Display device

Abstract

A display device includes a backlight module. The backlight module comprises a substrate, a backlight cavity, a light-emitting element and an optical adjusting layer. The backlight cavity is located on the substrate. The light-emitting element is arranged in the backlight cavity. The optical adjustment layer covers the light-emitting element and fills the remaining space of the backlight cavity. The optical adjustment layer has a refractive index n which is greater than a refractive index n0 of air.

Description

[0001] This application is a divisional application of the invention patent application filed on June 28, 2018, with application number 201810685337.9, and the invention name is “Display Device”. Technical Field

[0002] The present disclosure relates to a display device having a backlight module. Background Art

[0003] Display devices have penetrated into every aspect of people's lives, such as televisions, computers, portable electronic devices, and public devices such as ATMs. Among them, liquid crystal display devices have been developed and widely used. However, liquid crystal display devices must use backlight modules. The backlight module must provide uniform light to the liquid crystal display panel. In addition, as liquid crystal display devices become thinner, the thickness of the backlight modules used therein also tends to be reduced. Based on the above reasons, there is still an expectation for further improvement of the backlight module. Even if the backlight module is applied to other devices, similar expectations still exist. Summary of the invention

[0004] According to some embodiments of the present disclosure, a display device is provided. Such a display device is characterized in that it includes a backlight module. The backlight module includes a substrate, a backlight cavity, a light-emitting element, and an optical adjustment layer. The backlight cavity is located on the substrate. The light-emitting element is disposed in the backlight cavity. The optical adjustment layer covers the light-emitting element and fills the remaining space of the backlight cavity. The optical adjustment layer has a refractive index n, which is greater than the refractive index n of air. 0 . BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

[0006] Figure 1 is a schematic diagram of an exemplary display device.

[0007] Figure 2 is a schematic diagram of an exemplary configuration of a backlight cavity and related components.

[0008] Figure 3 FIG. 4 is a schematic diagram of another exemplary configuration of a backlight cavity and related components.

[0009] Figure 4 FIG. 1 is a schematic diagram of yet another exemplary configuration of a backlight cavity and related components.

[0010] Figure 5 FIG. 4 is a schematic diagram of another exemplary configuration of a backlight cavity and related components.

[0011] Figure 6is a schematic diagram of yet another exemplary configuration of a backlight cavity and related components.

[0012] Figure 7 FIG. 4 is a schematic diagram of yet another exemplary configuration of a backlight cavity and related components.

[0013] Figure 8 The figures are experimental and simulation result diagrams of the embodiments and comparative examples of the backlight module.

[0014] Explanation of symbols:

[0015] 1: Display device

[0016] 10: Display Panel

[0017] 11: Liquid crystal control layer

[0018] 12: Polarizing plate

[0019] 15: Optical Adjustment Layer

[0020] 20: Backlight module

[0021] 21: Substrate

[0022] 22: Backlight cavity

[0023] 23: Light-emitting element

[0024] 24: Diffusion layer

[0025] 25: Diffusion layer

[0026] 26: Diffusion layer

[0027] 27: Prism layer

[0028] 28: Brightening film

[0029] 29: Sidewall

[0030] 102: Base

[0031] 104: Phosphorescent structure

[0032] 106: Reflection layer

[0033] 108: Optical transparent adhesive

[0034] 112: Shading element

[0035] 114: Filling layer

[0036] 116: Optical transparent adhesive

[0037] 122: Encapsulation layer

[0038] 124: Phosphorescent layer

[0039] 126: Optical transparent adhesive

[0040] 132: Phosphorescent layer

[0041] 151: Optical Adjustment Layer

[0042] 152: Optical Adjustment Layer

[0043] 153: Optical Adjustment Layer

[0044] 154: Optical Adjustment Layer

[0045] 155: Optical Adjustment Layer

[0046] 156: Optical Adjustment Layer

[0047] 162: Medium

[0048] 164: Diffuse particles

[0049] 172: First optical adjustment layer

[0050] 174: Second optical adjustment layer

[0051] 221: Configuration

[0052] 222: Configuration

[0053] 223: Configuration

[0054] 224: Configuration

[0055] 225: Configuration

[0056] 226: Configuration

[0057] C1, C2, C3, C4, C5, C6, C7, C8: Curve

[0058] OD: backlight cavity height

[0059] P: Pitch DETAILED DESCRIPTION

[0060] The following will be described in more detail with reference to the accompanying drawings for various different embodiments. The embodiments and drawings provided by the present disclosure are only for description and explanation purposes and are not for limitation purposes. For example, the devices, elements, and / or materials mentioned below, etc., can be replaced with other applicable devices, elements, and / or materials, or other applicable devices, elements, and / or materials can be added, or the devices, elements, and / or materials present in certain embodiments and drawings can be removed, where feasible. When describing the positional relationship of two elements such as "upper", "lower", etc., these two elements can directly contact each other, or there may be other elements in between. For another example, for the sake of clarity, the elements in the drawings may not be drawn according to the actual scale. In addition, some elements and / or element symbols may be omitted from certain drawings. The common symbols in the drawings mean common elements. It can be expected that the elements and features in one embodiment can be advantageously incorporated into another embodiment without further elaboration.

[0061] Please refer to Figure 1 , which shows an exemplary display device 1. The display device 1 includes a display panel 10 and a backlight module 20. The display panel 10 is disposed on the backlight module 20.

[0062] The display panel 10 is, for example, a liquid crystal display panel. Figure 1 The liquid crystal control layer 11 and the polarizing plate 12 are shown in the figure. The two polarizing plates 12 are respectively arranged on the upper side and the lower side of the liquid crystal control layer 11. In some embodiments, the liquid crystal control layer 11 includes two substrates and a liquid crystal layer, and the liquid crystal layer is arranged between the two substrates. The liquid crystal control layer 11 may further include an alignment layer, an electrode layer, etc.

[0063] The backlight module 20 according to the embodiment includes a substrate 21, a backlight cavity 22, a light-emitting element 23, and an optical adjustment layer 15. The backlight cavity 22 is located on the substrate 21. A plurality of light-emitting elements 23 are disposed in the backlight cavity 22. The optical adjustment layer 15 covers the light-emitting element 23 and fills the remaining space of the backlight cavity 22. For example, the substrate 21 may be a circuit board, a glass substrate, or a polymer substrate, and the circuit board may be, for example, a thin film transistor glass substrate, or a thin film transistor polyimide (PI) substrate. The glass substrate and the polymer substrate may also include circuits or active components. The substrate 21 may also further include a reflective layer (not shown), or be formed of a material having reflective properties. The light-emitting element 23 may be a light-emitting diode (LED), a microlight-emitting diode or a mini light-emitting diode, or other appropriate light-emitting elements, but the present disclosure is not limited thereto. The chip size of the light emitting diode is about 300 microns (μm) to 10 millimeters (mm), the chip size of the mini LED is about 100 microns to 300 microns, and the chip size of the micro LED is about 1 micron to 100 microns, but the present disclosure is not limited thereto. In some embodiments, the display device 1 may be, for example, a flexible display device, a touch display device, or a curved display device, but the present disclosure is not limited thereto. The light emitting element 23 may have a pitch P. For example, the pitch P may be the distance from the center of the light emitting element 23 to the center of an adjacent light emitting element 23. The pitch P may also be the distance from the edge of the light emitting element 23 to the corresponding edge of the adjacent light emitting element 23. The optical adjustment layer 15 has a refractive index n, which is greater than the refractive index n of air. 0. For example, n may be greater than or equal to 1.2 and less than or equal to 2, such as 1.4, or 1.7. In some embodiments, the backlight module 20 may further include a diffusion layer 24 and a sidewall 29. The sidewall 29 connects the substrate 21 and the diffusion layer 24, for example, is disposed on the substrate 21 in a surrounding manner. The diffusion layer 24, the sidewall 29 and the substrate 21 define a backlight cavity 22. For example, the upper surface of the substrate 21, the upper surface of the diffusion layer 24, and the inner surface of the sidewall 29 define the backlight cavity 22. The optical adjustment layer 15 may fill at least a portion of the remaining space of the backlight cavity 22, for example, fill 40% to 100% of the remaining space, and in particular, may substantially completely fill the remaining space as shown in the accompanying drawings (that is, substantially fill 100% of the remaining space). The so-called "remaining space" means the space left in the backlight cavity 22 after deducting the light-emitting element 23 and other elements (including but not limited to the reflective layer 106, the optically transparent adhesive 108, and other elements shown or not shown but disposed in the backlight cavity 22), the fixing parts (not shown), and other film layers. The backlight cavity 22 may have a backlight cavity height OD, which is equal to the distance between the upper surface of the substrate 21 and the upper surface of the diffusion layer 24. The configuration of the backlight cavity 22 and related elements is not limited to the following. Figure 1 As shown, it will be referred to in the subsequent paragraphs Figure 2 to Figure 7 For further explanation.

