Projection display device and vehicle

Abstract

This application provides a projection display device and a vehicle, wherein the opposing sides of the projection display device are designated as the first side and the second side, respectively, and the projection display device includes an inner light-transmitting layer, a display layer, and an outer light-transmitting layer, which are sequentially stacked in the direction from the first side to the second side, wherein the display layer is configured to display a projected image received from a projection light source, the inner light-transmitting layer is configured to allow the projected image displayed on the display layer to be displayed toward the first side, and the outer light-transmitting layer is configured to restrict the projected image displayed on the display layer from being displayed toward the second side. The projection display device according to this application can perform a privacy protection function by displaying the projected image toward one of the opposing sides and not basically displaying the projected image toward the other side.

Description

[Technical Field]

[0001] This application relates to the art of glass, and more particularly to projection display devices and vehicles. [Background technology]

[0002] As people's reliance on vehicles increases, so do the needs for vehicles. One of these needs is the desire to use more space or flat surfaces as carriers for information media, and in particular, the desire to project images directly onto the vehicle's glass using projection light sources. [Overview of the project] [Problems that the invention aims to solve]

[0003] A Chinese patent application with publication number CN113415051A discloses a glass and product having a display function, comprising a laminated inner layer glass, a display unit layer, and an outer layer glass, wherein the outer layer glass is used to quantitatively control the transmittance of natural light, thereby suppressing interference from sunlight to the image displayed on the display unit layer when ambient light is strong, and improving image contrast. [Means for solving the problem]

[0004] This application provides a projection display device and a vehicle, which can perform a privacy protection function by displaying a projected image toward one of the two opposing sides of the projection display device and not displaying the projected image toward the other side.

[0005] According to a first aspect, the present application provides a projection display device comprising an inner light-transmitting layer, a display layer, and an outer light-transmitting layer, which are arranged in order in a direction from the first side to the second side, with the opposing sides designated as a first side and a second side, wherein the display layer is configured to display a projected image received from a projection light source, the inner light-transmitting layer is configured to allow the projected image displayed on the display layer to be displayed toward the first side, and the outer light-transmitting layer is configured to restrict the projected image displayed on the display layer from being displayed toward the second side.

[0006] If necessary, the light rays projected by the projection light source are polarized, the inner light-transmitting layer is configured to transmit polarized light reflected by the display layer, and / or the outer light-transmitting layer is configured to absorb polarized light that has passed through the display layer.

[0007] If necessary, the inner light-transmitting layer includes a first light-transmitting plate having an incident surface toward the projection light source and a transmittance of 90% or more with respect to the polarized light.

[0008] If necessary, the projected image displayed on the display layer has a first brightness, and the projected image reflected by the incident surface of the first light-transmitting plate has a second brightness, with the ratio of the first brightness to the second brightness being 4.5 or greater.

[0009] If necessary, the polarization is P-polarized, and the P-polarized is at an incident angle θ i It is projected onto the incident surface, θ i is equation θ i =tan -1 (n g / n i ) satisfies, however n g The refractive index of the first light-transmitting plate is n i This is the refractive index of air.

[0010] If necessary, the inner light-transmitting layer further includes a second light-transmitting plate provided between the first light-transmitting plate and the display layer.

[0011] If necessary, the outer light-transmitting layer includes a polarizing layer having a light-transmitting axis, the light-transmitting axis being perpendicular to the polarization direction of the polarized light projected onto the polarizing layer.

[0012] If necessary, the outer light-transmitting layer further includes a third light-transmitting plate having a transmittance of 50% or less to natural light, with the polarizing layer provided between it and the display layer.

[0013] If necessary, the outer light-transmitting layer further includes a third light-transmitting plate provided between the display layer and the polarizing layer.

[0014] If necessary, the brightness of the projected image transmitted through the polarization layer is a third brightness, and this third brightness is 5 nits or less.

