Head-up display system and design method thereof

Abstract

A head-up display system (1) and a method for designing the same, the head-up display system (1) comprising a laminated glass (10) having at least one projection display area (11), each projection display area (11) having a wedge-shaped cross-sectional shape in which the thickness of an upper side edge (111) is greater than that of a lower side edge (112) when the laminated glass (10) is mounted on a vehicle, the wedge angle of the section (113) is continuously reduced from the lower side edge (112) to the upper side edge (111); the projection assembly (20) comprises at least one projection light source (21), and projection light emitted by the projection light source (21) enters the projection display area (11) to form a projection image (114) with a virtual image surface (TB10); and an eye box (EB1) having an eye box surface (EB10) through which the projection image (114) is observed through the projection display area (11). The virtual image surface (TB10) comprises a plurality of sub-virtual image surfaces (TB11), each sub-virtual image surface (TB11) comprises an upper virtual image surface (TB112) and a lower virtual image surface (TB113), the upper virtual image surface (TB112) and / or the lower virtual image surface (TB113) of at least one sub-virtual image surface (TB11) are / is inclined towards the direction of observing the corresponding sub-virtual image surface (TB11) from the sub-eye box surface (EB11), and the front inclination angle of the upper virtual image surface and / or the lower virtual image surface is greater than or equal to 45 degrees. And the riding experience is improved.

Description

Head-up display system and design method of head-up display system Technical Field

[0001] The present application relates to the automotive field, and in particular to a head-up display system and a design method for a head-up display system. Background Art

[0002] With the development of intelligent vehicles, head-up display (HUD) systems are increasingly being used in vehicles. These systems display images, such as driving information, in real time on the front windshield. Windshields are typically laminated glass. Considering the complex operating conditions of real-world vehicles, different drivers have different seating positions, and the human eye's viewing angle is an envelope. Laminated glass with a fixed wedge angle cannot effectively address the problem of secondary images at different viewing angles. Generally, different wedge angles can be set for different projection display areas on the laminated glass, i.e., laminated glass with a variable wedge angle, to reduce secondary images. The virtual image plane of a traditional HUD image is designed to be perpendicular to the ground and facing the driver. This virtual image plane results in an overly discrete distribution of the theoretical wedge angles required to eliminate secondary images in different projection display areas of the laminated glass. Furthermore, augmented reality head-up displays (AR-HUDs) will cover more lanes and provide richer navigation warnings and other information. Their field of view (FOV) will expand, for example to 10°×5° or even 20°×5°, increasing the projection display area. This further exacerbates the overly discrete distribution of the theoretical wedge angles required to eliminate secondary images in the projection display area. Consequently, even with a projection display area with a variable wedge angle, the secondary image problem cannot be effectively resolved, thus affecting the driving experience.

[0003] Summary of the Invention

[0004] In a first aspect, the present application provides a head-up display system, comprising:

[0005] Laminated glass, the laminated glass having at least one projection display area, each of the projection display areas having a wedge-shaped cross-section in which the thickness of the upper side of the laminated glass is greater than that of the lower side when the laminated glass is installed in a vehicle, and having a wedge angle that continuously decreases from the lower side to the upper side;

[0006] a projection assembly, the projection assembly comprising at least one projection light source capable of projecting onto the at least one projection display area, wherein projection light emitted by the projection light source is incident on the projection display area to form a projection image, and the projection image has a virtual image surface; and

[0007] an eye box, the eye box having an eye box surface for observing the projection image through the projection display area;

[0008] The eye box surface includes a plurality of sub-eye box surfaces, the virtual image surface includes a plurality of sub-virtual image surfaces corresponding to the plurality of sub-eye box surfaces, each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface, and the upper virtual image surface and / or the lower virtual image surface of at least one of the sub-virtual image surfaces are inclined toward the direction of observing the corresponding sub-virtual image surface from the sub-eye box surface, and the forward tilt angle thereof is greater than or equal to 45°.

[0009] In a second aspect, the present application provides a design method for a head-up display system, the design method for a head-up display system comprising:

[0010] Providing a projection assembly and laminated glass, wherein projection light emitted by the projection assembly is incident on at least one projection display area on the laminated glass;

[0011] The eyebox surface located inside the vehicle is designed based on the observer inside the vehicle;

[0012] The virtual image plane is designed to be inclined toward the direction of observing the corresponding sub-virtual image plane from the sub-eye box surface according to the projection image observed by the observer in the car through each projection display area;

[0013] The eye box surface includes a plurality of sub-eye box surfaces, and the virtual image surface includes a plurality of sub-virtual image surfaces, wherein each sub-virtual image surface corresponds to a sub-eye box surface, and each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface. The upper virtual image surface and / or the lower virtual image surface of at least one of the sub-virtual image surfaces are inclined toward a direction in which the corresponding sub-virtual image surface is observed from the sub-eye box surface, and the forward tilt angle thereof is greater than or equal to 45°.

[0014] An observation lattice is selected on each sub-eye box surface, and a virtual image lattice is selected on each sub-virtual image surface, wherein a line connecting points in the observation lattice and points in the virtual image lattice passes through a corresponding projection display area, and an intersection of the line and the projection display area is an incident point;

[0015] Calculating multiple theoretical wedge angle values ​​of the laminated glass when the projection image at the corresponding incident point position has no secondary image based on the projection assembly, the laminated glass, and the multiple connecting lines;

[0016] According to the plurality of theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass of the laminated glass corresponding to each theoretical wedge angle value, fitting is performed to obtain a first theoretical wedge angle fitting line representing the wedge angle as the distance from the incident point to the bottom edge of the glass is varied; and

[0017] The wedge angle value of the laminated glass in the corresponding projection display area is determined according to the first theoretical wedge angle fitting line. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic structural diagram of a head-up display system provided in one embodiment of the present application;

[0019] FIG2 is a schematic diagram of an optical path of a head-up display system provided in the embodiment of FIG1 ;

[0020] FIG3 is a schematic diagram of a head-up display system provided in the embodiment of FIG1 installed in a vehicle;

[0021] FIG4 is a schematic diagram showing the tilted upper and lower virtual image surfaces of the head-up display system provided by the embodiment of FIG1 ;

[0022] FIG5 is a schematic diagram of a tilted virtual image of a head-up display system provided by the embodiment of FIG1 ;

[0023] FIG6 is a schematic diagram showing the distribution of multiple theoretical wedge angle values ​​required for eliminating secondary images in the head-up display system provided by the embodiment of FIG1 ;

[0024] FIG7 is a simulation diagram showing the relationship between the front inclination angle of the virtual image and VID1 / VID2 of the head-up display system provided in the embodiment of FIG1 ;

[0025] FIG8 is a schematic diagram of fitting lines of wedge angles within a segment of the head-up display system provided in the embodiment of FIG1 ;

[0026] FIG9 is a schematic structural diagram of a head-up display system provided in another embodiment of the present application;

[0027] FIG10 is a schematic diagram of the optical path of the head-up display system provided in the embodiment of FIG9 ;

[0028] FIG11 is a schematic structural diagram of a head-up display system provided in another embodiment of the present application;

[0029] FIG12 is a schematic structural diagram of the laminated glass of the head-up display system provided in the embodiment of FIG1 ;

[0030] FIG13 is a flow chart of a design method for a head-up display system provided in an embodiment of the present application;

[0031] FIG14 is a schematic diagram of an optical path of a design method for a head-up display system provided by the embodiment of FIG13 ;

[0032] FIG15 is a schematic diagram of a first theoretical wedge angle fitting line of the design method of the head-up display system provided by the embodiment of FIG13 ;

[0033] FIG16 is a schematic diagram illustrating adjustment of two adjacent first theoretical wedge angle fitting lines of the same type of projection display area in the design method of the head-up display system provided in the embodiment of FIG13 ;

[0034] FIG17 is a schematic diagram illustrating adjustment of two adjacent first theoretical wedge angle fitting lines for different types of projection display areas in the design method of the head-up display system provided in the embodiment of FIG13 ;

[0035] FIG18 is a schematic diagram of two adjacent first theoretical wedge angle fitting lines of different types of projection display areas after adjustment according to the design method of the head-up display system provided in the embodiment of FIG17 ;

[0036] FIG19 is a schematic diagram showing the design of an observation lattice and a virtual image lattice in a design method for a head-up display system according to an embodiment of the present application;

[0037] FIG20 is a scatter plot of theoretical wedge angle distribution values ​​when observing the sub-virtual image plane without a secondary image on the perpendicular bisector of the sub-eye box surface according to the design method of the head-up display system provided by the embodiment of FIG19 ;

[0038] FIG21 is a distribution profile diagram of theoretical wedge angle values ​​without secondary images when observing multiple sub-virtual image planes from multiple sub-eye box surfaces in the first and second embodiments of the design method for the head-up display system provided in FIG19 ;

[0039] FIG. 22 is a scatter diagram showing the distribution of theoretical wedge angle values ​​when observing multiple sub-virtual image planes without secondary images from multiple sub-eye box surfaces according to the first and second embodiments of the design method for the head-up display system provided in the embodiment of FIG. 19 .

[0040] Reference numerals: head-up display system 1; laminated glass 10; projection display area 11; upper side 111; lower side 112; segment 113; projection image 114; first projection display area 115; first projection image 1151; second projection display area 116; second projection image 1161; bottom edge 12 of glass; top edge 13 of glass; first transparent substrate 14; second transparent substrate 15; intermediate adhesive layer 16; projection assembly 20; projection light source 21; first projection light source 211; second projection light source 212; eye box EB1; eye box surface EB10; sub-eye box surface EB11; observation point matrix EB111; virtual image plane TB10; sub-virtual image plane TB11; upper virtual image plane TB112; lower virtual image plane TB113; virtual image point matrix TB111; actual wedge angle fitting line L0; first theoretical wedge angle fitting line L1; second theoretical wedge angle fitting line L2; third theoretical wedge angle fitting line L3. DETAILED DESCRIPTION

[0041] In a first aspect, the present application provides a head-up display system, comprising:

[0042] Laminated glass, the laminated glass having at least one projection display area, each of the projection display areas having a wedge-shaped cross-section in which the thickness of the upper side of the laminated glass is greater than that of the lower side when the laminated glass is installed in a vehicle, and having a wedge angle that continuously decreases from the lower side to the upper side;

[0043] a projection assembly, the projection assembly comprising at least one projection light source capable of projecting onto the at least one projection display area, wherein projection light emitted by the projection light source is incident on the projection display area to form a projection image, and the projection image has a virtual image surface;

[0044] and an eye box having an eye box surface for observing the projection image through the projection display area;

[0045] The eye box surface includes a plurality of sub-eye box surfaces, the virtual image surface includes a plurality of sub-virtual image surfaces corresponding to the plurality of sub-eye box surfaces, each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface, and the upper virtual image surface and / or the lower virtual image surface of at least one of the sub-virtual image surfaces are inclined toward the direction of observing the corresponding sub-virtual image surface from the sub-eye box surface, and the forward tilt angle thereof is greater than or equal to 45°.

[0046] The upper virtual image plane and / or the lower virtual image plane of at least one of the sub-virtual image planes are tilted toward a direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane, and a forward tilt angle thereof is greater than or equal to 75°.

[0047] Wherein, at least one of the sub-virtual image planes is tilted toward the direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 45°.

[0048] Wherein, at least one of the sub-virtual image planes is tilted toward the direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 75°.

[0049] The distance between the vertex of the sub-virtual image plane and the center point of the corresponding sub-eye box plane is VID1, and the distance between the bottom point of the sub-virtual image plane and the center point of the corresponding sub-eye box plane is VID2, and VID1>VID2.

[0050] Among them, VID1 / VID2≥1.5.

[0051] Wherein, multiple theoretical wedge angle values ​​for measuring the wedge angle and eliminating the secondary image are present at any point within the segment, the measured wedge angles at each point within the segment are fitted to obtain an actual wedge angle fitting line, and multiple theoretical wedge angle values ​​at each point within the segment are fitted to obtain a first theoretical wedge angle fitting line, and a maximum deviation between the actual wedge angle fitting line and the first theoretical wedge angle fitting line is less than or equal to 0.07 mrad.

[0052] The actual wedge angle fitting line and the first theoretical wedge angle fitting line both conform to a polynomial function.

[0053] The maximum rate of change ROC of the wedge angle continuously and monotonically decreasing within the segment is: ROC≤0.3mrad / 100mm; or, ROC≤0.2mrad / 100mm; or, ROC≤0.1mrad / 100mm; or, ROC≤0.05mrad / 100mm.

[0054] Wherein, the angle between two adjacent sub-virtual image planes among the multiple sub-virtual image planes is less than or equal to 15°.

[0055] Wherein, in the direction from the bottom edge of the glass of the laminated glass to the top edge of the glass, the ratio of the length of the segment to the length of the projection display area is not less than 70%.

[0056] Wherein, the at least one projection display area includes:

[0057] At least one first projection display area, the projection light source is incident on the first projection display area to form a first projection image, and the virtual image distance of the first projection image is 7 meters to 100 meters;

[0058] and at least one second projection display area, the projection light source is incident on the second projection display area to form a second projection image, and the virtual image distance of the second projection image is 1 meter to 6 meters.

[0059] The at least one projection light source includes at least one first projection light source and at least one second projection light source, the first projection light source is incident on the first projection display area, and the second projection light source is incident on the second projection display area.

