A multi-layered light emitting device and backlight module

Abstract

The present invention discloses a light-emitting device with a multi-layer structure and a backlight module, wherein the light-emitting device with a multi-layer structure includes a frame, a chip, a reflective layer and a package; the chip is installed at the bottom of the frame, the reflective layer is arranged in the frame and is located above the chip, the package is filled in the frame and the chip and the reflective layer are packaged and fixed, a bottom plate is laid at the bottom of the frame, a reflective coating is arranged on the top surface of the bottom plate, the reflective surface of the reflective layer and the reflective coating are both facing the chip, and the light emitted by the chip is diffusely reflected to increase the light output angle. The backlight module includes an LED light board and an optical film; the LED light board is composed of a plurality of light-emitting devices, a plurality of connectors and a substrate, any light-emitting device is a light-emitting device of the multi-layer structure mentioned above, a plurality of light-emitting devices are installed on the substrate through a plurality of connectors, and the optical film is mounted above the substrate for light distribution processing of the light emitted by the LED light board. No optical lens is required for secondary light distribution and the cost can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of backlight display, and in particular relates to a light-emitting device with a multi-layer structure and a backlight module. Background Art

[0002] With the advancement of technology, LCD TVs are also developing towards thinner sizes. Existing LCD TVs mainly use direct-type backlight modules or backlight modules without optical lenses as the backlight source of the LCD panel.

[0003] The direct-type backlight module is composed of a substrate (printed circuit board), a light-emitting device, an optical lens, and a diffusion plate stacked from bottom to top. The optical lens performs secondary light distribution processing on the light emitted by the light-emitting device to increase the light output angle, so that each backlight module of the LCD TV emits light evenly and improves the overall display effect. The shape, size and other parameters of the optical lens are determined according to the model standard of the backlight module, so that each model of backlight module requires a specially customized optical lens. This causes problems such as poor adaptability and high production cost of the optical lens, which limits the market and development of the optical lens and even the backlight module.

[0004] In addition, the matching accuracy requirements between the light-emitting device and the optical lens are extremely high, and high-precision equipment is needed for assembly, which makes the assembly cost high and difficult to control.

[0005] However, the existing backlight module without optical lens needs to increase the number of light emitting devices per unit area to make up for the uniformity of light, which also causes the problem of high and difficult to control production costs.

[0006] In summary, there is an urgent need for a light emitting device that can increase the light output angle without the need for secondary light distribution using an optical lens, so that the assembly cost and manufacturing cost of a backlight module using the light emitting device can be significantly reduced, thereby improving market competitiveness. Summary of the invention

[0007] The object of the present invention is to provide a light emitting device with a multi-layer structure, which can diffuse light through the multi-layer structure and increase the light output angle without the need for secondary light distribution through an optical lens.

[0008] The present invention is achieved through the following technical solutions:

[0009] A multi-layered light emitting device comprises a frame, a chip, a reflective layer and a package; the chip is mounted on the bottom of the frame, the reflective layer is arranged in the frame and is located above the chip, the package is filled in the frame and packages and fixes the chip and the reflective layer, a bottom plate is laid at the bottom of the frame, a reflective coating is arranged on the top surface of the bottom plate, the reflective surfaces of the reflective layer and the reflective coating are both facing the chip, and the light emitted by the chip is diffusely reflected to increase the light output angle.

[0010] Through the above scheme, the present invention at least achieves the following technical effects:

[0011] The light emitting device in the existing direct-type backlight module does not diffuse the light emitted by the chip, so an optical lens is required for secondary light distribution. The multi-layer light emitting device of the present invention adds multiple layers of refraction, diffuse reflection and reflection structures inside itself, diffuses the light emitted by the chip before outputting it outward, and realizes that the multi-layer structure light emitting device does not need secondary light distribution of optical lenses and still has the effect of a large light output angle.

[0012] The multi-layer structure light emitting device of the present invention diffuses the light emitted by the chip. The main structure is a diffuse reflection combination composed of a reflective layer and a reflective coating. The light emitted by the light is diffusely reflected by the reflective layer and then projected onto the reflective coating. According to the imaging principle, the area of ​​the light spot formed on the reflective coating is larger than the area of ​​the chip as the light source, which has the effect of enlarging the size of the light source. The light spot of the mirror image on the reflective coating continues to reflect the light toward the package and then passes through the package to the outside world. Compared with the light emitted by the chip directly passing through the package to the outside world, the light output angle is significantly increased.

