Display device

Abstract

The invention provides a display device. The display device comprises a substrate, a driving device layer, a light emitting device and a lens assembly. The driving device layer is arranged on the substrate, the light-emitting device comprises a bonding metal layer, a light-emitting layer and a transparent conductive layer, the bonding metal layer is arranged on the driving device layer, the light-emitting layer is arranged on the bonding metal layer, and the transparent conductive layer is arranged on the light-emitting layer. The lens assembly comprises an inner-layer lens and an outer-layer lens, the inner-layer lens is arranged on the corresponding light-emitting device, the inner-layer lens is made of silicon nitride, the outer-layer lens is made of silicon dioxide, the outer-layer lens is arranged on the periphery of the inner-layer lens, and the refractive index of the inner-layer lens is larger than that of the outer-layer lens. According to the display device, through the double-layer lens structure, the light extraction efficiency is improved under the condition that the total height of the lens is not increased.

Description

Technical Field

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

[0002] In augmented reality (AR) display technology, Micro LED display devices usually use micro lens arrays to improve the light extraction efficiency of the display device, such as Figure 1 As shown, the existing Micro LED display device includes a light-emitting device and a microlens 104. The light-emitting device includes a bonding metal layer 101, a light-emitting layer 102 and a transparent conductive layer 103. The microlens 104 is arranged on the light-emitting device. The microlens 104 is used to make the light distribution more concentrated in the vertical direction, thereby improving the light extraction efficiency. This is because the collimating optical system of the AR product can only accept light within ±15 degrees, and the higher the parallelism of the light, the higher the efficiency of the collimating optical system. However, to obtain a higher degree of parallelism, a larger ratio of the height H of the microlens 104 to the diameter CD (H / CD>1.5) is required, such as Figure 2 For example, when the pixel pitch is 4 microns, the height of the microlens 104 needs to be greater than 6 microns. This requires a thicker silicon dioxide coating, but an overly thick silicon dioxide coating is prone to peeling and other problems, affecting the product yield. Summary of the invention

[0003] An object of the embodiments of the present application is to provide a display device to improve light extraction efficiency without increasing the total height of the lens.

[0004] An embodiment of the present application provides a display device, comprising: a substrate; a driving device layer, the driving device layer being arranged on the substrate; a light-emitting device, the light-emitting device comprising a bonding metal layer, a light-emitting layer and a transparent conductive layer, the bonding metal layer being arranged on the driving device layer, the light-emitting layer being arranged on the bonding metal layer, and the transparent conductive layer being arranged on the light-emitting layer; and a lens assembly, the lens assembly comprising an inner lens and an outer lens, the inner lens being arranged on the corresponding light-emitting device, the outer lens being arranged at the periphery of the inner lens, and the refractive index of the inner lens being greater than the refractive index of the outer lens.

[0005] In the above display device, at least a portion of the inner lens is sleeved in the outer lens, the diameter of the outer lens is larger than the diameter of the inner lens, and the height of the inner lens is larger than the height of the outer lens.

[0006] In the above display device, the surfaces of the inner lens and the outer lens are both convex arc surfaces, and the curvature of the surface of the inner lens ranges from 80 to 130; the curvature of the surface of the outer lens ranges from 60 to 90.

[0007] In the above display device, the material of the inner lens is silicon nitride, and the material of the outer lens is silicon dioxide.

[0008] In the above display device, the difference in refractive index between the materials of the inner lens and the outer lens is greater than or equal to 0.25 and less than or equal to 0.4.

[0009] In the above display device, the refractive index of the inner lens ranges from 1.7 to 1.9; the refractive index of the outer lens ranges from 1.45 to 1.50.

[0010] In the above display device, the height of the inner lens is greater than 1.1 times the height of the outer lens and less than 1.5 times the height of the outer lens.

[0011] In the above display device, the diameter of the outer lens is greater than 1.1 times the diameter of the inner lens and less than 1.5 times the diameter of the inner lens.