[0064] Please still refer to Figure 1 In some embodiments, the backlight module 20 may further include a diffusion layer 25. The diffusion layer 25 is located on the backlight cavity 22. On the diffusion layer 25, the backlight module may further include at least one optical film layer to further uniformize the light to be provided to the display panel 10. Figure 1 2 shows a diffusion layer 26, a prism layer 27, and a brightness enhancement film 28 stacked from bottom to top, but the number, type, or stacking method of the optical film layers is not limited thereto. In some embodiments, the diffusion layer 24, the diffusion layer 25, and the diffusion layer 26 may be a film, a layer, a plate, or other appropriate forms. In another embodiment, the diffusion layer 24, the diffusion layer 25, and the diffusion layer 26 may have the same or different material composition, thickness, diffusion particle ratio, haze, hardness, process method, or other parameters.

[0065] In terms of reducing the thickness of the backlight module, since the thickness of the substrate, the diffusion layer and the elements thereon do not vary much, whether the backlight module can be thinned basically depends on whether the thickness of the backlight cavity can be reduced. Generally, the backlight cavity is a cavity (air is contained therein, and the optical adjustment layer 15 as disclosed in the present invention is not provided). In order to make the light provided by the backlight module sufficiently uniform, the method used is mostly to increase the height of the cavity so that the light emitted by each light-emitting element can be mixed in a longer path. In addition, there are also cases where other types of optical adjustment elements such as secondary lenses are provided on optical elements such as LEDs to improve the uniformity of light output, but in order to provide sufficient space for such optical adjustment elements, the thickness of the cavity is more difficult to reduce. Taking the provision of a secondary lens as an example, the cavity must have a thickness of at least 8 mm. In contrast, in the present disclosure, by providing an optical adjustment layer 15, the backlight cavity height OD of the backlight cavity 22 can be less than or equal to 2 mm, such as 0.5 mm, 1 mm, or 1.5 mm. In some embodiments, the optical adjustment layer 15 includes or is a transparent material layer. The transmittance of the transparent material layer may be between 70% and 100%, such as 80% or 90%. For example, the material of the optical adjustment layer 151 includes silicone or poly(methyl 2-methylpropenoate), PMMA, but is not limited thereto.

[0066] In order to ensure that the backlight module 20 provides uniform light, in some embodiments, the backlight module 20 of the present disclosure may have a light mixing ratio R 1 Less than 5%, or even less than or equal to 3%, such as 1%, 2%, or 3%, the light mixing ratio R 1 The smaller the value, the more uniform the light provided by the backlight module. 1 The calculation is to take the maximum value Max and the minimum value Min from the result of measuring the light field intensity of the backlight module 20, and then calculate the value of (Max-Min) / Max, and the mixed light ratio R 1 Defined as (Max-Min) / Max and then converted into a percentage (%). For example, an area in the backlight module 20 can be selected, and this area corresponds to 4 to 16 light-emitting elements 23, such as an area corresponding to 2x2 or 4x4 light-emitting elements 23. This area can be located near the center of the backlight module 20, or other appropriate positions. The distribution of the light field intensity in this area of ​​the backlight module 20 is measured. The maximum and minimum values ​​can be obtained from the distribution of the light field intensity, and the light mixing ratio R can be further calculated. 1 .

