Light-emitting device

Abstract

A light-emitting device comprises a substrate, a plurality of light-emitting elements and a light-guiding structure. The light-emitting elements are arranged on the substrate. The light-guiding structure is arranged on the substrate, the light-guiding structure separates the light-emitting elements and continuously surrounds the light-emitting elements, the light-guiding structure and the light-emitting elements are separated from each other, the light emitted by the light-emitting elements can enter the light-guiding structure to make the light-guiding structure emit light, and the light-guiding structure is made of a material with a refractive index of 1.1 to 3. The light-guiding structure of the present invention can greatly reduce the number of light-emitting diodes and adopt a thinner diffusion structure while still maintaining good brightness uniformity of the light-emitting device.

Description

Technical Field

[0001] The invention relates to a light emitting device including a light guiding structure. Background Art

[0002] Displays that cannot emit light by themselves can use backlight modules to obtain light supply. Generally speaking, backlight modules can be divided into edge type and direct type.

[0003] For direct-type backlight modules, a diffuser is provided on the LED array to reduce the phenomenon of uneven brightness (Mura) when the display is displayed. To improve the phenomenon of uneven brightness, it is also possible to consider increasing the number of LEDs or increasing the optical distance (OD). However, increasing the number of LEDs will increase the material cost and manufacturing cost. Increasing the optical distance will make the backlight module thicker, which is not conducive to the thinning of the backlight module.

[0004] Therefore, how to improve the brightness unevenness without increasing the number of light emitting diodes and the optical distance has become an urgent issue to be solved in the art. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a light emitting device, which can appropriately reflect, refract and transmit the light emitted by the light emitting diode through a special light guide structure, thereby improving the brightness unevenness without increasing the number of light emitting diodes and increasing the optical distance. The light guide structure of the present invention can even greatly reduce the number of light emitting diodes while still maintaining good brightness uniformity of the light emitting device.

[0006] The light-emitting device provided by the present invention comprises a substrate, a plurality of light-emitting elements and a light-guiding structure. The light-emitting elements are arranged on the substrate. The light-guiding structure is arranged on the substrate, the light-guiding structure separates the light-emitting elements and continuously surrounds the light-emitting elements, the light-guiding structure and the light-emitting elements are separated from each other, the light emitted by the light-emitting elements can enter the light-guiding structure to make the light-guiding structure emit light, and the light-guiding structure is made of a material with a refractive index of 1.1 to 3.

[0007] According to some embodiments of the present invention, the material includes silicone, poly(methyl methacrylate) (PMMA), epoxy resin, glass, quartz, inorganic particles or a combination thereof.

[0008] According to some embodiments of the present invention, the inorganic particles are selected from the group consisting of aluminum oxide, barium sulfate, magnesium oxide, zirconium oxide and silicon oxide.

[0009] According to some embodiments of the present invention, the light emitting device further comprises a diffusion structure disposed on the light emitting element, the light guide structure and the substrate, and the diffusion structure contacts the light guide structure.

[0010] According to some embodiments of the present invention, the width of the light-guiding structure between two adjacent light-emitting elements is greater than the distance between the light-guiding structure and one of the two adjacent light-emitting elements.

[0011] According to some embodiments of the present invention, a ratio of the width to the distance is greater than or equal to 3.

[0012] According to some embodiments of the present invention, the light emitting device further includes a packaging material filled between the light guide structure and the light emitting element, and the packaging material is made of another material with a refractive index greater than or equal to 1.1 and less than 1.6.

[0013] According to some embodiments of the present invention, the light guide structure includes a plurality of light guide units, each of which continuously surrounds one of the light emitting elements.

[0014] According to some embodiments of the present invention, the visible light transmittance of the light guiding structure is greater than the visible light reflectivity of the light guiding structure.

[0015] According to some embodiments of the present invention, the material is a translucent material.

[0016] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention may be more fully understood by reading the following detailed description of embodiments and referring to the accompanying drawings:

[0018] Figure 1 is a top view schematic diagram of a light emitting device according to some embodiments of the present invention;

[0019] Figure 2 is a cross-sectional schematic diagram of a light emitting device according to some embodiments of the present invention;

[0020] Figure 3 is a cross-sectional schematic diagram of a light emitting device according to some embodiments of the present invention;

[0021] Figure 4 A photographic image of a light-emitting device according to an example of the present invention in which the light-emitting element does not emit light, the light-emitting device comprising a light-emitting element and a light-guiding structure;

[0022] Figure 5 for Figure 4 A photographic image of a light-emitting device when the light-emitting element emits light;

[0023] Figure 6A photographic image of a light-emitting device according to an example of the present invention when a light-emitting element emits light, the light-emitting device comprising a light-emitting element, a light-guiding structure and a diffusion structure;

[0024] Figure 7 A photographic image of a light-emitting device when a light-emitting element according to an example of the present invention emits light, the light-emitting device comprising a light-emitting element, a light-guiding structure, a diffusion structure and a quantum dot film;

[0025] Figure 8 for Figure 7 The light-emitting device produces a charge coupled device (CCD) luminance and chromaticity image when the light-emitting element emits light.

