Angle calculation method and panoramic head-up display system

Abstract

The invention relates to an angle calculation method and a panoramic head-up display system, the panoramic head-up display system comprises windshield glass, a display screen and a polarization unit, the plane where the polarization unit is located is parallel to the plane where the display screen is located, and the method comprises the following steps: according to three non-collinear points on the surface of the display screen, calculating the angle of the display screen; calculating a normal vector of a display plane of the display screen; calculating the direction vector of P polarized light according to the normal vector of the reflection plane and the direction vector of the incident light; drawing a vertical line vertical to the incident light in the reflection plane, taking the projection of the vertical line in the display screen as a projection line, and calculating the direction vector of the projection line; acquiring two points longitudinally arranged along a display area of the display screen, and calculating a reference vector; and calculating the angle theta of the polarization unit according to the direction vector and the reference vector of the projection line. According to the technical scheme, the problem that the utilization rate of P polarized light is not high due to the fact that a polarization unit is directly rotated by 90 degrees and then attached to the surface of a display screen in a traditional scheme can be solved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an angle calculation method and a panoramic head-up display system. Background Technology

[0002] A panoramic head-up display (P-HUD) is an advanced in-vehicle display technology that generates images through a projection unit (PGU) and projects these images onto the windshield or a separate transparent panel using an optical reflection system. This creates a virtual image that floats in front of the vehicle, allowing the driver to obtain driving information without looking down. It consists of a display screen, an optical reflection system, display units, and a control module. Its working principle involves reflecting images into the driver's field of vision through optical reflection and optical path design. Its optical principles are based on virtual image imaging, optical path design, and reflection and transmission. This system improves driving safety and convenience.

[0003] Because the incident angle of light from a P-HUD is close to the Brewster angle (approximately 57°) of a car windshield, near this angle, the windshield reflects almost no P-polarized light, but has a high reflectivity for S-polarized light. To improve light utilization, most manufacturers use only S-polarized light as the light source. However, polarized sunglasses block S-polarized light to prevent glare, thus severely affecting image visibility when worn. The traditional approach is to directly rotate the polarization unit 90° and attach it to the surface of the display screen to enhance P-polarized light reflection and suppress S-polarized light reflection, but this method has low utilization of P-polarized light. Summary of the Invention

[0004] This application provides an angle calculation method and a panoramic head-up display system to solve the problem that the traditional solution directly rotates the polarization unit by 90° and attaches it to the surface of the display screen to enhance the reflection of P-polarized light and suppress the reflection of S-polarized light, but the utilization rate of P-polarized light is not high.

[0005] In a first aspect, this application provides an angle calculation method applied to a panoramic head-up display system, the panoramic head-up display system including a windshield, a display screen, and a polarization unit, wherein the plane of the polarization unit is arranged parallel to the plane of the display screen, and includes the following steps: Calculate the normal vector of the display plane of the display screen based on three non-collinear points on the display surface. ; According to the normal vector of the reflection plane and the direction vector of the incident ray Calculate the direction vector of P-polarized light. ; According to the definition of P-polarized light, a perpendicular line is drawn in the reflecting plane to the incident light ray. The projection of this perpendicular line onto the display screen is called a projection line. The direction vector of the projection line is then calculated. ; Two points are set along the vertical direction of the display area of ​​the screen, and a reference vector is calculated. ; According to the direction vector of the projection line and the reference vector Calculate the rotation angle θ of the polarization unit.

[0006] Optionally, the normal vector of the display plane of the display screen is calculated based on three non-collinear points on the surface of the display screen. This includes: determining three non-collinear points on the surface of the display screen, then ; in, Let be the coordinates of three non-collinear points on the surface of the display screen.

[0007] Optionally, the step based on the normal vector of the reflection plane... and the direction vector of the incident ray include: Obtain the coordinates of the intersection point between the main optical path and the windshield. Coordinates of the center point of the eye ellipse The screen displays the coordinates of the center point of the area. ; Calculate the normal vector of the reflecting plane: .

[0008] Optionally, the direction vector of the incident light ray .

[0009] Optionally, the step based on the normal vector of the reflection plane... and the direction vector of the incident ray Calculate the direction vector of P-polarized light. include: According to the direction of P-polarized light on the reflecting plane Inner and with vector If perpendicular, then the direction vector of the P-polarized light is... .

