A camera SFR test device with adjustable focal length function

Abstract

The present invention discloses a camera SFR test device with a function of adjustable focal length, specifically related to the technical field of camera SFR testing. It includes a body, an image analyzer for analyzing the images collected by the camera and performing SFR testing, a mounting base for mounting the camera, and a measurement pattern generator for providing a measurement pattern. A central processor is provided on one side of the image analyzer. Inside the body, a position adjustment structure and a clamping and stabilizing mechanism are respectively provided. The clamping and stabilizing mechanism is used to clamp and fix the camera lens to prevent the camera lens from vibrating. It also includes a lens position capture module, a vibration amplitude acquisition module, and a vibration frequency acquisition module. The present invention solves the problem of defocus caused by lens vibration during the focal length adjustment of a telescopic camera. By monitoring the vibration in real time and making intelligent adjustments, it ensures the image clarity and the accuracy of SFR testing.

Description

Technical Field

[0001] The present invention relates to the technical field of camera SFR testing, and more specifically, to a camera SFR testing device with a focal length adjustable function. Background Art

[0002] A camera SFR testing device with a focal length adjustable function is a dedicated device integrating focal length adjustment and image quality testing functions. Its main function is to test and evaluate the imaging quality of a camera at different focal lengths, especially through spatial frequency response (SFR) testing, to measure the clarity, sharpness, and image detail restoration ability of the camera under different focal length conditions. Specifically, the device can automatically or manually adjust the focal length of the camera and perform imaging tests at multiple focal length positions, thereby analyzing the impact of focal length changes on image quality. As a key image quality evaluation method, SFR testing can accurately evaluate the resolution and detail presentation ability of the camera at different focal lengths. This device is of great significance in camera research and development, production, quality control, and image performance evaluation. It not only helps to detect and verify the imaging effect of the camera but also optimizes the focal length adjustment mechanism to improve the overall image quality of the camera, and is widely used in fields such as security monitoring, autonomous driving, and industrial inspection.

[0003] Existing camera SFR testing devices with a focal length adjustable function evaluate the image quality of a camera at different focal lengths through a series of precise steps. First, the device automatically or manually adjusts the focal length of the camera, usually through an electric motor or a mechanical control system, to ensure that the focal length changes within a predetermined range. Next, the device aligns the camera with a standard test pattern, usually a high-contrast resolution test chart or a sine wave pattern, which can simulate image details of different spatial frequencies. Then, the device gradually takes pictures of the test pattern at different focal lengths and measures the spatial frequency response (SFR) of the image through image analysis software, that is, tests the clarity, sharpness, and resolution of the camera at each focal length. Finally, the system generates a series of SFR data, analyzes the impact of focal length changes on the imaging quality of the camera, and evaluates its performance at different focal lengths. This process ensures that the image quality of the camera under various focal length conditions meets the expected standards and helps developers or manufacturers optimize the focal length adjustment system and image quality.

[0004] The prior art has the following deficiencies: When adjusting the focal length, especially when the focal length changes significantly (for example, from telephoto to wide-angle), the internal optical components of the lens of the telescopic camera need to undergo a large displacement. Since the lens of the telescopic camera moves outward or inward during the focal length adjustment process, if the lens after the focal length adjustment lacks sufficient support and stability, it may vibrate slightly, resulting in defocusing at the moment of image capture. This situation is particularly obvious when the focal length adjustment amplitude is large. The existing SFR test device for cameras with adjustable focal length cannot effectively stabilize the position of the lens of the telescopic camera after focal length adjustment. Therefore, it is impossible to avoid the vibration of the lens after focal length adjustment, resulting in defocusing of the image during shooting, and further making the test image blurred. This will directly affect the accuracy of the SFR test, resulting in a low SFR calculation result, and thus making the test data unreliable.

[0005] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides an SFR test device for cameras with adjustable focal length to solve the problems proposed in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An SFR test device for cameras with adjustable focal length includes a body, an image analyzer for analyzing the images collected by the camera and performing SFR tests, a mounting base for mounting the camera, and a measurement pattern generator for providing a measurement pattern. A central processor is provided on one side of the image analyzer. A position adjustment structure and a clamping and stabilizing mechanism are respectively provided inside the body. The clamping and stabilizing mechanism is used to clamp and fix the camera lens to prevent the camera lens from vibrating. The position adjustment mechanism is used to control the clamping and stabilizing mechanism to accurately move to the position of clamping and fixing the camera lens;

[0009] It further includes:

[0010] A lens position capture module, which is provided on the inner bottom wall of the body, is used to obtain the position information of the camera lens in real time and transmit it to the central processor for analysis to determine the position of the camera lens;

[0011] A vibration amplitude acquisition module, which is provided on the inner bottom wall of the body, is used to obtain the vibration amplitudes of the camera lens at different moments within a period of time in real time and generate a vibration amplitude change coefficient through the central processor;

[0012] The vibration frequency acquisition module is arranged on the inner side wall of the mounting base and is used to obtain the vibration frequencies of the camera at different moments within a period of time in real time, and generate a vibration frequency deviation index through the central processor;

[0013] The central processor comprehensively analyzes the generated vibration amplitude change coefficient and vibration frequency deviation index to generate a vibration judgment coefficient. By comparing the vibration judgment coefficient with a preset vibration judgment coefficient reference threshold, it is judged whether the vibration of the camera lens will affect the SFR test according to the comparison result, and the working states of the position adjustment structure, the clamping stability mechanism and the lens position capture module are controlled according to the comparison result.