[0060] Wherein, the laminated glass comprises:

[0061] a first transparent substrate;

[0062] a second transparent substrate;

[0063] and an intermediate bonding layer, the intermediate bonding layer being provided between the first transparent substrate and the second transparent substrate and being used for bonding the first transparent substrate and the second transparent substrate;

[0064] At least one of the first transparent substrate, the second transparent substrate, and the intermediate adhesive layer has a wedge angle in the projection display area.

[0065] The wedge angles of the first transparent substrate and the second transparent substrate in the projection display area are both 0, and the intermediate adhesive layer has a wedge angle in the projection display area that is equal to the wedge angle of the projection display area.

[0066] Particularly, the first transparent substrate and / or the second transparent substrate has a wedge angle in the projection display area, the intermediate bonding layer has a wedge angle in the projection display area, and the sum of the wedge angles of the first transparent substrate and / or the second transparent substrate in the projection display area and the wedge angle of the intermediate bonding layer in the projection display area is equal to the wedge angle of the projection display area.

[0067] In a second aspect, the present application provides a design method for a head-up display system, the design method for a head-up display system comprising:

[0068] Providing a projection assembly and laminated glass, wherein projection light emitted by the projection assembly is incident on at least one projection display area on the laminated glass;

[0069] The eyebox surface located inside the vehicle is designed based on the observer inside the vehicle;

[0070] The virtual image plane is designed to be inclined toward the direction of observing the corresponding sub-virtual image plane from the sub-eye box surface according to the projection image observed by the observer in the car through each projection display area;

[0071] The eye box surface includes a plurality of sub-eye box surfaces, and the virtual image surface includes a plurality of sub-virtual image surfaces, wherein each sub-virtual image surface corresponds to a sub-eye box surface, and each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface. The upper virtual image surface and / or the lower virtual image surface of at least one of the sub-virtual image surfaces are inclined toward the direction in which the corresponding sub-virtual image surface is observed from the sub-eye box surface, and the forward tilt angle thereof is greater than or equal to 45°.

[0072] An observation lattice is selected on each sub-eye box surface, and a virtual image lattice is selected on each sub-virtual image surface, wherein a line connecting points in the observation lattice and points in the virtual image lattice passes through a corresponding projection display area, and an intersection of the line and the projection display area is an incident point;

[0073] Calculating multiple theoretical wedge angle values ​​of the laminated glass when the projection image at the corresponding incident point position has no secondary image based on the projection assembly, the laminated glass, and the multiple connecting lines;

[0074] According to the plurality of theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass of the laminated glass corresponding to each theoretical wedge angle value, fitting is performed to obtain a first theoretical wedge angle fitting line representing the wedge angle as a function of the distance from the incident point to the bottom edge of the glass;

[0075] And determining the wedge angle value of the laminated glass in the corresponding projection display area according to the first theoretical wedge angle fitting line.

[0076] The “design of a virtual image plane tilted toward a direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane according to the projected image observed by an observer in the vehicle through each projection display area” includes:

[0077] At least one of the sub-virtual image planes is designed to face the direction in which the corresponding sub-virtual image plane is observed from the sub-eye box surface, and its forward tilt angle is greater than or equal to 45°.

[0078] The “design of a virtual image plane tilted toward a direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane according to the projected image observed by an observer in the vehicle through each projection display area” includes:

[0079] When the upper virtual image plane and / or the lower virtual image plane of the sub-virtual image plane is tilted toward the direction of observing the corresponding sub-virtual image plane from the sub-eye box plane, VID1>VID2;

[0080] The distance between the vertex of the sub-virtual image plane and the center point of the corresponding sub-eye box plane is VID1, and the distance between the bottom point of the sub-virtual image plane and the center point of the corresponding sub-eye box plane is VID2.

[0081] Among them, VID1 / VID2≥1.5.

[0082] The “design of a virtual image plane tilted toward a direction in which the corresponding sub-virtual image plane is observed from the sub-eye box plane according to the projected image observed by an observer in the vehicle through each projection display area” includes:

[0083] It is designed that the included angle between two adjacent sub-virtual image planes among the multiple sub-virtual image planes is less than or equal to 15°.

[0084] The ratio of the maximum local extreme difference ΔW of the plurality of theoretical wedge angle values ​​to the overall extreme difference ΔC of the plurality of theoretical wedge angle values ​​is: ΔW / ΔC≤0.9.

[0085] The at least one projection display area includes at least two first projection display areas, or at least two second projection display areas, and at least two first theoretical wedge angle fitting lines are obtained by fitting, where the wedge angle varies with the distance from the incident point to the bottom edge of the glass. When the maximum deviation between two adjacent first theoretical wedge angle fitting lines is greater than 0.15 mrad, after "determining the wedge angle value of the laminated glass in the corresponding projection display area according to the first theoretical wedge angle fitting line," the design method of the head-up display system further includes:

[0086] adjusting the distance between the eye box surface and a virtual image surface corresponding to one of two adjacent first theoretical wedge angle fitting lines;

[0087] Recalculating and obtaining a plurality of new theoretical wedge angle values;

[0088] According to the multiple new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass corresponding to each theoretical wedge angle value, fitting is performed to obtain a second theoretical wedge angle fitting line corresponding to the wedge angle and the distance from the incident point to the bottom edge of the glass;

[0089] and determining whether a maximum deviation value between the second theoretical wedge angle fitting line and the other of the two adjacent first theoretical wedge angle fitting lines is less than or equal to 0.15 mrad;

[0090] If not, repeat the above steps;

[0091] If so, the wedge angle value of the laminated glass in the corresponding first projection display area or the second projection display area is determined according to the second theoretical wedge angle fitting line.

[0092] The at least one projection display area includes at least one first projection display area and at least one second projection display area, and at least two first theoretical wedge angle fitting lines are obtained by fitting, where the wedge angle varies with the distance from the incident point to the bottom edge of the glass. When the maximum deviation between two adjacent first theoretical wedge angle fitting lines is greater than 0.2 mrad, after "determining the wedge angle value of the laminated glass in the corresponding projection display area according to the first theoretical wedge angle fitting line," the head-up display system design method further includes:

[0093] adjusting the distance between the eye box surface and a virtual image surface corresponding to one of two adjacent first theoretical wedge angle fitting lines;

[0094] Recalculating and obtaining a plurality of new theoretical wedge angle values;

[0095] According to the multiple new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass corresponding to each theoretical wedge angle value, fitting is performed to obtain a third theoretical wedge angle fitting line representing the wedge angle as the distance from the incident point to the bottom edge of the glass increases;

[0096] and determining whether a maximum deviation value between the third theoretical wedge angle fitting line and the other of the two adjacent first theoretical wedge angle fitting lines is less than or equal to 0.15 mrad;

[0097] If not, repeat the above steps;

[0098] If so, the wedge angle value of the laminated glass in the corresponding first projection display area or the second projection display area is determined according to the third theoretical wedge angle fitting line.

[0099] The adjusted set of the plurality of theoretical wedge angle values ​​has a maximum local range value △WU, the adjusted set of the plurality of theoretical wedge angle values ​​has an overall range value △CU, and the ratio of △WU to △CU is: △WU / △CU≤0.9.

[0100] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0101] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0102] References herein to "embodiments" or "implementations" mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of the present application. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor do they constitute independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0103] In this application, because the laminated glass is a transparent medium, light emitted by the projection light source enters the laminated glass, reflects off the inner surface of the laminated glass, and then enters the eyebox surface, forming an image in front of the glass, forming a first virtual image, referred to as the primary image. It will also reflect off the outer surface of the laminated glass again, enter the eyebox surface, and form an image in front of the laminated glass, forming a second virtual image. When the laminated glass contains a highly reflective dielectric layer, such as a metal coating containing Ag or highly reflective modified PET, reflections will also occur, generating a third or even more virtual images; these second, third, or even more virtual images are collectively referred to as secondary images. To eliminate secondary images, the laminated glass 10 needs to have a corresponding wedge angle in the projection display area 11. This allows the secondary image to overlap with the primary image, allowing the observer to see the head-up display (HUD) image through the projection display area 11 without the secondary image. Because the HUD image reflects light entering the eyebox EB1 at different angles in different areas of the projection display area 11, and because the observer's different sitting postures in the cab also cause the HUD image to enter the eyebox EB1 at different angles, the laminated glass 10 needs to have different wedge angles in different areas of the projection display area 11.

[0104] An embodiment of the present application provides a head-up display system 1. Referring to Figures 1, 2, 3, and 4, in this embodiment, the head-up display system 1 includes a laminated glass 10, a projection assembly 20, and an eyebox EB1. The laminated glass 10 has at least one projection display area 11. Each projection display area 11 has a wedge-shaped cross-section, wherein, when the laminated glass 10 is installed in a vehicle, the upper side 111 is thicker than the lower side 112, and the laminated glass 10 has a wedge-shaped cross-section with a wedge angle that continuously decreases from the lower side 112 to the upper side 111. The projection assembly 20 includes at least one projection light source 21 capable of projecting onto the at least one projection display area 11. Projection light emitted by the projection light source 21 is incident on the projection display area 11 to form a projected image 114. The projected image 114 has a virtual image surface TB10. The eyebox EB1 has an eyebox surface EB10 through which the projected image 114 is observed. The eye box surface EB10 includes multiple sub-eye box surfaces EB11 from low to high, and the virtual image surface TB10 includes multiple sub-virtual image surfaces TB11 from high to low corresponding to the multiple sub-eye box surfaces EB11. Each sub-virtual image surface TB11 includes an upper virtual image surface TB112 and a lower virtual image surface TB113. The upper virtual image surface TB112 and / or the lower virtual image surface TB113 of at least one of the sub-virtual image surfaces TB11 are inclined toward the direction of observing the corresponding sub-virtual image surface TB11 from the sub-eye box surface EB11, and the forward inclination angle between them and the vertical plane is greater than or equal to 45°.

[0105] It should be noted that FIG2 illustrates the number of sub-eyebox planes EB11 and sub-virtual image planes TB11 as being three each, and does not limit the number of sub-eyebox planes EB11 and sub-virtual image planes TB11. FIG3 illustrates the number of sub-virtual image planes TB11 as being tilted toward the direction in which the corresponding sub-virtual image plane TB11 is viewed from the sub-eyebox plane EB11. A vertical plane is a plane perpendicular to the ground and perpendicular to the direction in which the corresponding sub-virtual image plane TB11 is viewed from the sub-eyebox plane EB11.

[0106] In this embodiment, each projection display area 11 has a segment 113 whose wedge angle decreases continuously from the lower side 112 to the upper side 111. It will be appreciated that, within each projection display area 11, the wedge angle of segment 113 may decrease linearly or nonlinearly. Except for segment 113, the wedge angles of other segments within the projection display area 11 may be zero, have a constant wedge angle, increase linearly or nonlinearly, decrease linearly or nonlinearly, or decrease continuously along with the wedge angle of segment 113.

[0107] In this embodiment, the head-up display system 1 is applied to a vehicle and realizes information display in front of the front windshield. The head-up display system 1 includes a projection component 20. The image projected by the projection component 20 onto the at least one projection display area 11 includes at least one of one or more types of HUD images, one or more angle HUD images, and one or more distance display HUD images, so that the head-up display system 1 has multi-information display, which increases the richness of the image display of the head-up display system 1. The at least one projection display area 11 is used to display HUD images. Specifically, the at least one projection display area 11 can be used to set an augmented reality head-up display (AR-HUD) or a windshield head-up display (W-HUD).

[0108] In this embodiment, the projection assembly 20 includes at least one projection light source 21 projected onto the at least one projection display area 11. One projection light source 21 is provided corresponding to one projection display area 11, or one projection light source 21 is provided corresponding to a plurality of projection display areas 11. In one embodiment, the projection light emitted by the projection light source 21 is directly incident on the projection display area 11. In another embodiment, the projection light emitted by the projection light source 21 is incident on the projection display area 11 through a reflection device. The projection light emitted by the projection light source 21 is incident on the projection display area 11 to form a projection image 114, and the projection image 114 is displayed in front of the laminated glass 10, and the projection image 114 has a virtual image surface TB10 located outside the vehicle when the laminated glass 10 is installed in the vehicle.

[0109] In this embodiment, the eye box EB1 simulates the driver's eye in the vehicle cab for viewing the projected image 114. The eye box EB1 has an eye box surface EB10 that allows viewing the projected image 114 through the projection display area 11. The eye box surface EB10 is the central cross-section of the eye box EB1 perpendicular to the ground and perpendicular to the direction from the sub-eye box surface EB11 to the corresponding sub-virtual image plane TB11.

