Picture calibration method and device, projector and medium

Abstract

The invention relates to the technical field of projectors, and discloses a picture calibration method and device, a projector and a medium. The method comprises the following steps: acquiring attitude angle information and positioning and orientation information of a projection lens; the positioning and orientation information represents distances and directions of the projection lens relative to at least three non-collinear reference points in a projection plane; determining three-dimensional included angle information between the projection plane and the optical axis of the projection lens based on the attitude angle information and the positioning and orientation information; performing angle calculation on the LCD screen based on the three-dimensional included angle information so as to calculate a target pitch angle value and a target deflection angle value which the LCD screen needs to reach; and driving the screen adjusting component to adjust the angle of the LCD screen by taking the pitch angle and the deflection angle of the LCD screen respectively reaching the target pitch angle value and the target deflection angle value. According to the embodiment of the invention, the projection picture quality of the single-chip LCD projector during side projection can be improved.

Description

Technical Field

[0001] This application relates to the field of projector technology, and in particular to a screen calibration method, device, projector, and medium. Background Technology

[0002] In related technologies, when a single-panel LCD projector performs side projection (i.e., the optical axis of the projector is not parallel to the normal of the projection plane), the distance between the edge of the projection plane and the projection lens and the image distance of the projection lens are prone to deviation, which destroys the ideal imaging conjugate relationship and causes the edge of the projection plane to appear out of focus after focusing at the projection center, which seriously affects the viewing experience. Summary of the Invention

[0003] The purpose of this application is to provide a screen calibration method, device, projector, and medium, which aims to improve the projection image quality of a single-panel LCD projector when performing side projection.

[0004] This application provides a screen calibration method, including: Acquire the attitude angle information and positioning and orientation information of the projection lens; the positioning and orientation information represents the distance and direction of the projection lens relative to at least three non-collinear reference points in the projection plane; Based on the attitude angle information and the positioning and orientation information, the three-dimensional angle information between the projection plane and the optical axis of the projection lens is determined; Based on the three-dimensional angle information, the angle of the LCD screen is calculated to determine the target pitch angle and target yaw angle that the LCD screen needs to achieve. The screen adjustment component is driven to adjust the angle of the LCD screen so that the pitch angle and yaw angle of the LCD screen reach the target pitch angle value and the target yaw angle value, respectively.

[0005] In some embodiments, determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens based on the attitude angle information and the positioning and orientation information includes: Based on the attitude angle information and the positioning and orientation information, the normal vector of the projection plane is determined; The angular deviation between the normal vector of the projection plane and the optical axis direction vector of the projection lens is determined to obtain the optical axis tilt angle information; By decomposing the normal vector of the projection plane, the horizontal deflection angle information and the vertical pitch angle information are obtained; The three-dimensional included angle information is obtained by fitting the optical axis tilt angle information, the horizontal deflection angle information, and the vertical pitch angle information.

[0006] In some embodiments, determining the normal vector of the projection plane based on the attitude angle information and the positioning and orientation information includes: Based on the attitude angle information and the positioning and orientation information, the reference point projection coordinate information in the projection coordinate system of the projection lens is determined; The reference point's projected coordinate information is fitted to a spatial plane, and the normal vector of the projection plane is determined based on the spatial plane fitting result.

[0007] In some embodiments, calculating the angle of the LCD screen based on the three-dimensional angle information includes: The three-dimensional angle information is input into a preset optical geometric transformation model. With the goal of satisfying the object-image conjugate relationship between the LCD screen and the projection plane, the angle of the LCD screen is calculated to obtain the target pitch angle value and the target deflection angle value. The optical geometric transformation model is based on the imaging principle of a convex lens and the internal optical path topology design of the projection lens.

[0008] In some embodiments, the method of driving the screen adjustment component to adjust the angle of the LCD screen includes: Based on the target pitch angle value and the target yaw angle value, generate corresponding control commands; The control command is sent to the screen adjustment component, causing the screen adjustment component to drive the LCD screen to rotate.

[0009] In some embodiments, when the screen adjustment assembly drives the LCD screen to rotate, it further includes: Obtain the measured values ​​of the pitch angle and yaw angle of the LCD screen; When the deviation between the target pitch angle value and the measured pitch angle value exceeds a preset pitch angle deviation threshold and / or the deviation between the target yaw angle value and the measured yaw angle value exceeds a preset pitch angle deviation threshold, the screen adjustment component continues to drive the LCD screen to rotate.

[0010] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described screen calibration method.

[0011] When the screen adjustment assembly drives the LCD screen to rotate, it further includes: Obtain the projection image sharpness information of the projection plane; When the deviation between the projection image clarity information and the target image clarity information exceeds a preset clarity deviation threshold, the screen adjustment component continues to drive the LCD screen to rotate.

[0012] This application also provides a projector, including the above-described electronic device.

[0013] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described screen calibration method.

[0014] The beneficial effects of this application are as follows: By determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens through the attitude angle information and positioning orientation information of the projection lens, the angle of the LCD screen is calculated and adjusted based on this, thereby accurately quantifying the angular deviation between the optical axis of the projection lens and the projection plane. The introduction of the attitude angle information and positioning orientation information of the projection lens provides a solid data foundation for subsequent image calibration, enabling a more accurate understanding of the spatial geometric relationship between the projection lens and the projection plane. Calculating the angle of the LCD screen based on the three-dimensional angle information to determine the target pitch angle and target deflection angle values ​​required by the LCD screen fundamentally changes the relative optical path between the image source and the projection lens, thereby compensating for geometric distortion and defocus caused by side projection and better maintaining the original optical quality of the image. By driving the screen adjustment component to precisely adjust the LCD screen to the target angle, the problem of defocus at the edge of the projected image is effectively solved, significantly improving the overall clarity of the projected image and the user experience, and enhancing the projection image quality of a single-panel LCD projector during side projection. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating the application environment of the screen calibration method provided in the embodiments of this application.

[0016] Figure 2 This is a flowchart of the screen calibration method provided in the embodiments of this application.

[0017] Figure 3 This is a flowchart of a method for determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens, provided in an embodiment of this application.

[0018] Figure 4 This is a flowchart of a method for driving a screen adjustment component to adjust the angle of an LCD screen, as provided in an embodiment of this application.

[0019] Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and drawings are used to distinguish similar objects and are not used to describe a specific order or sequence.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application. All information, data, and signals involved in the embodiments of this application have been authorized by relevant parties or have been fully authorized by all parties, and the collection, use, and processing of related data comply with the relevant laws, regulations, and standards of the relevant countries and regions.