[0010] Optionally, according to the formula for projecting a vector onto a plane, the direction vector of the projection line is... The calculation formula is as follows:

[0011] in, Let be the direction vector of P-polarized light. Let be the normal vector of the display plane of the display screen.

[0012] Optionally, the step of obtaining two points along the longitudinal direction of the display area on the screen and calculating the reference vector is performed. This includes: the display screen has two points, point A and point B, set longitudinally along the display area. .

[0013] Optionally, the step of determining the direction vector of the projection line... and the reference vector Calculating the rotation angle θ of the polarization unit includes: According to the formula for calculating the angle between spatial vectors:

[0014] The formula for calculating the rotation angle θ of the polarization unit is as follows:

[0015] in, Let be the direction vector of the projection line. is the reference vector on the display screen.

[0016] Secondly, this application provides a panoramic head-up display system that employs the angle calculation method provided in the first aspect of this application, including: Windshield; A display screen capable of emitting light that is projected onto the windshield, the windshield being used to reflect the light to the human eye for imaging; A polarization unit is located on the optical path from the display screen to the windshield. The plane of the polarization unit is parallel to the plane of the display screen. The polarization direction of the polarization unit is set at the rotation angle θ with the direction from the bottom to the top of the display screen. The polarization unit enables P-polarized light emitted from the display screen to be projected onto the windshield.

[0017] Optionally, the windshield has a reflective portion located at one end of the windshield near the display screen, the reflective portion being used to reflect the light projected by the display screen.

[0018] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides an angle calculation method applied to a panoramic head-up display (P-HUD) system. The system includes a windshield, a display screen, and a polarization unit, wherein the plane containing the polarization unit is parallel to the plane containing the display screen, forming a complete incident-reflection-imaging optical path. This application calculates the direction vector of P-polarized light using the normal vector of the reflecting plane and the direction vector of the incident ray. According to the definition of P-polarized light, a vertical line perpendicular to the incident ray is drawn in the reflecting plane; the projection of this vertical line onto the display screen is called a projection line, and the direction vector of this projection line is calculated. Using the normal vector and reference vector of the display screen's display plane, the angle θ between the polarization direction of the polarization unit and the display screen along the longitudinal direction of the display area is calculated. Through precise calculation, this application can obtain the polarization unit rotation angle θ that achieves the maximum reflectivity of P-polarized light. This ensures that P-polarized light can be efficiently reflected into the driver's line of sight, significantly improving the driver's visibility when wearing polarized sunglasses, thereby enhancing driving safety and experience. Furthermore, by calculating the optimal polarization unit angle, this application enables more effective reflection of P-polarized light, improving light utilization. By adjusting the angle of the polarization unit, the reflectivity of P-polarized light is maximized, thus reducing light loss. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0022] Figure 1 A flowchart of an angle calculation method provided in an embodiment of this application; Figure 2 This application provides a schematic diagram of the panoramic head-up display system structure and an optical path diagram. Figure 3 This is a schematic diagram of the display screen and polarization unit structure provided in an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures: 1. Windshield; 11. Reflector; 12. Vertical line; 2. Display screen; 3. Polarization unit. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0026] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0027] To address the technical problem in existing technologies where polarization unit 3 is directly rotated 90° and attached to the surface of display screen 2 to enhance P-polarized light reflection and suppress S-polarized light reflection, but the utilization rate of P-polarized light is low, this application provides an angle calculation method and a panoramic head-up display system. Through precise calculation, this application can obtain the rotation angle θ of polarization unit 3 that achieves the maximum reflectivity of P-polarized light. This ensures that P-polarized light can be efficiently reflected into the driver's line of sight, significantly improving the driver's visibility when wearing polarized sunglasses, thereby enhancing driving safety and driving experience.

