Head-up display device

Abstract

The present disclosure relates to a head-up display device, comprising an image generating unit, a first reflecting element and a second reflecting element. The image generating unit emits image light, the image light comprising light rays corresponding to different fields of view. The first reflecting element is disposed on the light emitting side of the image generating unit and has a first reflecting surface profile to receive and reflect the image light. The second reflecting element is disposed on the reflected light path of the first reflecting element and has a second reflecting surface profile to receive the image light reflected by the first reflecting element and reflect the image light reflected by the first reflecting element to an imaging window. The light rays corresponding to different fields of view in the image light cross each other between the first reflecting element and the second reflecting element after being reflected by the first reflecting element to form a cross light path region, wherein the image light propagates to the second reflecting element through the cross light path region. In this way, the light path envelope between the reflecting elements can be narrowed, thereby reducing the volume of the head-up display device.

Description

Technical Field

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

[0002] With the development of smart cockpits and driver assistance technologies, head-up display (HUD) devices need to display information such as navigation, vehicle speed, warnings, and lane prompts in front of the driver. To expand the space where information can be displayed, HUD devices typically need to provide a large field of view and a large eye box area. Summary of the Invention

[0003] This application provides a head-up display device that can narrow the optical path envelope between the first reflective element and the second reflective element while satisfying a large field of view and a large eye box range, thereby reducing the space occupied by the head-up display device.

[0004] According to one aspect of this application, a head-up display (HUD) device is provided. The HUD device includes an image generating unit, a first reflective element, and a second reflective element. The image generating unit emits image light, which includes light rays corresponding to different fields of view. The first reflective element is disposed on the light-emitting side of the image generating unit and has a first reflective surface profile to receive and reflect the image light. The second reflective element is disposed in the reflective light path of the first reflective element and has a second reflective surface profile to receive the image light reflected by the first reflective element and further reflect the image light reflected by the first reflective element to an imaging window. The light rays corresponding to different fields of view in the image light, after being reflected by the first reflective element, intersect between the first and second reflective elements to form an intersecting light path region. The image light propagates to the second reflective element through the intersecting light path region. Attached Figure Description

[0005] The features and advantages of embodiments of this application will become more readily understood from the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific components. In the drawings: Figure 1 This is a schematic diagram of a head-up display device according to an embodiment of this application.

[0006] Figure 2 for Figure 1 A three-dimensional schematic diagram of the cross-optical path structure.

[0007] Figure 3 This is another schematic diagram of a head-up display device according to an embodiment of this application.

[0008] Figure 4This is a schematic diagram illustrating the minimum distance between the effective reflection area of ​​the first reflective element and the light emission envelope of the second reflective element.

[0009] Figure 5 This is a schematic diagram of a head-up display device according to another embodiment of this application.

[0010] Figure 6 This is a schematic diagram of the path through which external light rays flow back to the image generation unit along the opposite path of the image light.

[0011] Figure 7 This is a schematic diagram of an image generation unit according to an embodiment of this application.

[0012] Figure 8 for Figure 1 A schematic diagram showing the dimensions of the first reflective element, the second reflective element, and the cross-optical path region within a cross section corresponding to the short side direction.

[0013] Figure 9 A schematic diagram illustrating the definition of the curvature of the first and second reflective surface profiles.

[0014] Figure 10 This is a schematic diagram illustrating the optical path from the first reflective element to the second reflective element and the optical path from the cross-optical path region to the first reflective element.

[0015] In the accompanying drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. Detailed Implementation

[0016] The present application will now be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that the following detailed description of the present application is for illustrative purposes only and is not intended to limit the scope of the application.

[0017] It should be noted that, for clarity, not all features of a particular embodiment are described or shown in the specification and drawings. Furthermore, to avoid unnecessary details obscuring the technical solutions of interest in this application, only the device structure closely related to the technical solutions of this application is described and shown in the specification and drawings, while other details that are not closely related to the technical content of this application and are known to those skilled in the art are omitted.

[0018] To facilitate understanding of the head-up display device 100 of the embodiments of this application, the following will first refer to... Figure 1 The relevant optical path relationships are explained.

[0019] The head-up display device 100 can be applied to vehicles. The head-up display device 100 may include a picture generation unit (PGU) 120, a first reflective element 140, and a second reflective element 160. The image light S emitted by the picture generation unit 120 may include light rays corresponding to different fields of view. Different fields of view can be understood as sets of light rays in the image light S corresponding to different positions of the display screen 400. The image light S is reflected by the first reflective element 140 and transmitted to the second reflective element 160, and then reflected by the second reflective element 160 to the imaging window 200. The imaging window 200 can reflect the image light S to the eye-box region 300, allowing the observer to observe the virtual image corresponding to the image light S, i.e., the display screen 400.

[0020] In related head-up display devices, image light emitted from the image generation unit is typically reflected by a first reflective element and a second reflective element before being directed towards an imaging window, and then reflected by the imaging window to the eye box area. The image light can include light rays corresponding to different fields of view. When light rays from different fields of view propagate between the first and second reflective elements, the light rays typically propagate approximately parallel or divergently, forming an optical path envelope occupying a certain spatial area.

[0021] As the field of view and eye box range of a head-up display (HUD) increase, the optical path envelope formed between the first and second reflective elements corresponding to different fields of view also increases accordingly. To fully receive and reflect these different fields of view, the effective reflection areas of the first and second reflective elements typically need to be increased as well. Consequently, a larger optical path transmission space needs to be reserved between the first and second reflective elements, potentially increasing the size of the reflective elements and the overall height or depth of the HUD.

[0022] However, the space available for a head-up display (HUD) inside a vehicle's dashboard is limited, and this space is further constrained by factors such as dashboard design, air ducts, reinforcement structures, electrical components, and assembly paths. Therefore, while satisfying a large field of view and a large eye box range, how to narrow the optical path envelope between the first and second reflective elements and reduce the space occupied by the HUD inside the vehicle is a problem that needs to be solved for relevant HUD devices.

[0023] In view of the above problems, this application provides a head-up display device 100. By configuring the first and second reflective surface shapes and the relative arrangement of the first and second reflective elements 140 and 160, light rays corresponding to different fields of view in the image light, after being reflected by the first reflective element 140, can cross between the first and second reflective elements 140 to form a cross-optical path region. Through this cross-optical path design, light rays from different fields of view undergo a converging and crossing process on their transmission path as they travel from the first reflective element 140 to the second reflective element 160. Therefore, the size of the optical path envelope near the cross-optical area can be reduced, thereby decreasing the space required between the first and second reflective elements 140 and 160.