[0026]

Explanation of symbols

[0027] 10: Light-emitting device

[0028] 110:Substrate

[0029] 120: Light emitting element

[0030] 130: Light guide structure

[0031] 130a: light guide unit

[0032] 140: Diffusion structure

[0033] 150: Packaging material

[0034] D1: Distance

[0035] H1, H2: Height

[0036] OD: Optical distance

[0037] W1: Width DETAILED DESCRIPTION

[0038] In order to make the description of the present invention more detailed and complete, the following is an illustrative description of the implementation and specific embodiments of the present invention; however, this is not the only form of implementing or using the specific embodiments of the present invention. The embodiments disclosed below can be combined or replaced with each other in beneficial circumstances, and other embodiments can be added to one embodiment without further explanation. In the following description, many specific details will be described in detail to enable the reader to fully understand the following embodiments. However, the embodiments of the present invention can be practiced without these specific details.

[0039] In addition, spatially relative terms, such as "below" and "above", are used to facilitate the description of the relative relationship between one element or feature and another element or feature in the drawings. The true meaning of these spatially relative terms includes other orientations. For example, when the drawings are flipped 180 degrees up and down, the relationship between one element and another element may change from "below" to "above". The spatially relative descriptions used in this article should also be interpreted in the same way.

[0040] As described above, the present invention provides a light-emitting device, which can appropriately partially reflect, partially refract, and partially penetrate the light emitted by the light-emitting diode through a special light-guiding structure, thereby improving the phenomenon of uneven brightness without increasing the number of light-emitting diodes and increasing the optical distance. It is worth noting that the light-guiding structure of the present invention can even enable the light-emitting device to maintain good brightness uniformity when the number of light-emitting diodes is greatly reduced. Several embodiments of the light-emitting device of the present invention will be described in detail below.

[0041] Figure 1 Schematic top view of a light emitting device according to some embodiments of the present invention. Figure 2 Schematic cross-sectional view of a light emitting device according to some embodiments of the present invention. Figure 1 and Figure 2 As shown, the light emitting device 10 includes a substrate 110 , a plurality of light emitting elements 120 and a light guide structure 130 .

[0042] like Figure 2 As shown, the light emitting element 120 is disposed on the substrate 110. In some embodiments, the light emitting element 120 contacts the substrate 110. In some embodiments, the light emitting element 120 is a light emitting diode.

[0043] like Figure 2 As shown, the light guide structure 130 is disposed on the substrate 110. In some embodiments, the light guide structure 130 contacts the substrate 110. Figure 2 As shown, the light guide structure 130 itself does not emit light, but the light energy emitted by the light emitting element 120 first passes through the gas medium (such as air, with a refractive index of 1) and then refracts into the light guide structure 130, causing the light guide structure 130 to emit light. Therefore, the brightness uniformity of the light emitting device 10 can be effectively improved to avoid the occurrence of uneven brightness.

[0044] In some embodiments, the wavelength of the light emitted by the light guide structure 130 is similar to the wavelength of the light emitted by the light emitting element, and the wavelength difference between the two is less than or equal to 10 nanometers.

[0045] The light guide structure 130 is made of a material with a refractive index of 1.1 to 3, for example, a material with a refractive index of 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0. In some embodiments, the light guide structure 130 is made of a material with a refractive index of 1.5 to 3. In some embodiments, the light guide structure 130 is made of a material with a refractive index greater than 1.5 and less than or equal to 3. In some embodiments, the visible light transmittance of the light guide structure 130 is greater than the visible light reflectance of the light guide structure 130.

[0046] In some embodiments, the material of the light guide structure 130 is a translucent material. In some embodiments, the material of the light guide structure 130 includes silicone, polymethylmethacrylate (PMMA), epoxy resin, glass, quartz, inorganic particles or a combination thereof. In some embodiments, the inorganic particles are selected from the group consisting of aluminum oxide, barium sulfate, magnesium oxide, zirconium oxide and silicon oxide.