[0023] In side-projection applications of single-panel LCD projectors, when the optical axis of the projection lens is not parallel to the normal of the projection plane, the actual distance between the edge area of ​​the projection plane and the projection lens deviates from the ideal image distance, disrupting the imaging conjugate relationship. Consequently, after focusing in the center area of ​​the projection, the edge areas of the projected image appear out of focus, affecting the overall image clarity. This problem stems from a mismatch between the geometric position of the projection plane and the parameters of the optical system, causing the light propagation path to fail to meet Gaussian optical conditions, thus increasing the size of the blur spot in the edge areas. For example, in a conference room environment, the projector is installed on a side wall, with its optical axis forming a non-perpendicular angle with the whiteboard surface. In this case, the center area of ​​the projected image can display a clear image, but the edges, especially the corners far from the projector, become noticeably blurry, making it difficult for attendees to accurately identify text and graphic details in these areas. Furthermore, this phenomenon is exacerbated when the projection plane is a non-standard rectangle or has local curvature, requiring users to repeatedly adjust the projector position to try to improve edge sharpness, but without fundamentally eliminating the out-of-focus defect.

[0024] If this problem is not resolved, the edge defocusing of the projected image will persist, preventing users from obtaining a complete, clear image and reducing the practicality and reliability of the projection device. Furthermore, persistent image quality defects will interfere with the effective transmission of information, making it impossible to accurately identify key content. In addition, frequent manual focusing operations will increase the user's burden and may affect the structural stability of the device due to repeated adjustments, ultimately weakening the product's market competitiveness.

[0025] Based on this, embodiments of this application provide a screen calibration method, device, projector, and medium. By acquiring attitude angle information and positioning orientation information, the three-dimensional angle information between the projection plane and the optical axis of the projection lens is determined, and the LCD screen angle is calculated and adjusted based on this. This accurately quantifies the angular deviation between the optical axis of the projection lens and the projection plane, effectively solves the problem of out-of-focus projection, and improves the projection image quality of a single-panel LCD projector when performing side projection.

[0026] Figure 1 This diagram illustrates the application environment of the screen calibration method provided in the embodiments of this application. (See also...) Figure 1 This method is applied to an image calibration system. The system includes a terminal 110 and a server 120. The terminal 110 and server 120 are connected via a network. The terminal 110 can be a projector controller (e.g., a projector processor), a desktop terminal, or a mobile terminal. The mobile terminal can be at least one of a mobile phone, tablet, or laptop. The server 120 can be a standalone server or a server cluster consisting of several servers. The terminal 110 sends the attitude angle information and positioning orientation information of the projection lens to the server 120. The positioning orientation information represents the distance and direction of the projection lens relative to at least three non-collinear reference points in the projection plane. The server 120 acquires the attitude angle information and positioning orientation information of the projection lens, determines the three-dimensional angle information between the projection plane and the optical axis of the projection lens based on the attitude angle information and positioning orientation information, and performs angle calculation on the LCD screen based on the three-dimensional angle information to calculate the target pitch angle value and target yaw angle value required by the LCD screen. This ensures that the pitch angle and yaw angle of the LCD screen reach the target pitch angle value and target yaw angle value, respectively, driving the screen adjustment component to adjust the angle of the LCD screen.

[0027] It should be understood that Figure 1 The application scenarios shown are merely examples. In practical applications, the screen calibration method provided in this application embodiment can also be applied to other scenarios. For example, the above-described screen calibration method can be directly applied to terminal 110. Terminal 110 is used to obtain the attitude angle information and positioning orientation information of the projection lens, determine the three-dimensional angle information between the projection plane and the optical axis of the projection lens based on the attitude angle information and positioning orientation information, and perform angle calculation on the LCD screen based on the three-dimensional angle information to calculate the target pitch angle value and target yaw angle value required by the LCD screen, so that the pitch angle and yaw angle of the LCD screen reach the target pitch angle value and target yaw angle value respectively, thereby driving the screen adjustment component to adjust the angle of the LCD screen.

[0028] See Figure 2In one embodiment, a screen calibration method is provided. The subject executing the method may be a terminal or a server, including but not limited to steps S201 to S204.

[0029] Step S201: Obtain the attitude angle information and positioning orientation information of the projection lens.

[0030] A projection lens is an optical component used to project images onto an external plane. It contains a series of lenses that are responsible for converging and diverging light, thereby forming a clear projected image on the projection plane.

[0031] Attitude angle information refers to the attitude data of a projection lens in three-dimensional space, which usually includes pitch angle, roll angle and yaw angle, and is used to describe the tilt and rotation state of the projection lens relative to a certain reference coordinate system.

[0032] Positioning and orientation information characterizes the distance and orientation of the projection lens relative to at least three non-collinear reference points in the projection plane. The projection plane can be understood as the surface on which the projected image is projected, such as a wall, screen, or other plane suitable for displaying the image. Positioning and orientation information refers to the position and orientation data of the projection lens in three-dimensional space relative to the projection plane. Specifically, it characterizes the distance and orientation relationship between the projection lens and at least three non-collinear reference points in the projection plane, thereby determining the spatial geometric relationship between the projection lens and the projection plane.

[0033] Attitude angle information can be provided by an inertial measurement unit (IMU) built into the projector. This IMU integrates sensors such as accelerometers, gyroscopes, and magnetometers to sense and output the pitch, roll, and yaw angles of the projection lens in space in real time. Alternatively, attitude angle information can also be obtained through visual sensors, for example, by analyzing image features of the environment surrounding the projection lens and using image processing algorithms to estimate the spatial attitude of the projection lens.

[0034] Positioning and orientation information characterizes the distance and direction of the projection lens relative to at least three non-collinear reference points on the projection plane. For example, three or more reference points with known locations can be preset on the projection plane, and the distance from the projection lens to these reference points can be measured using a laser rangefinder, ultrasonic sensor, or time-of-flight rangefinder. Simultaneously, combined with the projection lens's own attitude information, the spatial geometric relationship between the projection lens and the projection plane can be constructed. Alternatively, positioning and orientation information can also be obtained through structured light projection and image acquisition; that is, a specific grating pattern is projected onto the projection plane, and the reflected image is captured by a camera, thereby calculating the relative position and direction between the projection lens and the projection plane.

[0035] Step S202: Based on the attitude angle information and positioning orientation information, determine the three-dimensional angle information between the projection plane and the optical axis of the projection lens.

[0036] The optical axis refers to the central axis of the optical system of a projection lens. It is the path of light passing through the lens system under ideal conditions, and its direction determines the center position of the projected image.

[0037] Three-dimensional angle information refers to the relative angle between the projection plane and the optical axis of the projection lens in three-dimensional space. This information quantifies the degree of deviation between the projection optical axis and the normal of the projection plane, and is a key parameter for image calibration.

