Design method of stray light prevention dustproof film, dustproof film, vehicle-mounted head-up display device and motor vehicle

Abstract

The invention discloses an anti-stray light dustproof film design method, which comprises the following steps of: 1, determining a focus position and a curve parameter of an ellipse corresponding to a dustproof film section curve, and obtaining an elliptic curve equation; 2, performing three-dimensional stretching on the section curve of the dustproof film based on the elliptic curve parameter equation in the step 1 to generate a complete dustproof film curved surface; and 3, extending the front end of the curved surface of the dustproof film and adjusting the included angle to obtain the stray light prevention dustproof film. The invention further discloses the stray light prevention and dust prevention film designed through the method, and the vehicle-mounted head-up display device and / or the motor vehicle provided with the stray light prevention and dust prevention film, and the stray light prevention and dust prevention film has wide application prospects.

Description

Technical Field

[0001] This invention belongs to the field of vehicle head-up display technology, and relates to a design method for an anti-stray light and dustproof film, a dustproof film, a vehicle head-up display device, and a motor vehicle. Background Technology

[0002] Currently, head-up display (HUD) systems have become one of the key technologies for enhancing the driving experience in modern vehicles. HUDs improve driving safety by projecting vehicle information into the driver's field of vision, reducing the frequency with which drivers look down at the instrument panel. However, during HUD development, the design of the dustproof film has become a significant factor affecting display quality and system performance.

[0003] Existing dustproof membrane design methods typically rely on experience and manual adjustments, which leads to the following problems:

[0004] 1. The anti-stray light performance may be insufficient: the existing dustproof film design may not be able to completely block external stray light, especially under strong sunlight or complex lighting conditions, which can easily introduce external stray light from the sky, thereby affecting the readability and contrast of the HUD display content.

[0005] 2. Low development efficiency: Traditional methods require multiple trials and adjustments when designing the surface shape of dustproof films, which is not only time-consuming and labor-intensive, but may also fail to yield the optimal solution.

[0006] 3. Insufficient optical precision: In optical design, the shape of the dustproof film has strict requirements on the light reflection and blocking performance, but existing methods are difficult to meet the high-precision design requirements.

[0007] For example, Chinese invention patent CN115509014B describes a HUD cover device. Although the device can improve the stray light problem to a certain extent, its design fails to make full use of optical laws for optimization, so there may still be problems such as incomplete protection and low efficiency of shape design. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a design method for an anti-stray light and dustproof film, the dustproof film itself, a vehicle head-up display device, and a motor vehicle. Through a dustproof film design method based on elliptical optical properties, the following technical problems are effectively solved:

[0009] 1. 100% blocking of external stray light: By utilizing the optical properties of an ellipse, it ensures that external light sources at all angles reflected by the dustproof film cannot be reflected through the windshield and enter the human eye, thereby effectively blocking external stray light and improving the contrast and readability of the HUD display content.

[0010] 2. Improve development efficiency: By using Catia modeling software to flexibly draw elliptical equation curves based on environmental data, tedious and irregular manual adjustments and multiple optical simulation operations are avoided, significantly shortening the development cycle and improving work efficiency.

[0011] 3. Improve optical accuracy: By precisely drawing the shape of the dustproof film, it can perfectly match the optical path design of the HUD, thereby improving the accuracy of light blocking and reflection, and significantly optimizing the overall display performance of the system.

[0012] By solving the above problems, this invention can not only significantly improve the display effect of HUD, but also shorten the development cycle, providing an efficient and accurate design method for the development of vehicle HUD technology.

[0013] This invention provides a method for designing a light-blocking and dust-proof film, the method comprising:

[0014] Step 1: Determine the focal position and curve parameters of the ellipse corresponding to the profile curve of the dustproof film, and obtain the equation of the ellipse curve; the profile curve of the dustproof film is a part of the ellipse curve, accounting for 1 / 4 to 1 / 6 of the complete ellipse curve, preferably 1 / 5;

[0015] Step 2: Based on the elliptic curve parametric equation in Step 1, perform three-dimensional stretching of the profile curve of the dustproof membrane to generate a complete dustproof membrane surface.

[0016] Step 3: Extend the curved surface of the dustproof film at the front end corresponding to the front direction of the vehicle and adjust the included angle to obtain a dustproof film that prevents stray light.

