Head-up display device and vehicle
By designing optical components and image generation units, the virtual image is made to fit or be parallel to the road surface, solving the problem of poor integration between the virtual image and the real environment in existing head-up display devices, thus improving driving safety and experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 欧摩威汽车电子(芜湖)有限公司
- Filing Date
- 2023-04-19
- Publication Date
- 2026-05-12
AI Technical Summary
The virtual image of existing head-up displays cannot blend with the real environment, causing drivers to frequently adjust their focus when observing the virtual image, which affects driving safety and experience.
By designing optical components and image generation units, the image plane of the virtual image is made to be basically aligned with the road surface. The projection distance of the virtual image is extended by optical elements such as aspherical mirrors and wedge mirrors. Astigmatism correction is performed in combination with the curvature characteristics of the windshield to ensure that the virtual image is parallel to or aligned with the ground.
It enhances the augmented reality experience, reduces driver eye fatigue, and improves driving safety and comfort.
Smart Images
Figure CN116381947B_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to the field of optical display technology, and more particularly to a head-up display device and a vehicle. Background Technology
[0002] Vehicles and other means of transportation have become an indispensable part of modern life, but driving safety has also become a major threat to people's lives. Drivers typically ensure reliable driving by closely monitoring the driving information on the vehicle's dashboard. However, due to the limited size of vehicles, dashboards are usually located below the control panel. This forces drivers to look down at the dashboard frequently, which can easily lead to distraction and cause traffic accidents.
[0003] In industries such as automotive, head-up displays (HUDs) are commonly used to insert content into the driver's field of vision, allowing the driver to observe that content directly in their line of sight. This can, to some extent, reduce the time a driver's eyes are off the road due to frequent head-down movements. Summary of the Invention
[0004] This invention provides a head-up display device and a vehicle.
[0005] In one aspect of this disclosure, a head-up display (HUD) is provided. The HUD includes an image generating unit and an optical component, wherein: the image generating unit is configured to generate and project light carrying first image information of a first source image to be projected toward the optical component; the optical component is configured to redirect the light from the image generating unit onto the windshield of a vehicle, such that the windshield reflects the light from the optical component to form a first virtual image of the first source image in front of the vehicle, wherein the first virtual image has a near end closer to the vehicle and a far end farther from the vehicle; at least one of the optical component and the image generating unit is further configured such that the light path between the image generating unit and the windshield for the first virtual image gradually lengthens from the ray corresponding to the near end to the ray corresponding to the far end.
[0006] In some embodiments of this disclosure, the optical path between the image generation unit and the windshield gradually lengthens in such a way that the image plane in which the first virtual image is located is substantially in contact with the road surface.
[0007] In some embodiments of this disclosure, the image generating unit has a light-emitting surface facing at least a portion of the optical component, and the light-emitting surface of the image generating unit is oriented such that the light path between the image generating unit and the windshield for the first virtual image gradually lengthens from the ray corresponding to the near end to the ray corresponding to the far end.
[0008] In some embodiments of this disclosure, the image generation unit includes: a light source; a display unit located in an optical path between the light source and the optical component, wherein the light-emitting surface of the display unit is the light-emitting surface of the image generation unit; and a light guide located in an optical path between the light source and the display unit, the light guide being configured to guide light from the light source to the display unit, wherein the light guide has a first surface facing the display unit and a second surface opposite to the first surface, wherein the first surface is inclined relative to the second surface such that the distance of the first surface from the second surface on the side from which the light source corresponding to the distal end originates is less than the distance of the first surface from the second surface on the side from which the light source corresponding to the proximal end originates, and the light-emitting surface of the display unit is oriented parallel to the first surface.
[0009] In some embodiments of this disclosure, the angle of inclination of the first surface relative to the second surface is not less than 25 degrees.
[0010] In some embodiments of this disclosure, the optical component includes a planar mirror and a freeform optical element, wherein the planar mirror is configured to redirect light from the image generation unit toward the freeform optical element; and the freeform optical element is configured to redirect light from the planar mirror toward the windshield.
[0011] In some embodiments of this disclosure, the freeform optical element is an aspherical mirror with non-uniform curvature, and the freeform optical element is further configured to pre-correct astigmatism caused by the windshield.
[0012] In some embodiments of this disclosure, the first source image is an inverted image, and wherein the free-form optical element is further arranged such that the first virtual image is inverted relative to the first source image, such that light rays corresponding to the far end originate from the bottom of the first source image, and light rays corresponding to the near end originate from the top of the first source image.
[0013] In some embodiments of this disclosure, the optical component includes: a plane mirror, a first free-form optical element, and a second free-form optical element, wherein the plane mirror is configured to redirect light from the image generation unit toward the first free-form optical element; the first free-form optical element is configured to redirect light from the plane mirror toward the second free-form optical element; and the second free-form optical element is configured to redirect light from the first free-form optical element toward the windshield.
[0014] In some embodiments of this disclosure, the first free-form optical element and the second free-form optical element are aspherical mirrors with non-uniform curvature.
[0015] In some embodiments of this disclosure, the curvature of at least one of the first free-form optical element and the second free-form optical element gradually increases from the position where the light ray corresponding to the near end is incident on the corresponding free-form optical element to the position where the light ray corresponding to the far end is incident on the corresponding free-form optical element.
[0016] In some embodiments of this disclosure, the curvature of the first freeform optical element gradually increases from the position where the light ray corresponding to the near end is incident on the first freeform optical element to the position where the light ray corresponding to the far end is incident on the first freeform optical element, and the second freeform optical element is further configured to pre-correct astigmatism caused by the windshield.
[0017] In some embodiments of this disclosure, the first source image is an inverted image, and wherein the second free-form optical element is further arranged such that the first virtual image is inverted relative to the first source image, such that light rays corresponding to the far end originate from the bottom of the first source image, and light rays corresponding to the near end originate from the top of the first source image.
[0018] In some embodiments of this disclosure, the optical component further includes a wedge mirror disposed on one side of the light-emitting surface of the image generating unit, the wedge mirror being arranged such that light rays from the image generating unit corresponding to the distal end are transmitted through a thicker portion of the wedge mirror, and light rays from the image generating unit corresponding to the proximal end are transmitted through a thinner portion of the wedge mirror.
[0019] In some embodiments of this disclosure, at least a portion of the surface of the wedge mirror away from the image generation unit is an outwardly projecting curved surface.
[0020] In some embodiments of this disclosure, the curvature of the surface is designed to gradually increase from the position where light rays from the image generation unit corresponding to the near end exit the wedge mirror to the position where light rays from the image generation unit corresponding to the far end exit the wedge mirror.