[0038] Determining the three-dimensional angle between the projection plane and the optical axis of the projection lens can be achieved using geometric principles. This involves converting the lens's attitude angle information into its direction vector in a reference coordinate system, and transforming the positioning and orientation information into the spatial equation of the projection plane. The three-dimensional angle information can then be obtained by calculating the angle between the normal vector of the projection plane and the direction vector of the projection lens's optical axis. For example, if the direction vector of the projection lens's optical axis and the normal vector of the projection plane are known, the angle between them can be calculated using the dot product formula. Alternatively, the three-dimensional angle information can be determined using a pre-established lookup table or empirical model. This lookup table can store the corresponding three-dimensional angle values ​​for different combinations of attitude angles and positioning and orientation information, which can be directly queried by the executing entity during runtime.

[0039] Step S203: Based on the three-dimensional angle information, the angle of the LCD screen is calculated to determine the target pitch angle and target deflection angle that the LCD screen needs to achieve.

[0040] An LCD screen, or liquid crystal display screen, serves as the image source in this embodiment, and its displayed content is projected through a projection lens. By adjusting the angle of the LCD screen, its relative position to the optical path of the projection lens can be changed, thereby correcting the out-of-focus projection image.

[0041] Angle calculation refers to the process of calculating the specific pitch and yaw angles that an LCD screen needs to be adjusted to, based on the input three-dimensional angle information, using a mathematical model or algorithm.

[0042] The target pitch angle and target yaw angle refer to the ideal pitch angle and yaw angle that the LCD screen should achieve after angle adjustment, in order to ensure that the projected image presents the correct clarity on the projection plane.

[0043] Based on this three-dimensional angle information, angle calculation for the LCD screen can be performed by constructing an optical geometric model that describes the optical path relationship between the LCD screen, the projection lens, and the projection plane. Using the determined three-dimensional angle information as input, this model performs inverse calculations to obtain the pitch and yaw angles required for the LCD screen to achieve defocusing, i.e., the target pitch and yaw angle values ​​that the LCD screen needs to achieve. For example, this model can map distorted points on the projection plane back to their corresponding points on the LCD screen based on simple lens imaging formulas and geometric transformation principles, thereby calculating the angles the LCD screen needs to rotate. As an alternative, a mapping relationship can be obtained through experimental calibration. This involves manually adjusting the LCD screen to the optimal display effect under different three-dimensional angle information and recording the pitch and yaw angles at that time, forming an angle mapping database. In practical applications, the executing entity retrieves or interpolates the target pitch and yaw angle values ​​from this database based on the current three-dimensional angle information.

[0044] Step S204: To make the pitch angle and yaw angle of the LCD screen reach the target pitch angle value and the target yaw angle value respectively, the screen adjustment component is driven to adjust the angle of the LCD screen.

[0045] A screen adjustment component is a device used to mechanically adjust the pitch and yaw angles of an LCD screen. It typically consists of a motor, transmission mechanism, and sensors, and can precisely change the spatial orientation of the LCD screen according to control commands.

[0046] When driving the screen adjustment component to adjust the angle of the LCD screen, the calculated target pitch and yaw angle values ​​can be converted into control signals that the screen adjustment component can recognize, such as pulse width modulation (PWM) signals or stepper motor commands. Upon receiving these commands, the screen adjustment component drives its internal actuators (such as stepper motors or servo motors) to precisely rotate the LCD screen to achieve the preset target pitch and yaw angle values. For example, if the target pitch angle is 10 degrees and the target yaw angle is 5 degrees, the screen adjustment component will drive the corresponding motors to rotate the LCD screen 10 degrees along the pitch axis and 5 degrees along the yaw axis. Alternatively, an open-loop control method can be used, where the calculated target angle values ​​are directly sent to the screen adjustment component, and its internal controller adjusts the rotation speed and step size according to preset parameters until the target pitch and yaw angle values ​​are achieved.

[0047] The following example will provide a more detailed explanation of the above technical solution: Suppose user A uses a single-panel LCD projector for side projection at location A. Because the projector's optical axis is not parallel to the normal to the projection plane, the projected image, after focusing at the center, exhibits noticeable out-of-focus areas at the edges, affecting the viewing experience. To address this issue, the image calibration method in this embodiment is activated.

[0048] First, the projector's internal sensor system begins operation. The built-in inertial measurement unit (IMU) acquires the projection lens's attitude angle information in three-dimensional space in real time; for example, the projection lens currently has an upward pitch angle and a leftward yaw angle relative to the horizontal plane. Simultaneously, the projector, through its integrated time-of-flight ranging module, emits lasers towards three pre-set non-collinear reference points on the projection plane and receives the reflected signals, thereby obtaining the distance information from the projection lens to these three reference points. Combining the attitude information provided by the IMU, the actuator can accurately determine the spatial position and orientation of the projection lens relative to these three reference points, thus constructing positioning and orientation information.

[0049] Next, the executing entity uses this attitude angle and positioning / orientation information to determine the three-dimensional angle between the projection plane and the optical axis of the projection lens. Specifically, the executing entity first calculates the spatial equation of the projection plane using a spatial geometric fitting algorithm based on the positioning / orientation information, thereby obtaining the normal vector of the projection plane. Simultaneously, based on the attitude angle information of the projection lens, it determines the direction vector of the projection lens's optical axis in the current coordinate system. Subsequently, the executing entity calculates the angle between the normal vector of the projection plane and the direction vector of the projection lens's optical axis, obtaining a precise three-dimensional angle value. This three-dimensional angle value quantifies the degree of side projection and serves as the basis for subsequent calibration.

[0050] Then, based on this determined three-dimensional angle information, the executing entity calculates the angle of the LCD screen. This three-dimensional angle information is input into a preset optical geometric transformation model. This model considers the internal optical design of the projection lens and the imaging principle of a convex lens, aiming to ensure that the LCD screen and the projection plane maintain an ideal object-image conjugate relationship even under side projection conditions. Through the model's calculations, the executing entity determines the target pitch angle and target deflection angle values ​​required for the LCD screen to eliminate image defocus. For example, the model might calculate that the LCD screen needs to tilt upwards by 2 degrees (target pitch angle value) and rotate to the right by 1 degree (target deflection angle value).

[0051] Finally, the executing unit aims to adjust the LCD screen's tilt and yaw angles to the target values, respectively, by driving the screen adjustment component to adjust the screen's angle. Based on the calculated target angle values, the executing unit generates corresponding control commands and sends these commands to the screen adjustment component. Upon receiving the commands, the screen adjustment component drives its internal micro-motor and precision transmission mechanism to precisely adjust the LCD screen's physical orientation. For example, the screen adjustment component might drive the LCD screen to rotate upwards by 2 degrees and to the right by 1 degree until its tilt and yaw angles reach the target values. Through this series of precise adjustments, the edge defocusing of the projected image on the projection plane is effectively eliminated, resulting in a clearer and sharper overall image, significantly improving user A's viewing experience.