[0028] Figures 1 to 3 An angle calculation method provided in this application embodiment is applied to a panoramic head-up display system. The panoramic head-up display system includes a windshield 1, a display screen 2, and a polarization unit 3. The plane of the polarization unit 3 is arranged parallel to the plane of the display screen 2. The method includes the following steps: Step S100: Calculate the normal vector of the display plane of display screen 2 based on three non-collinear points on the surface of display screen 2. Determine three non-collinear points on the surface of display screen 2. ,but In one embodiment, Then the vector = ,vector = The normal vector of the display plane of display screen 2 is calculated by the cross product of vectors. ( For example, in a specific embodiment, assume point The coordinates are respectively (1, 2, 3) (4, 5, 6) and (7, 8, 9), then the calculated vector =(3, 3, 3) and =(6, 6, 6). Since these two vectors are collinear, it is necessary to choose a non-collinear point, such as point... The coordinates are respectively (1, 2, 3) (4, 5, 6) and (7, 8, 10), the normal vector calculated at this time is n=(0, 0, 6), indicating that the display plane of display screen 2 has a certain tilt angle in the Z direction.

[0029] Calculating the normal vector of the display plane of display screen 2 using the above method enables precise description and positioning of the display plane, providing an accurate geometric basis for subsequent optical design and angle calculation of polarization unit 3. Specifically, this method ensures the accurate geometric relationship between the polarization direction of polarization unit 3 and the display plane of display screen 2, thereby maximizing the reflection efficiency of P-polarized light and improving light utilization and display effect. For example, in practical applications, precise calculation of the normal vector ensures more accurate angle adjustment of polarization unit 3, allowing drivers to clearly see the information on display screen 2 even when wearing polarized sunglasses, significantly improving driving safety and user experience.

[0030] For step S200, please refer to... Figure 2 According to the normal vector of the reflecting plane and the direction vector of the incident ray Calculate the direction vector of P-polarized light. .

[0031] Here, the reflecting plane is the plane containing the incident and reflected rays, used to calculate the direction vector of the P-polarized light. First, determine the normal vector of the reflecting plane. and the direction vector of the incident ray Assume the normal vector of the reflecting plane is... ( The direction vector of the incident ray is ( According to the definition of p-polarized light, the direction vector of p-polarized light... It should be parallel to both the incident plane and the reflecting plane, and the normal vector of the reflecting plane is... The direction vector of the incident ray Therefore, the direction vector of P-polarized light It can be calculated through the following steps: ; The direction vector of P-polarized light is calculated using the method described above. This method provides precise geometric parameters for the design of optical systems, ensuring that P-polarized light achieves optimal reflection efficiency during reflection. Specifically, this method effectively avoids light intensity loss caused by inaccurate polarization direction, improving the overall performance of the system. For example, in panoramic head-up display systems (P-HUDs), this is achieved by accurately calculating the direction vector of P-polarized light. This ensures that the polarization direction of polarization unit 3 is consistent with the direction of P-polarized light, thereby maximizing the reflectivity of P-polarized light and improving light utilization and display effect. Furthermore, this method can significantly improve driver visibility when wearing polarized sunglasses, enhancing the driving experience and improving driving safety.

[0032] Please see Figure 2 To facilitate the calculation of the normal vector of the reflecting plane, the coordinates of the intersection point between the main optical path and the windshield 1 are obtained. Coordinates of the center point of the eye ellipse The screen displays the coordinates of the center point of the area. ; Then the normal vector of the reflecting plane is: ; And the direction vector of the incident ray ; The direction vector of the P-polarized light mentioned above The coordinates of the intersection point between the main optical path and windshield 1 can then be used. Coordinates of the center point of the eye ellipse The screen displays the coordinates of the center point of the area. Confirm the three coordinates.

[0033] By acquiring the coordinates of the intersection point of the main optical path and the windshield 1, the coordinates of the center point of the eye ellipse, and the coordinates of the center point of the screen display area, and calculating the normal vector of the reflecting plane and the direction vector of the incident light, this technical solution can provide a precise geometric basis for the optical design of the panoramic head-up display system (P-HUD). This method ensures the accuracy and stability of the optical path, enabling P-polarized light to achieve efficient reflection on the windshield 1, thereby significantly improving the brightness and clarity of the display system. Simultaneously, through precise geometric parameter calculations, the layout of the optical system can be optimized, reducing optical path deviations caused by design errors, further improving system reliability and user experience. Furthermore, this method can effectively adapt to the geometric differences between the windshield 1 and the display screen 2 of different vehicle models, enhancing the system's versatility and adaptability, providing automakers with more flexible design solutions, and reducing development costs and time.

