Head-up display

Abstract

The utility model relates to a head-up display which is applied to windshield glass. The head-up display comprises an optical machine module, an optical waveguide and a windshield compensating mirror, the ray machine module is used for emitting image light containing image information; the coupling inlet of the optical waveguide is matched with the optical machine module, and the image light is accessed and transmitted to the coupling outlet of the optical waveguide so as to output the image light; the windshield compensating mirror is arranged between a coupling outlet of the optical waveguide and the windshield glass, the image light outputs corresponding emergent light to the windshield glass after passing through the windshield compensating mirror, and the emergent light enters a preset eye box area after being reflected by the windshield glass; wherein the focal plane of the windshield compensating mirror is located or basically located at the focal plane position of the windshield glass; and / or the focus of the windshield compensating mirror is located or basically located at the focus position of the windshield glass. By implementing the optical waveguide AR-HUD, the problem of image blurring of the optical waveguide AR-HUD can be effectively solved, and the image definition of the optical waveguide AR-HUD is improved.

Description

Technical Field

[0001] This utility model relates to the field of head-up display technology, and more specifically, to a head-up display. Background Technology

[0002] Head-Up Displays (HUDs) have evolved from military aviation technology into core interactive components for smart cars, undergoing three generations of technological leaps: C-HUD (Combiner HUD), W-HUD (Windshield HUD), and AR-HUD (Augmented Reality HUD). Currently, AR-HUDs are rapidly gaining popularity, becoming a key differentiator in smart cockpits. However, the large size of traditional reflective AR-HUDs limits their installation within vehicle space, hindering their widespread adoption. The industry has been seeking smaller AR-HUD solutions, leading to the emergence of small-volume waveguide AR-HUDs.

[0003] Optical waveguide AR-HUD technology achieves virtual-real fusion through optical reconstruction. Its core solutions can be divided into two main categories: geometric optical waveguides and diffractive optical waveguides. Due to the high imaging quality and excellent image performance such as no dispersion, geometric optical waveguides have become the preferred solution for optical waveguide AR-HUD.

[0004] However, because the windshield is a free-form surface with large differences in the horizontal and vertical radii of curvature, and the normal directions at different positions of the surface are inconsistent or even chaotic, the parallel light coupled out of the waveguide with good consistency will be reflected by the windshield and result in poor light consistency or even chaos. This will lead to problems such as image dizziness, static distortion, dynamic distortion, and even image blurring, which will affect driving safety. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a head-up display that addresses some of the technical deficiencies of the prior art.

[0006] The technical solution adopted by this utility model to solve its technical problem is: to construct a head-up display for use in a windshield; the head-up display includes: an optical engine module, an optical waveguide and a windshield compensation mirror;

[0007] The optomechanical module is used to emit image light containing image information;

[0008] The coupling inlet of the optical waveguide is configured in conjunction with the optomechanical module to receive the image light and transmit it to the coupling outlet of the optical waveguide to output the image light;

[0009] The windshield compensation mirror is disposed between the coupling outlet of the optical waveguide and the windshield glass. The image light is output as corresponding outgoing light after passing through the windshield compensation mirror and is reflected by the windshield glass into the preset eye box area.

[0010] Wherein, the focal plane of the windshield compensation mirror is located at or substantially located at the focal plane of the windshield; and / or, the focal point of the windshield compensation mirror is located at or substantially located at the focal point of the windshield.

[0011] Preferably, in one embodiment of the head-up display of the present invention, the absolute value of the focal length of the windshield compensation mirror is smaller than the absolute value of the focal length of the windshield glass.

[0012] Preferably, in one embodiment of the head-up display of this utility model, the windshield compensation mirror is a freeform surface lens with a negative focal length, a Fresnel lens, a liquid lens, a metasurface lens, or a holographic optical element.

[0013] The image light output from the coupling outlet of the optical waveguide is parallel light. The outgoing light after passing through the windshield compensation mirror is divergent light. The divergent light is reflected by the windshield glass to form parallel light and enters the preset eye box area.