[0014] Preferably, the position adjustment mechanism includes a motor mounting frame, a motor, a gear transmission box, a lead screw and a sliding frame. One side of the motor mounting frame is fixedly connected to the inner side wall of the machine body, the top of the motor mounting frame is fixedly connected to the bottom of the motor, the output shaft of the motor is in transmission connection with the input shaft of the gear transmission box, the output shaft of the gear transmission box is in transmission connection with one end of the lead screw, and the outer wall of the lead screw is in transmission connection with the inner side wall of the sliding frame.

[0015] Preferably, the clamping stability mechanism includes a cylinder mounting frame, a cylinder, a telescopic rod, an arc-shaped clamping plate and an arc-shaped sponge plate. One side of the cylinder mounting frame is fixedly connected to one side of the sliding frame, the top of the cylinder mounting frame is fixedly connected to the bottom of the cylinder, the output end of the cylinder is in transmission connection with one end of the telescopic rod, the other end of the telescopic rod is fixedly connected to one side of the arc-shaped clamping plate, and the inner side wall of the arc-shaped clamping plate is fixedly connected to the outer wall of the arc-shaped sponge plate.

[0016] Preferably, the output end of the central processor is electrically connected to the input end of the motor, the input end of the cylinder, the input end of the image analyzer and the input end of the measurement pattern generator respectively. The output end and input end of the lens position capture module, the output end and input end of the vibration amplitude acquisition module, and the output end and input end of the vibration frequency acquisition module are electrically connected to the input end and output end of the central processor respectively.

[0017] Preferably, the acquisition logic of the vibration amplitude change coefficient is as follows:

[0018] S1. The vibration amplitudes of the camera lens at different moments within a period of time are obtained in real time through the vibration amplitude acquisition module and are calibrated as , indicating the vibration amplitude of the camera lens at the th moment within a period of time, , being a positive integer;

[0019] S2. The preset maximum vibration amplitude allowed for the camera lens is obtained through the central processor and is calibrated as ;

[0020] S3. Establish a set of the vibration amplitudes of the camera lens at different moments within a period of time and recalibrate the vibration amplitudes greater than the preset maximum vibration amplitude in the set as , where represents the number of the vibration amplitude greater than the preset maximum vibration amplitude in the set, , and

[0021] S4. Calculate the vibration amplitude change coefficient, and the calculation expression is:

[0022]

[0023] In the formula, is the vibration amplitude change coefficient.

[0024] Preferably, the acquisition logic of the vibration frequency deviation index is as follows:

[0025] S1. Real-time acquire the vibration frequencies of the camera at different moments within a period of time through the vibration frequency acquisition module and calibrate them as , where represents the vibration frequency of the camera at the th moment within a period of time,

[0026] S2. Acquire the preset maximum vibration frequency allowed for the camera through the central processing unit and calibrate it as ;

[0027] S3. Calculate the vibration frequency deviation index, and the calculation expression is:

[0028]

[0029] In the formula, is the vibration frequency deviation index.

[0030] Preferably, the expression formula of the vibration judgment coefficient is:

[0031] Perform formula-based analysis through the central processing unit according to the formula:

[0032]

[0033] In the formula, is the vibration judgment coefficient, and are respectively the vibration amplitude change coefficients and the vibration frequency deviation index of a preset proportionality coefficient, and and are both greater than 0.

[0034] Preferably, the preset reference threshold of the vibration judgment coefficient is set to , and the calculated vibration judgment coefficient and the preset reference threshold of the vibration judgment coefficient are compared by the central processing unit. According to the comparison result, it is judged whether the vibration of the camera lens will affect the SFR test, and the working states of the position adjustment structure, the clamping stability mechanism and the lens position capture module are controlled according to the comparison result. The specific judgment is as follows:

[0035] When , the vibration of the camera lens will not affect the SFR test, and a normal signal is generated. After receiving the normal signal, the central processing unit generates a standby signal and transmits it to the motor, the cylinder and the lens position capture module respectively. After receiving the standby signal, the motor and the cylinder control the position adjustment structure and the clamping stability mechanism to perform standby operations respectively. After receiving the standby signal, the lens position capture module also performs standby operations;

[0036] When , the vibration of the camera lens will affect the SFR test, and an abnormal signal is generated. After receiving the abnormal signal, the central processing unit generates a capture signal, a movement signal and a clamping signal, transmits the capture signal to the lens position capture module. After receiving the capture signal, the lens position capture module performs lens position capture work, transmits the movement signal to the motor. After receiving the movement signal, the motor controls the position adjustment structure to perform position adjustment work, and transmits the clamping signal to the cylinder. After receiving the clamping signal, the cylinder controls the clamping stability mechanism to perform clamping stability work.

[0037] The technical effects and advantages of the present invention:

[0038] 1. The present invention effectively solves the vibration problem that occurs when the telescopic camera lens adjusts the focal length significantly during the focal length adjustment process. Through the vibration amplitude acquisition module and the vibration frequency acquisition module, the vibration of the camera lens is monitored in real time. The central processing unit can judge whether the vibration of the lens will affect the SFR test result according to the calculated vibration amplitude change coefficient and the vibration frequency deviation index. If the vibration exceeds the preset tolerance threshold, the system will automatically start the position adjustment mechanism and the clamping stability mechanism to ensure the stability of the lens and avoid defocusing. Through this precise vibration monitoring and adjustment mechanism, this technical solution effectively ensures the stability of the camera under different focal length conditions, ensures the clarity of the image, and avoids defocusing caused by vibration.