[0017] In step one, the foci of the elliptic curve include the upper foci and the lower foci;

[0018] The position of the upper focal point is symmetrical about the windshield as the axis of symmetry, and is symmetrical to the observation position at the center of the eye box.

[0019] The position of the lower focal point is where the light from the lowest point of the lower eye box moves on the reflected light from the windshield; the vertical position of the lower focal point does not exceed the vertical range of the reflected light and is lower than the height of the vehicle dashboard; after the vertical position is determined, the lateral position is adjusted within a range of 2-10mm in both the front and rear directions of the vehicle.

[0020] The distance between the upper and lower foci of the elliptic curve is the focal length, denoted as 2c, and the half focal length is c.

[0021] The major axis of the elliptic curve is denoted as 2a, and the semi-major axis is calculated using the following formula:

[0022]

[0023] Where, d maxIt is the maximum value of the total path length from the upper focal point to the reflection point on the curved surface of the dustproof film and from the lower focal point to the reflection point on the curved surface of the dustproof film; in a specific implementation process, the position of the reflection point on the curved surface of the dustproof film can be adjusted and selected to be more suitable.

[0024] The minor axis of the elliptic curve is denoted as 2b, and the semi-minor axis is calculated using the following formula:

[0025]

[0026] The complete equation of the elliptic curve is:

[0027]

[0028] In step two, based on the light emitted from the vehicle head-up display device and its left and right extreme positions, the profile curve of the dustproof film is stretched in the horizontal direction so that the light cannot be observed by the eye box through the position blocked by the dustproof film, thus obtaining a complete dustproof film surface.

[0029] In this invention, the lower focus line formed by connecting the lower focus of the elliptical curve corresponding to the cross-sectional curve of the stretched curved surface is hidden within the vehicle dashboard structure.

[0030] In step three, the dustproof film is extended in the tangential direction at the front end of the curved surface (i.e., in the direction of the front of the vehicle) for a length of 20-50mm, and the angle between the extended part and the horizontal plane is 0.5-1°; preferably, it is 30mm, and the angle is 1° below the horizontal plane.

[0031] In this invention, step three is followed by:

[0032] The dustproof film designed above was simulated and verified based on the vehicle assembly tolerance, simulating the reflection situation in the entire angle range; the vehicle assembly tolerance is ±3mm.

[0033] And / or,

[0034] The surface of the dustproof film was optimized based on the location of the vehicle's dashboard, and the dashboard housing structure was also optimized.

[0035] This invention provides a stray light and dustproof film, which is obtained by the above-described dustproof film design method;

[0036] The anti-stray light and dustproof film is suitable for vehicle head-up display (HUD) systems and has a curved surface structure designed based on elliptical optical properties. The curved surface is determined by the following method:

[0037] The upper focal point is located at the optical reflection point within the driver's eye-viewing range;

[0038] The lower focal point is hidden within the vehicle's dashboard structure to prevent external light from reflecting off that point and entering the driver's line of sight.

[0039] Calculate the major and minor axis dimensions of the ellipse based on the upper and lower focal positions and the limiting beam path of the vehicle HUD optical path.

[0040] Wherein, the elliptical curve containing the cross-sectional curve of the anti-stray light and dustproof film has a straight-line distance between its upper and lower foci of 2c; the radius 'a' of the major axis of the elliptical curve is calculated by the following formula:

[0041]

[0042] Where, d max It is the maximum value of the total path length from the upper focal point to the reflection point on the curved surface of the dustproof film and from the lower focal point to the reflection point;

[0043] The radius b of the minor axis of an elliptic curve is calculated using the following formula:

[0044]

[0045] The complete equation of the elliptic curve is:

[0046]

[0047] And / or,

[0048] The front end of the curved section extends 20-50mm in length and forms an angle of 0.5-1° with the horizontal plane to guide water vapor discharge and improve the vehicle's protective performance in high humidity environments.

[0049] The lower focal point of the dustproof film is designed to overlap with the shielding area of ​​the vehicle's dashboard and housing structure, thereby achieving full-angle blocking of stray light by hiding this point.

