Transparent display device

Abstract

The invention provides a transparent display device. The transparent display device comprises a screen body and a second polarizer. The screen body comprises a substrate, a light-emitting unit and a first polarizer, the light-emitting unit is located on one side of the substrate, and the first polarizer is located on the light-emitting side of the light-emitting unit. The second polarizer is located on the side, away from the light-emitting unit, of the substrate, and the polarization direction of the second polarizer intersects with the polarization direction of the first polarizer. When polarized light emitted from the first polarizer is reflected at the interface of the screen body and the outside and is emitted to the second polarizer, the second polarizer can block part of light rays with different polarization directions from the second polarizer to pass through, so that the transmission amount of reflected light can be reduced, and the problem of back side light leakage is solved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a transparent display device. Background Art

[0002] A transparent display device is one that provides a transparent display state, allowing the user to view the scene behind it. It is commonly found in display windows, vending machines, and other applications. A transparent display device has a display area and a transparent area. The display area provides a display image for the user to view, while the transparent area is transparent, allowing the user to see the scene behind it. Pixels are arranged in the display area to emit image beams toward the display surface (or light-emitting side) of the transparent display device, thereby providing the image.

[0003] However, part of the image light beam will be reflected back into the transparent display device at the interface between the display surface and the outside world, and then pass through the back side of the transparent display device, causing the backside light leakage problem. Summary of the Invention

[0004] The purpose of this application is to provide a transparent display device, aiming to reduce the problem of backside light leakage.

[0005] An embodiment of the present application provides a transparent display device, comprising: a screen body, comprising a substrate, a light-emitting unit and a first polarizer, wherein the light-emitting unit is located on one side of the substrate, and the first polarizer is located on the light-emitting side of the light-emitting unit; a second polarizer is located on a side of the substrate away from the light-emitting unit, and the polarization direction of the second polarizer intersects with the polarization direction of the first polarizer.

[0006] In some embodiments, a boundary of an orthographic projection of the screen on the second polarizer is greater than or equal to 0.1 mm away from an edge of the second polarizer.

[0007] In some embodiments, the second polarizer comprises a polarizing film or a polarization grating.

[0008] In some embodiments, the first polarizer includes mutually parallel metal gratings, and the parallel direction of the plurality of metal gratings is perpendicular to the polarization direction of the first polarizer.

[0009] In some embodiments, the screen body further includes an encapsulation layer, which is located on a side of the first polarizer facing away from the substrate and covers a surface of the substrate.

[0010] In some embodiments, the invention further includes: a first cover plate located on a side of the encapsulation layer facing away from the substrate; a second cover plate located on a side of the substrate facing away from the encapsulation layer, and the second cover plate is located between the substrate and the second polarizer.

[0011] In some embodiments, it also includes: an optical structure, located between the first cover plate and the second cover plate, and arranged around the edge of the screen body; wherein, the optical structure includes an absorption film, an adhesive layer and a hue film, the absorption film is located on the surface of the first cover plate, the hue film is located on the surface of the second cover plate, and the adhesive layer is located between the absorption film and the hue film.

[0012] In some embodiments, the light-emitting unit includes a light-emitting diode, which includes an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer, and the light-emitting layer is located between the N-type semiconductor layer and the P-type semiconductor layer; wherein the first polarizer is located on the side of the N-type semiconductor layer away from the light-emitting layer.

[0013] In some embodiments, the screen includes a display area and a non-display area, and the light-emitting units are arranged in an array in the display area; the screen also includes a shading layer located on the substrate, and the shading layer is located between adjacent light-emitting units and is arranged on the same layer as the light-emitting units.

[0014] In some embodiments, the substrate includes: a transparent base; a driving circuit layer located between the transparent base and the light-emitting unit; wherein the driving circuit layer includes a driving circuit connected to the light-emitting unit, and the driving circuit is only located in the display area.