[0015] According to a second aspect, the present application further provides a vehicle comprising a window which is at least in part a projection display device as described in an embodiment of the first aspect, and a projection light source for providing a projected image toward the inner light-transmitting layer of the projection display device. [Effects of the Invention]

[0016] The projection display device according to this application can perform a privacy protection function by displaying the projected image only towards one of the two opposing sides, and not displaying the projected image towards the other side.

[0017] To more clearly illustrate the examples of this specification or the technical solutions in the prior art, the following drawings, which are necessary for describing the examples or the prior art, are briefly introduced below. Clearly, the drawings described below are only a few examples of those described herein, and those skilled in the art can obtain other drawings based on these drawings without expedient effort. [Brief explanation of the drawing]

[0018] [Figure 1] Schematic diagram of a projection display device according to the first embodiment of this application. [Figure 2] Schematic diagram of a projection display device according to the second embodiment of this application. [Figure 3] Schematic diagram of the display module in FIG. 2 [Figure 4] Schematic diagram of the projection display device according to the third embodiment of the present application [Figure 5] Schematic diagram of the projection display device according to the fourth embodiment of the present application

Mode for Carrying Out the Invention

[0019] In order for those skilled in the art to better understand the technical solutions in the present application, hereinafter, referring to the drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts should belong to the scope of protection of the present application.

[0020] As used herein, the term "comprising" and its variations mean open inclusion, that is, "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one exemplary embodiment" and "one embodiment" mean "at least one exemplary embodiment". The term "another embodiment" means "at least one another embodiment". The terms "first", "second", etc. may refer to different or the same objects, and it cannot be understood that they indicate or imply relative importance or implicitly indicate the number of the indicated components. The terms "inside" and "outside" are only for distinguishing different objects and cannot be understood as limitations with respect to a specific direction. Unless otherwise stated, "multi-layer" means two or more layers.

[0021] The inventors of this application have discovered that in the prior art, images displayed on glass with a display function are shown to both sides of the glass, resulting in privacy breaches. For example, when such glass is used as a car window, if a person inside the car projects an image onto the glass using a projection light source, the projected image will be visible not only to the person inside the car but also to people outside. This is undesirable for the person inside the car.

[0022] To solve the above problems, an embodiment of the first aspect of this application provides a projection display device that has a privacy protection function and is applicable to showcases, architectural window curtain walls, automobile glass, ship glass, locomotive glass, human-computer interaction, electrical equipment, information kiosks, etc.

[0023] The projection display device has two opposing sides, designated as the first side and the second side, and includes an inner light-transmitting layer, a display layer, and an outer light-transmitting layer, which are stacked sequentially from the first side to the second side. The display layer is configured to display a projected image received from a projection light source. The inner light-transmitting layer is configured to allow the projected image displayed on the display layer to be displayed toward the first side. The outer light-transmitting layer is configured to restrict the projected image displayed on the display layer from being displayed toward the second side; in other words, the outer light-transmitting layer is configured to prevent or obstruct the projected image displayed on the display layer from being displayed toward the second side, thereby preventing the projected image displayed on the display layer from being seen or viewed by a person located on the second side, and thus fulfilling a privacy protection function.

[0024] If necessary, the inner translucent layer may be a single layer or a multilayer structure. The outer translucent layer may also be a single layer or a multilayer structure.

[0025] For example, the projection display device may be projection display glass. The inner light-transmitting layer may be single-layer or multi-layer glass. The outer light-transmitting layer may be single-layer or multi-layer glass.

[0026] In some embodiments, the light ray projected by the projection light source is polarized, and the polarization may be linearly polarized, circularly polarized, or of a higher order. In some embodiments, the light ray projected by the projection light source is P-polarized, and P-polarized is a type of linearly polarized light. In this embodiment, the beneficial effect of employing P-polarized light is that when P-polarized light is incident at a specific angle, the reflectivity becomes almost zero, thereby significantly reducing reflection of the light ray from the glass surface and thus reducing the occurrence of image ghosting.

