Light source structure, backlight module and display device

Abstract

The present invention relates to a light source structure, a backlight module, and a display device. The light source structure includes a substrate, a plurality of light-emitting units, and an encapsulation body. The plurality of light-emitting units are arrayed on the substrate. The encapsulation body covers the light-emitting units. A plurality of recessed structures are provided on the light-emitting surface of the encapsulation body. These recessed structures correspond one-to-one to the light-emitting units, and each recessed structure is recessed toward its corresponding light-emitting unit to form a light-emitting surface. The light-emitting surface is a light-collecting surface.

Description

Technical Field

[0001] The present invention relates to a light source element, and in particular to a light source structure, a backlight module and a display device. Background Art

[0002] A typical direct-lit backlight module mainly utilizes a plurality of light emitting diode arrays and employs a secondary lens or an optical film design to mix the light generated by adjacent light emitting diodes, thereby forming a surface light source with uniform light.

[0003] Currently, there's a backlight system using Mini LEDs. Mini LEDs are smaller than traditional LEDs, allowing them to be combined with local dimming technology to achieve more refined control of the light source, enhancing display quality. Due to Mini LEDs' smaller size, their number and arrangement density need to be significantly increased. To achieve local dimming with densely packed Mini LEDs, the light generated by adjacent LEDs must minimize interference. Therefore, improving the quality and refined control of local dimming has become a major goal for relevant industry players. Summary of the Invention

[0004] Therefore, the purpose of the present disclosure is to provide a light source structure, a backlight module and a display device, which can generate a directional light emission effect through the light source structure, so that when the light source structure is applied to the backlight module or the display device, the local dimming effect can be enhanced.

[0005] In accordance with the aforementioned objectives of the present disclosure, a light source structure is provided. This light source structure includes a substrate, a plurality of light-emitting units, and an encapsulation body. The plurality of light-emitting units are arrayed on the substrate. The encapsulation body covers the light-emitting units. A light-emitting surface of the encapsulation body is provided with a plurality of recessed structures. These recessed structures correspond one-to-one to the light-emitting units, and each recessed structure is recessed toward its corresponding light-emitting unit to form a light-emitting surface. The light-emitting surface is a light-collecting surface.

[0006] According to an embodiment of the present disclosure, each of the above-mentioned recessed structures has a depth D, the package body has a thickness T, and each of the light-emitting units has a height H. The depth D, thickness T, and height H satisfy a first relationship: D <T-H。

[0007] According to an embodiment of the present disclosure, the light emitting surface of each of the recessed structures is a curved surface, and the recessed structure has a width W. The ratio of the width W to the depth D falls between 1 and 4, inclusive.

[0008] According to an embodiment of the present disclosure, the ratio of the width W to the depth D of each of the above-mentioned recessed structures is 2.

[0009] According to an embodiment of the present disclosure, the light angle of each light emitting unit after passing through the corresponding recessed structure is 70% of the original light angle of the light emitting unit.

[0010] According to an embodiment of the present disclosure, the package body is integrally covered on the light-emitting unit.

[0011] According to an embodiment of the present disclosure, the light-emitting surface of each of the light-emitting units is completely in contact with the package body.

[0012] According to an embodiment of the present disclosure, the width W of the recessed structure is at least half of the side length of the light emitting unit, and the light emitting surfaces of adjacent recessed structures do not contact each other.

[0013] In accordance with the above-mentioned purpose of the present disclosure, a backlight module is provided. The backlight module includes the aforementioned light source structure and at least one optical film. The optical film is disposed above the light source structure.

[0014] In accordance with the above-mentioned objectives of the present disclosure, a display device is provided. The display device includes the aforementioned light source structure, at least one optical film, and a display panel. The optical film is disposed above the light source structure. The display panel is disposed above the optical film.