[0110] Next, the head-up display system 1 is applied to the front windshield of a vehicle for exemplary description. The projection light emitted by the projection light source 21 in the projection assembly 20 is incident on the projection display area 11. The projection display area 11 reflects at least part of the projection light into the eye box surface EB10, forming a projection image 114 in front of the laminated glass 10 of the vehicle. The projection image 114 has the virtual image surface TB10. According to the height of the eye box EB1 in the cab of the vehicle, the eye box surface EB10 includes a plurality of sub-eye box surfaces EB11 from low to high. Correspondingly, the projection light forming the projection image 114 enters the sub-eye box surfaces EB11 at different positions and has sub-virtual image surfaces TB11 at different positions. The sub-virtual image surface TB11 includes a plurality of sub-virtual image surfaces TB11 from high to low corresponding to the plurality of sub-eye box surfaces EB11 from low to high. Because the laminated glass 10 has a certain thickness, when the projection light emitted by the projection light source 21 is incident on the projection display area 11, the projection light is reflected from the inner surface of the laminated glass 10 onto the eyebox surface EB10, forming a primary image of the projected image 114. Furthermore, the projection light is reflected from the outer surface of the laminated glass 10 and / or the highly reflective dielectric layer within the laminated glass 10 onto the eyebox surface EB10, forming one or more secondary images. Therefore, a wedge angle is required in the projection display area 11 to eliminate the secondary images, that is, to ensure that the secondary images overlap with the primary image. Furthermore, the theoretical wedge angle required to eliminate the secondary images at the same point in the projection display area 11 observed from different points on the eyebox surface EB10 varies. Therefore, multiple theoretical wedge angle values ​​are available for each point in the projection display area 11 to eliminate the secondary images. However, in actual production of laminated glass 10, each point in the projection display area 11 can only have one wedge angle value. Therefore, it is necessary to calculate the optimal wedge angle value by fitting the multiple theoretical wedge angle values ​​for each point in the projection display area 11.

[0111] In the prior art, the virtual image plane of a conventional head-up display system is approximately perpendicular to the ground, resulting in a large degree of discrete distribution of multiple theoretical wedge angle values ​​for eliminating the secondary image at each point in the projection display area 11. This results in a large deviation between the wedge angle value selected at each point in the projection display area 11 and the theoretical wedge angle value required for eliminating the secondary image, making it difficult and ineffective for the head-up display system 1 to eliminate the secondary image.

[0112] Compared to the prior art, in the head-up display system 1 provided by the present application, each sub-virtual image plane TB11 includes an upper virtual image plane TB112 and a lower virtual image plane TB113. For each sub-virtual image plane TB11, a line is drawn between the center point of the sub-virtual image plane TB11 and the center point of the corresponding sub-eye box plane EB11. A line is also drawn through the center point of the sub-virtual image plane TB11, parallel to the ground and perpendicular to the direction in which the corresponding sub-virtual image plane TB11 is viewed from the sub-eye box plane EB11. The plane formed by the line and the line is used as a reference plane. The portion of the sub-virtual image plane TB11 located above the reference plane is the upper virtual image plane TB112, and the portion of the sub-virtual image plane TB11 located below the reference plane is the lower virtual image plane TB113.

[0113] By tilting the upper virtual image plane TB112 in the sub-virtual image plane TB11 toward the direction in which the corresponding sub-virtual image plane TB11 is observed from the sub-eye box plane EB11, that is, achieving a local forward tilt of the projected image 114, the distance between the upper virtual image plane TB112 and the sub-eye box plane EB11 corresponding to the sub-virtual image plane TB11 is increased, thereby reducing the theoretical wedge angle value required to eliminate the secondary image corresponding to the upper virtual image plane TB112, and further reducing the local discrete distribution of multiple theoretical wedge angle values ​​in the projection display area 11, so that the distribution of the multiple theoretical wedge angle values ​​converges towards the actual wedge angle fitting line, that is, reducing the local extreme difference values ​​of the multiple theoretical wedge angle values.

[0114] By tilting the lower virtual image surface TB113 in the sub-virtual image surface TB11 toward the direction of the corresponding sub-virtual image surface observed from the sub-eye box surface, that is, achieving a local forward tilt of the projected image 114, the distance between the lower virtual image surface TB113 and the sub-eye box surface EB11 corresponding to the sub-virtual image surface TB11 is reduced, thereby increasing the theoretical wedge angle value required to eliminate the secondary image corresponding to the upper virtual image surface TB112, and further reducing the local discrete distribution of the multiple theoretical wedge angle values ​​in the projection display area 11, so that the distribution of the multiple theoretical wedge angle values ​​converges towards the actual wedge angle fitting line, that is, reducing the local extreme difference values ​​of the multiple theoretical wedge angle values.

[0115] The upper virtual image surface TB112 and the lower virtual image surface TB113 in the sub-virtual image surface TB11 are both tilted toward the direction of the corresponding sub-virtual image surface observed from the sub-eye box surface, that is, the projected image 114 is tilted forward as a whole, thereby reducing the overall discrete distribution of the multiple theoretical wedge angle values ​​in the projection display area 11, and making the distribution of the multiple theoretical wedge angle values ​​converge toward the actual wedge angle fitting line L0, that is, reducing the local extreme values ​​of the multiple theoretical wedge angle values.

[0116] Therefore, by tilting the upper virtual image plane TB112 and / or the lower virtual image plane TB113 in the sub-virtual image plane TB11 toward the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11, the effect of eliminating secondary images of the head-up display system 1 is ultimately improved.

[0117] The greater the forward tilt angles of the upper virtual image plane TB112 and the lower virtual image plane TB113, the smaller the discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the secondary image in the projection display area 11. Furthermore, the forward tilt angles can be adjusted by the projection assembly 20, for example, by adjusting the tilt angles of the curved reflector and the PGU surface in the projection assembly 20 to set the forward tilt angles of the upper virtual image plane TB112 and the lower virtual image plane TB113.

[0118] In addition, when the upper virtual image surface TB112 and / or the lower virtual image surface TB113 are tilted toward the direction of the corresponding sub-virtual image surface TB11 observed from the sub-eye box surface EB11 and the forward tilt angle is large, the upper virtual image surface TB112 and / or the lower virtual image surface TB113 are approximately flat on the ground, so that the driver feels a better sense of ground contact and enhanced reality when observing the projected image 114, thereby improving the driving experience.

[0119] Specifically, the forward tilt angle of the upper virtual image plane TB112 and / or the lower virtual image plane TB113 of at least one of the sub-virtual image planes TB11 is greater than or equal to 45°, or greater than or equal to 60°, or greater than or equal to 75°, or equal to 90° (to achieve ground alignment), which can significantly improve the secondary image phenomenon in the projection display area 11. In addition, in some special scenarios, the forward tilt angle of the upper virtual image plane TB112 and / or the lower virtual image plane TB113 of at least one of the sub-virtual image planes TB11 is greater than 90° and less than or equal to 95°.

[0120] It should be noted that each of the sub-virtual image surfaces TB11 may be a plane (see (a) in FIG4 ) or a curved surface (see (b) and (c) in FIG4 ). A line is connected between the center point of each sub-eye box surface EB11 and the center point of the corresponding sub-virtual image surface TB11, and a plane passing through the line and perpendicular to the ground is used as the main optical axis plane. The intersection line of the main optical axis plane and the corresponding sub-virtual image surface TB11 has a vertex and a base point, and the forward tilt angle α of the upper virtual image surface TB112 is U The angle between the line connecting the vertex and the center point of the corresponding sub-virtual image plane TB11 and the vertical plane is tilted in the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box surface EB11, and the forward tilt angle of the lower virtual image plane TB113 is α LThe angle α0 of the line connecting the bottom point and the center point of the corresponding sub-virtual image plane TB11 is tilted toward the direction of the corresponding sub-virtual image plane TB11 observed from the sub-eye box surface EB11 and is the angle between the line connecting the top point and the bottom point and the vertical plane.

[0121] In addition, among the multiple sub-virtual image planes TB11, the greater the number of upper virtual image planes TB112 and lower virtual image planes TB113 with a forward tilt angle greater than or equal to 45°, the better the head-up display system 1 can eliminate secondary images in the multiple sub-eye box planes EB11, that is, the clearer the driver can observe the projected image 114 at various heights in the cab, thereby improving the driving experience.

[0122] In summary, the present application provides a head-up display system 1, which includes a laminated glass 10, a projection assembly 20, and an eye box EB1. The projection light source 21 in the projection assembly 20 projects the projection image 114 formed on at least one projection display area 11 on the laminated glass 10, and the projection image 114 has a virtual image surface TB10. The eye box EB1 has an eye box surface EB10 through which the projection image 114 is observed. The virtual image surface TB10 has a plurality of sub-virtual image surfaces TB11 corresponding to a plurality of sub-eye box surfaces EB11 at different positions in the eye box surface EB10. Each sub-virtual image surface TB11 includes an upper virtual image surface TB112 and a lower virtual image surface TB113. At least one of the sub-virtual image surfaces TB11 is a virtual image surface TB112. The upper virtual image surface TB112 and / or the lower virtual image surface TB113 of the sub-virtual image surface TB11 are tilted toward the direction in which the corresponding sub-virtual image surface TB11 is viewed from the sub-eyebox surface EB11, and their forward tilt angle is greater than or equal to 45°. This reduces the local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate secondary images in the projection display area 11, thereby converging the distribution of the multiple theoretical wedge angle values ​​toward the actual wedge angle fitting line. This reduces the local extreme differences in the multiple theoretical wedge angle values, thereby improving the effectiveness of the head-up display system 1 in eliminating secondary images. Furthermore, the upper virtual image surface TB112 and / or the lower virtual image surface TB113 of at least one of the sub-virtual image surfaces TB11 are approximately flat on the ground, allowing the driver to experience a greater sense of ground contact and augmented reality when observing the projected image 114, thereby enhancing the driving experience. Therefore, the head-up display system 1 provided by the present application can reduce or even eliminate the problem of projected secondary images, thereby improving the driving experience.

[0123] Referring to Figures 5 and 6 , in this embodiment, at least one of the sub-virtual image planes TB11 is tilted toward the direction in which the corresponding sub-virtual image plane TB11 is viewed from the sub-eyebox plane EB11, and its forward tilt angle is greater than or equal to 45°. Figure 5 illustrates the sub-virtual image plane TB11 as being concave toward the ground. It is understood that Figure 5 does not limit the shape of the sub-virtual image plane TB11.

[0124] On the principal optical axis plane (see FIG. 5 ), the forward tilt angle α0 of at least one of the multiple sub-virtual image planes TB11 is greater than or equal to 45°, or greater than or equal to 60°, or greater than or equal to 75°, or equal to 90° (to achieve ground alignment), thereby achieving an overall forward tilt of the projected image 114 and significantly improving the secondary image phenomenon in the projection display area 11. Furthermore, in some special scenarios, the forward tilt angle α0 of at least one of the sub-virtual image planes is greater than 90° and less than or equal to 95°.

[0125] Specifically, FIG6 illustrates the two highest and lowest sub-eye box surfaces EB11 and the corresponding two sub-virtual image planes TB11 among the multiple sub-eye box surfaces EB11. The dashed box in FIG6 represents the scatterplot distribution profile of multiple theoretical wedge angle values ​​when the two sub-virtual image planes TB11 are not tilted forward, and when the corresponding two sub-virtual image planes TB11 are observed from the two highest and lowest sub-eye box surfaces EB11, the scattered distribution profile of multiple theoretical wedge angle values ​​when the corresponding two sub-virtual image planes TB11 are not tilted forward. The solid box in FIG6 represents the scatterplot distribution profile of multiple theoretical wedge angle values ​​when the corresponding two sub-virtual image planes TB11 are observed from the two highest and lowest sub-eye box surfaces EB11, when the tilt angle of the two sub-virtual image planes TB11 is greater than or equal to 45°. The dashed line segment within the dashed box represents the line connecting the multiple theoretical wedge angle values ​​when the center point of the sub-virtual image plane TB11 is observed from the perpendicular bisector of the sub-eye box surface EB11, and the non-projected secondary image. ΔW represents the maximum value among the local extreme values, wherein the local extreme value is the difference between the maximum value and the minimum value among the multiple theoretical wedge angle values ​​at a certain position at a distance X from the bottom edge 12 of the glass. ΔW before It represents the maximum value among the local extreme differences of multiple theoretical wedge angle values ​​when the two sub-virtual image surfaces TB11 are not tilted forward, △W after The maximum local extreme difference value among multiple theoretical wedge angle values ​​when the forward tilt angle of the two sub-virtual image surfaces TB11 is greater than or equal to 45° is shown in FIG6 . As can be seen from FIG6 , when the forward tilt angle of the two sub-virtual image surfaces TB11 is greater than or equal to 45°, the maximum local extreme difference value among multiple theoretical wedge angle values ​​for eliminating the projected secondary image is reduced by ΔW1+ΔW2 compared to when the two sub-virtual image surfaces TB11 do not tilt forward. Furthermore, the distribution of the multiple theoretical wedge angle values ​​for eliminating the projected secondary image converges toward the dashed segment within the dashed frame, thereby enhancing the improvement effect of the projected secondary image.

[0126] Please refer to Figure 3 again. In this embodiment, the intersection line of the main optical axis plane and the corresponding sub-virtual image plane TB11 has a vertex and a base point. The distance between the vertex of the sub-virtual image plane TB11 and the center point of the corresponding sub-eye box plane EB11 is VID1, and the distance between the base point of the sub-virtual image plane TB11 and the center point of the corresponding sub-eye box plane EB11 is VID2. When the sub-virtual image plane TB11 is tilted toward the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11, VID1>VID2, thereby improving the projected secondary image.

[0127] 3 and 7 again, in this embodiment, the sub-virtual image plane TB11 is tilted toward the direction in which the corresponding sub-virtual image plane TB11 is observed from the sub-eye box plane EB11, and VID1 / VID2≥1.5.

