Transparent projection medium, projection system and vehicle

Abstract

The embodiment of the utility model relates to the technical field of optics, and provides a transparent projection medium, a projection system and a vehicle. The transparent projection medium comprises a first glass layer, a second glass layer and a P polarized light reflecting layer. The P polarized light reflecting layer is located between the first glass layer and the second glass layer. The P polarized light reflecting layer comprises a metal layer and a dielectric layer which are stacked. The dielectric layer comprises a high-refractive-index layer and a low-refractive-index layer which are stacked, and the refractive index of the low-refractive-index layer is smaller than that of the high-refractive-index layer.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a transparent projection medium, a projection system and a vehicle. Background Art

[0002] At present, the projection system that can realize transparent display usually includes a projection light source and a transparent projection medium. The projection light source emits projection light to the transparent projection medium, and the transparent projection medium reflects the projection light to realize imaging. Among them, the transparent projection medium can not only reflect the projection light, but also transmit the ambient light, so that the viewer on the display side of the transparent projection medium can not only see the projected image formed by the projection light, but also see the environment on the side of the transparent projection medium away from the display side, thereby achieving the effect of transparent display. Specifically, when the projection system is applied to the automotive field, the vehicle glass (such as the front windshield) can be used as a transparent projection medium to display images. Among them, in the traditional projection system, the projection light emitted by the projection light source is usually pure S-polarized light or more than 50% of the projection light is S-polarized light. Since the S-polarized light is reflected at the inner surface from the air to the glass and the outer surface from the glass to the air, two offset images are generated, which is the so-called ghosting phenomenon. Utility Model Content

[0003] In a first aspect, the present application provides a transparent projection medium. The transparent projection medium comprises a first glass layer, a second glass layer and a P-polarized light reflecting layer. The P-polarized light reflecting layer is located between the first glass layer and the second glass layer. The P-polarized light reflecting layer comprises a stacked metal layer and a dielectric layer. The dielectric layer comprises a stacked high refractive index layer and a low refractive index layer, wherein the refractive index of the low refractive index layer is less than the refractive index of the high refractive index layer.

[0004] In the transparent projection medium of the first aspect of the present application, P-polarized light is used for projection, and the reflectivity of P-polarized light incident on the interface between glass and air is low, especially when incident near the Brewster angle, basically no reflection occurs, and the P-polarized light reflection layer can reflect part of the P-polarized light, thereby reducing the degree of ghosting.

[0005] In addition, the P polarized light reflection layer is located between the first glass layer and the second glass layer, so that the P polarized light reflection layer is not exposed to the air, and the performance is more stable. Moreover, a metal layer is provided in the P polarized light reflection layer, and the dielectric layer includes a high refractive index layer and a low refractive index layer stacked. By comprehensively considering the effects of the first glass layer, the second glass layer, the metal layer, and the dielectric layer on light, compared with the structure in which the P polarized light reflection layer is composed of a pure dielectric layer, it is beneficial to reduce the number of layers of the P polarized light reflection layer while ensuring the optical effect of the P polarized light reflection layer, and reduce the total thickness of the P polarized light reflection layer.

[0006] In some embodiments, the metal layer is a nanosilver layer, and the thickness thereof is in the range of 5 nm to 20 nm.

[0007] In some embodiments, the dielectric layer includes a high refractive index layer and a low refractive index layer, the low refractive index layer and the high refractive index layer are sequentially stacked on the nanosilver layer, the thickness of the high refractive index layer ranges from 30nm to 45nm, and the thickness of the low refractive index layer ranges from 0.5nm to 5nm.

[0008] In some embodiments, the dielectric layer includes two high refractive index layers and two low refractive index layers, the two high refractive index layers are defined as the first high refractive index layer and the second high refractive index layer, the two low refractive index layers are defined as the first low refractive index layer and the second low refractive index layer, the first high refractive index layer, the first low refractive index layer, the second high refractive index layer and the second low refractive index layer are sequentially stacked on the nanosilver layer, the thickness range of the first high refractive index layer is 30nm to 45nm, the thickness range of the first low refractive index layer is 20nm to 35nm, the thickness range of the second high refractive index layer is 7nm to 12nm, and the thickness range of the second low refractive index layer is 55nm to 66nm.

[0009] In some embodiments, the dielectric layer includes three high refractive index layers and three low refractive index layers, and the three high refractive index layers are defined as the first high refractive index layer, the second high refractive index layer and the third high refractive index layer, and the three low refractive index layers are defined as the first low refractive index layer, the second low refractive index layer and the third low refractive index layer, and the first high refractive index layer, the first low refractive index layer, the second high refractive index layer, the second low refractive index layer, the third high refractive index layer and the third low refractive index layer are sequentially stacked on the nanosilver layer, the thickness range of the first high refractive index layer is 25nm~28nm, the thickness range of the first low refractive index layer is 120nm~130nm, the thickness range of the second high refractive index layer is 5nm~13nm, the thickness range of the second low refractive index layer is 62nm~70nm, the thickness range of the third high refractive index layer is 5nm~28nm, and the thickness range of the third low refractive index layer is 12nm~39nm.