[0012] In the above display device, the ratio of the height to the diameter of the inner lens ranges from 0.75 to 1.0; and the ratio of the height to the diameter of the outer lens ranges from 0.4 to 0.6.

[0013] In the above display device, the axes of the inner lens and the outer lens coincide with each other.

[0014] In the above display device, the intensity half angle range of the lens assembly is 25 degrees to 30 degrees.

[0015] The display device provided by the present application realizes effective collimation of light through the cooperation of inner and outer double-layer lenses. Specifically, the inner lens is made of silicon nitride, and the outer lens is made of silicon dioxide. The difference in refractive index of the two materials (silicon nitride refractive index 1.75-1.85, silicon dioxide refractive index 1.45-1.50) forms two refractive interfaces on the light propagation path. When the light is emitted from the light emitting layer, it first undergoes the first refraction of the inner lens. Since the inner lens has a higher refractive index, it can refract the light diverging at a large angle into a small angle light, and then undergo the second refraction of the outer lens to further collimate the small angle light, and finally make the divergent light more parallel. Since the height of the inner lens is greater than the height of the outer lens, and at least a part of the inner lens is set in the outer lens, a good light collimation effect can be achieved by two refractions without increasing the total height of the lens, that is, the light extraction efficiency is improved. This avoids the problem of having to increase the thickness of the silicon dioxide coating in order to obtain the same light extraction efficiency in the traditional single-layer lens structure, thereby causing the film to peel off. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a schematic diagram of a first technical solution of a lens arranged on a light-emitting device in an existing display device.

[0017] Figure 2 It is a schematic diagram of a second technical solution of a lens arranged on a light-emitting device in an existing display device.

[0018] Figure 3 is a schematic diagram of a display device provided in an embodiment of the present application.

[0019] Figure 4 It is a schematic diagram of a lens disposed on a light-emitting device in a display device provided in an embodiment of the present application.

[0020] Figure 5 It is a schematic diagram comparing the light effects of the preferred technical solution of the present application and two existing technical solutions. DETAILED DESCRIPTION

[0021] The specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0022] The terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different technical features. The term "plurality" and similar words mean two or more, unless otherwise clearly defined.

[0023] The embodiments of the present application may be combined with each other.

[0024] like Figure 3 As shown, the display device provided in the embodiment of the present application may be, for example, a Micro-LED display device. The display device includes a display panel, a source driving circuit, a gate driving circuit, a timing controller, a light controller, and a power management chip. The display panel includes a substrate, a data line DATA, a scan line SCAN, a power line (VDD, VSS), a light control signal line EM, a pixel array, etc.

[0025] The substrate may be, for example, a glass substrate, a flexible substrate (e.g., a polyimide substrate), etc. The pixel array is composed of a plurality of pixel units PX arranged in rows and columns, and each pixel unit PX includes a light-emitting device and a pixel driving circuit. The pixel driving circuit is electrically connected to the light-emitting device, and the pixel driving circuit is used to control the brightness of each light-emitting device of the display device. Each level of gate driving unit in the gate driving circuit controls a row of pixel units PX. The source driving circuit is used to provide a data signal to the pixel unit PX. The timing controller is used to receive external image data and synchronization signals, and generate signals required by the gate driving circuit and the source driving circuit. The power management chip is used to provide the required operating voltage for each part of the display device.

[0026] In addition, the display device provided in the embodiment of the present application may also be integrated with an embedded touch circuit, and the touch circuit is used to implement a touch function.

[0027] like Figure 4 As shown, the display device provided by the embodiment of the present application includes a substrate, a driving device layer, a light-emitting device and a lens assembly. The driving device layer is arranged on the substrate. The light-emitting device includes a bonding metal layer 401, a light-emitting layer 402 and a transparent conductive layer 403, wherein the bonding metal layer 401 is arranged on the driving device layer, the light-emitting layer 402 is arranged on the bonding metal layer 401, and the transparent conductive layer 403 is arranged on the light-emitting layer 402. The lens assembly includes an inner lens 405 and an outer lens 404, The inner lens 405 is disposed on the corresponding light emitting device, and the outer lens 404 is disposed (sheathed) on the periphery of the inner lens 405 . The refractive index of the inner lens 405 is greater than that of the outer lens 404 .