[0024] In the embodiments of this application, the cross-optical path region W formed between the first reflective element 140 and the second reflective element 160 is not a single ideal geometric focal point, but rather a spatial region formed by multiple sets of light rays from different fields of view after they approach, cross, or partially overlap each other between the first reflective element 140 and the second reflective element 160. This cross-optical path region W can correspond to a region where the optical path envelope size formed by light rays from different fields of view reaches a small value or a locally small value.

[0025] In the relevant optical path, light rays corresponding to different fields of view, after being reflected by the first reflecting element 140, typically propagate approximately parallel to each other or gradually diverge between the first reflecting element 140 and the second reflecting element 160. In contrast, the embodiments of this application, by configuring the first and second reflecting surface profiles and the relative arrangement of the first and second reflecting elements 140 and 160, allow light rays corresponding to different fields of view to converge and intersect between the first and second reflecting elements 140 and 160 before propagating to the second reflecting element 160. Therefore, the optical path envelope between the first and second reflecting elements 140 and 160 can be compressed near the intersecting optical path region W.

[0026] Furthermore, since the optical path envelope is compressed between the two reflecting elements, the effective reflection area required for the first reflecting element 140 to receive and reflect light from different fields of view can be reduced accordingly. After the effective reflection area of ​​the first reflecting element 140 is reduced, the physical size of the first reflecting element 140 can be reduced accordingly, or a larger assembly margin and optical path design margin can be obtained under the same physical size.

[0027] Below, refer to Figures 1 to 7 The present application will provide a detailed description of various aspects of the head-up display device 100 according to the embodiments of the present application.

[0028] Continue to refer to Figure 1The image generation unit 120 is configured to emit image light S. Image light S includes light rays corresponding to different fields of view. Different fields of view refer to the sets of light rays in image light S that correspond to different positions or angles of the display screen 400. For example, when the image generation unit 120 generates a complete display screen, the light rays corresponding to different areas of the display screen are emitted along different angular directions, and these sets of light rays at different angular directions constitute the light rays corresponding to different fields of view. In the application scenario of the head-up display device 100, the image light S emitted by the image generation unit 120 carries display information such as navigation, vehicle speed, and warnings. After transmission through the optical system, this information is ultimately presented in the driver's field of vision as a virtual image.

[0029] The first reflective element 140 is disposed on the light-emitting side of the image generation unit 120 and is configured to receive and reflect the image light S emitted from the image generation unit 120. The first reflective element 140 is used to change the propagation direction of the image light S emitted from the image generation unit 120, causing the image light S to propagate towards the second reflective element 160. The first reflective element 140 has a first reflective surface profile, which determines the propagation direction and converging and diverging characteristics of light rays in different fields of view after reflection by the first reflective element 140 in the image light S.

[0030] The second reflective element 160 is configured to receive the image light S reflected by the first reflective element 140 and reflect the image light S to the imaging window 200. The imaging window 200 can be the windshield of a vehicle or a specially designed synthesizer. After being reflected by the imaging window 200, the image light S reaches the eye-box area 300, where the driver can observe the display screen 400 corresponding to the image light S. The second reflective element 160 has a second reflective surface profile, which works in conjunction with the first reflective surface profile to jointly determine the complete optical path characteristics of the image light S from the image generation unit 120 to the imaging window 200.

[0031] In the embodiments of this application, the first reflective surface type, the second reflective surface type, and the relative arrangement of the first reflective element 140 and the second reflective element 160 are configured such that light rays corresponding to different fields of view in the image light S are reflected by the first reflective element 140 and then cross between the first reflective element 140 and the second reflective element 160 to form a cross-optical path region W, and the image light S propagating through the cross-optical path region W is reflected by the second reflective element 160 to the imaging window 200.

[0032] As mentioned earlier, in head-up display devices of related technologies, light rays corresponding to different fields of view typically propagate approximately parallel or divergently when transmitted between the first and second reflective elements. This means that the distance between light rays corresponding to different fields of view remains constant or gradually increases throughout the entire process of transmission from the first reflective element to the second reflective element.

[0033] In this embodiment, by configuring the surface shapes of the first and second reflective surfaces and the relative arrangement of the first and second reflective elements 140 and 160, the light rays corresponding to different fields of view, after being reflected by the first reflective element 140, do not continuously diverge or remain parallel, but instead undergo a process of convergence and intersection along the transmission path. Specifically, after being reflected by the first reflective element 140, the light rays corresponding to different fields of view first gradually converge, intersect each other at the intersection optical path region W, and then gradually diverge and reach the second reflective element 160. Near the intersection optical path region W, because the light rays from different fields of view approach each other and even intersect, the size of the optical path envelope is reduced compared to the case of light rays diverging and propagating.

[0034] The contraction of the optical path envelope near the intersection region W allows for a reduction in the space required between the first reflective element 140 and the second reflective element 160. Under the same field of view and eyebox range, the cross-optical path design allows for a smaller spacing between the first reflective element 140 and the second reflective element 160, or, at the same spacing, a larger field of view and eyebox range, thereby helping to achieve the display requirements of a large field of view and a large eyebox within a compact space.

[0035] Furthermore, since the optical path envelope contracts during transmission, the size of the effective reflection area of ​​the first reflecting element 140 can be reduced accordingly. In related technologies, a large effective reflection area is typically required for the first reflecting element to cover the light rays corresponding to all fields of view. However, in the embodiments of this application, since the light rays from different fields of view begin to converge after being reflected by the first reflecting element 140, the size of the effective reflection area on the first reflecting element 140 can be reduced, thereby helping to reduce the size of the first reflecting element 140.

[0036] Therefore, the light rays corresponding to different fields of view no longer continuously propagate in near parallel or diverge between the first reflective element 140 and the second reflective element 160, but instead converge between the two reflective elements and form a cross-optical path region W. The optical path envelope size near the cross-optical path region W can be narrowed, thereby reducing the optical path transmission space between the two reflective elements and reducing the overall volume of the head-up display device 100.

[0037] Continue to refer to Figure 1In some embodiments, at least one of the first reflecting element 140 and the second reflecting element 160 is a freeform surface mirror. A freeform surface refers to an optical surface that is not constrained by the rotational symmetry of a conventional spherical or aspherical surface, and its surface shape can have different curvature distributions in different directions, thereby having a higher degree of freedom in optical design.

[0038] In some embodiments, both the first reflective element 140 and the second reflective element 160 are freeform surface mirrors. The first reflective element 140 can be positioned relatively close to the image generation unit 120 and can serve as a small mirror; the second reflective element 160 can be positioned relatively close to the imaging window 200 and can serve as a large mirror. The first reflective surface profile of the first reflective element 140 and the second reflective surface profile of the second reflective element 160 can have mutually matching curvature distributions within the surface cross-section corresponding to the short side direction D2 of the display screen 400.