[0010] In some embodiments, the P-polarized light reflecting layer further includes a transition layer, which is located on a side of the nano-silver layer away from the dielectric layer, and is used to improve the morphology of the nano-silver layer.

[0011] In some embodiments, the P-polarized light reflecting layer further includes an isolation layer, which is located between the nano-silver layer and the dielectric layer. The isolation layer is used to prevent the nano-silver layer from being oxidized when the dielectric layer is prepared.

[0012] In some embodiments, the transition layer has a thickness ranging from 0.5 nm to 5 nm.

[0013] In some embodiments, the thickness of the isolation layer ranges from 0.5 nm to 5 nm.

[0014] In some embodiments, the total number of P-polarized light reflecting layers is less than 10.

[0015] In some embodiments, the total thickness of the P-polarized light reflecting layer is less than 200 nm.

[0016] In some embodiments, the haze of the transparent projection medium is less than 2%.

[0017] In some embodiments, the reflectivity of the transparent projection medium to P-polarized light is 15% to 25%.

[0018] In some embodiments, the reflectivity range of the transparent projection medium to P-polarized light incident at an incident angle of 60° within a wavelength range of 450 nm-650 nm is less than or equal to 3%.

[0019] In some embodiments, the transmittance of the transparent projection medium to natural light is 70% to 90%.

[0020] In some embodiments, the transparent projection medium further includes a bonding layer, and the P-polarized light reflecting layer is formed on a surface of the first glass layer and is bonded to the second glass layer through the bonding layer.

[0021] In some embodiments, the transparent projection medium further includes a bonding layer, and the P-polarized light reflecting layer is formed on a surface of the second glass layer and is bonded to the first glass layer through the bonding layer.

[0022] In some embodiments, the transparent projection medium further includes a first bonding layer, a second bonding layer and a substrate layer. The P-polarized light reflecting layer is formed on the surface of the substrate layer and is bonded to the first glass layer through the first bonding layer. The side of the substrate layer facing away from the P-polarized light reflecting layer is bonded to the second glass layer through the second bonding layer.

[0023] In some embodiments, the transparent projection medium further includes a functional layer, which is stacked with the P-polarized light reflecting layer, and the functional layer includes at least one of a conductive layer, an anti-ultraviolet layer, and an explosion-proof layer.

[0024] The second aspect of the present application provides a projection system. The projection system includes a projection light source and the transparent projection medium provided in the first aspect of the present application. The projection light source is used to emit projection light containing P polarized light. The transparent projection medium is used to receive and reflect the projection light.

[0025] The projection system of the second aspect of the present application has at least the same advantages as the transparent projection medium provided by the first aspect of the present application, which will not be described in detail.

[0026] The third aspect of the present application provides a vehicle, which includes the projection system provided by the second aspect of the present application.

[0027] The vehicle of the third aspect of the present application has at least the same advantages as the projection system of the second aspect of the present application, which will not be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of how the reflectivity of P-polarized light and S-polarized light changes with the incident angle when light is incident from air to glass.

[0029] Figure 2 FIG. 1 is a schematic diagram of imaging of a projection system according to an embodiment of the present application.

[0030] Figure 3 It is a schematic structural diagram of a transparent projection medium according to the first embodiment of the present application.

[0031] Figure 4 It is a schematic structural diagram of a transparent projection medium according to the second embodiment of the present application.

[0032] Figure 5 It is a schematic structural diagram of a transparent projection medium according to the third embodiment of the present application.

[0033] Figure 6 It is a schematic structural diagram of a transparent projection medium according to the fourth embodiment of the present application.

[0034] Figure 7 This is a schematic diagram of the specific structure of the transparent projection medium of the first embodiment of the present application.

[0035] Figure 8 for Figure 7 The transparent projection medium shown is a reflection spectrum diagram of P polarized light when the incident angle is 60°.

[0036] Fig. 9 for Figure 7 The transparent projection medium shown is a transmission spectrum of natural light when the incident angle is 0°.

[0037] Fig.10 This is another specific structural schematic diagram of the transparent projection medium of the first embodiment of the present application.

[0038] Fig.11 for Fig.10 The transparent projection medium shown is a reflection spectrum diagram of P polarized light when the incident angle is 60°.

[0039] Fig.12 for Fig.10 The spectrum diagram of the transmittance of natural light of the transparent projection medium shown is when the incident angle is 0°.

[0040] Fig.13 This is another specific structural schematic diagram of the transparent projection medium of the first embodiment of the present application.

[0041] Fig.14 for Fig.13 The transparent projection medium shown is a reflection spectrum diagram of P polarized light when the incident angle is 60°.