[0028] At least a portion of the inner lens 405 is sleeved in the outer lens 404 . The diameter of the outer lens 404 is larger than the diameter of the inner lens 405 . The height of the inner lens 405 is larger than the height of the outer lens 404 .

[0029] The distance between two adjacent light emitting devices is 4 microns.

[0030] The lens assembly is used to convert the divergent beam into a collimated beam within the range of ±15 degrees.

[0031] In a specific embodiment, the substrate may be a silicon substrate, and the driver device layer includes a driver transistor array. The bonding metal layer 401 in the light-emitting device is made of a gold-tin alloy material; the light-emitting layer 402 is a Micro-LED chip, including an active region and a quantum well structure; and the transparent conductive layer 403 is indium tin oxide (ITO). The inner lens 405 and the outer lens 404 in the lens assembly both extend in a direction perpendicular to the substrate and away from the driver device layer, and the central axes of the two coincide.

[0032] The angle between the sidewall of the light emitting layer 402 and the normal line of the substrate can be controlled within a range of 75 degrees to 90 degrees.

[0033] The transparent conductive layer 403 covers the top surface and side surfaces of the light emitting layer 402 .

[0034] The surfaces of the inner lens 405 and the outer lens 404 are both convex arc surfaces, that is, the surfaces of the inner lens 405 and the outer lens 404 are both spherical cap shapes.

[0035] The spherical cap-shaped outer surfaces of the inner lens 405 and the outer lens 404 can be formed by photolithography. The spherical cap shape is conducive to controlling the emission direction of light, making it easier for the light to converge within a predetermined field of view angle range.

[0036] The transition area between the two lenses is an arc surface, and the width of the transition area is in the range of 0.1 micron to 0.3 micron.

[0037] The curvature of the surface of the inner lens 405 ranges from 80° to 130°; the curvature of the surface of the outer lens 404 ranges from 60° to 90°.

[0038] The curvature range (80 to 130) of the inner lens 405 is greater than the curvature range (60 to 90) of the outer lens 404, so that the light can obtain a stronger first refraction when passing through the inner lens 405, and can be further collimated when passing through the outer lens 404. The inner lens 405 with a larger curvature can provide a stronger refractive power, while the outer lens 404 with a smaller curvature can adjust the light that has undergone the first refraction and reduce the deflection angle of the light.

[0039] The material of the inner lens 405 is silicon nitride, and the material of the outer lens 404 is silicon dioxide.

[0040] The refractive index difference between the materials of the inner lens 405 and the outer lens 404 is greater than or equal to 0.25 and less than or equal to 0.4. The refractive index difference of 0.25 to 0.4 ensures that light can be sufficiently refracted at the interfaces of the two lenses without causing excessive interface reflection losses due to excessive refractive index difference.

[0041] The refractive index of the inner lens 405 ranges from 1.7 to 1.9. Preferably, the refractive index of the inner lens 405 ranges from 1.75 to 1.85. The refractive index of the outer lens 404 ranges from 1.45 to 1.50.

[0042] The refractive index of the silicon nitride material used in the inner lens 405 can be adjusted within the range of 1.7 to 1.9 by adjusting the deposition process parameters (such as gas ratio, temperature, pressure, etc.). When the refractive index is controlled within the range of 1.75 to 1.85, the best light extraction efficiency can be obtained. The refractive index of the silicon dioxide material used in the outer lens 404 can be adjusted within the range of 1.45 to 1.50 by plasma enhanced chemical vapor deposition (PECVD) process. The refractive index in this range ensures both good optical performance and the compactness and stability of the film.