[0015] In the transparent display device provided in the embodiments of the present application, a first polarizer is disposed on the light-emitting side of the light-emitting unit, and a second polarizer is disposed on the side of the substrate facing away from the light-emitting unit, with the polarization direction of the second polarizer intersecting that of the first polarizer. When polarized light emitted from the first polarizer is reflected at the interface between the screen and the outside world and strikes the second polarizer, the second polarizer blocks the passage of light with a different polarization direction, thereby reducing the amount of reflected light transmitted and thereby alleviating backside light leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0017] Figure 1 is a schematic cross-sectional structural diagram of a transparent display device provided in some embodiments of the present application;

[0018] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of the middle screen;

[0019] Figure 3 yes Figure 2 A schematic cross-sectional structure diagram of the light-emitting unit and the first polarizer;

[0020] Figure 4 yes Figure 3 A schematic diagram of a top view of the first polarizer;

[0021] Figure 5 is a schematic cross-sectional structural diagram of a transparent display device provided in some embodiments of the present application;

[0022] Figure 6 yes Figure 5 Simulation test chart of the reflectivity of the middle and outer screen areas;

[0023] Figure 7 It is a schematic flow chart of a method for preparing a metal grating provided in some embodiments of the present application.

[0024] Description of reference numerals:

[0025] 100 / 200, transparent display device; X, first direction; Y, second direction; Z, third direction;

[0026] 10. Screen body; 101. Display area; 102. Non-display area;

[0027] 11. substrate; 111. transparent base; 112. driving circuit layer;

[0028] 12. Light-emitting unit; 120. Light-emitting side; 121. N-type semiconductor layer; 122. Light-emitting layer; 123. P-type semiconductor layer; 124. P-type electrode; 125. N-type electrode; 126. Diffusion layer; 127. Distributed Bragg reflector;

[0029] 13. First polarizer; 131. Metal grating; A1. Outgoing light; A2. Reflected light;

[0030] 14. Encapsulation layer; 15. Light shielding layer;

[0031] 20. a second polarizer;

[0032] 30. First cover plate;

[0033] 40. Second cover plate;

[0034] 50. Optical structure; 51. Absorption film; 52. Adhesive layer; 53. Hue film;

[0035] 60. Anti-reflection film. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only 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 are within the scope of protection of this application.

[0037] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0038] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0040] When in display mode, a transparent display device can display images in the display area and appear transparent in the transparent area. When in off mode, the entire device appears transparent. A transparent display device has a front and a back. The front side can display images and is also called the light-emitting surface or light-emitting side.

[0041] Since light emitted from the front is easily reflected at the junction of the screen and the outside world, and the transparent display device has a high transmittance, the high transmittance will cause the reflected light to be transmitted to the back, resulting in a large light leakage at the back, causing others to be able to view the reflected image from the back, making the transparent display screen insufficient in protecting privacy.

[0042] Based on this, an embodiment of the present application provides a transparent display device, comprising a screen and a second polarizer. The screen comprises a substrate, a light-emitting unit, and a first polarizer. The light-emitting unit is located on one side of the substrate, and the first polarizer is located on the light-emitting side of the light-emitting unit. The second polarizer is located on the side of the substrate facing away from the light-emitting unit, and the polarization direction of the second polarizer intersects with the polarization direction of the first polarizer.

[0043] In the transparent display device provided in the embodiments of the present application, a first polarizer is disposed on the light-emitting side of the light-emitting unit, and a second polarizer is disposed on the side of the substrate facing away from the light-emitting unit, with the polarization direction of the second polarizer intersecting that of the first polarizer. When polarized light emitted from the first polarizer is reflected at the interface between the screen and the outside world and strikes the second polarizer, the second polarizer blocks the passage of light with a different polarization direction, thereby reducing the amount of reflected light transmitted and thereby alleviating backside light leakage.