[0042] Fig.15 for Fig.13 The transparent projection medium shown is a transmission spectrum of natural light when the incident angle is 0°.

[0043] Description of main component symbols:

[0044] Projection System 1000

[0045] Projection light source 110

[0046] Transparent projection medium 100, 200, 300, 400, 500, 200a, 200b, 200c

[0047] First glass layer 101, 201, 301, 401, 501

[0048] P-polarized light reflecting layers 102, 202, 302, 402, 502, 202a, 202b, 202b

[0049] Metal layer 10

[0050] Dielectric layers 20a, 20b, 20c

[0051] High refractive index layer 21

[0052] First high refractive index layer 21a

[0053] Second high refractive index layer 21b

[0054] The third high refractive index layer 21c

[0055] Low refractive index layer 22

[0056] First low refractive index layer 22a

[0057] Second low refractive index layer 22b

[0058] The third low refractive index layer 22c

[0059] Transition layer 30

[0060] Isolation layer 40

[0061] Second glass layer 103, 203, 303, 403, 503

[0062] Lamination layers 204, 304

[0063] First laminating layer 404a, 504a

[0064] Second laminating layers 404b, 504b

[0065] Base material layers 405, 505

[0066] Projection light L1

[0067] Reflected light L2

[0068] Virtual Image V

[0069] Human Eye DETAILED DESCRIPTION

[0070] In-vehicle head-up display (HUD) uses a projector / image source to project some information onto the windshield, which is reflected by the windshield to the human eye and perceived by the driver as a virtual image in front. Generally, the projection light emitted by the projector / image source is S-polarized light, and the incident angle is generally 50° to 70°. Figure 1 As shown in the gray dotted box. More, the projected light illuminates the windshield at an incident angle of about 60°. The Brewster angle of air and glass is 56° (the refractive index of air is 1, and the refractive index of glass is 1.5), that is, the incident angle of the projected light on the windshield is near the Brewster angle. Figure 1 The figure shows how the reflectivity of S-polarized light and P-polarized light changes with the incident angle when the light is incident from air to glass. It can be seen that when the incident angle of the projected light is near the Brewster angle, part of the S-polarized light is reflected by the surface, and almost all of the P-polarized light is transmitted.

[0071] When the projection light is pure S-polarized light, or more than 50% is S-polarized light, the projection light will be reflected on the inner glass surface and the inner surface of the outer glass at the same time, resulting in ghosting. There are two ways to eliminate ghosting. One is to set a wedge film between the inner glass and the outer glass. This method is expensive and very sensitive to the height of the eye box and the thickness error of the wedge film. The second method is to set an S-polarized light reflection layer on the inner surface of the inner glass. However, since the S-polarized light reflection layer is exposed to the air, it is easy to age and can only reduce the brightness of the secondary image to a limited extent, and the secondary image will still be perceived by the driver.

[0072] When the projection light is pure P-polarized light, or more than 50% is P-polarized light, the way to eliminate ghosting is to set a P-polarized light reflection layer in the windshield. In the P-polarized light HUD, the P-polarized light reflection layer is set on the inner surface of the inner glass, that is, the P-polarized light reflection layer is exposed to the air, and the P-polarized light reflection layer is completely composed of a complex all-dielectric reflection layer, which is thick (the total thickness is as high as about 400nm to 600nm), and the efficiency is low.

[0073] In this regard, the embodiments of the present application provide a transparent projection medium, a projection system using the transparent projection medium, and a vehicle. The following description is made by taking the transparent projection medium as vehicle glass and the projection system as a HUD as an example. The vehicle glass may be a front windshield, a side window glass, or a top window glass, etc. In other embodiments, the application scenario of the transparent projection medium may also be a product that can be used as a projection display carrier, such as a display window, a display cabinet, and a screen.

[0074] like Figure 2 As shown, the projection system 1000 includes a transparent projection medium 100 and a projection light source 110. The projection light source 110 is used to emit a projection light L1 containing P polarized light. In some embodiments, the proportion of P polarized light in the projection light L1 is greater than 50%, and more preferably, greater than 70%. After receiving the projection light L1, the transparent projection medium 100 reflects the projection light L1 to the human eye E, so that the driver can perceive it as a virtual image V in front. The virtual image V can display information such as speed, navigation, speed, mileage, fuel level, remaining power, warning information, prompt information, weather information, video, etc., so that the driver can obtain driving information without taking his eyes off the road, thereby avoiding visual fatigue and distraction caused by the driver's eyes switching back and forth between the road and the instrument.

[0075] It is understandable that the projection system 1000 further includes one or more reflective elements (not shown), which may be curved mirrors or plane mirrors. The projection light L1 emitted by the projection light source 110 is reflected by the reflective elements to the transparent projection medium 100 .

