represents the proportionality coefficient. Represents the integral coefficient. Represents the differential coefficient. The integral term representing the deviation value, The differential term represents the deviation value.

[0062] The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the heating subsystem includes a current mapping module, a heating control module and a time recording module connected in sequence; The current mapping module is used to input the pulse width modulation value into a preset current conversion function to generate a heating current. Current mapping module: This submodule in the heating subsystem is responsible for converting pulse width modulation values ​​into heating current. It achieves linear mapping between the two through a preset current conversion function, ensuring precise matching between heating intensity and control signal.

[0063] Preset current conversion function: A pre-defined mathematical relationship between pulse width modulation value and heating current. The upper and lower limits of the current are set based on the thermal characteristics of deformable metals to ensure that the heating effect is controllable and safe.

[0064] Heating current: The current generated by the current mapping module is used to heat the focusing connector (deformable metal). Its magnitude directly affects the temperature change rate and deformation amplitude of the deformable metal.

[0065] Minimum heating current: The preset lower limit of heating current ensures that sufficient heat can still be provided to deformable metals to initiate deformation in low-temperature environments, avoiding focusing failure due to insufficient current.

[0066] Maximum heating current: The preset upper limit of heating current to prevent damage to deformable metals due to excessive heating caused by excessive current, and to ensure the safe operation of the system.

[0067] Pulse width modulation value: The signal value output by the core control module to control the heating intensity, ranging from 0 to 255. The larger the value, the greater the heating current and the higher the heating intensity.

[0068] In this embodiment of the invention, the current mapping module pre-stores a preset current conversion function. This function, based on the thermal response characteristics of deformable metals (such as nickel-titanium alloys), linearly converts the pulse width modulation value (PWM value, range 0-255) output by the core control module into the corresponding heating current, ensuring a precise match between heating intensity and focusing requirements. Considering material safety and deformation efficiency, the minimum heating current is set to 25mA (to ensure deformation can be initiated at low temperatures), and the maximum heating current is set to 100mA (to avoid overheating leading to material performance degradation). The specific formula is as follows:

[0069] In the formula, Indicates heating current. Indicates the minimum heating current. This indicates the maximum heating current.

[0070] The heating control module is used to perform heating operations on the focusing connector using heating current; Heating control module: The sub-module in the heating subsystem responsible for performing the heating operation. It outputs the heating current stably to the focusing connector through the drive circuit, thereby achieving precise temperature control and driving deformation.

[0071] MOSFET drive circuit: The core circuit in the heating control module, which uses a metal-oxide-semiconductor field-effect transistor (MOSFET) as the switching element, can quickly respond to control signals and realize precise output and on / off control of heating current.

[0072] Joule's Law describes the law of heat generation when an electric current passes through a conductor. It states that the square of the current, the conductor's resistance, and the time the current flows equal the heat generated. It is the physical basis for the heating of the focusing connector.

[0073] Heating power (P): The heat generated by the focusing connector per unit time is determined by the heating current and its own resistance, and directly affects the rate of temperature rise and deformation response speed.

[0074] Sampling resistor: A high-precision resistor (0.1Ω precision resistor is used in series in the heating circuit) is used to calculate the actual heating current by measuring the voltage, so as to realize closed-loop monitoring of the current.

[0075] Electrodes: Conductive contacts (usually made of copper) located at both ends of the focusing connector, used to connect the heating current and ensure that the current flows evenly through the deformable metal material.

[0076] In this embodiment of the invention, after receiving the heating current from the current mapping module, the heating control module stably outputs the current to the two electrodes of the focusing connector through its internal MOSFET driving circuit. This utilizes Joule's law to convert electrical energy into heat energy, thereby raising the temperature of the focusing connector. Its heating power follows the formula:

[0077] In the formula, This indicates the heating power of the focusing connector. The resistance of the focusing connector is indicated; in this embodiment, the resistance of the nickel-titanium alloy wire is 5Ω.