[0044] The structure of the transparent display device provided in the embodiment of the present application is described below with reference to the accompanying drawings. In this embodiment, a Cartesian coordinate system (X, Y, and Z) is used to represent the orientation of the diagram, where the third direction Z is the thickness direction of the transparent display device, and the first direction X and the second direction Y are perpendicular to the third direction.

[0045] See also Figure 1 and Figure 2 , Figure 1 is a schematic cross-sectional view of a transparent display device provided in some embodiments of the present application. Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of the middle screen.

[0046] The transparent display device 100 includes a screen 10 and a second polarizer 20. The screen 10 includes a substrate 11, a light-emitting unit 12, and a first polarizer 13. The light-emitting unit 12 is located on one side of the substrate 11, and the first polarizer 13 is located on the light-emitting side 120 of the light-emitting unit 12. The second polarizer 20 is located on the side of the substrate 11 away from the light-emitting unit 12, and the polarization direction of the second polarizer 20 intersects with the polarization direction of the first polarizer 13.

[0047] For example, the first polarizer has a first polarization direction, the second polarizer has a second polarization direction, and the angle between the first polarization direction and the second polarization direction is greater than 0 and less than or equal to 90°.

[0048] like Figure 1 As shown, the outgoing light A1 from the first polarizer 13 has a first polarization direction. The outgoing light A1 is reflected at the interface between the screen 10 and the external environment, and the reflected light A2 still has the first polarization direction. When the reflected light A2 reaches the second polarizer 20, because the second polarization direction of the second polarizer 20 intersects with the first polarization direction, the second polarizer 20 can block a portion of the reflected light A2 from passing through the second polarizer 20. In other words, it blocks a portion of the reflected light A2 from passing through the back side of the transparent display device 100, thereby reducing backside light leakage and protecting user privacy.

[0049] In some embodiments, the second polarization direction of the second polarizer 20 is perpendicular to the first polarization direction, that is, the angle between them is 90°, which can completely block the reflected light A2 in the first polarization direction from passing through from the back, thereby improving the privacy protection effect.

[0050] In some embodiments, the second polarizer 20 may include a polarization film or a polarization grating. It should be noted that any structure capable of generating polarized light in the second polarization direction falls within the protection scope of the present application.

[0051] The boundary of the orthographic projection of the screen 10 on the second polarizer 20 is greater than or equal to 0.1 mm from the edge of the second polarizer 20. In other words, the screen 10 can roughly overlap with the second polarizer 20, so that the reflected light from the back of the screen 10 can basically reach the second polarizer 20.

[0052] In some embodiments, the orthographic projection of the screen 10 on the second polarizer 20 is within the range of the second polarizer 20. In this way, all reflected light from the back of the screen 10 can reach the second polarizer 20, so that the second polarizer 20 can block all reflected light from the back of the screen 10 to a certain extent. Figure 1 For the single screen structure of the embodiment, the screen 10 and the second polarizer 20 completely overlap to improve the effect of preventing back light leakage.

[0053] Figure 1The transparent display device 100 has a single-screen structure. The screen 10 may include a substrate 11, a light-emitting unit 12, a first polarizer 13, and an encapsulation layer 14. The encapsulation layer 14 is located on the side of the first polarizer 13 facing away from the substrate 11 and covers the surface of the substrate 11. The outgoing light A1 is reflected on the outer surface of the encapsulation layer 14 to form reflected light A2. The screen 10 is protected by the encapsulation layer 14. The first polarizer 13 is provided on the light-emitting side 120 of the light-emitting unit 12, and the second polarizer 20 is attached to the back of the screen 10, thereby achieving the back-side light leakage prevention effect of the single-screen structure.

[0054] like Figure 2 As shown, the light-emitting unit 12 can be a light-emitting diode (LED) or a micro-light-emitting diode (Micro-LED). The light-emitting unit 12 can include a red LED, a blue LED, and a green LED. The first polarizer 13 is located on the upper surface of the light-emitting unit 12 (i.e., the light-emitting side 120).