[0021] In some embodiments of this disclosure, the image generation unit is further configured to generate light carrying second image information of a second source image to be projected, and the optical component is further configured to redirect the light carrying the second image information from the image generation unit to the windshield, so that the windshield can reflect the light from the optical component to form a second virtual image of the second source image in front of the vehicle, wherein the distance between the second virtual image and the vehicle is less than the distance between the first virtual image and the vehicle.
[0022] In some embodiments of this disclosure, the image plane of the second virtual image is substantially perpendicular to the road surface.
[0023] In another aspect of this disclosure, a vehicle is also provided. The vehicle includes a windshield and any of the head-up display devices described in embodiments of this disclosure relating to head-up display devices, the windshield being configured to form a first virtual image of the first source image in front of the vehicle by reflecting light from the head-up display device carrying first image information of a first source image to be projected.
[0024] Further aspects and scope of adaptation become apparent from the description provided herein. It should be understood that various aspects of this application may be implemented individually or in combination with one or more other aspects. It should also be understood that the descriptions and specific embodiments herein are for illustrative purposes only and are not intended to limit the scope of this application. Attached Figure Description
[0025] The accompanying drawings described herein are for illustrative purposes only, and do not represent all possible implementations, and are not intended to limit the scope of this application, wherein:
[0026] Figure 1 The diagram schematically illustrates a head-up display device and its associated optical path in the related art;
[0027] Figure 2 A head-up display device and its associated optical path are schematically illustrated in one or more embodiments of this disclosure;
[0028] Figure 3 A schematic diagram showing astigmatism introduced by the windshield is shown;
[0029] Figure 4 A cross-sectional view of an exemplary image generation unit in one or more embodiments of this disclosure is shown schematically;
[0030] Figure 5 Another head-up display device and its associated optical path are schematically illustrated in one or more embodiments of this disclosure;
[0031] Figure 6 This schematically illustrates yet another head-up display device and its associated optical path in one or more embodiments of this disclosure;
[0032] Figure 7 A wedge-shaped mirror with a curved surface is schematically illustrated in one or more embodiments of this disclosure;
[0033] Figure 8 This schematically illustrates yet another head-up display device and its associated optical path in one or more embodiments of this disclosure;
[0034] Figure 9 This schematically illustrates yet another head-up display device and associated optical path in one or more embodiments of this disclosure;
[0035] Figure 10 This schematically illustrates yet another head-up display device and associated optical path in one or more embodiments of this disclosure;
[0036] Figure 11 The diagram schematically illustrates yet another head-up display device and its associated optical path according to one or more embodiments of this disclosure; and
[0037] Figure 12 A block diagram of a vehicle according to one or more embodiments of this disclosure is shown schematically.
[0038] Throughout the various views of these accompanying drawings, corresponding reference numerals indicate the respective parts or features. Detailed Implementation
[0039] Various embodiments will now be described in detail with reference to the accompanying drawings, which are provided as exemplary examples of the invention to enable those skilled in the art to implement it. It is important to note that the following drawings and examples are not intended to limit the scope of the invention. Where specific elements of the invention can be partially or wholly implemented using known components, only those portions of such known components necessary for understanding the invention will be described, and detailed descriptions of other portions of such known components will be omitted so as not to obscure the invention. Furthermore, the various embodiments include, by way of illustration, present and future known equivalents of the components involved herein.
[0040] In the following description, the accompanying drawings are not necessarily drawn to scale. In particular, the relative positions and dimensions between the various components of the head-up display device, the virtual image, the vehicle, and other elements involved therein may be exaggerated. For purposes of clarity and brevity or for the purpose of providing information, certain features may be shown in a generalized or schematic form. Furthermore, although several different embodiments of the head-up display device are discussed in detail below, it should be understood that many inventive concepts as described herein can be implemented in a variety of environments. The embodiments discussed herein are merely representative and do not limit the scope of the invention.
[0041] As used herein, the terms “have,” “include,” and “contain,” as well as their grammatical variations, are used in a non-exclusive manner. Thus, the statement “A has B” and the expressions “A includes B” or “A contains B” can refer to the fact that A contains one or more other components and / or elements besides B, and the situation where no other components, elements, or elements are present in A besides B.
[0042] In head-up display (HUD) technology, HUDs project important driving information onto the driver's line of sight by reflecting an image through the windshield (also known as the windshield) or a specially designed transparent imaging window. This eliminates the need for the driver to look down at the instrument panel while driving, thus avoiding distraction and ensuring driving safety.
[0043] Figure 1 The diagram schematically illustrates a head-up display device and its associated optical path in the related art. For example... Figure 1 As shown, a head-up display (HUD) in related technologies may include an image generator 7, a flat mirror 1, and a curved mirror 6. The image generator 7 projects light carrying image information onto the flat mirror 1. This light is reflected sequentially by the flat mirror 1 and the curved mirror 6 before entering the windshield 3 of the vehicle. The windshield 3 reflects the light carrying image information to form an image (generally a virtual image) at a certain distance in front of the vehicle. Information such as vehicle speed, vehicle condition, fuel level, and navigation can be displayed on the image. The driver can see this image within a suitable viewing area 2.
[0044] like Figure 1 As shown, head-up displays in related technologies insert images essentially vertically into the driver's line of sight. This type of head-up display, which forms a vertical image, cannot blend well with the real environment. Especially when augmented reality (AR) navigation is required, it is often desirable for navigation information to be as close to the ground as possible to enhance the AR experience. However, the vertical images in related technologies cannot achieve this ground-hugging effect, thus significantly impacting the driving experience.
[0045] In addition, vertical images are usually located within or near the user's lower field of view, and the focusing distance of the virtual image (when the projection distance is close) or part of the virtual image (when the projection distance is far) differs from the distance of the real object outside the vehicle within the same field of view. This causes the driver's eyes to repeatedly adjust the focus to observe the real object or the virtual image, resulting in eye fatigue and affecting driving safety.
[0046] In at least some embodiments of this disclosure, a head-up display device is provided that can project a virtual image displayed substantially horizontally onto the vicinity of the ground, so that the image projected by the head-up display device can be better integrated with the ground, thereby improving the augmented reality experience and improving driving safety.
[0047] As used herein, the term “substantially vertical” refers to a condition of vertical orientation, with tolerances of, for example, ±30° or less, preferably ±20° or less, and more preferably ±10° or less. Similarly, the term “substantially horizontal” refers to a condition of horizontal orientation, with tolerances of, for example, ±30° or less, preferably ±20° or less, and more preferably ±10° or less.
[0048] The head-up display device provided herein will be described in detail below with reference to the accompanying drawings.
[0049] Since the head-up display devices described in the embodiments herein are typically used in vehicles, the embodiments and accompanying drawings are described in conjunction with a vehicle (especially the windshield) to facilitate the description of the structure and operating principle of the head-up display device. In practice, the head-up display device can be a separate device independent of the vehicle. However, it should be understood that the head-up display device can also be integrated into the vehicle as a sub-component.