[0027] In this embodiment, the inner light-transmitting layer is configured to transmit polarized light reflected by the display layer so as to allow the projected image displayed on the display layer to be displayed toward the first side, and / or the outer light-transmitting layer is configured to absorb polarized light transmitted through the display layer so as to restrict the projected image displayed on the display layer to be displayed toward the second side.

[0028] The principle of this application will be described in detail below with reference to exemplary embodiments and drawings.

[0029] Figure 1 is a schematic diagram of a projection display device 100 according to the first embodiment of this application.

[0030] As shown in Figure 1, the projection display device 100 has two opposing sides, a first side 101 and a second side 102, respectively. The projection display device 100 includes an inner light-transmitting layer 10, a display layer 20, and an outer light-transmitting layer 30, which are stacked sequentially in the direction from the first side 101 to the second side 102, with the display layer 20 located between the inner light-transmitting layer 10 and the outer light-transmitting layer 30. The projection light source projects light rays toward the inner light-transmitting layer 10. In this embodiment, the light rays projected by the projection light source (not shown) are polarized L1.

[0031] In this embodiment, as shown in FIG. 1, the inner light-transmitting layer 10 includes a first light-transmitting plate 11 having an incident surface 111 facing the projection light source. The polarized light L1 projected from the projection light source is incident on the incident surface 111 of the first light-transmitting plate 11, and at least a part of the polarized light L1 passes through the first light-transmitting plate 11 to form a first transmitted light L2. The first transmitted light L2 is projected onto the display layer 20, and the display layer 20 can reflect a part of the first transmitted light L2 to form a first reflected light L3 (i.e., the projection image). By allowing the first light-transmitting plate 11 to transmit the first reflected light L3, it is allowed to display the projection image toward the first side 101.

[0032] In this embodiment, as shown in FIG. 1, the outer light-transmitting layer 30 includes a polarizing layer 31. A part of the first transmitted light L2 passes through the display layer 20 to form a second transmitted light L4. The second transmitted light L4 is projected onto the polarizing layer 31. Since the polarizing layer 31 has a light-transmitting axis orthogonal to the polarization direction of the second transmitted light L4, almost all or most of the second transmitted light L4 is absorbed by the polarizing layer 31 and cannot pass through the polarizing layer 31, thereby restricting the display of the projection image toward the second side 102. The dashed arrows in FIG. 1 indicate the polarization directions of the respective light rays.

[0033] In this embodiment, as shown in FIG. 1, the ratio of the luminance of the projection image displayed on the display layer 20 to the luminance of the projection image reflected by the incident surface 111 of the first light-transmitting plate 11 is 4.5 or more. For example, the ratio is 10 or more, or 100 or more. Therefore, even if a small amount of polarized light is reflected by the incident surface 111 to form a second reflected light L5, the luminance of the formed projection image is much lower than the luminance of the projection image displayed on the display layer 20, thereby avoiding the occurrence of image ghosting on the incident surface 111 of the first light-transmitting plate 11.

[0034] Exemplarily, the polarized light L1 projected from the projection light source is P-polarized light. As shown in FIG. 1, the P-polarized light is projected onto the incident surface 111 of the first light-transmitting plate 11 at an incident angle θ i and θ i satisfies the formula θ i =tan -1 (n g / n i ) and θ iThis is also called Brewster's angle, where n g n is the refractive index of the first light-transmitting plate 11, and n i This is the refractive index of air. Theoretically, P-polarized light is incident at angle θ. i When projected onto the incident surface 111 of the first light-transmitting plate 11, the reflectivity of the incident surface 111 for P-polarized light is 0. Therefore, reflection of P-polarized light by the first light-transmitting plate 11 is effectively suppressed, and the brightness of the projected image reflected by the incident surface 111 of the first light-transmitting plate 11 is significantly reduced, thereby effectively preventing image ghosting from occurring on the incident surface 111.