[0014] Preferably, in one embodiment of the head-up display of the present invention, the freeform lens, Fresnel lens, liquid lens, metasurface lens or holographic optical element includes one or more optical elements; the focal length of the combination of the one or more optical elements is negative.

[0015] Preferably, in one embodiment of the head-up display of this utility model, the windshield compensation mirror is a freeform surface lens with a positive focal length, a Fresnel lens, a liquid lens, a metasurface lens, or a holographic optical element;

[0016] The image light output from the coupling outlet of the optical waveguide is parallel light. After passing through the windshield compensation mirror, the outgoing light forms a real image corresponding to the image information between the windshield compensation mirror and the windshield glass. The real image is reflected by the windshield glass to form parallel light, which then enters the preset eye box area.

[0017] Preferably, in one embodiment of the head-up display of the present invention, the freeform lens, Fresnel lens, liquid lens, metasurface lens or holographic optical element includes one or more optical elements; the focal length of the combination of the one or more optical elements is positive.

[0018] Preferably, in one embodiment of the head-up display of the present invention, each optical element comprises at least one curved surface or curved surface microstructure.

[0019] Preferably, in one embodiment of the head-up display of this utility model, the windshield compensation mirror and the optical waveguide are arranged parallel to each other, or arranged at a set angle in three-dimensional space.

[0020] Preferably, in one embodiment of the head-up display of this utility model, the surface profile parameters of the windshield compensation mirror match the surface profile parameters of the windshield glass; or

[0021] At least one surface of the windshield compensation mirror is a Zernike surface, a Chebyshev surface, or an extended polynomial surface.

[0022] Preferably, in one embodiment of the head-up display of this utility model, the optical waveguide is one of a one-dimensional optical waveguide and a two-dimensional optical waveguide; or

[0023] The optical waveguide is one of the following: geometric optical waveguide, tilted grating diffraction optical waveguide, and volume holographic grating diffraction optical waveguide.

[0024] Preferably, in one embodiment of the head-up display of this utility model, the spatial position and / or spatial angle between the windshield compensation mirror and the windshield glass is adjustable.

[0025] The head-up display that implements this utility model has the following beneficial effects: it can effectively solve the image blurring problem of optical waveguide AR-HUD and improve the image clarity of optical waveguide AR-HUD. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the structure of an embodiment of a head-up display according to the present invention;

[0028] Figure 2 This is a schematic diagram illustrating the working principle of an embodiment of a head-up display according to this utility model;

[0029] Figure 3 This is a schematic diagram illustrating the working principle of another embodiment of the head-up display of this utility model. Detailed Implementation

[0030] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0031] like Figure 1 The image shows an embodiment of a heads-up display according to the present invention. Figure 1In one embodiment of the present invention, the head-up display is mainly applied to a windshield 20. The head-up display includes an optical engine module 11, an optical waveguide 12, and a windshield compensation mirror 13. The optical engine module 11 is used to emit image light containing image information. The coupling inlet of the optical waveguide 12 is configured to cooperate with the optical engine module 11, receive the image light, and transmit it to the coupling outlet of the optical waveguide 12 to output the image light. The windshield compensation mirror 13 is disposed between the coupling outlet of the optical waveguide 12 and the windshield 20. After the image light passes through the windshield compensation mirror 13, it outputs corresponding outgoing light to the windshield 20 and enters a preset eye box area after being reflected by the windshield 20. The focal plane of the windshield compensation mirror 13 is located at or substantially located at the focal plane position of the windshield 20; and / or, the focal point of the windshield compensation mirror 13 is located at or substantially located at the focal point position of the windshield 20.

[0032] Specifically, in a head-up display (HUD), the optical-mechanical module 11 emits the required image light according to settings. For example, the optical-mechanical module 11 can receive image data from an external device and emit corresponding image light based on the image data. In a specific embodiment, the optical-mechanical module 11 can display an image based on the received image data through internal circuitry and project the image display using internal light-emitting circuitry. In this case, the light emitted by the optical-mechanical module 11 can be understood as image light containing the image display information (i.e., image information). The positions of the optical waveguide 12 and the optical-mechanical module 11 are configured such that the image light emitted by the optical-mechanical module 11 can enter the interior of the optical waveguide 12 through the coupling entrance of the optical waveguide 12 for transmission within the optical waveguide 12, and finally be output at the coupling exit of the optical waveguide 12.