[0050] Figure 2 A head-up display device 20 and its associated optical path are schematically illustrated in one or more embodiments of this disclosure. For example... Figure 2 As shown, the head-up display device 20 includes an image generation unit 11 and an optical component 12. The image generation unit 11 is configured to generate and project light carrying first image information of a first source image to be projected toward the optical component 12; the optical component 12 is configured to redirect the light from the image generation unit 11 onto the windshield 13 of the vehicle, so that the windshield 13 can reflect the light from the optical component 12 to form a first virtual image 14 of the first source image in front of the vehicle.
[0051] Continue to refer to Figure 2The first virtual image 14 has a near end 141 closer to the vehicle and a far end 142 farther from the vehicle. The optical component 12 can be further configured such that the light path between the image generating unit 11 and the windshield 13 for the first virtual image 14 gradually increases in length from the ray 4 corresponding to the near end 141 to the ray 5 corresponding to the far end 142. That is, the optical path length of the ray 4 corresponding to the near end 141 of the first virtual image 14 between the image generating unit 11 and the windshield 13 is shorter than the optical path length of the ray 5 corresponding to the far end 142, and the optical path length of the ray between the ray 4 and the ray 5 gradually increases from the ray 4 to the ray 5 between the image generating unit 11 and the windshield 13.
[0052] In some embodiments of this disclosure, the first source image is ultimately imaged via the windshield 13. The length of the optical path between the windshield 13 and the image generation unit 11 is equivalent to the object distance, while the length of the optical path between the windshield and the first virtual image is equivalent to the image distance. According to the principle of optical systems based on reflection to form virtual images, the longer the object distance, the longer the image distance.
[0053] Therefore, according to some embodiments of this disclosure, the optical path between the windshield 13 and the image generation unit 11 is configured to gradually increase in length from the light ray 4 corresponding to the near end 141 to the light ray 5 corresponding to the far end 142, which can make the image distance of the far end 142 of the first virtual image 14 greater than the image distance of the near end 141. Therefore, the first virtual image 14 can be tilted relative to the road surface.
[0054] By reasonably setting the optical parameters and / or spatial layout of the optical component 12, the first virtual image 14 can be tilted to a large extent, or even the image plane on which the first virtual image 14 is located can be basically in contact with the road surface. That is, the optical path between the image generation unit 11 and the windshield 13 gradually lengthens from the ray 4 corresponding to the near end 141 of the first virtual image 14 to the ray 5 corresponding to the far end 142, in a way that makes the image plane on which the first virtual image 14 is located basically in contact with the road surface.
[0055] The image plane of the first virtual image 14 is basically aligned with the road surface, allowing information displayed on the image (especially navigation-related information) to be projected onto the road surface, which enhances the augmented reality experience. Furthermore, projecting the image onto the road surface makes it less likely to obstruct the driver's view, thus improving driving safety.
[0056] refer to Figure 2In some embodiments of this disclosure, the optical component 12 may include a plane mirror 123, a first free-form optical element 121, and a second free-form optical element 122. The plane mirror 123 may be configured to redirect light from the image generation unit 11 toward the first free-form optical element 121; the first free-form optical element 121 may be configured to redirect light from the plane mirror 123 toward the second free-form optical element 122; and the second free-form optical element 122 may be configured to redirect light from the first free-form optical element 124 toward the windshield 13.
[0057] In one or more embodiments of this disclosure, the plane mirror 123 can be used to fold the optical path between the image generation unit 11 and the windshield 13 in order to extend the object distance between the image generation unit 11 and the windshield 13, thereby projecting the first virtual image to a place farther away from the vehicle, and at the same time reducing the space occupied by the optical path between the image generation unit 11 and the windshield 13.
[0058] In one or more embodiments of this disclosure, the first free-form optical element 121 and the second free-form optical element 122 may be aspherical mirrors with non-uniform curvature.
[0059] In one or more embodiments of this disclosure, the curvature of one or both of the first free-form optical element 121 and the second free-form optical element 122 may gradually increase from the incident position of the ray 4 corresponding to the near end 141 on the corresponding free-form optical element to the incident position of the ray 5 corresponding to the far end 142 on the corresponding free-form optical element.
[0060] Specifically, in Figure 2 In the illustrated embodiment, the ray 5 corresponding to the far end 142 of the first virtual image 14 is incident near the bottom end of the first free-form optical element 121, and the ray 4 corresponding to the near end 141 of the first virtual image 14 is incident near the top end of the first free-form optical element 121. Therefore, the curvature of the first free-form optical element 121 can be designed to gradually decrease from the bottom end to the top end, so that the ray reflected by the bottom end of the first free-form optical element 121 is projected to a position farther away from the vehicle, while the ray reflected by the top end of the first free-form optical element 121 is projected to a position closer to the vehicle.
[0061] Similarly, the ray 5 corresponding to the far end 142 of the first virtual image 14 is incident near the bottom end of the second free-form optical element 122, and the ray 4 corresponding to the near end 141 of the first virtual image 14 is incident near the top end of the second free-form optical element 122. Therefore, the curvature of the second free-form optical element 122 can be designed to gradually decrease from the bottom end to the top end, so that the ray reflected by the bottom end of the second free-form optical element 122 is projected to a position farther away from the vehicle, while the ray reflected by the top end of the second free-form optical element 122 is projected to a position closer to the vehicle.
[0062] In the embodiments of this disclosure, the light carrying image information emitted from the image generation unit 11 is reflected multiple times by the optical elements in the optical assembly 12, and finally the windshield 13 projects the image onto the front of the vehicle near the road surface.
[0063] When the windshield 13 is a flat reflector, it does not introduce astigmatism into the image. However, the windshield 13 on a real vehicle is typically curved and has non-uniform curvature in both the radial (also known as the meridional direction) and tangential (also known as the sagittal direction) directions. This difference in the radial and tangential surface shape of the windshield 13 introduces astigmatism. Figure 3 A schematic diagram illustrating astigmatism introduced by the windshield is shown. Figure 3 As shown, due to the difference in the radial and tangential surface shape of the windshield, after the diverging light emitted by the point light source is reflected by the windshield 13, the tangential light and the radial light converge at different positions in front of the vehicle, and both deviate from the position of the optimal image plane.
[0064] In an alternative embodiment, to compensate for the astigmatism introduced by the windshield 13, the second freeform optical element 122 is typically designed with the windshield's surface shape in mind in order to pre-correct the astigmatism caused by the windshield 13. In this case, the curvature of the second freeform optical element 122 depends primarily on the curvature of the windshield 13, while the curvature of the first freeform optical element 121 can be designed to gradually increase from the incident position of the ray 4 corresponding to the near end 141 on the first freeform optical element 121 to the incident position of the ray 5 corresponding to the far end 142 on the first freeform optical element 121, so that the final formed first virtual image 14 can substantially conform to the road surface.