[0013] Preferably, the encapsulation body is composed of a positioning layer and a refractive layer; the bottom surface of the refractive layer is connected to the top surface of the positioning layer, and the top of the refractive layer protrudes from the top surface of the frame.

[0014] Preferably, the bottom surface of the refractive layer and the top surface of the positioning layer are attached to each other to form an arc-shaped dielectric interface concave toward the chip.

[0015] Preferably, the reflective layer is arranged between the positioning layer and the refractive layer; the reflective surface of the reflective layer is an arc-shaped surface protruding toward the chip and is arranged to fit the surface of the positioning layer.

[0016] Preferably, the reflective layer and the chip are both centrosymmetric structures, and their center lines coincide with each other; and the orthographic projection area of ​​the reflective layer is greater than or equal to the orthographic projection area of ​​the chip.

[0017] Preferably, the reflective layer is arranged in contact with the chip; the reflective layer has the same shape and area as the chip.

[0018] Preferably, fluorescent powder or diffusion particles may be added to the refractive layer.

[0019] Another object of the present invention is to provide a backlight module, which uses the multi-layer structure light-emitting device in the above solution to reduce assembly cost and manufacturing cost and improve market competitiveness.

[0020] The present invention is achieved through the following technical solutions:

[0021] A backlight module includes an LED light board and an optical film; the LED light board is composed of a plurality of light-emitting devices, a plurality of connectors and a substrate, any of the light-emitting devices is a light-emitting device of the multi-layer structure described in the above scheme, the plurality of light-emitting devices are installed on the substrate through a plurality of connectors, and the optical film is mounted above the substrate for performing light distribution processing on the light emitted by the LED light board.

[0022] Through the above scheme, the present invention at least achieves the following technical effects:

[0023] Compared with the existing direct-type backlight module, the backlight module of the present invention does not need an optical lens for secondary light distribution, thus saving the process and equipment for assembling the backlight module and the optical lens and reducing the assembly cost.

[0024] Compared with the existing backlight module without optical lens, each light emitting device in the backlight module of the present invention can perform light diffusion processing inside itself, so that the number of light emitting devices arranged in a unit area of ​​the backlight module is smaller and the manufacturing cost is lower.

[0025] Preferably, the optical film includes one or a laminated combination of a diffusion film, a white light conversion film or a brightness enhancement film.

[0026] Preferably, the distance between the surface of the LED light panel and the lower surface of the optical film is 1-20 mm.

[0027] The beneficial effects of the present invention are:

[0028] By setting a reflective layer and a reflective coating inside the light emitting device, the light emitted by the chip is reflected and refracted multiple times and then emitted at a wider angle, thereby increasing the light output angle of the light emitting device. No optical lens is required for secondary light distribution, thus saving the cost of assembling optical lenses. In particular, by forming an arc-shaped dielectric interface in the package body, the number of refractions of light when passing through the package body is increased, further increasing the light output angle of the light emitting device. The backlight module using this type of light emitting device has fewer such light emitting devices per unit area, and the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a schematic cross-sectional structure diagram of a multi-layer light-emitting device provided in one embodiment of the present invention.

[0030] Figure 2 It is a schematic cross-sectional structure diagram of a light-emitting device in which a reflective layer is bonded to a chip provided in one embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the cross-sectional structure of a light-emitting device with added phosphor or diffusion particles provided in one embodiment of the present invention.

[0032] Figure 4 The figure is a schematic cross-sectional structure diagram of a backlight module provided in one embodiment of the present invention.

[0033] Figure 5 The figure is a schematic top view of the structure of an LED light board in a backlight module provided in one embodiment of the present invention.

[0034] legend:

[0035] 1 frame; 2 chip; 3 reflective layer; 4 package; 5 LED light board; 6 optical film;

[0036] 11 bottom plate; 12 reflective coating;

[0037] 41 positioning layer; 42 refraction layer;

[0038] 51 light emitting device; 52 connector; 53 substrate;

[0039] 61 diffusion film; 62 white light conversion film; 63 brightness enhancement film. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] Embodiment 1:

[0042] like Figure 1 As shown, this embodiment provides a multi-layered light emitting device consisting of a frame 1 , a chip 2 , a reflective layer 3 and a packaging body 4 .