[0067] In addition, the backlight module 20 may be defined to have a configuration ratio R 2 About configuration ratio R 2The calculation of the backlight cavity height OD and the pitch P of the light emitting element 23 are measured, and then the value of P / OD is calculated. That is, the configuration ratio R 2 In some embodiments, the configuration ratio of the backlight module 20 of the present disclosure is R 2 It can be greater than or equal to 1, for example, it is within the range of greater than or equal to 1 and less than or equal to 4, or even greater than or equal to 2, such as 2, 2.5, 3, or 3.5. Therefore, even if the backlight cavity height OD is reduced to only 1 mm, it is not necessary to densely arrange a large number of light-emitting elements 23 to ensure uniform light output, and the light-emitting elements 23 can even be arranged at a pitch P of more than 2 mm. This helps to further reduce the number of light-emitting elements 23 used, thereby further reducing costs.

[0068] It is understandable that although the above embodiments take liquid crystal display devices as examples, if other display devices are intended to be used with backlight modules, or if electronic devices other than display devices need to use light-emitting modules, these devices can also apply the backlight modules provided by the present disclosure.

[0069] Now, several configuration examples of backlight cavities and related components that can be used in the backlight module 20 of the present disclosure are provided. Figure 2 , which shows an exemplary configuration 221 of a backlight cavity and related elements. In the configuration 221, the backlight module 20 further includes a substrate 102, a phosphor structure 104, a reflective layer 106, and an optically transparent adhesive 108, all of which are located in the backlight cavity 22. It is understandable that other required elements may be further provided in the backlight cavity 22, and / or the aforementioned elements may be appropriately omitted. The substrate 102 is disposed on the substrate 21, and the light-emitting element 23 is disposed on the substrate 102 to be electrically connected to the substrate 21 through the substrate 102. For example, the substrate 102 may include a pad for electrically connecting the light-emitting element 23 and the substrate 21. In some embodiments, a plurality of phosphor structures 104 respectively cover the light-emitting element 23. In one embodiment, the reflective layer 106 is located on the substrate 21 and is disposed around the light-emitting element 23, thereby reflecting the light from the light-emitting element 23 to the substrate 21 to the light-emitting direction of the backlight module 20. The surface of the reflective layer 106 may be substantially flush with the surface of the substrate 102, but is not limited thereto. For example, the surface of the substrate 102 may be higher than the surface of the reflective layer 106. The optical transparent adhesive 108 is located between the reflective layer 106 and the substrate 21 to bond the reflective layer 106 to the substrate 21. For example, if the reflective layer 106 is adhesive, the optical transparent adhesive 108 may be omitted. The reflective layer 106 may also be formed on the substrate 21 by coating. The refractive index n of the optical adjustment layer 151 of the configuration 221 is greater than the refractive index n of air. 0The optical adjustment layer 151 includes a medium, and the material of the medium includes silicone resin or poly(methyl 2-methylpropenoate), PMMA.

[0070] Please refer to Figure 3 , which shows another exemplary configuration 222 of the backlight cavity and related components. The difference between configuration 222 and configuration 221 is that the optical adjustment layer 152 of configuration 222 includes a medium 162 and diffusion particles 164. The diffusion particles 164 are distributed in the medium 162. The medium 162 and the medium of the aforementioned optical adjustment layer 151 can be substantially the same. It should be noted that in the present disclosure, the terms "same" and "different" may be judged by whether they are consistent in terms of materials, structures, uses, etc., but may also be judged only by whether there is a difference in optical properties (especially refractive index). The diffusion particles 164 may have a refractive index n d , n d Greater than the refractive index n of medium 162 m . Refractive index n d The diffusion particles 164 may be greater than or equal to 1.4 and less than or equal to 2.4, such as 1.5 or 2.2. The diffusion particles may also diffuse, scatter, and / or refract the light of the light emitting element 23. The material of the diffusion particles 164 may include polystyrene, polymethyl methacrylate, silicone, silicon dioxide (SiO 2 ), or zirconium dioxide (ZrO 2 ), but is not limited thereto. The diffusion particles 164 may account for 0.01wt% to 90wt% of the optical adjustment layer 152, such as 10wt%, 30wt%, or 50wt%. It is understood that the diffusion particles 164 used can be used to achieve n d Greater than n m In some embodiments, reflective particles may be added to the optical adjustment layer 152, and the material of the reflective particles includes calcium carbonate, lead carbonate, zinc oxide, barium sulfate, or titanium dioxide. The reflective particles may account for 0.05wt% to 50wt% of the optical adjustment layer 152. The optical adjustment layer 152 may include one of the diffusion particles 164 and the reflective particles, or may include both.