[0035] In this embodiment, the projected image transmitted through the polarizing layer 31 has a brightness of 5 nits or less, for example, a brightness of 2 nits or less, for example, a brightness of 1 nit or less. Therefore, even if a small amount of second transmitted light L4 passes through the polarizing layer 31 to form third transmitted light L6, the presented projected image becomes difficult to see or perceive by a person on the second side 102 of the projection display device 100, thereby still preventing the leakage of privacy.

[0036] In this embodiment, the first light-transmitting plate 11 may, if necessary, have a transmittance of 60% or more with respect to the polarization L1, for example, 90% or more, and may be 95% or 98%. The high transmittance of the first light-transmitting plate 11 with respect to the polarization L1 can improve the brightness of the projected image displayed on the display layer 20. For example, the first light-transmitting plate 11 may be single-pane glass or double-pane glass, and the double-pane glass may have a hollow intervening layer.

[0037] For example, the polarizing layer 31 may be a flexible transparent substrate. For instance, the polarizing layer 31 may be a linear polarizing filter, specifically a thin film polarizer, a filter or thin film layer having a linear dichroic material such as an anisotropic polymer layer, deformed metal nanoparticles, a nanoparticle linear thin film polarizer, a metal polarizer, and the like.

[0038] Here, the thin-film polarizer may have an optical multilayer structure, and nanoscale or micronscale molecules can be provided in the multilayer structure. By controlling the rotational direction and thickness of the molecules, the wavelength and polarization response of the thin-film polarizer can be controlled.

[0039] Here, the core film material that performs the polarizing effect in the dichroic thin film layer is a polyvinyl alcohol (PVA) thin film, whose components are mainly light atoms such as carbon, hydrogen, and oxygen, and which has characteristics such as high light transmittance and high ductility. After the PVA film is dyed in a dyeing bath, bidirectional molecules, metal salts such as gold, silver, and iron, or dye molecules and polyethylene molecules are uniformly concentrated on its surface. After the PVA film is stretched by applying an external force, the molecular chains of the PVA film are distributed along the direction of the external force, and at this time, the bidirectional molecules are also regularly distributed, thereby forming a polarizing layer 31 with uniform bidirectional absorption performance and a light transmittance axis perpendicular to the direction of stretching. The nanoparticle linear thin film polarizer is made by embedding elongated ellipsoidal nanoparticles in sodium silicate glass.

[0040] In this embodiment, the polarization layer 31 may, if necessary, be a combination of one or more types of linear polarization filters and phase delay devices, and the phase delay device may be a quarter-wavelength delay device and / or a half-wavelength delay device.

[0041] In this embodiment, as shown in Figure 1, the first light-transmitting plate 11 and the display layer 20 may be connected via the first adhesive layer 40, and the polarizing layer 31 and the display layer 20 may be connected via the second adhesive layer 50.

[0042] If necessary, the first light-transmitting plate 11, the first adhesive layer 40, the display layer 20, and the second adhesive layer 50 may be configured so as not to change the polarization state of the polarized light L1 projected from the projection light source. That is, the polarized light L1, the first transmitted light L2, the first reflected light L3, and the second transmitted light L4 have the same polarization state, for example, all of which are P-polarized. This eliminates the need to particularly consider changes in the polarization state, and makes it easy to position the light-transmitting axis of the polarizing layer 31 according to the polarization state of the polarized light L1.

[0043] However, this application is not limited thereto, and one or more of the first light-transmitting plate 11, the first adhesive layer 40, the display layer 20, and the second adhesive layer 50 may be configured to change the polarization state of the polarized light L1, that is, the polarization states of the polarized light L1, the first transmitted light L2, the first reflected light L3, and the second transmitted light L4 may be partially or completely different, in which case it is necessary to position the light-transmitting axis of the polarized layer 31 according to the polarization state of the second transmitted light L4 projected onto the polarized layer 31.