[0052] Based on the above examples, the image calibration method provided in this embodiment demonstrates a significant technical contribution. In the prior art, when a single-panel LCD projector performs side projection, the distance between the edge of the projection plane and the projection lens is prone to deviate from the image distance of the projection lens, thereby disrupting the ideal imaging conjugate relationship and causing out-of-focus images at the edges. This problem is often difficult to solve effectively in traditional solutions, usually requiring users to manually adjust the projector position or sacrifice some image quality.

[0053] This embodiment's method provides a solid data foundation for subsequent image calibration by precisely acquiring the attitude angle and positioning orientation information of the projection lens. Compared to schemes that rely solely on image analysis for coarse calibration, this method can more accurately grasp the spatial geometric relationship between the projection lens and the projection plane. Furthermore, by determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens based on this information, this method quantifies the optical deviation caused by side projection, providing key parameters for precise calibration. This avoids the problem of incomplete calibration or poor results caused by the lack of precise spatial relationship data in traditional methods.

[0054] Crucially, this method calculates the LCD screen's angle based on this three-dimensional angle information to determine the target pitch and deflection angles required for the LCD screen. This strategy of directly adjusting the LCD screen's angle fundamentally alters the relative optical path between the image source and the projection lens, thereby compensating for defocusing caused by side projection. Compared to solutions that rely solely on digital image processing for image correction (which may lead to decreased image resolution or loss of detail), this method, through physical adjustment of the LCD screen, better maintains the original optical quality of the image. Ultimately, by precisely adjusting the LCD screen to the target angle using the screen adjustment components, this method effectively solves the problem of edge defocusing in the projected image, significantly improving the overall clarity of the projected image and the user experience. This technical concept provides a systematic and high-precision side projection image calibration solution, overcoming the limitations of existing technologies in handling complex side projection scenarios.

[0055] See Figure 3 In one embodiment, the method for determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens includes, but is not limited to, steps S301 to S304.

[0056] Step S301: Determine the normal vector of the projection plane based on the attitude angle information and the positioning and orientation information.

[0057] Step S302: Determine the angular deviation between the normal vector of the projection plane and the optical axis direction vector of the projection lens to obtain the optical axis tilt angle information.

[0058] Step S303: Decompose the normal vector of the projection plane to obtain the horizontal deflection angle information and the vertical pitch angle information.

[0059] Step S304: Fit the optical axis tilt angle information, horizontal deflection angle information, and vertical pitch angle information to obtain the three-dimensional included angle information.

[0060] The normal vector of the projection plane uniquely represents its orientation and attitude in three-dimensional space, serving as the basis for subsequent angle calculations. For example, the normal vector can be calculated by obtaining the three-dimensional coordinates of at least three non-collinear points on the projection plane and then using geometric methods such as the cross product of vectors; alternatively, the normal vector of the projection plane can be directly measured and extracted using a specialized planar attitude sensor or depth sensing device.

[0061] Determining the angular deviation between the normal vector of the projection plane and the optical axis vector of the projection lens involves calculating the angle between them. This angle reflects the overall tilt of the projection lens's optical axis relative to the projection plane and is an important macroscopic indicator for assessing projection distortion. For example, the angle can be obtained by calculating the dot product of these two vectors and then using the inverse cosine function; alternatively, the two vectors can be projected onto a common reference plane, and the angle between the projected vectors can be calculated.

[0062] Decomposing the normal vector of the projection plane involves breaking it down into orthogonal horizontal and vertical components within a predefined coordinate system, and then extracting the corresponding angular information. The horizontal deflection angle describes the tilt of the projection plane in the horizontal direction, while the vertical pitch angle describes its tilt in the vertical direction. This decomposition helps simplify complex spatial attitude problems into two independently adjustable dimensions. For example, the normal vector can be projected onto both the horizontal and vertical planes, and then the angles between it and the reference axes can be calculated to obtain the horizontal deflection and vertical pitch angles. Alternatively, attitude representation methods such as Euler angles or quaternions can be used to transform the normal vector from one coordinate system to another and extract the corresponding angular components.

[0063] Fitting the optical axis tilt angle, horizontal deflection angle, and vertical pitch angle information involves using mathematical methods to synthesize these multiple angle information points to obtain a more comprehensive, accurate, and robust overall three-dimensional angle information. This fitting process aims to fuse data from different dimensions, eliminate potential measurement errors, and provide a unified and accurate input for subsequent LCD screen angle calculations. For example, statistical methods such as weighted averaging and least squares can be used to fuse this angle information to eliminate measurement errors and improve overall accuracy; alternatively, a geometric model can be constructed, using this angle information as input parameters, and the model can calculate and output the final three-dimensional angle information.

[0064] This application's solution first precisely determines the normal vector of the projection plane, laying the foundation for subsequent angle calculations. Then, by calculating the angular deviation between this normal vector and the optical axis direction vector of the projection lens, the optical axis tilt angle information is obtained, thus providing a macroscopic description of the overall tilt relationship between the optical axis and the projection plane. To achieve more refined and independent adjustment, the normal vector of the projection plane is further decomposed into horizontal deflection angle information and vertical pitch angle information, which directly correspond to the adjustment degrees of freedom of the LCD screen. Finally, these different but interrelated angle information are fitted, comprehensively considered, and optimized to obtain accurate and robust three-dimensional angle information. This step-by-step refinement and multi-dimensional fusion strategy ensures high precision and high reliability in the conversion process from the original attitude and positioning data to the final three-dimensional angle information, providing a solid data foundation for the subsequent accurate angle calculation and adjustment of the LCD screen.

[0065] The following is a concrete example. Assume the projection lens is equipped with a high-precision inertial measurement unit (IMU) to acquire attitude angle information, and a laser rangefinder measures the distances from the projection lens to three non-collinear reference points on the projection plane. Based on the attitude angle information provided by the IMU and the positioning and orientation information obtained from the laser rangefinder, the three-dimensional coordinates of these three reference points in the projection lens coordinate system can be calculated first. For example, the coordinates of reference points P1, P2, and P3 can be obtained through triangulation or inverse geometry. Then, by calculating the cross product of vectors P1P2 and P1P3, the normal vector of the projection plane can be obtained. Assuming the optical axis direction vector of the projection lens is known in the projection lens coordinate system (e.g., along the positive Z-axis), the dot product of the known projection plane normal vector and this optical axis direction vector, and the inverse cosine, can be used to obtain the optical axis tilt angle information. Next, the normal vector of the projection plane is projected onto the XY plane (horizontal plane) and YZ plane (vertical plane) of the projection lens coordinate system. By calculating the angles between the projection vector and the corresponding coordinate axes, the horizontal deflection angle and vertical pitch angle information can be obtained. For example, the horizontal deflection angle can be determined by the angle between the projection of the normal vector onto the XY plane and the X-axis, and the vertical pitch angle can be determined by the angle between the projection of the normal vector onto the YZ plane and the Y-axis. Finally, data fusion algorithms such as Kalman filtering or extended Kalman filtering can be used to take the optical axis tilt angle, horizontal deflection angle, and vertical pitch angle information as inputs, and perform weighted fusion and optimization, taking into account their respective measurement uncertainties, to obtain a more accurate and robust three-dimensional angle information. This fitting process can effectively reduce the impact of a single measurement error on the final result and provide a comprehensive angle description.