[0043] The height of the inner lens 405 is greater than 1.1 times the height of the outer lens 404 and less than 1.5 times the height of the outer lens 404 .

[0044] This height ratio relationship enables the light to obtain a stronger first refraction when passing through the inner lens 405, and then obtain a second refraction at the outer lens 404, while avoiding the problem of silicon dioxide coating peeling caused by the excessive total height.

[0045] The height of the inner lens 405 ranges from 0.012 mm to 0.018 mm, and the height of the outer lens 404 ranges from 0.010 mm to 0.015 mm. Within this height range, the stress of the lens can be effectively controlled to avoid cracking or peeling.

[0046] As an improvement, the side wall of the inner lens 405 includes multiple first steps, the transition area of ​​the first step is set to be chamfered, and the chamfer angle is 30 degrees to 45 degrees, and the inner wall of the outer lens 404 is provided with a second step matching the step. The contact interface of the two layers of lenses is stepped.

[0047] The diameter of the outer lens 404 is greater than 1.1 times the diameter of the inner lens 405 and less than 1.5 times the diameter of the inner lens 405 .

[0048] The ratio between the diameter of the outer lens 404 and the diameter of the inner lens 405 ensures that the light is fully refracted by the inner lens 405 while also reserving a sufficient edge area for the outer lens 404 to collect divergent light at a large angle.

[0049] As an improvement, the bottom edge area of ​​the outer lens 404 is provided with an annular reinforcing rib, the height of which is 10% to 20% of the total height of the lens. A locking portion is provided at the junction of the inner and outer lenses 404, and the locking angle of the locking portion is 60 degrees to 75 degrees.

[0050] The cross-section of the reinforcing rib is trapezoidal, and the width of the upper base of the trapezoid is smaller than the width of the lower base, forming a support surface inclined outward. A locking structure including a protrusion and a recessed portion is provided at the junction of the bottom of the inner and outer lenses 404. The cross-section of the protrusion is dovetail-shaped, and the cross-section of the recessed portion matches the protrusion. The locking structure is evenly distributed along the circumference of the lens to form an annular locking structure. The outer surface of the outer lens 404 is provided with an anti-reflective periodically arranged micro-prism array, and the ridge direction of the micro-prism is arranged radially. A positioning reference surface is provided at the bottom of the inner lens 405, and the reference surface is in close contact with the top surface of the light-emitting device to ensure that the optical axes of the inner and outer lenses 404 are aligned.

[0051] The diameter of the inner lens 405 ranges from 0.016 mm to 0.024 mm; the diameter of the outer lens 404 ranges from 0.020 mm to 0.030 mm.

[0052] The diameter range of the inner lens 405 and the diameter range of the outer lens 404 match the pixel size. These diameter ranges ensure that the lens fully covers the light emitted by a single pixel and avoids optical crosstalk between adjacent pixels.

[0053] The surface roughness of the inner lens 405 and the outer lens 404 is less than 5 nanometers.

[0054] A positioning boss is provided on the outer periphery of the inner lens 405 , and an annular groove matching the positioning boss is provided on the inner periphery of the outer lens 404 .

[0055] The outer periphery of the inner lens 405 is provided with a multi-stage positioning structure, including an annular positioning boss and radial positioning columns. The top surface of the annular positioning boss is an inclined surface, forming a self-aligning structure with the inner wall of the outer lens 404. The radial positioning columns are evenly distributed along the circumference, and a guide groove is provided on the side of each positioning column. The inner periphery of the outer lens 404 is provided with an annular groove and a positioning hole that cooperate with the positioning structure. The cross section of the annular groove is dovetail-shaped to prevent the lens from separating. The inner wall of the positioning hole is provided with a convex rib that cooperates with the guide groove. The contact surface of the two layers of lenses is provided with an anti-slip structure, including staggered micro-protrusions and pits to form an interlocking structure.

