Laminated glass, projection system, and vehicle

Abstract

This application provides laminated glass, a projection system, and a vehicle. The laminated glass includes a first glass plate, an intermediate adhesive layer, a second glass plate, and an adjustment layer. The laminated glass has a wedge shape. When the proportion of S-polarized light in the projected light is ≥90% and the incident angle β of the projected light is >65°, the brightness ratio RR12 of the primary and secondary images of the laminated glass is ≥12.5. This application not only reduces the ghosting separation between the reflected primary and secondary images by setting a wedge shape, but also converts S-polarized light into P-polarized light by setting an adjustment layer. Combined with the high proportion of S-polarized light in the projected light and the high incident angle, the reflected secondary image is dimmed. The laminated glass has a high brightness ratio RR12, thereby achieving synergy with the head-up display system. By utilizing the visual masking effect in visual perception, the user can observe a clear display image, improving driving safety.

Description

Technical Field

[0001] This application belongs to the field of laminated glass technology, specifically relating to laminated glass, projection systems, and vehicles. Background Technology

[0002] With the application of vehicle head-up displays (HUDs), drivers can reduce the need to look down at the dashboard or related information, making it easier for them to switch their eyes between near and far objects. This reduces the need to look down at the dashboard, allowing drivers to concentrate their attention on the road and improving driving safety.

[0003] The HUD optical path is as follows: Image information is projected onto the image display area through a projection device. The projected light is reflected by the inner surface of the laminated glass and enters the human eye to form the primary image. However, since the laminated glass is a transparent medium, a secondary reflective ghost image, also known as a reflection ghost or reflection secondary image, is formed after reflection from the outer surface of the laminated glass into the human eye.

[0004] Due to factors such as car design and reducing overall wind resistance, some windshields have a more tilted angle and a smaller mounting angle, such as 25° for coupe models. Theoretically, the ghosting amount corresponding to the HUD light path in these models will be greater than that in regular models. Combined with manufacturing factors, the ghosting is even greater, the image is blurry, and the experience is poor. Summary of the Invention

[0005] In view of this, the first aspect of this application provides a laminated glass, the laminated glass comprising a first glass plate, an intermediate adhesive layer, and a second glass plate stacked sequentially; The first glass plate includes a first surface facing away from the intermediate adhesive layer and a second surface close to the intermediate adhesive layer; the second glass plate includes a third surface close to the intermediate adhesive layer and a fourth surface facing away from the intermediate adhesive layer. The laminated glass has an image display area for receiving and reflecting projected light to form a display image. The projected light forms a reflected primary image and a reflected secondary image as the display image. At least within the area of ​​the image display area, a wedge α is formed between the first surface and the fourth surface. The laminated glass also includes an adjustment layer located in the image display area. The adjustment layer is disposed between the first glass plate and the second glass plate. The adjustment layer is used to convert S-polarized light into P-polarized light. When the proportion of S-polarized light in the projected light is ≥90% and the incident angle β of the projected light is >65°, the laminated glass has a primary-to-secondary image brightness ratio RR12. The primary-to-secondary image brightness ratio RR12 is the brightness ratio of the reflected primary image to the reflected secondary image, and the primary-to-secondary image brightness ratio RR12 is ≥12.5.

[0006] The wedge α is used to ensure that the displacement difference between the secondary reflective image and the primary reflective image is within a preset range, wherein the preset range is ≤4.5arcmin.

[0007] Wherein, the wedge angle of the wedge α is ≤0.72mrad; And / or, the rate of change of the wedge angle of the wedge α is ≤0.3mrad / 100mm.

[0008] Wherein, the first glass plate and / or the second glass plate have a wedge angle, and the wedge angle of the first glass plate and / or the second glass plate has a first local wedge angle fluctuation standard deviation σ1 in the image display area, and the first local wedge angle fluctuation standard deviation σ1 satisfies the following condition: 3σ1≤0.08mrad / 10mm; And / or, the intermediate adhesive layer has a wedge angle, the wedge angle of the intermediate adhesive layer having a second local wedge angle fluctuation standard deviation σ2 within the image display area, the second local wedge angle fluctuation standard deviation σ2 satisfying the following condition: 3σ2≤0.15mrad / 10mm.

[0009] The first glass plate and / or the second glass plate with the wedge angle have a spray direction, which is vertical or horizontal.

[0010] Wherein, the conversion efficiency of the adjustment layer for the S-polarized light is ≥90%; And / or, the thickness of the adjustment layer is 2μm~200μm; And / or, the internal reflectivity of the adjustment layer in the laminated glass is ≤2%.

[0011] The adjustment layer is selected from half-wave plate film.

[0012] The half-wave plate film is selected from at least one of polyimide-based thin film half-wave plate, liquid crystal polymer thin film half-wave plate, indium tin oxide thin film half-wave plate, quartz-based flexible thin film half-wave plate, nanocomposite thin film half-wave plate, graphene-oxide composite thin film half-wave plate, and ultrathin dielectric metasurface half-wave plate.

[0013] The intermediate adhesive layer includes a first adhesive layer and a second adhesive layer, and the first glass plate, the first adhesive layer, the adjustment layer, the second adhesive layer, and the second glass plate are stacked in sequence.

[0014] The sum of the thicknesses of the first adhesive layer and the second adhesive layer is 0.38 mm to 2.28 mm.

[0015] Wherein, the thickness ratio K of the first adhesive layer to the second adhesive layer satisfies: K=1±0.5.

[0016] The image display area is also used to receive and transmit external light, which forms a main image TL1 and a secondary image TL2. The laminated glass has a primary-to-secondary image transmittance ratio TT12, which is the ratio of the visible light transmittance of the primary image TL1 to the secondary image TL2, and the primary-to-secondary image transmittance ratio TT12 ≥ 40.

[0017] The displayed image can be observed at the eye box, which includes an upper eye box, a middle eye box, and a lower eye box corresponding to each virtual image plane. The display image corresponding to the upper eye box is tilted away from the eye box. And / or, the display image corresponding to the eye box is tilted away from the eye box; And / or, the display image corresponding to the lower eyelid box is tilted away from the eyelid box.

[0018] The display image corresponding to the middle eye box is tilted away from the eye box, and the tilt angle γ of the display image corresponding to the middle eye box is ≥45°.

[0019] Wherein, the vertical field of view (VFOV) of the image display area is ≤5°.

[0020] Wherein, the square root Gaussian curvature SRG of the first glass plate and / or the second glass plate is ≤0.00025mm. -1 .

[0021] The incident angle β of the projected light ray satisfies the following condition: 65°<β≤75°.

[0022] Wherein, the thickness of the second glass plate is ≤2.1mm; And / or, at least within the area of ​​the image display area, the laminated glass is provided with a coloring material, the coloring material having a visible light transmittance of ≥50%, ≥60%, or ≥70%.

[0023] The second aspect of this application provides a projection system, which includes a projection device and a laminated glass as provided in the first aspect of this application. The projection device is disposed on the side of the second glass plate away from the intermediate adhesive layer. The projection device is used to generate projection light, which includes S-polarized light. The proportion of S-polarized light in the projection light is ≥90%. The image display area is used to receive and reflect the projection light to form a display image.

[0024] A third aspect of this application provides a vehicle comprising a body and a laminated glass as provided in the first aspect of this application, the laminated glass being disposed on the body.