[0066] The above technical solution decomposes the three-dimensional angle information between the projection plane and the optical axis of the projection lens into multiple quantifiable and independently processable dimensions, and then performs comprehensive fitting, effectively improving the accuracy and robustness of the three-dimensional angle information acquisition. This refined angle information determination method can more accurately reflect the projection geometry, providing a more reliable input for subsequent angle calculation of the LCD screen, thereby significantly improving the overall accuracy and effect of image calibration and avoiding problems such as image distortion or incomplete calibration caused by inaccurate angle information.

[0067] In some embodiments, determining the normal vector of the projection plane based on attitude angle information and positioning and orientation information includes: determining the reference point projection coordinate information in the projection coordinate system of the projection lens based on attitude angle information and positioning and orientation information; performing spatial plane fitting on the reference point projection coordinate information; and determining the normal vector of the projection plane based on the spatial plane fitting result.

[0068] Reference point projection coordinate information refers to the transformation of reference point data, obtained through attitude angle information and positioning and orientation information, into three-dimensional coordinate values ​​in the projection coordinate system of the projection lens. This typically involves coordinate transformation; for example, the distance and direction measured by the ranging sensor in its own coordinate system, combined with the attitude angle information of the projection lens, are transformed into the projection coordinate system of the projection lens through a rotation matrix and a translation vector.

[0069] Spatial plane fitting refers to the mathematical process of calculating a plane that best represents a set of points distributed in three-dimensional space. Its purpose is to find an optimally fitting plane using statistical methods, even in the presence of measurement errors, to reduce the impact of errors at individual measurement points on plane determination. Various methods exist for spatial plane fitting. For example, the least squares method can be used to determine the plane equation by minimizing the sum of squared distances from all reference points to the fitted plane. Another method is the Random Sample Consensus (RANSAC) algorithm, which iteratively selects a minimum number of points to fit the plane and statistically counts the number of interior points supporting the plane, robustly finding the optimal plane even with a large number of outliers. Furthermore, Principal Component Analysis (PCA) can be used to determine the principal directions by analyzing the covariance matrix of the point cloud data; the eigenvector corresponding to the minimum principal direction is the normal vector of the plane.

[0070] This application's solution first utilizes the attitude angle and positioning information of the projection lens to accurately locate discrete reference points on the projection plane into the projection coordinate system of the projection lens, thereby transforming the raw sensor data into unified and spatially meaningful three-dimensional coordinate information. Subsequently, spatial plane fitting is performed on the projection coordinate information of these reference points in the projection lens coordinate system. This fitting process effectively filters out possible errors and noise in the measurement of individual reference points, and by integrating the geometric information of multiple points, a mathematical model representing the projection plane is determined in a statistically optimal manner. Finally, based on the spatial plane fitting result, the normal vector of the projection plane is directly extracted. This method avoids the limitations of directly calculating the plane normal vector from a few potentially erroneous points. Instead, by performing a global fitting of multiple points, the determined projection plane normal vector is more accurate and robust, thus providing a more reliable basis for subsequently determining the three-dimensional angle information between the projection plane and the optical axis of the projection lens.

[0071] As a specific implementation, when acquiring the attitude angle information of the projection lens, a miniature inertial measurement unit (IMU) mounted on the projection lens body can be used. This IMU can output the pitch, yaw, and roll angle data of the projection lens in real time. Simultaneously, multiple laser rangefinders can be used to measure the distance to at least three pre-set non-collinear reference points on the projection plane, acquiring positioning and orientation information. These reference points can be pre-marked reflective points on the projection plane to improve ranging accuracy. Then, the attitude angle information provided by the IMU is combined with the positioning and orientation information provided by the laser rangefinders. Through a pre-set coordinate transformation algorithm, the distance and direction information of each reference point in the laser rangefinder coordinate system is transformed and represented as three-dimensional coordinates in the projection coordinate system of the projection lens, forming the reference point projection coordinate information. For example, if the laser rangefinder is located next to the projection lens, its measurement results can be combined with the attitude of the projection lens and transformed to the projection lens coordinate system through a rotation matrix and translation vector. Then, the transformed reference point projection coordinate information can be fitted to the spatial plane using the least squares method. Specifically, an objective function is constructed, representing the sum of squared distances from all reference points to the plane to be fitted. The parameters of the plane (e.g., A, B, C, D in the plane equation Ax + By + Cz + D = 0) are determined by finding the minimum value of this objective function. Once the equation of the fitted plane is obtained, the normal vector (A, B, C) of the plane can be directly determined and further normalized to a unit normal vector.

[0072] The above technical solution utilizes attitude angle and positioning information to accurately map discrete reference points into the projection coordinate system of the projection lens. Furthermore, it determines the normal vector of the projection plane through spatial plane fitting, effectively overcoming the influence of errors and noise from individual measurement points on the normal vector calculation. This method, by integrating measurement data from multiple reference points, determines the direction of the projection plane in a statistically optimal manner, significantly improving the accuracy and robustness of the projection plane normal vector determination. Therefore, the determined projection plane normal vector is more stable and reliable, laying a solid foundation for the subsequent accurate calculation of the three-dimensional angle information between the projection plane and the optical axis of the projection lens. This enhances the accuracy and stability of the entire image calibration method, ensuring a more ideal calibration effect for the final projected image.

[0073] In some embodiments, angle calculation of the LCD screen based on three-dimensional angle information includes: inputting the three-dimensional angle information into a preset optical geometric transformation model, with the goal of making the LCD screen and the projection plane satisfy the object-image conjugate relationship, and performing angle calculation on the LCD screen to obtain the target pitch angle value and the target deflection angle value.