[0056] The edge area of ​​the inner lens 405 is provided with an annular light limiting member, which includes multiple layers of stepped light-shielding steps. The surface of each step is provided with a sawtooth microstructure, and the inclined surface of the sawtooth faces the center of the lens. When large-angle scattered light is incident on the sawtooth surface, it will be guided to the light-absorbing layer after multiple reflections. A refractive surface is provided between the steps to refract part of the large-angle light back to the center area of ​​the lens.

[0057] The ratio of the height to the diameter of the inner lens 405 ranges from 0.75 to 1.0; the ratio of the height to the diameter of the outer lens 404 ranges from 0.4 to 0.6.

[0058] The above ratio ensures that the lens has sufficient refractive power and avoids stress problems in the lens caused by an excessively large ratio.

[0059] The axes of the inner lens 405 and the outer lens 404 coincide with each other, so that the light can be symmetrically distributed when passing through the two layers of lenses.

[0060] The intensity half-angle range of the lens assembly is 25 degrees to 30 degrees. Within this angle range, the light intensity attenuation does not exceed 50%, ensuring that the light can be effectively received by the collimating optical system while ensuring the uniformity of the brightness of the display device.

[0061] The side wall of the inner lens 405 is provided with a multi-layer refractive structure, including a plurality of concentric annular steps. The surface of each step is a micro-arc surface, which can perform secondary refraction on the incident light. The inner wall of the outer lens 404 is provided with a stepped groove matching the step structure to form a composite refractive interface.

[0062] The surface of the spherical cap of the inner lens 405 is provided with concentric annular microstructures, including periodically changing annular gratings. The grating is divided into multiple areas from the center to the edge, and the grating period in each area gradually increases, and the grating period in adjacent areas changes in equal proportion. In this way, different degrees of diffraction can be produced for light with different incident angles, so that the light tends to be parallel after passing through. The surface of the outer lens 404 is provided with a stepped refractive structure that matches the microstructure of the inner lens 405. The two structures cooperate to form a composite optical system, which can more effectively control the propagation direction of light.

[0063] An annular stress buffering area is provided on the periphery of the lens assembly, which includes a plurality of corrugated elastic support members uniformly distributed along the circumference. Each elastic support member is composed of three layers of corrugated members, the crests and troughs of the corrugations are arranged alternately, and adjacent corrugations are connected by transition arc surfaces. The corrugated member can produce slight deformation in the radial and axial directions, thereby alleviating the stress caused by thermal expansion. One end of the elastic support member is fixedly connected to the inner lens 405, and the other end is slidably connected to the outer lens 404 to form a flexible support structure.

[0064] The light extraction efficiency of the lens assembly ranges from 23% to 27% within a ±15 degree field of view.

[0065] The light extraction efficiency of the lens assembly is improved by 25% to 35% compared to when no lens assembly is provided.

[0066] The display device provided by the present application realizes effective collimation of light through the cooperation of inner and outer double-layer lenses. Specifically, the inner lens 405 is made of silicon nitride, and the outer lens 404 is made of silicon dioxide. The difference in refractive index of the two materials (silicon nitride refractive index 1.75-1.85, silicon dioxide refractive index 1.45-1.50) forms two refractive interfaces on the light propagation path. When the light is emitted from the light emitting layer 402, it first passes through the first refraction of the inner lens 405. Since the inner lens 405 has a higher refractive index, it can refract the light diverging at a large angle into a light of a small angle, and then pass through the second refraction of the outer lens 404, further collimating the light of the small angle, and finally making the divergent light more parallel. Since the height of the inner lens 405 is greater than the height of the outer lens 404, and at least a part of the inner lens 405 is set in the outer lens 404, it is possible to achieve a good light collimation effect through two refractions without increasing the total height of the lens, that is, the light extraction efficiency is improved. This avoids the problem of thin film peeling caused by having to increase the thickness of the silicon dioxide coating in order to obtain the same light extraction efficiency in traditional single-layer lens structures.

