LED display module and LED display device having the same

Abstract

The utility model provides an LED display module and an LED display device having the same, wherein the LED display module comprises: a substrate; a plurality of LED light-emitting units, arranged on the front of the substrate, each LED light-emitting unit comprising a light-emitting top surface and a plurality of light-emitting side surfaces; a reflective layer, arranged on the front of the substrate, a plurality of reflective holes corresponding to the plurality of LED light-emitting units are arranged through the reflective layer, each reflective hole comprising a plurality of parabolic reflective surfaces corresponding to the plurality of light-emitting side surfaces of the LED light-emitting unit, and in a direction away from the substrate, the lateral distance between the parabolic reflective surface and the LED light-emitting unit gradually increases; a protective adhesive layer, arranged above the reflective layer and covering the plurality of LED light-emitting units. The technical solution of the present application can effectively solve the problem of high heat dissipation cost of LED display modules in the related art.

Description

Technical Field

[0001] The utility model relates to the technical field of LED display, in particular to an LED display module and an LED display device having the same. Background Art

[0002] Nowadays, as people's requirements for LED display quality are getting higher and higher, in order to meet the needs, the spacing of direct display LEDs has gradually become smaller, and the picture quality has become higher and higher at the same observation distance; for this reason, the number of light-emitting chips per unit area has also increased accordingly.

[0003] A light-emitting chip can be regarded as a point light source, which emits light radially in all directions and in front, while the light received by the viewer is generally vertically emitted light or light with a small angle to the vertical direction, and the remaining light is wasted, which will cause a loss of light intensity. In order to achieve a certain level of brightness requirements, a greater power requirement is required, which will cause an increase in the heat generated per unit area of ​​the module, greatly increase the heat dissipation requirements, and greatly increase the heat dissipation costs. Utility Model Content

[0004] The main purpose of the utility model is to provide an LED display module and an LED display device having the same, so as to solve the problem of high heat dissipation cost of the LED display module in the related art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the utility model, there is provided an LED display module, comprising: a substrate; a plurality of LED light-emitting units, arranged on the front side of the substrate, each LED light-emitting unit comprising a light-emitting top surface and a plurality of light-emitting side surfaces; a reflective layer, arranged on the front side of the substrate, a plurality of reflective holes corresponding to the plurality of LED light-emitting units being penetrated through the reflective layer, each reflective hole comprising a plurality of parabolic reflective surfaces corresponding to the plurality of light-emitting side surfaces of the LED light-emitting unit, and in a direction away from the substrate, a lateral distance between the parabolic reflective surface and the LED light-emitting unit gradually increases; and a protective adhesive layer, arranged above the reflective layer and covering the plurality of LED light-emitting units.

[0006] Furthermore, the focal points of the multiple parabolic reflection surfaces overlap to form a common focus, and the distance between the geometric center of the LED light-emitting unit and the common focus is between 0 μm and 30 μm.

[0007] Furthermore, a line connecting the lowest point of the parabolic reflection surface and the center of the bottom surface of the LED light-emitting unit has a first angle with the vertical direction, and the first angle is greater than or equal to 60°.

[0008] Furthermore, a second angle is formed between a line connecting the highest point of the parabolic reflecting surface and the center of the light-emitting top surface and the vertical direction, and the second angle is less than or equal to 75°.

[0009] Furthermore, the distance between two adjacent reflective holes is less than or equal to 30 μm.

[0010] Furthermore, the parabolic reflecting surface is a total reflection surface.

[0011] Furthermore, the top surface of the protective adhesive layer is higher than the top surface of the reflective layer.

[0012] Further, the flatness of the top surface of the protective adhesive layer is ±0.1 mm; and / or the roughness of the top surface of the protective adhesive layer is between Ra0.4 and Ra0.2.

[0013] Furthermore, the LED display module also includes a functional film layer arranged above the protective adhesive layer.

[0014] According to another aspect of the present invention, there is provided an LED display device, comprising an LED display module, wherein the LED display module is the above-mentioned LED display module.