[0065] In one or more embodiments of this disclosure, the curvature of the first free-form optical element 121 can smoothly change from one end to the other. In alternative embodiments, the curvature of the first free-form optical element 121 can be varied by splicing together multiple first sub-free-form optical elements. The curvatures of the different first sub-free-form optical elements are different, and each first sub-free-form optical element may have a single curvature or a gradually changing or gradient curvature.
[0066] Return to reference Figure 2 In some embodiments of this disclosure, the second free-form optical element 122 is arranged such that the first virtual image 14 is inverted relative to the first source image, such that light rays corresponding to the distal end 142 of the first virtual image 14 originate from the bottom of the first source image, and light rays corresponding to the proximal end 141 originate from the top of the first source image. That is, light rays emitted from the lower end of the image generation unit 11 are projected onto the distal end 142 of the first virtual image 14, while light rays emitted from the upper end of the image generation unit 11 are projected onto the proximal end 141 of the first virtual image 14, meaning that the first virtual image 14 is an inverted virtual image. To make the first virtual image 14 an upright virtual image, the first source image can be set to be inverted.
[0067] In some embodiments of this disclosure, the first image information may include navigation information, instrument panel information, or a combination of both.
[0068] As described above, in the embodiments of this disclosure, by reasonably configuring the optical components 12 to project an image that is substantially flush with the road surface, the augmented reality experience can be improved. Furthermore, as described in detail below, embodiments of this disclosure can also project images to a greater distance to prevent eye fatigue caused by frequent switching between near and far objects.
[0069] Return to reference Figure 1 In related technologies, the distance to the virtual image formed by a head-up display (HUD) is typically non-adjustable, and the virtual image is projected relatively close to the vehicle, for example, 2-3 meters from the driver's eye level and slightly below and in front of the driver's eye level. However, in actual driving environments, to ensure driving safety, drivers usually focus their gaze at a more distant location in front of the vehicle (e.g., 6-10 meters) to clearly observe the surrounding environment. This results in a misalignment between the virtual image's projection position and the driver's eye's focusing position. Figure 1As shown, suppose a driver is looking at a distant object A at a certain moment. If the driver then wants to view the image formed by the head-up display, his / her eyes need to adjust from the distant object to the closer image, which will cause eye fatigue. In addition, this frequent adjustment of the eye's focus position can also cause distraction, thus creating a driving safety hazard.
[0070] Figure 1 The distance PD between the virtual image and the eyebox can be expressed by the following formula:
[0071] PD∝(S1+S1)*M2+S3*M3+S4(1)
[0072] Where S4 represents the distance between the windshield 3 and the eyepiece 2, it visually describes how far the virtual image moves as the driver moves backward. Therefore, there is no magnification effect of optical devices between this object distance S4 and its conjugate virtual image distance. S3 represents the distance between the curved mirror 6 and the windshield 3. M3 represents the magnification (virtual image distance) of the windshield 3 relative to distance S3. Due to the converging reflection of the concave surface of the windshield 3, when the human eye observes the curved mirror 6 through the windshield, the virtual image distance = S3 * M3 + S4. S2 represents the distance between the plane mirror 1 and the curved mirror 6. S1 represents the distance between the image generator 7 and the plane mirror 1. M2 represents the overall magnification of the plane mirror 6 and the windshield 3 relative to (S1 + S2). The plane mirror 1 has no magnification effect on S1.
[0073] As can be seen from equation (1), the distance of the virtual image is related to the magnification of the optical elements and the distance between the optical elements. Therefore, in order to extend the projection distance of the virtual image, one can: 1) increase the magnification of the head-up display device; 2) extend the optical path between the windshield 3 and the image generation unit.
[0074] Return to reference Figure 2 In some embodiments of this disclosure, Figure 1 In the related art shown, the plane mirror 1 is replaced by a first freeform surface optical element 121 with curvature. The first freeform surface optical element 121 with curvature can have a certain magnification of the optical path located upstream of the optical path, thus extending the projection distance of the first virtual image 14.
[0075] In addition, by setting a plane mirror 123 between the image generation unit 11 and the first freeform surface optical element 121, the optical path between the image generation unit 11 and the first freeform surface optical element 121 can be extended, thereby further extending the projection distance of the first virtual image 14.
[0076] The head-up display device in the embodiments of this disclosure can not only make the image plane of the first virtual image 14 substantially parallel to the ground, but also extend the distance between the image plane and the vehicle, thereby reducing eye fatigue and safety hazards.
[0077] In the example embodiment, the distance between the first virtual image 14 and the vehicle can be 3-12 meters.
[0078] In some embodiments of this disclosure, the image generation unit 11 may be any component capable of generating and projecting light carrying first image information of a first source image to be projected. Figure 4 A cross-sectional view of an exemplary image generation unit in one or more embodiments of this disclosure is schematically shown. In example embodiments, such as Figure 4 As shown, the image generation unit 11 may include a light source 151, a display unit 111, and a light guide 152 located in the optical path between the light source 151 and the display unit 111.
[0079] In one or more embodiments, the light source 151 can be a point light source, a line light source, or a surface light source. The number of light sources 151 can be one or more. Specifically, the light source 151 can include one or more light-emitting elements, including but not limited to light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), micro LEDs, cold cathode fluorescent lamps (CCFLs), cold LED lights (CLLs), electroluminescent (ELs), or quantum dot (QDs).
[0080] The display unit 111 can convert the light emitted by the light source 151 into image light including image information, which can form an image directly or after reflection, refraction, etc. The display unit 111 can be at least one of liquid crystal display unit (LCD), digital micromirror device (DMD), cathode ray imaging device (CRT) or silicon-based liquid crystal display device (LCoS).
[0081] The light guide 152 is used to modulate the light emitted from the light source 151 so that the light is incident on the display unit 111 located downstream of its optical path with a specific exit angle or intensity distribution. In an example embodiment, the light guide 152 may include one or more reflective, refractive, or scattering optical elements to modulate the light for each pixel on the display unit 111 so that the light emitted from the light guide has a specific exit intensity or specific exit angle for each pixel, thereby achieving uniform brightness distribution when viewing the first virtual image 14 from within the eye box.
[0082] In one or more embodiments of this disclosure, the light guide 152 may have a first surface 1521 facing the display unit 111 and a second surface 1522 opposite to the first surface 1521. For example... Figure 2 As shown, the first surface 1521 can be parallel to the second surface 1522.