[0128] On the principal optical axis plane (see FIG3 ), the angle between the line connecting the center point of the sub-eyebox surface EB11 and the center point of the corresponding sub-virtual image surface TB11 and the ground is the lower viewing angle LDA. When the center point of the sub-virtual image surface TB11 is below the center point of the sub-eyebox surface EB11, the lower viewing angle LDA is negative, and vice versa. The angle between the line connecting the center point of the sub-eyebox surface EB11 and the vertex of the corresponding sub-virtual image surface TB11, and the line connecting the center point of the sub-eyebox surface EB11 and the base of the corresponding sub-virtual image surface TB11 is the vertical field of view angle VFOV.

[0129] Taking the lower viewing angle LDA = -1.5 / -2.5 / -3.5 / -4.5 degrees and the vertical field of view VFOV = 2.5 / 3.0 / 3.5 / 4.0 / 4.5 / 5.0 / 5.5 / 6.0 degrees as an example (see Figure 7), the relationship between VID1 / VID2 and the forward tilt angle of the sub-virtual image plane TB11 is simulated and calculated. The horizontal axis represents the forward tilt angle of the sub-virtual image plane TB11, and the vertical axis represents VID1 / VID2. Each line represents the case where the lower viewing angle LDA corresponds to the vertical field of view VFOV. The simulation results show that the larger the vertical field of view VFOV, the larger the ratio of VID1 to VID2, thereby eliminating the scattered distribution of multiple theoretical wedge angle values ​​for the projected secondary image, and the more obvious the improvement effect of the corresponding secondary image.

[0130] In addition, when the lower viewing angle LDA is constant, the greater the forward tilt angle of the sub-virtual image plane TB11 is, the greater the ratio of VID1 / VID2 is, and the more obvious the improvement effect of the corresponding secondary image is.

[0131] In addition, when VID1 / VID2≥1.5, the corresponding forward tilt angle of the sub-virtual image plane TB11 is greater than or equal to 75°, the improvement effect of the corresponding secondary image is more obvious, and it can also bring a better sense of ground contact and reality enhancement.

[0132] 8 , in this embodiment, multiple theoretical wedge angle values ​​for measuring the wedge angle and eliminating secondary images are present at any point within the segment 113. The measured wedge angles at each point within the segment 113 are fitted to obtain an actual wedge angle fitting line L0. Multiple theoretical wedge angle values ​​at each point within the segment 113 are fitted to obtain a first theoretical wedge angle fitting line L1. A maximum deviation between the actual wedge angle fitting line L0 and the first theoretical wedge angle fitting line L1 is less than or equal to 0.07 mrad.

[0133] In this embodiment, the first theoretical wedge angle fitting line L1 is a line obtained by fitting multiple theoretical wedge angle values ​​when the projected image 114 is observed through the eyebox surface EB10 within the segment 113 of the projection display area 11 without projecting a secondary image. The maximum deviation Δαmax between the actual wedge angle fitting line L0 and the first theoretical wedge angle fitting line L1 is less than or equal to 0.07 mrad. This ensures that the wedge angle values ​​at each point on the actual wedge angle fitting line L0 deviate slightly from the theoretical wedge angle values ​​required to eliminate secondary images, thereby ensuring that the wedge angle of the projection display area 11 can improve the problem of projecting a secondary image when observing the projected image 114 through the eyebox surface EB10.

[0134] Referring to FIG. 8 again, in this embodiment, the actual wedge angle fitting line L0 and the first theoretical wedge angle fitting line L1 both conform to polynomial functions.

[0135] In this embodiment, the actual wedge angle fitting line L0 and the first theoretical wedge angle fitting line L1 can be a straight line, a curve, or a combination of a straight line and a curve, as long as the actual wedge angle fitting line L0 and the first theoretical wedge angle fitting line L1 conform to a polynomial function. The actual wedge angle fitting curve is smoothed to prevent sudden changes in local wedge angle values ​​from exacerbating the projected secondary image problem.

[0136] Referring again to FIG. 8 , in this embodiment, the maximum rate of change ROC of the continuously monotonically decreasing wedge angle in the section 113 is: ROC≤0.3 mrad / 100 mm; or, ROC≤0.2 mrad / 100 mm; or, ROC≤0.1 mrad / 100 mm; or, ROC≤0.05 mrad / 100 mm.

[0137] In this embodiment, L0 in FIG8 represents the variation of the wedge angle of each segment 113 in the projection display area 11 as the distance from the bottom edge 12 of the laminated glass 10 changes. K1 is the tangent line to L0 at a specific point, and the slope of the tangent line represents the absolute value of the rate of change of the wedge angle at that point. A large maximum rate of change of the wedge angle within the segment 113 increases the difficulty and cost of manufacturing the laminated glass 10, which is detrimental to the production efficiency of the laminated glass 10 and thus affects the production efficiency of the laminated glass 10. Furthermore, a large maximum rate of change of the wedge angle within the segment 113 can easily lead to abrupt changes in the local wedge angle, exacerbating the projection secondary image problem. Therefore, the maximum rate of change of the wedge angle within the segment 113 should not be too large. Specifically, the maximum rate of change (ROC) of the wedge angle within the segment 113, where it continuously and nonlinearly decreases monotonically from the lower edge 112 to the upper edge 111, is: ROC ≤ 0.3 mrad / 100 mm. Preferably, the maximum rate of change (ROC) of the wedge angle in the section 113 that continuously and nonlinearly monotonically decreases from the lower side 112 to the upper side 111 is: ROC ≤ 0.2 mrad / 100 mm. More preferably, the maximum rate of change (ROC) of the wedge angle in the section 113 that continuously and nonlinearly monotonically decreases from the lower side 112 to the upper side 111 is: ROC ≤ 0.1 mrad / 100 mm. More preferably, the maximum rate of change (ROC) of the wedge angle in the section 113 that continuously and nonlinearly monotonically decreases from the lower side 112 to the upper side 111 is: ROC ≤ 0.05 mrad / 100 mm.

[0138] Referring to FIG. 2 again, in this embodiment, the angle between two adjacent sub-virtual image planes TB11 among the plurality of sub-virtual image planes TB11 is less than or equal to 15°.

[0139] In this embodiment, the angle between two adjacent sub-virtual image surfaces TB11 among the multiple sub-virtual image surfaces TB11 is less than or equal to 15°, preferably less than or equal to 10°, more preferably less than or equal to 5°, and more preferably less than or equal to 2°. Since, among the multiple sub-virtual image surfaces TB11, the sub-virtual image surface TB11 located in the middle of the multiple sub-virtual image surfaces TB11 serves as an interface. Since the local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the projection secondary image in the projection display area 11 corresponding to the multiple sub-virtual image surfaces TB11 increases from the interface upward, the local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the projection secondary image in the projection display area 11 corresponding to the multiple sub-virtual image surfaces TB11 also increases from the interface downward. Therefore, the forward tilt angle of the sub-virtual image plane TB11 gradually increases from the interface upward, and the forward tilt angle of the sub-virtual image plane TB11 gradually increases from the interface downward. This results in a smaller local discrete distribution of the theoretical wedge angle values ​​required to eliminate the projected secondary image in the projection display area 11 corresponding to the multiple sub-virtual image planes TB11, and a convergence of the distribution of the multiple theoretical wedge angle values ​​toward the actual wedge angle fitting line L0. That is, the local extreme values ​​of the multiple theoretical wedge angle values ​​are smaller, which can better improve the projected secondary image problem of the projected image 114 observed on the multiple sub-eye box planes EB11. To ensure that the driver has a consistent imaging experience when observing the projected image 114 at different heights in the cab, the angle between two adjacent sub-virtual image planes TB11 among the multiple sub-virtual image planes TB11 is less than or equal to 15°, preferably less than or equal to 10°, more preferably less than or equal to 5°, and more preferably less than or equal to 2°, thereby improving the driving experience.

[0140] Among them, the angle between two adjacent sub-virtual image surfaces TB11 refers to the angle between the extension line of the line connecting the vertex and the bottom point of one of the two adjacent sub-virtual image surfaces TB11 and the extension line of the line connecting the vertex and the bottom point of the other sub-virtual image surface TB11 on the main optical axis plane.

[0141] Referring again to FIG. 1 , in this embodiment, in the direction from the bottom edge 12 of the laminated glass 10 to the top edge 13 of the glass, the ratio of the length of the segment 113 to the length of the projection display area 11 is not less than 70%.

[0142] In this embodiment, in the direction from the bottom edge 12 of the laminated glass 10 to the top edge 13 of the glass, the ratio of the length d1 of the segment 113 to the length d2 of the projection display area 11 is not less than 70%. Preferably, the ratio of the length of the segment 113 to the length of the projection display area 11 is not less than 75%, or not less than 80%, or not less than 85%, or not less than 90%, or not less than 95%, or equal to 100%. The length is measured in the direction from the lower side 112 to the upper side 111.

[0143] 9 and 10 , in this embodiment, the at least one projection display area 11 includes at least one first projection display area 115 and at least one second projection display area 116. The projection light source 21 is incident on the first projection display area 115 to form a first projection image 1151. The virtual image distance of the first projection image 1151 is 7 meters to 100 meters. The projection light source 21 is incident on the second projection display area 116 to form a second projection image 1161. The virtual image distance of the second projection image 1161 is 1 meter to 6 meters.

[0144] In this embodiment, the first projection display area 115 is used for long-distance projection display. Specifically, the first projection display area 115 is used to integrate display information with the real scene, and is used to project and display complex graphics corresponding to objects in the real world, thereby realizing interaction between road conditions, vehicles, and drivers. The second projection display area 116 is used for short-distance projection display. Specifically, the second projection display area 116 is used for short-distance projection display. Specifically, the second projection display area 116 is used to display vehicle operating parameter information at close range, which can reduce the need to look down at the instrument panel or related information, facilitate the driver's eye switching between long and short distances, reduce the need to look down at the instrument panel, maximize the driver's attention while driving, and improve driving safety.

[0145] Please refer to Figure 11. In this embodiment, the at least one projection light source 21 includes at least one first projection light source 211 and at least one second projection light source 212. The first projection light source 211 is incident on the first projection display area 115, and the second projection light source 212 is incident on the second projection display area 116.

[0146] In this embodiment, the first projection light source 211 is used to project onto the first projection display area 115 for long-distance projection display. Specifically, the first projection display area 115 is used to integrate display information with the real scene and project complex graphics corresponding to real-world objects, enabling interaction between road conditions, vehicle conditions, and the driver. The second projection light source 212 is used to project onto the second projection display area 116 for close-range projection display. Specifically, the second projection display area 116 is used to display vehicle operating parameter information at close range, which can reduce the need to look down at the instrument panel or related information, facilitate the driver's eye switching between long and short distances, reduce the need to look down at the instrument panel, maximize the driver's attention while driving, and improve driving safety. In one embodiment, both the first projection light source 211 and the second projection light source 212 are positioned near the bottom edge 12 of the glass. In another embodiment, the first projection light source 211 is positioned near the top edge 13 of the glass, so that the projection light from the first projection light source 211 incident on the first projection display area 115 can maintain an optimal angle of incidence. Specifically, the first projection light source 211 is mounted on the inner surface of the vehicle roof. The second projection light source 212 is positioned near the bottom edge 12 of the glass, so that the projection light from the second projection light source 212 incident on the second projection display area 116 can maintain an optimal angle of incidence. Specifically, the second projection light source 212 is installed inside the vehicle's instrument panel. It should be noted that Figure 11 illustrates the first projection light source 211 and the second projection light source 212 being positioned near the bottom edge 12 of the glass. It is understood that Figure 11 does not limit the positions of the first projection light source 211 and the second projection light source 212.

[0147] Referring to Figure 12 , in this embodiment, the laminated glass 10 includes a first transparent substrate 14, a second transparent substrate 15, and an intermediate bonding layer 16. The intermediate bonding layer 16 is disposed between the first transparent substrate 14 and the second transparent substrate 15 to bond the first transparent substrate 14 and the second transparent substrate 15. At least one of the first transparent substrate 14, the second transparent substrate 15, and the intermediate bonding layer 16 has a wedge angle in the projection display area 11.

[0148] In one embodiment, the wedge angle in the projection display area 11 can be provided only by the intermediate bonding layer 16, that is, the wedge angles of the first transparent substrate 14 and the second transparent substrate 15 in the projection display area 11 are both 0, and the intermediate bonding layer 16 has a wedge angle in the projection display area 11, which is equal to the wedge angle of the projection display area 11.

[0149] In another embodiment, the wedge angle in the projection display area 11 can be provided by the first transparent substrate 14 and / or the second transparent substrate 15 and the intermediate bonding layer 16. That is, the first transparent substrate 14 and / or the second transparent substrate 15 have a wedge angle in the projection display area 11, the intermediate bonding layer 16 has a wedge angle in the projection display area 11, and the sum of the wedge angles of the first transparent substrate 14 and / or the second transparent substrate 15 in the projection display area 11 and the wedge angle of the intermediate bonding layer 16 in the projection display area 11 is equal to the wedge angle of the projection display area 11. Considering the difficulty in producing the first transparent substrate 14 and / or the second transparent substrate 15, the wedge angles of the first transparent substrate 14 and / or the second transparent substrate 15 are selected to be constant.