[0044] In one feasible technical solution, the first adhesive layer 40 and the second adhesive layer 50 are made from a transparent adhesive material, which may be polyvinyl butyral (PVB), polycarbonate, soundproof PVB, ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), ionomer, thermoplastic material and any combination thereof, or transparent optical adhesive (OCA), liquid transparent optical adhesive (LOCA) or optically transparent resin (OCR).

[0045] If necessary, the transmittance of the first adhesive layer 40 and / or the second adhesive layer 50 to the polarization L1 is 85% or more, and may be, for example, 90% or more or 95% or more.

[0046] If necessary, the first adhesive layer 40 has a haze of 1% or less, for example, 0.4% or less.

[0047] If necessary, the first adhesive layer 40 has a thickness of 0.1 mm to 1 mm, for example, 0.38 mm or 0.76 mm, and the second adhesive layer 50 has a thickness of 0.1 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0048] In another feasible technical solution, the second adhesive layer 50 differs from the above technical solution in that it is made from a dark-colored adhesive material, specifically a gray PVB film, a light gray PVB film, a blue PVB film, a light blue PVB film, or a green PVB film. ,also This may be one or any combination of brown PVB films.

[0049] If necessary, the transmittance of the second adhesive layer 50 to the polarized light L1 is 50% or less, for example, 5% or less, or 2% or less.

[0050] In this embodiment, the display layer 20 may have a display function in whole or in part. The display layer 20 may be one or more combinations of light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), liquid crystal displays (LCDs), projection display films, and electroluminescence. Here, LEDs, LCDs, and OLEDs achieve the display effect by using an external electric field to cause the internal light-emitting material to emit light. Projection displays achieve the display effect by utilizing the principle that projection display films have a high reflectivity to projector light rays. Electroluminescence causes electrons to collide with the light-emitting center using an electric field, generating an energy level transition and ultimately emitting light. These display technologies have a fast response speed, low energy consumption, and a wide viewing angle.

[0051] If necessary, the display layer 20 may be smaller than or equal to the size of the first light-transmitting plate 11, and the polarizing layer 31 may be smaller than or equal to the size of the first light-transmitting plate 11.

[0052] Figure 2 is a schematic diagram of a projection display device 100 according to a second embodiment of the present application, and differs from the first embodiment of the present application in that the inner light-transmitting layer 10 further includes a second light-transmitting plate 12 provided between the first light-transmitting plate 11 and the display layer 20, and it can be understood that the first light-transmitting plate 11, the second light-transmitting plate 12, the display layer 20 and the polarizing layer 31 are sequentially stacked in the direction from the first side 101 to the second side 102.

[0053] If necessary, the second light-transmitting plate 12 may have a transmittance of 90% or more with respect to the polarization L1, for example, 90%, 95%, or 98%, and the high transmittance of the second light-transmitting plate 12 with respect to the polarization L1 can improve the brightness of the projected image displayed on the display layer 20. For example, the second light-transmitting plate 12 may be a transparent substrate, and its material may be a transparent material such as polyethylene terephthalate (PET), triacetylcellulose film (TAC), or polymethyl methacrylate (PMMA).

[0054] In this embodiment, as shown in Figure 2, the second light-transmitting plate 12 is connected to the display layer 20 via a third adhesive layer 60. The third adhesive layer 60 is made from a transparent adhesive material, and may be polyvinyl butyral (PVB), polycarbonate, soundproof PVB, ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), ionomer, thermoplastic material, or a combination thereof, or it may be a transparent optical adhesive (OCA), liquid transparent optical adhesive (LOCA), or optically transparent resin (OCR).

[0055] If necessary, the transmittance of the third adhesive layer 60 to the polarized light L1 may be 85% or more, for example, 90% or 95%.