[0074] The optical geometric transformation model is derived from the imaging principle of a convex lens and the internal optical path topology design of a projection lens. It can be understood as a mathematical model describing the propagation path and imaging laws of light in an optical system. This model can correlate geometric relationships in physical space (e.g., the three-dimensional angle between the projection plane and the optical axis of the projection lens) with imaging parameters within the optical system (e.g., the angle of the LCD screen). One possible implementation is a matrix transformation-based optical model, establishing coordinate system transformation relationships between the projection lens, LCD screen, and projection plane, and deriving angle calculation formulas using geometric optics principles. Another implementation is a ray-tracing-based model, simulating the path of light emitted from the LCD screen, passing through the projection lens, and finally reaching the projection plane, thus deducing the optimal angle of the LCD screen. The optical geometric transformation model is established based on actual physical laws and specific hardware structures, rather than simple empirical formulas, thereby ensuring the accuracy and reliability of the calculation results. The imaging principle of a convex lens is fundamental to geometric optics, describing the refraction of light after passing through it. The internal optical path topology design of a projection lens refers to the specific structural parameters such as the arrangement, material, and curvature of the lens groups within the lens. For example, a precise mathematical model can be constructed by modeling the projection lens using optical design software (such as Zemax or Code V), inputting parameters like the focal length, radius of curvature, and refractive index of the convex lens, and combining these with the lens arrangement and aperture position within the lens's topology to simulate the light path. Alternatively, experimental measurements and data fitting can be used to measure the projection effect at different angles based on the known imaging principle of a convex lens, and then, by combining this with the structural parameters of the projection lens, a realistic optical geometric transformation model can be derived.

[0075] Object-image conjugate relationship refers to the one-to-one correspondence between an object and its image point in optical imaging. That is, a point on an object, after passing through an optical system, forms a sharp image point on the image plane. Its purpose is to ensure that the projected image is sharp and distortion-free on the projection plane, achieving optimal image quality. Specifically, this means that each pixel on the LCD screen, after passing through the projection lens, can be accurately mapped to its corresponding position on the projection plane, with the focal point located on the projection plane. Furthermore, by adjusting the parameters of the optical system (such as focal length, object distance, and image distance) and the angle of the LCD screen, the image formed by the projection lens on the LCD screen can be made to fall precisely on the projection plane, thus satisfying the conjugate condition.

[0076] The proposed solution uses externally measured three-dimensional angle information as input parameters into a pre-established optical geometric transformation model. This model is not a simple empirical formula, but rather constructed based on rigorous convex lens imaging principles and the actual internal optical path topology design of the projection lens. This means the model can accurately reflect the propagation and imaging characteristics of light in the projection system. Through this model, the execution entity can perform precise angle calculations with the goal of satisfying the object-image conjugate relationship between the LCD screen and the projection plane. The object-image conjugate relationship ensures that the image on the LCD screen can be projected onto the projection plane clearly and without distortion, thereby obtaining the target pitch and deflection angle values ​​required by the LCD screen. This calculation method based on physical models and optical principles overcomes the potential inaccuracies of traditional empirical calculations, ensuring the accuracy of image calibration and projection quality.

[0077] As a specific implementation, the optical geometric transformation model can be a mathematical model based on ray tracing algorithms and matrix optics theory. This model first establishes coordinate systems for the projection lens, the LCD screen, and the projection plane, defining their relative positions and orientations. Then, based on the specific optical design parameters of the projection lens (e.g., focal length of the lens group, radius of curvature of each lens, refractive index, and aperture position), ray tracing is used to simulate the path of light rays emitted from specific pixels on the LCD screen, passing through the projection lens, and reaching the projection plane. Through iterative calculations or optimization algorithms, the pitch and deflection angles of the LCD screen are adjusted until all pixels on the LCD screen form a clear, focused image on the projection plane, satisfying the object-image conjugate relationship. For example, an optimization objective function can be set, which measures the sharpness or distortion of the projected image on the projection plane. Then, through gradient descent or other optimization methods, the optimal combination of LCD screen angles that achieves the objective function is found, thus obtaining the target pitch and deflection angle values.

[0078] Through the above technical solution, this application can accurately convert three-dimensional angle information into the target adjustment angle of the LCD screen by utilizing an optical geometric transformation model based on the imaging principle of a convex lens and the internal optical path topology design of the projection lens. This method ensures that the object and image conjugate relationship is satisfied between the LCD screen and the projection plane, thereby significantly improving the accuracy of image calibration and the clarity of the projected image. It effectively solves the problem of inaccurate angle calculation in complex optical systems using traditional methods, providing users with a high-quality projection experience.

[0079] See Figure 4 In one embodiment, the method of driving the screen adjustment component to adjust the angle of the LCD screen includes, but is not limited to, steps S401 to S402.

[0080] Step S401: Generate corresponding control commands based on the target pitch angle and target yaw angle values.

[0081] In step S402, a control command is sent to the screen adjustment component, causing the screen adjustment component to drive the LCD screen to rotate.

[0082] The solution in this application uses the target pitch angle and target yaw angle values ​​calculated in the aforementioned steps as input. First, the executing entity generates a series of specific, executable control commands based on these target angle values, combined with the characteristics of the screen adjustment component and the control protocol. These control commands are a language that the screen adjustment component can understand and translate into mechanical actions. Subsequently, these generated control commands are precisely sent to the screen adjustment component. After receiving the commands, the internal drive mechanism of the screen adjustment component precisely drives the LCD screen to physically rotate according to the requirements of the commands. In this way, the pitch angle and yaw angle of the LCD screen can be precisely adjusted to achieve the preset target pitch angle and target yaw angle values, respectively. This process transforms abstract geometric calculation results into actual physical adjustments, ensuring that the LCD screen can project in the optimal posture, thereby solving the problem of how to effectively translate the calculated target angle values ​​into actions that the screen adjustment component can execute.

[0083] In one specific implementation, after obtaining the target pitch and yaw angle values, a microcontroller can generate control commands. This microcontroller internally stores a mapping relationship between angle values ​​and motor drive signals (such as PWM pulse width or stepper motor pulse sequences). Upon receiving the target pitch and yaw angle values, the microcontroller calculates the specific number of pulses or PWM signal parameters required to drive the pitch and yaw motors in the screen adjustment component based on these mapping relationships. Subsequently, the microcontroller sends these calculated control commands as electrical signals to the screen adjustment component via its GPIO ports or dedicated communication interface. The screen adjustment component integrates a motor driver and two independent stepper motors: one for controlling the pitch rotation of the LCD screen, and the other for controlling the yaw rotation. When the driver receives the pulse signal sent by the microcontroller, it precisely controls the corresponding stepper motor to rotate the corresponding number of steps, thereby driving the LCD screen to reach the target pitch and yaw angle values.

[0084] Through the above technical solution, this application provides an effective mechanism for converting the calculated target pitch angle and target deflection angle values ​​into executable actions of the screen adjustment components. This ensures that the LCD screen can physically adjust according to the precisely calculated target angle, thereby achieving accurate calibration of the projected image. This solution makes the attitude adjustment process of the LCD screen controllable and precise, avoiding inaccurate or inefficient adjustments due to a lack of specific execution instructions, thus ensuring the clarity and geometric accuracy of the projected image.