[0033] The windshield compensation mirror 13 is coupled with the coupling outlet of the optical waveguide 12, allowing image light to enter the windshield compensation mirror 13 from one side after passing through the coupling outlet of the optical waveguide 12. The windshield compensation mirror 13 processes the image light, resulting in processed outgoing light on the other side. By strategically positioning the windshield compensation mirror 13 relative to the windshield 20, the outgoing light from the windshield compensation mirror 13 is reflected off the windshield 20, and the reflected light enters the preset eye-box area 30. When the driver's eyes are positioned within this preset eye-box area 30, they can see the image in the forward area 40, thus achieving head-up display. In one embodiment, the preset eye-box area 30 can be configured according to the driver's position, allowing the driver to easily see the necessary image information without affecting driving operations.

[0034] When setting the windshield compensation mirror, the focal plane of the windshield compensation mirror 13 can be set to be located at or approximately at the focal plane of the windshield glass 20. This ensures that the light rays from the coupling outlet of the optical waveguide 12 coincide as much as possible with the imaging position of the windshield compensation mirror 13 and the imaging position of the windshield glass 20. Consequently, the parallel light output from the coupling outlet of the optical waveguide 12 can still enter the preset eye box area 30 in a parallel manner after passing through the windshield compensation mirror 13 and the windshield glass 20. This ensures that the image seen by the human eye within the preset eye box area 30 remains clear, and that the image is not blurred due to excessive astigmatism caused by the inconsistent curvature radii of the windshield glass 20 at the meridional and sagittal points, which would result in non-parallel light entering the human eye after reflection from the windshield glass 20.

[0035] In one embodiment, the focal point of the windshield compensation mirror 13 can be set to be located at or substantially at the focal point of the windshield glass 20, so that the light rays from the coupling outlet of the optical waveguide 12 coincide as much as possible with the imaging position of the windshield compensation mirror 13 and the imaging position of the windshield glass 20. This allows the parallel light output from the coupling outlet of the optical waveguide 12 to still enter the preset eye box area 30 in a parallel manner after passing through the windshield compensation mirror and the windshield glass 20. This ensures that the image seen by the human eye in the preset eye box area 30 remains clear, and the image will not be blurred due to excessive astigmatism caused by the inconsistent curvature radii of the windshield glass 20 at the meridional and sagittal points, which would cause the light rays to enter the human eye in a non-parallel manner after reflection by the windshield glass 20.

[0036] In one embodiment, the focal plane of the windshield compensation mirror 13 can be simultaneously located at or substantially at the focal plane of the windshield 20; and the focal point of the windshield compensation mirror 13 can be located at or substantially at the focal point of the windshield 20. This maximizes the possibility of ensuring that the reflected light from the windshield 20 is parallel light, thereby improving the clarity of the image seen by the human eye.

[0037] In one embodiment, the absolute focal length of the windshield compensation mirror 13 is less than the absolute focal length of the windshield glass 20. That is, when selecting the windshield compensation mirror 13, it is necessary to set the absolute focal length of the windshield compensation mirror 13 to be less than the absolute focal length of the windshield glass 20. This process ensures that the image seen by the human eye is a magnified image, thus guaranteeing the display effect.