[0039] 2. The greatest advantage of the present invention lies in its ability of real-time feedback and dynamic adjustment. Through the comprehensive analysis of the vibration amplitude and frequency, the central processing unit can grasp the vibration situation of the lens in real time and judge the impact of the vibration on the test results. When the vibration reaches a certain threshold, the system can timely adjust the position adjustment structure and the clamping and stabilizing mechanism to ensure the stability of the lens and avoid the impact of vibration on the focal length adjustment. In addition, the real-time monitoring function of the lens position capture module enables the system to quickly respond and accurately adjust the position of the lens, further improving the accuracy of the focal length adjustment and the image quality.

[0040] 3. The present invention can significantly improve the accuracy of the SFR test. The impact of vibration on the SFR test results is usually difficult to avoid, especially when the focal length adjustment amplitude is large. This solution effectively avoids the out-of-focus problem caused by lens vibration through precise vibration monitoring and lens stability control, thus ensuring the image quality and the accuracy of the SFR calculation. The real-time analysis and intelligent control of the vibration data by the central processing unit not only improve the stability of the device, but also enhance the reliability of the test data, making the entire SFR test process more accurate and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings;

[0042] Figure 1 FIG. is a three-dimensional structure schematic diagram of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0043] Figure 2 FIG. is a front structure schematic diagram of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0044] Figure 3 FIG. is a top structure schematic diagram of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0045] Figure 4 FIG. is a schematic diagram of the installation structure of the determination pattern generator of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0046] Figure 5 FIG. is a schematic diagram of the structure of the position adjustment mechanism of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0047] Figure 6 FIG. is a schematic diagram of the structure of the clamping and stabilizing mechanism of a camera SFR test device with a focal length adjustable function proposed by the present invention;

[0048] Figure 7Schematic diagram of the installation structure of the vibration frequency acquisition module of a camera SFR test device with adjustable focal length function proposed by the present invention;

[0049] Figure 8 Module diagram of a camera SFR test device with adjustable focal length function proposed by the present invention.

[0050] In the figure: 1, body; 2, image analyzer; 3, mounting base; 4, measurement pattern generator; 5, central processor; 6, position adjustment mechanism; 601, motor mounting frame; 602, motor; 603, gear transmission box; 604, lead screw; 605, sliding frame; 7, clamping and stabilizing mechanism; 701, cylinder mounting frame; 702, cylinder; 703, telescopic rod; 704, arc-shaped clamping plate; 705, arc-shaped sponge plate; 8, lens position capture module; 9, vibration amplitude acquisition module; 10, vibration frequency acquisition module. Specific implementation mode

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0052] Embodiment

[0053] As Figure 1-8 shown, a camera SFR test device with adjustable focal length function includes a body 1, an image analyzer 2 for analyzing the images collected by the camera and performing SFR tests, a mounting base 3 for mounting the camera, and a measurement pattern generator 4 for providing a measurement pattern. A central processor 5 is provided on one side of the image analyzer 2. A position adjustment structure 6 and a clamping and stabilizing mechanism 7 are respectively provided inside the body 1. The clamping and stabilizing mechanism 7 is used to clamp and fix the camera lens to prevent the camera lens from vibrating. The position adjustment mechanism 6 is used to control the accurate movement of the clamping and stabilizing mechanism 7 to the position of clamping and fixing the camera lens;

[0054] It further includes:

[0055] A lens position capture module 8, which is arranged on the inner bottom wall of the body 1, is used to obtain the position information of the camera lens in real time and transmit it to the central processor 5 for analysis to determine the position of the camera lens;

[0056] It should be noted that the lens position capture module 8 can be an optical position sensor or other devices that can obtain the position information of the camera lens in real time. The lens position capture module 8 is not specifically limited here and can be selected according to actual needs.

[0057] The vibration amplitude acquisition module 9 is arranged on the inner bottom wall of the body 1 and is used to obtain the vibration amplitudes of the camera lens at different moments within a period of time in real time, and generate a vibration amplitude change coefficient through the central processor 5;

[0058] It should be noted that the vibration amplitude acquisition module 9 can be an acceleration sensor, a displacement sensor or other devices that can obtain the vibration amplitudes of the camera lens at different moments within a period of time in real time. The vibration amplitude acquisition module 9 is not specifically limited here and can be selected according to actual needs.

[0059] The vibration frequency acquisition module 10 is arranged on the inner side wall of the mounting base 3 and is used to obtain the vibration frequencies of the camera at different moments within a period of time in real time, and generate a vibration frequency deviation index through the central processor 5;

[0060] It should be noted that the vibration frequency acquisition module 10 can be a vibration sensor or other devices that can obtain the vibration frequencies of the camera at different moments within a period of time in real time. The vibration frequency acquisition module 10 is not specifically limited here and can be selected according to actual needs.

[0061] The central processor 5 comprehensively analyzes the generated vibration amplitude change coefficient and vibration frequency deviation index to generate a vibration judgment coefficient. By comparing the vibration judgment coefficient with a pre-set reference threshold of the vibration judgment coefficient, it is judged whether the vibration of the camera lens will affect the SFR test according to the comparison result, and the working states of the position adjustment structure 6, the clamping and stabilizing mechanism 7 and the lens position capture module 8 are controlled according to the comparison result.