[0078] Please see Figure 6 , Figure 6 This flowchart illustrates the process of the heating control module driving the deformation of the focusing connector, clearly demonstrating the complete process of "applied voltage → deformation of the shape memory metal → increase in lens spacing → change in focal length." When the heating control module receives the heating current from the current mapping module, its internal MOSFET drive circuit responds quickly, using the MOSFET as the core switching element to stably output the heating current to the two electrodes of the focusing connector (nickel-titanium alloy wire). At this point, according to Joule's law, the focusing connector begins to generate heat, and the heating power directly determines its temperature rise rate. A 0.1Ω sampling resistor connected in series in the heating circuit monitors the actual heating current in real time, ensuring the current output accuracy is within ±1mA, achieving closed-loop current monitoring. As the temperature of the focusing connector rises, it undergoes elongation deformation based on the shape memory effect, which in turn pushes the corresponding lens in the lens group to move, increasing the lens spacing and ultimately causing a change in the camera's focal length, completing the focusing adjustment process.

[0079] The time recording module is used to record the heating time when the pulse width modulation value is greater than the preset modulation threshold.

[0080] In this embodiment of the invention, the time recording module works synchronously with the heating control module. It internally stores a preset modulation threshold, preferably 50, to match the effective heating threshold of the focusing connector. When it receives the pulse width modulation (PWM) value from the core control module, it determines in real time whether the value is greater than the preset modulation threshold. If the PWM value is 60 (greater than 50), the module immediately triggers the timing function, records the current heating start time (e.g., t1=10:00:00.200) using the system clock, and continuously monitors the PWM value status until the PWM value drops to 50 or below. Then, it records the heating end time (e.g., t2=10:00:00.800), and obtains the single effective heating time (Δt=t2-t1=0.6 seconds) through difference calculation. Simultaneously, it stores the timestamp and heating duration in the internal cache. If the PWM value is 40 (less than 50), it is determined to be ineffective heating, and the module does not start the timing, only recording the current PWM value status. The recorded heating time will be synchronized to the cooling subsystem in real time, providing a historical heating duration reference for cooling decisions, ensuring that the cooling operation matches the heating intensity, and avoiding excessive deformation of the coking connector due to continuous high temperature.

[0081] The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the cooling subsystem includes a data acquisition module, a cooling decision module and a cooling control module connected in sequence; The data acquisition module is used to acquire the current time of the focusing system and the surface temperature of the connector. In this embodiment of the invention, the data acquisition module of the cooling subsystem is synchronized with the system clock in real time to acquire the current time of the focusing system with millisecond-level accuracy. Simultaneously, it continuously collects the surface temperature of the focusing connector using an NTC thermistor attached to the connector surface; this temperature directly reflects the real-time thermal state of the focusing connector. The module filters the acquired current time and connector surface temperature, and then synchronizes them to the cooling decision module via the internal data bus. To ensure data timeliness, a sampling period of 10ms is set to ensure that the cooling decision can respond promptly to temperature changes in the focusing connector.

[0082] The cooling decision module is used to determine whether the current focusing system meets the preset cooling start conditions based on the current time, the surface temperature of the connector, the current length, the target length, the heating time, and the preset length change value. Cooling Decision Module: The core module in the cooling subsystem that determines whether to start cooling. By integrating multi-dimensional parameters such as time, temperature, and length, it decides on the cooling operation based on preset conditions to ensure the stability of the temperature and length of the focusing connector.

[0083] Preset cooling start conditions: Pre-set criteria for starting cooling, taking into account parameters such as temperature, length deviation, and time interval, to avoid unnecessary cooling operations and balance focusing efficiency and system power consumption.

[0084] Preset length variation value: The maximum allowable deviation between the length of the focusing connector and the target length. It is used to determine whether the length is close to the target length and to avoid premature cooling during focusing, which could affect deformation accuracy.

[0085] Cooling start temperature threshold: The lowest surface temperature value that triggers cooling (30°C in this embodiment). Below this value, the temperature of the focusing connector is within a safe range and no cooling is required.

[0086] Cooling delay threshold: The shortest time interval between the end of heating and the start of cooling (300ms in this embodiment) to avoid misjudgment caused by the temperature not being stable immediately after heating ends.