[0015] By applying the technical solution of the utility model, a plurality of LED light-emitting units are arranged on the front side of the substrate, and the reflective layer includes a plurality of reflective holes corresponding to the plurality of LED light-emitting units, that is, each reflective hole is provided with an LED light-emitting unit, and each reflective hole includes a plurality of parabolic reflective surfaces corresponding to the plurality of light-emitting side surfaces of the LED light-emitting unit, and each parabolic reflective surface can reflect the obliquely emitted light emitted by the corresponding light-emitting side surface, so that the emission path of this part of the light is changed and emitted in a direction perpendicular to the substrate or in a direction with a small angle different from the vertical direction, and the light emitted by the light-emitting top surface itself is emitted vertically, that is, the setting of the reflective holes enables the light emitted by the LED light-emitting unit to be emitted vertically as much as possible, reducing the loss of light intensity. Furthermore, compared with the solutions in the related art, the LED display module of the present application requires less power to achieve the brightness requirement of the same order of magnitude, and thus the demand for heat dissipation is also less. Therefore, the technical solution of the present application can effectively solve the problem of high heat dissipation cost of LED display modules in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0017] Figure 1 A cross-sectional schematic diagram of an embodiment of an LED display module according to the utility model is shown;

[0018] Figure 2 Shows Figure 1An enlarged view of a portion of the structure of an LED display module;

[0019] Figure 3 Shows Figure 1 A cross-sectional schematic diagram of a substrate, an LED light-emitting unit, a reflective layer and a protective adhesive layer of an LED display module;

[0020] Figure 4 Shows Figure 3 An enlarged view of a part of the structure of the substrate, LED light-emitting unit, reflective layer and protective adhesive layer;

[0021] Figure 5 Shows Figure 3 An enlarged view of the substrate, LED light-emitting unit, reflective layer and protective adhesive layer at A;

[0022] Figure 6 Shows Figure 1 A cross-sectional schematic diagram of a substrate, an LED light-emitting unit and a reflective layer of an LED display module;

[0023] Figure 7 A schematic diagram showing the use of a jig to form a reflective layer on the surface of a substrate;

[0024] Figure 8 Shows Figure 1 A three-dimensional structural schematic diagram of a partial structure of an LED display module;

[0025] Fig. 9 Shows the preparation Figure 1 Flow chart of LED display module.

[0026] The above drawings include the following reference numerals:

[0027] 10. Substrate;

[0028] 20. LED light-emitting unit; 21. Light-emitting top surface; 22. Light-emitting side surface; 23. Solder paste;

[0029] 30, reflecting layer; 31, reflecting hole; 32, parabolic reflecting surface; 321, first reflecting surface; 322, second reflecting surface;

[0030] 40. Protective rubber layer;

[0031] 50. Functional film layer;

[0032] 60. Jig; 61. Avoidance groove;

[0033] V, vertical direction; A1, first angle; A2, second angle; D, dimension of the top surface of the protective adhesive layer higher than the top surface of the reflective layer. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0035] like Figures 1 to 6 As shown, the present application provides an LED display module, including: a substrate 10, a plurality of LED light-emitting units 20, a reflective layer 30 and a protective adhesive layer 40. The plurality of LED light-emitting units 20 are arranged on the front of the substrate 10, and each LED light-emitting unit 20 includes a light-emitting top surface 21 and a plurality of light-emitting side surfaces 22; the reflective layer 30 is arranged on the front of the substrate 10, and a plurality of reflective holes 31 corresponding to the plurality of LED light-emitting units 20 are penetrated on the reflective layer 30, and each reflective hole 31 includes a plurality of parabolic reflective surfaces 32 corresponding to the plurality of light-emitting side surfaces 22 of the LED light-emitting unit 20, and in the direction away from the substrate 10, the lateral distance between the parabolic reflective surface 32 and the LED light-emitting unit 20 gradually increases; the protective adhesive layer 40 is arranged above the reflective layer 30 and covers the plurality of LED light-emitting units 20.

[0036] According to the technical solution of this embodiment, a plurality of LED light-emitting units 20 are arranged on the front side of the substrate 10, and the reflective layer 30 includes a plurality of reflective holes 31 corresponding to the plurality of LED light-emitting units 20, that is, each reflective hole 31 is provided with an LED light-emitting unit 20, and each reflective hole 31 includes a plurality of parabolic reflective surfaces 32 corresponding to the plurality of light-emitting side surfaces 22 of the LED light-emitting unit 20, and each parabolic reflective surface 32 can reflect the obliquely emitted light emitted by the corresponding light-emitting side surface 22, so that the emission path of this part of the light changes and is emitted in a direction perpendicular to the substrate 10 or in a direction with a small angle with the vertical direction, and the light emitted by the light-emitting top surface 21 itself is emitted vertically, that is, the setting of the reflective holes 31 enables the light emitted by the LED light-emitting unit 20 to be emitted vertically as much as possible, reducing the loss of light intensity. Furthermore, compared with the solutions in the related art, the LED display module of this embodiment requires less power to achieve the same level of brightness requirements, and thus the demand for heat dissipation is also less. Therefore, the technical solution of this embodiment can effectively solve the problem of high heat dissipation cost of LED display modules in the related art.