[0071] Please refer to Figure 4 , which shows another exemplary configuration 223 of the backlight cavity and related components. The difference between configuration 223 and configuration 221 is that the optical adjustment layer 153 of configuration 223 is a composite layer structure, including layers using different materials and / or having different configurations. For example, Figure 4The optical adjustment layer 153 shown includes a first optical adjustment layer 172 and a second optical adjustment layer 174. The second optical adjustment layer 174 is disposed on the first optical adjustment layer 172. The first optical adjustment layer 172 has a refractive index n. 1 The second optical adjustment layer 174 has a refractive index n 2 , n 2 Not equal to n 1 In one embodiment, if Figure 4 As shown, the first optical adjustment layer 172 and the second optical adjustment layer 174 may both be formed of the materials of the optical adjustment layer as described above, but the first optical adjustment layer 172 and the second optical adjustment layer 174 are formed of different materials. In another embodiment, the diffusion particles or reflective particles as described above may be used in one of the first optical adjustment layer 172 and the second optical adjustment layer 174. In yet another embodiment, diffusion particles and / or reflective particles may be used in both the first optical adjustment layer 172 and the second optical adjustment layer 174. For example, the first optical adjustment layer 172 and the second optical adjustment layer 174 may also use the same material but different diffusion particles. The first optical adjustment layer 172 and the second optical adjustment layer 174 may also use different materials and use different diffusion particles. As long as n is satisfied 2 Not equal to n 1 Under the condition of , the materials and / or configurations of the first optical adjustment layer 172 and the second optical adjustment layer 174 are not particularly limited. Figure 4 As shown, the upper surface of the first optical adjustment layer 172 may be substantially flush with the upper surface of the phosphor structure 104 , but is not limited thereto. For example, the upper surface of the first optical adjustment layer 172 may be higher or lower than the upper surface of the phosphor structure 104 .

[0072] Please refer to Figure 5 , which shows another exemplary configuration 224 of the backlight cavity and related elements. The difference between configuration 224 and configuration 221 is that in configuration 224, the backlight module 20 further includes a shading element 112. A plurality of shading elements 112 are located in the backlight cavity 22 and are respectively located on the light emitting elements 23, thereby reducing the direct upward light, thereby reducing the hot spot of the corresponding light emitting element 23 that may be seen when observing from the light emitting side of the backlight module, thereby improving the uniformity of light emission. In one embodiment, as Figure 5 As shown, the shading element 112 can be disposed between the diffusion layer 24 and the optical adjustment layer 154, the filling layer 114 is disposed between the shading element 112, and the optical transparent adhesive 116 is disposed between the optical adjustment layer 154 and the shading element 112. The filling layer 114 can be formed using the material of the medium of the optical adjustment layer 15 as described above. In another embodiment, the shading element 112 can be directly disposed on the phosphorescent structure 104. In one embodiment, as Figure 5As shown, the shading element 112 may be a rectangular parallelepiped. In other embodiments, the shading element 112 may be an ellipsoid, a pyramid structure, or other shapes. Figure 5 As shown, the shading element 112 has a smooth surface. In another embodiment, a concave-convex structure may be formed on the surface of the shading element 112. In one embodiment, the shading element 112 may be a reflective structure. In another embodiment, the shading element 112 may be a refractive structure. In yet another embodiment, the shading element 112 may be a diffusion structure. As long as the shading element 112 is located above the light emitting element 23 to achieve the effect of reducing the light spot caused by the light emitting element 23 on the light emitting side, there is no need to specifically limit its material, type, and configuration. In addition, it can be understood that the optical adjustment layer 154 of configuration 224 may be similar to the aforementioned optical adjustment layer 151, optical adjustment layer 152, or optical adjustment layer 153 (including the aforementioned various combined application examples).