[0076] Specifically, the transparent projection medium 100 includes a first glass layer 101, a P-polarized light reflecting layer 102, and a second glass layer 103. The P-polarized light reflecting layer 102 is located between the first glass layer 101 and the second glass layer 103. Specifically in the application scenario of HUD, the side where the first glass layer 101 is located is inside the vehicle, and the side where the second glass layer 103 is located is outside the vehicle, so the first glass layer 101 is also called inner glass, and the second glass layer 103 is also called outer glass.

[0077] When the projection light L1 is incident on the surface of the first glass layer 101, most of the projection light L1 passes through the first glass layer 101 and is incident on the P-polarized light reflecting layer 102. After being reflected at the P-polarized light reflecting layer 102, it is emitted from the first glass layer 101 and forms reflected light L2 to enter the human eye E. Since the reflectivity of the P-polarized light incident on the glass-air interface is low, especially when it is incident near the Brewster angle, basically no reflection occurs, and the P-polarized light in the projection light L1 is reflected at the P-polarized light reflecting layer 102, the degree of ghosting is greatly reduced.

[0078] The following combination Figures 3 to 6The specific structure of the transparent projection medium 100 according to different embodiments is described in detail.

[0079] In some embodiments, such as Figure 3 As shown, the transparent projection medium 200 includes a first glass layer 201, a P-polarized light reflecting layer 202, and a second glass layer 203. The P-polarized light reflecting layer 202 is located between the first glass layer 201 and the second glass layer 203. The transparent projection medium 200 also includes a bonding layer 204. The P-polarized light reflecting layer 202 is directly formed on the surface of the first glass layer 201 (or directly formed on the surface of the inner glass layer) by, for example, vacuum coating, and then a bonding adhesive is applied on the second glass layer 203 and / or the P-polarized light reflecting layer 202 as the bonding layer 204, so as to bond the first glass layer 201 formed with the P-polarized light reflecting layer 202 to the second glass layer 203.

[0080] In some embodiments, such as Figure 4 As shown, the transparent projection medium 300 includes a first glass layer 301, a P-polarized light reflecting layer 302, and a second glass layer 303. The P-polarized light reflecting layer 302 is located between the first glass layer 301 and the second glass layer 303. The transparent projection medium 300 also includes a bonding layer 304. The P-polarized light reflecting layer 303 is directly formed on the surface of the second glass layer 303 (or directly formed on the surface of the outer glass) by, for example, vacuum coating, and then a bonding adhesive is applied on the first glass layer 301 and / or the P-polarized light reflecting layer 302 as the bonding layer 304 to bond the first glass layer 301 formed with the P-polarized light reflecting layer 302 to the second glass layer 303.

[0081] In some embodiments, such as Figure 5 As shown, the transparent projection medium 400 includes a first glass layer 401, a P-polarized light reflecting layer 402, and a second glass layer 403. The P-polarized light reflecting layer 402 is located between the first glass layer 401 and the second glass layer 403. The transparent projection medium 400 also includes a first bonding layer 404a, a second bonding layer 404b, and a substrate layer 405. The P-polarized light reflecting layer 402 is directly formed on the surface of the substrate layer 405 by, for example, vacuum coating, and the first bonding layer 404a is formed by applying bonding glue on the surface of the substrate layer 405 on which the P-polarized light reflecting layer 402 is formed and / or on the surface of the first glass layer 401, and the substrate layer 405 on which the P-polarized light reflecting layer 402 is formed is bonded to the first glass layer 401 by the first bonding layer 404a.

[0082] Similarly, a second bonding layer 404b is formed by applying bonding adhesive on the surface of the substrate layer 405 facing away from the P-polarized light reflecting layer 402 and / or on the surface of the second glass layer 403, and the substrate layer 405 and the second glass layer 403 are bonded together through the second bonding layer 404b. The substrate layer 405 is transparent.

[0083] Specifically, the substrate layer 405 is a transparent flexible substrate, such as polyethylene terephthalate (PET), polycarbonate (PC), thermoplastic polyurethane (TPU) and other polymer transparent substrates.

[0084] The thickness of the substrate layer 405 ranges from 25 μm to 1000 μm, preferably from 50 μm to 250 μm. If the substrate layer 405 is too thick, it will affect the optical performance of the transparent projection medium 400, while if the substrate layer 405 is too thin, it will not provide sufficient support.

[0085] In some embodiments, such as Figure 6 As shown, the transparent projection medium 500 includes a first glass layer 501, a P-polarized light reflecting layer 502, and a second glass layer 503. The P-polarized light reflecting layer 502 is located between the first glass layer 501 and the second glass layer 503. The transparent projection medium 500 also includes a first bonding layer 504a, a second bonding layer 504b, and a substrate layer 505. The P-polarized light reflecting layer 502 is directly formed on the surface of the substrate layer 505 by, for example, vacuum coating, and the first bonding layer 504a is formed by applying bonding glue on the surface of the substrate layer 505 on which the P-polarized light reflecting layer 502 is formed and / or on the surface of the second glass layer 503, and the substrate layer 505 on which the P-polarized light reflecting layer 502 is formed is bonded to the second glass layer 503 by the first bonding layer 504a.