[0039] Through the coordinated configuration of the first and second reflective surface shapes, the first reflective element 140 can cause light rays corresponding to different fields of view to converge towards the cross-optical path region W after leaving the first reflective element 140. The second reflective element 160 can receive the image light S that has been dispersed again after passing through the cross-optical path region W, and reflect the image light S to the imaging window 200 in a suitable direction and angle. Thus, the first reflective element 140 and the second reflective element 160 do not independently change the propagation direction of the image light S, but rather jointly define the optical path envelope between the first reflective element 140 and the second reflective element 160 through surface shape cooperation.

[0040] Understandably, freeform mirrors offer more optimization options in optical path design compared to traditional spherical or aspherical mirrors. In the optical path of the head-up display device 100, light rays from different fields of view in the image light S need to meet specific propagation directions and convergence characteristics after reflection to form the aforementioned intersecting optical path region W. The surface shape of the freeform mirror can be flexibly adjusted according to the needs of the optical path design, allowing for precise control of the reflection angle and convergence effect at different locations.

[0041] For example, the first reflecting element 140 can be a freeform mirror, with its surface shape designed to converge light rays from different fields of view at a specific angle after reflection, thereby forming a cross-optical path region W between the first reflecting element 140 and the second reflecting element 160. Alternatively, the second reflecting element 160 can also be a freeform mirror, with its surface shape designed to reflect the light rays that diverge again after crossing at a suitable direction and angle to the imaging window 200, thereby forming a high-quality virtual image.

[0042] Still refer to Figure 1In some embodiments, the image light S emitted by the image generation unit 120 corresponds to a display screen 400 having a long side direction D1 and a short side direction D2. The long side direction D1 of the display screen 400 typically corresponds to the horizontal direction (i.e., left-right direction) of the vehicle, and the short side direction D2 typically corresponds to the vertical direction (i.e., up-down direction) of the vehicle. For example, in a typical head-up display device, the aspect ratio of the display screen 400 can be approximately 16:5 or other ratios, wherein the longer side extends horizontally and the shorter side extends vertically.

[0043] In some embodiments, the cross-optical path region W is primarily formed in the field of view expansion dimension corresponding to the short side direction D2 of the display screen 400. The short side direction D2 of the display screen 400 may correspond to the vehicle height direction or the vertical display direction of the head-up display virtual image. Since the arrangement space inside the vehicle dashboard in the height and depth directions is usually limited, narrowing the optical path envelope in the field of view expansion dimension corresponding to the short side direction D2 of the display screen 400 can effectively reduce the height or depth dimensions of the head-up display device 100.

[0044] The multiple fields of view distributed along the short side direction D2 may include a first edge field of view, a second edge field of view, and an intermediate field of view located between the first and second edge field of view. The intersecting optical path region W can be jointly defined by the rays corresponding to the multiple fields of view distributed along the short side direction D2, and is not limited to the geometric intersection of any two rays. In other words, the intersecting optical path region W can be understood as the region where the optical path envelope formed between the two reflecting elements by the rays corresponding to the multiple fields of view distributed along the short side direction D2 narrows.

[0045] In the above embodiments, different fields of view include multiple fields of view distributed along the short side direction D2. Multiple fields of view distributed along the short side direction D2 can be understood as fields of view located at different positions in the vertical direction of the displayed image. For example, in... Figure 1 The diagram illustrates that the upper area of ​​the display screen 400 corresponds to one field of view S1, the middle area corresponds to another field of view S2, and the lower area corresponds to yet another field of view S3. These fields of view are arranged and distributed along the short side direction D2.

[0046] In the embodiments of this application, the cross optical path region W ( Figure 1(Schematably shown with dashed circles) The light rays corresponding to multiple fields of view distributed along the short side direction D2 are reflected by the first reflective element 140 and then intersect to form the intersecting light path region W. It can be understood that in the optical path of the head-up display device 100, the light rays corresponding to multiple fields of view S1 distributed along the short side direction D2 of the display screen 400 have different exit angles in the vertical dimension. When these light rays are reflected by the first reflective element 140, due to the configuration of the first reflective surface, the light rays corresponding to fields of view S1 located at different positions along the short side direction D2 are given different reflection angles, causing these light rays to gradually converge and intersect in a certain area during transmission, forming the intersecting light path region W.

[0047] Continue to refer to Figure 1 In some embodiments, the plurality of fields of view distributed along the short side direction D2 includes a first edge field of view and a second edge field of view located on opposite sides of the short side direction D2. The first edge field of view may correspond to one end (e.g., the top end) of the display screen 400 in the short side direction D2, for example... Figure 1 The middle and upper regions correspond to the field of view S1; the second edge field of view may correspond to the other end (e.g., the lower end) of the display screen 400 in the short side direction D2, for example... Figure 1 The field of view S3 corresponds to the middle and lower regions. The first edge field of view and the second edge field of view represent the two outermost fields of view among the multiple fields of view distributed along the short side direction D2, and the angular range between these two fields of view defines the field of view angle of the displayed image in the short side direction D2.

[0048] In the above embodiment, the light rays corresponding to the first edge field of view and the light rays corresponding to the second edge field of view in the image light S are reflected by the first reflective element 140 and then cross between the first reflective element 140 and the second reflective element 160.

[0049] Understandably, the first and second edge fields of view are located at the two extreme positions of the short side direction D2, respectively, and the light rays corresponding to these two edge fields of view have the greatest angular difference in the short side direction D2. When the light rays corresponding to these two edge fields of view are reflected by the first reflecting element 140 and can cross on the transmission path, the light rays corresponding to other fields of view located between these two edge fields of view will also converge near the crossing optical path region W. Thus, the light rays corresponding to all fields of view distributed along the short side direction D2 form a compact optical path envelope at the crossing optical path region W, thereby achieving a reduction in the size of the optical path envelope.

[0050] In some embodiments, the display screen 400 can correspond to a field of view of approximately 12° × 4°, and can form an eyebox area of ​​approximately 130mm × 150mm, covering approximately 99% of the eye ellipse. These parameters illustrate that, while meeting the display requirements of a large field of view and a large eyebox area, the optical path envelope size between the two reflective elements can still be controlled through the cross-optical path design between the first reflective element 140 and the second reflective element 160, thus reducing the difficulty of arranging the head-up display device 100 in the vehicle dashboard. It should be noted that the above values ​​can be adjusted according to different vehicle platforms, the position of the imaging window 200, the virtual image distance, and the type of the image generation unit 120, and are not intended to limit the overall applicability of the head-up display device 100 in this application.