[0062] It should be noted that the pre-set reference threshold of the vibration judgment coefficient can be determined in various ways. Usually, it is set based on experimental data, camera performance standards and actual application requirements. Specifically, it can be determined by the following methods: First, through multiple on-site tests, collect the performance data of the camera under different vibration conditions, and analyze the influence of vibration on the SFR test results, so as to determine a reasonable vibration threshold; Second, according to the physical characteristics of the lens such as weight, material, structure, etc. and performance requirements, set a preliminary vibration tolerance range; Finally, refer to industry standards or test data of similar devices, and combine the allowable vibration range in actual applications for adjustment and optimization. The central processor 5 will use this set reference threshold to compare it with the vibration judgment coefficient calculated in real time. When the vibration exceeds the threshold, the system automatically takes measures to reduce the influence of vibration on the image quality and ensure the accuracy of the SFR test.

[0063] Further, it should be noted that the image analyzer 2 is responsible for real-time analysis of the images captured by the camera and performing SFR (Spatial Frequency Response) tests. First, the image analyzer 2 receives the image data captured by the camera and analyzes the spatial frequency and sharpness in the image through image processing algorithms such as Fourier transform, edge detection, contrast analysis, etc. The image analyzer 2 calculates the SFR value of the image, which reflects the resolution ability of the image at different spatial frequencies. By comparing the differences between the test pattern and the image captured by the camera, the image analyzer 2 can accurately evaluate the resolution performance of the camera. The image analyzer 2 is usually equipped with a powerful central processing unit (CPU) and an image processing chip, which can quickly process a large amount of image information and generate a detailed report on the image quality for judging whether the imaging quality of the camera meets the standard requirements.

[0064] The measurement pattern generator 4 is responsible for providing standardized test patterns for the camera to perform SFR tests. This generator usually consists of a high-resolution display, a projection device, or a precision printer, and can generate standard patterns with specific spatial frequencies, contrasts, and geometric shapes. These patterns include grids, sine waves, lines, grayscale gradients, etc., which are used to test the imaging ability of the camera at different focal lengths and shooting distances. The measurement pattern generator 4 simulates different scenes in the actual shooting environment by adjusting the details and complexity of the pattern, thereby helping to evaluate the resolution performance of the camera under various conditions. The generated patterns can be displayed at a fixed resolution and contrast to ensure consistency and reliability during the image acquisition process and provide accurate comparison data for the image analyzer 2.

[0065] In this embodiment, the position adjustment mechanism 6 includes a motor mounting bracket 601, a motor 602, a gear transmission box 603, a lead screw 604, and a sliding bracket 605. One side of the motor mounting bracket 601 is fixedly connected to the inner side wall of the body 1, the top of the motor mounting bracket 601 is fixedly connected to the bottom of the motor 602, the output shaft of the motor 602 is in transmission connection with the input shaft of the gear transmission box 603, the output shaft of the gear transmission box 603 is in transmission connection with one end of the lead screw 604, and the outer wall of the lead screw 604 is in transmission connection with the inner side wall of the sliding bracket 605.

[0066] It should be noted that the gear transmission box 603 mainly transmits the rotational kinetic energy transmitted by the motor 602 to the lead screw 604 through the cooperation of the internal gears, and then controls the lead screw 604 to rotate. The cooperation method of the internal gears of the gear transmission box 603 is not specifically limited here and can be selected according to actual needs.

[0067] In this embodiment, the clamping and stabilizing mechanism 7 includes a cylinder mounting bracket 701, a cylinder 702, a telescopic rod 703, an arc-shaped clamping plate 704, and an arc-shaped sponge plate 705. One side of the cylinder mounting bracket 701 is fixedly connected to one side of the sliding bracket 605, the top of the cylinder mounting bracket 701 is fixedly connected to the bottom of the cylinder 702, the output end of the cylinder 702 is drivingly connected to one end of the telescopic rod 703, the other end of the telescopic rod 703 is fixedly connected to one side of the arc-shaped clamping plate 704, and the inner side wall of the arc-shaped clamping plate 704 is fixedly connected to the outer wall of the arc-shaped sponge plate 705.

[0068] The clamping and stabilizing mechanism 7 is used to clamp and fix the camera lens to prevent the camera lens from vibrating. The position adjustment mechanism 6 is used to control the accurate movement of the clamping and stabilizing mechanism 7 to the position where the camera lens is clamped and fixed. The specific implementation method is as follows: The position adjustment mechanism 6 supports the motor 602 through the motor mounting bracket 601 and transmits the rotational power of the motor 602 to the gear transmission box 603, thereby driving the rotation of the lead screw 604. The rotation of the lead screw 604 drives the sliding bracket 605 to translate along its track, ensuring that the cylinder mounting bracket 701 of the clamping and stabilizing mechanism 7 can accurately move inside the body 1 to the clamping position of the camera lens. When the sliding bracket 605 moves, it drives the cylinder mounting bracket 701 to be fixed at the corresponding position, and the cylinder 702 provided on the cylinder mounting bracket 701 drives the telescopic movement of the telescopic rod 703 through its output end, controlling the position of the arc-shaped clamping plate 704. The arc-shaped clamping plate 704 is fixedly connected to the arc-shaped sponge plate 705. Under the action of the telescopic rod 703, the arc-shaped clamping plate 704 will surround and clamp the camera lens to ensure the stability of the lens and prevent vibration. At this time, the clamping and stabilizing mechanism 7 stabilizes the position of the camera lens through the buffering action of its arc-shaped clamping plate 704 and arc-shaped sponge plate 705. Through this cooperation, the position adjustment mechanism 6 ensures that the clamping and stabilizing mechanism 7 can accurately move to the lens position and clamp and fix it, thereby preventing the camera lens from being out of focus due to vibration during the focal length adjustment process.