[0055] The screen 10 may include a display area 101 and a non-display area 102 (i.e., a transparent area) adjacent to the display area 101. The light-emitting units 12 are arranged in an array in the display area 101. When the screen 10 is in the off state, the display area 101 also appears transparent.

[0056] In some embodiments, the display area 101 and the non-display area 102 can be alternately arranged in the first direction X, or the position of the display area 101 can be set according to the specific position of the image to be displayed. The size of the display area 101 and the non-display area 102 can be set according to actual display needs.

[0057] The screen 10 may further include a light-shielding layer 15 on the substrate 11. The light-shielding layer 15 is located between adjacent light-emitting units 12 and is disposed on the same layer as the light-emitting units 12. The encapsulation layer 14 covers the surface of the first polarizer 13, the sidewalls of the light-emitting units 12, the surface of the light-shielding layer 15, and the surface of the substrate 11 in the non-display area 102. The light-shielding layer 15 can reduce the reflection of external light on the substrate 11, thereby improving the transparent display effect.

[0058] In some embodiments, the light shielding layer 15 may be a black light-absorbing material for absorbing light from the external environment that enters the screen body 10 .

[0059] The substrate 11 in the screen body 10 may include a transparent substrate 111 and a driving circuit layer 112. The driving circuit layer 112 is located between the transparent substrate 111 and the light-emitting unit 12, between the transparent substrate 111 and the light-shielding layer 15, and between the transparent substrate 111 and the encapsulation layer 14. The driving circuit layer 112 includes a driving circuit (including a thin film transistor) connected to the light-emitting unit 12. The driving circuit is only located in the display area 101 and not in the non-display area 102, thereby enhancing the transparency of the non-display area 102. Other organic and / or inorganic transparent film layers in the driving circuit layer 112 can extend from the display area 101 to the non-display area 102, that is, the non-display area 102 is a stacked structure of transparent organic and / or inorganic film layers.

[0060] Specifically, the driving circuit layer 112 may include a buffer layer, an active layer, a first gate insulating layer, a first gate electrode, a second gate insulating layer, a second gate electrode, an interlayer dielectric layer, a source electrode, and a drain electrode. The buffer layer is located on the transparent substrate 111, the active layer is located on the buffer layer, the first gate insulating layer is located on the buffer layer and covers the active layer. The first gate electrode is located on the first gate insulating layer, the second gate insulating layer is located on the first gate insulating layer and covers the first gate electrode. The second gate electrode is located on the second gate insulating layer, and the interlayer dielectric layer is located on the second gate insulating layer and covers the second gate electrode. The source electrode and the drain electrode are located on the interlayer dielectric layer and are connected to both sides of the active layer through vias, respectively.

[0061] See also Figure 3 and Figure 4 , Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure of the light-emitting unit and the first polarizer, Figure 4 yes Figure 3 Schematic diagram of the top view of the first polarizer.

[0062] The first polarizer 13 may include mutually parallel metal gratings 131, and the parallel directions of the plurality of metal gratings 131 are perpendicular to the polarization direction of the first polarizer. For example, the plurality of metal gratings 131 extend along the second direction Y, that is, are arranged in parallel along the second direction Y. When unpolarized light is incident on the metal grating 131, the electric field component of the light can be decomposed into two components, one parallel to the metal grating 131 and the other perpendicular to the metal grating 131. The electric field component parallel to the metal grating 131 will induce a current in the metal grating 131. Due to the conductivity of the metal, this component will be reflected or absorbed and thus blocked. The electric field component perpendicular to the metal grating 131 can continue to propagate through the gaps between the metal gratings 131 and is therefore transmitted, that is, it can generate polarized light in the first direction X perpendicular to the second direction Y, so that the first polarizer 13 has a first polarization direction.