[0025] The laminated glass, projection system, and vehicle provided in this application not only minimize the ghosting separation between the reflected primary image and the reflected secondary image by setting a wedge shape, but also convert S-polarized light into P-polarized light by setting an adjustment layer. Combined with the projection light with a high proportion of S-polarized light and a high incident angle, the reflected secondary image becomes dim. The laminated glass has a high primary-to-secondary image brightness ratio RR12, thereby achieving synergy with the head-up display system. By utilizing the visual masking effect in visual perception, the user can observe a clear display image, improving driving safety. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0027] Figure 1 This is a schematic diagram of the structure of laminated glass provided in one embodiment of this application.

[0028] Figure 2 This is a cross-sectional schematic diagram of laminated glass provided in one embodiment of this application.

[0029] Figure 3 A virtual image orientation diagram of laminated glass provided in one embodiment of this application.

[0030] Figure 4 The simulation results of the laminated glass in embodiments A1-A3 provided in this application are shown in the figure.

[0031] Figure 5 Simulation results of the laminated glass in embodiments B1-B5 provided in this application.

[0032] Figure 6 Virtual image pose diagrams of the laminated glass in Comparative Examples 1-2 and Examples 1-2 provided for this application.

[0033] Figure 7 The virtual image orientation diagram of the laminated glass in Embodiment 3 provided in this application.

[0034] Figure 8 The diagram showing the relationship between the wedge angle of the eye box and the maximum vertical ghosting amount in the comparative examples and embodiments provided in this application.

[0035] Labeling: laminated glass 1, image display area 10, first glass plate 11, intermediate adhesive layer 12, first adhesive layer 121, second adhesive layer 122, second glass plate 13, adjustment layer 14, projection device 21. Detailed Implementation

[0036] The following are preferred embodiments of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0037] In view of this, in order to solve the above problems, please refer to the following: Figures 1-2 This embodiment provides a laminated glass 1, which includes a first glass plate 11, an intermediate adhesive layer 12, and a second glass plate 13 stacked sequentially.

[0038] The first glass plate 11 includes a first surface facing away from the intermediate adhesive layer 12 and a second surface close to the intermediate adhesive layer 12, and the second glass plate 13 includes a third surface close to the intermediate adhesive layer 12 and a fourth surface facing away from the intermediate adhesive layer 12.

[0039] The laminated glass 1 has an image display area 10, which is used to receive and reflect projected light to form a display image. The projected light forms a reflected primary image and a reflected secondary image as the display image. At least within the range of the image display area, there is a wedge α between the first surface and the fourth surface.

[0040] The laminated glass 1 further includes an adjustment layer 14 located in the image display area 10. The adjustment layer 14 is disposed between the first glass plate 11 and the second glass plate 13. The adjustment layer 14 is used to convert S-polarized light into P-polarized light. When the proportion of S-polarized light in the projected light is ≥90% and the incident angle β of the projected light is >65°, the laminated glass 1 has a primary-to-secondary image brightness ratio RR12. The primary-to-secondary image brightness ratio RR12 is the brightness ratio of the reflected primary image to the reflected secondary image, and the primary-to-secondary image brightness ratio RR12 is ≥12.5.

[0041] The image display area 10 can display vehicle driving information, various patterns, or play videos, and can be used in various scenarios such as welcoming guests, creating an atmosphere, watching movies, and working. Optionally, it can be used to display driving parameters, including vehicle speed, engine speed, fuel consumption, tire pressure, warning information, and mileage. It can also be used to display weather temperature, entertainment information, and can be used for dynamic navigation, night vision, and real-view maps. Along the stacking direction of the laminated glass 1, the image display area 10 is at least partially covered by the adjustment layer 14. The image display area 10 has a primary image reflective layer that forms the primary image.

[0042] Optionally, the laminated glass 1 has at least one image display area 10. For example, the number of image display areas 10 can be one, or multiple, with the multiple image display areas 10 spaced apart. The number of image display areas 10 can be designed according to the actual product.

[0043] Optionally, the image display area 10 is located in the bottom region of the laminated glass 1, and / or in the top region of the laminated glass 1, and / or in the left region of the laminated glass 1, and / or in the right region of the laminated glass 1.

[0044] Optionally, the projected light includes S-polarized light. Specifically, the proportion of S-polarized light in the projected light is ≥90%, such as 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%. Preferably, the proportion of S-polarized light in the projected light is ≥95%. More preferably, the proportion of S-polarized light in the projected light is ≥97%.

[0045] The higher the proportion of S-polarized light in the projected light, the higher the proportion of P-polarized light converted by the adjustment layer 14, resulting in a dimmer reflected sub-image. Furthermore, the higher the proportion of S-polarized light in the projected light, the higher the reflectivity of the adjustment layer 14 to the reflected primary image, leading to higher brightness at eye level, lower energy consumption of the projection system, and a corresponding reduction in the brightness requirement of the projection light source.

[0046] Specifically, the first glass plate 11 serves as the outer glass plate of the laminated glass 1. The first glass plate 11 has a first surface and a second surface. The first surface is away from the intermediate adhesive layer 12 and is in contact with the external environment of the vehicle, while the second surface is close to the intermediate adhesive layer 12. The second glass plate 13 serves as the inner glass plate of the laminated glass 1. The second glass plate 13 has a third surface and a fourth surface. The third surface is close to the intermediate adhesive layer 12, while the fourth surface is away from the intermediate adhesive layer 12 and is in contact with the internal environment of the vehicle.

[0047] Furthermore, the primary image reflective layer is the fourth surface, or the primary image reflective layer is a reflective structure located on the fourth surface. The fourth surface is the surface of the second glass plate 13 that faces away from the first glass plate 11.

[0048] Optionally, the first glass plate 11 is transparent glass or colored glass, the thickness of the first glass plate 11 is 0.7mm to 4mm, and the visible light transmittance of the first glass plate 11 is greater than or equal to 70%. The second glass plate 13 is transparent glass or colored glass, the thickness of the second glass plate 13 is 0.7mm to 4mm, and the visible light transmittance of the second glass plate 13 is greater than or equal to 70%.

[0049] Optionally, the visible light transmittance of the laminated glass 1 is greater than or equal to 70%.

[0050] Preferably, the thickness of the second glass plate 13 is ≤2.1mm, specifically, it can be 2.1mm, 2mm, 1.8mm, 1.6mm, 1.4mm, 1.2mm, or 0.8mm, etc. More preferably, the thickness of the second glass plate 13 is ≤1.6mm, ≤1.4mm, ≤1.2mm, or ≤0.8mm.

[0051] This embodiment, by employing a thinner second glass plate 13, allows for a smaller deviation between the reflected secondary image and the reflected primary image, making it easier for them to overlap and resulting in a clearer display image, thus improving driving safety. Furthermore, it avoids the possibility of the laminated glass 1 being easily broken due to an excessively thin first glass plate 11 serving as the outer glass plate.

[0052] Preferably, at least within the image display area 10, the laminated glass 1 is provided with a coloring material, the visible light transmittance of the coloring material being ≥50%, ≥60%, or ≥70%.

[0053] Examples of visible light transmittance for coloring materials include 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, and 90%.

[0054] Specifically, the coloring material can be a first glass plate 11 that is colored by itself, or a second glass plate 13 that is colored by itself, or an intermediate adhesive layer 12 that is colored by itself, or an adjustment layer 14 that is colored by itself, or an additional coloring film layer.