[0069] In this embodiment, the output end of the central processing unit 5 is electrically connected to the input end of the motor 602, the input end of the cylinder 702, the input end of the image analyzer 2, and the input end of the measurement pattern generator 4 respectively. The output end and input end of the lens position capture module 8, the output end and input end of the vibration amplitude acquisition module 9, and the output end and input end of the vibration frequency acquisition module 10 are electrically connected to the input end and output end of the central processing unit 5 respectively;

[0070] It should be noted that electrical connection refers to the process of transmitting current from one part of an electronic device or circuit to another through a conductive material or conductive component. This connection is a crucial part of the operation of electronic devices and circuits, ensuring the effective transmission and connection of the electron flow in electronic devices. Electrical connection can be achieved using wires. The specific way of electrical connection between the central processor 5 and the motor 602, the cylinder 702, the image analyzer 2, the measurement pattern generator 4, the lens position capture module 8, the vibration amplitude acquisition module 9, and the vibration frequency acquisition module 10 is not specifically limited and can be selected according to actual needs.

[0071] During the focal length adjustment, especially when the focal length changes significantly, such as from telephoto to wide-angle, the internal optical components of the lens of a telescopic camera need to undergo a large displacement. Since the lens of a telescopic camera moves outward or inward during the focal length adjustment, if the lens after focal length adjustment lacks sufficient support and stability, it may vibrate slightly, resulting in defocus at the moment of image capture. This situation is particularly obvious when the focal length adjustment amplitude is large. The existing SFR test device for cameras with adjustable focal length function cannot effectively stabilize the position of the lens of the telescopic camera after focal length adjustment. Therefore, it is impossible to avoid the vibration of the lens after focal length adjustment, resulting in defocus of the image during shooting, and further making the test image blurred. This will directly affect the accuracy of the SFR test, leading to a low SFR calculation result, and thus making the test data unreliable.

[0072] Therefore, solving this technical problem is of great significance. The lens vibration and defocus phenomenon during the focal length adjustment will directly affect the clarity of the image, and further lead to inaccurate SFR test data. Especially when the focal length changes significantly, the optical components of the telescopic camera will undergo a large displacement. At this time, the lens lacks sufficient support and stability, and is prone to vibration or rebound, resulting in a blurred image. By setting the clamping and stabilizing mechanism 7 and the position adjustment mechanism 6, it is possible to provide precise lens support and stability after focal length adjustment, avoiding the impact of vibration on the image quality and test results. This solution not only improves the lens stability during the focal length adjustment, but also ensures the accuracy of the SFR test, avoids the error caused by defocus, makes the image data more reliable, and thus improves the overall performance and application value of the test equipment.

[0073] In this embodiment, the vibration amplitude change coefficient is a parameter obtained by analyzing and calculating the vibration amplitude of the camera lens at different time periods. Specifically, the AVC collects the vibration amplitudes of the camera at different moments during the focal length adjustment process, and combines the processing of the vibration data by the central processing unit 5 to calculate the change of the vibration amplitude. The magnitude of the AVC reflects the degree of change in the vibration amplitude of the camera lens. The larger the value, the more significant the change in the vibration amplitude and the worse the lens stability. In the SFR test, the higher the AVC value, the greater the impact of vibration on the lens, and thus the more likely it is to cause image defocus and inaccurate test results. Therefore, the magnitude of the AVC is closely related to determining whether the vibration of the camera lens will affect the SFR test.

[0074] The acquisition logic of the vibration amplitude change coefficient is as follows:

[0075] S1. The vibration amplitude acquisition module 9 is used to obtain the vibration amplitudes of the camera lens at different moments within a period of time in real time, and calibrate them as , indicating the vibration amplitude of the camera lens at the th moment within a period of time, , where

[0076] To achieve real-time acquisition of the vibration amplitudes of the camera lens at different moments within a period of time, various sensors or devices can be used to capture vibration signals. Common implementation methods include: acceleration sensors, which reflect the vibration amplitude by measuring the acceleration changes of the camera lens in different directions; displacement sensors, which obtain the vibration amplitude information by accurately measuring the minute displacement changes of the lens; piezoelectric sensors, which utilize the piezoelectric effect to detect the force changes caused by vibration and convert them into electrical signals; and optical sensors, which capture the vibration amplitude by measuring the changes on the lens surface or other reference points. These sensors collect vibration data in real time, convert it into digital signals through analog-to-digital conversion technology, and then transmit the data to the central processing unit through communication interfaces such as I2C or SPI for further analysis and processing, so as to obtain and monitor the changes in the lens vibration amplitude in real time.

[0077] S2. The central processing unit 5 is used to obtain the preset maximum vibration amplitude allowed for the camera lens, and calibrate it as ;

[0078] The preset maximum vibration amplitude of the camera lens allowed is obtained by the central processor 5, which is usually achieved by a pre-set maximum vibration amplitude threshold. These preset maximum vibration amplitudes can be determined based on experimental data, physical characteristics of the camera or industry standards. The acquisition method includes: setting a threshold when the system is initialized, defining the threshold through user input or standardized test settings; or dynamically adjusting the maximum vibration amplitude according to historical test data and lens performance requirements. The central processor 5 will read these preset vibration amplitude thresholds and compare them with the vibration amplitude collected in real time to determine whether the current vibration amplitude exceeds the allowable range. If the real-time data exceeds the preset threshold, the central processor will initiate corresponding control measures to ensure the stability of the lens and avoid vibration affecting the SFR test results. The specific method for obtaining the preset maximum vibration amplitude is not specifically limited here and can be selected according to actual needs.