[0051] In some embodiments, the approximately parallel optical path scheme can be compared with the cross-optical path scheme in the embodiments of this application. Under the same field of view, the same eyebox range, and the same imaging window conditions, the cross-optical path scheme can make the effective spot size on the first reflective element 140 smaller than the corresponding spot size in the approximately parallel optical path scheme, or make the effective reflection area size of the first reflective element 140 smaller than the corresponding effective reflection area size in the approximately parallel optical path scheme. Furthermore, the cross-optical path scheme can also reduce the maximum optical path envelope width or height between the first reflective element 140 and the second reflective element 160, or reduce the overall height or overall depth of the head-up display device 100.

[0052] In some embodiments, the first reflecting element 140 has a first effective reflecting region for reflecting image light S, and the second reflecting element 160 has a second effective reflecting region for reflecting image light S. The first effective reflecting region is the area covered by the reflected light spot formed by image light S on the first reflecting element 140, and the second effective reflecting region is the area covered by the reflected light spot formed by image light S on the second reflecting element 160. The size of the first effective reflecting region in the short-side direction D2 is denoted as B, and the size of the second effective reflecting region in the short-side direction D2 is denoted as A. At the intersecting optical path region W, the size of the optical path envelope formed by the rays corresponding to the multiple fields of view distributed along the short-side direction D2 in the short-side direction D2 is denoted as w. In some embodiments, the sizes w, A, and B can satisfy: (AB) / 15 ≤ w ≤ (AB) / 5. (Refer to...) Figure 8 It shows dimensions A, B, and dimension w at the cross-optical path region W.

[0053] The optical path envelope refers to the outer contour of the spatial range occupied by all light rays corresponding to the fields of view at a given cross-section. The size of the optical path envelope can be understood as the maximum span of the optical path envelope in a specific direction (e.g., the dimension corresponding to the shorter side direction D2) at that cross-section. At the intersecting optical path region W, the size of the optical path envelope reaches or is close to its minimum value because light rays from different fields of view intersect and converge. For example, in conjunction with a reference... Figure 2 It clearly shows the optical path envelope of the cross optical path region W.

[0054] The value of dimension w can be determined based on the specific design requirements of the head-up display device 100. It is understood that when w approaches (AB) / 5, the optical path envelope at the cross-optical path region W is relatively wide in the short-side direction D2, and the convergence of light rays corresponding to different fields of view near the cross-optical path is relatively low, which helps to reduce the processing accuracy requirements for the first and second reflective surface profiles. When w approaches (AB) / 15, the optical path envelope at the cross-optical path region W is narrower in the short-side direction D2, and the light rays corresponding to different fields of view are highly converged, which helps to further narrow the optical path envelope between the two reflective elements and reduce the dimension B of the first reflective element 140 in the short-side direction D2. By keeping w within the above range, a balance can be achieved between the narrowing of the optical path envelope and imaging quality, processing, and assembly difficulty.

[0055] In some embodiments, the size of the optical path envelope at the intersecting optical path region W can be controlled within a small range, for example, close to the beam size corresponding to a single field of view, thereby minimizing the space occupied by the optical path near the intersecting region W. By ensuring that the size w of the optical path envelope at the intersecting optical path region W in the short side direction D2 satisfies the above relationship, it can be ensured that the optical path design of the head-up display device 100 meets the requirements for compact arrangement.

[0056] Reference Figure 2 The bending fit relationship between the first and second reflective surface profiles is explained.

[0057] In some embodiments, the first reflective surface of the first reflective element 140 has a first surface section 142 corresponding to the short side direction D2, and the second reflective surface of the second reflective element 160 has a second surface section 162 corresponding to the short side direction D2.

[0058] The surface profile section referred to here is the cross-section of the reflective surface profile along the plane corresponding to the short side direction D2. Specifically, the first surface profile section 142 is the contour curve of the reflective surface of the first reflective element 140 in the section corresponding to the short side direction D2, and the second surface profile section 162 is the contour curve of the reflective surface of the second reflective element 160 in the section corresponding to the short side direction D2.

[0059] In the above embodiments, the first reflective surface profile has a first curvature within the first surface profile section 142, and the second reflective surface profile has a second curvature within the second surface profile section 162.

[0060] The curvature is used to characterize the degree of curvature of the reflective surface within the corresponding cross-section. In the embodiments of this application, the curvature is the ratio of the maximum sag of the curve of the cross-section relative to its chord to the corresponding dimension of the reflective element in the short-side direction D2. Specifically, the maximum sag of the curve of the first cross-section 142 relative to its chord is denoted as h1, and the maximum sag of the curve of the second cross-section 162 relative to its chord is denoted as h2; the first curvature is the ratio of h1 to the dimension B of the first effective reflective area in the short-side direction D2, i.e., h1 / B, and the second curvature is the ratio of h2 to the dimension A of the second effective reflective area in the short-side direction D2, i.e., h2 / A. (Refer to...) Figure 9 It shows the sagitta h1 and h2, as well as dimensions A and B, to define the first and second curvature. The greater the curvature, the greater the degree of curvature of the reflecting surface within that cross-section, and the stronger the converging effect on light.

[0061] In some embodiments, the first bending amount can be between 0.055 and 0.075, the second bending amount can be between 0.045 and 0.065, and the ratio of the first bending amount to the second bending amount can be between 0.8 and 1.2.

[0062] Combined with reference Figure 3 It illustrates how the cross-optical path region W is adjusted by adjusting the first curvature of the first reflective surface profile of the first reflective element 140 within the first surface profile section 142, and the second curvature of the second reflective surface profile of the second reflective element 160 within the second surface profile section 162. The first curvature state of the first reflective element 140 and the second reflective element 160 is shown in solid lines, and the second curvature state is shown in dashed lines.

[0063] The values ​​and ratio of the first and second curvature amounts affect the formation position, crossing angle, and degree of contraction of the optical path envelope in the cross-path region W. By controlling the first curvature amount between 0.055 and 0.075, the converging effect of the first reflective element 140 on the image light S can be ensured to be at an appropriate level, allowing light rays from different fields of view to cross during transmission without causing a decrease in image quality due to excessive convergence. Similarly, by controlling the second curvature amount between 0.045 and 0.065, the second reflective element 160 can ensure that the light rays that diverge again after crossing can be reflected to the imaging window 200 in an appropriate manner. A ratio of the first to second curvature amounts between 0.8 and 1.2 ensures the coordinated relationship between the surface shapes of the first and second reflective elements 140 and 160, enabling the entire optical system to meet the comprehensive requirements of image quality, field of view, and eyebox range while realizing the cross-path.