[0063] In some embodiments, the spacing between adjacent metal gratings 131 (which can be seen as thin lines) can be smaller than the wavelength of the incident light (i.e., the output light of the light-emitting diode) to ensure that the electric field component of the light can be effectively processed. By precisely designing the line width and spacing, the polarization efficiency and light transmittance can be optimized. The metal grating 131 can be aluminum, silver or other conductive materials. The process of manufacturing the metal grating 131 includes photolithography, nanoimprinting and other precision machining processes to ensure the precise arrangement and size of the fine lines.

[0064] like Figure 3 As shown, the light-emitting unit 12 includes a light-emitting diode, which includes an N-type semiconductor layer 121, a light-emitting layer 122, and a P-type semiconductor layer 123. The light-emitting layer 122 is located between the N-type semiconductor layer 121 and the P-type semiconductor layer 123. The first polarizer 13 is located on a side of the N-type semiconductor layer 121 away from the light-emitting layer 122.

[0065] The material of the light emitting layer 122 may include alternating indium gallium nitride (InGaN) layers and gallium nitride (GaN) layers, the P-type semiconductor layer 123 may include gallium nitride (p-GaN) and magnesium (Mg), and the N-type semiconductor layer 121 may include gallium nitride (n-GaN) and silicon (Si) / oxygen (O).

[0066] The light-emitting diode further includes a P-type electrode 124 and an N-type electrode 125. The two ends of the P-type electrode 124 are connected to the P-type semiconductor layer 123 and the driving circuit, respectively. The two ends of the N-type electrode 125 are connected to the N-type semiconductor layer 121 and the driving circuit, respectively. The P-type electrode 124 and the N-type electrode 125 are located on the same side of the N-type semiconductor layer 121 facing away from the first polarizer 13 to prevent interference between the P-type electrode 124 and the N-type electrode 125 and the first polarizer 13.

[0067] The light-emitting diode may further include a diffusion layer 126 located between the P-type semiconductor layer 123 and the P-type electrode 124, for spreading current to improve conductivity between the P-type semiconductor layer 123 and the P-type electrode 124. The material of the diffusion layer 126 may be at least one of indium tin oxide, indium gallium oxide, indium tin zinc oxide, and a conductive polymer.

[0068] The LED may also include a distributed Bragg reflector (DBR) 127, which is located on the side of the diffusion layer 126 facing away from the P-type semiconductor layer 123 to reflect more light back to the light-emitting side 120, thereby increasing the amount of light emitted from the device. The P-type electrode 124 extends through the distributed Bragg reflector 127.

[0069] The distributed Bragg reflector 127 can be composed of multiple layers of alternating high and low refractive index materials, such as aluminum nitride (AlN) and gallium nitride (GaN). The thickness of each layer is typically one-quarter of the target reflection wavelength (quarter-wavelength thickness). This periodic structure leads to the Bragg reflection effect, which causes light of a specific wavelength to be strongly reflected between layers. When light reflects on interfaces with different refractive indices, part of the light is reflected and part of the light is transmitted. By precisely designing the thickness and refractive index of each layer, the distributed Bragg reflector 127 can achieve high reflectivity at specific wavelengths. This reflection is due to the interference effect caused by the phase difference between adjacent layers, which is called Bragg reflection.

[0070] See also Figure 5 , Figure 5 is a schematic cross-sectional view of a transparent display device provided by some embodiments of the present application. Figure 1 The difference between the embodiments is that the transparent display device 200 is an integrated screen. For an integrated screen, due to the thick module thickness, when light leaks from the back, the user can see two double images on the front and back.

[0071] The transparent display device 200 includes not only a screen 10 and a second polarizer 20, but also a first cover plate 30 and a second cover plate 40. The structure of the screen 10 can be referred to Figure 2 .