[0055] More preferably, the first glass plate 11 and / or the second glass plate 13 are coloring layers.

[0056] For example, the first glass plate 11 and / or the second glass plate 13 may be light green glass or dark green glass.

[0057] More preferably, the intermediate adhesive layer 12 is a colored layer.

[0058] For example, the intermediate adhesive layer 12 uses a light gray intermediate film.

[0059] More preferably, the adjustment layer 14 is a coloring layer.

[0060] For example, adjustment layer 14 itself is a coloring layer.

[0061] This embodiment reduces the brightness of the ghosting of the reflected sub-image by providing a coloring material to the laminated glass 1, thereby making the displayed image clearer.

[0062] The intermediate adhesive layer 12 is a transparent or colored thermoplastic polymer film. Optionally, the thickness of the intermediate adhesive layer 12 is 0.38 mm to 2.28 mm, specifically, 0.38 mm, 0.76 mm, 1.14 mm, 1.52 mm, 1.9 mm, or 2.28 mm. Preferably, the thickness of the intermediate adhesive layer 12 is 0.76 mm. Optionally, the visible light transmittance of the intermediate adhesive layer 12 is greater than or equal to 85%, specifically, 85%, 90%, or 95%. Optionally, the haze of the intermediate adhesive layer 12 is less than or equal to 1%, specifically, 1%, 0.8%, 0.6%, or 0.4%. Optionally, the material of the thermoplastic polymer film can be selected from at least one of polyvinyl butyral (PVB), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), and ionic polymer (SGP). Colored thermoplastic polymer films can be gray, green, or blue.

[0063] For example, the intermediate adhesive layer 12 can be a single-layer or multi-layer structure. Examples of multi-layer structures include double-layer, triple-layer, quadruple-layer, and five-layer structures. The intermediate adhesive layer 12 can also have other functions, such as providing at least one colored area as a shaded zone to reduce sunlight interference with the human eye, adding infrared absorbers to provide sun protection or heat insulation, adding ultraviolet absorbers to provide ultraviolet protection, or having at least one layer of the multi-layer structure with a higher plasticizer content to provide sound insulation.

[0064] In one embodiment, the intermediate adhesive layer 12 includes a first adhesive layer 121 and a second adhesive layer 122, and the first glass plate 11, the first adhesive layer 121, the adjustment layer 14, the second adhesive layer 122, and the second glass plate 13 are stacked sequentially.

[0065] Furthermore, the sum of the thicknesses of the first adhesive layer 121 and the second adhesive layer 122 is 0.38 mm to 2.28 mm, specifically, for example, 0.38 mm, 0.76 mm, 1.14 mm, 1.52 mm, 1.9 mm, or 2.28 mm. Preferably, the sum of the thicknesses of the first adhesive layer 121 and the second adhesive layer 122 is 0.76 mm.

[0066] Furthermore, the thickness ratio K of the first adhesive layer 121 and the second adhesive layer 122 satisfies: K = 1 ± 0.5, or = 1 ± 0.2, or = 1 ± 0.1.

[0067] Optionally, the first adhesive layer 121 and the second adhesive layer 122 are made of the same material. For example, the first adhesive layer 121 / adjusting layer 14 / second adhesive layer 122 is 0.38mm PVB / adjusting layer 14 / 0.38mm PVB. Another example is that the first adhesive layer 121 / adjusting layer 14 / second adhesive layer 122 is 0.76mm PVB / adjusting layer 14 / 0.38mm PVB. Yet another example is that the first adhesive layer 121 / adjusting layer 14 / second adhesive layer 122 is 0.38mm PVB / adjusting layer 14 / 0.76mm PVB.

[0068] The regulating layer 14 is disposed between the first adhesive layer 121 and the second adhesive layer 122, which can improve the impact resistance of the laminated glass 1 and enhance the durability of the regulating layer 14 against ultraviolet rays.

[0069] Optionally, the thickness ratio K of the first adhesive layer 121 and the second adhesive layer 122 is 1±0.5, that is, the first adhesive layer 121 and the second adhesive layer 122 are of equal or nearly equal thickness and made of the same material. This can avoid uneven deformation of the adjustment layer 14 in the high temperature and high pressure environment of the glass lamination process, which would lead to orange peel texture in the image and improve the yield of the laminated glass 1.

[0070] Specifically, the projection device 21 is located on the side of the second glass plate 13 facing away from the intermediate adhesive layer 12. The projection light emitted by the projection device 21 is reflected once in the image display area 10 on the fourth surface of the second glass plate 13 to form reflected light RL1, which enters the human eye and forms a reflected primary image. At the same time, the projection light enters the interior of the laminated glass 1, is reflected on the first surface of the first glass plate 11 to form reflected light RL2, and then enters the human eye to form a reflected secondary image.

[0071] The laminated glass 1 has a wedge shape, which is formed between the outer surface of the first glass plate 11 and the outer surface of the second glass plate 13, as shown in the figure. Figure 2 As shown in α, the wedge is used to adjust the secondary image, ensuring that the displacement difference between the secondary image and the primary image is within a preset range. This allows the secondary image to overlap or nearly overlap with the primary image, reducing the blurriness and dizziness experienced by the human eye and making the displayed image clearer.

[0072] The wedge α is used to ensure that the displacement difference between the secondary reflective image and the primary reflective image is within a preset range, wherein the preset range is ≤4.5arcmin.

[0073] Specific examples of the preset range include 4.5 arcmin, 4 arcmin, 3.5 arcmin, 3 arcmin, 2.5 arcmin, 2 arcmin, 1.5 arcmin, 1 arcmin, 0.5 arcmin, or 0. Preferably, the preset range is ≤3.5 arcmin. More preferably, the preset range is ≤2.5 arcmin.

[0074] In one embodiment, the wedge α is provided by at least one of the first glass plate 11, the intermediate adhesive layer 12, the adjustment layer 14, and the second glass plate 13.

[0075] For example, wedge α may be provided by one of the following: first glass plate 11, intermediate adhesive layer 12, adjusting layer 14, or second glass plate 13. Alternatively, wedge α may be provided by a combination of first glass plate 11 and intermediate adhesive layer 12. Yet another example is that wedge α may be provided by a combination of first glass plate 11 and second glass plate 13. Still another example is that wedge α may be provided by a combination of intermediate adhesive layer 12 and second glass plate 13. And yet another example is that wedge α may be provided by a combination of all three: first glass plate 11, intermediate adhesive layer 12, and second glass plate 13.

[0076] Optionally, the wedge α can be a fixed wedge or a variable wedge that changes linearly or nonlinearly.

[0077] Further optionally, the wedge shape of the first glass plate 11, and / or the intermediate adhesive layer 12, and / or the adjusting layer 14, and / or the second glass plate 13 varies linearly, or the wedge shape of the first glass plate 11, and / or the intermediate adhesive layer 12, and / or the adjusting layer 14, and / or the second glass plate 13 varies monotonically and non-linearly.

[0078] Optionally, the thickness of the laminated glass 1 gradually increases along its arrangement direction from the bottom edge to the top edge. In other words, the laminated glass 1 is thinner at the bottom and thicker at the top.

[0079] In another embodiment, the wedge angle of the wedge α is ≤0.72mrad.