[0150] The present application also provides a design method for a head-up display system 1. Referring to Figures 4, 13, 14, and 15, in this embodiment, the design method for the head-up display system 1 includes providing a projection assembly 20 and laminated glass 10. Projection light emitted by the projection assembly 20 is incident on at least one projection display area 11 on the laminated glass 10. An eyebox surface EB10 located within the vehicle is designed based on the viewer within the vehicle. A virtual image surface TB10 is designed to be tilted toward the direction in which the corresponding sub-virtual image surface TB11 is viewed from the sub-eyebox surface EB11, based on the projected image 114 observed by the observer within the vehicle through each projection display area 11. The eye box surface EB10 includes a plurality of sub-eye box surfaces EB11 arranged in descending order, and the virtual image surface TB10 includes a plurality of sub-virtual image surfaces TB11 arranged in descending order, wherein each sub-virtual image surface TB11 corresponds to a sub-eye box surface EB11, and each sub-virtual image surface TB11 includes an upper virtual image surface TB112 and a lower virtual image surface TB113. The upper virtual image surface TB112 and / or the lower virtual image surface TB113 of at least one sub-virtual image surface TB11 are tilted toward the direction in which the corresponding sub-virtual image surface TB11 is observed from the sub-eye box surface EB11, and the forward tilt angle thereof is greater than or equal to 45°. An observation lattice EB111 is selected on each sub-eye box surface EB11, and a virtual image lattice TB111 is selected on each sub-virtual image surface TB11. The line connecting the points in the observation lattice EB111 and the points in the virtual image lattice TB111 passes through the corresponding projection display area 11, and the intersection of the line and the projection display area 11 is the incident point. Based on the projection assembly 20, the laminated glass 10, and the multiple connecting lines, multiple theoretical wedge angle values ​​of the laminated glass 10 when the projected image 114 at the corresponding incident point is free of a secondary image are calculated. Based on the multiple theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the laminated glass 10 corresponding to each theoretical wedge angle value, a fitting is performed to obtain a first theoretical wedge angle fitting line L1 that shows the wedge angle as a function of the distance from the incident point to the bottom edge 12 of the glass. Based on the first theoretical wedge angle fitting line L1, the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 is determined.

[0151] In this embodiment, the laminated glass 10 is used for a vehicle's front windshield and is employed in a vehicle's head-up display system 1. The design method for the laminated glass 10 includes steps S10, S20, S30, S40, S50, S60, and S70. Steps S10, S20, S30, S40, S50, S60, and S70 are described in detail below.

[0152] S10 , providing a projection assembly 20 and a laminated glass 10 , wherein the projection light emitted by the projection assembly 20 is incident on at least one projection display area 11 on the laminated glass 10 .

[0153] S20, designing an eye box surface EB10 located inside the vehicle according to an observer inside the vehicle.

[0154] S30 , designing a virtual image plane TB10 tilted toward a direction in which the corresponding sub-virtual image plane TB11 is observed from the sub-eye box plane EB11 according to the projection image 114 observed by the observer in the vehicle through each projection display area 11 .

[0155] In this embodiment, the eye box surface EB10 includes a plurality of sub-eye box surfaces EB11 arranged in order from low to high, and the virtual image surface TB10 includes a plurality of sub-virtual image surfaces TB11 arranged in order from high to low. Each sub-virtual image surface TB11 corresponds to a sub-eye box surface EB11. Specifically, the eye box surface EB10 is used to simulate the plane in which the eyes of an observer are located when sitting in the cab of a vehicle. The plurality of sub-eye box surfaces EB11 are used to simulate the observer's eyes being at different heights, that is, the plurality of sub-eye box surfaces EB11 are used to simulate the observer's different viewing angles. The projection display area 11 reflects at least a portion of the projection light into the eye box surface EB10, forming a projection image 114 in front of the laminated glass 10 of the vehicle, and the projection image 114 has the virtual image surface TB10. The projection light forming the projection image 114 enters the sub-eye box surfaces EB11 at different positions, resulting in sub-virtual image surfaces TB11 at different positions.

[0156] Among them, each sub-virtual image plane TB11 includes an upper virtual image plane TB112 and a lower virtual image plane TB113. For each sub-virtual image plane TB11, a line is drawn between the center point of the sub-virtual image plane TB11 and the center point of the corresponding sub-eye box plane EB11, and a straight line is drawn through the center point of the sub-virtual image plane TB11, which is parallel to the ground and perpendicular to the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11. The plane formed by the connecting line and the straight line is used as the reference plane. The part of the sub-virtual image plane TB11 located above the reference plane is the upper virtual image plane TB112, and the part of the sub-virtual image plane TB11 located below the reference plane is the lower virtual image plane TB113.

[0157] By tilting the upper virtual image plane TB112 in the sub-virtual image plane TB11 toward the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11, that is, realizing a local forward tilt of the projected image 114, the distance between the upper virtual image plane TB112 and the sub-eye box plane EB11 corresponding to the sub-virtual image plane TB11 is increased, thereby reducing the theoretical wedge angle value required to eliminate the secondary image corresponding to the upper virtual image plane TB112, and further reducing the local discrete distribution of multiple theoretical wedge angle values ​​in the projection display area 11, so that the distribution of the multiple theoretical wedge angle values ​​converges to the first theoretical wedge angle fitting line L1, that is, reducing the local extreme difference values ​​of the multiple theoretical wedge angle values.

[0158] By tilting the lower virtual image surface TB113 in the sub-virtual image surface TB11 toward the direction of the corresponding sub-virtual image surface observed from the sub-eye box surface, that is, achieving a local forward tilt of the projected image 114, the distance between the lower virtual image surface TB113 and the sub-eye box surface EB11 corresponding to the sub-virtual image surface TB11 is reduced, thereby increasing the theoretical wedge angle value required to eliminate the secondary image corresponding to the upper virtual image surface TB112, and further reducing the local discrete distribution of the multiple theoretical wedge angle values ​​in the projection display area 11, so that the distribution of the multiple theoretical wedge angle values ​​converges to the first theoretical wedge angle fitting line L1, that is, reducing the local extreme difference values ​​of the multiple theoretical wedge angle values.

[0159] The upper virtual image surface TB112 and the lower virtual image surface TB113 in the sub-virtual image surface TB11 are both tilted toward the direction of observing the corresponding sub-virtual image surface from the sub-eye box surface, that is, the projected image 114 is tilted forward as a whole, thereby reducing the overall discrete distribution of the multiple theoretical wedge angle values ​​in the projection display area 11, and making the distribution of the multiple theoretical wedge angle values ​​converge toward the first theoretical wedge angle fitting line L1, that is, reducing the local extreme values ​​of the multiple theoretical wedge angle values.

[0160] Therefore, by tilting the upper virtual image plane TB112 and / or the lower virtual image plane TB113 in the sub-virtual image plane TB11 toward the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11, the effect of eliminating secondary images of the head-up display system 1 is ultimately improved.

[0161] The greater the forward tilt angles of the upper virtual image plane TB112 and the lower virtual image plane TB113, the smaller the discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the secondary image in the projection display area 11. Furthermore, the forward tilt angles can be adjusted by the projection assembly 20, for example, by adjusting the tilt angles of the curved reflector and the PGU surface in the projection assembly 20 to set the forward tilt angles of the upper virtual image plane TB112 and the lower virtual image plane TB113.

[0162] In addition, when the upper virtual image surface TB112 and / or the lower virtual image surface TB113 are tilted toward the direction of the corresponding sub-virtual image surface TB11 observed from the sub-eye box surface EB11 and the forward tilt angle is large, the upper virtual image surface TB112 and / or the lower virtual image surface TB113 are approximately flat on the ground, so that the driver feels a better sense of ground contact and enhanced reality when observing the projected image 114, thereby improving the driving experience.

[0163] Specifically, the upper virtual image surface TB112 and / or the lower virtual image surface TB113 of at least one of the sub-virtual image surfaces TB11 are inclined toward the direction of observing the corresponding sub-virtual image surface TB11 from the sub-eye box surface EB11, and the forward inclination angle thereof is greater than or equal to 45°, or greater than or equal to 60°, or greater than or equal to 75°, or greater than or equal to 90° and less than or equal to 95°, which can significantly improve the secondary image phenomenon in the projection display area 11.

[0164] It should be noted that each of the sub-virtual image surfaces TB11 is designed to be a plane (see (a) in FIG4 ) or a curved surface (see (b) and (c) in FIG4 ). A line is connected between the center point of each sub-eye box surface EB11 and the center point of the corresponding sub-virtual image surface TB11, and a plane passing through the line and perpendicular to the ground is used as the main optical axis plane. The intersection line of the main optical axis plane and the corresponding sub-virtual image surface TB11 has a vertex and a base point, and the forward tilt angle α of the upper virtual image surface TB112 is U The angle between the line connecting the vertex and the center point of the corresponding sub-virtual image plane TB11 and the vertical plane is tilted in the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box surface EB11, and the forward tilt angle of the lower virtual image plane TB113 is α L The angle α0 is the angle between the line connecting the base point and the center point of the corresponding sub-virtual image plane TB11, which is tilted in the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box surface EB11, and the vertical plane. The forward tilt angle α0 of the sub-virtual image plane TB11 is the angle between the line connecting the vertex and the base point, which is tilted in the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box surface EB11, and the vertical plane. The vertical plane is a plane perpendicular to the ground and perpendicular to the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box surface EB11.

[0165] S40, select an observation dot matrix EB111 on each sub-eye box surface EB11, and select a virtual image dot matrix TB111 on each sub-virtual image surface TB11, the line connecting the points in the observation dot matrix EB111 and the points in the virtual image dot matrix TB111 passes through the corresponding projection display area 11, and the intersection of the line and the projection display area 11 is the incident point.

[0166] In this embodiment, an observation point matrix EB111 is selected on each sub-eye box surface EB11: m×n. Here, m ≥ 1 and is a natural number, and n ≥ 1 and is a natural number. For example, m can be, but is not limited to, 3, 5, or 8, and n can be, but is not limited to, 3, 5, or 8. A virtual image point matrix TB111 is selected on each sub-virtual image surface TB11: i×j. Here, i ≥ 1 and is a natural number, and j ≥ 1 and is a natural number. For example, i can be, but is not limited to, 3, 5, or 8, and j can be, but is not limited to, 3, 5, or 8.

[0167] In this embodiment, each point in the observation dot matrix EB111 corresponds to the position of a simulated observer's eye. Each point in the virtual image dot matrix TB111 simulates the virtual image formed on the virtual image plane by the projection light reflected from the laminated glass 10 at a certain point on the eyebox surface EB10. Specifically, each point in the virtual image dot matrix TB111 corresponds to one or more points in the observation dot matrix EB111, that is, an observer at a different position on the sub-eyebox surface EB11 can see a virtual image at the same position on the sub-virtual image plane TB11. In addition, an observer at the same position on the sub-eyebox surface EB11 can see virtual images at different positions on the sub-virtual image plane.

[0168] S50 , calculating, based on the projection assembly 20 , the laminated glass 10 and the plurality of connecting lines, a plurality of theoretical wedge angle values ​​of the laminated glass 10 when the projection image 114 at the corresponding incident point position has no secondary image.

[0169] In this embodiment, in each corresponding sub-eye box surface EB11 and sub-virtual image surface TB11, each point in the observation point matrix EB111 and each point in the virtual image point matrix TB111 intersect the laminated glass 10 at an intersection, i.e., an incident point. The theoretical wedge angle value at each incident point in the observation point matrix EB111, when an observer sees a virtual image on the sub-virtual image surface without a reflected secondary image, is calculated. The number of incident points used in the simulation calculation is the number of theoretical wedge angle values.

[0170] S60 , fitting is performed based on the multiple theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the glass of the laminated glass 10 corresponding to each theoretical wedge angle value to obtain a first theoretical wedge angle fitting line L1 that represents the wedge angle along the distance from the incident point to the bottom edge 12 of the glass.

[0171] In this embodiment, the multiple theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the laminated glass 10 exhibit a discrete distribution. Specifically, in one embodiment, a sub-discrete graph of the multiple theoretical wedge angle values ​​can be calculated for each corresponding sub-eyebox surface EB11 and sub-virtual image surface TB11. The multiple sub-discrete graphs are aggregated in the same coordinate system to form a discrete graph. A first theoretical wedge angle fitting line L1 is obtained by performing function fitting on the discrete graphs of the multiple theoretical wedge angle values. For example, the function can be, but is not limited to, a linear, quadratic, or cubic polynomial function, or a basic function such as a linear function, an exponential function, a power function, a logarithmic function, or a composite function thereof. The data curve fitting process can be performed in software such as Microsoft Excel, WPS, MATLAB, or OriginPro. Because an observer can see multiple images at different distances or angles at a given point on the laminated glass 10, the theoretical wedge angle value at that point can be multiple. However, the wedge angle value at a given point on the laminated glass 10 can only be a single value. Furthermore, other points at the same distance from this point along the direction from the bottom edge 12 to the top edge 13 of the glass also have multiple theoretical wedge angle values. The wedge angle value at a certain distance from the bottom edge 12 of the glass on the laminated glass 10 is suitable for a single value. Therefore, it is necessary to appropriately select the wedge angle value at each incident point on the laminated glass 10 to reduce the secondary image phenomenon. By performing function fitting on these multiple theoretical wedge angle values, the deviation between the wedge angle value of the laminated glass 10 on the projection display area 11 and these multiple theoretical wedge angle values ​​can be minimized, thereby reducing the secondary image phenomenon projected onto the projection display area 11 of the laminated glass 10 and improving the imaging quality of the laminated glass 10.