[0056] If necessary, the third adhesive layer 60 may have a thickness of 0.1 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0057] If necessary, the display layer 20 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the second light-transmitting plate 12, and the polarizing layer 31 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the second light-transmitting plate 12.

[0058] In this embodiment, as shown in Figure 3, the display module is composed of a second light-transmitting plate 12, a third adhesive layer 60, a display layer 20, a second adhesive layer 50, and a polarizing layer 31. The second light-transmitting plate 12 and the polarizing layer 31 act as protective layers for the display layer 20, allowing the display module to be manufactured, installed, and removed as a single integrated component. For example, after the display layer 20 is damaged, only the display module can be replaced, reducing the late-stage maintenance costs of the projection display device.

[0059] Figure 4 is a schematic diagram of a projection display device 100 according to a third embodiment of this application, and differs from the first embodiment of this application in that the outer light-transmitting layer 30 further includes a third light-transmitting plate 32 with a polarizing layer 31 between it and the display layer 20, and it can be understood that the first light-transmitting plate 11, the display layer 20, the polarizing layer 31 and the third light-transmitting plate 32 are sequentially stacked in the direction from the first side 101 to the second side 102.

[0060] If necessary, the third light-transmitting plate 32 may have a transmittance of 50% or less to natural light, for example, 40%, 30%, 20%, or 10%, thereby reducing the transmittance to natural light and suppressing interference of the image displayed on the display layer 20 by external light. For example, the third light-transmitting plate 32 may be single-pane glass or double-pane glass, and the double-pane glass may have a hollow intervening layer.

[0061] In this embodiment, as shown in Figure 4, the third translucent plate 32 is connected to the display layer 20 via the fourth adhesive layer 70. The fourth adhesive layer 70 is made from a dark-colored adhesive material, specifically, a gray PVB film or EVA, a light gray PVB film or EVA, a blue PVB film or EVA, a light blue PVB film or EVA, a green PVB film or EVA. ,tea A colored PVB film or EVA may also be used.

[0062] If necessary, the transmittance of the fourth adhesive layer 70 to polarization L1 is 50% or less, for example, 5% or less, or 2% or less.

[0063] If necessary, the fourth adhesive layer 70 may have a thickness of 0.1 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0064] If necessary, the display layer 20 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the third light-transmitting plate 32, and the polarizing layer 31 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the third light-transmitting plate 32.

[0065] In this embodiment, when manufacturing the projection display device 100, the polarizing layer 31 and the display layer 20 are pre-combined via the second adhesive layer 50 to form a composite assembly, and then the composite assembly is combined with the first light-transmitting plate 11 and the third light-transmitting plate 32 by hot pressing to obtain the projection display device 100.

[0066] Figure 5 is a schematic diagram of a projection display device 100 according to the fourth embodiment of this application, which differs from the third embodiment in that the third light-transmitting plate 32 is provided between the display layer 20 and the polarizing layer 31, and can be understood to be provided in a sequential stacking manner in the direction from the first side 101 to the second side 102.

[0067] In this embodiment, the third light-transmitting plate 32 has a transmittance of 98% or less with respect to the polarization L1, and for example, a transmittance of 50% or less, for example, 30% or less, for example, 10% or less.

[0068] In this embodiment, as shown in Figure 5, the third light-transmitting plate 32 is connected to the display layer 20 via the fourth adhesive layer 70. The material, light transmittance, and thickness of the fourth adhesive layer 70 can be set by referring to the third embodiment of this application, so a detailed explanation is omitted.

[0069] If necessary, the display layer 20 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the third light-transmitting plate 32, and the polarizing layer 31 may be no larger than or equal to the size of the first light-transmitting plate 11 and / or the third light-transmitting plate 32.

[0070] An embodiment of a second aspect of this application provides a vehicle including a car window and a projection light source for providing a projected image. The car window is at least in part a projection display device 100 according to an embodiment of a first aspect of this application. The inner light-transmitting layer 10 of the projection display device 100 faces inward as the inner glass of the car window, or faces outward as the outer glass of the car window.

