Laminated glass, projection system, and vehicle

Abstract

The application provides laminated glass, a projection system and a vehicle. The middle layer of the laminated glass comprises a coupling-in area and a coupling-out area. Projection light can be incident from a fourth surface to the coupling-in area, and after being reflected by the coupling-in area, the projection light can be reciprocally reflected between the middle layer and the fourth surface to propagate in a second glass plate; and the projection light propagating in the second glass plate can be incident to the coupling-out area, and after being reflected by the coupling-out area, the projection light can pass through the fourth surface to exit the second glass plate. By making the refractive index of the polymer layer less than the refractive index of the second glass plate and the refractive index of air less than the refractive index of the second glass plate, the second glass plate forms a light waveguide structure, so that the projection light can propagate in the second glass plate, and the coupling-in area and the coupling-out area are arranged in cooperation, so that the projection light is totally reflected in the second glass plate, thereby reducing or even eliminating ghosting phenomenon and improving the display effect of the laminated glass.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of glass, and particularly relates to a laminated glass, a projection system and a vehicle. BACKGROUND

[0002] In a vehicle, a head-up display (HUD) technology can enable a user to see an image containing driving information directly in front of a glass through light machine projection, so that the user does not need to lower his head to observe a dashboard during driving, and the driving convenience and safety are greatly improved.

[0003] A traditional head-up display technology directly uses a laminated glass as a reflection surface, and projects light into a user's eyes after one reflection through the laminated glass. Since the laminated glass is composed of an outer glass plate, an intermediate layer and an inner glass plate, the structure determines that, in addition to a main reflection surface (the fourth surface), a secondary reflection will also occur at the interfaces between the outer glass plate, the intermediate layer, the inner glass plate and the air. An image formed by the secondary reflection is called a ghost image, which generally partially overlaps with the main image, so that the actual image observed by the user appears blurred due to the overlap of the main image and the ghost image, which affects the display effect of the laminated glass and reduces the user experience. SUMMARY

[0004] In view of this, the first aspect of the present application provides a laminated glass, which comprises a first glass plate, an intermediate layer and a second glass plate, the first glass plate has a first surface and a second surface, the second glass plate has a third surface and a fourth surface, and the intermediate layer connects the second surface and the third surface.

[0005] The intermediate layer has a refractive index smaller than that of the second glass plate, and the intermediate layer comprises a coupling-in region and a coupling-out region arranged at intervals, the coupling-in region is used for receiving projection light incident from the fourth surface and changing the propagation direction of the projection light, and the coupling-out region is used for receiving the projection light propagating in the second glass plate and changing the propagation direction of the projection light.

[0006] The projection light can be incident from the fourth surface to the coupling-in region, the projection light can be reciprocally reflected between the intermediate layer and the fourth surface after being reflected by the coupling-in region, so that the projection light propagates in the second glass plate; and the projection light propagating in the second glass plate can be incident to the coupling-out region, and the projection light can pass through the fourth surface after being reflected by the coupling-out region, so as to be emitted from the second glass plate.

[0007] The intermediate layer comprises a polymer layer, a first holographic element arranged at the coupling-in region, and a second holographic element arranged at the coupling-out region, the polymer layer connects the second surface and the third surface, the polymer layer has a refractive index less than a refractive index of the second glass plate, the first holographic element and the second holographic element are fixed to the polymer layer and arranged to face the third surface, and the first holographic element and the second holographic element are arranged to be spaced apart.

[0008] The polymer layer has a refractive index ≤1.52, or ≤1.40, or ≤1.30, or ≤1.20.

[0009] The first holographic element is configured to cause the projection light to have a first angle θ1, the first angle θ1 being an included angle between a light reflected by the first holographic element and a normal direction of the second glass plate.

[0010] The first angle θ1 satisfies the following formula: θ1 ≥ arcsin(n2 / n1), wherein n1 is a refractive index of the second glass plate, and n2 is a maximum value between a refractive index of the polymer layer and a refractive index of air.

[0011] The projection light is generated by a projection device, and an incident direction of the projection light from the projection device to the fourth surface is perpendicular to the fourth surface.

[0012] The second holographic element is configured to cause the projection light to have a second angle θ2, the second angle θ2 being an included angle between a light reflected by the second holographic element and a normal direction of the second glass plate, and the projection light also has a third angle θ3, the third angle θ3 being an included angle between a light emitted from the second glass plate and the normal direction of the second glass plate.

[0013] The second angle θ2 and the third angle θ3 satisfy the following formula: sinθ2×n1=sinθ3×n3, and 1.52×sinθ2=sinθ3, wherein n1 is a refractive index of the second glass plate, and n3 is a refractive index of air.

[0014] The first holographic element has an area greater than or equal to an area of the projection light incident to the fourth surface, and / or the second holographic element has an area greater than an area of the first holographic element.

[0015] The intermediate layer further comprises an auxiliary coupling region, which is arranged on the side of the out-coupling region away from the in-coupling region; the projection light rays form crosstalk light rays after being reflected by the out-coupling region and the fourth surface in turn, and the auxiliary coupling region is used for receiving the crosstalk light rays and changing the propagation direction of the crosstalk light rays.

[0016] The crosstalk light rays can be incident on the auxiliary coupling region, and the crosstalk light rays can be reflected between the intermediate layer and the fourth surface after being reflected by the auxiliary coupling region, so as to propagate in the second glass sheet.