[0073] Please refer to Figure 6 , which shows another exemplary configuration 225 of the backlight cavity and related components. Configuration 225 adopts a chip on board (COB) design. In configuration 225, the backlight module 20 may include a substrate 21, a light-emitting element 23, an encapsulation layer 122, an optical adjustment layer 155, a phosphor layer 124, and an optically transparent adhesive 126, all of which are located in the backlight cavity 22. In some embodiments, the optically transparent adhesive 126 may be replaced with an optical adjustment layer. It is understandable that other required elements may be additionally provided in the backlight cavity 22, and / or the aforementioned elements may be appropriately omitted. For example, in one embodiment, the encapsulation layer 122 may be omitted. In Figure 6 In the embodiment of the present invention, the encapsulation layer 122 is disposed on the substrate 21 and covers to protect the light-emitting element 23. The optical adjustment layer 155 is disposed on the encapsulation layer 122. The optical adjustment layer 155 may be similar to the aforementioned optical adjustment layer 154. The phosphor layer 124 is disposed on the optical adjustment layer 155, so the optical adjustment layer 155 is located between the substrate 21 and the phosphor layer 124. The material of the phosphor layer 124 may be similar to the phosphor structure 104, or the phosphor material may be dispersed in a medium, which may, for example, contain silicone. As long as the optical adjustment properties similar to the phosphor structure 104 can be achieved, no special restrictions are required. The optically transparent adhesive 126 is disposed on the phosphor layer 124. The optically transparent adhesive 126 is substantially the same as the aforementioned optically transparent adhesive 108, but is not limited thereto. The chip direct packaging design can further reduce the backlight cavity height OD to below 0.6 mm, for example 0.3 mm, or 0.4 mm. Compared with chip scale packaging (CSP) light emitting elements, since the chip scale packaging light emitting elements are larger in size (about 400 μm), the light emitting elements directly packaged by the chip can reduce the backlight cavity height OD.

[0074] Please refer to Figure 7 , which shows yet another exemplary configuration 226 of the backlight cavity and related components. The difference between configuration 226 and configuration 225 is that configuration 226 omits the encapsulation layer 122 and the optically transparent adhesive 126 in configuration 225. Specifically, in configuration 225, the optical adjustment layer 156 directly covers the light emitting element 23 to provide protection thereof. The phosphor layer 132 may have the same optical adjustment properties as the phosphor layer 124. In some embodiments, the phosphor layer 132 may have adhesiveness. For example, the phosphor layer 132 may be a phosphor material mixed in an adhesive, but is not limited thereto.

[0075] From the above embodiments, it can be seen that in the case where the present disclosure is feasible, there is no need to specifically limit the design of the backlight module. In other words, any optical element and supporting design currently available or likely to be developed in the future can be used, and the optical adjustment layer as described in the present disclosure can be filled in the original cavity, thereby further thinning the backlight module while ensuring the uniformity of light output, and even further reducing the number of light-emitting elements used to reduce costs.

[0076] In order to provide a clearer understanding of the backlight module disclosed in the present invention, specific experimental examples of the backlight module and their experimental and simulation results are described below. In the following experimental examples, the same layers or particles use the same materials.