[0085] In some embodiments, when the screen adjustment component drives the LCD screen to rotate, the method further includes: acquiring the measured values ​​of the pitch angle and yaw angle of the LCD screen; and maintaining the screen adjustment component driving the LCD screen to rotate when the deviation between the target pitch angle value and the measured pitch angle value exceeds a preset pitch angle deviation threshold and / or the deviation between the target yaw angle value and the measured yaw angle value exceeds a preset pitch angle deviation threshold.

[0086] Obtaining the measured pitch and yaw angles of the LCD screen refers to real-time monitoring and acquisition of the screen's current actual pitch and yaw angles. This can be achieved by integrating angle sensors into the LCD screen or its adjustment mechanism. For example, a microelectromechanical system (MEMS) inertial measurement unit (IMU) can be used, which integrates a gyroscope and accelerometer, enabling high-precision measurement of the screen's attitude angles. Alternatively, sensors such as optical encoders or magnetic encoders can be used to directly measure the rotation angle of the screen's adjustment components, thereby calculating the LCD screen's actual pitch and yaw angles. These measured values ​​form the basis for closed-loop control, used to determine whether the screen has reached the target position.

[0087] Pitch angle deviation thresholds and yaw angle deviation thresholds define the acceptable error range. These can be set according to the calibration accuracy requirements of the actual application scenario; for example, they can be set to 0.1 degrees or less. When the deviation between the measured value and the target value exceeds these thresholds, the actuator determines that the screen is not yet in position or has not reached the required accuracy, thus maintaining the drive state of the screen adjustment component to continue moving it towards the target angle. This mechanism ensures that the screen adjustment process has feedback and correction capabilities until the expected precise position is reached.

[0088] This application's solution introduces a real-time feedback mechanism, transforming the LCD screen adjustment process from a simple unidirectional drive into a closed-loop control system. Specifically, when the screen adjustment component begins to drive the LCD screen to rotate based on preset target pitch and deflection angle values, the actuator simultaneously acquires the measured pitch and deflection angle values ​​of the LCD screen. These measured values ​​are compared with the target values ​​in real time. Once the deviation exceeds a preset allowable threshold, the actuator maintains the drive state of the screen adjustment component. This means that even if mechanical errors, changes in frictional resistance, or external disturbances occur during the adjustment process, causing the screen to fail to reach the target position precisely in one go, the actuator can ensure that the screen ultimately converges precisely to the target angle through continuous drive and feedback correction. This continuous, deviation-based drive maintenance mechanism effectively overcomes the potential accuracy deficiencies of traditional open-loop control, significantly improving the accuracy and reliability of screen calibration.

[0089] The following is a concrete example. When the screen adjustment component drives the LCD screen to rotate, a high-precision MEMS inertial measurement unit (IMU) can be used to acquire the measured values ​​of the LCD screen's pitch and yaw angles in real time. These measured data are transmitted to a microcontroller or digital signal processor (DSP). This processor internally runs a proportional-integral-derivative (PID) controller algorithm. The PID controller continuously calculates the errors between the target pitch angle and the measured pitch angle, and between the target yaw angle and the measured yaw angle. When the absolute value of the error at any angle exceeds a preset threshold of 0.05 degrees, the PID controller generates a corresponding control signal (e.g., a pulse width modulation (PWM) signal) based on the magnitude and trend of the error, and sends it to the stepper motor or servo motor driven by the screen adjustment component. Upon receiving the control signal, these motors continue to rotate at an appropriate speed and direction, thereby driving the LCD screen to make fine adjustments. This process continues until the measured values ​​of the pitch and yaw angles are both within ±0.05 degrees of their respective target values. At this point, the PID controller will stop or reduce the drive signal to stabilize the screen at the target position.

[0090] Through the above technical solution, this application can significantly improve the accuracy and stability of LCD screen angle adjustment. By monitoring the actual screen angle in real time and comparing it with the target angle, and deciding whether to maintain drive based on the magnitude of the deviation, the influence of factors such as mechanical transmission errors, sensor measurement errors, and external interference on adjustment accuracy can be effectively compensated. This ensures that the LCD screen can accurately reach the calculated target pitch angle and target deflection angle values, thereby achieving more accurate image calibration and improving the quality of the projected image and user experience.

[0091] In some embodiments, when the screen adjustment component drives the LCD screen to rotate, the method further includes: acquiring projection image clarity information of the projection plane; and maintaining the screen adjustment component driving the LCD screen to rotate when the deviation between the projection image clarity information and the target image clarity information exceeds a preset clarity deviation threshold.

[0092] Obtaining projection image sharpness information on a projection plane refers to acquiring data reflecting the level of image sharpness projected onto the projection plane. This information can be used to assess the actual display quality of the current projection image and serve as feedback for subsequent correction processes. Acquisition methods may include, but are not limited to: capturing the projection image using an optical sensor or image acquisition device (e.g., a camera) positioned near the projection plane and analyzing the image's brightness distribution, grayscale differences, etc., through image processing algorithms to quantify the sharpness value; or directly measuring the brightness differences in a specific area on the projection plane using a specialized sharpness measurement instrument.

[0093] The sharpness deviation threshold defines the acceptable range of image sharpness, which can be set according to the required image sharpness accuracy in the actual application scenario. When the deviation between the projected image sharpness information and the target image sharpness information exceeds the sharpness deviation threshold, it indicates that the current LCD screen angle has not reached the target angle or has reached the target angle but still has image blurriness. The execution unit will determine that the screen is not yet in position or has not achieved the required image sharpness, thereby maintaining the drive state of the screen adjustment components and causing them to continue moving towards the target angle. This mechanism ensures that the screen adjustment process has feedback and correction capabilities until the expected precise position is reached.

[0094] The following is a concrete example. When the screen adjustment component drives the LCD screen to rotate, an optical sensor or image acquisition device (e.g., a camera) can be used to acquire a real-time image of the projection plane. This image is transmitted to a microcontroller or digital signal processor (DSP). The processor internally runs an image analysis algorithm to determine the sharpness information of the projected image on the projection plane. The execution unit continuously calculates the deviation between the projected image sharpness information and the target image sharpness information. When the deviation exceeds a sharpness deviation threshold, the execution unit generates a corresponding control signal (e.g., a pulse width modulation (PWM) signal) based on the magnitude of the deviation and sends it to the stepper motor or servo motor driven by the screen adjustment component. Upon receiving the control signal, these motors continue to rotate at an appropriate speed and direction, thereby driving the LCD screen to make fine adjustments. This process continues until the deviation between the projected image sharpness information and the target image sharpness information does not exceed the sharpness deviation threshold. At this point, the execution unit stops or reduces the drive signal, stabilizing the LCD screen at the target position.