[0083] Continue to refer to Figure 4 In optional embodiments, the image generation unit 11 may further include a heat sink 153 and a lens element 154. The heat sink 153 may be located on the side of the light source 151 away from the light guide to dissipate heat from the image generation unit 11. The lens element 154 may collimate the light emitted by the light source 151. In some embodiments of this disclosure, the lens element 154 may be a component separate from the light guide 152, or it may be integrated into the light guide 152 as one of its components.
[0084] Figure 5 Another head-up display device 50 and its associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 5 The head-up display device 50 shown in the figure and Figure 2 The head-up display devices 20 shown in the figure share some similarities, and relative to Figure 2 The description provided is applicable as appropriate. Figure 5 The head-up display device 50 shown in the figure.
[0085] Figure 5 The head-up display device 50 in the illustrated embodiment and Figure 2 The difference in the head-up display device 20 shown is that, in this embodiment, the first surface 1521 is inclined relative to the second surface 1522, that is, there is a certain angle between the first surface 1521 and the second surface 1522, such that the distance from the first surface 1521 to the second surface 1522 on the side from which the light ray 5 corresponding to the far end 142 of the first virtual image 14 originates is less than the distance from the first surface 1521 to the second surface 1522 on the side from which the light ray 4 corresponding to the near end 141 of the first virtual image 14 originates. Accordingly, the light-emitting surface of the display unit 111 is oriented parallel to the first surface 1521.
[0086] In an example embodiment of this disclosure, the first surface 1521 is tilted at an angle of not less than 25 degrees relative to the second surface 1522.
[0087] In the embodiments of this disclosure, the first surface 1521 of the light guide 152 and the light-emitting surface of the display unit 111 are aligned. Figure 5 The arrangement shown is tilted relative to the second surface 1522. This arrangement can extend the optical path between the image generation unit 11 and the windshield 13, which corresponds to the far end 142 of the first virtual image 14, thereby projecting the far end of the first virtual image to a more distant position.
[0088] Therefore, in the embodiments of this disclosure, by appropriately configuring the curvature distribution of one or more elements in the optical assembly 12 (e.g., the first free-form optical element 121), the distal end 142 of the first virtual image 14 can be projected to a more distant position relative to the proximal end 141, thereby causing the first virtual image 14 to be tilted relative to the road surface. Furthermore, by tilting the first surface 1521 of the light guide 152 and the light-emitting surface of the display unit 111 at an appropriate angle relative to the second surface 1522, the distal end 142 of the first virtual image 14 can be projected to an even more distant position relative to the proximal end 141, thereby achieving an image plane of the first virtual image 14 that is substantially parallel to the road surface.
[0089] In addition, tilting the first surface 1521 of the light guide 152 and the light-emitting surface of the display unit 111 at an appropriate angle relative to the second surface 1522 can also prevent sunlight from flowing back onto the surface of the display unit 111 and being reflected off the surface of the display unit 111 and emitted with the image light, thereby causing problems such as "white screen" and glare.
[0090] Figure 6 Another head-up display device 60 and its associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 6 The head-up display device 60 shown in the figure and Figure 2 The head-up display devices 20 shown in the figure share some similarities, and relative to Figure 2 The description provided is applicable as appropriate. Figure 6 The head-up display device 60 shown in the figure.
[0091] Figure 6 The head-up display device 60 in the illustrated embodiment and Figure 2 The difference in the head-up display device 20 shown is that the optical component 12 of the head-up display device 60 further includes a wedge mirror 124 located on one side of the light-emitting surface 1101 of the image generating unit 11. This wedge mirror 124 can be arranged such that light 5 from the image generating unit 11, corresponding to the distal end 142 of the first virtual image 14, is transmitted through the thicker portion of the wedge mirror 124, while light 4 from the image generating unit 11, corresponding to the proximal end 141 of the first virtual image 14, is transmitted through the thinner portion of the wedge mirror 124. Specifically, in Figure 6 In the illustrated embodiment, since the light 5 corresponding to the far end 142 of the first virtual image 14 is emitted from the lower part of the image generation unit 11, and the light 4 corresponding to the near end 141 of the first virtual image 14 is emitted from the upper part of the image generation unit 11, the thicker part of the wedge mirror 124 corresponds to the lower part of the image generation unit 11, while the thinner part of the wedge mirror 124 corresponds to the upper part of the image generation unit 11.
[0092] It is known that the optical path length of light in a medium is equal to the refractive index of the medium multiplied by the distance the light travels in the medium. Since the thickness of the wedge mirror 124 gradually changes from one end to the other, the optical path length of light passing through different parts of the wedge mirror 124 is different. The optical path length through the thicker part of the wedge mirror 124 is longer, while the optical path length through the thinner part of the wedge mirror 124 is shorter. Therefore, the above arrangement of the wedge mirror 124 allows the light ray 5 corresponding to the far end 142 of the first virtual image 14 to be projected to a farther distance, while the light ray 4 corresponding to the near end 141 of the first virtual image 14 is projected to a closer distance. Therefore, the image plane of the final formed first virtual image 14 can be tilted relative to the ground.
[0093] In some embodiments of this disclosure, such as Figure 6 As shown, the surface of the wedge mirror 124 away from the image generation unit 11 can be a plane. In other embodiments, at least a portion of the surface of the wedge mirror 124 away from the image generation unit 11 can be an outwardly projecting curved surface. Figure 7 A wedge-shaped mirror with a curved surface is schematically illustrated in one or more embodiments of this disclosure. For example... Figure 7 As shown, the inclined surface of the wedge mirror 124 is a convex surface that protrudes outward. The curvature of this convex surface can be designed such that the ray 4 from the image generation unit 11 corresponding to the near end 141 exits the wedge mirror 124 from the position where the ray 5 from the image generation unit 11 corresponding to the far end 142 exits the wedge mirror 124. With this setting, the distance between the far end 142 of the first virtual image 14 and the vehicle can be further extended, making the first virtual image 14 more inclined relative to the ground, or even parallel to the ground.
[0094] Figure 8 Another head-up display device 80 and its associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 8 The head-up display device 80 shown in the figure and Figure 6 The head-up display devices 60 illustrated in the figure share some similarities, and relative to Figure 6 The description provided is applicable as appropriate. Figure 8 The head-up display device 80 shown in the figure.
[0095] and Figure 6 The embodiment shown differs from the one described above in that... Figure 8In the illustrated embodiment, the image generation unit 11 may be further configured to generate light carrying second image information of the second source image to be projected. In this embodiment, the optical component 12 is further configured to redirect the light carrying the second image information from the image generation unit 11 to the windshield 13, so that the windshield 13 reflects the light from the optical component 12 to form a second virtual image 16 of the second source image in front of the vehicle. The distance of the second virtual image 16 from the vehicle is less than the distance of the first virtual image 14 from the vehicle.