[0017] The intermediate layer further comprises a third holographic element arranged on the auxiliary coupling region, the third holographic element is fixed to the polymer layer and arranged to face the third surface, and the third holographic element is arranged on the side of the second holographic element away from the first holographic element.

[0018] The third holographic element is used for making the crosstalk light rays have a fourth angle θ4, the fourth angle θ4 is the included angle between the light rays reflected by the third holographic element and the normal direction of the second glass sheet.

[0019] The fourth angle θ4 satisfies the following formula: θ4≥arcsin(n2 / n1); wherein n1 is the refractive index of the second glass sheet, and n2 is the maximum value of the refractive index of the polymer layer and the refractive index of air.

[0020] The laminated glass has a light transmission region and a shielding region, the visible light transmittance of the light transmission region is ≥70%, and the visible light transmittance of the shielding region is ≤5%.

[0021] The first holographic element is arranged in the shielding region, the second holographic element and the third holographic element are arranged in the light transmission region, and the second holographic element is connected to the third holographic element.

[0022] One first holographic element, one second holographic element, and one third holographic element form a holographic element group, the laminated glass has a left-hand driving region and a right-hand driving region arranged along the length direction of the laminated glass, one holographic element group is arranged in the left-hand driving region, and another holographic element group is arranged in the right-hand driving region.

[0023] Along the height direction of the laminated glass, the height of the third holographic element is greater than the height of the second holographic element, and the height of the second holographic element is greater than the height of the first holographic element.

[0024] The first holographic element and the second holographic element have a spacing D in a height direction of the laminated glass, and the spacing D satisfies the following formula: D = 2 x n x d x tanθ1; wherein n is a positive integer, d is the thickness of the second glass sheet, and θ1 is an included angle between the reflected light of the projection light by the first holographic element and a normal direction of the second glass sheet.

[0025] The first holographic element, the second holographic element, and the third holographic element are embedded in the polymer layer, and the thicknesses of the first holographic element, the second holographic element, the third holographic element, and the polymer layer are equal.

[0026] The thickness of the polymer layer is 0.20mm-1mm, or 0.30mm-0.90mm, or 0.40mm-0.80mm.

[0027] The absolute value of the difference between the refractive index of the first holographic element and the refractive index of the polymer layer is 0-0.01;

[0028] The absolute value of the difference between the refractive index of the second holographic element and the refractive index of the polymer layer is 0-0.01;

[0029] The absolute value of the difference between the refractive index of the third holographic element and the refractive index of the polymer layer is 0-0.01.

[0030] The second aspect of the present application provides a projection system, the projection system comprising a projection device and the laminated glass provided in the first aspect of the present application, the projection device being configured to generate projection light, the projection light being incident on the fourth surface, and the laminated glass being configured to reflect the projection light to form a display image.

[0031] The third aspect of the present application provides a vehicle, the vehicle comprising a vehicle body and the projection system provided in the second aspect of the present application, the projection device of the projection system being installed inside the vehicle body, and the laminated glass of the projection system being installed at an opening of the vehicle body.

[0032] The laminated glass, projection system and vehicle provided by the application can make the second glass plate form a light waveguide structure, which can also be understood as a light guide structure, so that the projection light can propagate in the second glass plate, by setting the intermediate layer, the refractive index of the polymer layer being less than the refractive index of the second glass plate and the refractive index of the air being less than the refractive index of the second glass plate; and the direction of the projection light is changed by cooperating with the first holographic element, so that the projection light is totally reflected in the second glass plate, and then the direction of the projection light is changed by the second holographic element, so that the projection light is emitted from the second glass plate and enters the eye, thereby reducing or even eliminating the ghosting phenomenon and improving the display effect of the laminated glass. In addition, the third holographic element is also arranged to change the direction of the crosstalk light, so that the crosstalk light is totally reflected in the second glass plate, thereby avoiding the crosstalk light from being emitted at the position of the main image, further reducing or even eliminating the ghosting phenomenon, further improving the display effect of the laminated glass, and further improving the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings required to be used in the embodiments of the application will be described below.

[0034] Figure 1 A sectional view of the laminated glass provided by an embodiment of the application.

[0035] Figure 2 A partial enlarged view of Figure 1

[0036] Figure 3 Another partial enlarged view of Figure 1

[0037] Figure 4 A structural schematic view of the laminated glass provided by an embodiment of the application.

[0038] Label explanation: laminated glass 10, light transmission area 101, shielding area 102, left driving area 103, right driving area 104, first glass plate 11, first surface 111, second surface 112, intermediate layer 12, polymer layer 121, first holographic element 122, second holographic element 123, third holographic element 124, second glass plate 13, third surface 131, fourth surface 132, projection device 20. DETAILED DESCRIPTION

[0039] The following is a preferred embodiment of the application, and it should be pointed out that, for those skilled in the art, without departing from the principles of the application, a number of improvements and refinements can also be made, which are also considered within the protection scope of the application.

[0040] ​​Unless otherwise indicated or contradicted by context, terms or phrases used in this application have the following meanings:

[0041] In this application, "first", "second", and the like are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of features.

[0042] In this application, "one or more" means any one, any two, or any two or more of the listed items. Where "more" is used, it means any two or more.

[0043] The value of x in the chemical formula: if it is defined, it is defined in the defined range. If it is not defined, it can be determined according to the stoichiometric, sub-stoichiometric or super-stoichiometric deposition in the magnetron sputtering process.

[0044] Refractive index: the refractive index measured at a wavelength of 550 nm.