[0067] like Figure 4As shown, the embodiment of the present application provides a display device, which adopts a double-layer nested structure of an inner lens 405 and an outer lens 404, wherein the inner lens 405 is made of silicon nitride and the outer lens 404 is made of silicon dioxide. The display device provided by the embodiment of the present application can effectively improve the light extraction efficiency without increasing the total height of the lens, thereby reducing the problem of film peeling caused by the lens being too high, and reducing the yield loss.

[0068] Specifically, the display device provided by the embodiment of the present application includes: a substrate, a driving device layer, a light-emitting device and a lens assembly. The driving device layer is arranged on the substrate. The light-emitting device includes a bonding metal layer 401, a light-emitting layer 402 and a transparent conductive layer 403, the bonding metal layer 401 is arranged on the driving device layer, the light-emitting layer 402 is arranged on the bonding metal layer 401, and the transparent conductive layer 403 is arranged on the light-emitting layer 402. The lens assembly includes an inner lens 405 and an outer lens 404, both of which are arranged on the transparent conductive layer 403, at least a portion of the inner lens 405 is sleeved in the outer lens 404, the diameter of the outer lens 404 is greater than the diameter of the inner lens 405, and the height of the inner lens 405 is greater than the height of the outer lens 404.

[0069] The surfaces of the inner lens 405 and the outer lens 404 are both convex arc surfaces, i.e., spherical crown shapes. The curvature of the surface of the inner lens 405 ranges from 80 to 130, and the curvature of the surface of the outer lens 404 ranges from 60 to 90. The refractive index of the inner lens 405 ranges from 1.75 to 1.85, and the refractive index of the outer lens 404 ranges from 1.45 to 1.50, and the refractive index difference between the two materials is greater than 0.25 and less than 0.4.

[0070] The height of the inner lens 405 ranges from 0.012 mm to 0.018 mm, and the height of the outer lens 404 ranges from 0.010 mm to 0.015 mm. The height of the inner lens 405 is greater than 1.1 times the height of the outer lens 404 and less than 1.5 times the height of the outer lens 404. Within this height range, the stress of the lens can be effectively controlled to avoid cracking or peeling.

[0071] The diameter of the inner lens 405 ranges from 0.016 mm to 0.024 mm, and the diameter of the outer lens 404 ranges from 0.020 mm to 0.030 mm. The diameter of the outer lens 404 is greater than 1.1 times the diameter of the inner lens 405 and less than 1.5 times the diameter of the inner lens 405. This diameter ratio ensures that the lens fully covers the light emitted by a single pixel while avoiding optical crosstalk between adjacent pixels.

[0072] The ratio of the height to the diameter of the inner lens 405 ranges from 0.75 to 1.0, and the ratio of the height to the diameter of the outer lens 404 ranges from 0.4 to 0.6. This ratio relationship ensures that the lens has sufficient refractive power while avoiding stress problems caused by excessively large ratios.

[0073] The axes of the inner lens 405 and the outer lens 404 coincide, and this structure allows the light to maintain a symmetrical distribution when passing through the two layers of lenses. The intensity half-angle range of the lens assembly is 25 degrees to 30 degrees. Within this angle range, the light intensity attenuation does not exceed 50%, ensuring that the light can be effectively received by the subsequent collimating optical system.

[0074] The distance between two adjacent light-emitting devices is 4 microns. This distance combined with the lens structure can achieve a higher display resolution.