[0077] [Experimental Example 1]

[0078] Experimental Example 1 uses a method similar to Figure 1 The configuration of the backlight module 20 shown in FIG. 1 , wherein the configuration of the backlight cavity 22 and related components is similar to that of Figure 2The design of the five-sided light-emitting element shown. However, Experimental Example 1 does not include the optical adjustment layer 15. That is, the backlight cavity 22 is filled with air. In Experimental Example 1, the substrate 102 has a thickness of 250 μm. The reflective layer 106 has a thickness of 150 μm. The optically transparent adhesive 108 that bonds the reflective layer 106 to the substrate 21 has a thickness of 100 μm. The light-emitting element 23 is disposed on the substrate 102, has a thickness of 100 μm, and a pitch P of 5 mm. The phosphorescent structure 104 is located on the substrate and covers the light-emitting element 23, and has a thickness of 400 μm (starting from the upper surface of the substrate). In order to reduce variables in accordance with the design of the four-sided light-emitting element of Experimental Examples 5 to 8, a layer of polysilicone resin having a thickness of 50 μm is disposed on the side of the diffusion layer 24 facing the substrate 21. A layer of polysilicone adhesive having a thickness of 50 μm is further disposed on the side of this polysilicone resin layer facing the substrate 21. A 500 μm cavity is formed between the layer of silicone adhesive and the reflective layer 106. The diffusion layer 24 has a transmittance of 82%, a haze of 93%, and a thickness of 50 μm. Therefore, the overall backlight cavity height OD is 1 mm. The diffusion layer 25 has a transmittance of 40%, a haze of 99%, and a thickness of 1 mm. The diffusion layer 26 has a thickness of 130 μm. The prism layer 27 has a thickness of 155 μm. The brightness enhancement film 28 has a thickness of 390 μm.

[0079] [Experimental Example 2]

[0080] The difference between Experimental Example 2 and Experimental Example 1 is that Experimental Example 2 is configured as follows Figure 2 The optical adjustment layer 151 shown is formed only of a medium. The optical adjustment layer 151 is formed of a silicone resin and has a thickness of 500 μm. Above it are a layer of silicone adhesive and a layer of silicone resin added to match Experimental Examples 5 to 8. The optical adjustment layer 151 formed of silicone resin, and the layer of silicone adhesive and another silicone resin layer above it have substantially the same or similar refractive index.

[0081] [Experimental Example 3]

[0082] The difference between Experimental Example 3 and Experimental Example 2 is that Experimental Example 3 uses Figure 3 The optical adjustment layer 152 shown. The optical adjustment layer 152 further includes diffusion particles 164 distributed in the medium. The diffusion particles 164 account for 5 wt % of the entire optical adjustment layer 152.

[0083] [Experimental Example 4]

[0084] The difference between Experimental Example 4 and Experimental Example 3 is that in Experimental Example 4, the optical adjustment layer 152 includes reflective particles instead of diffusing particles. The reflective particles account for 0.5 wt % of the entire optical adjustment layer.

[0085] [Experimental Example 5]

[0086] Experimental Example 5 also uses a method similar to Figure 1 The configuration of the backlight module 20 shown in FIG. 1 is similar to that of the backlight module 20, but the configuration of the backlight cavity 22 and related components is similar to that of the backlight module 20. Figure 5 The design of the chip-scale packaged four-sided luminous element is shown. Similar to Experimental Example 1, Experimental Example 5 also does not include the optical adjustment layer 15. The difference between Experimental Example 5 and Experimental Example 1 is that in the layer of polysilicone resin with a thickness of 50 μm located on the layer of polysilicone adhesive, a plurality of reflective structures 112 are arranged at positions corresponding to the optical elements 23. The reflective structures have a thickness of 50 μm.

[0087] [Experimental Example 6]

[0088] The difference between Experimental Example 6 and Experimental Example 5 is that Experimental Example 6 is configured as follows Figure 2 The optical adjustment layer 151 shown is formed only of a medium. The optical adjustment layer 151 is formed of a silicone resin and has a thickness of 500 μm. Thereon are a layer of a silicone adhesive and a layer of a silicone resin in sequence. The optical adjustment layer 151 formed of silicone resin, and the layer of silicone adhesive and another silicone resin layer thereon have substantially the same or similar refractive index.

[0089] [Experimental Example 7]

[0090] The difference between Experimental Example 7 and Experimental Example 6 is that Experimental Example 7 uses Figure 3 The optical adjustment layer 152 shown. The optical adjustment layer 152 further includes diffusion particles 164. The diffusion particles 164 account for 5 wt % of the entire optical adjustment layer 152.