[0086] Similarly, a second bonding layer 504b is formed by applying bonding adhesive on the surface of the substrate layer 505 that is away from the P-polarized light reflecting layer 502 and / or on the surface of the first glass layer 501, and the substrate layer 505 is bonded to the first glass layer 501 through the second bonding layer 504b. The material of the substrate layer 505 is a transparent flexible substrate, such as PET, PC, TPU. The thickness of the substrate layer 505 ranges from 25 μm to 1000 μm, preferably from 50 μm to 250 μm.

[0087] In other embodiments, the transparent projection medium 100 is not limited to the above Figures 3 to 6For example, the transparent projection medium 100 further includes a functional layer (not shown), which is stacked with the P polarized light reflection layer 102. The functional layer includes at least one of a transparent conductive layer, an ultraviolet protection layer and an explosion-proof layer. The conductive layer can be used as a heating element to generate heat energy after being energized to achieve the purpose of defogging and defrosting.

[0088] The following Figure 3 Based on the stacked structure of the transparent projection medium 200 shown, the structures of the P-polarized light reflecting layer 202 according to different embodiments are specifically described.

[0089] like Figure 7 As shown, in the transparent projection medium 200a, the P polarized light reflection layer 202a includes a metal layer 10 and a dielectric layer 20a which are stacked. The dielectric layer 20a includes a high refractive index layer 21 and a low refractive index layer 22 which are stacked, and the refractive index 22 of the low refractive index layer is less than the refractive index of the high refractive index layer 21. In this embodiment, the dielectric layer 20a includes two layers of high refractive index layers 21 and two layers of low refractive index layers 22. The two layers of high refractive index layers are respectively a first high refractive index layer 21a and a second high refractive index layer 21b. The two layers of low refractive index layers 22 are respectively a first low refractive index layer 22a and a second low refractive index layer 22b. The first high refractive index layer 21a, the first low refractive index layer 22a, the second high refractive index layer 21b and the second low refractive index layer 22b are stacked on the metal layer 10 in sequence.

[0090] The material of the metal layer 10 is selected from at least one of Ag, Au and Al. In this embodiment, the material of the metal layer 10 is Ag, and the thickness of the metal layer 10 ranges from 5 nm to 20 nm. Further, the thickness of the metal layer is greater than 6 nm, so as to reduce the optical absorption of the metal Ag. The thickness of the metal Ag layer is less than 15 nm, preferably less than 12 nm, so as to ensure that the reflectivity of P polarized light is met and achieve ultra-high transmittance.

[0091] The material of the high refractive index layer 21 is selected from oxides, alloy oxides, nitrides, or oxynitrides of at least one of the following elements: Zr, Nb, Si, Sn, Sb, Zn, In, Al, Ni, Cr, Mg, Mn, V, W, Hf, Ta, Mo, Ga, Y, Bi, and Ti.

[0092] The material of the low refractive index layer 22 is selected from oxides, alloy oxides, oxynitrides, carbides, or fluorides of at least one of the following elements: Zr, Si, Al, and Mg.

[0093] More specifically, in this embodiment, the material of the metal layer 10 is Ag, and the thickness of the metal layer 10 ranges from 7nm to 13nm. The material of the two high refractive index layers 21 is Nb2O5, and the refractive index of Nb2O5 ranges from 2.3 to 2.6. In this embodiment, the refractive index of Nb2O5 is 2.32. The material of the two low refractive index layers 22 is SiO2, and the refractive index of SiO2 is 1.46. The thickness of the first high refractive index layer 21a ranges from 30nm to 45nm. The thickness of the first low refractive index layer 22a ranges from 20nm to 35nm. The thickness of the second high refractive index layer 21b ranges from 7nm to 12nm. The thickness of the second low refractive index layer 22b ranges from 55nm to 66nm.

[0094] Figure 8 for Figure 7 The transparent projection medium 200a shown in FIG. 1 is a reflection spectrum diagram of P polarized light when the incident angle is 60°. Figure 8 As shown, the reflectivity of P polarized light is between 20% and 22% when the incident angle is 60° at a wavelength of 450nm to 650nm. The reflectivity range of the transparent projection medium 200a for P polarized light incident at an incident angle of 60° within the wavelength range of 450nm to 650nm is less than or equal to 3%.

[0095] Fig. 9 for Figure 7 The transparent projection medium 200a shown in FIG. 1 is a natural light transmission spectrum diagram when the incident angle is 0°. Fig. 9 As shown, the transmittance at an incident angle of 0° is in the range of 75% to 85% at a wavelength of 450 nm to 650 nm. In addition, the haze of the transparent projection medium 200a is less than 2%, or even less than 1%.