[0034] For step S300, please refer to... Figure 2 According to the definition of P-polarized light, a perpendicular line 12 is drawn in the reflecting plane, perpendicular to the incident ray. The projection of the perpendicular line 12 onto the display screen 2 is the projection line. The direction vector of the projection line is calculated. .

[0035] In this embodiment, according to the definition of P-polarized light, the polarization direction of P-polarized light is parallel to the incident plane and the reflecting plane (i.e., the plane formed by the incident light or reflected light and the normal). In this application, in order to obtain the polarization direction of P-polarized light, after obtaining the normal vector of the reflecting plane and the direction vector of the incident light, a unit vector perpendicular to the incident light vector is first drawn in the reflecting plane with the intersection of the main light path and the windshield 1 as the starting point, which is the vibration direction line of P-polarized light. Then, the perpendicular line 12 is orthogonally projected through the plane normal vector of the display screen 2 to obtain its two-dimensional projection line on the surface of the display screen 2. The direction vector of the projection line is obtained by subtracting the starting point coordinate from the end point coordinate of the projection line, which is the polarization direction of the polarization element above the display screen 2 of this application.

[0036] According to the formula for the projection of a vector onto a plane, the direction vector of the projection line can be determined. The calculation formula is as follows:

[0037] in, Let be the direction vector of the P-polarized light, which is the unit vector perpendicular to the incident ray vector mentioned above. This is the normal vector of the display plane of display screen 2.

[0038] By defining P-polarized light as parallel to the reflecting plane and perpendicular to the incident light, a two-step method of "drawing a perpendicular line 12 to the incident light and then projecting it onto the display screen 2" can accurately calculate the true projection direction of P-polarized light on the screen surface. This avoids the angular error caused by directly assuming a linear correspondence, ensuring that the transmission axis of the polarization unit 3 is strictly aligned with the vibration direction of the P-light. This increases the windshield's reflectivity to P-polarized light from less than 2% to over 15%. Specifically, even when wearing polarized sunglasses, the driver can still see a HUD virtual image with a brightness of ≥800 cd / m², meeting the requirements for use in strong daylight. At the same time, it reduces the visual angle difference caused by rotating the polarizer, achieving high brightness and high contrast display of the panoramic P-HUD across all vehicle models and at all eye elliptical positions.

[0039] Step S400: Obtain two points set vertically along the display area of ​​display screen 2, and calculate the reference vector. .

[0040] In one embodiment, two non-overlapping pixel-level coordinate points are arbitrarily selected along the longitudinal direction (typically corresponding to the front-rear direction of the vehicle body) within the display area of ​​the display screen 2, and denoted as points. With point Using the A→B vector as the vertical reference vector for the display area, the calculation formula is the reference vector. The reference vector in this application is only used to determine the polarization direction of polarization unit 3, so that the polarization direction of polarization unit 3 is consistent with the direction of the corresponding P-polarized light. The physical longitudinal direction of display screen 2 is directly locked by the "two-point longitudinal method", avoiding deviations of more than ±2° caused by relying on the nominal size of the mold or manual measurement, so that the calculation error of the subsequent polarizer rotation angle θ is controlled within ±0.1°. This ensures that the angle between the projection direction vector of P-polarized light and the transmission axis of polarizer is minimized, the reflected brightness is increased by more than 10%, and the difference in brightness between the left and right eyes caused by the misalignment of the reference direction is eliminated. This ensures that the driver can see a panoramic image with a uniform brightness of ≥600 cd / m² within a horizontal eye ellipse range of ±100 mm, thereby improving the mass production consistency and driving safety of P-HUD.

[0041] For step S500, please refer to [link / reference]. Figure 2 and Figure 3 According to the direction vector of the projection line and reference vector Calculate the rotation angle θ of polarization unit 3.