[0015] As can be seen from the above, the present invention primarily utilizes recessed structures corresponding to the light-emitting units in the package of the light-emitting units. This recessed structure then utilizes the light-collecting surface of the recessed structure to create a focused optical effect as the light generated by the light-emitting units passes through the recessed structure. As a result, the light generated by each light-emitting unit does not affect the light generated by its neighboring light-emitting units, thereby achieving the goal of precisely controlling the brightness and color of each pixel block in the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the above and other objects, features, advantages and embodiments of the present invention more clearly understood, the following drawings are provided:

[0017] Figure 1 is a schematic diagram illustrating a display device according to one embodiment of the present invention;

[0018] Figure 2 FIG2 is a schematic diagram illustrating light emitted by a light emitting unit of a light source structure according to an embodiment of the present invention and passing through a recessed structure on a package body;

[0019] Figure 3 is a diagram illustrating a light emission effect simulated by using recessed structures with different ratios of width to depth according to one embodiment of the present invention; and

[0020] Figure 4 FIG. 1 is a diagram illustrating a light extraction effect simulated by using recessed structures of different sizes with the same width-to-depth ratio according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] Please refer to Figure 1 , which is a schematic diagram illustrating a display device according to one embodiment of the present invention. The display device 100 of this embodiment primarily includes a backlight module 200 and a display panel 300. The backlight module 200 includes a light source structure 210 and at least one optical film 220. The optical film 220 is disposed above the light source structure 210, and the display panel 300 is disposed above the optical film 220. Thus, light generated by the light source structure 210 can pass through the optical film 220 before exiting the display panel 300.

[0022] Please continue to refer to Figure 1 The light source structure 210 includes a substrate 211, a plurality of light-emitting units 212, and a package 213. The plurality of light-emitting units 212 are arrayed on the substrate 211. The package 213 covers the light-emitting units 212. In this embodiment, the light source structure 210 uses a mini LED backlight or a micro LED backlight, and the package 213 integrally covers the light-emitting units 212, and the light-emitting surface of each light-emitting unit 212 completely contacts the package 213. In one example, the package 213 can be an integral structure formed by coating optical adhesive on the light-emitting unit 212.

[0023] like Figure 1 As shown, a plurality of recessed structures 213a are provided on the light-emitting surface S1 of the package body 213. These recessed structures 213a correspond one-to-one to the light-emitting units 212, and each recessed structure 213a is recessed toward the corresponding light-emitting unit 212 to form a light-emitting surface S11. In this embodiment, the light-emitting surface S11 of the recessed structure 213a is a focusing surface, which is a smooth surface without any microstructures. The present invention can improve the light directivity of each light-emitting unit 212 by utilizing the focusing effect of the recessed structure 213a, and the light generated by each light-emitting unit 212 will not affect the light generated by its adjacent light-emitting unit 212, thereby achieving the effect of accurately controlling the brightness and color of each pixel block of the display panel.

[0024] Please refer to Figure 2, which is a schematic diagram illustrating the light emission of light emitted by the light-emitting unit of the light source structure according to one embodiment of the present invention through the recessed structure on the package. Preferably, the ratio of the width of the recessed structure 213a of the present invention to the side length of the corresponding light-emitting unit 212 falls between 0.5 and 1.4, and includes the end value, so that most of the light from the light-emitting unit 212 can be directed to the corresponding recessed structure 213a, thereby achieving a focusing effect. For example, the light-emitting unit 212 of one embodiment of the present invention can use an LED with front-emitting light, such as an LED light source that can generate a light field that conforms to the Lambertian light field. Among them, the recessed structure 213a of one embodiment of the present invention has a width W, a depth D and a curvature radius r, wherein the curvature radius r can be a constant or a non-constant value. The curvature radius r of the recessed structure 213a of one embodiment of the present invention is a constant value, so that its cross-sectional shape can conform to the definition of a semicircle. However, the cross-sectional shape of the recessed structure 213a of the present invention is not limited to a semicircular shape, as long as the recessed structure 213a has a light-gathering property. In addition, in the present invention, the light angle of each light emitting unit 212 after passing through the corresponding recessed structure 213a is less than 70% of the original light angle of the light emitting unit 212. Figure 2 As shown, the light emitted by the light-emitting unit 212 of this embodiment has an optical opening angle of approximately 120 degrees. However, when the light passes through the recessed structure 213a, it is refracted by the recessed structure 213a and converged to emit light with an optical opening angle of less than 80 degrees. Therefore, after passing through its corresponding recessed structure 213a, the light emitted by each light-emitting unit 212 is concentrated by the recessed structure 213a, producing a focusing effect. Therefore, when each light-emitting unit 212 corresponds to a pixel block of the display panel 300, the light emitted by adjacent light-emitting units 212 does not interfere with each other, thereby enabling precise control of the brightness and color of each pixel block of the display panel 300.