[0172] Specifically, set the wedge angle (Y HUD ) changes with the distance (X) from the bottom edge 12 to the top edge of the glass. The mathematical expression of the first theoretical wedge angle fitting line L1 can be in various forms, for example, HUD =A n ×X^ n +A (n-1) ×X^ (n-1)+…+A1×X+B (B is the wedge angle value when X=0). Generally, n=1~4 can be set, that is, a 1st to 4th order function. In addition, different weights can be set for the distribution ratio of people of different heights and sitting postures or certain specific points to reflect the corresponding theoretical wedge angle scatter points. For example, taking the number of the multiple sub-eye box surfaces EB11 as 3 as an example, the fitting weights of the theoretical wedge angle values ​​corresponding to the multiple sub-eye box surfaces EB11 corresponding to the height distribution from high to low are set to 1:1:1 (the weights of the sub-eye box surfaces EB11 of each height are the same), 3:2:2 (the weight of the sub-eye box surface EB11 with the highest height is heavier), 2:2:3 (the weight of the sub-eye box surface EB11 with the lowest height is heavier) or 2:3:2 (the weight of the sub-eye box surface EB11 in the middle is heavier), etc.

[0173] In another embodiment, for the multiple theoretical wedge angle values ​​corresponding to each of the incident points, the average of the maximum and minimum values ​​of the multiple theoretical wedge angle values ​​corresponding to the point is selected, and then the average of the maximum and minimum values ​​of the multiple theoretical wedge angle values ​​at each of the incident points are connected to form the first theoretical wedge angle fitting line L1.

[0174] S70 , determining a wedge angle value of the laminated glass 10 in the corresponding projection display area 11 according to the first theoretical wedge angle fitting line L1 .

[0175] In this embodiment, the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 is determined using the first theoretical wedge angle fitting line L1, thereby reducing the secondary image phenomenon projected by the laminated glass 10 in the projection display area 11 when viewed from the eye box plane EB10. Specifically, by selecting and designing the virtual image plane TB10, the distribution of the multiple theoretical wedge angle values ​​in the projection display area 11 of the laminated glass 10 can be calculated, and the first theoretical wedge angle fitting line L1 corresponding to the projection display area 11 can be fitted to determine the wedge angle value of the laminated glass 10 in the corresponding projection display area 11.

[0176] The design method for a head-up display system 1 provided in an embodiment of the present application reduces the local dispersion of the multiple theoretical wedge angle values ​​required for eliminating secondary images in the projection display area 11 by tilting the upper virtual image surface TB112 and / or the lower virtual image surface TB113 of at least one sub-virtual image surface TB11 toward the direction of viewing the corresponding sub-virtual image surface TB11 from the sub-eyebox surface EB11, with a forward tilt angle greater than or equal to 45°. This reduces the local dispersion of the multiple theoretical wedge angle values ​​required for eliminating secondary images in the projection display area 11, thereby converging the distribution of the multiple theoretical wedge angle values ​​toward the first theoretical wedge angle fitting line L1. This reduces the local extreme differences in the multiple theoretical wedge angle values, thereby improving the effectiveness of the head-up display system 1 in eliminating secondary images. Furthermore, the upper virtual image surface TB112 and / or the lower virtual image surface TB113 of the at least one sub-virtual image surface TB11 are approximately flat on the ground, providing the driver with a greater sense of ground contact and augmented reality when viewing the projected image 114, thereby enhancing the driving experience.

[0177] Referring again to FIG. 5 , in this embodiment, the "design of a virtual image plane TB10 tilted toward the direction of the corresponding sub-virtual image plane TB11 as viewed from the sub-eyebox plane EB11, based on the projected image 114 observed by an observer in the vehicle through each projection display area 11" includes designing at least one sub-virtual image plane TB11 tilted toward the direction of the corresponding sub-virtual image plane TB11 as viewed from the sub-eyebox plane EB11, with a forward tilt angle greater than or equal to 45°. FIG. 5 illustrates the sub-virtual image plane TB11 as being concave toward the ground. It is understood that FIG. 5 does not limit the shape of the sub-virtual image plane TB11.

[0178] On the principal optical axis plane, the forward tilt angle α0 of at least one of the multiple sub-virtual image planes TB11 is greater than or equal to 45°, or greater than or equal to 60°, or greater than or equal to 75°, or equal to 90° (to achieve ground alignment), thereby achieving an overall forward tilt of the projected image 114 and significantly improving the secondary image phenomenon in the projection display area 11. Furthermore, in some special scenarios, the forward tilt angle α0 of at least one of the sub-virtual image planes is greater than 90° and less than or equal to 95°.

[0179] Referring again to FIG. 3 , in this embodiment, the intersection line between the principal optical axis plane and the corresponding sub-virtual image plane TB11 has a vertex and a base. The distance between the vertex of the sub-virtual image plane TB11 and the center point of the corresponding sub-eyebox plane EB11 is VID1, and the distance between the base of the sub-virtual image plane TB11 and the center point of the corresponding sub-eyebox plane EB11 is VID2. The "virtual image plane TB10 is designed to be tilted toward the direction from the sub-eyebox plane EB11 to the corresponding sub-virtual image plane TB11 according to the projected image 114 observed by an observer in the vehicle through each projection display area 11" includes the following: when the upper virtual image plane TB112 and / or the lower virtual image plane TB113 of the sub-virtual image plane TB11 are tilted toward the direction from the sub-eyebox plane EB11 to the corresponding sub-virtual image plane TB11, VID1>VID2, thereby improving the projected secondary image.

[0180] 3 and 7 , in this embodiment, the upper virtual image plane TB112 and / or the lower virtual image plane TB113 of the sub-virtual image plane TB11 are tilted toward the direction of observing the corresponding sub-virtual image plane TB11 from the sub-eye box plane EB11 , and VID1 / VID2 ≥ 1.5.

[0181] On the principal optical axis plane (see FIG3 ), the angle between the line connecting the center point of the sub-eyebox surface EB11 and the center point of the corresponding sub-virtual image surface TB11 and the ground is the lower viewing angle LDA. When the center point of the sub-virtual image surface TB11 is below the center point of the sub-eyebox surface EB11, the lower viewing angle LDA is negative, and vice versa. The angle between the line connecting the center point of the sub-eyebox surface EB11 and the vertex of the corresponding sub-virtual image surface TB11, and the line connecting the center point of the sub-eyebox surface EB11 and the base of the corresponding sub-virtual image surface TB11 is the vertical field of view angle VFOV.

[0182] Taking the lower viewing angle LDA = -1.5 / -2.5 / -3.5 / -4.5 degrees and the vertical field of view VFOV = 2.5 / 3.0 / 3.5 / 4.0 / 4.5 / 5.0 / 5.5 / 6.0 degrees as an example (see Figure 7), the relationship between VID1 / VID2 and the forward tilt angle of the sub-virtual image plane TB11 is simulated and calculated. The horizontal axis represents the forward tilt angle of the sub-virtual image plane TB11, and the vertical axis represents VID1 / VID2. Each line represents the case where the lower viewing angle LDA corresponds to the vertical field of view VFOV. The simulation results show that the larger the vertical field of view VFOV, the larger the ratio of VID1 to VID2, thereby eliminating the scattered distribution of multiple theoretical wedge angle values ​​for the projected secondary image, and the more obvious the improvement effect of the corresponding secondary image.

[0183] In addition, when the lower viewing angle LDA is constant, the greater the forward tilt angle of the sub-virtual image plane TB11 is, the greater the ratio of VID1 / VID2 is, and the more obvious the improvement effect of the corresponding secondary image is.

[0184] In addition, when VID1 / VID2≥1.5, the corresponding forward tilt angle of the sub-virtual image plane TB11 is greater than or equal to 75°, the improvement effect of the corresponding secondary image is more obvious, and it can also bring a better sense of ground contact and reality enhancement.

[0185] Please refer to Figure 14 again. In this embodiment, the "virtual image plane TB10 is designed to be inclined toward the direction of the corresponding sub-virtual image plane TB11 observed from the sub-eye box surface EB11 based on the projection image 114 observed by the observer in the car through each projection display area 11" includes designing the angle between two adjacent sub-virtual image planes TB11 among the multiple sub-virtual image planes TB11 to be less than or equal to 15°.

[0186] In this embodiment, the angle between two adjacent sub-virtual image surfaces TB11 among the multiple sub-virtual image surfaces TB11 is less than or equal to 15°, preferably less than or equal to 10°, more preferably less than or equal to 5°, and more preferably less than or equal to 2°. Since, among the multiple sub-virtual image surfaces TB11, the sub-virtual image surface TB11 located in the middle of the multiple sub-virtual image surfaces TB11 serves as an interface. Since the local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the projection secondary image in the projection display area 11 corresponding to the multiple sub-virtual image surfaces TB11 increases from the interface upward, the local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the projection secondary image in the projection display area 11 corresponding to the multiple sub-virtual image surfaces TB11 also increases from the interface downward. Therefore, the forward tilt angle of the sub-virtual image plane TB11 gradually increases from the interface upward, and the forward tilt angle of the sub-virtual image plane TB11 gradually increases from the interface downward. This results in a smaller local discrete distribution of the multiple theoretical wedge angle values ​​required to eliminate the projected secondary image in the projection display area 11 corresponding to the multiple sub-virtual image planes TB11, and a convergence of the distribution of the multiple theoretical wedge angle values ​​toward the first theoretical wedge angle fitting line L1. That is, the local extreme values ​​of the multiple theoretical wedge angle values ​​are smaller, which can better improve the projected secondary image problem of the projected image 114 observed on the multiple sub-eye box planes EB11. To ensure that the driver has a consistent imaging experience when observing the projected image 114 at different heights in the cab, the angle between two adjacent sub-virtual image planes TB11 among the multiple sub-virtual image planes TB11 is less than or equal to 15°, preferably less than or equal to 10°, more preferably less than or equal to 5°, and more preferably less than or equal to 2°, thereby improving the driving experience.

[0187] Among them, the angle between two adjacent sub-virtual image surfaces TB11 refers to the angle between the extension line of the line connecting the vertex and the bottom point of one of the two adjacent sub-virtual image surfaces TB11 and the extension line of the line connecting the vertex and the bottom point of the other sub-virtual image surface TB11 on the main optical axis plane.

[0188] Referring again to FIG. 15 , in this embodiment, the ratio of the maximum local range ΔW of the plurality of theoretical wedge angle values ​​to the overall range ΔC of the plurality of theoretical wedge angle values ​​is: ΔW / ΔC≤0.9.

[0189] The ratio of the maximum local range ΔW of the multiple theoretical wedge angle values ​​to the overall range ΔC of the multiple theoretical wedge angle values ​​is: ΔW / ΔC ≤ 0.9. This can reduce the dispersion of the multiple theoretical wedge angle values ​​to increase the smoothness of the theoretical wedge angle fitting line, that is, reduce the slope of the theoretical wedge angle fitting line, thereby reducing the wedge angle change rate of the laminated glass 10 and reducing the difficulty of producing the laminated glass 10. It should be noted that the maximum local range ΔW of the multiple theoretical wedge angle values ​​refers to the maximum value among the local range values, wherein the local range value is the difference between the maximum and minimum values ​​among the multiple theoretical wedge angle values ​​at a position at a distance X from the bottom edge 12 of the glass of the laminated glass 10. The overall range ΔC of the multiple theoretical wedge angle values ​​refers to the difference between the maximum and minimum values ​​among all the theoretical wedge angle values.

[0190] Referring to Figures 9, 13, and 16, in this embodiment, the at least one projection display area 11 includes at least two first projection display areas 115 or at least two second projection display areas 116. At least two first theoretical wedge angle fitting lines L1 are fitted to obtain the wedge angle as a function of the distance from the incident point to the bottom edge 12 of the glass. When the maximum deviation ΔXmax between two adjacent first theoretical wedge angle fitting lines L1 is greater than 0.15 mrad, after determining the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 based on the first theoretical wedge angle fitting line L1, the design method of the head-up display system 1 further includes adjusting the distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1. New theoretical wedge angle values ​​are recalculated. Based on these new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the glass corresponding to each theoretical wedge angle value, a second theoretical wedge angle fitting line L2 is fitted to obtain the wedge angle as a function of the distance from the incident point to the bottom edge 12 of the glass. Then, determine whether the maximum deviation ΔXmax between the second theoretical wedge angle fitting line L2 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.15 mrad. If not, repeat the above steps. If so, determine the wedge angle value of the laminated glass 10 in the corresponding first projection display area 115 or second projection display area 116 based on the second theoretical wedge angle fitting line L2.

[0191] In this embodiment, when two adjacent first theoretical wedge angle fitting lines L1 have an overlapping part, the maximum deviation value △Xmax is equal to the maximum value of the difference between the two first theoretical wedge angle fitting lines L1 in the overlapping part; when two adjacent first theoretical wedge angle fitting lines L1 do not have an overlapping part, the maximum deviation value △Xmax is equal to the difference between the wedge angle values ​​at the two most adjacent ends of the two first theoretical wedge angle fitting lines L1.

[0192] When the maximum deviation value △Xmax is greater than 0.15 mrad, it is necessary to adjust the distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to any one of the two adjacent first theoretical wedge angle fitting lines L1, so as to adjust the maximum deviation value △Xmax between the designed first theoretical wedge angle fitting line L1 and the adjusted second theoretical wedge angle fitting line L2 to less than or equal to 0.15 mrad, or less than or equal to 0.10 mrad, or less than or equal to 0.08 mrad, or less than or equal to 0.05 mrad.