[0080] The wedge angle of wedge α can be specifically exemplified as 0.72 mrad, 0.7 mrad, 0.65 mrad, 0.6 mrad, 0.55 mrad, 0.5 mrad, 0.45 mrad, 0.4 mrad, 0.35 mrad, 0.3 mrad, 0.25 mrad, or 0.2 mrad, etc. Preferably, the wedge angle of wedge α is ≤0.50 mrad, ≤0.40 mrad, or ≤0.30 mrad.

[0081] The wedge angle of the wedge α can be designed according to the HUD optical path and adjusted according to product requirements.

[0082] And / or, the rate of change of the wedge angle of the wedge α is ≤0.3mrad / 100mm.

[0083] Compared to related technologies that prepare glass plates with fixed wedge angles or variable wedge shapes, this application preferably uses a gradually decreasing wedge angle for the wedge α. This gradually decreasing wedge angle is beneficial for glass plate production, reduces manufacturing difficulty, and improves product yield.

[0084] The rate of change of the wedge angle of wedge α can be exemplified by, for example, 0.3 mrad / 100 mm, or 0.275 mrad / 100 mm, or 0.25 mrad / 100 mm, or 0.225 mrad / 100 mm, or 0.2 mrad / 100 mm, or 0.175 mrad / 100 mm, or 0.15 mrad / 100 mm, or 0.125 mrad / 100 mm, or 0.1 mrad / 100 mm, etc. Preferably, the rate of change of the wedge angle of wedge α is ≤0.2 mrad / 100 mm, or ≤0.1 mrad / 100 mm.

[0085] The wedge angle variation rate of the wedge α can be designed according to the HUD optical path and adjusted according to product requirements.

[0086] In another embodiment, the first glass plate 11 and / or the second glass plate 13 have a wedge angle, and the wedge angle of the first glass plate 11 and / or the second glass plate 13 has a first local wedge angle fluctuation standard deviation σ1 within the image display area 10, the first local wedge angle fluctuation standard deviation σ1 satisfying the following condition: 3σ1≤0.08mrad / 10mm.

[0087] The method for measuring the standard deviation of local wedge angle fluctuation is as follows: along the direction of the wedge angle, the measurement points are spaced 10 mm apart, and the standard deviation of the deviation between the wedge angle of multiple measurement points and the corresponding expected design wedge angle is measured.

[0088] The first local wedge angle fluctuation standard deviation σ1 can be exemplified as follows: 3σ1≤0.08mrad / 10mm, or 3σ1≤0.07mrad / 10mm, or 3σ1≤0.06mrad / 10mm, or 3σ1≤0.05mrad / 10mm, or 3σ1≤0.04mrad / 10mm, or 3σ1≤0.03mrad / 10mm, or 3σ1≤0.02mrad / 10mm, or 3σ1≤0.01mrad / 10mm, etc.

[0089] Preferably, the standard deviation σ1 of the first local wedge angle fluctuation satisfies the following condition: 3σ1≤0.05mrad / 10mm. More preferably, the standard deviation σ1 of the first local wedge angle fluctuation satisfies the following condition: 3σ1≤0.03mrad / 10mm.

[0090] Therefore, this embodiment limits the standard deviation σ1 of the first local wedge angle fluctuation to select a glass plate with smaller local wedge angle fluctuation. The smaller the local wedge angle fluctuation, the better the superposition stability of the ghost image and the main image.

[0091] And / or, the intermediate adhesive layer 12 has a wedge angle, the wedge angle of the intermediate adhesive layer 12 having a second local wedge angle fluctuation standard deviation σ2 within the image display area 10, the second local wedge angle fluctuation standard deviation σ2 satisfying the following condition: 3σ2≤0.15mrad / 10mm.

[0092] The second local wedge angle fluctuation standard deviation σ2 can be exemplified by 3σ2≤0.15mrad / 10mm, or 3σ2≤0.14mrad / 10mm, or 3σ2≤0.13mrad / 10mm, or 3σ2≤0.12mrad / 10mm, or 3σ2≤0.11mrad / 10mm, or 3σ2≤0.1mrad / 10mm, or 3σ2≤0.09mrad / 10mm, or 3σ2≤0.08mrad / 10mm, or 3σ2≤0.07mrad / 10mm, or 3σ2≤0.06mrad / 10mm, or 3σ2≤0.05mrad / 10mm, etc.

[0093] Preferably, the standard deviation σ2 of the second local wedge angle fluctuation satisfies the following condition: 3σ2 ≤ 0.12 mrad / 10 mm. More preferably, the standard deviation σ2 of the second local wedge angle fluctuation satisfies the following condition: 3σ2 ≤ 0.1 mrad / 10 mm.

[0094] Therefore, this embodiment selects an intermediate adhesive layer 12 with smaller local wedge angle fluctuations by limiting the second local wedge angle fluctuation standard deviation σ2. The smaller the local wedge angle fluctuation, the better the superposition stability of the ghost image and the main image.

[0095] In yet another embodiment, the first glass plate 11 and / or the second glass plate 13, which are wedge-shaped, have a spray direction, which is either vertical or horizontal. Preferably, the spray direction is vertical.

[0096] The direction of the molten glass runner refers to the direction in which the molten glass moves across the surface of the molten tin during the float glass production process. This embodiment, by limiting the molten glass runner direction to vertical or horizontal, can reduce driver visual distortion and fatigue, lessen the blurriness and dizziness experienced when viewing images, thereby improving driver comfort and safety.

[0097] The adjustment layer 14 is used to convert S-polarized light into P-polarized light to reduce the brightness of the ghosting of the reflected sub-image and make the displayed image clearer.

[0098] The projected light can pass through the adjustment layer 14. Specifically, the adjustment layer 14 has a conversion rate of ≥90% for the S-polarized light.

[0099] The conversion efficiency of the adjustment layer 14 for S-polarized light can be exemplified by, for example, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%. Preferably, the conversion efficiency of the adjustment layer 14 for S-polarized light is ≥95%. More preferably, the conversion efficiency of the adjustment layer 14 for S-polarized light is ≥99%.

[0100] The higher the conversion rate of the adjustment layer 14 to S-polarized light, the dimmer the reflected sub-image, making the displayed image clearer.

[0101] And / or, the thickness of the adjustment layer 14 is 2μm~200μm.

[0102] The thickness of the adjustment layer 14 can be specifically exemplified as 2μm, 5μm, 10μm, 25μm, 50μm, 75μm, 100μm, 125μm, 150μm, 175μm, or 200μm, etc.

[0103] And / or, the internal reflectivity of the adjustment layer 14 in the laminated glass 1 is ≤2%.

[0104] The internal reflectivity of the adjusting layer 14 in the laminated glass 1 can be specifically exemplified as 2%, 1.8%, 1.6%, 1.4%, 1.2%, 1%, 0.8%, 0.6%, 0.5%, 0.4%, or 0.2%, etc.

[0105] By limiting the reflectivity of the adjustment layer 14 to be low within the laminated glass 1, so that the adjustment layer 14 and the intermediate adhesive layer 12 have similar refractive indices, the ghosting caused by the adjustment layer 14 itself can be reduced, making the ghosting reflected by the adjustment layer 14 sufficiently dim, thereby reducing or even avoiding the impact on the clarity of the displayed image.

[0106] In one embodiment, the adjustment layer 14 is selected from a half-wave plate film.

[0107] When normally incident light passes through, the phase difference between the ordinary ray (o ray) and the extraordinary ray (e ray) is equal to π or an odd multiple thereof. Such a wafer is called a half-wave plate, or simply a half-wave plate or λ / 2 wave plate.