[0087] Cooling decision value: The judgment result output by the cooling decision module. It is usually represented by 1 to indicate that the cooling start condition is met and 0 to indicate that it is not met. It is used to control the operation of the cooling control module.

[0088] In this embodiment of the invention, the cooling decision module receives the current time and the surface temperature of the connector transmitted by the data acquisition module, and simultaneously acquires the current length and target length of the focusing connector from the core control module, as well as the heating time from the heating subsystem time recording module, and calls the pre-stored preset length change value (set to 0.05mm in this embodiment, representing the allowable length deviation range).

[0089] The module integrates these parameters to determine whether the preset cooling start-up conditions are met: When the surface temperature of the connector is >30℃ (cooling start temperature threshold), and the absolute value of the difference between the current length and the target length is ≤ the preset length change value (0.05mm, i.e., close to the target length), and the interval between the current time and the heating end time is >300ms (cooling delay threshold), the cooling start condition is deemed met; if any condition is not met, it is deemed not met. The determination result will serve as the basis for generating the cooling decision value, directly affecting the start and stop of subsequent cooling operations.

[0090] If satisfied, the first preset value associated with the cooling start operation will be used as the cooling decision value. If the condition is not met, the second preset value associated with the cooling pause operation will be used as the cooling decision value. Cooling decision value: The binary status value output by the cooling decision module to control the cooling operation. It is associated with the cooling start or pause operation through preset values ​​and is the core input parameter of the cooling control module.

[0091] First preset value: A preset value (1) bound to the cooling start operation. It is output when the cooling start condition is met, and is used to trigger the cooling control module to perform the cooling action.

[0092] Second preset value: A preset value (0 in this embodiment) bound to the cooling pause operation. It is output when the cooling start condition is not met, and is used to instruct the cooling control module to maintain standby state.

[0093] Cooling start-up operation: The cooling subsystem activates the cooling device (such as a micro fan or semiconductor refrigeration chip) to lower the temperature of the focusing connector and stabilize it at the thermal state corresponding to the target length.

[0094] Cooling pause operation: This refers to the action of stopping or not starting the cooling device in the cooling subsystem. It is applicable to scenarios where the temperature of the focusing connector is within a safe range or the focusing process has not been completed, in order to avoid affecting the deformation process.

[0095] In this embodiment of the invention, after determining the preset cooling start conditions, the cooling decision module generates a corresponding cooling decision value based on the determination result: if the cooling start conditions are met, the first preset value associated with the cooling start operation (set to "1" in this embodiment) is used as the cooling decision value, which represents that the cooling mechanism should be started immediately; if the cooling start conditions are not met, the second preset value associated with the cooling pause operation (set to "0" in this embodiment) is used as the cooling decision value, which represents maintaining the current state and not starting the cooling. The generated cooling decision value ("1" or "0") is transmitted to the cooling control module in real time, directly determining the operating state of the cooling device, ensuring that the cooling operation is only started when necessary, thus avoiding the performance of the focusing connector being affected by excessive temperature and reducing unnecessary energy consumption.

[0096] The cooling control module is used to perform cooling start-up or cooling pause operations on the coking connector based on the cooling decision value.

[0097] In this embodiment of the invention, after receiving the cooling decision value transmitted by the cooling decision module, the cooling control module immediately responds and executes the corresponding operation: when the cooling decision value is the first preset value "1", the module activates the built-in micro-semiconductor cooling chip, which adheres tightly to the surface of the focusing connector through thermally conductive silicone, absorbing heat using the Peltier effect, and simultaneously turns on the matching micro-fan to accelerate heat dissipation, causing the surface temperature of the connector to gradually decrease from 35°C to below 30°C; when the cooling decision value is the second preset value "0", the module keeps the semiconductor cooling chip and fan in the off state, maintaining the temperature of the focusing connector only through natural heat dissipation, avoiding unnecessary cooling that could affect its deformation stability. During the cooling process, the module receives temperature feedback from the data acquisition module in real time. If the temperature drops to 28°C, it automatically switches to a pause state to ensure that the temperature of the focusing connector remains stable at the target length, satisfying the heat dissipation requirements while avoiding deformation regression caused by excessive cooling.