[0075] In order to better illustrate the technical effect of the present application, the following is a detailed description through specific embodiments and comparative examples. Table 1 lists the specific parameter configurations of the inner and outer lenses 404 in different embodiments and their corresponding optical performance indicators. Among them, code 1 represents the inner lens 405, code 2 represents the outer lens 404; the radius refers to the radius of the lens; the refractive index of SiO (silicon dioxide) in the material is 1.48, and the refractive index of SiN (silicon nitride) is 1.8; the curvature value is used to define the curvature of the lens surface, so that the lens surface forms a spherical crown shape with a specific curvature; eccentricity represents the height of the lens, that is, the distance from the light-emitting surface to the top of the lens; H / CD represents the ratio of the lens height H to the lens diameter (CD), where the lens diameter (CD) refers to the diameter at the widest point of the bottom of the lens, that is, the diameter where the lens contacts the light-emitting surface, which is equal to twice the radius of the lens; the intensity half angle represents the corresponding luminous angle when the light intensity is reduced to 50%.

[0076]

[0077] Table 1

[0078] Table 2 By analyzing the data in Table 1 and Figure 5 , we can draw the following conclusions: Comparing the existing technology solutions (existing technologies 1 and 2), it can be seen that the single-layer silica lens structure has obvious limitations. Existing technology 1 uses a lower height-to-diameter ratio (H / CD=0.50). Although the structure is stable, the intensity half-angle reaches 34 degrees, but the light extraction effect is not ideal. Existing technology 2 reduces the intensity half-angle to 24 degrees by increasing the height-to-diameter ratio (H / CD=1.00), but the silica lens is too high, which can easily lead to film peeling problems.

[0079] The double-layer lens structure (Examples 1 to 5) provided by the present application exhibits better comprehensive performance. In particular, Example 5 is a preferred solution: the radius of the inner silicon nitride lens is 0.01 mm, the curvature is 125.0, and the height-to-diameter ratio is 0.9375; the radius of the outer silicon dioxide lens is 0.012 mm, the curvature is 83.3, and the height-to-diameter ratio is 0.50. This configuration achieves an intensity half-angle of 27 degrees while maintaining a moderate overall height, achieving a good light collimation effect, that is, improving the light extraction efficiency.

[0080] From the comparison between Example 3 and other examples, it can be seen that the material configuration order of the inner and outer lenses 404 has a significant impact on the optical performance. When silicon dioxide is used as the material of the inner lens 405 and silicon nitride is used as the material of the outer lens 404 (Example 3), the intensity half angle increases to 41 degrees, which verifies that the configuration of using silicon nitride with a higher refractive index as the material of the inner lens 405 and silicon dioxide with a lower refractive index as the material of the outer lens 404 is more conducive to light collimation.

[0081] The parameter comparison between Example 4 and Example 5 shows that by optimizing the curvature and aspect ratio of the lens, the light extraction efficiency can be improved while maintaining structural stability. Example 4 uses a larger aspect ratio (1.875) of the inner lens 405 to obtain a smaller intensity half angle (25.5 degrees), but may cause stress problems. In contrast, Example 5 reduces the aspect ratio of the inner lens 405 to 0.9375. Although the intensity half angle increases slightly (27 degrees), the structure is more stable, which is a better technical solution.

[0082] From the data in Table 2, it can be seen that the preferred solution (Example 5) of the present application has a light collection efficiency of 25% within a viewing angle range of ±15 degrees, while the light collection efficiency of the prior art within the same viewing angle range is only 19%. Through calculation, it can be seen that the efficiency of the preferred solution of the present application is improved by 28% compared with the prior art. This efficiency improvement is due to the double refraction of light by the double-layer lens structure, which limits more light to a viewing angle range of ±15 degrees, thereby improving the receiving efficiency of the subsequent optical system.