[0064] In some implementations, the values ​​of the first bending amount, the second bending amount, and the ratio of the first bending amount to the second bending amount can be determined based on the field of view, eyebox range, imaging window position, virtual image distance, distance between the first reflective element 140 and the second reflective element 160, image generation unit 120 position, and available space within the vehicle dashboard.

[0065] If the first or second curvature is too small, the convergence effect of the first and second reflective surface profiles on light rays from different fields of view will be insufficient. Light rays corresponding to different fields of view may still propagate approximately parallel or only slightly converge between the first reflective element 140 and the second reflective element 160, resulting in an indistinct cross-path region W, insufficient narrowing of the optical path envelope, and difficulty in effectively reducing the size of the effective reflection area of ​​the first reflective element 140. If the first or second curvature is too large, light rays corresponding to different fields of view may be excessively converged or excessively spread, causing the position of the cross-path region W to deviate from the expected spatial range, or resulting in uneven distribution of the light spot reaching the second reflective element 160. Excessive curvature may also increase the difficulty of aberration correction, reduce image quality, increase the manufacturing difficulty of reflective elements, and increase the impact of assembly deviations on the imaging effect.

[0066] The ratio of the first bending amount to the second bending amount is used to characterize the fit between the first reflective element 140 and the second reflective element 160 when forming the intersecting optical path region W. When this ratio is between 0.8 and 1.2, the first reflective element 140 and the second reflective element 160 can jointly form the expected intersecting optical path region W, and the position, intersection angle, and optical path envelope size of the intersecting optical path region W meet the design requirements. When this ratio deviates from 0.8 to 1.2, the surface fit between the first reflective element 140 and the second reflective element 160 may be unbalanced, leading to a decrease in optical path envelope compression effect, imaging quality, or assembly stability.

[0067] Still refer to Figure 3 In some embodiments, the cross optical path region W is located within a preset space between the first reflective element 140 and the second reflective element 160.

[0068] The preset spatial range is a pre-defined area within the optical path transmission space between the first reflective element 140 and the second reflective element 160. The position of the intersecting optical path region W has a significant impact on the optical path envelope size and overall layout of the head-up display device 100. (Refer to...) Figure 10 In some embodiments, the optical path length between the first reflecting element 140 and the second reflecting element 160 along the propagation path of the image light S is denoted as C, and the optical path length between the intersecting optical path region W and the first reflecting element 140 is denoted as F. Here, the optical path length is the product of the corresponding physical length and the refractive index of the medium through which the light passes. In some embodiments, the position of the intersecting optical path region W can satisfy: 0.25 ≤ F / C ≤ 0.35.

[0069] In some implementations, the position of the intersecting optical path region W can be determined based on multiple main rays, edge rays, or multiple sampled rays. For example, in a coordinate system including the effective reflection area of ​​the first reflective element 140, the effective reflection area of ​​the second reflective element 160, and the optical path transmission space between them, the position region where the optical path envelope size formed by rays corresponding to multiple fields distributed along the short side direction D2 reaches a minimum or local minimum can be determined, and this position region is taken as the intersecting optical path region W.

[0070] The position of the intersecting optical path region W affects the effective reflection area size on the first reflective element 140, the light spot distribution on the second reflective element 160, and the space occupied between the two reflective elements. When the intersecting optical path region W is set within a preset space between the first reflective element 140 and the second reflective element 160, different field-of-view rays can undergo appropriate convergence and expansion processes between the two reflective elements, thereby narrowing the optical path envelope between the two reflective elements while ensuring that the light reaching the second reflective element 160 still has a suitable spatial distribution.

[0071] Understandably, if the intersecting optical path region W is too close to the first reflecting element 140, light rays from different fields of view will intersect quickly after leaving the first reflecting element 140. The intersecting light rays will then experience a longer divergence path before reaching the second reflecting element 160, potentially resulting in a still large optical path envelope upon reaching the second reflecting element 160. This weakens the effect of the intersecting optical path design on optical path envelope contraction. Conversely, if the intersecting optical path region W is too close to the second reflecting element 160, light rays from different fields of view may still occupy a large space on the transmission path from the first reflecting element 140 to the intersecting optical path region W, which is also detrimental to optical path compactness. Therefore, controlling the position of the intersecting optical path region W within a preset spatial range helps to achieve overall optimization of the optical path envelope size throughout the entire transmission path between the first reflecting element 140 and the second reflecting element 160.

[0072] In some embodiments, the preset spatial range can be set to the vicinity of the intermediate region between the first reflective element 140 and the second reflective element 160, or to a region biased towards the first reflective element 140. The specific preset spatial range can be determined based on factors such as the optical path design parameters of the head-up display device 100, the available space in the vehicle's dashboard, and imaging quality requirements.

[0073] Continue to refer to Figure 3 In some embodiments, the distance from the cross optical path region W to the effective reflection region of the first reflective element 140 is less than the distance from the cross optical path region W to the effective reflection region of the second reflective element 160.

[0074] The effective reflection area refers to the region on the reflective element that actually participates in reflecting the image light S. The effective reflection area of ​​the first reflective element 140 is the area covered by the reflected light spot formed by the image light S on the first reflective element 140, and the effective reflection area of ​​the second reflective element 160 is the area covered by the reflected light spot formed by the image light S on the second reflective element 160. The distance from the intersecting optical path region W to the effective reflection area can be understood as the optical path distance or spatial distance between the center position of the intersecting optical path region W and the center position of the effective reflection area of ​​the corresponding reflective element.

[0075] In the head-up display device 100, the second reflective element 160 typically has a larger effective reflection area than the first reflective element 140 because the second reflective element 160 needs to reflect the image light S to the imaging window 200 with a larger coverage area to meet the display requirements of a large field of view and a large eyebox. If the cross-optical path region W is close to the second reflective element 160, the light rays from different fields of view will only travel a short divergence path to reach the second reflective element 160 after crossing. The optical path envelope when reaching the second reflective element 160 may not be fully expanded, which may affect the effective coverage and reflection of light rays from different fields of view by the second reflective element 160.

[0076] Conversely, by positioning the cross-optical path region W closer to the first reflective element 140, light rays from different fields of view cross more quickly after being reflected by the first reflective element 140. They then gradually diverge along the longer transmission path from the cross-optical path region W to the second reflective element 160, forming an appropriately sized optical path envelope upon reaching the second reflective element 160. This design ensures that the optical path envelope effectively contracts near the cross-optical region W while also guaranteeing a suitable spatial distribution of light rays reaching the second reflective element 160. This facilitates the second reflective element 160 reflecting the image light S to the imaging window 200 in the correct direction and angle.