[0042] In one embodiment of this application, the obtained projection line direction vector is... Vertical reference vector of display screen 2 After normalization, according to the formula for calculating the angle between spatial vectors, we know that:

[0043] The formula for calculating the rotation angle θ of polarization unit 3 is as follows:

[0044] The required rotation angle θ of polarization unit 3 can be directly calculated. By using the one-step dot product method of "projection line-reference vector", the calculation accuracy of the rotation angle θ of polarization unit 3 can be improved to ±0.05°, which reduces 3-5 iterations compared with traditional trial installation calibration and shortens the development cycle. After the angle is accurate, the reflectivity of P-polarized light on the inner surface of the windshield is increased from less than 2% to 15%-18%, so that the HUD brightness is still higher than 600 cd / m² when wearing polarized sunglasses. At the same time, the lateral brightness gradient caused by the angle error is eliminated, ensuring that the brightness difference between the left and right eyes of the driver is less than 5% within ±100 mm of the eye ellipse, which significantly improves the mass production consistency and driving safety of the panoramic P-HUD.

[0045] Please see Figure 2This application also proposes a panoramic head-up display system, which adopts the above-mentioned angle calculation method, including a windshield 1, a display screen 2, and a polarization unit 3. The display screen 2 can emit light and project it onto the windshield 1. The windshield 1 is used to reflect the light to the human eye for imaging. The polarization unit 3 is located on the optical path from the display screen 2 to the windshield 1. The plane where the polarization unit 3 is located is parallel to the plane where the display screen 2 is located. The polarization direction of the polarization unit 3 is set at an angle θ with the direction from the bottom to the top of the display screen 2. The polarization unit 3 can enable the P-polarized light in the light emitted by the display screen 2 to be projected onto the windshield 1.

[0046] In this embodiment, the panoramic head-up display system (P-HUD) consists of a windshield 1, a display screen 2, and a polarization unit 3. The polarization unit 3 contains a linear polarization film, and its plane is 0.5 degrees parallel to the light-emitting surface of the display screen 2. The film has a parallel gap of less than mm and is attached to the outside of the display screen 2 by a vacuum adsorption fixture according to the calculated rotation angle θ. The long side of the film is rotated by an angle θ relative to the longitudinal direction (bottom → top) of the display screen 2. θ is calculated at once in the main optical path model of the whole vehicle according to the aforementioned "projection line-reference vector" algorithm, with a value range of 15°–30°. This cuts off the S-light component emitted by the LCD, and only P-polarized light is incident on the inner surface of the windshield. Since the rotation angle θ of the polarization unit 3 is locked and precisely attached at once by the whole vehicle-level optical path algorithm, the system can improve the P-polarized light reflection efficiency by 8-10 times without additional gain film or wedge glass. Compared with traditional S-HUD, the brightness loss when wearing polarized sunglasses is reduced from >80% to <15%, while maintaining an ultra-wide field of view and ultra-long virtual image distance without ghosting. This structure only adds a low-cost polarization film, does not change the windshield curvature, is compatible with existing HUD brackets, effectively reduces the cost per vehicle, meets automotive-grade reliability requirements, and realizes high brightness, low cost, and rapid mass production of panoramic P-HUD.

[0047] Please see Figure 2 The windshield 1 has a reflective part 11, which is located at one end of the windshield 1 near the display screen 2. The reflective part 11 is used to reflect the light projected by the display screen 2.

[0048] In one embodiment, the reflective portion 11 is processed by magnetron sputtering, nanoimprinting, or laser etching on a local area of ​​the inner surface of the windshield 1 to form a high-reflectivity optical functional layer, which can selectively enhance the reflectivity of P-polarized light while maintaining high transmittance of visible light. The reflective portion 11 is located at the end of the windshield 1 near the display screen 2, typically corresponding to the incident area of ​​the HUD light path. Its range is customized according to the eye ellipse and the position of the virtual image to ensure efficient reflection of light into the driver's field of vision. For example, a TiO2 / SiO2 multilayer dielectric film is used as the reflective portion 11, with a film thickness of 80–120 nm, increasing the reflectivity of P-polarized light to over 18% and controlling the reflectivity of S-polarized light to below 5%. Laser etching technology is used to form a micron-level periodic structure on the glass surface to achieve selective reflection enhancement while reducing haze. An ITO conductive film is first deposited in the reflective portion 11 area, followed by a multilayer reflective film, to achieve integrated defrosting and reflection functions, suitable for cold regions. By partially setting a reflector 11 on the windshield 1, the reflection efficiency of HUD light, especially P-polarized light, can be significantly improved without reducing the light transmittance of the entire vehicle's field of vision. This increases the brightness of the virtual image by 8–10 times, ensuring that the driver can still clearly see the high-brightness image when wearing polarized sunglasses. At the same time, it avoids the problems of high cost, large ghosting, and optical distortion caused by coating the entire glass surface, significantly reducing costs. Furthermore, the reflector 11 is firmly bonded to the glass body, meeting automotive-grade weather resistance requirements, greatly improving the display effect, system reliability, and mass production feasibility of the panoramic HUD.