[0096] like Fig.10 As shown, in the P-polarized light reflecting layer 202b of the transparent projection medium 200b, the medium layer 20b includes a high refractive index layer 21 and a low refractive index layer 22. The low refractive index layer 22 and the high refractive index layer 21 are stacked on the metal layer 10 in sequence.

[0097] The P-polarized light reflecting layer 202b further includes a transition layer 30. Before the metal layer 10 is prepared, the transition layer 30 is directly formed on the surface of the first glass layer 201 to optimize the morphology and optical properties of the subsequent metal layer 10. The material of the transition layer 30 is selected from at least one of Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe, or the material of the transition layer is selected from the alloy, oxide, or nitride of at least one of the following elements: Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe.

[0098] The low refractive index layer 22 also serves as an isolation layer 40 to prevent the metal layer 10 from being oxidized and contaminated when the high refractive index layer 21 is subsequently prepared.

[0099] In this embodiment, the material of the metal layer 10 is Ag, and the thickness of the metal layer 10 is in the range of 7nm to 13nm. The high refractive index layer 21 is Nb2O5, and the refractive index is 2.32, and the thickness of the high refractive index layer 21 is in the range of 30nm to 45nm. The low refractive index layer 22 or the isolation layer 40 is Ti, and the thickness of the low refractive index layer 22 or the isolation layer 40 is in the range of 0.5nm to 5nm. The transition layer 30 is Cu, and the thickness of the transition layer 30 is in the range of 0.5nm to 5nm. Fig.11 for Fig.10 The transparent projection medium 200b shown in FIG. 1 is a reflection spectrum diagram of P polarized light when the incident angle is 60°. Fig.11 As shown, when the wavelength is between 450nm and 650nm and the incident angle is 60°, the reflectivity of the P polarized light is between 15% and 25%, more specifically, approximately between 17% and 20%. The reflectivity extreme difference of the transparent projection medium 200b for the P polarized light incident at an incident angle of 60° within the wavelength range of 450nm-650nm is less than or equal to 3%.

[0100] Fig.12 for Fig.10 The transparent projection medium 200b shown in FIG. 1 is a natural light transmission spectrum diagram when the incident angle is 0°. Fig.12 As shown, the transmittance at an incident angle of 0° is in the range of 72% to 80% at a wavelength of 450 nm to 650 nm. In addition, the haze of the transparent projection medium 200 b is less than 2%, or even less than 1%.

[0101] like Fig.13 As shown, in the P-polarized light reflecting layer 202c of the transparent projection medium 200c, the medium layer 20c includes three high refractive index layers 21 and three low refractive index layers 22. The three high refractive index layers 21 are respectively the first high refractive index layer 21a, the second high refractive index layer 21b and the third high refractive index layer 21c. The three low refractive index layers 22 are respectively the first low refractive index layer 22a, the second low refractive index layer 22b and the third low refractive index layer 22c. The first high refractive index layer 21a, the first low refractive index layer 22a, the second high refractive index layer 21b, the second low refractive index layer 22b, the third high refractive index layer 21c and the third low refractive index layer 22c are sequentially stacked on the metal layer 10.

[0102] The P-polarized light reflecting layer 202c further includes a transition layer 30, which is located on the side of the metal layer 10 away from the dielectric layer 20c. Before the metal layer 10 is prepared, the transition layer 30 is directly formed on the surface of the first glass layer 201 to optimize the morphology and optical properties of the subsequent metal layer 10. The material of the transition layer 30 is selected from at least one of Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe, or the material of the transition layer 30 is selected from the alloy, oxide or nitride of at least one of the following elements: Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe.

[0103] The P-polarized light reflecting layer 202c further includes an isolation layer 40. The isolation layer 40 is located between the metal layer 10 and the dielectric layer 20c to prevent the metal layer 10 from being oxidized and contaminated when preparing the high refractive index layer 21. The material of the isolation layer 40 is selected from at least one of Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe, or the material of the isolation layer 40 is selected from the alloy, oxide, or nitride of at least one of the following elements: Cr, Ni, Al, Ge, Ti, Cu, Au, Sn, Mo, Zn, Nb, Zr, V, and Fe.

[0104] In this embodiment, the material of the metal layer 10 is Ag, and the thickness of the metal layer ranges from 7nm to 13nm. The material of the high refractive index layer 21 is Nb2O5, and the refractive index is 2.32. The material of the low refractive index layer 22 is SiO2, and the refractive index is 1.46. The thickness of the first high refractive index layer ranges from 25nm to 28nm, the thickness of the first low refractive index layer ranges from 120nm to 130nm, the thickness of the second high refractive index layer ranges from 5nm to 13nm, the thickness of the second low refractive index layer ranges from 62nm to 70nm, the thickness of the third high refractive index layer ranges from 5nm to 28nm, and the thickness of the third low refractive index layer ranges from 12nm to 39nm. The transition layer 30 is Ge, and the thickness of the transition layer 30 ranges from 0.5nm to 5nm. The isolation layer 40 is Ti, and the thickness of the isolation layer 40 ranges from 0.5nm to 5nm.