[0091] [Experimental Example 8]

[0092] The difference between Experimental Example 8 and Experimental Example 6 is that in Experimental Example 8, the optical adjustment layer 152 includes reflective particles instead of diffusing particles. The reflective particles account for 0.5 wt % of the entire optical adjustment layer 152 .

[0093] [Experimental and simulation methods]

[0094] Measuring the light mixing ratio R of the backlight modules of Experimental Examples 1 to 8 1 Based on this simulation, the light field intensity distribution in each experimental example is maintained at 1 mm in the backlight cavity height OD but the pitch P is gradually changed to obtain the light mixing ratio. Figure 8 The trend change diagram shown in the figure shows that the horizontal axis is the configuration ratio R 2 The vertical axis is the light mixing ratio R 1C1 to C8 represent the curves of Experimental Examples 1 to 8 respectively. Through these curves, we can understand how to choose the configuration ratio R when the mixing rate of the display needs to be lower than a certain value (the lower the more uniform), 2 For example, as shown in Table 1, when the light mixing ratio R 1 When the preset value is less than 3% (such as Figure 8 The configuration ratio R corresponding to each embodiment can be found from the figure. 2 This also means that the backlight cavity height OD is maintained at 1mm, and the mixing ratio R 1 When the ratio R reaches a certain value, for example, less than 3%, the maximum pitch of the light-emitting element can be enlarged. 2 The number of light emitting elements required when actually applied to a specified backlight module is simulated, and the reduction ratio of the light emitting elements is further normalized. The results are also listed in Table 1.

[0095] [Results and Discussion]

[0096] Table 1

[0097]

[0098]

[0099] from Figure 8 It can be seen that, under the same configuration ratio, using an optical adjustment layer can obtain a smaller or better light mixing ratio for a five-sided LED backlight module, which can improve the light uniformity of the backlight device. Using an optical adjustment layer containing diffusion particles can obtain a better light mixing ratio for both five-sided and four-sided light-emitting element backlight modules. Figure 8 As shown in Table 1, when the backlight cavity height OD is maintained at 1 mm, the required light mixing ratio R 1 Reaching an appropriate level, the configuration ratio of the backlight module configured with an optical adjustment layer (only medium and diffusion examples) in Experimental Examples 2, 3, 6, and 7 can be increased to more than 2.00, or even to 4.75. This can effectively reduce the number of optical elements required for the backlight module, as shown in Table 1. Therefore, by setting an optical adjustment layer, the present disclosure can reduce the backlight cavity height OD to less than 2 mm while ensuring the uniformity of light output, and can even reduce the number of optical elements used to reduce costs.

[0100] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. An electronic device, It is characterized in that include: substrate; A side wall connected to the substrate, wherein the inner surface of the side wall and the first diffusion layer define the backlight cavity; A plurality of light-emitting elements are disposed on the substrate; as well as an optical unit covering at least two of the plurality of light emitting elements; Wherein, in a cross section of the electronic device, part of the optical unit is disposed between two adjacent light-emitting elements among the at least two light-emitting elements among the plurality of light-emitting elements, and the thickness of the side wall is greater than the height of the optical unit.

2. The electronic device according to claim 1, It is characterized in that The optical unit includes a transparent material.

3. The electronic device according to claim 1, It is characterized in that The optical unit includes an organic material.

4. The electronic device according to claim 3, It is characterized in that The organic material includes silicone or acrylic.

5. The electronic device according to claim 1, It is characterized in that The optical unit includes a lens.

6. The electronic device according to claim 1, It is characterized in that Also included is a pad for electrically connecting one of the plurality of light emitting elements and the substrate.

7. The electronic device according to claim 1, It is characterized in that Also included is a reflective layer disposed between the substrate and the optical unit.

8. The electronic device according to claim 7, It is characterized in that Also included is an optically transparent adhesive disposed between the substrate and the reflective layer.

9. The electronic device according to claim 1, It is characterized in that The transmittance of the optical unit is between 70% and 100%.

10. The electronic device according to claim 1, It is characterized in that The optical unit includes a medium and a plurality of diffusion particles distributed in the medium.

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