[0079] S3. The vibration amplitude of the camera lens at different times within a period of time Create a collection and add the vibration amplitudes in the collection that are greater than the preset maximum The vibration amplitude is recalibrated as , Indicates that the vibration amplitude in the set is greater than the preset maximum The vibration amplitude number, , is a positive integer;

[0080] S4. Calculate the vibration amplitude variation coefficient. The calculation expression is:

[0081]

[0082] In the formula, is the coefficient of variation of vibration amplitude.

[0083] In this embodiment, the vibration frequency deviation index is a parameter obtained by analyzing and calculating the deviation of the camera lens vibration frequency, which reflects the frequency change of the lens vibration. Specifically, FDC is obtained by collecting the vibration frequency of the camera at different time points and calculating the deviation between it and the preset maximum vibration frequency ZPMAX. The size of FDC is directly related to the frequency deviation of the lens vibration. The larger the value, the greater the frequency deviation of the lens vibration. The higher the vibration frequency deviation index, the more drastic the vibration frequency change of the camera lens, which may lead to unstable focal length adjustment, affect the focusing effect of the lens, and further affect the accuracy of the SFR test.

[0084] The logic for obtaining the vibration frequency deviation index is:

[0085] S1. The vibration frequency of the camera at different times within a period of time is obtained in real time through the vibration frequency acquisition module 10, and calibrated as , represents the vibration frequency of the camera at a certain moment within a period of time , where , is a positive integer;

[0086] To achieve real-time acquisition of the vibration frequency of the camera at different moments within a period of time, it can be accomplished through a variety of sensors or devices. Common methods include using accelerometers, gyroscopes, or vibration sensors. Accelerometers can measure the acceleration changes of the camera in different directions, and the vibration frequency can be calculated through these acceleration signals. Gyroscopes can detect the rotation angle changes of the lens, further reflecting the vibration frequency characteristics. Vibration sensors, especially piezoelectric sensors, can capture the vibration frequency by sensing the tiny force changes caused by vibration. The above sensors will convert the captured vibration signals into electrical signals and transmit them to the central processor in real time through a data acquisition system for analysis and processing. These real-time data can help the system accurately monitor the vibration frequency of the lens, and then judge the impact of vibration on focus adjustment and image quality.

[0087] S2. Obtain the preset maximum vibration frequency allowed for the camera through the central processor 5, and calibrate it as ;

[0088] Obtaining the preset maximum vibration frequency allowed for the camera through the central processor 5 is usually achieved through a preset maximum vibration frequency threshold. This threshold can be set according to the design specifications, performance standards, and actual application requirements of the camera. The obtaining methods include: at the system initialization, setting the maximum vibration frequency through user input or standardized test data; or dynamically adjusting the threshold based on historical test data and the physical characteristics of the camera lens. The central processor 5 will read these preset maximum vibration frequency values and use them as a reference to compare with the real-time acquired vibration frequency data. If the real-time frequency exceeds this preset threshold, the system can judge that the vibration has exceeded the tolerance range, thereby triggering an automatic adjustment mechanism to avoid the impact of vibration on focus adjustment and image quality. The specific obtaining method of the preset maximum vibration frequency is not specifically limited here and can be selected according to actual needs.

[0089] S3. Calculate the vibration frequency deviation index, and the calculation expression is:

[0090]

[0091] In the formula, is the vibration frequency deviation index.

[0092] In this embodiment, the expression formula of the vibration judgment coefficient is:

[0093] Let and After dimensionless processing, formulaic analysis is performed by the central processing unit 5 according to the formula:

[0094]

[0095] In the formula, is the vibration judgment coefficient, and are respectively the vibration amplitude change coefficient and the vibration frequency deviation index preset proportionality coefficients, and and are both greater than 0;

[0096] It can be seen from the calculated expression that the larger the vibration amplitude change coefficient and the vibration frequency deviation index are, the larger the vibration judgment coefficient will be;

[0097] It should be noted that dimensionless processing is a process of expressing physical quantities in a dimensionless form. By this way, the influence of units on physical problems can be eliminated, making the problem more concise and general; the preset proportionality coefficients of the vibration amplitude change coefficient and the vibration frequency deviation index and are for more flexibly adapting to different working conditions and environmental changes in actual monitoring. These deviation coefficients can be adjusted according to specific situations to improve the performance and applicability of the monitoring system.

[0098] In this embodiment, the preset reference threshold of the vibration judgment coefficient is set to , and the calculated vibration judgment coefficient is compared with the preset reference threshold of the vibration judgment coefficient by the central processing unit 5. According to the comparison result, it is judged whether the vibration of the camera lens will affect the SFR test, and the working states of the position adjustment structure 6, the clamping and stabilizing mechanism 7, and the lens position capturing module 8 are controlled according to the comparison result. The specific judgment is as follows:

[0099] When , the vibration of the camera lens will not affect the SFR test, and a normal signal is generated. After receiving the normal signal, the central processing unit 5 generates a standby signal and transmits it to the motor 602, the cylinder 702, and the lens position capturing module 8 respectively. After receiving the standby signal, the motor 602 and the cylinder 702 control the position adjustment structure 6 and the clamping and stabilizing mechanism 7 to perform standby operations respectively. After receiving the standby signal, the lens position capturing module 8 also performs standby operations;

[0100] Standby operation means that when there is no abnormal situation or adjustment required, the device or system enters a low-power, non-operating state to maintain system stability and save energy. In this solution, when the vibration of the camera lens does not affect the SFR test, the central processor 5 generates a standby signal. After receiving the standby signal, the motor 602 and the cylinder 702 will control the position adjustment structure 6 and the clamping and stabilizing mechanism 7 to enter the standby operation state, which means these components stop making any adjustments or movements and maintain the current stable state; after receiving the standby signal, the lens position capture module 8 also enters the standby operation state and stops monitoring the lens position in real time. The standby operation state ensures that the system is in an energy-saving and non-operating state, avoiding unnecessary operations or energy consumption, and activating the corresponding modules again until an operation or adjustment is required.