[0047] like Figure 1 As shown, the light guide structure 130 is in a grid shape, which separates a plurality of light emitting elements 120 and continuously surrounds the light emitting elements 120. The light guide structure 130 and the light emitting elements 120 are separated from each other and do not contact each other. In some embodiments, the light guide structure 130 includes a plurality of light guide units 130a, each of which continuously surrounds one of the light emitting elements 120. In some embodiments, as Figure 1 As shown, the light guide unit 130a is square, but in other embodiments, the light guide unit 130a may also be other shapes, such as polygonal (e.g., quadrilateral, pentagon, hexagon, etc.), circular, elliptical, etc., as long as the light guide unit 130 can continuously surround the light emitting element 120.

[0048] In some embodiments, Figure 2 As shown, the light emitting device 10 further includes a diffusion structure 140 disposed on the light emitting element 120, the light guide structure 130 and the substrate 110. In some embodiments, the diffusion structure 140 contacts the top of the light guide structure 130. In some embodiments, the diffusion structure 140 includes one or more diffusion plates and one or more diffusion sheets stacked on each other to help improve the brightness uniformity of the light emitting device.

[0049] In some embodiments, Figure 2As shown, the width W1 of the light guide structure 130 between two adjacent light emitting elements 120 is greater than the distance D1 between the light guide structure 130 and one of the two adjacent light emitting elements 120. In some embodiments, the ratio of the width W1 to the distance D1 is greater than or equal to 3, or even greater than or equal to 4 or greater than or equal to 5.

[0050] In some embodiments, Figure 2 As shown, the height H1 of the light guide structure 130 is greater than the height H2 of the light emitting element 120. In some embodiments, the ratio of the height H1 to the height H2 is greater than or equal to 1.5, or even greater than or equal to 2 or greater than or equal to 3.

[0051] In some embodiments, Figure 2 As shown, the optical distance OD of the light emitting device 10 is the same as the height H1 of the light guide structure 130. In some embodiments, the optical distance OD is between 0.3 mm and 3 mm, for example, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm or 2 mm.

[0052] Figure 3 Schematic cross-sectional view of a light emitting device according to some embodiments of the present invention. Figure 3 and Figure 2 The difference is that Figure 3 The light emitting device 10 further includes a packaging material 150, which is filled between the light guide structure 130 and the light emitting element 120. The packaging material 150 is made of another material with a refractive index greater than or equal to 1.1 and less than 1.6, for example, a material with a refractive index of 1.1, 1.2, 1.3, 1.4, 1.5 or 1.55. Figure 3 As shown, the light emitted by the light emitting element 120 passes through the packaging material 150 and then refracts into the light guide structure 130 , so that the light guide structure 130 emits light.

[0053] Figure 4 This is a photographic image of a light-emitting device according to an example of the present invention, in which the light-emitting element is not emitting light. The light-emitting device includes a light-emitting element and a light-guiding structure. Figure 4 As shown, the light-guiding structure itself does not emit light.

[0054] Figure 5 for Figure 4 The photographic image of the light-emitting device when the light-emitting element emits light. Figure 5 As shown, when the light-emitting element emits light, the light enters the light-guiding structure, causing the light-guiding structure to emit light.

[0055] Figure 6The photographic image of the light-emitting device when the light-emitting element according to one example of the present invention emits light is shown. The light-emitting device includes a light-emitting element, a light-guiding structure and a diffusion structure. Figure 6 The light emitting device is Figure 4 The light emitting device is equipped with a diffusion structure. Figure 6 As shown, there is no obvious brightness unevenness in the light-emitting area of ​​the light-emitting device, and its brightness uniformity is good.

[0056] Figure 7 The photographic image of the light-emitting device when the light-emitting element according to one example of the present invention emits light, the light-emitting device includes a light-emitting element, a light-guiding structure, a diffusion structure and a quantum dot film (QD film). Figure 7 The light emitting device is Figure 6 The light-emitting device is equipped with a quantum dot film. Figure 7 As shown, there is no obvious brightness unevenness in the light-emitting area of ​​the light-emitting device, and its brightness uniformity is good.

[0057] Figure 8 for Figure 7 The charge coupled device (CCD) brightness and color image of the light-emitting device when the light-emitting element emits light. Figure 8 As shown, there is no obvious brightness unevenness in the light-emitting area of ​​the light-emitting device, and its brightness uniformity is good.

[0058] The following experimental examples are used to describe the specific aspects of the present invention in detail and enable those with ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. However, the following experimental examples are not used to limit the present invention.