[0098] The present invention provides a camera multi-lens focusing system based on deformable metal, wherein the physical model module includes a heating effect unit, a cooling effect unit, a length change unit and a length update unit connected in sequence. The physical model module is a functional module in a multi-lens focusing system for cameras based on deformable metal, used to simulate and quantify the deformation process of the focusing connector under heating and cooling. By integrating the correlation between heating effects, cooling effects, and length changes, it constructs a dynamic deformation model of the focusing connector. This module sequentially includes a heating effect unit, a cooling effect unit, a length change unit, and a length update unit. By receiving input parameters such as heating current and cooling decision values, it calculates the heating effect value, cooling effect value, and length change, ultimately generating and updating the current length of the focusing connector. This provides real-time deformation status feedback to the core control module, ensuring accurate prediction and dynamic control of the focusing connector's deformation process. It is a key model supporting the connection between control signals and physical deformation.

[0099] A heating effect unit is used to generate heating effect values ​​based on heating current. Heating effect unit: A sub-unit in the physical model module used to quantify the effect of heating on the focusing connector. It calculates the heating effect value by heating current and effective heating time, reflecting the degree to which the heating process drives the deformation of the material.

[0100] Heating effect value: A quantitative parameter that measures the influence of the heating process on the deformation of the focusing connector. It is calculated based on current, time and material properties. The larger the value, the stronger the driving effect of heating on deformation.

[0101] Thermal effect coefficient: The correction coefficient between the thermal effect of the correlated current and the material deformation response. It is determined by the material properties (such as resistivity and specific heat capacity) and structural morphology of the focusing connector and needs to be calibrated experimentally.

[0102] Effective heating time: The heating duration when the pulse width modulation value obtained from the time recording module is greater than the preset threshold is a key time parameter for calculating the heating effect value.

[0103] In this embodiment of the invention, the heating effect unit pre-stores the thermal response parameters of the focusing connector. After receiving the heating current from the heating control module, it calculates the effect of the heat generated by the current on the material to generate a heating effect value. This value quantifies the degree to which the heating process drives the deformation of the focusing connector. The calculation is based on the correlation between Joule's law and the thermal effect of the material, and the formula is:

[0104] In the formula, This represents the heating effect value, in J. Indicates the thermal effect coefficient. This indicates the effective heating time recorded by the time recording module.

[0105] Cooling effect unit, used to generate cooling effect values ​​based on cooling decision values; Cooling effect unit: A sub-unit in the physical model module used to quantify the effect of cooling on the focusing connector. It calculates the cooling effect value by using the cooling decision value and the actual cooling time, reflecting the degree to which the cooling process inhibits or drives the material deformation.

[0106] Cooling effect value: A quantitative parameter that measures the impact of the cooling process on the deformation of the coking connector. It is calculated based on the cooling decision state, time and characteristics of the cooling device. The larger the value, the stronger the shrinkage driving effect of cooling on deformation.

[0107] Cooling effect coefficient: A correction coefficient that correlates cooling operation with material deformation response. It is determined by the cooling power, thermal conductivity, and thermal sensitivity of the focusing connector of the cooling device (such as a thermoelectric cooler). It needs to be calibrated experimentally.

[0108] Actual cooling duration: The duration during which the cooling control module executes the cooling start operation, calculated from the difference between the start and end times of cooling recorded by the data acquisition module. It is a key time parameter for calculating the cooling effect value.

[0109] In this embodiment of the invention, after receiving the cooling decision value transmitted by the cooling decision module, the cooling effect unit combines it with the actual cooling time of the cooling control module (calculated from the time information of the data acquisition module) to generate a cooling effect value that quantifies the cooling effect. This value reflects the degree of influence of the cooling process on the temperature drop and shrinkage deformation of the focusing connector. Its calculation is based on the correlation between the cooling decision state and the cooling time, as shown in the formula:

[0110] In the formula, This represents the cooling effect value, in J. This represents the cooling effect coefficient, taken as 0.6. Indicates the cooling decision value. This indicates the actual duration for the cooling control module to perform the cooling start-up operation.