[0083] In the display device provided in the embodiment of the present application, after the light is emitted from the light emitting layer 402, it first undergoes the first refraction of the inner lens 405. Since the inner lens 405 is made of silicon nitride and has a refractive index of 1.75 to 1.85, it can strongly refract the light diverging at a large angle, so that its deflection angle is significantly reduced. Subsequently, the light enters the outer lens 404. Since the outer lens 404 is made of silicon dioxide and has a refractive index of 1.45 to 1.50, which is lower than the refractive index of the inner lens 405, the light that has undergone the first refraction can be refracted for the second time. This double refraction effect allows the divergent light to form a collimated beam within the field of view range of ±15 degrees, and the intensity half angle of the lens assembly is controlled within the range of 25 degrees to 30 degrees, ensuring that the light intensity attenuation does not exceed 50%, thereby significantly improving the light extraction efficiency. The height of the inner lens 405 is greater than the height of the outer lens 404. This height difference allows the light to pass through two refraction interfaces of different heights while the total height remains unchanged. Compared with the traditional single-layer silica lens structure, the double-layer lens structure of the present application can improve the light extraction efficiency without increasing the thickness of the silica coating.

[0084] The manufacturing process of the display device provided in the embodiment of the present application includes: A driving device layer is formed on the substrate.

[0085] A bonding metal layer 401, a light emitting layer 402 and a transparent conductive layer 403 are sequentially formed on the driving device layer.

[0086] An inner lens 405 made of silicon nitride material is formed on the transparent conductive layer 403 .

[0087] An outer lens 404 made of silicon dioxide is formed around the inner lens 405 .

[0088] Among them, the inner lens 405 and the outer lens 404 are both patterned after depositing material layers to form a spherical crown surface. This manufacturing method avoids the peeling problem caused by excessive thickness of silicon dioxide coating in the traditional single-layer high lens structure. By reasonably controlling the material and size ratio of the inner and outer lenses 404, the stress of the entire structure is effectively controlled, thereby improving the product yield.

[0089] The embodiments of the present application are described in detail above, and the contents of this specification should not be construed as limiting the scope of protection of the present application.

Claims

1. A display device, characterized in that: include: substrate; A driving device layer, wherein the driving device layer is disposed on the substrate; A light emitting device, the light emitting device comprising a bonding metal layer, a light emitting layer and a transparent conductive layer, the bonding metal layer being arranged on the driving device layer, the light emitting layer being arranged on the bonding metal layer, and the transparent conductive layer being arranged on the light emitting layer; as well as A lens assembly, the lens assembly comprising an inner lens and an outer lens, the inner lens being arranged on the corresponding light-emitting device, the outer lens being arranged at the periphery of the inner lens, and the refractive index of the inner lens being greater than the refractive index of the outer lens.

2. The display device according to claim 1, characterized in that At least a portion of the inner lens is sleeved in the outer lens, the diameter of the outer lens is greater than the diameter of the inner lens, and the height of the inner lens is greater than the height of the outer lens.

3. The display device according to claim 1, characterized in that The surfaces of the inner lens and the outer lens are both convex arc surfaces, and the curvature range of the surface of the inner lens is 80 to 130; the curvature range of the surface of the outer lens is 60 to 90.

4. The display device according to claim 1, characterized in that The material of the inner lens is silicon nitride, and the material of the outer lens is silicon dioxide.

5. The display device according to claim 1, characterized in that The difference in refractive index between the materials of the inner lens and the outer lens is greater than or equal to 0.25 and less than or equal to 0.

4.

6. The display device according to claim 5, characterized in that: The refractive index of the inner lens ranges from 1.7 to 1.9; The refractive index of the outer lens ranges from 1.45 to 1.

50.

7. The display device according to claim 1, characterized in that The height of the inner lens is greater than 1.1 times the height of the outer lens and less than 1.5 times the height of the outer lens.

8. The display device according to claim 1, characterized in that: The diameter of the outer lens is greater than 1.1 times the diameter of the inner lens and less than 1.5 times the diameter of the inner lens.

9. The display device according to claim 1, characterized in that: The ratio of the height to the diameter of the inner lens ranges from 0.75 to 1.0; The ratio of the height to the diameter of the outer lens ranges from 0.4 to 0.

6.

10. The display device according to claim 1, characterized in that The axes of the inner lens and the outer lens coincide with each other.

11. The display device according to claim 1, characterized in that: The intensity half angle of the lens assembly ranges from 25 degrees to 30 degrees.

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