[0050] The present invention also provides a vehicle head-up display device, the vehicle head-up display device including the above-mentioned anti-sparkling and dustproof film.

[0051] The present invention also provides a motor vehicle, the motor vehicle including the above-mentioned anti-sparkling and dustproof film or vehicle head-up display device.

[0052] The beneficial effects of this invention include: the dustproof film designed by this invention using elliptical optical properties can block stray light 100%, improving the clarity, contrast and readability of the HUD display; by pre-modeling the shape of the dustproof film, the need for manual adjustment and multiple tests is reduced, and the development cycle is shortened to 50% of the original; the dynamic adjustment design method is applicable to different vehicle models, and the modular design facilitates subsequent iterations. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the dustproof film structure at different angles according to the present invention.

[0055] Figure 2 This is a schematic diagram illustrating the light propagation after the dustproof film is installed according to the present invention.

[0056] Figure 3 This is a schematic diagram illustrating the light propagation situation without the dustproof film installed in this invention.

[0057] Figure 4 This is a schematic diagram illustrating the light propagation after the dustproof film is installed according to the present invention.

[0058] Figure 5 This is a schematic diagram illustrating the propagation of light into the eye box after the dustproof film is installed according to the present invention.

[0059] Figure 6 This is a schematic diagram of the dustproof film structure of the present invention.

[0060] Figure 7 This is a test image of external stray light after the dustproof film is installed in this invention.

[0061] Figure 8 This is another schematic diagram of the structure related to the dustproof film of the present invention.

[0062] Figure 9 This is a side view schematic diagram showing the relationship between the cylinder containing the lower focal line of the present invention and the position of the vehicle IP.

[0063] In the diagram, 1-windshield, 2-lower focal line, 3-dustproof film, 4-instrument panel cover, 5-reflector, 6-eye box, 7-image generation unit, 8-upper focal line. Detailed Implementation

[0064] The present invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. Except for the contents specifically mentioned below, the processes, conditions, and experimental methods for implementing the present invention are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations.

[0065] This invention provides a design method for an anti-stray light and dustproof film. The design method defines the position of the focal bar and optimizes the design of the elliptical curve, enabling the HUD system to effectively prevent glare from entering the human eye and meet the requirements for high precision and high efficiency in preventing stray light.

[0066] like Figure 1 The diagram shows the structure of the dustproof film of the present invention at different angles.

[0067] It should be noted that the complete ellipse shown in the accompanying drawings of this invention is not a solid structure, the cross-sectional curve of the dustproof film surface corresponds only to a part of the ellipse, and the lower focal line 2 referred to in this invention is not a solid structure.

[0068] like Figure 2 The diagram shows the light propagation after the dustproof film is installed according to the present invention. The upper focus 8 of the ellipse and the observation position of the center of the eye box 6 are symmetrical based on the windshield 1.

[0069] Dustproof membrane with elliptical curve design:

[0070] Based on the optical requirements of the HUD system and the position of the vehicle's headlight housing, determine the focal points of the ellipse, namely:

[0071] Upper focal point: obtained symmetrically from the observation position at the center of eye box 6 through windshield 1.

[0072] Lower focal point: Located within the overall IP platform structure, ensuring it is hidden within the Bezel to prevent light from reflecting off the lower focal point and entering the eye box 6.

[0073] Based on the focal position and the limiting beams of the upper and lower eyelids, calculate and determine the major and minor axis dimensions of the ellipse, and draw the ellipse equation curve.

[0074] The calculation methods for the major and minor axes of the ellipse are as follows:

[0075] The focal distance 2c is the straight-line distance between the upper and lower focal points, which can be measured after the position of the lower focal point is determined.

[0076] The major axis (2a) of the ellipse is the maximum diameter of the entire elliptic curve. The formula for calculating the radius a of the major axis is: a = d max / 2, where d max It is the maximum value of the total path length from the upper focal point to the reflection point on the curved surface of the dustproof film and from the lower focal point to the reflection point. And d max Determined by the upper and lower limits of the light source, it can be measured by the maximum optical path distance between the position of the eyepiece and the reflection point of the dustproof film.