[0111] The length variation unit is used to generate the length variation amount by taking the heating effect value and the cooling effect value as input to a preset length variation function; Length Variation Unit: A sub-unit in the physical model module used to calculate the deformation amplitude of the focusing connector. It integrates heating and cooling effect values ​​through a preset length variation function to generate the length variation amount and quantify the deformation result of the material under thermal action.

[0112] Preset length change function: A pre-defined mathematical relationship between the thermal effect difference and the length change. The energy difference is mapped to a specific length deformation amplitude through the length conversion coefficient, which is adapted to the thermo-mechanical properties of deformable metals.

[0113] Length change: The change in length of the focusing connector under the combined action of heating and cooling. Positive values ​​represent elongation and negative values ​​represent shrinkage. It directly reflects the actual range of material deformation and is the core parameter for updating the current length.

[0114] Length conversion factor: The proportionality coefficient between the difference in associated thermal effects and the amount of length change. It is determined by the material of the deformable metal (such as the phase transformation sensitivity of nickel-titanium alloy) and the cross-sectional size. Experimental calibration is used to ensure the accuracy of deformation calculation.

[0115] In this embodiment of the invention, after receiving the heating effect value from the heating effect unit and the cooling effect value from the cooling effect unit, the length variation unit inputs both into a preset length variation function. The difference between the two values ​​is calculated to quantify the net deformation effect of the focusing connector, generating a length variation value. This value directly reflects the elongation or contraction of the focusing connector under the combined effect of heat and cold. The expression for the preset length variation function is:

[0116] In the formula, Indicates the change in length. This represents the length conversion factor.

[0117] The length update unit is used to perform a summation operation between the length change and the current length, generate a new current length, and feed it back to the core control module.

[0118] Length Update Unit: A sub-unit in the physical model module used to correct the length parameters of the focusing connector in real time. It generates and outputs a new current length by performing a sum of the current length and the length change, thus maintaining the consistency between the physical model and the actual state.

[0119] New current length: The latest length of the focusing connector calculated by the length update unit reflects the actual deformation state of the material after heating and cooling, and is the latest length reference in closed-loop control.

[0120] Current length before update: The current length of the focusing connector before the length update is usually the real-time value detected by the core control module through the sensor, which serves as the basic parameter for length update.

[0121] Sum operation: A mathematical operation that adds the current length before the update to the length change. This operation enables dynamic correction of the length of the focusing connector, ensuring real-time parameter accuracy.

[0122] Data interface: The data transmission channel between the length update unit and the core control module, used to quickly feed back the new current length to the length deviation unit to ensure the continuity of closed-loop control.

[0123] In this embodiment of the invention, after receiving the length change from the length change unit, the length update unit calls the current length of the focusing connector synchronized in real time by the core control module, integrates the two through summation, and generates a new current length reflecting the latest state of the focusing connector, ensuring that the physical model is consistent with the actual deformation state. The calculation follows the formula:

[0124] In the formula, This indicates the new current length after the update. This indicates the current length before the update. This indicates the amount of length change generated by the length change unit.

[0125] The present invention provides a camera multi-lens focusing system based on deformable metal, and also includes a security monitoring module; The safety monitoring module is used to monitor the surface temperature and heating current of the connector in real time. When the surface temperature of the connector exceeds the preset surface temperature threshold or the heating current exceeds the preset heating current threshold, the heating subsystem is cut off, the cooling subsystem is started, and an alarm is output.