[0096] In some embodiments of this disclosure, to achieve better augmented reality effects, the first virtual image 14 can have a small look-down angle (LDA), typically less than 3.5 degrees, allowing it to be projected onto a distant road environment. The second virtual image 16, on the other hand, is typically projected closer to the vehicle, thus allowing it to have a larger LDA. In embodiments of this disclosure, the look-down angle generally refers to the angle between the horizontal plane and the line of sight when looking directly at the center point of the virtual image. The look-down angle of the first virtual image 14 is the angle between the horizontal plane and the line of sight when looking directly at the center point of the first virtual image 14, and the look-down angle of the second virtual image 16 is the angle between the horizontal plane and the line of sight when looking directly at the center point of the second virtual image 16.
[0097] In some embodiments of this disclosure, the first virtual image 14 may include navigation-related information, while the second virtual image 16 may include information related to the vehicle's instrument panel. For example, navigation-related information may include route markers, distance to the next intersection, etc., while information related to the vehicle's instrument panel may include road conditions, vehicle speed, speed limit, fuel level, battery level, etc.
[0098] In some embodiments of this disclosure, the image plane of the second virtual image 16 may be substantially perpendicular to the road surface. However, other embodiments are also possible. For example, the second virtual image 16 may also be parallel to the road surface or at an acute angle, but compared to the first virtual image 14, the second virtual image 16 may be closer to the vehicle.
[0099] In some embodiments of this disclosure, the simultaneous projection of two virtual images can be achieved in any manner. In an example embodiment, the optical elements in the optical assembly 12 can be partitioned such that a first region is used to project the first virtual image 14, and a second region is used to project the second virtual image 16. In another example embodiment, two sets of optical assemblies 12 can be provided, with a first set of optical assemblies used to project the first virtual image 14 and a second set of optical assemblies used to project the second virtual image.
[0100] It should be noted that, Figure 2 The head-up display shown can also be configured to simultaneously project the first virtual image 14 and the second virtual image 16. Further details will not be provided here.
[0101] Figure 9 Another head-up display device 90 and associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 9 The head-up display device 90 shown in the figure and Figure 2 , Figure 5-6 , Figure 8 The head-up display devices 20, 50, 60, and 80 illustrated in the figure share some similarities and are relative to... Figure 2 , Figure 5-6 , Figure 8 The description provided is applicable as appropriate. Figure 9 The head-up display device 90 shown in the figure.
[0102] like Figure 9 As shown, the head-up display device 90 may include an image generation unit 21 and an optical component 22. The image generation unit 21 is configured to generate and project light carrying first image information of a first source image to be projected toward the optical component 22; the optical component 22 is configured to redirect the light from the image generation unit 21 onto the windshield 23 of the vehicle, so that the windshield 23 can reflect the light from the optical component 22 to form a first virtual image 24 of the first source image in front of the vehicle.
[0103] Continue to refer to Figure 9 The first virtual image 24 has a near end 241 closer to the vehicle and a far end 242 farther from the vehicle. In this embodiment, the image generation unit 21 is configured such that the light path between the image generation unit 21 and the windshield 23 for the first virtual image 24 gradually increases in length from the ray 4 corresponding to the near end 241 to the ray 5 corresponding to the far end 242. That is, the optical path length of the ray 4 corresponding to the near end 241 of the first virtual image 24 is shorter than the optical path length of the ray 5 corresponding to the far end 242, and the optical path length of the ray between the ray 4 and the ray 5 gradually increases from the ray 4 to the ray 5 between the image generation unit 21 and the windshield 23.
[0104] In one or more of the disclosed embodiments, the optical path between the image generation unit 21 and the windshield 23 gradually lengthens from the ray 4 corresponding to the near end 241 of the first virtual image 24 to the ray 5 corresponding to the far end 242, in such a way that the image plane in which the first virtual image 24 is located is substantially in contact with the road surface.
[0105] The image plane of the first virtual image 24 is basically aligned with the road surface, enabling the projection of information displayed on the image onto the road surface, which enhances the augmented reality experience. Furthermore, projecting the image onto the road surface is less likely to obstruct the driver's view, thus improving driving safety.
[0106] In one or more embodiments of this disclosure, the image generation unit 21 has a light-emitting surface 2101 facing at least a portion of the optical component 22. The light-emitting surface 2101 may be oriented such that the light path between the image generation unit 21 and the windshield 23 for the first virtual image 24 gradually lengthens from the ray 4 corresponding to the near end 241 of the first virtual image 24 to the ray 5 corresponding to the far end 242 of the first virtual image 24.
[0107] exist Figure 9 In the specific embodiment shown, the light emitted from the lower end of the light-emitting surface 2101 of the image generation unit 21 corresponds to the far end 242 of the first virtual image 24, while the light emitted from the upper end of the light-emitting surface 2101 of the image generation unit 21 corresponds to the near end 241 of the first virtual image 24. Therefore, compared to the near end 241, in order to project the light from the far end 242 further, the lower end of the light-emitting surface 2101 of the image generation unit 21 can be closer to the surface of the image generation unit 21 opposite to the light-emitting surface 2101, so as to extend the optical path of the light emitted from the lower end of the light-emitting surface 2101 of the image generation unit 21 between the image generation unit 21 and the windshield 23, thereby projecting the light corresponding to the far end 242 to a farther place. Therefore, by reasonably setting the orientation of the image generation unit 21, the image plane of the first virtual image 24 can be basically horizontally oriented, so as to basically fit the road surface.
[0108] In the example embodiment, such as Figure 9 As shown, the image generation unit 21 may include a light source 251, a display unit 211, and a light guide 252 located in the optical path between the light source 251 and the display unit 211.
[0109] In one or more embodiments, the light source 251 can be a point light source, a line light source, or a surface light source. The number of light sources 251 can be one or more.
[0110] The display unit 211 can convert the light emitted by the light source 251 into image light that includes image information, which can form an image directly or after reflection, refraction and other processes.
[0111] The light guide 252 is used to modulate the light emitted from the light source 251 so that the light is incident on the display unit 211 located downstream of its optical path with a specific exit angle or intensity distribution. In an example embodiment, the light guide 252 may include one or more reflective, refractive, or scattering optical elements to modulate the light for each pixel on the display unit 211 so that the light emitted from the light guide has a specific exit intensity or specific exit angle for each pixel, thereby achieving uniform brightness distribution when viewing the first virtual image 24 from within the eye box.