[0108] Furthermore, the half-wave plate film is selected from at least one of polyimide-based thin film half-wave plates, liquid crystal polymer thin film half-wave plates, indium tin oxide thin film half-wave plates, quartz-based flexible thin film half-wave plates, nanocomposite thin film half-wave plates, graphene-oxide composite thin film half-wave plates, and ultrathin dielectric metasurface half-wave plates.

[0109] Alternatively, the half-wave plate film may consist of N λ / M waveplates; where N×λ / M=λ / 2.

[0110] For example, when N=2 and M=4, a half-wave plate film is formed by combining two λ / 4 wave plates.

[0111] Alternatively, the half-wave plate film may contain a liquid crystal structure capable of polarization rotation.

[0112] For example, controlling the polarization rotation of the liquid crystal structure by 90° to form a half-wave plate film can also be called a 90° deflection conversion film or a generalized half-wave plate film.

[0113] Specifically, when the projected light contains S-polarized light, the proportion of S-polarized light in the projected light is ≥90%, and the incident angle β of the projected light is >65°, the brightness ratio RR12 of the primary and secondary images of the laminated glass 1 is ≥12.5.

[0114] The primary-secondary image brightness ratio RR12 can be exemplified by values ​​such as 12.5, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60. Preferably, the primary-secondary image brightness ratio RR12 ≥ 15; more preferably, the primary-secondary image brightness ratio RR12 ≥ 20; and even more preferably, the primary-secondary image brightness ratio RR12 ≥ 25.

[0115] The greater the brightness ratio (RR12) between the primary and secondary images, the dimmer the reflected secondary image and the clearer the displayed image. Furthermore, the greater the brightness of the reflected primary image, the brighter the primary image, resulting in lower energy consumption for the projection system and a corresponding reduction in the brightness requirement of the projection light source.

[0116] The incident angle β of the projected light can be exemplified by 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, or 75°, etc. The incident angle β of the projected light is based on the principal ray of the central eyepiece.

[0117] In summary, the laminated glass 1 provided in this embodiment not only minimizes the ghosting separation between the reflected primary image and the reflected secondary image by setting a wedge shape, but also converts S-polarized light into P-polarized light by setting an adjustment layer 14. Combined with the projection light with a high proportion of S-polarized light and a high incident angle, the reflected secondary image is made dim. The laminated glass 1 has a high primary-to-secondary image brightness ratio RR12, thereby achieving synergy with the head-up display system. By utilizing the visual masking effect in visual perception, the user can observe a clear display image, improving driving safety.

[0118] On the one hand, this embodiment sets a wedge α to reduce ghosting. On the other hand, it uses an adjustment layer 14 to weaken the ghosting brightness of the reflected sub-image. The two are synergistic and need to be considered from a holistic perspective: combining the advantages and disadvantages of the two ghosting elimination techniques, the visual masking effect, the relationship between ghosting separation, ghosting dimness and human eye recognition, the relationship between HUD optical path specifications and ghosting, the relationship between the incident angle and the brightness of each reflected image, the actual manufacturing tolerance of the sheet and the problems it causes, the production process of the wedge original sheet, product cost and product experience, and the interrelationships between these aspects, considering the overall HUD system, thus obtaining the technical solution provided by this embodiment.

[0119] In another embodiment, the image display area 10 is also used to receive and transmit external light, which forms a transmissive primary image TL1 and a transmissive secondary image TL2. The laminated glass 1 has a primary-to-secondary image transmittance ratio TT12, which is the ratio of the visible light transmittance of the primary image TL1 to the secondary image TL2, and the primary-to-secondary image transmittance ratio TT12 ≥ 40.

[0120] The primary image TL1 is formed by the transmission of external light through the laminated glass 1, and the secondary image TL2 is formed by the refraction and reflection of external light through the first glass plate 11 and the second glass plate 13. Compared to the primary image TL1, the external light undergoes an additional reflection and refraction before entering the human eye, and the observed transmission image is called the secondary image TL2.

[0121] The transmittance ratio TT12 of the primary and secondary images can be exemplified as 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 100, etc. Preferably, the transmittance ratio TT12 of the primary and secondary images is ≥50. More preferably, the transmittance ratio TT12 of the primary and secondary images is ≥60.

[0122] The larger the transmittance ratio TT12 between the main and secondary images, the dimmer the secondary image TL2 will be, resulting in clearer external information and further improving driving safety.

[0123] Please refer to Figure 3In another embodiment, the displayed image can be observed at the eye box, which includes an upper eye box, a middle eye box, and a lower eye box corresponding to each virtual image plane.

[0124] The display image corresponding to the upper eyelid box is tilted away from the eyelid box.

[0125] And / or, the display image corresponding to the eye box is tilted away from the eye box.

[0126] And / or, the display image corresponding to the lower eyelid box is tilted away from the eyelid box.

[0127] In related technologies, in the design of HUD optical paths, the virtual image target is usually positioned approximately vertically on the ground or perpendicular to the line of sight. However, at high incident angles, the actual virtual image often tends to tilt backward, meaning it tilts in the opposite direction, with the upper part of the virtual image tilting closer to the driver. This results in a significant uneven distribution of ghosting, typically with larger values ​​at the top and smaller values ​​at the bottom, creating a large difference between the upper and lower parts, making it difficult to reduce ghosting. Specifically, the ghosting value is set to positive when the ghosting is above the main image and negative when it is below the main image.

[0128] The displayed image is tilted away from the eye box, which can also be understood as the virtual image tilting forward and away from the driver.

[0129] This embodiment limits the display images corresponding to the upper, middle, and lower eye boxes to tilt away from the eye boxes. In other words, it limits the display images to tilt forward, making the distribution of ghost images more uniform. Combined with the wedge α defined in this embodiment, the ghost images are easier to overlap, the ghost images are smaller, and the image is clearer.

[0130] Furthermore, the display image corresponding to the middle eye box is tilted away from the eye box, and the tilt angle γ of the display image corresponding to the middle eye box is ≥45°.

[0131] The tilt angle γ of the displayed image corresponding to the middle eye box can be specifically exemplified as 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°, etc. Preferably, the tilt angle γ ≥ 75°. More preferably, the tilt angle γ ≥ 85°.

[0132] like Figure 3 As shown, the tilt angle γ of the display image corresponding to the middle eye box is a plane that passes through the main line of sight of the HUD and provides a plane along the Z-axis of the vehicle body coordinate system. It intersects with the virtual image perceived by the human eye to form an intersection line. The line connecting the two endpoints of this intersection line forms an angle γ with the Z-axis direction. The upper endpoint is further forward, which is a positive angle.

[0133] Optionally, the virtual image distance VID of the displayed image is ≥2m, specifically for example, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, or 5m, etc.

[0134] Preferably, the virtual image distance VID of the displayed image is ≥3m, and more preferably, the virtual image distance VID of the displayed image is ≥4.5m.

[0135] In yet another embodiment, the vertical field of view (VFOV) of the image display area 10 is ≤5°.

[0136] The vertical field of view (VFOV) of the image display area 10 refers to the maximum angular range that the projection system can present virtual images in the vertical direction.

[0137] The vertical field of view (VFOV) can be specifically exemplified as 5°, 4°, 3°, 2°, or 1°, etc. Preferably, the VFOV of the image display area 10 is ≤4°. More preferably, the VFOV of the image display area 10 is ≤3°.