[0126] In this embodiment of the invention, the safety monitoring module maintains real-time data interaction with the data acquisition module and the heating control module. It continuously monitors the surface temperature of the connector through an independent temperature sampling channel (using an NTC thermistor shared with the cooling subsystem but with an independent AD conversion) (sampling frequency of 50Hz to ensure rapid response in case of abnormality). At the same time, it collects the heating current in real time through a current sensor (accuracy ±0.5mA) connected in parallel in the heating circuit. The sensor has a preset surface temperature threshold (set to 60℃ in this embodiment, which is the upper limit of the safe working temperature of deformable metal) and a preset heating current threshold (set to 120mA, which is 20mA higher than the maximum heating current to reserve a safety margin). When the surface temperature of the connector suddenly increases to 62℃ (greater than 60℃), or the heating current abnormally rises to 130mA (greater than 120mA), the module immediately triggers a three-level safety mechanism: First, it cuts off the MOSFET drive circuit of the heating subsystem via a hardware interrupt signal, forcibly stopping the heating current output; simultaneously, it sends a highest-priority cooling start command to the cooling subsystem (not controlled by the cooling decision module), causing the thermoelectric cooler and fan to operate at maximum power; finally, it outputs an alarm signal (including the abnormality type and value, such as "temperature over-limit: 62℃") to the system main controller via the I2C bus. After receiving the signal, the main controller records the alarm time and parameters in the device log and alerts the user by flashing indicator lights. If the abnormality is resolved (the temperature drops below 50℃ and the current returns to the normal range), the module automatically uninterrupts, allowing the heating subsystem to resume operation, but still keeps the cooling subsystem running for 3 seconds to consolidate the cooling effect.

[0127] This invention achieves optical focusing by using a deformable metal material (such as shape memory alloy, electrostrictive metal, etc.) in the connection structure between at least two lens groups in a multi-lens camera assembly; and by applying current or voltage to the deformable metal to utilize its thermal or electrostrictive deformation characteristics to directly change the spacing between the lens groups; and the deformation control signal is generated by an ISP (image processing module) or a dedicated drive circuit in response to focusing requirements.

[0128] It has the following advantages: Size optimization: By eliminating the VCM motor and magnet, the module thickness can be reduced by 20%~30%; Silent operation: With no moving mechanical parts, motor noise is completely eliminated; Energy saving: Deformable metal consumes energy only when energized, and has no energy consumption in a static state; Reliability: Reduces mechanical wear and extends service life.

[0129] Please see Figure 7 The present invention provides a focusing method for a multi-lens focusing system for a camera based on deformable metal, comprising: Step 101: When the image clarity of the current scene is detected to be lower than the preset defocus threshold, calculate the target length of the focusing connector.

[0130] Step 102: Based on the detected current length of the focusing connector, PID control is performed in conjunction with the target length to generate a pulse width modulation value.

[0131] Step 103: Convert the pulse width modulation value into a heating current and perform a heating operation on the focusing connector, and record the heating time when the pulse width modulation value is greater than the preset modulation threshold.

[0132] Step 104: Based on the current time of the focusing system and the surface temperature of the connector, make a cooling decision in combination with the current length, target length and heating time, and perform cooling start-stop operation on the focusing connector according to the cooling decision value.

[0133] Step 105: Calculate the length change of the coking connector based on the heating current and cooling decision value, generate a new current length based on the current length, and feed it back to the core control module.

[0134] Step 106: Generate mechanical deformation based on the new current length, change the axial distance between the two connected lens groups, and thus adjust the equivalent focal length of the adjustable lens group.

[0135] In this embodiment of the invention, when the image sharpness of the current scene captured by the camera is determined by the sharpness detection module to be lower than a preset defocus threshold, the system initiates an automatic focusing process. First, the defocus degree quantification module calculates the defocus degree value, then the defocus and displacement calibration mapping module determines the lens displacement, and finally, the length conversion module generates the target length of the focusing connector. The length deviation unit of the core control module calculates the difference between the current length and the target length, and the PID controller... The control unit generates an appropriate pulse width modulation (PWM) value based on the difference; the current mapping module of the heating subsystem converts the PWM value into a heating current, and the heating control module drives the current to flow through the focusing connector (such as a nickel-titanium alloy wire) to cause it to heat up and deform, while the time recording module records the effective heating time simultaneously; the data acquisition module of the cooling subsystem collects the current time and the surface temperature of the connector in real time, and the cooling decision module determines whether the cooling conditions are met by combining the current length, the target length, and the heating time, and the cooling control module executes cooling or pause operations according to the decision value; the heating effect unit and cooling effect unit of the physical model module calculate the corresponding effect values ​​respectively, the length change unit generates the length change amount through a preset function, and the length update unit integrates it with the current length to generate a new current length and feeds it back to the core control module; the focusing connector undergoes expansion and contraction deformation according to the new current length, causing the two connected lens groups to move along the optical axis to change the spacing, thereby adjusting the equivalent focal length of the adjustable lens group and restoring the image clarity to above the threshold.