[0072] The first cover plate 30 is located on the side of the encapsulation layer 14 facing away from the substrate 11. The second cover plate 40 is located on the side of the substrate 11 facing away from the encapsulation layer 14, and the second cover plate 40 is located between the substrate 11 and the second polarizer 20. The addition of the first cover plate 30 and the second cover plate 40 to the integrated screen improves the strength of the transparent display device 200 and provides support and protection for the screen body 10.

[0073] Among them, the outgoing light A1 from the first polarizer 13 is mainly reflected on the outer surface of the first cover plate 30. When the reflected light A2 reaches the second cover plate 40 and the second polarizer 20, the second polarization direction of the second polarizer 20 and the first polarization direction of the reflected light A2 intersect with each other, resulting in part of the reflected light A2 being unable to be emitted. Therefore, it can reduce back light leakage, thereby protecting privacy and solving the ghosting problem.

[0074] The orthographic projection of the screen 10 on the second polarizer 20 may be within the range of the second polarizer 20. For example, the area of ​​the second polarizer 20 may be greater than or equal to the area of ​​the screen 10, and the second polarizer 20 may cover the entire back surface of the second cover 40.

[0075] In order to increase the transmittance of the area outside the screen body 10 to improve the transparency effect, the second polarizer 20 may be only arranged to completely overlap with the screen body 10 without extending to the area outside the screen body 10 .

[0076] The transparent display device 200 may further include an optical structure 50, which is located between the first cover plate 30 and the second cover plate 40 and is arranged around the edge of the screen body 10, that is, located in an area outside the screen body. Therefore, the optical structure 50 can protect the edge of the screen body 10 and prevent damage.

[0077] In which, the optical structure 50 includes an absorption film 51, an adhesive layer 52 and a hue film 53, the absorption film 51 is located on the surface of the first cover plate 30 (that is, the side of the first cover plate 30 facing the second cover plate 40), the hue film 53 is located on the surface of the second cover plate 40 (that is, the side of the second cover plate 40 facing the first cover plate 30), and the adhesive layer 52 is located between the absorption film 51 and the hue film 53, for combining the absorption film 51 and the hue film 53.

[0078] The absorption film 51 can be used to absorb light incident from the external environment, so that the absorption rate of the area outside the screen body 10 is consistent with that of the screen body 10 area, so that the transmittance and reflectivity of the area outside the screen body 10 match those of the screen body 10 area. The material of the absorption film 51 can include organic dyes, metal oxides, or nanomaterials. Among them, since the light absorption of the screen body 10 area mainly depends on the light shielding layer 15, in order to ensure that the absorption rate of the screen body 10 area and the absorption rate of the area outside the screen body 10 are consistent, the material of the absorption film 51 can be the same as that of the light shielding layer 15, such as a black organic dye.

[0079] The hue film 53 can include multiple layers with different refractive indices. The thickness and refractive index of these films are precisely designed to utilize the interference effect of light. When light passes through these films, light of different wavelengths interferes constructively or destructively, thereby changing the color of the transmitted light and matching the color of the screen 10. The hue film 53 can adjust the three RGB spectral bands of the transparent display device to achieve a consistent color effect. For example, the material of the hue film 53 may include alternating layers of silicon oxide / silicon nitride, silicon oxide / niobium oxide, or silicon nitride / magnesium fluoride, each with a large refractive index difference.

[0080] Therefore, through the setting of the absorption film 51 and the hue film 53, when the screen body 10 is in the off state, there is no obvious visual difference between the screen body 10 area and the non-screen body 10 area (that is, the area outside the screen body 10), so that the transparent display device 200 looks like a whole, that is, an integrated screen is realized.

[0081] See also Figure 6 , Figure 6 yes Figure 5 Simulation test diagram of the reflectivity of the middle screen area and the outer screen area.

[0082] The reflectivity of light within the wavelength range of 360nm to 660nm is tested. Due to the setting of the optical structure 50 in the area outside the screen, the reflectivity of the screen area tends to be consistent with the reflectivity of the area outside the screen, thereby achieving the effect of an integrated screen.