[0077] Furthermore, the proximity of the intersecting optical path region W to the first reflective element 140 helps to reduce the size of the effective reflection area of ​​the first reflective element 140. Since light rays from different fields of view intersect quickly after leaving the first reflective element 140, the spacing between the reflected light spots on the first reflective element 140 is smaller, thus making the effective reflection area of ​​the first reflective element 140 more compact. This further contributes to reducing the physical size of the first reflective element 140, thereby facilitating the overall compact design of the head-up display device 100.

[0078] Reference Figure 4 In some embodiments, the second reflective element 160 is set in a preset mounting posture, which is configured to minimize the minimum distance between the effective reflection area of ​​the first reflective element 140 and the light emission envelope of the second reflective element 160, thereby making the optical path layout of the head-up display device 100 compact while avoiding optical path interference and mechanical structure interference.

[0079] The light emission envelope refers to the outer contour of the image light S reflected by the reflecting element in space. The effective reflection area of ​​the first reflecting element 140 is the region on the first reflecting element 140 that actually participates in reflecting the image light S. The light emission envelope of the second reflecting element 160 is the outer contour of the image light S formed when it propagates in space after being reflected by the second reflecting element 160. The minimum distance between the effective reflection area of ​​the first reflecting element 140 and the light emission envelope of the second reflecting element 160 refers to the distance between the closest points in space between these two areas.

[0080] In some embodiments, the preset mounting posture of the second reflective element 160 may include the mounting angle, tilt angle, reference angle, or rotation angle of the second reflective element 160 relative to the device housing, image generation unit 120, first reflective element 140, or imaging window 200. By adjusting the preset mounting posture of the second reflective element 160, the light rays corresponding to different positions in the eye box region 300 can be translated as a whole, thereby adjusting the position of the cross-optical path region W between the first reflective element 140 and the second reflective element 160, or adjusting the position and size of the effective reflective area on the first reflective element 140.

[0081] Understandably, the minimum distance between the effective reflection area of ​​the first reflective element 140 and the light emission envelope of the second reflective element 160 reflects the spatial compactness of the optical path of the head-up display device 100 near the second reflective element 160. If this minimum distance is too small, the light reflected by the first reflective element 140 and the second reflective element 160 will be too close in space, potentially leading to optical path interference or mechanical interference. If this minimum distance is too large, it means that there is a large spatial gap between the light reflected by the second reflective element 160 and the first reflective element 140, and this space is not effectively utilized, which may increase the overall size of the head-up display device 100.

[0082] By configuring the mounting orientation of the second reflective element 160 to minimize the aforementioned minimum distance while avoiding optical path interference and mechanical structure interference, the optical path layout of the head-up display device 100 can be made as compact as possible. Furthermore, since the effective reflection area of ​​the first reflective element 140 can be closer to the light emission envelope of the second reflective element 160, the physical size of the first reflective element 140 can be further reduced, thereby further reducing the overall volume of the head-up display device 100.

[0083] In some embodiments, the ratio of the size B of the first effective reflective region in the short side direction D2 to the size A of the second effective reflective region in the short side direction D2 can be between 0.41 and 0.65.

[0084] The field-of-view expansion dimension refers to the direction corresponding to the short side direction D2 of the display screen 400 on the effective reflective area of ​​the first reflective element 140. Since the short side direction D2 of the display screen 400 usually corresponds to the vertical direction, the field-of-view expansion dimension can be understood as the vertical extent of the effective reflective area of ​​the first reflective element 140. The size of the effective reflective area in the field-of-view expansion dimension is the maximum span of that area in the vertical direction.

[0085] In the embodiments of this application, through the cross-optical path design, light rays from different fields of view begin to converge after being reflected by the first reflective element 140, resulting in a smaller spacing between the reflected light spots on the first reflective element 140. Consequently, the size B of the first effective reflection area in the short-side direction D2 can be correspondingly reduced, allowing the ratio of size B to size A to be controlled within the aforementioned range.

[0086] It is understandable that the size A of the second effective reflective area in the short-side direction D2 is mainly determined by factors such as the field of view, eyebox range, imaging distance, and the shape of the imaging window 200, and is relatively fixed under a given design. Therefore, by controlling the ratio of size B to size A within the above range, the size B of the first effective reflective area in the short-side direction D2 can be reduced accordingly, thereby ensuring that the size of the first reflective element 140 meets the requirements of compact design. It is understandable that when this ratio is smaller, the size of the first reflective element 140 is relatively smaller, which is beneficial for compactness; when this ratio is larger, the convergence of light rays corresponding to different fields of view is relatively lower, which is beneficial for maintaining imaging quality and assembly margin.

[0087] In some embodiments, the first effective reflection area can be determined by the light spot envelope of the image light S corresponding to different fields of view on the first reflective element 140. By controlling the ratio of size B to size A within the above range, the first reflective element 140 can be made smaller, thereby reducing the space occupied by the first reflective element 140 itself and further reducing the overall space occupied by the head-up display device 100.

[0088] Reference Figure 5 The dustproof component 180 is described below.

[0089] The head-up display device 100 may also include a dustproof component 180. The dustproof component 180 may be disposed on the light emission path of the head-up display device 100 or at the dustproof opening of the head-up display device 100.

[0090] like Figure 5 As shown, the dustproof component 180 is disposed on the light-emitting path between the second reflective element 160 and the imaging window 200. The dustproof component 180 may also be disposed at a dustproof opening in the housing of the head-up display device 100. Here, the dustproof opening is an opening or window in the head-up display device 100 for the image light S to be emitted.

[0091] The dustproof component 180 allows visible light to pass through while blocking or attenuating near-infrared light. Thus, the dustproof component 180 reduces the entry of dust, foreign objects, or other external contaminants into the head-up display device 100, decreasing the likelihood of dust adhering to the first reflective element 140, the second reflective element 160, or the image generating unit 120. Furthermore, the dustproof component 180 also blocks or attenuates the near-infrared component of external light entering the head-up display device 100 from the imaging window 200 side. Since the near-infrared component of sunlight typically has a high thermal effect, especially for head-up displays with a large field of view that may receive more external light, reducing the entry of near-infrared light into the head-up display device 100 helps reduce the possibility of localized overheating of internal optical components or the image generating unit 120.