[0095] Through the above technical solution, this application introduces a feedback correction mechanism based on image sharpness information. This mechanism can effectively compensate for the impact of factors such as mechanical transmission errors, sensor measurement errors, and external interference on the sharpness of the projected image. By comparing the sharpness of the actual projected image with the theoretically predicted sharpness, and fine-tuning the LCD screen accordingly, the accuracy of image calibration is improved, optimizing the final projected image's sharpness, clarity, and other visual effects, thereby providing users with a higher quality projection experience.

[0096] Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application. The following refers to... Figure 5 To describe an electronic device 500 according to such an embodiment of the present disclosure. Figure 5 The electronic device 500 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0097] like Figure 5 As shown, the electronic device 500 is presented in the form of a general-purpose computing device. The components of the electronic device 500 may include, but are not limited to: at least one processing unit 510, at least one storage unit 520, a bus 530 connecting different system components (including storage unit 520 and processing unit 510), a display unit 540, etc.

[0098] The storage unit stores program code, which can be executed by the processing unit 510, causing the processing unit 510 to perform the steps described in the above-described screen calibration method section of this specification according to various exemplary embodiments of this disclosure.

[0099] Storage unit 520 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 5201 and / or cache memory 5202, and may further include a read-only memory (ROM) 5203.

[0100] Storage unit 520 may also include a program / utility 5204 having a set (at least one) program module 5205, such program module 5205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0101] Bus 530 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0102] Electronic device 500 can also communicate with one or more external devices 500' (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 500, and / or with any device that enables electronic device 500 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 550. Furthermore, electronic device 500 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 560. Network adapter 560 can communicate with other modules of electronic device 500 via bus 530. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 500, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0103] This application also provides a projector that includes the electronic device described above.

[0104] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0105] The image calibration method, device, projector, and medium provided in this application determine the three-dimensional angle information between the projection plane and the optical axis of the projection lens by using the attitude angle information and positioning orientation information of the projection lens. Based on this, the angle of the LCD screen is calculated and adjusted, thereby accurately quantifying the angular deviation between the optical axis of the projection lens and the projection plane. By introducing the attitude angle information and positioning orientation information of the projection lens, a solid data foundation is provided for subsequent image calibration, enabling a more accurate understanding of the spatial geometric relationship between the projection lens and the projection plane. Angle calculation of the LCD screen based on the three-dimensional angle information, to calculate the target pitch angle and target deflection angle values ​​required by the LCD screen, fundamentally changes the relative optical path between the image source and the projection lens, thereby compensating for geometric distortion and defocus caused by side projection and better maintaining the original optical quality of the image. By driving the screen adjustment component to precisely adjust the LCD screen to the target angle, the problem of defocus at the edge of the projected image is effectively solved, significantly improving the overall clarity of the projected image and the user experience, and enhancing the projection image quality of a single-panel LCD projector during side projection.

[0106] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the methods described above according to the embodiments of this disclosure.

[0107] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0108] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0109] Those skilled in the art will understand that the above modules can be distributed in the device as described in the embodiments, or they can be modified accordingly and placed in one or more devices that are unique to this embodiment. The modules in the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.

[0110] Exemplary embodiments of this disclosure have been specifically shown and described above. It should be understood that this disclosure is not limited to the detailed structures, arrangements, or implementations described herein; rather, this disclosure is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims.

Claims

1. A picture calibration method, characterized by, The method comprises: obtaining attitude angle information and positioning and orientation information of a projection lens; the positioning and orientation information represents the distance and direction of the projection lens relative to at least three non-collinear reference points in a projection plane; based on the attitude angle information and the positioning and orientation information, determining three-dimensional angle information between the projection plane and the optical axis of the projection lens; based on the three-dimensional angle information, performing angle calculation on an LCD screen to calculate target pitch angle and target yaw angle values required to be reached by the LCD screen; driving a screen adjusting assembly to adjust the angle of the LCD screen, so that the pitch angle and the yaw angle of the LCD screen reach the target pitch angle and the target yaw angle values respectively.

2. The picture calibration method of claim 1, wherein, The method comprises: based on the attitude angle information and the positioning and orientation information, determining the normal vector of the projection plane; determining the angle deviation value between the normal vector of the projection plane and the optical axis direction vector of the projection lens to obtain optical axis tilt angle information; decomposing the normal vector of the projection plane to obtain horizontal yaw angle information and vertical pitch angle information; fitting the optical axis tilt angle information, the horizontal yaw angle information and the vertical pitch angle information to obtain the three-dimensional angle information.

3. The picture calibration method of claim 2, wherein, The method comprises: based on the attitude angle information and the positioning and orientation information, determining the reference point projection coordinate information of the reference points in the projection coordinate system of the projection lens; performing spatial plane fitting on the reference point projection coordinate information, and determining the normal vector of the projection plane based on the spatial plane fitting result.

4. The picture calibration method of claim 1, wherein, The method comprises: inputting the three-dimensional angle information into a preset optical geometric transformation model to perform angle calculation on the LCD screen, so that the LCD screen and the projection plane satisfy the object-image conjugate relationship, and obtain the target pitch angle and the target yaw angle values; the optical geometric transformation model is obtained based on the convex lens imaging principle and the internal optical path topology design of the projection lens.

5. The picture calibration method of claim 1, wherein, The method comprises: generating corresponding control instructions based on the target pitch angle and the target yaw angle values; sending the control instructions to the screen adjusting assembly to drive the LCD screen to rotate.

6. The picture calibration method of claim 5, wherein, When the screen adjusting assembly drives the LCD screen to rotate, the method further comprises: obtaining the pitch angle measured value and the yaw angle measured value of the LCD screen; when the deviation value between the target pitch angle value and the pitch angle measured value exceeds the preset pitch angle deviation threshold value and / or the deviation value between the target yaw angle value and the yaw angle measured value exceeds the preset pitch angle deviation threshold value, maintaining the screen adjusting assembly to drive the LCD screen to rotate.

7. The picture calibration method of claim 5, wherein, When the screen adjusting assembly drives the LCD screen to rotate, the method further comprises: acquire projection picture definition information of the projection plane; when a deviation between the projection picture definition information and target picture definition information exceeds a preset definition deviation threshold, maintaining the screen adjusting component to drive the LCD screen to rotate.

8. An electronic device, comprising: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor implements the picture calibration method in any one of claims 1 to 7 when executing the computer program.

9. A projector characterized by comprising: The electronic device comprises the picture calibration method in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 9. The computer program is executed by the processor to implement the picture calibration method in any one of claims 1 to 7.

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