[0038] like Figure 2As shown, in one embodiment, the windshield compensation mirror 13 is a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a negative focal length. The image light output from the coupling outlet of the optical waveguide 12 is parallel light, and the outgoing light output after passing through the windshield compensation mirror 13 is divergent light. The divergent light is reflected by the windshield glass 20 to form parallel light, which enters the preset eye box area 30. Specifically, when the windshield compensation mirror 13 uses optical components such as a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a negative focal length, the function of the windshield compensation mirror 13 can be equivalent to a negative lens. Since a negative lens can diverge parallel incident light rays, the virtual focal point A of the negative lens is located on the backward extension line of the incident light rays. Because the focal point of the windshield glass 20 coincides with the focal point of the negative lens, when the divergent light beam passing through the negative lens continues to propagate forward, it is equivalent to the light emitted from the focal point of the windshield glass 20, which will form parallel light after being reflected by the windshield glass 20. It is important to further emphasize that, because the windshield 20 is a freeform surface with significant differences in radius at each point, the focal point of parallel light after passing through the windshield 20 is not an ideal image point but a circle of confusion. The windshield compensation mirror 13 compensates for these differences at each point on the surface, effectively transforming the circle of confusion into an ideal image point, thus achieving a match between the surface shape of the windshield compensation mirror 13 and the surface shape of the windshield 20. Furthermore, the light rays from the coupling exit of the optical waveguide 12 enter the windshield compensation mirror 13 from one side, forming a virtual image on the same side. The position of this virtual image almost coincides with the imaging position of the windshield 20. Therefore, the diverging light from the other side of the windshield compensation mirror 13 enters the windshield 20, is reflected by the windshield 20, and forms parallel light that enters the preset eye box region 30. At this time, when the human eye is located in the preset eye box region 30, the image located in the forward region 40 can be seen.

[0039] Optionally, the freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element includes one or more optical elements; the focal length of the combination of one or more optical elements is negative. That is, the optical element, such as the freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element, can be a single optical element or a combination of multiple optical elements. When the optical element contains only a single optical element, the focal length of that optical element is negative. When the optical element contains multiple optical elements, the focal length of the combination of those multiple optical elements is negative.

[0040] Building upon the above, each optical element comprises at least one curved surface or curved surface microstructure. Specifically, in one embodiment, the upper surface of the optical element is a freeform surface and the lower surface is a plane; or the upper surface is a freeform surface and the lower surface is a sphere; or the upper surface is a freeform surface and the lower surface is an aspherical surface. Alternatively, the lower surface can be a freeform surface and the upper surface a plane; or the lower surface can be a freeform surface and the upper surface a sphere; or the lower surface can be a freeform surface and the upper surface an aspherical surface. That is, combinations can be made as needed.

[0041] It is understandable that when the absolute value of the focal length of an optical component with a negative focal length, such as a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element, is less than the absolute value of the focal length of the windshield 20, it means that the windshield compensating mirror 13 with a negative focal length has a greater ability to diverge light than the windshield 20 has to converge light. Since the windshield compensating mirror 13 must be installed under the dashboard of the vehicle, and the focal point of the windshield 20 coincides with the focal point of the windshield compensating mirror 13, it is necessary to set the focal length of the windshield compensating mirror 13 to be less than the focal length of the windshield 20.

[0042] In one embodiment, such as Figure 3As shown, the windshield compensation mirror 13 is a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a positive focal length. The image light output from the coupling outlet of the optical waveguide 12 is parallel light. After passing through the windshield compensation mirror 13, the outgoing light forms a real image corresponding to the image information between the windshield compensation mirror and the windshield glass 20. The real image is reflected by the windshield glass 20 to form parallel light, which enters the preset eye box area 30. Specifically, when the windshield compensation mirror 13 uses optical components such as a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a positive focal length, the function of the windshield compensation mirror 13 can be equivalent to a positive lens. This positive lens can converge parallel incident light rays, and its focal point B is located in the transmission direction of the incident light rays. Because the focal point of the windshield glass 20 coincides with the focal point of the positive lens, when the diverging beam of light passing through the positive lens continues to propagate forward, it is equivalent to the light emitted from the focal point of the windshield glass 20 being reflected by the windshield glass 20 to form parallel light output. It is important to further emphasize that, because the windshield 20 is a freeform surface with significant differences in radius at each point, the focal point of parallel light after passing through the windshield 20 is not an ideal image point but a circle of confusion. The windshield compensation mirror 13 compensates for these differences at each point on the surface, effectively transforming the circle of confusion into an ideal image point, thus achieving a match between the surface shape of the windshield compensation mirror 13 and the surface shape of the windshield 20. Furthermore, the light rays from the coupling exit of the optical waveguide 12, after entering the windshield compensation mirror 13 from one side, form a real image on the other side. The position of this real image almost coincides with the imaging position of the windshield 20. Therefore, the converging light from the other side of the windshield compensation mirror 13, after entering the windshield 20, is reflected by the windshield 20 to form parallel light that enters the preset eye box region 30. At this time, when the human eye is located in the preset eye box region 30, the image located in the forward region 40 can be seen.