[0092] The dustproof component 180 may include a transparent substrate and an infrared blocking layer disposed on the transparent substrate. The transparent substrate may be glass, a transparent polymer, or other transparent materials that meet automotive-grade environmental requirements. The infrared blocking layer may be a coating layer, a plating layer, or other functional layers with near-infrared blocking capability. The infrared blocking layer may be disposed on the side of the transparent substrate facing the imaging window 200, or on the side of the transparent substrate facing the interior of the head-up display device 100, or on both sides of the transparent substrate or between internal layers.

[0093] The dustproof component 180 has a transmittance of greater than or equal to 90% in the visible light band and a cutoff rate of greater than or equal to 85% in the near-infrared band. Here, the visible light band can be determined based on the visible display band of the image light S of the head-up display device 100, for example, a band range of approximately 380 nm to 780 nm. The near-infrared band can be determined based on the band of sunlight that has a significant impact on the internal temperature rise of the head-up display device 100, for example, a band range of approximately 780 nm to 1100 nm, or other near-infrared band ranges can be adopted according to the spectral design of the specific project. The transmittance can be, for example, the average transmittance of the dustproof component 180 in the visible light band. The cutoff rate can be, for example, the average cutoff rate of the dustproof component 180 in the near-infrared band.

[0094] By ensuring that the dustproof component 180 has high transmittance in the visible light band, the image light S emitted from the head-up display device 100 can pass through the dustproof component 180 with low loss and be directed towards the imaging window 200, thereby helping to maintain display brightness. By ensuring that the dustproof component 180 has high cutoff in the near-infrared band, the near-infrared components in external light can be attenuated before entering the head-up display device 100, thereby reducing the possibility of heat absorption by the image generation unit 120, the first reflective element 140, the second reflective element 160, or other internal optical components.

[0095] Below, refer to Figure 6 and Figure 7 The transmissive imaging element 124 in the image generation unit 120 will be described.

[0096] like Figure 6 As shown, external light rays L can flow back to the image generation unit 120 along the opposite path of image light S. Here, external light rays L can include sunlight or other strong light from outside the vehicle or outside the imaging window 200. External light rays L can enter the head-up display device 100 through the imaging window 200, and then propagate in the opposite direction to the image generation unit 120 via the second reflective element 160 and the first reflective element 140. For the head-up display device 100 with a large field of view and a large eye box, external light rays L may form a locally strong illumination area in or near the image generation unit 120. If the components in the image generation unit 120 used to receive image light or form an image have a high absorptivity, the energy of external light rays L may be absorbed at that location and converted into heat, thereby increasing the local temperature rise.

[0097] like Figure 7 As shown, the image generation unit 120 may include a projection optical engine 122 and a transmissive imaging element 124 disposed on the light-emitting side of the projection optical engine 122. The projection optical engine 122 can be used to generate and project image light S. The transmissive imaging element 124 can receive the image light S projected by the projection optical engine 122. The transmissive imaging element 124 may be a transmissive screen, a light-transmitting imaging plate, a diffuse imaging element, a light-transmitting substrate, or other optical element capable of receiving the image light S projected by the projection optical engine 122 and allowing at least part of the light to pass through.

[0098] When external light L flows back along the opposite path of image light S to the image generation unit 120, the transmittance of the external light L reaching the transmissive imaging element 124 can be greater than its absorptivity. Here, transmittance can be the proportion of energy in the external light L that passes through the transmissive imaging element 124, and absorptivity can be the proportion of energy in the external light L that is absorbed by the transmissive imaging element 124. By making the transmittance greater than the absorptivity, more external light L can pass through the transmissive imaging element 124 instead of being absorbed and converted into heat at the transmissive imaging element 124. This reduces the risk of localized temperature rise and thermal failure of the transmissive imaging element 124.

[0099] In some examples, conventional liquid crystal displays (LCDs) may have a transmittance of approximately 5% to 8% and an absorptivity of approximately 94% for backflowed external light L. In contrast, the transmissive imaging element 124 may have a transmittance of approximately 90% or more for backflowed external light L and an absorptivity of approximately 6%. In some embodiments, the transmissive imaging element 124 may have a higher temperature resistance than conventional LCDs. For example, conventional thin-film transistor liquid crystal displays may fail at temperatures above approximately 100°C to 105°C, while the transmissive imaging element 124 may be formed of a heat-resistant transparent material and can withstand higher temperatures, such as approximately 300°C.

[0100] It is understandable that the transmittance of the transmissive imaging element 124 to the external light L is greater than its absorptivity, and it is not required that the external light L will not undergo any scattering, reflection, or loss. The transmissive imaging element 124 can allow a high proportion of the backflowing external light L to pass through while maintaining the imaging or diffusion function of the image light S projected by the projection optical engine 122. After passing through the transmissive imaging element 124, the external light L can be further diverged within the image generation unit 120 or dispersed by subsequent structures, thereby reducing its local heat concentration at the transmissive imaging element 124.

[0101] The transmissive imaging element 124 may include a substrate made of a light-transmitting material. The light-transmitting material may include at least one of glass or a transparent polymer. By configuring the substrate of the transmissive imaging element 124 as a light-transmitting material, the transmittance of external light L by the transmissive imaging element 124 can be improved. Glass materials can have high transmittance, good temperature resistance, and good dimensional stability. Transparent polymer materials can have low weight and good formability.

[0102] The projection optical engine 122 may include at least one of a silicon-based liquid crystal optical engine, a digital light processing optical engine, a micro light-emitting diode optical engine, or a laser scanning optical engine. The silicon-based liquid crystal optical engine, digital light processing optical engine, micro light-emitting diode optical engine, and laser scanning optical engine can all generate and project image light S according to image display requirements.

[0103] Combination Figures 5 to 7It is understood that the dustproof component 180 and the transmissive imaging component 124 can jointly form a thermal protection path against backflow of external light L. The dustproof component 180 is located at the light-emitting path or dustproof opening of the head-up display device 100, and can cut off or attenuate near-infrared light at the front end of the external light L entering the head-up display device 100. The transmissive imaging component 124 is located inside the image generation unit 120 or on the light-emitting side of the image generation unit 120, and can allow a larger proportion of the remaining external light L to pass through the transmissive imaging component 124 when it reaches the image generation unit 120, rather than being absorbed and converted into heat at the transmissive imaging component 124. Thus, the dustproof component 180 and the transmissive imaging component 124 reduce the risk of localized temperature rise from the front end of the external light L entry path and the image generation unit 120 side, respectively.

[0104] The dustproof component 180 primarily reduces the near-infrared energy in the backflow of external light L, while the transmissive imaging component 124 primarily reduces the heat accumulation from the absorption of remaining external light L on the image generation unit 120 side. Together, they reduce the risk of localized thermal failure of the image generation unit 120, the transmissive imaging component 124, or their surrounding structures, even in head-up display scenarios with a large field of view, a large eyebox range, or a large imaging distance.