[0193] Specifically, after “determining the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 according to the first theoretical wedge angle fitting line L1 ,” at least one of two adjacent first theoretical wedge angle fitting lines L1 needs to be adjusted.

[0194] The distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1 is adjusted.

[0195] The wedge angle required to eliminate the projected secondary image can be adjusted by adjusting the distance between the eyebox surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1. Under the same conditions, the greater the distance between the eyebox surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1, the smaller the wedge angle required to eliminate the projected secondary image. In this embodiment, the distance between the virtual image surface TB10 corresponding to one of the first theoretical wedge angle fitting lines L1 and the eyebox surface EB10 can be increased, and / or the distance between the virtual image surface TB10 corresponding to the other first theoretical wedge angle fitting line L1 and the eyebox surface EB10 can be decreased, so that the two adjacent first theoretical wedge angle fitting lines L1 are closer to the design target.

[0196] A plurality of new theoretical wedge angle values ​​are recalculated.

[0197] In this embodiment, after adjusting the distance between the virtual image plane TB10 and the eye box plane EB10 , the plurality of theoretical wedge angle values ​​calculated by the calculation method of the aforementioned embodiment can be used to fit a fitting line that is closer to the design target.

[0198] According to the multiple new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the glass corresponding to each theoretical wedge angle value, a second theoretical wedge angle fitting line L2 is obtained by fitting the wedge angle along the distance from the incident point to the bottom edge 12 of the glass.

[0199] It is determined whether a maximum deviation value ΔXmax between the second theoretical wedge angle fitting line L2 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.15 mrad.

[0200] In this embodiment, it is determined whether the maximum deviation ΔXmax between the second theoretical wedge angle fitting line L2 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.15 mrad. If not, the above adjustment steps are repeated. If so, the wedge angle value is selected.

[0201] The wedge angle value of the laminated glass 10 in the corresponding first projection display area 115 or the second projection display area 116 is determined according to the second theoretical wedge angle fitting line L2.

[0202] Referring to Figures 9, 13, and 17, in this embodiment, the at least one projection display area 11 includes at least one first projection display area 115 and at least one second projection display area 116. Fitting is performed to obtain at least two first theoretical wedge angle fitting lines L1, which show the wedge angle as a function of the distance from the incident point to the bottom edge 12 of the glass. When the maximum deviation ΔXmax between two adjacent first theoretical wedge angle fitting lines L1 is greater than 0.2 mrad, after determining the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 based on the first theoretical wedge angle fitting lines L1, the design method of the head-up display system 1 further includes adjusting the distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1. New theoretical wedge angle values ​​are recalculated. Based on these new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the glass corresponding to each theoretical wedge angle value, a third theoretical wedge angle fitting line L3, which shows the wedge angle as a function of the distance from the incident point to the bottom edge 12 of the glass, is fitted. Then, determine whether the maximum deviation ΔXmax between the third theoretical wedge angle fitting line L3 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.15 mrad. If not, repeat the above steps. If so, determine the wedge angle value of the laminated glass 10 in the corresponding first projection display area 115 or second projection display area 116 based on the third theoretical wedge angle fitting line L3.

[0203] In this embodiment, when two adjacent first theoretical wedge angle fitting lines L1 have an overlapping part, the maximum deviation value △Xmax is equal to the maximum value of the difference between the two first theoretical wedge angle fitting lines L1 in the overlapping part; when two adjacent first theoretical wedge angle fitting lines L1 do not have an overlapping part, the maximum deviation value △Xmax is equal to the difference between the wedge angle values ​​at the two most adjacent ends of the two first theoretical wedge angle fitting lines L1.

[0204] When the maximum deviation value △Xmax is greater than 0.2 mrad, it is necessary to adjust the distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to any one of the two adjacent first theoretical wedge angle fitting lines L1, so as to adjust the maximum deviation value △Xmax between the designed first theoretical wedge angle fitting line L1 and the adjusted second theoretical wedge angle fitting line L2 to less than or equal to 0.2 mrad, or less than or equal to 0.15 mrad, or less than or equal to 0.10 mrad, or less than or equal to 0.08 mrad, or less than or equal to 0.05 mrad.

[0205] Specifically, after “determining the wedge angle value of the laminated glass 10 in the corresponding projection display area 11 according to the first theoretical wedge angle fitting line L1 ,” at least one of two adjacent first theoretical wedge angle fitting lines L1 needs to be adjusted.

[0206] The distance between the eye box surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1 is adjusted.

[0207] The wedge angle required to eliminate the projected secondary image can be adjusted by adjusting the distance between the eyebox surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1. Under the same conditions, the greater the distance between the eyebox surface EB10 and the virtual image surface TB10 corresponding to one of the two adjacent first theoretical wedge angle fitting lines L1, the smaller the wedge angle required to eliminate the projected secondary image. In this embodiment, the distance between the virtual image surface TB10 corresponding to one of the first theoretical wedge angle fitting lines L1 and the eyebox surface EB10 can be increased, and / or the distance between the virtual image surface TB10 corresponding to the other first theoretical wedge angle fitting line L1 and the eyebox surface EB10 can be decreased, so that the two adjacent first theoretical wedge angle fitting lines L1 are closer to the design target.

[0208] A plurality of new theoretical wedge angle values ​​are obtained by recalculation.

[0209] In this embodiment, after adjusting the distance between the virtual image plane TB10 and the eye box plane EB10 , the plurality of theoretical wedge angle values ​​calculated by the calculation method of the aforementioned embodiment can be used to fit a fitting line that is closer to the design target.

[0210] According to the multiple new theoretical wedge angle values ​​and the distance from the incident point to the bottom edge 12 of the glass corresponding to each theoretical wedge angle value, a third theoretical wedge angle fitting line L3 is obtained, which shows the wedge angle changing with the distance from the incident point to the bottom edge 12 of the glass.

[0211] It is determined whether a maximum deviation value ΔXmax between the third theoretical wedge angle fitting line L3 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.2 mrad.

[0212] In this embodiment, it is determined whether the maximum deviation ΔXmax between the third theoretical wedge angle fitting line L3 and the other of the two adjacent first theoretical wedge angle fitting lines L1 is less than or equal to 0.2 mrad. If not, the above adjustment steps are repeated. If so, the wedge angle value is selected.

[0213] The wedge angle value of the laminated glass 10 in the corresponding first projection display area 115 or the second projection display area 116 is determined according to the third theoretical wedge angle fitting line L3.

[0214] Please refer to Figure 18. In this embodiment, the new multiple theoretical wedge angle values ​​and the collection of the multiple theoretical wedge angle values ​​have a maximum local range value △WU, the new multiple theoretical wedge angle values ​​and the collection of the multiple theoretical wedge angle values ​​have an overall range value △CU, and the ratio of △WU to △CU is: △WU / △CU≤0.9.

[0215] In this embodiment, after adjustment, the set of the multiple theoretical wedge angle values ​​corresponding to the first projection display area 115 and the multiple theoretical wedge angle values ​​corresponding to the second projection display area 116 has a maximum local range value ΔWU and an overall range value ΔCU, and the ratio of ΔWU to ΔCU is: ΔWU / ΔCU ≤ 0.9. This can reduce the overall dispersion of the multiple theoretical wedge angle values ​​after adjustment, thereby increasing the smoothness of the first theoretical wedge angle fitting line L1 and the third theoretical wedge angle fitting line L3. In other words, the overall slope of the first theoretical wedge angle fitting line L1 and the third theoretical wedge angle fitting line L3 is reduced, thereby reducing the overall wedge angle variation rate of the laminated glass 10 and reducing the difficulty in producing the laminated glass 10. It should be noted that the maximum local range value ΔWU of the set of multiple theoretical wedge angle values ​​refers to the maximum value among the local range values ​​of the set, where the local range value of the set is the difference between the maximum and minimum values ​​of the set of multiple theoretical wedge angle values ​​at a location at a distance X from the bottom edge 12 of the laminated glass 10. The set of the plurality of theoretical wedge angle values ​​has an overall range value ΔCU, which refers to the difference between the maximum value and the minimum value in the set of all theoretical wedge angle values.

[0216] Please refer to Figures 19, 20, 21, and 22. In one embodiment of the present application, the at least one projection display area 11 includes a first projection display area 115 for schematic illustration. The first projection display area 115 corresponds to the AR-HUD, and the projection display distance is 10,000 mm.

[0217] The laminated glass 10 includes a first transparent substrate 14, an intermediate adhesive layer 16, and a second transparent substrate 15. The thickness of the first transparent substrate 14 is 1.8 mm, the minimum thickness of the intermediate adhesive layer 16 is 0.76 mm, and the thickness of the second transparent substrate 15 is 1.8 mm. When the laminated glass 10 is installed on a vehicle's windshield, the vehicle installation angle is 27°. The vertical curvature of the first projection display area 115 is R5400 mm to R5500 mm, and the lateral curvature is R2500 mm to R2550 mm.

[0218] The dimensions of the eyebox surface EB10 are 120 mm x 50 mm. For a schematic illustration, the eyebox surface EB10 includes three sub-eyebox surfaces EB11 arranged in descending order. The center points of two adjacent sub-eyebox surfaces EB11 are 40 mm apart. The downward viewing angles of the three sub-eyebox surfaces EB11, from highest to lowest, are -4.2 degrees, -2.6 degrees, and -1.0 degrees, respectively. The horizontal viewing angles are all 0 degrees, and the field of view angles are all 10 degrees x 4 degrees. The distance from the center point of the middle sub-eyebox surface EB11 among the three sub-eyebox surfaces EB11 to the intersection of the principal optical axis of the first projection light source 211 and the surface of the laminated glass 10 near the interior of the vehicle is 826 mm, and the incident angle of the first projection light source 211 is 68 degrees.

[0219] The observation dot matrices EB111m×n on the three sub-eye box surfaces EB11 are all 5×3 dot matrices (see Figure 19), and the virtual image dot matrices TB111i×j on the three sub-virtual image planes TB11 corresponding to the three sub-eye box surfaces EB11 are all 5×3.

[0220] In the first embodiment, the front tilt angle of the virtual image plane is 2.6 degrees. In the second embodiment, the front tilt angle of the virtual image plane is 88 degrees.

[0221] According to the design method of the head-up display system 1 described in the aforementioned embodiment, the theoretical wedge angle values ​​for eliminating the secondary image projected on the first projection display area 115 in the first and second embodiments are calculated and generated as scatter plots. Taking the scatter plot generated by corresponding points on the perpendicular bisector of the middle sub-eye box EB11 among the three sub-eye boxes EB11 described in the first embodiment as an example (see FIG. 20 ), EB_Rm corresponds to a point on the perpendicular bisector of the sub-eye box EB11, and RiCj represents a point on the sub-virtual image plane TB11. The combination of EB_Rm and RiCj represents the theoretical wedge angle value when observing point RiCj from point RiCj without a secondary image. Here, m = 1, 2, 3, 4, 5. Here, i = 1, 2, 3, 4, 5; and j = 1, 2, 3. Furthermore, the scatter point distribution pattern of the theoretical wedge angle values ​​of the sub-virtual image surface TB11 without a secondary image observed from the perpendicular bisector of the other sub-eyebox surfaces EB11 in the first embodiment is the same as that in FIG20 , and the resulting scatter point distribution can be calculated. Furthermore, the scatter point distribution pattern of the theoretical wedge angle values ​​of the virtual image surface TB10 without a secondary image observed from points on a line parallel to the perpendicular bisector of the eyebox surface EB10 is approximately the same as that in FIG20 , and the resulting scatter point distribution can be calculated as shown in the dashed box in FIG21 .

[0222] In the second embodiment (see FIG21 ), the scatter distribution of theoretical wedge angle values ​​for a secondary image-free sub-virtual image surface TB11 observed from points on the perpendicular bisector of the sub-eyebox surface EB11 tends to converge more towards the dashed line segment within the dashed frame, compared to the first embodiment. The dashed line segment within the dashed frame represents the line connecting the multiple theoretical wedge angle values ​​for a secondary image-free sub-virtual image surface TB11 center point observed from points on the perpendicular bisector of the sub-eyebox surface EB11. Furthermore, the scatter distribution pattern of theoretical wedge angle values ​​for a secondary image-free virtual image surface TB10 observed from points on a line parallel to the perpendicular bisector of the eyebox surface EB10 is approximately the same as that in FIG20 , and the outline of the scatter distribution can be calculated as shown in the solid frame in FIG21 .

[0223] Finally, the first and second embodiments can calculate a total of 1350 theoretical wedge angle values ​​(see FIG22 ). Specific comparisons are shown in the following table.

[0224]

[0225] In the table, △C represents the difference between the maximum and minimum values ​​in the set of multiple theoretical wedge angle values ​​corresponding to no secondary image projected on the laminated glass 10. △C1 is the difference between the maximum and minimum values ​​in the set of multiple theoretical wedge angle values ​​corresponding to no secondary image projected on the laminated glass 10 in the first embodiment. △C2 is the difference between the maximum and minimum values ​​in the set of multiple theoretical wedge angle values ​​corresponding to no secondary image projected on the laminated glass 10 in the second embodiment. △W represents the maximum value in the local extreme difference values ​​of the set of multiple theoretical wedge angle values ​​corresponding to no secondary image projected on the laminated glass 10. The local extreme difference value of the set is the difference between the maximum and minimum values ​​in the set of multiple theoretical wedge angle values ​​at a certain position at a distance X from the bottom edge 12 of the glass of the laminated glass 10. In addition, compared with the first embodiment, the second embodiment has the maximum difference in △W at a distance of about 520 mm from the bottom edge 12 of the glass, and the △W of the first embodiment here is named △W before In the second embodiment, ΔW is ΔW after .