[0043] Optionally, a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element includes one or more optical elements; the focal length of the combination of one or more optical elements is positive. That is, the optical element, such as a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element, can be a single optical element or a combination of multiple optical elements. When the optical element contains only a single optical element, the focal length of that single optical element is positive. When the optical element contains multiple optical elements, the focal length of the combination of those multiple optical elements is positive.

[0044] Building upon the above, each optical element comprises at least one curved surface or curved surface microstructure. Specifically, in one embodiment, the upper surface of the optical element is a freeform surface and the lower surface is a plane; or the upper surface is a freeform surface and the lower surface is a sphere; or the upper surface is a freeform surface and the lower surface is an aspherical surface. Alternatively, the lower surface can be a freeform surface and the upper surface a plane; or the lower surface can be a freeform surface and the upper surface a sphere; or the lower surface can be a freeform surface and the upper surface an aspherical surface. That is, combinations can be made as needed.

[0045] In one embodiment, the windshield compensation mirror 13 and the optical waveguide 12 are arranged parallel to each other, or at a set angle in three-dimensional space. Specifically, the windshield compensation mirror 13 and the optical waveguide 12 can be arranged parallel to each other so that the outgoing light from the optical waveguide 12 can enter the windshield compensation mirror 13 perpendicularly. Alternatively, the windshield compensation mirror 13 and the optical waveguide 12 can be arranged at a relative angle in three-dimensional space to ensure that the light passing through the windshield compensation mirror 13 can enter the windshield glass 20 in a suitable area to obtain parallel outgoing light in the preset eye box area 30.

[0046] In one embodiment, the spatial position and / or spatial angle between the windshield compensating mirror 13 and the windshield 20 are adjustable. Alternatively, at least one of the spatial position and spatial angle between the windshield compensating mirror 13 and the windshield 20 can be adjusted. This allows for adjustments to the relative position or angle between the windshield compensating mirror 13 and the windshield 20 when slight changes occur on the surface of the windshield 20, ensuring a clear image is still visible in the preset eye box area 30. It also allows the head-up display to be easily and quickly matched with different types of windshields 20 during installation, accommodating more vehicle models, without the windshield compensating mirror 13 being unable to be positioned correctly due to installation location limitations.

[0047] In one embodiment, the surface profile parameters of the windshield compensation mirror 13 are matched with those of the windshield 20. Specifically, to compensate for the aberration caused by the windshield 20, the surface profile parameters of the windshield compensation mirror 13 need to be matched with those of the windshield 20. For example, when the windshield compensation mirror 13 is a freeform lens, the optical parameters such as the radius of curvature, thickness, conic coefficient, and higher-order coefficients of the freeform lens are adjusted according to the surface profile of the windshield 20 to achieve surface profile compensation of the windshield 20, ultimately achieving parallel light reflection from the windshield 20. For other types of windshield compensation mirrors 13, matching can also be performed based on a similar parameter matching method. In one embodiment, at least one surface profile of the windshield compensation mirror 13 is a Zernike surface, a Chebyshev surface, or an extended polynomial surface.

[0048] In one embodiment, the optical waveguide 12 can be configured as either a one-dimensional or two-dimensional optical waveguide. The one-dimensional waveguide expands the pupil only in a single direction (one-dimensional) (typically horizontal or vertical). After light enters the waveguide through the input coupler, it propagates in one direction and is uniformly expanded through the output coupler. The two-dimensional waveguide expands the pupil in two directions (horizontal + vertical), achieving a larger eye movement range through two-stage expansion, thus allowing for a larger setting range for the preset eye box region 30.