[0112] In one or more embodiments of this disclosure, the light guide 252 may have a first surface 2521 facing the display unit 211 and a second surface 2522 opposite to the first surface 2521. The first surface 2521 is inclined relative to the second surface 2522 such that the distance from the first surface 2521 to the second surface 2522 on the side from which the light ray 5 corresponding to the distal end 242 of the first virtual image 24 originates is less than the distance from the first surface 2521 to the second surface 2522 on the side from which the light ray 4 corresponding to the proximal end 241 of the first virtual image 24 originates. Accordingly, the light-emitting surface of the display unit 211 is oriented parallel to the first surface 2521.
[0113] In an example embodiment of this disclosure, the first surface 2521 is tilted at an angle of not less than 25 degrees relative to the second surface 2522.
[0114] In the embodiments of this disclosure, the first surface 2521 of the light guide 252 and the light-emitting surface of the display unit 211 are aligned with... Figure 9 The arrangement shown is tilted relative to the second surface 2522. This arrangement extends the optical path between the image generation unit 21 and the windshield 23, corresponding to the distal end 242 of the first virtual image 24. This allows the distal end 242 of the first virtual image 24 to be projected to a more distant position, making the image plane of the first virtual image 24 tilted relative to the road surface. By tilting the first surface 2521 of the light guide 252 and the light-emitting surface of the display unit 211 at an appropriate angle relative to the second surface 2522, the image plane of the first virtual image 24 can be made substantially parallel to the road surface.
[0115] Referring again to reference 9, the image generation unit 21 may further include a heat sink 253 and a lens element 254. The heat sink 253 may be located on the side of the light source 251 away from the light guide 252 in order to dissipate heat from the image generation unit 21. The lens element 254 may collimate the light emitted by the light source 251.
[0116] Referring again to 9, the optical assembly 22 may include a plane mirror 223 and a freeform optical element 221. The plane mirror 223 may be configured to redirect light from the image generation unit 21 toward the freeform optical element 221; the freeform optical element 221 may be configured to redirect light from the plane mirror 223 toward the windshield 23.
[0117] and Figure 5 The optical assembly 12 of the head-up display device 50 illustrated in the figure includes two free-form optical elements of different shapes. Figure 9 The optical assembly 22 of the head-up display device 90 shown includes only one freeform optical element 221. This freeform optical element 221 is an aspherical mirror with non-uniform curvature. In this embodiment, the freeform optical element 221 is configured to pre-correct astigmatism caused by the windshield 23.
[0118] In one or more embodiments of this disclosure, the plane mirror 223 can be used to fold the optical path between the image generation unit 21 and the windshield 23 in order to extend the object distance between the image generation unit 21 and the windshield 23, thereby projecting the first virtual image 24 to a place farther away from the vehicle, and at the same time reducing the space occupied by the optical path between the image generation unit 21 and the windshield 23.
[0119] and Figure 2 , Figure 5 , Figure 6 and Figure 8 The illustrated embodiments are similar, in Figure 9 In the illustrated embodiment, the freeform optical element 221 is arranged such that the first virtual image 24 is inverted relative to the first source image, such that light rays corresponding to the distal end 242 of the first virtual image 24 originate from the bottom of the first source image, and light rays corresponding to the proximal end 241 originate from the top of the first source image. That is, light rays emitted from the lower end of the image generation unit 21 are projected onto the distal end 242 of the first virtual image 24, while light rays emitted from the upper end of the image generation unit 21 are projected onto the proximal end 241 of the first virtual image 24, meaning that the first virtual image 24 is an inverted virtual image. To make the first virtual image 24 an upright virtual image, the first source image can be set to be inverted.
[0120] Figure 10 Another head-up display device 100 and associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 10 The head-up display device 100 shown in the figure and Figure 6 and Figure 9 The head-up display devices 60 and 90 shown in the figure share some similarities, and are relative to Figure 6 and Figure 9 The description provided is applicable as appropriate. Figure 10 The head-up display device 100 shown in the figure.
[0121] and Figure 9 The embodiment shown differs from the one described above in that... Figure 10 In the illustrated embodiment, the optical component 22 further includes a wedge-shaped mirror 224 located on one side of the light-emitting surface 2101 of the image generation unit 21. For alternative embodiments of the wedge-shaped mirror 224, please refer to the above description. Figure 6 The wedge mirror 124 in the described embodiment.
[0122] Figure 11 Another head-up display device 110 and associated optical path are schematically shown in one or more embodiments of this disclosure. Figure 11 The head-up display device 110 shown in the figure and Figure 8 and Figure 9The head-up display devices 80 and 90 shown in the figure share some similarities, and are relative to Figure 8 and Figure 9 The description provided is applicable as appropriate. Figure 11 The head-up display device 110 shown in the figure.
[0123] and Figure 9 The embodiment shown differs from the one described above in that... Figure 11 In the illustrated embodiment, the image generation unit 21 may be further configured to generate light carrying second image information of the second source image to be projected. In this embodiment, the optical component 22 is further configured to redirect the light carrying the second image information from the image generation unit 21 to the windshield 23, so that the windshield 23 reflects the light from the optical component 22 to form a second virtual image 26 of the second source image in front of the vehicle. The distance of the second virtual image 26 from the vehicle is less than the distance of the first virtual image 24 from the vehicle.
[0124] For alternative embodiments of the second virtual image 26, please refer to the above section on... Figure 8 The second virtual image 16 in the described embodiment.
[0125] Embodiments of this disclosure also provide a vehicle. The vehicle may include at least one head-up display device according to this disclosure, such as at least one head-up display device according to one or more embodiments disclosed in detail above. Therefore, for alternative embodiments of the vehicle, reference may be made to embodiments of the head-up display device.
[0126] Figure 12 A block diagram of a vehicle according to one or more embodiments of this disclosure is shown schematically. Figure 12 As shown, the vehicle may include any of the head-up display devices 20, 50, 60, 80, 90, 100, 110 described in the above embodiments relating to the head-up display device. The vehicle may include windshields 13, 23, which are configured to form a first virtual image 14, 24 of the first source image in front of the vehicle by reflecting light carrying first image information of the first source image to be projected from the head-up display devices 20, 50, 60, 80, 90, 100, 110.
[0127] It should be noted that the optical path shown in the accompanying drawings of this disclosure is merely schematic, and the actual optical path depends on the specific arrangement of the optical elements. In order to form a virtual image in front of the vehicle, the light emitted from the light source can be made perpendicular to the light-emitting surface of the light source. After passing through optical elements such as light guides and display units (e.g., LCDs), the light rays exit at an angle to the surface of the display unit. The light emitted from the display unit is divergent light.
[0128] The foregoing description of embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of the present application. Various elements or features of a particular embodiment are generally not limited to that particular embodiment; however, these elements and features are interchangeable and can be used in chosen embodiments where appropriate, even if not specifically shown or described. Changes are also possible in many ways. Such changes should not be considered as departing from the present application, and all such modifications are included within the scope of this application.