[0045] As shown in Figure 1 , Figure 2 , and Figure 3 , the present application provides a laminated glass 10, which comprises a first glass plate 11, an intermediate layer 12, and a second glass plate 13, the first glass plate 11 has a first face 111 and a second face 112, the second glass plate 13 has a third face 131 and a fourth face 132, and the intermediate layer 12 connects the second face 112 and the third face 131.

[0046] The refractive index of the intermediate layer 12 is less than that of the second glass plate 13, and the intermediate layer 12 comprises a coupling-in region and a coupling-out region arranged at intervals, the coupling-in region is used to receive projection light rays from the fourth face 132 and change the propagation direction of the projection light rays, and the coupling-out region is used to receive projection light rays propagating in the second glass plate 13 and change the propagation direction of the projection light rays.

[0047] Wherein, the projection light rays can be incident from the fourth face 132 to the coupling-in region, the projection light rays can be reflected between the intermediate layer 12 and the fourth face 132 after being reflected by the coupling-in region, so that the projection light rays propagate in the second glass plate 13; and the projection light rays propagating in the second glass plate 13 can be incident to the coupling-out region, the projection light rays can pass through the fourth face 132 after being reflected by the coupling-out region, so as to be emitted from the second glass plate 13.

[0048] The projection light is generated by the projection device 20, and the projection light is incident to the laminated glass 10, and the laminated glass 10 reflects the projection light to form a display image which can be observed by the person in the vehicle, especially for the driver, the image can be observed without bending down, the driver's field of view is better, and the line of sight is longer for observing the external situation, and the necessary information for assisting driving can be obtained more easily, the driving safety is greatly improved, so that the traditional instrument panel can be partially replaced or even completely replaced, and even the traditional instrument panel can be cancelled.

[0049] The display image formed by the projection light reflected by the laminated glass 10 can display vehicle driving information, various patterns or play videos, and can be used in various scenes such as welcoming, creating atmosphere, watching movies and office work. Optionally, the driving parameters including vehicle speed, engine speed, fuel consumption, tire pressure, warning information, driving mileage, etc. can be displayed, and the weather temperature, entertainment information, dynamic navigation, night vision, real scene map, etc. can also be displayed.

[0050] The first glass plate 11 is an outer glass plate of the laminated glass 10, the first glass plate 11 has a first surface 111 and a second surface 112, the first surface 111 is away from the intermediate layer 12 and contacts the environment outside the vehicle, and the second surface 112 is close to the intermediate layer 12; the second glass plate 13 is an inner glass plate of the laminated glass 10, the second glass plate 13 has a third surface 131 and a fourth surface 132, the third surface 131 is close to the intermediate layer 12, and the fourth surface 132 is away from the intermediate layer 12 and contacts the environment inside the vehicle; the intermediate layer 12 connects the second surface 112 and the third surface 131.

[0051] The first glass plate 11 is transparent glass or colored glass, the thickness of the first glass plate 11 is 1.6mm-2.1mm, and the visible light transmittance of the first glass plate 11 is greater than or equal to 80%. The second glass plate 13 is transparent glass or colored glass, the thickness of the second glass is 1.6mm-2.1mm, and the visible light transmittance of the second glass plate 13 is greater than or equal to 80%. For example, the first glass plate 11 can be transparent glass with a thickness of 2.1mm and a visible light transmittance of 89%, and the second glass plate 13 can be green glass with a thickness of 1.6mm and a visible light transmittance of 83%, or green glass with a thickness of 2.1mm and a visible light transmittance of 80%. The refractive index of the first glass plate 11 and the second glass plate 13 is 1.45-1.90, for example, 1.48, or 1.52, or 1.56, or 1.60, or 1.65, or 1.70, or 1.75, or 1.80, or 1.85, or 1.90, etc.

[0052] The refractive index of the intermediate layer 12 is less than the refractive index of the second glass sheet 13, and the refractive index of the intermediate layer 12 is less than or equal to 1.52, for example, 1.52, or 1.50, or 1.45, or 1.40, or 1.35, or 1.30, or 1.25, or 1.20, or 1.15, or 1.10, or 1.05, etc. The refractive index of air is approximately 1. The intermediate layer 12 / second glass sheet 13 / air forms a low refractive index layer / high refractive index layer / low refractive index layer, so that the second glass sheet 13 forms a light waveguide structure, which can also be understood as a light guide structure, to confine the light within a specific direction and range for propagation, so that the projection light can propagate within the second glass sheet 13.

[0053] Specifically, after the projection light enters the coupling-in area from the fourth surface 132, it is reflected by the intermediate layer 12 and then to the fourth surface 132, and then reflected by the fourth surface 132 and then to the intermediate layer 12. The projection light is repeatedly reflected between the intermediate layer 12 and the fourth surface 132, and the above process is repeated. Until the projection light is reflected by the coupling-in area and then passes through the fourth surface 132, exits the second glass sheet 13, and enters the eye, thereby reducing or even eliminating the ghosting phenomenon and improving the display effect of the laminated glass 10. The projection light is as shown in FIG. 1L. Figure 1 The propagation direction of the projection light in the second glass sheet 13 can be adjusted to cause total reflection of the projection light in the second glass sheet 13.