[0071] In some embodiments, the projection light source may include a light-emitting diode (LED), a liquid crystal display (LCD), a digital light processing (DLP) projection light source, or any other image projection light source. The projection light source may be a fixed light source, for example, fixed to the sheet metal of the vehicle interior, or a mobile light source, for example, a mobile phone. The projection light source may be an interior light source or an exterior light source.

[0072] In some embodiments, the inner light-transmitting layer 10 of the projection display device 100 faces inward, and the projection light source is installed inside the vehicle so as to project the projection image toward the inner light-transmitting layer 10. As a result, the projected image is visible to people inside the vehicle but is barely visible to people outside the vehicle.

[0073] In other embodiments, the inner light-transmitting layer 10 of the projection display device 100 faces outwards from the vehicle, and the projection light source is positioned outside the vehicle so as to project the image toward the inner light-transmitting layer 10. As a result, the projected image is visible to people outside the vehicle but is barely visible to people inside the vehicle.

[0074] The above specific examples have provided a further detailed explanation of the purpose, technical solutions, and beneficial effects of this application. However, these are merely specific examples of this application and are not intended to limit the scope of protection provided by this application. It should be understood that any amendments, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should all be included within the scope of protection provided by this application.

Claims

1. A projection display device, The opposing sides are designated as the first side and the second side, and the structure includes an inner translucent layer, a display layer, and an outer translucent layer, which are sequentially laminated in the direction from the first side to the second side. The display layer is configured to display a projected image received from a projection light source. The inner light-transmitting layer is configured to allow the projected image displayed on the display layer to be displayed facing the first side. The outer light-transmitting layer is configured to restrict the projection image displayed on the display layer from being displayed toward the second side. Projection display device.

2. The light rays projected by the aforementioned projection light source are polarized, The inner light-transmitting layer is configured to transmit polarized light reflected by the display layer, and / or the outer light-transmitting layer is configured to absorb polarized light that has passed through the display layer. The projection display device according to claim 1.

3. The inner light-transmitting layer includes a first light-transmitting plate having an incident surface toward the projection light source and a transmittance of 90% or more with respect to the polarized light. The projection display device according to claim 2.

4. The projected image displayed on the display layer has a first brightness, the projected image reflected by the incident surface of the first light-transmitting plate has a second brightness, and the ratio of the first brightness to the second brightness is 4.5 or greater. The projection display device according to claim 3.

5. The aforementioned polarization is P-polarization, and the P-polarization is at an incident angle θ ｉ It is projected onto the incident surface, θ ｉ The following equation is satisfied, θ ｉ =tan －１ (n ｇ / n ｉ ) However, n ｇ The refractive index of the first light-transmitting plate is n ｉ This is the refractive index of air. The projection display device according to claim 3.

6. The inner light-transmitting layer further includes a second light-transmitting plate provided between the first light-transmitting plate and the display layer. The projection display device according to claim 3.

7. The outer light-transmitting layer includes a polarizing layer having a light-transmitting axis, wherein the light-transmitting axis is perpendicular to the polarization direction of the polarized light projected onto the polarizing layer. The projection display device according to any one of claims 2 to 6.

8. The outer light-transmitting layer further includes a third light-transmitting plate having a transmittance of 50% or less to natural light, with the polarizing layer provided between it and the display layer. The projection display device according to claim 7.

9. The outer light-transmitting layer further includes a third light-transmitting plate provided between the display layer and the polarizing layer. The projection display device according to claim 7.

10. The brightness of the projected image transmitted through the polarization layer is the third brightness, and the third brightness is 5 nits or less. The projection display device according to claim 7.

11. A car window which is at least part a projection display device according to any one of claims 1 to 10, A projection light source for providing a projected image toward the inner light-transmitting layer of the projection display device, including, vehicle.

Images