[0049] In one embodiment, the optical waveguide 12 is one of a geometric waveguide, a slanted angle grating diffractive waveguide, and a volume holographic grating diffractive waveguide. The geometric waveguide, based on traditional geometric optics (reflection / refraction), transmits light through total internal reflection within the waveguide via an array of mirrors or prisms, ultimately coupling it out. The slanted angle grating (SAG) diffractive waveguide utilizes the slanted structure of a surface relief grating (SRG) to achieve diffraction coupling of light, allowing for optimized design of the grating period and tilt angle. The volume holographic grating diffractive waveguide is based on holographic interference recording to form a volume grating within a photosensitive material (such as a photopolymer), selectively coupling light through Bragg diffraction.

[0050] Compared to the blurry images of current optical waveguide AR-HUD solutions, the above embodiments can achieve clear imaging images of optical waveguide AR-HUD.

[0051] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A heads-up display, characterized in that, Applied to windshields; the head-up display includes: an optomechanical module, an optical waveguide, and a windshield compensation mirror; The optomechanical module is used to emit image light containing image information; The coupling inlet of the optical waveguide is configured in conjunction with the optomechanical module to receive the image light and transmit it to the coupling outlet of the optical waveguide to output the image light; The windshield compensation mirror is disposed between the coupling outlet of the optical waveguide and the windshield glass. The image light is output as corresponding outgoing light after passing through the windshield compensation mirror and is reflected by the windshield glass into the preset eye box area. Wherein, the focal plane of the windshield compensation mirror is located at or substantially located at the focal plane of the windshield; and / or, the focal point of the windshield compensation mirror is located at or substantially located at the focal point of the windshield.

2. The head-up display according to claim 1, characterized in that, The absolute value of the focal length of the windshield compensation mirror is smaller than the absolute value of the focal length of the windshield glass.

3. The head-up display according to claim 1, characterized in that, The windshield compensation mirror is a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a negative focal length; The image light output from the coupling outlet of the optical waveguide is parallel light. The outgoing light after passing through the windshield compensation mirror is divergent light. The divergent light is reflected by the windshield glass to form parallel light and enters the preset eye box area.

4. The head-up display according to claim 3, characterized in that, The freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element includes one or more optical elements; the focal length of the combination of the one or more optical elements is negative.

5. The head-up display according to claim 1, characterized in that, The windshield compensation mirror is a freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element with a positive focal length; The image light output from the coupling outlet of the optical waveguide is parallel light. After passing through the windshield compensation mirror, the outgoing light forms a real image corresponding to the image information between the windshield compensation mirror and the windshield glass. The real image is reflected by the windshield glass to form parallel light, which then enters the preset eye box area.

6. The head-up display according to claim 5, characterized in that, The freeform lens, Fresnel lens, liquid lens, metasurface lens, or holographic optical element includes one or more optical elements; the focal length of the combination of the one or more optical elements is positive.

7. The head-up display according to claim 3 or 6, characterized in that, Each of the optical elements comprises at least one curved surface or curved surface microstructure.

8. The head-up display according to any one of claims 1-6, characterized in that, The windshield compensation mirror is arranged parallel to the optical waveguide, or at a set angle in three-dimensional space.

9. The head-up display according to any one of claims 1-6, characterized in that, The surface profile parameters of the windshield compensation mirror match the surface profile parameters of the windshield glass; or At least one surface of the windshield compensation mirror is a Zernike surface, a Chebyshev surface, or an extended polynomial surface.

10. The head-up display according to any one of claims 1-6, characterized in that, The optical waveguide is either a one-dimensional optical waveguide or a two-dimensional optical waveguide; or The optical waveguide is one of the following: geometric optical waveguide, tilted grating diffraction optical waveguide, and volume holographic grating diffraction optical waveguide.

11. The head-up display according to any one of claims 1-6, characterized in that, The spatial position and / or spatial angle between the windshield compensating mirror and the windshield glass can be adjusted.

Images