[0077] The minor axis of the elliptic curve is denoted as 2b, and the semi-minor axis is calculated using the following formula:

[0078]

[0079] The complete equation of the elliptic curve is:

[0080]

[0081] Based on the light emitted from the vehicle head-up display and its left and right extreme positions, the profile curve of the dustproof film is stretched in the horizontal direction to obtain a complete dustproof film surface.

[0082] Taking into account the actual assembly tolerances of the vehicle, the focal bar's shielding effect is ensured within a tolerance range of ±3mm by stretching the curve of the lower focal point in the same direction.

[0083] Focal Bar Design and Concealment: The Focal Bar (focal line, more specifically, the lower focal line) is defined as a linear extension of the lower focal point of an ellipse. By concealing it inside the vehicle's Bezel (dashboard cover 4), it prevents light from entering the upper focal point 8 after being reflected from the dustproof film 3.

[0084] Specifically, in one embodiment of the present invention, the lower focal line 2 is a straight line passing through the lower focal point. The direction of this straight line is consistent with the stretching direction of the dustproof film 3. Generally, a cylinder with a diameter of 6mm is made using this straight line as the center, defined as the focal bar, and it is ensured that the cylinder can be hidden inside the IP platform. The 6mm diameter is taken into account that the focal line can still be completely hidden even with vehicle assembly tolerances, thereby achieving the effect of the HUD dustproof film in preventing external stray light. Figure 6 As shown.

[0085] This design principle ensures that the dustproof film 3 can completely block stray light from entering the human eye through an elliptical path, thereby solving the glare problem of the HUD system.

[0086] Optical simulation and performance verification:

[0087] Optical simulation was used to observe the light behavior under various sunlight angles at a 300x300mm eye box position, verifying that the dustproof film 3 and Focal Bar design can effectively prevent glare.

[0088] Based on theoretical and simulation verification, ensure that the dustproof film 3 and the vehicle bezel meet the actual assembly requirements.

[0089] like Figure 3 The diagram shown illustrates the light propagation without a dustproof film installed. Figure 4 The diagram shows the light propagation after the dustproof film 3 is installed.

[0090] Vehicle compatibility design:

[0091] The dustproof film 3 needs to be adapted to the overall vehicle structure and IP panel location, and is installed below the dashboard cover 4. To ensure the shielding effect, it is recommended that Bezel's design be optimized in conjunction with the dustproof film surface shape to ensure the accuracy of the HUD light output path and the system's anti-stray light performance.

[0092] In the actual implementation process, the height of the IP panel (dashboard) is increased to ensure that the Focal Bar can be completely hidden.

[0093] The dustproof film and Focal Bar designed by the method of this invention have been verified to effectively prevent glare from entering the eye box under various sunlight angles, significantly improving the contrast and clarity of the HUD display content.

[0094] This method significantly improves the efficiency of dustproof film design and manufacturing, and provides a modular design approach applicable to HUD systems of different vehicle models.

[0095] like Figure 7 The image shown is a test result of external stray light after the dustproof film of this invention has been installed. Figure 7 (a) is a model simulating external stray light. On the left is a 300*300 area at the eye box location, simulating the driver's field of vision. A receiver is set up in this area to receive any external stray light that may enter the eye. The windshield 1 is set to a Lamborghini light source to simulate the situation where external ambient light is reflected after passing through the dustproof film. Figure 7 (b) is an irradiance analysis diagram of the receiver surface, with blue indicating no light.

[0096] like Figure 8 As shown in Figure 9, theoretically, 3D software confirms that the Focal Bar is completely obscured by the Bezel within a ±3mm assembly tolerance.

[0097] like Figure 2 As shown, the focal bar (focal line) is the location of the lower focus of the ellipse. When it is hidden within the vehicle's IP platform structure, light cannot pass through the lower focal point, and therefore cannot be reflected through the dustproof film (part of the ellipse equation) to the upper focal point. The upper focal point is the point symmetrical about the windshield 1 from the eye-viewing position. Therefore, it can be concluded that light cannot be reflected into the human eye, forming stray light. Specifically, when the light from an external light source can pass through the focal line, the reflected light path will definitely pass through the upper focal area. According to the symmetry, the light reflected through the windshield 1 will also inevitably enter the human eye's observation area, i.e., stray light is generated. If the focal line is hidden, the light path of the external light source cannot pass through the focal area and be reflected by the dustproof film, so stray light will not appear. This phenomenon follows the optical properties of an ellipse: that is, light passing through the focal point of an ellipse will definitely pass through the other focal point of the ellipse after being reflected by the inner wall of the ellipse.