[0037] In this embodiment, the reflective layer 30 can effectively control and improve the light emission characteristics, and can protect the LED light-emitting unit 20 from the influence of the external environment. The design of the reflective layer 30 has an important influence on the performance, efficiency and life of the LED light-emitting module.

[0038] Specifically, Figure 1 As shown, the lateral direction used in describing the embodiment of the present application is a direction parallel to the substrate 10, and the vertical direction or longitudinal direction used is a direction perpendicular to the substrate 10, wherein the side where the LED light-emitting unit 20 is provided is the front side of the substrate 10, and the other side is the rear side of the substrate 10. The bottom of the LED light-emitting unit 20 is provided with a pin, and the front of the substrate 10 is provided with a pad. The LED light-emitting unit 20 is connected to the substrate 10 (specifically a PCB substrate) by soldering with solder paste 23 between the pin and the pad.

[0039] It should be noted that the parabolic reflecting surface 32 can reflect light parallel to its axis to a common focus, or reflect light emitted by a light source located at the focus into a beam of parallel light. The principle of reflecting light emitted by a light source located at the focus into a beam of parallel light is applied in this embodiment, so that the light emitted by the light-emitting side 22 can be collimated as much as possible.

[0040] Specifically, Figure 8 As shown, in this embodiment, the LED light-emitting unit 20 is a rectangular parallelepiped structure, which has a light-emitting top surface 21, two long-side light-emitting side surfaces and two short-side light-emitting side surfaces. Correspondingly, the multiple parabolic reflection surfaces 32 include two first reflection surfaces 321 corresponding to the two long-side light-emitting side surfaces and two second reflection surfaces 322 corresponding to the two short-side light-emitting side surfaces. Among them, the first reflection surface 321 is obtained by translating the second parabola passing through the first symmetry plane of the LED light-emitting unit 20 along the long side direction of the LED light-emitting unit 20, and the second reflection surface 322 is obtained by translating the second parabola passing through the second symmetry plane of the LED light-emitting unit 20 along the short side direction of the LED light-emitting unit 20. The first symmetry plane is a symmetry plane perpendicular to the substrate 10 and perpendicular to the length direction of the LED light-emitting unit 20, and the second symmetry plane is a symmetry plane perpendicular to the substrate 10 and perpendicular to the width direction of the LED light-emitting unit 20.

[0041] like Figures 1 to 6As shown, the foci of multiple parabolic reflective surfaces 32 overlap to form a common focus, and the distance between the geometric center of the LED light-emitting unit 20 and the common focus is between 0μm and 30μm. It should be noted that the "common focus" here refers to the focus of the first parabola and the second parabola. The distance between the geometric center of the LED light-emitting unit 20 and the common focus is between 0μm and 30μm, which can ensure a good light collimation effect and control the processing cost of the reflective layer 30 within a reasonable range. Preferably, the distance between the geometric center of the LED light-emitting unit 20 and the common focus can be 0μm, 10μm, 15μm, 20μm, 25μm or 30μm.

[0042] Specifically, Figure 7 As shown, when processing the reflective layer 30 of this embodiment, a customized jig 60 can be used. Specifically, the shape of the bottom surface of the jig 60 is adapted to the shape of the top of the reflective layer 30 to be processed, that is, the jig 60 is hollowed out corresponding to the position of the solid structure of the reflective layer 30; corresponding to the position of the reflective hole 31, the jig 60 is a solid structure and an avoidance groove 61 for avoiding the LED light-emitting unit 20 is provided on the solid structure. Preferably, the height of the avoidance groove 61 is greater than the height of the LED light-emitting unit 20 to avoid damaging the light-emitting top surface 21 of the LED light-emitting unit 20.

[0043] The aforementioned “processing cost of the reflective layer 30 ” mainly refers to the processing and manufacturing cost of the jig 60 .

[0044] It should be noted that the jig 60 needs to be customized for different LED display modules. For example, when the pixel pitch of the LED display module is different, the spacing between the hollowed-out recesses on the jig 60 needs to be adjusted accordingly; when the size of the LED light-emitting unit 20 is different, the parameters of the first parabola and the second parabola need to be adjusted accordingly. A mark or structure for mutual limiting and positioning can be set between the jig 60 and the substrate 10 so that the jig 60 can be quickly and accurately placed on the substrate 10, while preventing the LED light-emitting unit 20 from being worn.