[0025] Please refer again Figure 1, the encapsulation body 213 has a thickness T, and each light-emitting unit 212 has a height H. Among them, the depth D of each recessed structure 213a, the thickness T of the encapsulation body 213, and the height H of the light-emitting unit 212 satisfy the first relational expression: D < T - H. Preferably, in an embodiment of the present invention, the cross-sectional shape of the light-emitting surface S11 of the recessed structure 213a is an arc surface, and the depth D and the width W of the recessed structure 213a satisfy the second relational expression: 1 ≤ W / D ≤ 4. In other words, the ratio of the width W to the depth D of the recessed structure 213a falls between 1 and 4, and includes the end values. When the ratio of the width W to the depth D of the recessed structure 213a of the present invention exceeds 4, the radian of the recessed structure 213a is not obvious enough, resulting in a poor light-concentrating effect; when the ratio of the width W to the depth D of the recessed structure 213a of the present invention is less than 1, the recessed structure 213a is in the shape of a deep hole, thereby confining the light emitted by the light-emitting unit 212 to the bottom of the recessed structure 213a, resulting in the generation of the hot spot phenomenon.

[0026] In an embodiment, the width W of the recessed structure 213a of the present invention is at least half of the side length of the light-emitting unit 212, so that the light with the first 50% intensity emitted from the light-emitting unit 212 can fall within the range covered by the light-emitting surface S11 of the recessed structure 213a, thereby ensuring that the light emitted from the light-emitting unit 212 can be concentrated. Generally speaking, if the width W of the recessed structure is less than half of the side length of the light-emitting unit 212, the effect of not being able to concentrate light may occur. Furthermore, in a preferred example, the light-emitting surfaces S11 of adjacent recessed structures 213a do not contact each other to ensure that the light-emitting uniformity of the overall light-emitting surface S1 is not affected. That is to say, once the adjacent recessed structures 213a overlap each other, it may affect the light-emitting effect of the respective light-emitting surfaces S11 corresponding to the adjacent recessed structures 213a.

[0027] Please refer to Figure 1 、 Figure 3 , in which Figure 3 is a light-emitting effect diagram simulated by using recessed structures with different width-to-depth ratios according to an embodiment of the present invention. As Figure 3As shown, in Comparative Example 1, the full width at half maximum (FWHM) generated by light passing through a package without a recessed structure is approximately 0.6 mm. In Examples A through D, the curvature radius r of the recessed structures of Examples A through D is constant. The full width at half maximum (FWHM) generated by light passing through the recessed structures of Examples A and B is 0.4 mm, indicating that the light is more concentrated and has better directivity. Furthermore, the luminance curves show that the luminance generated by Examples A and B is significantly higher than that of Comparative Example 1. This indicates that when the ratio of the width W to the depth D of the recessed structure 213a is between 2 and 3 (inclusive), the light is more concentrated, has higher luminance, and exhibits better directivity. Furthermore, in Example C, when the ratio of the width W to the depth D of the recessed structure 213a is 4, although the FWHM of the light generated is similar to that of Comparative Example 1, the luminance generated by Example C is higher than that of Comparative Example 1. This indicates that the design of the recessed structure 213a can improve the overall brightness of the light output. Regarding Example D, the half-width (WHM) and brightness of the light passing through the recessed structure of Example D are similar to those of Comparative Example 1. Therefore, when the ratio of the width W to the depth D of the recessed structure 213a is 10, there is no effect of improving the half-width (WHM) and brightness.