[0054] The laminated glass 10 in the related art uses a PVB film with a wedge angle to overlap the two reflection images as much as possible to eliminate the ghosting, but it cannot fundamentally solve the ghosting phenomenon. However, the laminated glass 10 with the holographic light waveguide structure provided in the present application can replace the wedge-shaped PVB film laminated glass 10 in the related art, effectively eliminate the influence of ghosting, have higher imaging quality, and be suitable for different shapes of laminated glass 10, and have flexibility.

[0055] The structure of the intermediate layer 12 will be described in detail below. The intermediate layer 12 includes a polymer layer 121, a first holographic element 122 arranged at the coupling-in area, and a second holographic element 123 arranged at the coupling-out area. The polymer layer 121 connects the second surface 112 and the third surface 131, and the refractive index of the polymer layer 121 is less than the refractive index of the second glass sheet 13. The first holographic element 122 and the second holographic element 123 are fixed to the polymer layer 121 and arranged to face the third surface 131, and the first holographic element 122 and the second holographic element 123 are arranged in a spaced manner.

[0056] The first holographic element 122 is configured to receive the projection light rays from the fourth surface 132 and change the propagation direction of the projection light rays so that the projection light rays propagate in the second glass plate 13. The second holographic element 123 is configured to receive the projection light rays propagating in the second glass plate 13 and change the propagation direction of the projection light rays so that the projection light rays exit the second glass plate 13. The second holographic element 123 is also configured to magnify the projection light rays.

[0057] The polymer layer 121 is disposed between the first glass plate 11 and the second glass plate 13, connecting the second surface 112 and the third surface 131. The material of the polymer layer 121 can include one or more of the following materials, such as polycarbonate (PC), polyvinyl chloride (PVC), polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), polyacrylate (PA), polymethyl methacrylate (PMMA), polyurethane (PUR), ionomer polymer film (SGP), etc. The refractive index of the polymer layer 121 is ≤1.52, and can be exemplified by 1.52, or 1.50, or 1.45, or 1.40, or 1.35, or 1.30, or 1.25, or 1.20, or 1.15, or 1.10, or 1.05, etc. Preferably, the refractive index of the polymer layer 121 is ≤1.40, more preferably, the refractive index of the polymer layer 121 is ≤1.30, and further preferably, the refractive index of the polymer layer 121 is ≤1.20. The thickness of the polymer layer 121 is 0.20mm-1mm, and can be exemplified by 0.20mm, or 0.30mm, or 0.40mm, or 0.50mm, or 0.60mm, or 0.70mm, or 0.80mm, or 0.90mm, or 1mm, etc. Preferably, the thickness of the polymer layer 121 is 0.30mm-0.90mm, and more preferably, the thickness of the polymer layer 121 is 0.40mm-0.80mm. For example, the thickness of the polymer layer 121 is 0.38mm, or 0.76mm. The specific thickness of the polymer layer 121 can be adjusted according to product requirements or user requirements.

[0058] The first holographic element 122 is a diffractive optical element, whose working principle is based on the principle of diffraction, rather than the refraction or reflection law of traditional optical elements. The first holographic element 122 can be a holographic optical element (HOE) film. The first holographic element 122 can receive the projection light rays from the fourth surface 132 and change the direction of the projection light rays, so that the projection light rays undergo total reflection in the second glass plate 13.

[0059] The first holographic element 122 is fixed to the polymer layer 121, for example, the first holographic element 122 is bonded to the polymer layer 121. The first holographic element 122 is bonded to the polymer layer 121 by using an adhesive, and the adhesive has high transparency to ensure that the visibility of the laminated glass 10 is not affected, thereby reducing the boundary feeling. The adhesive also has good adhesion, which can firmly bond the polymer layer 121 and the first holographic element 122 together, ensuring the stability and durability of the laminated glass 10. The material of the adhesive can be ethylene vinyl acetate (EVA), polyurethane (PU), etc. The first holographic element 122 is embedded in the polymer layer 121 and connected to the third surface 131, and the first holographic element 122 can also be connected to the second surface 112.

[0060] The first holographic element 122 is used to make the projection light have a first angle θ1, which is the included angle between the projection light reflected by the first holographic element 122 and the normal direction of the second glass plate 13. The first angle θ1 satisfies the following formula: θ1≥arcsin(n2 / n1); wherein n1 is the refractive index of the second glass plate 13, and n2 is the maximum value of the refractive index of the polymer layer 121 and the refractive index of air. By limiting the first holographic element 122 to make the incident angle of the projection light to be the first angle θ1, the incident angle of the projection light is greater than the critical angle of total reflection of the optical waveguide, and the projection light can propagate in the optical waveguide structure due to the total reflection effect, thereby reducing or even eliminating the ghost phenomenon and improving the display effect of the laminated glass 10.

[0061] And the projection light is generated by the projection device 20, and the incident direction of the projection light from the projection device 20 to the fourth surface 132 is perpendicular to the fourth surface 132. It can also be understood that the projection light is incident to the fourth surface 132 at an incident angle of 90°. By limiting the incident angle of the projection light from the projection device 20 to the fourth surface 132, the ghost image formed by the reflection of the incident image generated by the projection device 20 on the fourth surface 132 can be avoided. Specifically, the projection light is perpendicularly incident to the fourth surface 132 and then to the first holographic element 122.

[0062] The second holographic element 123 is a diffractive optical element, whose working principle is based on the principle of diffraction, rather than the refraction or reflection law of traditional optical elements. The second holographic element 123 can be a holographic optical element HOE film. The second holographic element 123 can receive the projection light propagating in the second glass plate 13 and change the direction of the projection light, so that the projection light exits the second glass plate 13. The second holographic element 123 can also magnify the projection light.