[0105] Fig.14 for Fig.13 The transparent projection medium 200c shown in FIG. 1 is a reflection spectrum diagram of P polarized light when the incident angle is 60°. Fig.14 As shown, when the wavelength is between 450nm and 650nm and the incident angle is 60°, the reflectivity of the P polarized light is between 20% and 22%. The reflectivity difference of the transparent projection medium 200c for the P polarized light incident at an incident angle of 60° within the wavelength range of 450nm-650nm is less than or equal to 3%, or even less than or equal to 2%.

[0106] Fig.15 for Fig.13 The transparent projection medium 200c shown is a natural light transmission spectrum diagram when the incident angle is 0°. Fig. 9 As shown, between the wavelength of 450nm and 650nm, the transmittance at an incident angle of 0° is in the range of 82% to 85%. In addition, the haze of the transparent projection medium 200c is less than 2%. Through the above embodiments, it can be seen that Ge is used as a transition layer, and the optical effect is optimal. When the incident angle is 60 degrees, the reflectivity of P polarized light is ~20%, and the transmittance of natural light at 0 degrees is ~85%. This is because Ge makes the Ag layer more continuous, dense, and defect-free, reducing the optical loss caused by thin film scattering. But this is not absolute. The above optimal film system is only for the environment of this embodiment. For other equipment, processes, materials, substrates and other different coating environments, there are other more suitable film system structures. The embodiment of the present application only proposes that a low-absorption metal layer is combined with a dielectric layer, and its interference with light is comprehensively considered, so that a P polarized light reflection layer that is thinner and has fewer layers than a full dielectric layer can be obtained.

[0107] In summary, when the transparent projection medium of the embodiment of the present application is applied to the vehicle head-up display, the transparent projection medium is used as vehicle glass, and the haze is low, and the P polarized light reflectivity is 10% to 50% when the transmittance of the windshield is > 70%. In the embodiment of the present application, the optimal thickness range of the metal layer is 5nm to 20nm, and more preferably 8nm to 15nm. When the metal layer is an Ag reflective layer, the thickness of the Ag reflective layer is too thin, forming an island-like film, which seriously scatters and absorbs light; the thickness of the Ag reflective layer is too thick, which affects the transmittance of the windshield.

[0108] In the embodiment of the present application, the P polarized light reflecting layer is sandwiched between the first glass layer and the second glass layer, and the P polarized light reflecting layer is mainly composed of an ultra-thin metal layer (such as a silver layer) and a dielectric layer, thereby forming a transparent projection medium composed of the basic structure of the first glass layer, the metal layer, the dielectric layer and the second glass layer. In the embodiment of the present application, by comprehensively considering the effects of the glass layer, the metal layer and the dielectric layer on the light in the transparent projection medium, the effect of the metal layer on the incident light is combined with the interference effect of the dielectric layer and the glass, and the following beneficial effects can be achieved at the same time: the total number of layers of the P polarized light reflecting layer is less than 10 layers, the thickness is thin (in some embodiments, the total thickness of the P polarized light reflecting layer is <200nm), the haze of the transparent projection medium is less than 2%, the transmittance of the transparent projection medium to natural light is 70% to 90%, the reflectivity of the transparent projection medium to large-angle P polarized light is 15% to 25%, and the reflectivity range of the transparent projection medium to the P polarized light incident at an incident angle of 60° within the wavelength range of 450nm to 650nm is less than or equal to 3%, and the stability is good. Therefore, the transparent projection medium of the embodiment of the present application comprehensively considers the effects of the glass layer, the metal layer, and the dielectric layer on the light, and optimizes the microstructure of the metal layer to reduce the scattering and absorption loss of the metal layer to the light, and finally obtains a P-polarized light reflection layer with a small number of layers and a thin thickness, and has excellent optical effects. In addition, the P-polarized light reflection layer is sandwiched between the first glass layer and the second glass layer, is not exposed to the air, and has more stable performance.

[0109] The embodiment of the present application also provides a vehicle (not shown). The vehicle includes the above-mentioned projection system 1000. The vehicle is a vehicle in a broad sense, such as a road vehicle (such as a commercial vehicle, a passenger car, a motorcycle, a train, etc.), a water vehicle (such as a ship), an air vehicle (such as an airplane), an industrial vehicle (such as a forklift, a trailer, a tractor, etc.), an agricultural equipment (such as a lawn mower, a harvester, etc.), or an entertainment device (such as a toy vehicle).

[0110] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A transparent projection medium, characterized in that: include: First glass layer; Second glass layer; as well as A P-polarized light reflecting layer is located between the first glass layer and the second glass layer; the P-polarized light reflecting layer includes a stacked metal layer and a dielectric layer; the dielectric layer includes a stacked high-refractive index layer and a low-refractive index layer, and the refractive index of the low-refractive index layer is less than the refractive index of the high-refractive index layer.