[0059] The light-emitting devices of Comparative Examples 1 to 6 include a plurality of light-emitting elements and a diffusion structure, but do not include a light-guiding structure; the light-emitting devices of Experimental Examples 1 to 3 include a plurality of light-emitting elements, a light-guiding structure and a diffusion structure.

[0060] The spacing of the light emitting elements, the types of diffusion structures used, the presence or absence of the light guide structure, and the brightness uniformity of the light emitting devices after testing in Comparative Examples 1 to 6 and Experimental Examples 1 to 3 are listed in Table 1. It should be noted that the thickness of the diffusion structure 1 is 400 to 500 microns thicker than the thickness of the diffusion structure 2. The thickness of the diffusion structure 2 is 400 to 500 microns thicker than the thickness of the diffusion structure 3 and the thickness of the diffusion structure 4.

[0061] Table 1

[0062]

[0063]

[0064] When the spacing between light emitting elements is smaller, the total number of light emitting elements used is greater; when the spacing between light emitting elements is larger, the total number of light emitting elements used is less. In Comparative Examples 1 to 6 and Experimental Examples 1 to 3, the total number of light emitting elements with a spacing of 5 microns is about 36% less than the total number of light emitting elements with a spacing of 4 microns.

[0065] Referring to Table 1, compared with Comparative Example 1 having a thicker diffusion structure 1 and a larger total number of light-emitting elements (the spacing between the light-emitting elements is 4 microns), the brightness uniformity of the light-emitting devices of Comparative Examples 2 to 6 having thinner diffusion structures 2, 3 or 4 and a smaller total number of light-emitting elements (the spacing between the light-emitting elements is 5 microns) is significantly reduced by about 4 to 7%.

[0066] Continuing to refer to Table 1, however, compared to Comparative Example 1, the light-emitting devices of Experimental Examples 1 to 3, which have thinner diffusion structures 2, 3 or 4 and a smaller total number of light-emitting elements (the spacing between light-emitting elements is 5 microns), do not significantly reduce the brightness uniformity of the light-emitting devices due to the special light-guiding structure of the present invention. It can be seen that the light-guiding structure of the present invention can greatly reduce the number of light-emitting diodes and use a thinner diffusion structure while still allowing the light-emitting device to maintain good brightness uniformity. Therefore, the use of the light-guiding structure of the present invention can significantly reduce the material and manufacturing costs of the light-emitting device.

[0067] Although the present invention has been described in considerable detail with reference to embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

[0068] It is obvious that, for those skilled in the art, various modifications and changes can be made to the structure of the present invention without departing from the scope or spirit of the present invention. In view of the foregoing, the present invention is intended to cover modifications and changes of the present invention as long as they fall within the scope of the appended claims.

Claims

1. A light emitting device, characterized in that: include: a substrate; A plurality of light emitting elements are disposed on the substrate; a light guide structure, directly disposed on the substrate, the light guide structure separates the plurality of light emitting elements and continuously surrounds the plurality of light emitting elements, the light guide structure and the plurality of light emitting elements are separated from each other, the light emitted by the plurality of light emitting elements can enter the light guide structure to make the light guide structure emit light, the light guide structure is made of a material with a refractive index of 1.1 to 3, a material of the light guide structure is a translucent material, and the visible light transmittance of the light guide structure is greater than the visible light reflectance of the light guide structure; as well as A diffusion structure is disposed on the plurality of light-emitting elements, the light-guiding structure and the substrate.

2. The light emitting device according to claim 1, characterized in that: The material includes silicone, poly(methyl methacrylate) (PMMA), epoxy resin, glass, quartz, inorganic particles or a combination thereof.

3. The light emitting device according to claim 2, characterized in that: The inorganic particles are selected from the group consisting of aluminum oxide, barium sulfate, magnesium oxide, zirconium oxide and silicon oxide.

4. The light emitting device according to claim 1, characterized in that: The diffusion structure contacts the light guiding structure.

5. The light emitting device according to claim 1, characterized in that: A width of the light-guiding structure between two adjacent light-emitting elements is greater than a distance between the light-guiding structure and one of the two adjacent light-emitting elements.

6. The light emitting device according to claim 5, characterized in that: A ratio of the width to the distance is greater than or equal to 3.

7. The light emitting device according to claim 1, characterized in that: It also includes a packaging material filled between the light-guiding structure and the plurality of light-emitting elements, and the packaging material is made of another material with a refractive index greater than or equal to 1.1 and less than 1.

6.

8. The light emitting device according to claim 1, characterized in that: The light guide structure includes a plurality of light guide units, each of which continuously surrounds one of the plurality of light emitting elements.

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