[0083] The transparent display device 200 may further include an anti-reflection film 60 . The anti-reflection film 60 is located on a side of the first cover plate 30 facing away from the second cover plate 40 , and is used to reduce reflection of ambient light to improve the transparency effect.

[0084] See also Figure 7 , Figure 7 : is a schematic flow chart of a method for preparing a metal grating provided in some embodiments of the present application. The method for preparing the metal grating includes:

[0085] Step S1: providing a light-emitting unit, wherein the light-emitting unit includes a light-emitting diode, and the light-emitting diode includes an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer, wherein the light-emitting layer is located between the N-type semiconductor layer and the P-type semiconductor layer;

[0086] Step S2: forming a metal film layer on a side of the N-type semiconductor layer away from the light-emitting layer;

[0087] Step S3: performing an etching process or a nanoimprinting process on the metal film layer to form metal gratings parallel to each other along the second direction.

[0088] Through the above preparation method, metal gratings parallel to each other along the second direction can be formed on the light-emitting side of the light-emitting diode. The metal gratings parallel to each other along the second direction can generate polarized light in the first direction X perpendicular to the second direction Y, so that the first polarizer has a first polarization direction.

[0089] The description of the above embodiments is only used to help understand the technical solutions and core ideas of this application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A transparent display device, characterized in that: include: A screen body, comprising a substrate, a light-emitting unit and a first polarizer, wherein the light-emitting unit is located on one side of the substrate, and the first polarizer is located on the light-emitting side of the light-emitting unit; The second polarizer is located on a side of the substrate away from the light-emitting unit, and the polarization direction of the second polarizer crosses the polarization direction of the first polarizer.

2. The transparent display device according to claim 1, wherein: The boundary of the orthographic projection of the screen body on the second polarizer is greater than or equal to 0.1 mm away from the edge of the second polarizer.

3. The transparent display device according to claim 1 or 2, characterized in that: The second polarizer includes a polarization film or a polarization grating.

4. The transparent display device according to claim 1, wherein: The first polarizer includes mutually parallel metal gratings, and the parallel direction of the plurality of metal gratings is perpendicular to the polarization direction of the first polarizer.

5. The transparent display device according to claim 1, wherein: The screen body further includes an encapsulation layer, which is located on a side of the first polarizer facing away from the substrate and covers a surface of the substrate.

6. The transparent display device according to claim 5, wherein: Also includes: a first cover plate, located on a side of the encapsulation layer facing away from the substrate; The second cover plate is located on a side of the substrate facing away from the encapsulation layer, and the second cover plate is located between the substrate and the second polarizer.

7. The transparent display device according to claim 6, wherein: Also includes: an optical structure, located between the first cover plate and the second cover plate and arranged around the edge of the screen body; The optical structure includes an absorption film, an adhesive layer and a hue film. The absorption film is located on the surface of the first cover plate, the hue film is located on the surface of the second cover plate, and the adhesive layer is located between the absorption film and the hue film.

8. The transparent display device according to claim 1, wherein: The light emitting unit includes a light emitting diode, which includes an N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer, wherein the light emitting layer is located between the N-type semiconductor layer and the P-type semiconductor layer; Wherein, the first polarizer is located on a side of the N-type semiconductor layer away from the light-emitting layer.

9. The transparent display device according to claim 1, wherein: The screen body includes a display area and a non-display area, and the light-emitting units are arranged in an array in the display area; The screen body further includes a light shielding layer located on the substrate. The light shielding layer is located between adjacent light emitting units and is provided on the same layer as the light emitting units.

10. The transparent display device according to claim 9, wherein: The substrate comprises: transparent substrate; a driving circuit layer, located between the transparent substrate and the light-emitting unit; The driving circuit layer includes a driving circuit connected to the light-emitting unit, and the driving circuit is only located in the display area.

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