[0138] This embodiment optimizes the vertical ghosting at various positions of the virtual image by setting a wedge α, and reduces the vertical field of view (VFOV) to reduce the maximum amount of ghosting, thereby further improving the clarity of the displayed image.

[0139] In yet another embodiment, the square root Gaussian curvature SRG of the first glass plate 11 and / or the second glass plate 13 is ≤0.00025mm. -1 .

[0140] For example, the square root Gaussian curvature (SRG) can be 0.00025 mm. -1 or 0.00023mm -1 or 0.0002mm -1 or 0.00018mm -1 or 0.00015mm -1 or 0.00012mm -1 or 0.0001mm -1 or 0.00005mm -1 Etc. Preferably, the square root Gaussian curvature SRG of the first glass plate 11 and / or the second glass plate 13 is ≤0.00018mm. -1 More preferably, the square root Gaussian curvature SRG of the first glass plate 11 and / or the second glass plate 13 is ≤0.00012 mm. -1 .

[0141] The adjustment layer 14 and the intermediate adhesive layer 12 are flat films. The first glass plate 11 and the second glass plate 13 have free-form surfaces that are curved in the longitudinal and transverse directions. When the adjustment layer 14 is sandwiched between the first glass plate 11 and the second glass plate 13, the adjustment layer 14 will be slightly deformed to varying degrees, which will lead to distortion of the optical reflection image.

[0142] Since the sub-image of the adjustment layer is not completely invisible, it is typically a dim, irregular superimposed image resembling water ripples. To suppress this water ripple distortion, the glass surfaces of the first glass plate 11 and the second glass plate 13 should be as flat as possible. Therefore, this embodiment limits the square root Gaussian curvature (SRG) to minimize the curvature of the glass surfaces of the first glass plate 11 and / or the second glass plate 13, thereby suppressing the water ripple distortion of the sub-image of the adjustment layer and further improving the clarity of the displayed image.

[0143] Preferably, the incident angle β of the projected light satisfies the following condition: 65°<β≤75°.

[0144] Adjustment layer 14 converts S-polarized light into P-polarized light, with the incident angle getting closer to the Brewster angle θ of the glass. B (≈57°) The less P-polarized light incident on the first surface will be reflected back to the human eye, the dimmer the reflected sub-image will be, and the clearer the image will be. In related technologies, the range of 50°≤β≤65° is generally considered a suitable range for conventional glass to solve the ghosting problem using adjustment layer 14. If this technology is used within the range of 50°≤β≤65°, the cost will increase significantly, and the cost-benefit ratio will decrease significantly.

[0145] If the angle of incidence is greater than 75°, the angle of incidence will be too large, which will lead to a decrease in the brightness ratio of the primary and secondary images RR12, a decrease in the transmittance ratio of the primary and secondary images TT12, a decrease in visibility outside the vehicle, and a greater ghosting of the reflected secondary images. Even with wedge α adjustment, it will be difficult to overlap, and the overall driving experience will be significantly reduced.

[0146] The incident angle β of the projected light is based on the principal ray of the central eye box.

[0147] This application also provides a projection system, which includes a projection device and a laminated glass as described above. The projection device is disposed on the side of the second glass plate away from the intermediate adhesive layer. The projection device is used to generate projection light, which includes S-polarized light. The proportion of S-polarized light in the projection light is ≥90%. The image display area is used to receive and reflect the projection light to form a display image.

[0148] Optionally, the wavelength of the projected light includes 380nm to 780nm.

[0149] This application also provides a vehicle, the vehicle including a body and laminated glass as described above, the laminated glass being disposed on the body.

[0150] The projection device of the projection system can be installed inside the vehicle body, while the laminated glass is installed at the opening in the vehicle body.

[0151] When laminated glass is installed in a vehicle, it is preferably used as the windshield. However, it is not limited to this; laminated glass can also be used as the rear windshield or side window, thus providing more display applications for the vehicle. In addition to vehicles, laminated glass can also be used in transportation vehicles such as airplanes, trains, and rail transit.

[0152] The projection system and vehicle provided in this application utilize the laminated glass provided in this application. The laminated glass not only has a wedge shape to minimize the ghosting separation between the reflected primary image and the reflected secondary image, but also has an adjustment layer to convert S-polarized light into P-polarized light. Combined with the projection light with a high proportion of S-polarized light and a high incident angle, the reflected secondary image becomes dim. The laminated glass has a high primary-to-secondary image brightness ratio RR12, thereby achieving synergy with the head-up display system. By utilizing the visual masking effect in visual perception, the user can observe a clear display image, improving driving safety.

[0153] The vertical ghosting between the reflected secondary image and the reflected primary image, along with the primary-secondary image brightness ratio (RR12), both contribute to the image's clarity. Better RR12 results in a clearer image perceived by the human eye and a higher coverage ratio. A higher RR12 ratio allows for a greater amount of ghosting at the same resolution.

[0154] For example, when the TL0 of the laminated glass is 70% and the conversion rate of the adjustment layer to S-polarized light is 95%, the brightness ratio of the primary and secondary images (RR12) is 31.2. At this time, the ghosting amount of 4.5 arcmin can meet the needs of most drivers and scenarios. If the brightness ratio of the primary and secondary images (RR12) is too low, then a smaller ghosting separation is required.

[0155] To make the objectives and advantages of this application clearer, the effects of the laminated glass of this application will be further explained in detail below with reference to specific embodiments.

[0156] Verification 1: This verification uses simulation calculations. Please refer to the simulation conditions. Figure 4 In this embodiment, the laminated glass consists of 2.1mm ordinary glass + 0.38mm wedge-shaped PVB + 0.1mm transparent half-wave sheet + 0.38mm PVB + 2.1mm ordinary glass.

[0157] The wedge-shaped α example is on the intermediate adhesive layer, but it can obviously be on any one or more sheet layers. The projection light source is S-polarized light, and the vertical visible light transmittance TL0 of the laminated glass can be adjusted as needed, with the variable being the angle of incidence (AOI), as detailed in Table 1. The simulation data results are summarized below. Figure 4 As shown.

[0158] Table 1: Simulation Condition Parameters for Laminated Glass in Examples A1-A3

[0159] Observation Table 1 and Figure 4 It can be seen that as the incident angle AOI moves further away from the Brewster angle θ B When the incident angle AOI increases from 65° to 80°, the primary-to-secondary image reflectance ratio RR12 first decreases and then increases, resulting in a deterioration in performance. The primary-to-secondary image transmittance ratio TT12 decreases significantly. Starting from 72.7°, 74.1°, and 75.7°, the laminated glass with different transmittance gradually fails to meet the requirement of a 40:1 ratio of primary-to-secondary image transmittance ratio TT12. Overall, both the primary-to-secondary image reflectance ratio RR12 and the primary-to-secondary image transmittance ratio TT12 of the laminated glass deteriorate.

[0160] As the transmittance of laminated glass decreases, both the primary and secondary image reflectance ratio RR12 and the primary and secondary image transmittance ratio TT12 increase. Obviously, reducing the vertical visible light transmittance TL0 helps improve the indicators; however, this will reduce visibility outside the vehicle, and therefore its range is also limited.

[0161] Therefore, under multiple objective requirements, including primary and secondary image reflectance ratio RR12≥12.5:1, vertical visible light transmittance TL0≥70%, and primary and secondary image transmittance ratio TT12≥40:1, the effect achieved by the laminated glass provided in this application cannot be easily met by ordinary laminated glass in related technologies. It is necessary to take into account both transmittance and incident angle.