[0098] The dustproof film design method based on elliptical optical properties proposed in this invention significantly solves the problems of insufficient anti-stray light performance, low development efficiency, and insufficient optical accuracy in existing technologies by scientifically defining the position of the focal bar and accurately calculating the major and minor axes of the ellipse. The following analyzes the beneficial effects of this invention compared to existing technologies from multiple aspects:

[0099] 1. 100% blocking of external stray light

[0100] Theoretical basis: The dustproof film is designed based on the optical properties of an ellipse (light rays must pass through another focus after being reflected by one focus of an ellipse), and the focal line is hidden within the vehicle's IP platform structure to ensure that external light cannot enter the human eye through reflection of the dustproof film.

[0101] like Figure 5 The diagram shows the propagation of light into the eye box after the dustproof film is installed. The light emitted from the image generation unit 7 continues to propagate after passing through the reflector 5 until it enters the eye box 6.

[0102] Practical results: Compared with the dustproof panels of traditional designs that rely on multiple trials and experience adjustments, the dustproof film of this invention can completely block external stray light from all angles, fundamentally solving the glare problem of HUD systems.

[0103] Simulation verification: Through optical simulation verification, when observed at the position of the 300x300mm eye box, sunlight did not produce any reflection phenomenon in the entire angle range.

[0104] 2. Significantly improved development efficiency

[0105] Existing problems: Traditional methods usually require repeated trials and manual adjustments to complete the dustproof film design, which not only consumes a lot of time but may also increase development costs. Specifically, dustproof films made in the traditional way usually need to undergo optical simulation analysis, modification of the dustproof film curvature, and repeated iterations to finally achieve the goal of avoiding external stray light. Even so, there is still a probability that external stray light cannot be completely eliminated 100%, and the development efficiency and cycle both require a long time.

[0106] Improvements of this invention: By combining the Catia modeling software with the optical path to draw the elliptical surface, the shape of the dustproof film can be quickly drawn by only inputting the upper and lower focal points and the limiting beam parameters, reducing the tedious manual adjustment process.

[0107] Practical results: Development efficiency is improved by about 50% compared with existing technologies, and the design cycle is shortened from 2-3 weeks in the traditional method to less than 1 week, which greatly reduces development time and manpower costs.

[0108] 3. Improved optical accuracy

[0109] Theoretical basis: By calculating the precise major and minor axis parameters of the ellipse, the curved surface of the dustproof film can perfectly match the optical path of the HUD system, achieving high-precision blocking and reflection performance.

[0110] Practical results: Optical simulation results show that the dustproof film produced by this invention can maintain high-efficiency anti-stray light performance under all light angles, avoiding the reflection problem caused by shape errors in existing designs.

[0111] Comparative data: Compared with the traditional HUD protection device in patent CN115509014B, the dustproof film of the present invention has significantly improved the accuracy of stray light blocking and optical performance.

[0112] like Figure 7 As shown, the irradiance on the receiver indicates that the dustproof film designed using this method can 100% avoid external stray light. With the simulated light beam count set to 1 billion, no light beam was observed passing through the receiver.

[0113] 4. Wide range of applications

[0114] Flexible adaptability: This invention can dynamically adjust the ellipse parameters according to the needs of different vehicle models and HUD systems to generate a dustproof film design suitable for specific vehicle environments.

[0115] Enhanced versatility: Through modular design, this approach is applicable to HUD systems in various types of vehicles, facilitating subsequent product upgrades and iterations.

[0116] 5. Optimization of overall vehicle performance

[0117] Structural compatibility: The dustproof film design is integrated with the vehicle's Bezel structure, which not only improves the optical performance of the HUD, but also reduces the accumulation of errors during the vehicle assembly process.

[0118] Performance reliability: Optical verification shows that the dustproof film can maintain high-efficiency anti-stray light performance within a ±3mm assembly tolerance range, and the display effect is not affected by assembly errors.