[0226] For HUDs, the secondary image value indicates the severity of the projected secondary image, with a secondary image value of 0 indicating no projected secondary image. The maximum local extreme difference ΔW is proportional to the secondary image value: smaller ΔW indicates smaller secondary image values, and the change in ΔW corresponds to the change in secondary image value. As shown in the table above, the change in ΔW / ΔC in the second embodiment compared to the first embodiment, i.e., after the virtual image plane TB10 is tilted forward, is 21.1%. ΔW / ΔC reflects the improvement in secondary image value achieved with a variable wedge angle compared to a fixed wedge angle. Specifically, the smaller the ΔW / ΔC ratio, the more suitable the variable wedge angle. Therefore, the change in ΔW / ΔC is 21.1%, indicating that the second embodiment is more suitable for a variable wedge angle than the first embodiment, with an improvement of 21.1%.

[0227] In addition, △W before to △W after The improvement rate is 18.6%, which indicates the improvement degree of the maximum local extreme difference value ΔW after the virtual image surface TB10 is tilted forward.

[0228] In addition, △W before / △C to △W after The improvement rate of / ΔC is 20.8%, which indicates the improvement of the secondary image value corresponding to the variable wedge angle relative to the fixed wedge angle after the virtual image plane TB10 is tilted forward.

[0229] In summary, by comparing the second embodiment with the first embodiment, it can be concluded that, from multiple indicators, the forward tilt setting of the virtual image plane TB10 and the variable wedge angle of the laminated glass 10 can bring about a greater improvement in the secondary image.

[0230] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application, and these improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A head-up display system, characterized in that, The head-up display system includes: Laminated glass, the laminated glass having at least one projection display area, each of the projection display areas having a wedge-shaped cross-section where the upper side thickness is greater than the lower side when the laminated glass is installed in a vehicle, and having a section where the wedge angle continuously decreases from the lower side to the upper side; A projection assembly, comprising at least one projection light source capable of projecting onto the at least one projection display area, wherein projection light emitted from the projection light source is incident on the projection display area to form a projected image, the projected image having a virtual image surface; and An eye box having an eye box surface through which the projected image can be viewed; The eye box surface includes multiple sub-eye box surfaces, and the virtual image surface includes multiple sub-virtual image surfaces corresponding to the multiple sub-eye box surfaces. Each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface. The upper virtual image surface and / or the lower virtual image surface of at least one of the sub-virtual image surfaces is tilted toward the direction from which the corresponding sub-virtual image surface is viewed from the sub-eye box surface, and its forward tilt angle is greater than or equal to 45°.

2. The head-up display system as described in claim 1, characterized in that, At least one of the upper and / or lower virtual image planes of the sub-virtual image planes is tilted toward the direction of the corresponding sub-virtual image plane as viewed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 75°.

3. The head-up display system as described in claim 1, characterized in that, At least one of the said virtual image planes is tilted toward the direction of the corresponding virtual image plane as viewed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 45°.

4. The head-up display system as described in claim 1, characterized in that, At least one of the said virtual image planes is tilted toward the direction of the corresponding virtual image plane as viewed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 75°.

5. The head-up display system as described in claim 1, characterized in that, The distance between the vertex of the virtual image plane and the center point of the corresponding sub-eyebox is VID1, and the distance between the bottom point of the virtual image plane and the center point of the corresponding sub-eyebox is VID2, where VID1 > VID2.

6. The head-up display system as described in claim 5, characterized in that, VID1 / VID2≥1.

5.

7. The head-up display system as described in claim 1, characterized in that, At any point within the segment, there are multiple theoretical wedge angle values ​​for measuring the wedge angle and eliminating secondary images. The measured wedge angles at each point within the segment are fitted to obtain an actual wedge angle fitting line. The multiple theoretical wedge angle values ​​at each point within the segment are fitted to obtain a first theoretical wedge angle fitting line. The maximum deviation between the actual wedge angle fitting line and the first theoretical wedge angle fitting line is less than or equal to 0.07 mrad.

8. The head-up display system as described in claim 7, characterized in that, Both the actual wedge angle fitting line and the first theoretical wedge angle fitting line conform to a polynomial function.

9. The head-up display system as described in claim 8, characterized in that, The maximum rate of change (ROC) at which the wedge angle continuously and monotonically decreases within the specified section is: ROC ≤ 0.3 mrad / 100 mm; or, ROC ≤ 0.2 mrad / 100 mm; or, ROC ≤ 0.1 mrad / 100 mm; or, ROC ≤ 0.05 mrad / 100 mm.

10. The head-up display system as claimed in claim 1, characterized in that, The included angle between two adjacent virtual image planes in the plurality of virtual image planes is less than or equal to 15°.

11. The head-up display system as claimed in claim 1, characterized in that, In the direction from the bottom edge of the laminated glass to the top edge of the glass, the ratio of the length of the segment to the length of the projection display area is not less than 70%.

12. The head-up display system as claimed in claim 1, characterized in that, The at least one projection display area includes: At least one first projection display area, wherein the projection light source is incident on the first projection display area to form a first projection image, and the virtual image distance of the first projection image is 7 meters to 100 meters; and At least one second projection display area, wherein the projection light source is incident on the second projection display area to form a second projection image, and the virtual image distance of the second projection image is 1 meter to 6 meters.

13. The head-up display system as described in claim 12, characterized in that, The at least one projection light source includes at least one first projection light source and at least one second projection light source, wherein the first projection light source is incident on the first projection display area and the second projection light source is incident on the second projection display area.

14. The head-up display system as claimed in claim 1, characterized in that, The laminated glass comprises: First transparent substrate; Second transparent substrate; and An intermediate adhesive layer is disposed between the first transparent substrate and the second transparent substrate for bonding the first transparent substrate and the second transparent substrate; At least one of the first transparent substrate, the second transparent substrate, and the intermediate adhesive layer has a wedge angle in the projection display area.

15. The head-up display system as described in claim 14, characterized in that, The first transparent substrate and the second transparent substrate both have a wedge angle of 0 in the projection display area, and the intermediate adhesive layer has a wedge angle in the projection display area, which is equal to the wedge angle of the projection display area.

16. The head-up display system as described in claim 14, characterized in that, The first transparent substrate and / or the second transparent substrate have a wedge angle in the projection display area, the intermediate adhesive layer has a wedge angle in the projection display area, and the sum of the wedge angles of the first transparent substrate and / or the second transparent substrate in the projection display area and the wedge angle of the intermediate adhesive layer in the projection display area is equal to the wedge angle of the projection display area.

17. A design method for a head-up display system, characterized in that, The design method of the head-up display system includes: A projection assembly and a laminated glass are provided, wherein the projection light emitted by the projection assembly is incident on at least one projection display area on the laminated glass; The eye box surface inside the vehicle is designed based on the observer inside the vehicle; The virtual image surface is designed to be tilted in the direction of the corresponding virtual image surface observed from the sub-eye box surface, based on the projected image observed by the observer inside the vehicle through each projection display area. The eye box surface includes multiple sub-eye box surfaces, and the virtual image surface includes multiple sub-virtual image surfaces. Each sub-virtual image surface corresponds to one sub-eye box surface. Each sub-virtual image surface includes an upper virtual image surface and a lower virtual image surface. At least one of the upper and / or lower virtual image surfaces of the sub-virtual image surface is tilted toward the direction from which the corresponding sub-virtual image surface is viewed from the sub-eye box surface, and its forward tilt angle is greater than or equal to 45°. An observation dot matrix is ​​selected on each sub-eye box surface, and a virtual image dot matrix is ​​selected on each sub-virtual image surface. The line connecting the points in the observation dot matrix and the points in the virtual image dot matrix passes through the corresponding projection display area, and the intersection of the line and the projection display area is the incident point. Calculate multiple theoretical wedge angle values ​​of the laminated glass when the projected image at the corresponding incident point position has no secondary image based on the projection component, laminated glass, and multiple connecting lines. Based on the plurality of theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the laminated glass corresponding to each theoretical wedge angle value, a first theoretical wedge angle fitting line is obtained by fitting the wedge angle as a function of the distance from the incident point to the bottom edge of the glass; and The wedge angle value of the laminated glass in the corresponding projection display area is determined based on the first theoretical wedge angle fitting line.

18. The design method of the head-up display system as described in claim 17, characterized in that, The phrase "designing a virtual image surface tilted towards the direction of the corresponding virtual image surface observed from the sub-eye box surface, based on the projected image observed by an observer inside the vehicle through each projection display area" includes: At least one of the virtual image planes is designed to face the direction of the corresponding virtual image plane as viewed from the sub-eye box plane, and its forward tilt angle is greater than or equal to 45°.

19. The design method of the head-up display system as described in claim 17, characterized in that, The phrase "designing a virtual image surface tilted towards the direction of the corresponding virtual image surface observed from the sub-eye box surface, based on the projected image observed by an observer inside the vehicle through each projection display area" includes: When the upper virtual image plane and / or the lower virtual image plane of the sub-virtual image plane are tilted toward the direction of the corresponding sub-virtual image plane as viewed from the sub-eye box plane, VID1 > VID2; Wherein, the distance between the vertex of the virtual image plane and the center point of the corresponding sub-eyebox plane is VID1, and the distance between the bottom point of the virtual image plane and the center point of the corresponding sub-eyebox plane is VID2.

20. The design method of the head-up display system as described in claim 19, characterized in that, VID1 / VID2≥1.

5.

21. The design method of the head-up display system as described in claim 17, characterized in that, The phrase "designing a virtual image surface tilted towards the direction of the corresponding virtual image surface observed from the sub-eye box surface, based on the projected image observed by an observer inside the vehicle through each projection display area" includes: The angle between any two adjacent virtual image planes in the plurality of virtual image planes is designed to be less than or equal to 15°.

22. The design method of the head-up display system as described in claim 17, characterized in that, The ratio of the maximum local range ΔW of the plurality of theoretical wedge angle values ​​to the global range ΔC of the plurality of theoretical wedge angle values ​​is: ΔW / ΔC≤0.

9.

23. The design method of the head-up display system as described in claim 17, characterized in that, The at least one projection display area includes at least two first projection display areas or at least two second projection display areas. At least two first theoretical wedge angle fitting lines are obtained by fitting the wedge angle as a function of the distance from the incident point to the bottom edge of the glass. When the maximum deviation between two adjacent first theoretical wedge angle fitting lines is greater than 0.15 mrad, after "determining the wedge angle value of the laminated glass in the corresponding projection display area based on the first theoretical wedge angle fitting lines," the design method of the head-up display system further includes: Adjust the distance between the eye box surface and the virtual image surface corresponding to one of the two adjacent first theoretical wedge angle fitting lines; The new theoretical wedge angle values ​​were recalculated. Based on the new multiple theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass corresponding to each theoretical wedge angle value, a second theoretical wedge angle fitting line is obtained by fitting the wedge angle as a function of the distance from the incident point to the bottom edge of the glass; and Determine whether the maximum deviation between the second theoretical wedge angle fitting line and the other of the two adjacent first theoretical wedge angle fitting lines is less than or equal to 0.15 mrad; If not, repeat the above steps; If so, the wedge angle value of the laminated glass in the corresponding first projection display area or second projection display area is determined according to the second theoretical wedge angle fitting line.

24. The design method of the head-up display system as described in claim 17, characterized in that, The at least one projection display area includes at least one first projection display area and at least one second projection display area. At least two first theoretical wedge angle fitting lines are obtained by fitting the wedge angle as a function of the distance from the incident point to the bottom edge of the glass. When the maximum deviation between two adjacent first theoretical wedge angle fitting lines is greater than 0.2 mrad, after "determining the wedge angle value of the laminated glass in the corresponding projection display area based on the first theoretical wedge angle fitting lines", the design method of the head-up display system further includes: Adjust the distance between the eye box surface and the virtual image surface corresponding to one of the two adjacent first theoretical wedge angle fitting lines; The new theoretical wedge angle values ​​were recalculated. Based on the new multiple theoretical wedge angle values ​​and the distance from the incident point to the bottom edge of the glass corresponding to each theoretical wedge angle value, a third theoretical wedge angle fitting line is obtained by fitting the wedge angle as a function of the distance from the incident point to the bottom edge of the glass; and Determine whether the maximum deviation between the third theoretical wedge angle fitting line and the other of the two adjacent first theoretical wedge angle fitting lines is less than or equal to 0.15 mrad; If not, repeat the above steps; If so, the wedge angle value of the laminated glass in the corresponding first projection display area or second projection display area is determined according to the third theoretical wedge angle fitting line.

25. The design method of the head-up display system as described in claim 17, characterized in that, The adjusted set of multiple theoretical wedge angle values ​​has a maximum local range ΔWU and an overall range ΔCU. The ratio of ΔWU to ΔCU is: ΔWU / ΔCU ≤ 0.9.

Images