[0101] When the vibration of the camera lens affects the SFR test and generates an abnormal signal, after receiving the abnormal signal, the central processor 5 generates a capture signal, a movement signal, and a clamping signal, transmits the capture signal to the lens position capture module 8. After receiving the capture signal, the lens position capture module 8 performs the lens position capture operation, transmits the movement signal to the motor 602. After receiving the movement signal, the motor 602 controls the position adjustment structure 6 to perform the position adjustment operation, and transmits the clamping signal to the cylinder 702. After receiving the clamping signal, the cylinder 702 controls the clamping and stabilizing mechanism 7 to perform the clamping and stabilizing operation.

[0102] The lens position capture operation means that after receiving the capture signal, the lens position capture module 8 obtains the position information of the camera lens in real time and transmits it to the central processor 5 for analysis to determine the position of the camera lens. The lens position capture module 8 obtains the precise position data of the lens by monitoring the position change of the camera lens in real time. This is usually accomplished by using position sensors such as accelerometers, optical encoders, or capacitive displacement sensors, which detect the minute movement of the lens and generate signals that are transmitted to the central processor 5. This operation ensures that when the camera lens vibrates or its position changes, the system can accurately know the position of the lens, providing real-time data for subsequent adjustment and stabilization operations. The reason for performing the lens position capture operation is to ensure that the lens position can be adjusted in a timely manner under vibration conditions, preventing defocus caused by lens displacement, thereby ensuring the accuracy of the SFR test results.

[0103] The position adjustment operation means that after receiving the movement signal, the motor 602 transmits the output rotational power to the gear transmission box 603, thereby driving the rotation of the lead screw 604. The rotation of the lead screw 604 drives the carriage 605 to translate along its track, ensuring that the cylinder mounting bracket 701 of the clamping and stabilizing mechanism 7 can accurately move inside the body 1 to the clamping position of the camera lens.

[0104] The stable clamping operation means that after the cylinder 702 receives the clamping signal, it drives the telescopic rod 703 to expand and contract through its output end, controls the position of the arc-shaped clamping plate 704. Under the action of the telescopic rod 703, the arc-shaped clamping plate 704 will surround and clamp the camera lens to ensure the stability of the lens and prevent vibration. At this time, the clamping stability mechanism 7 stabilizes the position of the camera lens through the buffering effect of its arc-shaped clamping plate 704 and arc-shaped sponge plate 705.

[0105] The above formulas are all dimensionless and take their numerical values for calculation. The formula is obtained by collecting a large amount of data and performing software simulation to obtain a formula that is closest to the actual situation. The preset parameters in the formula are set by those skilled in the art according to the actual situation.

[0106] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0107] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0108] In several embodiments provided by the present application, it should be understood that the disclosed overall system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another overall system, or some features can be ignored or not executed. Another point, the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical, or other forms.

[0109] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0110] In addition, each functional unit in various embodiments of the present application may be integrated into one processing unit, may exist physically alone for each unit, or two or more units may be integrated into one unit.

[0111] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A camera SFR test device with a focus adjustable function, comprising a body (1), an image analyzer (2) for analyzing an image captured by a camera and performing an SFR test, a mounting base (3) for mounting the camera, and a measurement pattern generator (4) for providing a measurement pattern, characterized in that: A central processing unit (5) is provided on one side of the image analyzer (2), and a position adjustment structure (6) and a clamping stabilization mechanism (7) are provided on the inner side of the body (1), wherein the clamping stabilization mechanism (7) is used to clamp and fix the camera lens to prevent the camera lens from vibrating, and the position adjustment mechanism (6) is used to control the clamping stabilization mechanism (7) to accurately move to a position for clamping and fixing the camera lens; Also includes: A lens position capture module (8) is arranged on the inner bottom wall of the body (1) and is used to obtain the position information of the camera lens in real time and transmit it to the central processor (5) for analysis to determine the position of the camera lens; A vibration amplitude acquisition module (9) is arranged on the inner bottom wall of the body (1) and is used to obtain the vibration amplitude of the camera lens at different times within a period of time in real time, and to generate a vibration amplitude variation coefficient through a central processor (5); A vibration frequency acquisition module (10) is arranged on the inner side wall of the mounting seat (3) and is used to acquire the vibration frequency of the camera at different times within a period of time in real time, and to generate a vibration frequency deviation index through a central processing unit (5); The generated vibration amplitude variation coefficient and vibration frequency deviation index are comprehensively analyzed by a central processing unit (5) to generate a vibration judgment coefficient, which is then compared with a preset vibration judgment coefficient reference threshold value. Based on the comparison result, it is determined whether the vibration of the camera lens will affect the SFR test, and the working states of the position adjustment structure (6), the clamping stabilization mechanism (7) and the lens position capture module (8) are controlled based on the comparison result.