[0063] The second holographic element 123 is fixed to the polymer layer 121, for example, the second holographic element 123 is bonded to the polymer layer 121. The second holographic element 123 is bonded to the polymer layer 121 by using an adhesive, and the adhesive has high transparency to ensure that the visibility of the laminated glass 10 is not affected, thereby reducing the boundary feeling. The adhesive also has good adhesion, which can firmly bond the polymer layer 121 and the second holographic element 123 together, ensuring the stability and durability of the laminated glass 10. The material of the adhesive can be ethylene vinyl acetate (EVA), polyurethane (PU), etc. The second holographic element 123 is embedded in the polymer layer 121 and connected to the third surface 131, and the second holographic element 123 can also be connected to the second surface 112.

[0064] The second holographic element 123 is used to make the projection light have a second angle θ2, which is the included angle between the light reflected by the second holographic element 123 and the normal direction of the second glass plate 13. The projection light also has a third angle θ3, which is the included angle between the light emitted from the second glass plate 13 and the normal direction of the second glass plate 13. The second angle θ2 and the third angle θ3 satisfy the following formula: sinθ2×n1=sinθ3×n3, and 1.52×sinθ2=sinθ3; where n1 is the refractive index of the second glass plate 13, and n3 is the refractive index of air. The second holographic element 123 changes the direction of the projection light to make the projection light have the second angle θ2, which eliminates the total reflection of the projection light in the second glass plate 13, so that it is emitted from the second glass plate 13 and enters the human eye. The changed angle is related to the position of the human eye and has flexibility. At the same time, the second holographic element 123 also plays a role in magnifying the image, further improving the display effect of the laminated glass 10.

[0065] The area of the first holographic element 122 is greater than or equal to the area of the projection light incident to the fourth surface 132. The area of the first holographic element 122 matches the area of the projection light projected onto the fourth surface 132, which is conducive to the first holographic element 122 being able to receive and reflect more projection light, thereby improving the display effect of the laminated glass 10.

[0066] And / or, the area of the second holographic element 123 is greater than the area of the first holographic element 122, which is conducive to the second holographic element 123 receiving and reflecting more projection light, thereby improving the display effect of the laminated glass 10.

[0067] In an embodiment, the intermediate layer 12 further comprises an auxiliary coupling region arranged on a side of the out-coupling region away from the in-coupling region; the projection light rays form crosstalk light rays after being reflected by the out-coupling region and the fourth surface 132 in sequence, and the auxiliary coupling region is configured to receive the crosstalk light rays and change the propagation direction of the crosstalk light rays.

[0068] The crosstalk light rays can be incident on the auxiliary coupling region, and the crosstalk light rays can be reflected between the intermediate layer 12 and the fourth surface 132 after being reflected by the auxiliary coupling region, so that the crosstalk light rays propagate in the second glass plate 13. Figure 1 The crosstalk light rays are as shown in L2.

[0069] The embodiment cooperates the out-coupling region with the auxiliary coupling region to make the crosstalk light rays propagate in the second glass plate 13, so that the crosstalk light rays are totally reflected in the second glass plate 13, the crosstalk light rays are prevented from being transmitted out at the position of the main image, the ghosting phenomenon is further reduced or even eliminated, the display effect of the laminated glass 10 is further improved, and the user experience is further improved.

[0070] The intermediate layer 12 further comprises a third holographic element 124 arranged on the auxiliary coupling region, the third holographic element 124 is fixed to the polymer layer 121 and faces the third surface 131, and the third holographic element 124 is arranged on a side of the second holographic element 123 away from the first holographic element 122.

[0071] The projection light rays form crosstalk light rays after being reflected by the second holographic element 123 and the fourth surface 132 in sequence, and the third holographic element 124 is configured to receive the crosstalk light rays and change the propagation direction of the crosstalk light rays, so that the crosstalk light rays propagate in the second glass plate 13.

[0072] The third holographic element 124 is a diffractive optical element, whose working principle is based on the diffraction principle, rather than the refraction or reflection law of traditional optical elements. The third holographic element 124 can be a holographic optical element HOE film. The third holographic element 124 can receive the crosstalk light rays and change the direction of the crosstalk light rays, so that the crosstalk light rays are totally reflected in the second glass plate 13.

[0073] The third holographic element 124 is fixed to the polymer layer 121, for example, by bonding the third holographic element 124 to the polymer layer 121. An adhesive with high transparency is used to bond the third holographic element 124 to the polymer layer 121, ensuring that the visibility of the laminated glass 10 is not affected, thereby reducing the sense of boundary. The adhesive also has good adhesion, firmly bonding the polymer layer 121 and the third holographic element 124 together, ensuring the stability and durability of the laminated glass 10. The adhesive material can be vinyl acetate (EVA), polyurethane (PU), etc. The third holographic element 124 is embedded in the polymer layer 121 and connected to the third surface 131. The third holographic element 124 can also be connected to the second surface 112. The third holographic element 124 is farther away from the first holographic element 122 than the second holographic element 123, and the third holographic element 124 is connected to the second holographic element 123.

[0074] The third holographic element 124 is used to give the crosstalk light a fourth angle θ4, which is the angle between the light reflected by the third holographic element 124 and the normal direction of the second glass plate 13. The fourth angle θ4 satisfies the following formula: θ4≥arcsin(n2 / n1); where n1 is the refractive index of the second glass plate 13, and n2 is the maximum value between the refractive index of the polymer layer 121 and the refractive index of air.