[0049] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0050] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0051] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An angle calculation method applied to a panoramic head-up display system, the panoramic head-up display system comprising a windscreen (1), a display screen (2) and a polarizing unit (3), the plane in which the polarizing unit (3) is arranged being parallel to the plane in which the display screen (2) is arranged, characterized in that, Comprising the following steps: According to three points on the surface of the display screen (2) which are not collinear, a normal vector of the display plane of the display screen (2) is calculated ; According to the normal vector of the reflection plane and the direction vector of the incident light ray , the direction vector of the P-polarized light is calculated ; According to the definition of P polarized light, a perpendicular line to the incident light ray is made in the reflection plane, the projection of the perpendicular line in the display screen (2) is a projection line, the direction vector of the projection line is calculated ; Obtaining two points along the longitudinal direction of the display area of the display screen (2), calculating a reference vector ; from the direction vector of the projection line and the reference vector the rotation angle θ of the polarization unit (3) is calculated.

2. The angle calculation method according to claim 1, characterized in that, calculating a normal vector of the display plane of the display screen (2) according to the three points not in a straight line on the surface of the display screen (2) comprising determining three points not in a straight line on the surface of the display screen (2), then ; wherein, are the coordinates of three points not collinear with the surface of the display screen (2).

3. The angle calculation method of claim 1, wherein The normal vector of the reflection plane and the direction vector of the incident light ray comprises: acquiring the intersection coordinates of the main light path and the windshield glass (1) , eye ellipse center point coordinates , screen display area center point coordinates ; Compute the normal vector of the reflection plane: .

4. The angle calculation method according to claim 3, characterized by, a direction vector of the incident light ray .

5. The angle calculation method of claim 4, wherein said according to the normal vector of the reflection plane and the direction vector of the incident light ray , the P-polarized light direction vector comprises: According to the direction of the P-polarized light in the reflection plane and perpendicular to the vector , the P-polarized light direction vector .

6. The angle calculation method of claim 1, wherein According to the projection formula of a vector on a plane, the direction vector of the projection line is calculated as follows: wherein is a P-polarized light direction vector, is a normal vector of the display plane of the display screen (2).

7. The angle calculation method of claim 6, wherein, The two points are obtained along the longitudinal direction of the display area of the display screen (2), and a reference vector is calculated The two points are obtained along the longitudinal direction of the display area of the display screen (2), and a reference vector is calculated .

8. The angle calculation method of claim 7, wherein, The direction vector of the projection line and the reference vector The calculation of the rotation angle θ of the polarization unit (3) includes: According to the space vector included angle calculation formula, it can be known that: The calculation formula of the rotation angle θ of the polarization unit (3) is as follows: wherein is a direction vector of the projection line, is a reference vector on the display screen (2).

9. A panoramic head-up display system employing the angle calculation method according to any one of claims 1 to 8, characterized in that, Comprising: A windshield glass (1); A display screen (2) capable of emitting light rays to the windshield glass (1) for reflecting the light rays to the human eye for imaging; A polarization unit (3) located on the optical path of the display screen (2) projected to the windshield glass (1), the plane where the polarization unit (3) is located is parallel to the plane where the display screen (2) is located, the polarization direction of the polarization unit (3) is arranged at the rotation angle θ from the bottom to the top of the display screen (2), and the polarization unit (3) can project the P-polarized light in the light rays emitted by the display screen (2) to the windshield glass (1).

10. The panoramic heads-up display system of claim 9, wherein, The windshield glass (1) has a reflecting part (11) located at one end of the windshield glass (1) close to the display screen (2), and the reflecting part (11) is used for reflecting the light rays projected by the display screen (2).

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