[0136] It is worth mentioning that the focusing method, by employing deformable metal combined with PID closed-loop control, can achieve high-precision adjustment of the lens spacing (adjustment accuracy up to 0.001mm), significantly improving focusing accuracy. At the same time, the coordinated control of heating and cooling precisely regulates the deformation amplitude and stability of the deformable metal, which can shorten the focusing response time (≤100ms) and optimize the focusing performance in dynamic scenes. Furthermore, the integration of multi-parameter monitoring and safety mechanisms can prevent damage to the deformable metal due to overheating or overcurrent, improving the reliability of system operation. The entire process forms a complete closed loop, and the focal length can also be dynamically adjusted in real time according to the scene to adapt to different shooting distances and lighting conditions, enhancing the camera's environmental adaptability.

[0137] Please see Figure 8 System main loop flowchart and Figure 9 The schematic diagram of the Arduino control board circuit shows that, in actual operation, the multi-lens focusing system for cameras based on deformable metal (SMA alloy) first performs system initialization operations, completing the parameter configuration of each module and hardware status self-check. After entering the main loop, the system reads the target length of the focusing connector transmitted by the host computer through the serial port. The PID control unit of the core control module calculates the heating requirement and generates a pulse width modulation (PWM) value based on the deviation between the target length and the current length. Subsequently, pin 9 of the Arduino control board outputs a PWM signal to the gate of the MOSFET used for heating control, driving the heating circuit to conduct. The current passes through one end of the SMA alloy, the current sensing resistor (0.1Ω), etc., forming a loop to heat the SMA alloy. At the same time, the current sensing circuit feeds back the current signal to the control board through the analog input A0, realizing closed-loop monitoring of the heating current; the protection diode provides a reverse current path in case of circuit abnormality, ensuring the safety of the MOSFET.

[0138] During the heating process, the cooling control logic determines whether to activate cooling based on multiple conditions: if the SMA alloy needs to shrink, the surface temperature is too high, or heating has just ended, pin 10 of the Arduino control board will output a signal to the gate of the MOSFET used for cooling control, activating the cooling device. After completing the heating and cooling control, the system updates the SMA physical model, simulating the length change of the SMA alloy under heat-cooling action, and finally prints the system status, including parameters such as the current heating current, SMA alloy temperature, and length, realizing visualized monitoring and closed-loop adjustment of the focusing process.

[0139] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0140] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0141] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A camera multi-lens focusing system based on deformable metal, characterized in that, It includes a core control module, a heating subsystem, a cooling subsystem, a physical model module, and a camera; The camera includes an image sensor and an adjustable focus lens group; The adjustable focus lens group includes at least two groups of lenses arranged sequentially along the optical axis; A focusing connector is provided between the two sets of lenses, and the two ends of the focusing connector are respectively connected to the two sets of lenses; The image sensor is used to calculate the target length of the focusing connector when it detects that the image clarity of the current scene image is lower than a preset defocus threshold. The core control module is used to perform PID control based on the detected current length of the focusing connector and the target length to generate a pulse width modulation value. The heating subsystem is used to convert the pulse width modulation value into a heating current and perform a heating operation on the focusing connector, and to record the heating time when the pulse width modulation value is greater than a preset modulation threshold. The cooling subsystem is used to make a cooling decision based on the current time of the focusing system and the surface temperature of the connector, combined with the current length, the target length and the heating time, and to perform a cooling start-stop operation on the focusing connector according to the cooling decision value; The physical model module is used to calculate the length change of the focusing connector based on the heating current and the cooling decision value, generate a new current length by combining the current length, and feed it back to the core control module. The focusing connector is used to generate mechanical deformation according to the new current length, change the axial distance between the two connected lens groups, and thereby adjust the equivalent focal length of the adjustable lens group.

2. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The camera also includes a housing and a lens mount; The mirror mount is provided at the bottom of the housing; The image sensor is mounted on the front end of the mirror mount; The image sensor has brackets on both sides for fixing the adjustable focus lens group. The bracket is connected to a fixed-distance connector, which is used to fix the position of a portion of the lens; The adjustable lens group is located between the fixed distance connector and the focusing connector.

3. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The focusing connector is made of deformable metal material.

4. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The image sensor includes a defocusing degree quantization module, a defocusing and displacement calibration mapping module, and a length conversion module connected in sequence. The defocusing degree quantification module is used to determine the defocusing degree value by using the image clarity and the preset defocusing threshold when the image clarity of the current scene image is detected to be lower than the preset defocusing threshold. The defocus and displacement calibration mapping module is used to determine the lens displacement based on the preset defocus and displacement calibration mapping relationship and the defocus degree value. The length conversion module is used to perform a summation operation between the initial length of the focusing connector and the lens displacement to obtain the target length of the focusing connector within the adjustable lens group.

5. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The core control module includes an interconnected length deviation unit and a PID control unit; The length deviation unit is used to perform a difference calculation based on the detected current length of the focusing connector and the target length to obtain a length deviation value. The PID control unit is used to generate a pulse width modulation value by inputting a preset PID control function based on the length deviation value.

6. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The heating subsystem includes a current mapping module, a heating control module, and a time recording module connected in sequence. The current mapping module is used to input the pulse width modulation value into a preset current conversion function to generate a heating current; The heating control module is used to perform a heating operation on the focusing connector using the heating current; The time recording module is used to record the heating time when the pulse width modulation value is greater than a preset modulation threshold.

7. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The cooling subsystem includes a data acquisition module, a cooling decision module, and a cooling control module connected in sequence. The data acquisition module is used to acquire the current time of the focusing system and the surface temperature of the connector; The cooling decision module is used to determine whether the current focusing system meets the preset cooling start-up conditions based on the current time, the surface temperature of the connector, the current length, the target length, the heating time, and the preset length change value. If satisfied, the first preset value associated with the cooling start operation will be used as the cooling decision value. If the condition is not met, the second preset value associated with the cooling pause operation will be used as the cooling decision value. The cooling control module is used to perform a cooling start operation or a cooling pause operation on the focusing connector based on the cooling decision value.

8. The camera multi-lens focusing system based on deformable metal according to claim 1, characterized in that, The physical model module includes a heating effect unit, a cooling effect unit, a length change unit, and a length update unit connected in sequence. The heating effect unit is used to generate a heating effect value based on the heating current; The cooling effect unit is used to generate a cooling effect value based on the cooling decision value; The length change unit is used to input the heating effect value and the cooling effect value into a preset length change function to generate a length change amount; The length update unit is used to perform a summation operation between the length change and the current length to generate a new current length, and then feed it back to the core control module.

9. The camera multi-lens focusing system based on deformable metal according to any one of claims 1-8, characterized in that, It also includes a security monitoring module; The safety monitoring module is used to monitor the surface temperature of the connector and the heating current in real time. When the surface temperature of the connector is greater than a preset surface temperature threshold or the heating current is greater than a preset heating current threshold, the heating subsystem is cut off, the cooling subsystem is started, and an alarm is output.

10. A focusing method applied to the camera multi-lens focusing system based on deformable metal as described in any one of claims 1-9, characterized in that, include: When the image sharpness of the current scene is detected to be lower than the preset defocus threshold, the target length of the focusing connector is calculated. Based on the detected current length of the focusing connector, PID control is performed in conjunction with the target length to generate a pulse width modulation value; The pulse width modulation value is converted into a heating current and a heating operation is performed on the focusing connector. The heating time when the pulse width modulation value is greater than the preset modulation threshold is recorded. Based on the current time of the focusing system and the surface temperature of the connector, a cooling decision is made in combination with the current length, target length and heating time, and a cooling start-stop operation is performed on the focusing connector according to the cooling decision value; The length change of the coking connector is calculated based on the heating current and cooling decision value, and a new current length is generated by combining the current length and fed back to the core control module. The mechanical deformation generated by the new current length changes the axial distance between the two connected lens groups, thereby adjusting the equivalent focal length of the adjustable lens group.

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