[0075] Because the portion of the projected light reflected by the second holographic element 123 is reflected by the fourth surface 132, crosstalk light is formed, which causes ghosting. Therefore, this application limits the incident angle of the crosstalk light to the fourth angle θ4 by the third holographic element 124, making the incident angle of the crosstalk light greater than the critical angle of total internal reflection in the optical waveguide. Due to the total internal reflection effect, the crosstalk light can propagate within the optical waveguide structure, thereby preventing the crosstalk light from escaping at the position of the main image, further reducing or even eliminating ghosting, further improving the display effect of the laminated glass 10, and further enhancing the user experience.

[0076] like Figure 4 As shown, Figure 4 This is a schematic diagram of the laminated glass 10 viewed from inside a vehicle. The laminated glass 10 has a light-transmitting area 101 and a shielding area 102. The visible light transmittance of the light-transmitting area 101 is ≥70%, and the visible light transmittance of the shielding area 102 is ≤5%. The first holographic element 122 is disposed in the shielding area 102, and the second holographic element 123 and the third holographic element 124 are both disposed in the light-transmitting area 101. The second holographic element 123 is connected to the third holographic element 124.

[0077] The shielding area 102 is also commonly referred to as a black border area. Preferably, the shielding area 102 is a bottom shielding area arranged below the light-transmitting area 101. Optionally, the laminated glass 10 further comprises a shielding layer arranged on the second face 112 and / or the fourth face 132, the shielding layer being arranged in the shielding area 102. The shielding layer can shield ambient light, avoid unnecessary interference of the line of sight, improve the contrast between the display image and the display background, and achieve a higher color gamut, so that the image display is clearer. The material of the shielding layer is selected from at least one of a dark ink, an opaque polymer film, and a light-adjustable film.

[0078] In addition, as shown in Figure 4 , one of the first holographic elements 122, one of the second holographic elements 123, and one of the third holographic elements 124 form a holographic element group, and the laminated glass 10 has a left driving area 103 and a right driving area 104 arranged along the length direction of the laminated glass 10. One of the holographic element groups is arranged in the left driving area 103, and the other holographic element group is arranged in the right driving area 104. By arranging two holographic element groups in the left driving area 103 and the right driving area 104 respectively, the display image formed by the projected light can be clearly observed by the user in the left driving area 103 and the user in the right driving area 104, the ghosting phenomenon is reduced or even eliminated, and the display effect of the laminated glass 10 is improved.

[0079] In the height direction of the laminated glass 10, the height (as shown by H3 in Figure 4 ) of the third holographic element 124 is greater than the height (as shown by H2 in Figure 4 ) of the second holographic element 123, and the height (as shown by H2 in Figure 4 ) of the second holographic element 123 is greater than the height (as shown by H1 in Figure 4 ) of the first holographic element 122.

[0080] Since the projected light irradiated onto the first holographic element 122 may not be completely irradiated on the central position of the first holographic element 122, but may be irradiated on the edge thereof, in order to ensure that the light reflected by the first holographic element 122 is completely received by the second holographic element 123, by making the height of the second holographic element 123 greater than the height of the first holographic element 122, the second holographic element 123 can receive more projected light.

[0081] In addition, since the second holographic element 123 has the function of magnifying the image, in order to completely receive the light reflected back by the fourth face 132, by making the height of the third holographic element 124 greater than the height of the second holographic element 123, the third holographic element 124 can receive more crosstalk light, the ghosting phenomenon is reduced or even eliminated, and the display effect of the laminated glass 10 is improved.

[0082] The specific positions, heights, and widths of the first holographic element 122, the second holographic element 123, and the third holographic element 124 need to be determined according to the installation position of the projection device 20, the FOV field of view, and the eyebox position of different vehicle models, and are not limited herein.

[0083] The first holographic element 122, the second holographic element 123, and the third holographic element 124 are flexible. The first holographic element 122, the second holographic element 123, and the third holographic element 124 can be matched with the curved glass plate. In addition, the curved laminated glass 10 can cancel out the enlargement and reduction of the image through one reflection between the third surface 131 and the fourth surface 132. The fourth surface 132 can be regarded as a convex mirror, and the third surface 131 can be regarded as a concave mirror, so as not to affect the display effect of the laminated glass 10.

[0084] The first holographic element 122 and the second holographic element 123 have a spacing D in the height direction of the laminated glass 10, and the spacing D satisfies the following formula: D = 2 x n x d x tan θ1; wherein n is a positive integer, d is the thickness of the second glass plate 13, and θ1 is the included angle between the reflected light of the projection light through the first holographic element 122 and the normal direction of the second glass plate 13. The spacing between the first holographic element 122 and the second holographic element 123 is limited by the above formula, so as to ensure that the projection light reflected by the first holographic element 122 can be received by the second holographic element 123, so that the projection light can be emitted from the second glass plate 13 and enter the eye, thereby reducing or even eliminating the ghost phenomenon and improving the display effect of the laminated glass 10.

[0085] The first holographic element 122, the second holographic element 123, and the third holographic element 124 are embedded in the polymer layer 121, and the thicknesses of the first holographic element 122, the second holographic element 123, the third holographic element 124, and the polymer layer 121 are equal. By limiting the thicknesses of the first holographic element 122, the second holographic element 123, the third holographic element, and the polymer layer 121 to be equal, the bulging phenomenon of the laminated glass 10 can be avoided, and the reliability of the laminated glass 10 can be improved.