2. The transparent projection medium according to claim 1, characterized in that: The metal layer is a nano silver layer, and its thickness ranges from 5nm to 20nm.

3. The transparent projection medium according to claim 2, characterized in that: The dielectric layer comprises a high refractive index layer and a low refractive index layer, the low refractive index layer and the high refractive index layer are sequentially stacked on the nanosilver layer, the high refractive index layer has a thickness of 30nm to 45nm, and the low refractive index layer has a thickness in the range of 0.5nm to 5nm; Or, the medium layer includes two layers of the high refractive index layer and two layers of the low refractive index layer, the two layers of the high refractive index layer are defined as the first high refractive index layer and the second high refractive index layer, the two layers of the low refractive index layer are defined as the first low refractive index layer and the second low refractive index layer, the first high refractive index layer, the first low refractive index layer, the second high refractive index layer and the second low refractive index layer are sequentially stacked on the nanosilver layer, the thickness of the first high refractive index layer is in the range of 30nm to 45nm, the thickness of the first low refractive index layer is in the range of 20nm to 35nm, the thickness of the second high refractive index layer is in the range of 7nm to 12nm, and the thickness of the second low refractive index layer is in the range of 55nm to 66nm; Or, the medium layer includes three layers of high refractive index layers and three layers of low refractive index layers, and the three layers of high refractive index layers are defined as a first high refractive index layer, a second high refractive index layer and a third high refractive index layer, and the three layers of low refractive index layers are defined as a first low refractive index layer, a second low refractive index layer and a third low refractive index layer, and the first high refractive index layer, the first low refractive index layer, the second high refractive index layer, the second low refractive index layer, the third high refractive index layer and the third low refractive index layer are sequentially stacked on the nanosilver layer, the thickness of the first high refractive index layer ranges from 25nm to 28nm, the thickness of the first low refractive index layer ranges from 120nm to 130nm, the thickness of the second high refractive index layer ranges from 5nm to 13nm, the thickness of the second low refractive index layer ranges from 62nm to 70nm, the thickness of the third high refractive index layer ranges from 5nm to 28nm, and the thickness of the third low refractive index layer ranges from 12nm to 39nm.

4. The transparent projection medium according to claim 2, characterized in that: The P-polarized light reflection layer further comprises a transition layer, the transition layer is located on a side of the nano-silver layer away from the dielectric layer, and the transition layer is used to improve the morphology of the nano-silver layer; and / or, The P-polarized light reflection layer further comprises an isolation layer, which is located between the nano-silver layer and the dielectric layer. The isolation layer is used to prevent the nano-silver layer from being oxidized when the dielectric layer is prepared.

5. The transparent projection medium according to claim 4, characterized in that: When the P-polarized light reflection layer further includes the transition layer, the thickness of the transition layer is in the range of 0.5 nm to 5 nm; When the P-polarized light reflecting layer further includes the isolation layer, the thickness of the isolation layer is in the range of 0.5 nm to 5 nm.

6. The transparent projection medium according to any one of claims 1 to 5, characterized in that: The total number of P-polarized light reflecting layers is less than 10; and / or, The total thickness of the P-polarized light reflecting layer is less than 200 nm; and / or, The haze of the transparent projection medium is less than 2%; and / or, The reflectivity of the transparent projection medium to P-polarized light is 15% to 25%; and / or, The reflectivity extreme difference of the transparent projection medium for P-polarized light incident at an incident angle of 60° within a wavelength range of 450nm-650nm is less than or equal to 3%; and / or, The transmittance of the transparent projection medium to natural light is 70% to 90%.

7. The transparent projection medium according to any one of claims 1 to 5, characterized in that: The transparent projection medium further comprises a bonding layer, wherein the P-polarized light reflection layer is formed on the surface of the first glass layer and is bonded to the second glass layer through the bonding layer; or, The transparent projection medium further comprises a bonding layer, wherein the P-polarized light reflecting layer is formed on the surface of the second glass layer and is bonded to the first glass layer through the bonding layer; or, The transparent projection medium also includes a first bonding layer, a second bonding layer and a substrate layer. The P-polarized light reflecting layer is formed on the surface of the substrate layer and is bonded to the first glass layer through the first bonding layer. The side of the substrate layer facing away from the P-polarized light reflecting layer is bonded to the second glass layer through the second bonding layer.

8. The transparent projection medium according to any one of claims 1 to 5, characterized in that: The transparent projection medium further comprises a functional layer, the functional layer is stacked with the P-polarized light reflecting layer, and the functional layer comprises at least one of a conductive layer, an anti-ultraviolet layer and an explosion-proof layer.

9. A projection system, characterized in that: include: A projection light source, used for emitting projection light including P-polarized light; as well as The transparent projection medium according to any one of claims 1 to 8, configured to receive and reflect the projection light.

10. A means of transport, characterized in that: Comprising the projection system as claimed in claim 9.

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