[0105] The aforementioned features can be combined according to specific product needs. For example, the head-up display device 100 can use only the cross-optical path region W to compress the optical path envelope and reduce the size of the first reflective element 140. The head-up display device 100 can also further employ a dustproof component 180 in addition to the cross-optical path region W to reduce the near-infrared energy in external light L from entering the head-up display device 100. The head-up display device 100 can also further employ a transmissive imaging component 124 in addition to the cross-optical path region W and the dustproof component 180 to reduce the absorption of external light L at the image generation unit 120. Through the combination of these solutions, the head-up display device 100 can achieve a larger display range and eye box range while simultaneously considering internal space arrangement and thermal risk control caused by external light backflow.

[0106] According to the embodiments of this application, by configuring and arranging the reflective surfaces of the first reflective element 140 and the second reflective element 160 relative to each other, light rays corresponding to different fields of view can be reflected by the first reflective element 140 and form a cross-optical path region W between the first reflective element 140 and the second reflective element 160. That is, the second reflective element 160 is disposed on the reflected optical path of the first reflective element 140. After being reflected by the first reflective element 140, the image light propagates between the first reflective element 140 and the second reflective element 160 through the cross-optical path region W to the second reflective element 160, and is then reflected by the second reflective element 160 to the imaging window 200. Thus, the optical path envelopes formed by light rays from different fields of view can be narrowed near the cross-optical path region W, thereby reducing the space occupied between the two reflective elements.

[0107] Furthermore, since the cross-optical path region W causes the light rays corresponding to different fields of view to converge and cross between the two reflective elements, the effective reflection area on the first reflective element 140 can be reduced accordingly, thereby allowing the first reflective element 140 to adopt a smaller size, or to obtain a larger assembly margin under the same size.

[0108] Furthermore, by controlling the bending amount of the first reflective element 140, the bending amount of the second reflective element 160, the proportional relationship between the two, the position of the cross optical path region W, and the mounting posture of the second reflective element 160, a balance can be achieved between optical path envelope compression, imaging quality, processing difficulty of reflective elements, and assembly stability.

[0109] Furthermore, by providing a dustproof component 180 that allows visible light to pass through and blocks or attenuates near-infrared light at the light exit path or dustproof opening of the head-up display device 100, and by providing a low-absorption transmissive imaging component 124 in the image generation unit 120, the risk of local temperature rise caused by backflow of external light L can be reduced from the front end of the external light L entry path and the side of the image generation unit 120.

[0110] Although this application has been described with reference to exemplary embodiments, it should be understood that this application is not limited to the specific embodiments described and shown herein. Various changes can be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of this application.

[0111] The features mentioned and / or shown in the above description of exemplary embodiments of this application may be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. Such combinations or substitutions should also be considered as including within the scope of protection of this application.

Claims

1. A head-up display device, characterized by comprising: include: An image generation unit emits image light, the image light comprising light rays corresponding to different fields of view; A first reflective element is disposed on the light-emitting side of the image generating unit and has a first reflective surface shape to receive and reflect the image light; as well as A second reflective element is disposed in the reflected light path of the first reflective element and has a second reflective surface shape to receive the image light reflected by the first reflective element and reflect the image light reflected by the first reflective element to the imaging window. In this process, the light rays corresponding to different fields of view in the image light are reflected by the first reflective element and then cross each other between the first reflective element and the second reflective element to form a cross-optical path region. The image light then propagates to the second reflective element through the cross-optical path region.

2. The head-up display device according to claim 1, characterized by The image light corresponds to a display screen with a long side direction and a short side direction. The different fields of view include multiple fields of view distributed along the short side direction. The intersecting optical path region is formed by the cross-section of light rays corresponding to the multiple fields of view distributed along the short side direction after being reflected by the first reflective element.

3. The head-up display device according to claim 2, characterized by The plurality of fields of view distributed along the short side direction include a first edge field of view and a second edge field of view located on opposite sides of the short side direction. The light rays in the image light corresponding to the first edge field of view and the light rays corresponding to the second edge field of view are reflected by the first reflective element and then cross between the first reflective element and the second reflective element.

4. The head-up display apparatus according to claim 2, characterized by The first reflective element has a first effective reflective area for reflecting the image light, and the second reflective element has a second effective reflective area for reflecting the image light. At the cross-optical path region, the optical path envelope formed by the rays corresponding to the multiple fields of view distributed along the short side direction has a size w in the short side direction, the size of the first effective reflection region in the short side direction is B, and the size of the second effective reflection region in the short side direction is A, and satisfies: (AB) / 15≤w≤(AB) / 5.

5. The head-up display apparatus according to claim 2, characterized by The first reflective surface profile has a first cross-section corresponding to the short side direction, and the second reflective surface profile has a second cross-section corresponding to the short side direction. The first reflective surface profile has a first curvature within the first surface profile cross-section, and the second reflective surface profile has a second curvature within the second surface profile cross-section. The first curvature is between 0.055 and 0.075, the second curvature is between 0.045 and 0.065, and the ratio of the first curvature to the second curvature is between 0.8 and 1.

2.

6. The head-up display apparatus according to claim 2, characterized by The distance from the cross-optical path region to the effective reflection region of the first reflective element is less than the distance from the cross-optical path region to the effective reflection region of the second reflective element.

7. The head-up display device according to claim 6, characterized by Along the propagation path of the image light, the optical path between the first reflective element and the second reflective element is C, the optical path between the cross-optical path region and the first reflective element is F, and the position of the cross-optical path region satisfies: 0.25≤F / C≤0.

35.

8. The head-up display apparatus according to claim 2, characterized by The first reflective element has a first effective reflective area for reflecting the image light, and the second reflective element has a second effective reflective area for reflecting the image light. The first effective reflective area has a size of B in the short side direction, and the second effective reflective area has a size of A in the short side direction. The ratio of B to A is between 0.41 and 0.

65.

9. The head-up display apparatus according to claim 1, characterized by It also includes a dustproof component, which is disposed on the light path of the head-up display device or at the dustproof opening of the head-up display device, and is configured to allow visible light to pass through while blocking or attenuating near-infrared light.

10. The head-up display device according to claim 1, characterized in that, The image generation unit includes a projection optical engine and a transmissive imaging element disposed on the light-emitting side of the projection optical engine. The transmissive imaging element is configured to receive image light projected by the projection optical engine, and when external light rays flow back into the image generation unit along the opposite path of the image light, the transmittance of the external light rays reaching the transmissive imaging element is greater than its absorptivity.

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