Claims
1. A head-up display device, comprising an image generation unit (11, 21) and optical components (12, 22), wherein: The image generation units (11, 21) are configured to generate and project light carrying first image information of the first source image to be projected toward the optical components (12, 22); The optical components (12, 22) are configured to redirect the light from the image generation unit (11, 21) onto the windshield (13, 23) of the vehicle, such that the windshield (13, 23) reflects the light from the optical components (12, 22) to form a first virtual image (14, 24) of the first source image in front of the vehicle. The first virtual image (14, 24) has a near end (141, 241) closer to the vehicle and a far end (142, 242) farther from the vehicle. At least one of the optical components (12, 22) and the image generation unit (11, 21) is further configured such that the light path between the image generation unit (11, 21) and the windshield (13, 23) for the first virtual image (14, 24) gradually lengthens from the ray (4) corresponding to the near end (141, 241) to the ray (5) corresponding to the far end (142, 242). The optical component (12) includes: a plane mirror (123), a first free-form optical element (121), and a second free-form optical element (122), wherein, The planar mirror (123) is configured to redirect the light from the image generation unit (11) toward the first free-form optical element (121); The first freeform optical element (121) is configured to redirect the light from the planar mirror (123) toward the second freeform optical element (122); and The second free-form optical element (122) is configured to redirect light from the first free-form optical element (121) toward the windshield (13). Wherein, the first free-form optical element (121) and the second free-form optical element (122) are aspherical mirrors with non-uniform curvature, and The curvature of at least one of the first free-form optical element (121) and the second free-form optical element (122) gradually increases from the position where the ray (4) corresponding to the near end (141) is incident on the corresponding free-form optical element to the position where the ray (5) corresponding to the far end (142) is incident on the corresponding free-form optical element.
2. The head-up display device according to claim 1, wherein, The optical path between the image generation unit (11, 21) and the windshield (13, 23) gradually lengthens in such a way that the image plane in which the first virtual image (14, 24) is located is substantially in contact with the road surface.
3. The head-up display device according to claim 1 or 2, wherein, The image generating unit (11, 21) has a light-emitting surface (1101, 2101) facing at least a portion of the optical component (12, 22), and the light-emitting surface (1101, 2101) of the image generating unit (11, 21) is oriented such that the light path between the image generating unit (11, 21) and the windshield (13, 23) and for the first virtual image (14, 24) gradually lengthens from the ray (4) corresponding to the near end (141, 241) to the ray (5) corresponding to the far end (142, 242).
4. The head-up display device according to claim 3, wherein, The image generation units (11, 21) include: Light source (151, 251); Display units (111, 211) are located in the optical path between the light source (151, 251) and the optical components (12, 22), wherein the light-emitting surface of the display units (111, 211) is the light-emitting surface (1101, 2101) of the image generating units (11, 21); and Light guides (152, 252) are located in the optical path between the light source (151, 251) and the display unit (111, 211), and the light guides (152, 252) are configured to guide light from the light source (151, 251) to the display unit (111, 211). The light guides (152, 252) have a first surface (1521, 2521) facing the display units (111, 211) and a second surface (1522, 2522) opposite to the first surface (1521, 2521). The first surface (1521, 2521) is inclined relative to the second surface (1522, 2522) such that the distance from the first surface (1521, 2521) to the second surface (1522, 2522) on the side from which the light ray (5) corresponding to the far end (142, 242) originates is less than the distance from the first surface (1521, 2521) to the second surface (1522, 2522) on the side from which the light ray (4) corresponding to the near end (141, 241) originates. The light-emitting surfaces of the display units (111, 211) are oriented to be parallel to the first surfaces (1521, 2521).
5. The head-up display device according to claim 4, wherein, The angle of inclination of the first surface (1521, 2521) relative to the second surface (1522, 2522) is not less than 25 degrees.
6. The head-up display device according to claim 1, wherein, The curvature of the first free-form optical element (121) gradually increases from the position where the ray (4) corresponding to the near end (141) is incident on the first free-form optical element to the position where the ray (5) corresponding to the far end (142) is incident on the first free-form optical element, and the second free-form optical element (122) is further configured to pre-correct astigmatism caused by the windshield (13).
7. The head-up display device according to claim 1, wherein, The first source image is an inverted image, and wherein the second free-form optical element (122) is further arranged such that the first virtual image (14) is inverted relative to the first source image, such that the ray (5) corresponding to the far end (142) originates from the bottom of the first source image, and the ray (4) corresponding to the near end (141) originates from the top of the first source image.
8. The head-up display device according to claim 1 or 2, wherein, The optical components (12, 22) further include a wedge mirror (124, 224) disposed on one side of the light-emitting surface (1101, 2101) of the image generating unit (11, 21), the wedge mirror (124, 224) being arranged such that light rays (5) from the image generating unit (11, 21) corresponding to the distal end (142, 242) are transmitted through the thicker portion of the wedge mirror (124, 224), and light rays (4) from the image generating unit (11, 21) corresponding to the proximal end (141, 241) are transmitted through the thinner portion of the wedge mirror (124, 224).
9. The head-up display device according to claim 8, wherein, At least a portion of the surface of the wedge mirrors (124, 224) that is away from the image generation unit (11, 21) is an outwardly projecting curved surface.
10. The head-up display device according to claim 9, wherein, The curvature of the surface is designed such that the position from which the light ray (4) from the image generation unit (11, 21) and corresponding to the near end (141, 241) exits the wedge mirror (124, 224) gradually increases to the position from which the light ray (5) from the image generation unit (11, 21) and corresponding to the far end (142, 242) exits the wedge mirror (124, 224).
11. The head-up display device according to claim 1 or 2, wherein, The image generation units (11, 21) are further configured to generate light carrying second image information of the second source image to be projected. The optical components (12, 22) are further configured to redirect light carrying the second image information from the image generation unit (11, 21) to the windshield (13, 23), so that the windshield (13, 23) can reflect the light from the optical components (12, 22) to form a second virtual image (16, 26) of the second source image in front of the vehicle, wherein the distance between the second virtual image (16, 26) and the vehicle is less than the distance between the first virtual image (14, 24) and the vehicle.
12. The head-up display device according to claim 11, wherein, The image plane of the second virtual image (16, 26) is substantially perpendicular to the road surface.
13. A vehicle comprising a windshield (13, 23) and a head-up display (20, 50, 60, 80, 90, 100, 110) according to any one of claims 1 to 12, said windshield (13, 23) being configured to form a first virtual image (14, 24) of the first source image in front of the vehicle by reflecting light carrying first image information of a first source image to be projected from said head-up display (20, 50, 60, 80, 90, 100, 110).