2. The camera SFR test device with adjustable focus according to claim 1, characterized in that: The position adjustment mechanism (6) comprises a motor mounting frame (601), a motor (602), a gear transmission box (603), a screw rod (604) and a sliding frame (605); one side of the motor mounting frame (601) is fixedly connected to the inner wall of the machine body (1); the top of the motor mounting frame (601) is fixedly connected to the bottom of the motor (602); the output shaft of the motor (602) is drivingly connected to the input shaft of the gear transmission box (603); the output shaft of the gear transmission box (603) is drivingly connected to one end of the screw rod (604); and the outer wall of the screw rod (604) is drivingly connected to the inner wall of the sliding frame (605).

3. The camera SFR test device with adjustable focus according to claim 2, characterized in that: The clamping stabilization mechanism (7) comprises a cylinder mounting frame (701), a cylinder (702), a telescopic rod (703), an arc-shaped clamping plate (704) and an arc-shaped sponge plate (705); one side of the cylinder mounting frame (701) is fixedly connected to one side of the sliding frame (605); the top of the cylinder mounting frame (701) is fixedly connected to the bottom of the cylinder (702); the output end of the cylinder (702) is transmission-connected to one end of the telescopic rod (703); the other end of the telescopic rod (703) is fixedly connected to one side of the arc-shaped clamping plate (704); and the inner side wall of the arc-shaped clamping plate (704) is fixedly connected to the outer wall of the arc-shaped sponge plate (705).

4. The camera SFR test device with adjustable focus according to claim 3, characterized in that: The output end of the central processing unit (5) is electrically connected to the input end of the motor (602), the input end of the cylinder (702), the input end of the image analyzer (2) and the input end of the measurement pattern generator (4), respectively; the output end of the lens position capture module (8), the output end of the vibration amplitude acquisition module (9) and the output end of the vibration frequency acquisition module (10) are electrically connected to the input end of the central processing unit (5), respectively; the input end of the lens position capture module (8), the input end of the vibration amplitude acquisition module (9) and the input end of the vibration frequency acquisition module (10) are electrically connected to the output end of the central processing unit (5).

5. The camera SFR test device with adjustable focus according to claim 4, characterized in that: The acquisition logic of the vibration amplitude variation coefficient is: S1. The vibration amplitude of the camera lens at different times within a period of time is obtained in real time through the vibration amplitude acquisition module (9), and calibrated as , Indicates that the camera lens is within a period of time The vibration amplitude at the moment, , is a positive integer; S2. Obtain the preset maximum vibration amplitude of the camera lens allowed by the central processor (5) and calibrate it as ; S3. The vibration amplitude of the camera lens at different times within a period of time Create a collection and add the vibration amplitudes in the collection that are greater than the preset maximum The vibration amplitude is recalibrated as , Indicates that the vibration amplitude in the set is greater than the preset maximum The vibration amplitude number, , is a positive integer; S4. Calculate the vibration amplitude variation coefficient. The calculation expression is: In the formula, is the vibration amplitude variation coefficient.

6. The camera SFR test device with adjustable focus according to claim 5, characterized in that: The acquisition logic of the vibration frequency deviation index is: S1. Obtain the vibration frequency of the camera at different times within a period of time in real time through the vibration frequency acquisition module (10), and calibrate it as , Indicates that the camera is in a period of time The vibration frequency of the moment, , is a positive integer; S2. Obtain the preset maximum vibration frequency of the camera allowed by the central processor (5) and calibrate it as ; S3. Calculate the vibration frequency deviation index. The calculation expression is: In the formula, is the vibration frequency deviation index.

7. The camera SFR testing device with adjustable focus according to claim 6, characterized in that: The expression formula of the vibration judgment coefficient is: The central processing unit (5) performs a formula analysis according to the formula: In the formula, is the vibration determination coefficient, and are the vibration amplitude variation coefficients and vibration frequency deviation index The preset scaling factor of and Both are greater than 0.

8. The camera SFR testing device with adjustable focus according to claim 7, characterized in that: Set the preset vibration judgment coefficient reference threshold to , the calculated vibration judgment coefficient is converted into and the preset vibration judgment coefficient reference threshold A comparison is performed, and based on the comparison result, it is determined whether the vibration of the camera lens will affect the SFR test, and based on the comparison result, the working states of the position adjustment structure (6), the clamping stabilization mechanism (7) and the lens position capture module (8) are controlled. The specific determination is as follows: when When the vibration of the camera lens does not affect the SFR test, a normal signal is generated. After receiving the normal signal, the central processing unit (5) generates a standby signal and transmits it to the motor (602), the cylinder (702) and the lens position capture module (8) respectively. After receiving the standby signal, the motor (602) and the cylinder (702) respectively control the position adjustment structure (6) and the clamping stabilization mechanism (7) to perform standby work. After receiving the standby signal, the lens position capture module (8) also performs standby work; when When the camera lens is in a state of vibration, the vibration will affect the SFR test and generate an abnormal signal. After receiving the abnormal signal, the central processing unit (5) generates a capture signal, a movement signal and a clamping signal, and transmits the capture signal to the lens position capture module (8). After receiving the capture signal, the lens position capture module (8) performs a lens position capture operation and transmits the movement signal to the motor (602). After receiving the movement signal, the motor (602) controls the position adjustment structure (6) to perform a position adjustment operation and transmits the clamping signal to the cylinder (702). After receiving the clamping signal, the cylinder (702) controls the clamping stabilization mechanism (7) to perform a clamping stabilization operation.

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