[0086] The absolute value of the difference between the refractive index of the first holographic element 122 and the refractive index of the polymer layer 121 is 0-0.01. The absolute value of the difference between the refractive index of the first holographic element 122 and the refractive index of the polymer layer 121 can be 0.001, or 0.002, or 0.003, or 0.004, or 0.005, or 0.006, or 0.007, or 0.008, or 0.009, or 0.01, etc.

[0087] And / or, the absolute value of the difference between the refractive index of the second holographic element 123 and the refractive index of the polymer layer 121 is 0-0.01. The absolute value of the difference between the refractive index of the second holographic element 123 and the refractive index of the polymer layer 121 can be specifically exemplified as 0.001, or 0.002, or 0.003, or 0.004, or 0.005, or 0.006, or 0.007, or 0.008, or 0.009, or 0.01, etc.

[0088] And / or, the absolute value of the difference between the refractive index of the third holographic element 124 and the refractive index of the polymer layer 121 is 0-0.01. The absolute value of the difference between the refractive index of the third holographic element 124 and the refractive index of the polymer layer 121 can be specifically exemplified as 0.001, or 0.002, or 0.003, or 0.004, or 0.005, or 0.006, or 0.007, or 0.008, or 0.009, or 0.01, etc.

[0089] By limiting the absolute value of the difference between the refractive index of the polymer layer 121 and the refractive index of the first holographic element 122, the second holographic element 123 and the third holographic element 124, the polymer layer 121 can better cooperate with each holographic element, better limit the propagation of the projection light in a specific direction and range, thereby reducing or even eliminating ghosting phenomenon and improving the display effect of the laminated glass 10.

[0090] The present application can fundamentally solve the ghosting phenomenon caused by the reflection of the image on the first and fourth surfaces of the laminated glass twice by setting the first holographic element, the second holographic element, the third holographic element and the polymer layer in cooperation. The image is reflected into the optical waveguide structure only by the first holographic element, the image is propagated through the optical waveguide structure, and finally the image is emitted by the second holographic element and enters the human eye. The remaining reflected light continues to be limited in the second glass plate by the third holographic element and is emitted at a position that does not affect the main image, thereby significantly improving the display effect of the laminated glass and improving the user experience.

[0091] The present application provides a projection system, which comprises a projection device and a laminated glass provided by the present application. The projection device is used to generate projection light, the projection light is incident on the fourth surface, and the laminated glass reflects the projection light to form a display image.

[0092] The wavelength of the projection light can be in the range of 380nm to 780nm. The projection light can contain at least 80% P-polarized light. The higher the proportion of P-polarized light in the projection light, the more conducive it is to meet the use requirements of drivers wearing sunglasses and the easier it is to eliminate the visual ghosting phenomenon of the display image.

[0093] The application provides a vehicle, which comprises a vehicle body and the projection system provided by the application, wherein the projection device of the projection system is installed in the interior of the vehicle body, and the laminated glass of the projection system is installed at the opening of the vehicle body.

[0094] When the laminated glass is installed on the vehicle, it is preferably used as the front windshield of the vehicle. However, it is not limited thereto, and the laminated glass can also be used as the rear windshield or the side window glass, thereby providing more display scene applications for the vehicle.

[0095] The above provides the content provided by the embodiment of the application, and the principle and embodiment of the application are described and explained. The above description is only used to help understand the method and core idea of the application; meanwhile, for the general skilled in the art, according to the idea of the application, the specific embodiment and application range will be changed, and the above description should not be understood as the limitation of the application.

Claims

1. A laminated glass, characterized by, The laminated glass comprises a first glass plate, an intermediate layer, and a second glass plate, the first glass plate has a first surface and a second surface, the second glass plate has a third surface and a fourth surface, and the intermediate layer connects the second surface and the third surface; The intermediate layer has a refractive index less than that of the second glass plate, and comprises a plurality of spaced apart in-coupling regions and out-coupling regions, the in-coupling regions are configured to receive projection light rays from the fourth surface and change the propagation direction of the projection light rays, and the out-coupling regions are configured to receive the projection light rays propagating in the second glass plate and change the propagation direction of the projection light rays; The projection light rays can be incident from the fourth surface to the in-coupling regions, the projection light rays can be reflected between the intermediate layer and the fourth surface after being reflected by the in-coupling regions, so that the projection light rays propagate in the second glass plate; and the projection light rays propagating in the second glass plate can be incident to the out-coupling regions, the projection light rays can pass through the fourth surface after being reflected by the out-coupling regions, so as to be emitted from the second glass plate.

2. Laminated glass according to claim 1, characterized in that The intermediate layer comprises a polymer layer, a first holographic element arranged at the in-coupling regions, and a second holographic element arranged at the out-coupling regions, the polymer layer connects the second surface and the third surface, the polymer layer has a refractive index less than that of the second glass plate, the first holographic element and the second holographic element are fixed to the polymer layer and arranged to face the third surface, and the first holographic element and the second holographic element are spaced apart.

3. Laminated glass according to claim 2, characterized in that The refractive index of the polymer layer is less than or equal to 1.

52.

4. The laminated glass according to claim 2, wherein The refractive index of the polymer layer is less than or equal to 1.

40.

5. The laminated glass according to claim 2, wherein The refractive index of the polymer layer is less than or equal to 1.

30.