[0045] like Figure 3 and Figure 4As shown, there is a first angle A1 between the line between the lowest point of the parabolic reflective surface 32 and the center of the bottom surface of the LED light-emitting unit 20 and the vertical direction V, and the first angle A1 is greater than or equal to 60°. The first angle A1 is set to be greater than or equal to 60°, so that the lowest point of the parabolic reflective surface 32 is located below almost all the light emitted by the corresponding light-emitting side surface 22, thereby avoiding the light from being directly lost by irradiating the bottom of the parabolic reflective surface 32, thereby improving the light extraction efficiency. The first angle A1 of the first reflective surface 321 and the second reflective surface 322 may be different. In this case, it is necessary to make the first angle A1 of the first reflective surface 321 and the first angle A1 of the second reflective surface 322 meet the above requirements. Preferably, the first angle A1 can be selected between 60° and 75°, for example, it can be 60°, 65°, 70° or 75°.

[0046] like Figure 3 and Figure 4 As shown, there is a second angle A2 between the line between the highest point of the parabolic reflecting surface 32 and the center of the light-emitting top surface 21 and the vertical direction V, and the second angle A2 is less than or equal to 75°. The second angle A2 is set to be less than or equal to 75°, so that the highest point of the parabolic reflecting surface 32 is located above almost all the light emitted by the corresponding light-emitting side surface 22, thereby preventing the light from being directly emitted in an oblique direction without being reflected by the parabolic reflecting surface 32, thereby improving the light extraction efficiency. The second angle A2 of the first reflecting surface 321 and the second reflecting surface 322 may be different. In this case, it is necessary to make the second angle A2 of the first reflecting surface 321 and the second angle A2 of the second reflecting surface 322 meet the above requirements. Preferably, the second angle A2 can be selected between 60° and 75°, for example, it can be 60°, 65°, 70° or 75°.

[0047] like Figure 1 , Figure 2 and Figure 8 As shown, the spacing between two adjacent reflective holes 31 is less than or equal to 30μm. When the spacing between two adjacent reflective holes 31 is less than or equal to 30μm, the precision requirement of the fixture 60 is moderate, and the light output effect of the LED display module is better. It should be noted that the above-mentioned "spacing between two adjacent reflective holes 31" refers to the minimum spacing between the tops of two adjacent reflective holes 31.

[0048] Preferably, the parabolic reflective surface 32 is a total reflection surface (ie, the transmittance of the parabolic reflective surface 32 is zero). This configuration allows the light emitted from the light emitting side surface 22 of the LED light emitting unit 20 to be reflected as much as possible, thereby reducing the light intensity loss on the emission path.

[0049] The total reflection surface can be formed by attaching or spraying a total reflection film on the inner surface of the reflection hole 31, or the entire reflection layer 30 can be formed directly by using a total reflection material.

[0050] like Figures 1 to 5 As shown, the top surface of the protective rubber layer 40 is higher than the top surface of the reflective layer 30. This configuration enables the protective rubber layer 40 to not only protect the LED light-emitting unit 20, but also protect the parabolic reflective surface 32, thereby ensuring the reflective effect of the parabolic reflective surface 32. Preferably, the top surface of the protective rubber layer 40 is higher than the top surface of the reflective layer 30 by a dimension greater than or equal to 0.3 mm.

[0051] In this embodiment, the flatness of the top surface of the protective adhesive layer 40 is ±0.1 mm. Specifically, the protective adhesive layer 40 is a transparent epoxy resin adhesive layer, and the light emitted from the light-emitting top surface 21 and the light-emitting side surface 22 will eventually be emitted through the top surface of the protective adhesive layer 40. When the flatness of the top surface of the protective adhesive layer 40 is within the above range, the light can be emitted in a direction perpendicular to the substrate 10 or in a direction with a small angle different from the vertical direction, thereby ensuring the display effect and reducing the light intensity loss of the LED light-emitting module.

[0052] In this embodiment, the roughness of the top surface of the protective rubber layer 40 is between Ra0.4 and Ra0.2. The presence of thorn-like protrusions or depressions on the top surface of the protective rubber layer 40 will change the refraction direction of light at these positions, thereby forming brighter light spots at these positions, affecting the overall display effect. Setting the roughness of the top surface of the protective rubber layer 40 between Ra0.4 and Ra0.2 can avoid the formation of thorn-like protrusions or depressions on the top surface of the protective rubber layer 40 as much as possible, thereby ensuring the display effect of the LED display module. Preferably, the roughness of the top surface of the protective rubber layer 40 can be Ra0.4, Ra0.3 or Ra0.2.

[0053] like Figure 1 and Figure 2 As shown, the LED display module further includes a functional film layer 50 disposed above the protective adhesive layer 40. Specifically, different functional films can be selected according to requirements (eg, improving display contrast, anti-glare, etc.) to further improve the light output effect of the LED display module.