[0028] Please also refer to Figure 1 and Figure 4 ,in Figure 4 FIG. 1 is a diagram showing the light emission effect simulated by using recessed structures with the same width-to-depth ratio but different sizes according to one embodiment of the present invention. Figure 4As shown, the recessed structure 213a of Comparative Example 2 is in the shape of an elongated hole. Therefore, the light emitting surface S11 of Comparative Example 2 is further away from the light emitting surface S1 than that of Example A. This causes the light emitted by the corresponding light emitting unit 212 to be confined by the recessed structure 213a in the shape of an elongated hole. As a result, the brightness difference between the light emitting surface S11 of the recessed structure 213a and the light emitting surface S1 becomes more obvious, resulting in a hot spot phenomenon. The overall luminance of the light emitting surface S1 is reduced, resulting in a poor overall optical effect of the backlight module. In Examples E, F, and G, the side length of the light emitting unit in Examples E, F, and G is 200 μm, and the ratio of the width W to the depth D of the recessed structure 213a is 2. The ratios of the width W of the recessed structure 213a to the side length of the corresponding light emitting unit 212 in Examples E, F, and G are 0.5, 1, 1.3, and 1.4, respectively. It can be seen that when the ratio of the width W of the recessed structure 213a to the side length of the light-emitting unit falls between 0.5 and 1.4 (including the end points), the light emitted by the corresponding light-emitting unit 212 can all be focused by the recessed structure 213a, thereby improving the light directionality of each light-emitting unit 212, and the light generated by each light-emitting unit will not affect the light generated by its adjacent light-emitting unit, thereby achieving the effect of accurately controlling the brightness and color of each pixel block of the display panel.

[0029] As can be seen from the aforementioned embodiments of the present invention, the present invention primarily utilizes recessed structures corresponding to the light-emitting units in the package of the light-emitting units. This recessed structure then utilizes the light-collecting surface of the recessed structure to create an optical effect of focusing the light generated by the light-emitting units as it passes through the recessed structure. As a result, the light generated by each light-emitting unit does not affect the light generated by its neighboring light-emitting units, thereby achieving the goal of precisely controlling the brightness and color of each pixel block in the display panel.

[0030] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the patent application of the present invention should fall within the scope of the present invention.

[0031] Reference Signs List

[0032] 100: Display device

[0033] 200: Backlight module

[0034] 210: Light source structure

[0035] 211: Substrate

[0036] 212: Light-emitting unit

[0037] 213: Encapsulation

[0038] 213a: Depression structure

[0039] 220: Optical film

[0040] 300: Display panel

[0041] D: Depth

[0042] H: Height

[0043] r: radius of curvature

[0044] S1: light-emitting surface

[0045] S11: Light exiting surface

[0046] T: thickness

[0047] W: width.

Claims

1. A light source structure, characterized in that: Include: substrate; a plurality of light-emitting units arrayed on the substrate; and a package body covering the plurality of light-emitting units, wherein a plurality of recessed structures are provided on a light-emitting surface of the package body, the plurality of recessed structures corresponding one-to-one to the plurality of light-emitting units, and each of the plurality of recessed structures is recessed toward the corresponding light-emitting unit to form a light-emitting surface, wherein the light-emitting surface is a curved surface; The light emitting surface is a light-collecting surface, so that the light generated by each light-emitting unit does not affect the light generated by its adjacent light-emitting unit; Each of the plurality of recessed structures has a depth D and a width W; The package body has a thickness T; and Each of the plurality of light emitting units has a height H; Wherein, the depth D, the thickness T and the height H satisfy the first relationship: D <T-H; The ratio of the width W to the depth D falls between 2 and 4, including endpoint values.

2. The light source structure according to claim 1, characterized in that: A ratio of the width W to the depth D of each of the plurality of recessed structures is 2.

3. The light source structure according to claim 1, characterized in that: The light angle of the light emitted by each of the plurality of light emitting units after passing through the corresponding recessed structure is less than 70% of the original light angle of each of the plurality of light emitting units.

4. The light source structure according to claim 1, characterized in that: The package body integrally covers the plurality of light emitting units.

5. The light source structure according to claim 1, characterized in that: A light emitting surface of each of the plurality of light emitting units completely contacts the package body.

6. The light source structure according to claim 1, characterized in that: A width W of each of the plurality of recessed structures is at least half of a side length of the light emitting unit, and light emitting surfaces of adjacent recessed structures do not contact each other.

7. A backlight module, characterized in that: Include: The light source structure according to any one of claims 1 to 6; and At least one optical film is disposed above the light source structure.

8. A display device, characterized in that: Include: The light source structure according to any one of claims 1 to 6; at least one optical film, which is disposed above the light source structure; and The display panel is arranged above the at least one optical film.

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