[0119] In summary, compared with existing technologies, this invention, based on the scientific principles of elliptic optics and precise focal point calculation, offers significant advantages in terms of stray light suppression, development efficiency, optical accuracy, applicability, and vehicle compatibility. These beneficial effects have been fully verified through theoretical calculations and optical simulations, providing an efficient, accurate, and reliable solution for the further development of automotive HUD technology.

[0120] Example 1: Ellipse Equation Plotting and Surface Generation

[0121] 1. Definition of the equation of an ellipse:

[0122] As attached Figure 1 As shown, this invention is based on the optical properties of an ellipse, and determines the curved shape of the dustproof film by defining the focal position of the ellipse.

[0123] The two foci of an ellipse are defined as follows:

[0124] Upper focus: Obtained symmetrically from the eyepiece observation position through the windshield, used to determine the target reflection point of the HUD light.

[0125] Lower focal point: Hidden inside the vehicle's IP panel structure, ensuring that stray light cannot be reflected from the lower focal point and enter the upper focal point.

[0126] 2. Calculation of major and minor axes:

[0127] Based on the actual measurements of the upper and lower focal positions, the focal distance (2c) of the ellipse and the maximum path value (dmax) of the upper and lower limiting beams are determined.

[0128] The calculation formula is:

[0129] Using the calculated major axis radius 'a' and minor axis radius 'b', draw the complete equation of the ellipse:

[0130]

[0131] 3. Curved surface stretching:

[0132] Based on the requirements of the HUD optical path, the elliptical equation curve is input into the Catia software and three-dimensionally stretched to generate a complete dustproof film surface.

[0133] The extended front surface of the dustproof membrane forms a -1° angle with the horizontal plane to ensure that water vapor can be drained.

[0134] Example 2: Concealing the focal line and adapting to the whole vehicle

[0135] 1. Hidden design of the focal line:

[0136] like Figure 2 As shown, the lower focal bar of the ellipse is designed to be hidden inside the vehicle's IP platform structure, ensuring that external light sources will not reflect light into the human eye (upper focal bar) through the lower focal bar when the dustproof film is in its working state after assembly.

[0137] Through simulation verification of the vehicle assembly tolerance (±3mm), even with certain tolerance deviations, the Focal Bar can always be completely blocked by the IP stage and Bezel.

[0138] 2. Vehicle compatibility and optimization:

[0139] The curved shape of the dustproof film is adapted and optimized according to the position of the vehicle's IP platform to ensure a perfect match with the HUD optical path.

[0140] The design of the bezel structure needs to be adjusted according to the curved surface of the dustproof membrane to further improve the shielding performance and assembly stability.

[0141] Example 3: Optical Simulation and Performance Verification

[0142] 1. Optical simulation testing:

[0143] Optical simulation was performed at a 300x300mm eyepiece position to simulate the reflection of sunlight across the entire angular range.

[0144] The verification results show that the dustproof film can effectively block all external stray light, and no reflections enter the eye box.

[0145] 2. Comparative Test:

[0146] Compared with existing HUD protection devices (such as patent CN115509014B), the dustproof film of the present invention significantly improves stray light blocking capability and shielding accuracy.

[0147] Dustproof films using traditional design methods may have light leakage problems at certain angles (such as low incident angles), while the present invention can completely avoid such problems.

[0148] The effect of technological improvements

[0149] 1. Significantly improves anti-stray light performance: The dustproof film, designed with elliptical optical properties, can block 100% of stray light, improving the clarity, contrast and readability of the HUD display.

[0150] 2. Significantly improve development efficiency: Automated modeling reduces the need for manual adjustments and multiple trials, shortening the development cycle to 50% of its original length.

[0151] 3. Enhanced vehicle adaptability: The dynamic adjustment design method is applicable to different vehicle models, and the modular design facilitates subsequent iterations.

[0152] The scope of protection of this invention is not limited to the above embodiments. Any variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of this invention are included in this invention and are protected by the appended claims.

Claims

1. A method for designing an anti-sparkling and dustproof film, characterized in that, The design method includes: Step 1: Determine the focal position and curve parameters of the ellipse corresponding to the dustproof membrane profile curve, and obtain the equation of the ellipse curve; Step 2: Based on the elliptic curve parametric equation in Step 1, perform three-dimensional stretching of the profile curve of the dustproof membrane to generate a complete dustproof membrane surface. Step 3: Extend the front end of the curved surface of the dustproof film and adjust the included angle to obtain the anti-stray dustproof film (3).