[0162] Furthermore, based on Table 1, different conversion rates ψ were used for simulation, with the transmittance TL0 as the variable. The specific changes are shown in Table 2 below. The simulation data results are summarized below. Figure 5 As shown. At this incident angle AOI, the transmittance ratio TT12 of both the primary and secondary images is >65:1, therefore the transmittance ratio TT12 of the primary and secondary images is not within the range of [missing information]. Figure 5 As shown in the diagram.

[0163] Table 2: Simulation Condition Parameters for Laminated Glass in Examples B1-B5

[0164] Observation Table 2 and Figure 5 It can be seen that as the visible light transmittance TL0 increases, the primary and secondary image reflectance ratio RR12 decreases monotonically, and the effect deteriorates.

[0165] As the polarization conversion rate ψ increases, the primary-to-secondary image reflectance ratio RR12 increases. For low visible light transmittance TL0, the increase in primary-to-secondary image reflectance ratio RR12 is more significant. For high visible light transmittance TL0, the primary-to-secondary image reflectance ratio RR12 is mostly below 20:1. Therefore, laminated glass preferably has a visible light transmittance TL0 ≤ 80%, and more preferably, a visible light transmittance TL0 ≤ 75%. In summary, under multiple objective requirements, including primary and secondary image reflectance ratio RR12≥12.5:1, vertical visible light transmittance TL0≥70%, and primary and secondary image transmittance ratio TT12≥40:1, the laminated glass provided in this application achieves effects that cannot be easily met by ordinary laminated glass in related technologies. It is necessary to take into account transmittance TL0, incident angle AOI, and polarization conversion rate ψ.

[0166] Verification 2: The adjustment layer is sealed inside the laminated glass through high-temperature forming and lamination processes. The optical path parameters of the head-up display system are as follows: the eye box is divided into an upper eye box, a middle eye box, and a lower eye box. Each eye box has a size of 130×50mm. The vertical movement distance of each eye box is 50mm. The field of view (HFOV) is 10°, the visual field (VFOV) is 5°, the virtual image distance is 8500mm, the incident angle (AOI) of the principal optical axis of the middle eye box at the inner surface of the glass is 67.6°, and the downward viewing angle is 2.3° (downward is a positive value).

[0167] Comparative Example 1: 2.1mm glass plate / 0.76mm wedge-shaped PVB / 2.1mm glass plate, the visible light transmittance (TL0) of the laminated glass is 80%, and the square root Gaussian curvature (SRG) of the image display area is 0.000147mm. -1 .

[0168] Comparative Example 2: 2.1mm glass plate / 0.38mm PVB / 0.1mm transparent half-wave plate / 0.38mm PVB / 2.1mm glass plate, the visible light transmittance (TL0) of the laminated glass is 79.5%, and the square root Gaussian curvature (SRG) of the image display area is 0.000147mm. -1 .

[0169] Example 1: 2.1mm glass plate / 0.38mm wedge-shaped PVB / 0.1mm transparent half-wave plate / 0.38mm PVB / 2.1mm glass plate, the visible light transmittance (TL0) of the laminated glass is 79.5%, and the square root Gaussian curvature (SRG) of the image display area is 0.000147mm. -1 .

[0170] Example 2: A laminated glass consisting of a 2.1mm glass plate, a 0.38mm wedge-shaped PVB sheet, a 0.1mm transparent half-wave plate, and a 0.38mm PVB sheet. The visible light transmittance (TL0) of the laminated glass is 71.1%, and the square root Gaussian curvature (SRG) of the image display area is 0.000147mm. -1 .

[0171] Example 3: 2.1mm glass plate / 0.38mm wedge-shaped PVB / 0.1mm transparent half-wave plate / 0.38mm PVB / 1.8mm glass plate, the visible light transmittance (TL0) of the laminated glass is 71.1%, and the square root Gaussian curvature (SRG) of the image display area is 0.000147mm. -1 .

[0172] Table 3: Data parameters of laminated glass in Comparative Examples 1-2 and Examples 1-3

[0173] Table 4: Virtual Image Attitudes of Laminated Glass in Comparative Examples 1-2 and Examples 1-3

[0174] Table 5: Visual Effects of Laminated Glass in Comparative Examples 1-2 and Examples 1-3

[0175] according to Figures 6-8 As shown in Table 3, the vehicle model provided in this embodiment has a relatively small mounting angle of 23.9° and a relatively large incident angle AOI of 67.6°. As the wedge angle increases, the amount of ghosting at each eye position is relatively large.

[0176] In Comparative Example 1, the optimal wedge angle is found at 0.175 mrad, which effectively balances ghosting at different eye positions. As the wedge angle deviates from the theoretically optimal wedge angle, the ghosting at the upper or lower eye positions increases significantly. Overall, when the laminated glass is at the optimal wedge angle, the corresponding maximum vertical ghosting is 1.8 arcmin. Obviously, considering manufacturing tolerances, the expected maximum vertical ghosting for the entire eye box is 4.1 arcmin, which is far beyond what the human eye can accept. This indicates that the ghosting in such a large incident angle HUD optical path is excessive in both theoretical design and manufacturing.

[0177] In Example 3, the optimal wedge angle is found at 0.165 mrad, which effectively balances ghosting at different eye positions. As the wedge angle deviates from the theoretically optimal angle, ghosting at the upper or lower eye positions increases significantly. Overall, when the laminated glass is at the optimal wedge angle, the maximum vertical ghosting is 1.5 arcmin. Considering manufacturing tolerances, the expected maximum vertical ghosting for the entire eye box is 3.5 arcmin, with 3.0 arcmin being achieved in the middle eye box. From the perspective of ghosting offset alone, Example 3 shows a significant reduction in ghosting offset compared to Comparative Example 1. For example, with a maximum ghosting baseline of 3.0 arcmin, the difference in Comparative Example 1 is 1.1 arcmin, while the difference in Example 3 is 0.5 arcmin.

[0178] Combination Figures 6-8 Tables 3-5 show that in Comparative Example 2, when only a half-wave plate is used, the theoretical wedge angle is 0 mrad, the maximum vertical ghosting is 4.2 arcmin, and the expected maximum vertical ghosting for the entire eyebox is 5.85 arcmin; since the incident angle AOI is 67.6° far from the Brewster angle θ B (≈57°), the primary and secondary image reflectance ratio RR12 is 18.5, the secondary image still exists, and the secondary image with excessive deviation will appear in high contrast environments such as night, tunnels, underground parking garages and other specific scenes, making the overall image blurry and unacceptable.

[0179] In Example 1, although the brightness ratio RR12 of the primary and secondary images is 18.5, the reflected secondary image does not completely disappear. However, the reflected secondary image and the reflected primary image visually overlap in most areas of the image. The reflected secondary image is relatively dim. Due to the visual masking effect, the reflected secondary image in the vicinity is difficult to detect. Even in a high-contrast environment, it is generally acceptable.

[0180] In Example 2, compared to Example 1, the visible light transmittance TL0 was further reduced. The visible light transmittance TL0 of Example 1 was 79.5%, while that of Example 2 was 71.1%. The thickness of the second glass plate was also reduced from 2.1 mm to 1.8 mm. As a result, the reflected sub-image became dimmer, the brightness ratio of the primary and secondary images RR12 increased to 24.5, the ghosting was slightly reduced, and the acceptance of the reflected sub-image increased in a wider field of view and in more scenarios.