6. The laminated glass according to claim 2, wherein The refractive index of the polymer layer is less than or equal to 1.

20.

7. The laminated glass according to claim 2, wherein The first holographic element is configured to make the projection light rays have a first angle θ1, the first angle θ1 is the included angle between the light rays reflected by the first holographic element and the normal direction of the second glass plate; The first angle θ1 satisfies the formula: θ1≥arcsin(n2 / n1); wherein n1 is the refractive index of the second glass plate, and n2 is the maximum value between the refractive index of the polymer layer and the refractive index of air.

8. The laminated glass according to claim 2, wherein The projection light rays are generated by a projection device, and the incident direction of the projection light rays from the projection device to the fourth surface is perpendicular to the fourth surface.

9. The laminated glass of claim 2, wherein The second holographic element is configured to make the projection light rays have a second angle θ2, the second angle θ2 is the included angle between the light rays reflected by the second holographic element and the normal direction of the second glass plate, and the projection light rays also have a third angle θ3, the third angle θ3 is the included angle between the light rays emitted from the second glass plate and the normal direction of the second glass plate; The second angle θ2 and the third angle θ3 satisfy the formula: sinθ2×n1=sinθ3×n3, and 1.52×sinθ2=sinθ3; wherein n1 is the refractive index of the second glass plate, and n3 is the refractive index of air.

10. The laminated glass according to claim 2, wherein The area of the first holographic element is greater than or equal to the area of the projection light incident to the fourth surface; and / or, the area of the second holographic element is greater than the area of the first holographic element.

11. The laminated glass according to claim 2, wherein The intermediate layer further comprises an auxiliary coupling region arranged on the side of the out-coupling region away from the in-coupling region; the projection light forms crosstalk light after being reflected by the out-coupling region and the fourth surface in turn, and the auxiliary coupling region is used for receiving the crosstalk light and changing the propagation direction of the crosstalk light; The crosstalk light can be incident to the auxiliary coupling region, and the crosstalk light can be reciprocally reflected between the intermediate layer and the fourth surface after being reflected by the auxiliary coupling region, so that the crosstalk light propagates in the second glass plate.

12. Laminated glass according to claim 11, characterized in that The intermediate layer further comprises a third holographic element arranged on the auxiliary coupling region, the third holographic element is fixed to the polymer layer and arranged facing the third surface, and the third holographic element is arranged on the side of the second holographic element away from the first holographic element.

13. Laminated glass according to claim 12, characterized in that The third holographic element is used to make the crosstalk light have a fourth angle θ4, the fourth angle θ4 is the included angle between the light reflected by the third holographic element and the normal direction of the second glass plate; The fourth angle θ4 satisfies the following formula: θ4≥arcsin(n2 / n1); wherein n1 is the refractive index of the second glass plate, and n2 is the maximum value of the refractive index of the polymer layer and the refractive index of air.

14. The laminated glass of claim 12, wherein The laminated glass has a light transmission region and a shielding region, the visible light transmittance of the light transmission region is ≥70%, and the visible light transmittance of the shielding region is ≤5%; The first holographic element is arranged in the shielding region, and the second holographic element and the third holographic element are arranged in the light transmission region, and the second holographic element is connected to the third holographic element.

15. The laminated glass of claim 12, wherein One first holographic element, one second holographic element, and one third holographic element form a holographic element group, the laminated glass has a left-hand driving region and a right-hand driving region arranged along the length direction of the laminated glass, one holographic element group is arranged in the left-hand driving region, and another holographic element group is arranged in the right-hand driving region.

16. The laminated glass of claim 12, wherein Along the height direction of the laminated glass, the height of the third holographic element is greater than the height of the second holographic element, and the height of the second holographic element is greater than the height of the first holographic element.

17. The laminated glass of claim 12, wherein Along the height direction of the laminated glass, the first holographic element and the second holographic element have a spacing D, and the spacing D satisfies the following formula: D=2×n×d×tanθ1; wherein n is a positive integer, d is the thickness of the second glass plate, and θ1 is the included angle between the light reflected by the first holographic element and the normal direction of the second glass plate.

18. The laminated glass of claim 12, wherein The first holographic element, the second holographic element, and the third holographic element are embedded in the polymer layer, and the thicknesses of the first holographic element, the second holographic element, the third holographic element, and the polymer layer are equal.

19. The laminated glass of claim 18, wherein The thickness of the polymer layer is 0.20mm~1mm.

20. The laminated glass of claim 18, wherein The thickness of the polymer layer is 0.30mm~0.90mm.

21. The laminated glass of claim 18, wherein The thickness of the polymer layer is 0.40mm~0.80mm.

22. The laminated glass of claim 12, wherein The absolute value of the difference between the refractive index of the first holographic element and the refractive index of the polymer layer is 0~0.01; The absolute value of the difference between the refractive index of the second holographic element and the refractive index of the polymer layer is 0~0.01; The absolute value of the difference between the refractive index of the third holographic element and the refractive index of the polymer layer is 0~0.

01.

23. A projection system, characterized by The projection system comprises a projection device and the laminated glass as claimed in any one of claims 1-22, the projection device is used to generate projection light, the projection light is shot to the fourth surface, and the laminated glass reflects the projection light to form a display image.

24. A vehicle characterized by The vehicle comprises a vehicle body and the projection system as claimed in claim 23, the projection device of the projection system is installed in the interior of the vehicle body, and the laminated glass of the projection system is installed at the opening of the vehicle body.

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