[0054] Fig. 9The flowchart of preparing the LED display module of the present embodiment is shown. In the specific preparation, the LED light-emitting unit 20 is first soldered to the substrate 10 by the solder paste 23; then the jig 60 is fixed to the front of the substrate 10; after the jig 60 is fixed, the air in the hollowed-out concave portion of the jig 60 is extracted to avoid bubbles between the reflective layer 30 formed by the processing and the substrate 10, resulting in a loose bond, and then the liquid raw material for forming the reflective layer 30 is injected into the hollowed-out concave portion of the jig 60, and then the substrate 10 and the jig 60 injected with the liquid raw material are heated to a preset temperature (the preset temperature is lower than the softening temperature of the solder paste 23 to avoid affecting the soldering of the LED light-emitting unit 20). Stability), so that the reflective layer 30 is completely cured. When the reflective layer 30 is cured, the jig 60 is withdrawn, and the reflective layer 30 is completely bonded to the substrate 10; then the protective adhesive layer 40 is encapsulated (the epoxy resin A / B adhesive layer can be formed by spraying, injection, etc.), and then the epoxy resin A / B adhesive layer is completely cured by ultraviolet curing; then the protective adhesive layer 40 is polished to make the top surface of the protective adhesive layer 40 meet the corresponding flatness and roughness requirements; finally, the functional film layer 50 is encapsulated or laminated on the top surface of the protective adhesive layer 40 (it should be noted that the functional film layer 50 also needs to have a certain light transmittance while realizing the corresponding function).

[0055] The present application also provides an LED display device, and an embodiment of the LED display device of the present application includes an LED display module, wherein the LED display module is the above-mentioned LED display module. The above-mentioned LED display module can effectively solve the problem of high heat dissipation cost of the LED display module in the related art, and the LED display device having the above-mentioned LED display module also has the above-mentioned advantages.

[0056] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present utility model; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0057] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.

[0058] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An LED display module, characterized in that: include: base(10); A plurality of LED light-emitting units (20) are arranged on the front surface of the substrate (10), each of the LED light-emitting units (20) comprising a light-emitting top surface (21) and a plurality of light-emitting side surfaces (22); A reflective layer (30) is arranged on the front side of the substrate (10), and a plurality of reflective holes (31) corresponding one-to-one to the plurality of LED light-emitting units (20) are provided through the reflective layer (30), and each of the reflective holes (31) comprises a plurality of parabolic reflective surfaces (32) corresponding one-to-one to the plurality of light-emitting side surfaces (22) of the LED light-emitting unit (20), and in a direction away from the substrate (10), a lateral distance between the parabolic reflective surface (32) and the LED light-emitting unit (20) gradually increases; A protective adhesive layer (40) is disposed above the reflective layer (30) and covers the plurality of LED light-emitting units (20).

2. The LED display module according to claim 1, characterized in that: The focal points of the plurality of parabolic reflection surfaces (32) overlap to form a common focus, and the distance between the geometric center of the LED light-emitting unit (20) and the common focus is between 0 μm and 30 μm.

3. The LED display module according to claim 1, characterized in that: A first angle (A1) is formed between a line connecting the lowest point of the parabolic reflection surface (32) and the center of the bottom surface of the LED light-emitting unit (20) and the vertical direction (V), and the first angle (A1) is greater than or equal to 60°.

4. The LED display module according to claim 1, characterized in that: A second angle (A2) is formed between a line connecting the highest point of the parabolic reflection surface (32) and the center of the light-emitting top surface (21) and the vertical direction (V), and the second angle (A2) is less than or equal to 75°.

5. The LED display module according to claim 1, characterized in that: The distance between two adjacent reflection holes (31) is less than or equal to 30 μm.

6. The LED display module according to claim 1, characterized in that: The parabolic reflection surface (32) is a total reflection surface.

7. The LED display module according to any one of claims 1 to 6, characterized in that: The top surface of the protective adhesive layer (40) is higher than the top surface of the reflective layer (30).

8. The LED display module according to claim 7, characterized in that: The flatness of the top surface of the protective adhesive layer (40) is ±0.1 mm; and / or the roughness of the top surface of the protective adhesive layer (40) is between Ra0.4 and Ra0.

2.

9. The LED display module according to any one of claims 1 to 6, characterized in that: The LED display module further comprises a functional film layer (50) arranged above the protective adhesive layer (40).

10. An LED display device, comprising an LED display module, characterized in that: The LED display module is the LED display module according to any one of claims 1 to 9.

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