[0181] In Example 3, compared to Example 2, the HUD virtual image pose was further optimized. All three virtual images are tilted forward with tilt angles of 87°, 80°, and 70°, respectively. As a result, the ghosting is further reduced, with the ghosting amount decreasing from 3.9 arcmin to 3.5 arcmin. The reflected sub-image is closer to the bright reflected main image, resulting in a more obvious visual masking effect. The acceptance of the reflected sub-image is further improved in a wider field of view and in more scenarios, thus reducing the cost of the product while maintaining the same quality.

[0182] Furthermore, since half-wave plates typically have some degree of wrinkles during glass production, the secondary image reflected by the adjustment layer will exhibit dim water ripples and flocculent irregular distortions. The smoother the glass, the better the image. In this embodiment, the square root Gaussian curvature (SRG) of the image display area is 0.000147 mm. -1 The distortion of the secondary image reflected by the adjustment layer is relatively mild and acceptable.

[0183] Unless otherwise stated or in case of conflict, the terms or phrases used in this application shall have the following meanings: In this application, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0184] In this application, "one or more" refers to any one, any two, or any two or more of the listed items. "Several" refers to any two or more.

[0185] In this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0186] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0187] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0188] The above description represents some embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A laminated glass, characterized in that, The laminated glass comprises a first glass plate, an intermediate adhesive layer, and a second glass plate stacked sequentially. The first glass plate includes a first surface facing away from the intermediate adhesive layer and a second surface close to the intermediate adhesive layer; the second glass plate includes a third surface close to the intermediate adhesive layer and a fourth surface facing away from the intermediate adhesive layer. The laminated glass has an image display area for receiving and reflecting projected light to form a display image. The projected light forms a reflected primary image and a reflected secondary image as the display image. At least within the area of ​​the image display area, a wedge α is formed between the first surface and the fourth surface. The laminated glass also includes an adjustment layer located in the image display area. The adjustment layer is disposed between the first glass plate and the second glass plate. The adjustment layer is used to convert S-polarized light into P-polarized light. When the proportion of S-polarized light in the projected light is ≥90% and the incident angle β of the projected light is >65°, the laminated glass has a primary-to-secondary image brightness ratio RR12. The primary-to-secondary image brightness ratio RR12 is the brightness ratio of the reflected primary image to the reflected secondary image, and the primary-to-secondary image brightness ratio RR12 is ≥12.

5.

2. The laminated glass as described in claim 1, characterized in that, The wedge α is used to keep the displacement difference between the secondary reflective image and the primary reflective image within a preset range, wherein the preset range is ≤4.5arcmin.

3. The laminated glass as described in claim 1, characterized in that, The wedge angle of the wedge α is ≤0.72mrad; And / or, the rate of change of the wedge angle of the wedge α is ≤0.3mrad / 100mm.

4. The laminated glass as described in claim 1, characterized in that, The first glass plate and / or the second glass plate have a wedge angle, and the wedge angle of the first glass plate and / or the second glass plate has a first local wedge angle fluctuation standard deviation σ1 in the image display area. The first local wedge angle fluctuation standard deviation σ1 satisfies the following condition: 3σ1≤0.08mrad / 10mm; And / or, the intermediate adhesive layer has a wedge angle, the wedge angle of the intermediate adhesive layer having a second local wedge angle fluctuation standard deviation σ2 within the image display area, the second local wedge angle fluctuation standard deviation σ2 satisfying the following condition: 3σ2≤0.15mrad / 10mm.

5. The laminated glass as described in claim 1, characterized in that, The first glass plate and / or the second glass plate with a wedge angle have a spray direction, which is vertical or horizontal.

6. The laminated glass as described in claim 1, characterized in that, The conversion efficiency of the adjustment layer for the S-polarized light is ≥90%; And / or, the thickness of the adjustment layer is 2μm~200μm; And / or, the internal reflectivity of the adjustment layer in the laminated glass is ≤2%.

7. The laminated glass as described in claim 1, characterized in that, The adjustment layer is selected from half-wave plate films.

8. The laminated glass as described in claim 7, characterized in that, The half-wave plate film is selected from at least one of polyimide-based thin film half-wave plates, liquid crystal polymer thin film half-wave plates, indium tin oxide thin film half-wave plates, quartz-based flexible thin film half-wave plates, nanocomposite thin film half-wave plates, graphene-oxide composite thin film half-wave plates, and ultrathin dielectric metasurface half-wave plates.

9. The laminated glass as described in claim 1, characterized in that, The intermediate adhesive layer includes a first adhesive layer and a second adhesive layer, and the first glass plate, the first adhesive layer, the adjustment layer, the second adhesive layer, and the second glass plate are stacked in sequence.

10. The laminated glass as described in claim 9, characterized in that, The sum of the thicknesses of the first adhesive layer and the second adhesive layer is 0.38 mm to 2.28 mm.

11. The laminated glass as claimed in claim 10, characterized in that, The thickness ratio K of the first adhesive layer to the second adhesive layer satisfies: K=1±0.

5.

12. The laminated glass as claimed in claim 1, characterized in that, The image display area is also used to receive and transmit external light, which forms a main transmitted image TL1 and a secondary transmitted image TL2. The laminated glass has a primary-to-secondary image transmittance ratio TT12, which is the ratio of the visible light transmittance of the primary image TL1 to the secondary image TL2, and the primary-to-secondary image transmittance ratio TT12 ≥ 40.

13. The laminated glass as claimed in claim 1, characterized in that, The displayed image can be observed at the eye box, which includes an upper eye box, a middle eye box, and a lower eye box corresponding to each virtual image plane. The display image corresponding to the upper eye box is tilted away from the eye box. And / or, the display image corresponding to the eye box is tilted away from the eye box; And / or, the display image corresponding to the lower eyelid box is tilted away from the eyelid box.

14. The laminated glass as described in claim 13, characterized in that, The display image corresponding to the middle eye box is tilted away from the eye box, and the tilt angle γ of the display image corresponding to the middle eye box is ≥45°.

15. The laminated glass as claimed in claim 1, characterized in that, The vertical field of view (VFOV) of the image display area is ≤5°.

16. The laminated glass as claimed in claim 1, characterized in that, The square root Gaussian curvature SRG of the first glass plate and / or the second glass plate is ≤0.00025mm. -1 .

17. The laminated glass as claimed in claim 1, characterized in that, The incident angle β of the projected light satisfies the following condition: 65°<β≤75°.

18. The laminated glass as claimed in claim 1, characterized in that, The thickness of the second glass plate is ≤2.1mm; And / or, at least within the area of ​​the image display area, the laminated glass is provided with a coloring material, the coloring material having a visible light transmittance of ≥50%, ≥60%, or ≥70%.

19. A projection system, characterized in that, The projection system includes a projection device and a laminated glass as described in any one of claims 1-18. The projection device is disposed on the side of the second glass plate away from the intermediate adhesive layer. The projection device is used to generate projection light, the projection light includes S-polarized light, and the proportion of S-polarized light in the projection light is ≥90%. The image display area is used to receive and reflect the projection light to form a display image.

20. A vehicle, characterized in that, The vehicle includes a body and a laminated glass as described in any one of claims 1-18, the laminated glass being disposed on the body.

Images