2. The design method as described in claim 1, characterized in that, In step one, the foci of the elliptic curve include the upper focus (8) and the lower focus; The position of the upper focal point (8) is symmetrical about the windshield (1) as the axis of symmetry, and is symmetrical about the observation position at the center of the eye box (6); The position of the lower focal point is that the light at the bottom of the lower eye box moves on the reflected light from the windshield (1); the longitudinal position of the lower focal point does not exceed the longitudinal range of the reflected light and is lower than the height of the vehicle dashboard; after the longitudinal position is determined, the lateral position is adjusted within a range of 2-10mm in the front and rear directions of the vehicle. The distance between the upper focus (8) and the lower focus of the elliptic curve is the focal length, denoted as 2c, and the half focal length is c; The major axis of the elliptic curve is denoted as 2a, and the semi-major axis is calculated using the following formula: Wherein, dmax is the maximum value of the total path length from the upper focus (8) to the reflection point of the dustproof membrane surface and from the lower focus to the reflection point of the dustproof membrane surface; The minor axis of the elliptic curve is denoted as 2b, and the semi-minor axis is calculated using the following formula: The complete equation of the elliptic curve is: The profile curve of the dustproof film occupies 1 / 4 to 1 / 6 of the complete elliptical curve.

3. The design method as described in claim 1, characterized in that, In step two, based on the light emitted from the vehicle head-up display device and its left and right extreme positions, the profile curve of the dustproof film is stretched in the horizontal direction to obtain a complete dustproof film surface. The lower focus line, formed by connecting the lower focus of the elliptical curve corresponding to the cross-sectional curve of the stretched surface, is hidden within the vehicle's dashboard structure.

4. The design method as described in claim 1, characterized in that, The dustproof membrane extends tangentially at the front end of the curved surface, with an extension length of 20-50mm and an angle of 0.5-1° between the extended portion and the horizontal plane.

5. The design method as described in claim 1, characterized in that, Step three also includes: The dustproof film (8) designed and generated was simulated and verified based on the vehicle assembly tolerance to simulate the reflection situation in the full angle range; the vehicle assembly tolerance is ±3mm; And / or, The surface of the dustproof film was optimized based on the location of the vehicle's dashboard, and the dashboard housing structure was also optimized.

6. A light-blocking and dust-proof film, characterized in that, The anti-sparkling and dustproof film is obtained by the dustproof film design method as described in any one of claims 1-5; The anti-stray light and dustproof film is suitable for vehicle head-up display (HUD) systems and has a curved surface structure designed based on elliptical optical properties. The curved surface is determined by the following method: The upper focal point is located at the optical reflection point within the driver's eye-viewing range; The lower focal point is hidden within the vehicle's dashboard structure to prevent external light from reflecting off that point and entering the driver's line of sight. Calculate the major and minor axis dimensions of the ellipse based on the upper and lower focal positions and the limiting beam path of the vehicle HUD optical path.

7. The anti-sparkling and anti-dust film as described in claim 6, characterized in that, The elliptical curve containing the cross-sectional curve of the anti-stray light and dustproof film has a focal distance of 2c between its upper and lower focal points. The radius 'a' of the major axis of the elliptic curve is calculated using the following formula: Where dmax is the maximum value of the total path length from the upper focal point to the reflection point on the dustproof film surface and from the lower focal point to the reflection point; The radius b of the minor axis of an elliptic curve is calculated using the following formula: The complete equation of the elliptic curve is:

8. The anti-sparkling and anti-dust film as described in claim 6, characterized in that, The extended portion of the curved front of the dustproof membrane is 20-50mm in length and forms an angle of 0.5-1° with the horizontal plane to guide water vapor discharge.

9. A vehicle-mounted head-up display device, characterized in that, The vehicle head-up display includes an anti-sparkling and anti-dust film (3) as described in any one of claims 6-8.

10. A motor vehicle, characterized in that, The motor vehicle includes the anti-sparkling and dustproof film (3) as described in any one of claims 6-8, or the vehicle head-up display device as described in claim 9.

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