[0043] The frame 1 is in a groove structure as a whole, with a bottom plate 11 laid at the bottom, and a reflective coating 12 coated on the top surface of the bottom plate 11. The chip 2 is installed on the reflective coating 12 as a light source, and a reflective layer 3 is arranged above the chip 2, with the reflective surface of the reflective layer 3 facing the chip 2. At this time, the reflective surface of the reflective layer 3 is opposite to the reflective surface of the reflective coating 12. Then, the packaging glue is injected into the groove structure of the frame 1 and solidified to form a packaging body 4, and the chip 2, the reflective layer 3 and the frame 1 are packaged and fixed.

[0044] It is worth mentioning that the reflective layer 3 is a semi-reflective film or a silica gel layer containing a reflective filler such as TiO2, so that part of the light emitted by the chip 2 can directly pass through the reflective layer 3, and the other part is reflected by the reflective layer 3 to avoid the appearance of dark shadows.

[0045] The light emitted by the chip 2 is partially reflected by the reflective layer 3 and irradiates the reflective coating 12 on the top surface of the bottom plate 11. At this time, the imaging spot area of ​​the reflective surface of the reflective coating 12 is larger than the area of ​​the chip 2, which has the effect of magnifying the light source area. The light continues to be reflected by the reflective surface of the reflective coating 12 and irradiates the package 4. The package 4 is made of a transparent packaging glue material, and the light can pass through it. In the process of passing through, it encounters the medium interface between the air and the package 4 and refracts, further expanding the light output angle. It replaces the effect of secondary light distribution of optical lenses.

[0046] In this embodiment, the bottom plate is made of copper, and the reflective coating is a silver-plated layer on the surface of the copper bottom plate. The reflective coating can also be replaced by a thin sheet structure or a film structure that also has the function of reflecting light.

[0047] Embodiment 2:

[0048] like Figure 1 As shown, based on Example 1, this embodiment further optimizes the structure of the package body 4 and the reflective layer 3, so that the package body 4 can provide more refracted light times, while enhancing the diffuse reflection effect of the reflective layer 3 and increasing the imaging spot area on the reflective surface of the reflective coating 12.

[0049] The package body 4 is composed of two main parts, namely the positioning layer 41 and the refractive layer 42. The positioning layer 41 is made of pure packaging glue solidified, and its main function is to package and fix the chip 2, the reflective layer 3 and the frame 1, and at the same time allow the light to pass through and refract the light; the refractive layer 42 is supported by silica gel, and its top is hemispherical and protrudes from the top surface of the frame 1, so that the medium interface between the refractive layer 42 and the air is spherical, increasing the refraction angle of the light. And the part protruding from the top surface of the frame 1 can also expand the angle of light emission, further enhancing the diffusion effect of light. The top shape of the refractive layer 42 can be replaced according to product requirements, including prism, cone, table and other forms.

[0050] The joint part of the positioning layer 41 and the refractive layer 42 is the medium interface of different media, and the light will also be refracted when passing through the medium interface. In order to make the light passing through the medium interface converge to the hemispherical part protruding from the top surface of the frame 1 and emit a wider emission angle, the medium interface between the positioning layer 41 and the refractive layer 42 is set to be an arc surface concave toward the chip 2.

[0051] On this basis, the reflective layer 3 is attached to the top surface of the positioning layer 41 and arranged in the concave arc surface, so that the reflective surface of the reflective layer 3 is a convex arc surface facing the chip 2, which can increase the reflection angle of the light irradiated on the convex arc surface, enhance the diffuse reflection effect of the reflective surface on the light emitted from the chip 2, and further increase the light spot area of ​​the image on the reflective surface of the reflective coating 12. Enlarging the light spot area means increasing the area and diffusion angle of the final output light.

[0052] In order to make the reflective layer 3 evenly reflect the light emitted by the chip 2 and avoid the phenomenon of one side being brighter and the other side being darker, the chip 2 and the reflective layer 3 need to be set to a centrally symmetrical structure, and the center lines of the two coincide, so that the light diffusely reflected by the reflective layer 3 is uniform in the circumferential direction.

[0053] In order to ensure that the double reflections of the reflective layer 3 and the reflective coating 12 can achieve the effect of enlarging the light source area, it is necessary to ensure that the area of ​​the reflective layer 3 is greater than or equal to the area of ​​the chip 2, so that a complete chip 2 light source spot can be presented on the reflective surface of the reflective coating 12.

[0054] like Figure 3 As shown, it is worth mentioning that in order to further enhance the light diffusion effect, light processing components such as fluorescent powder or diffusion particles can be added to the refractive layer 42 to form more medium interfaces to increase the number of light refractions and optimize the light diffusion effect. The proportion of light processing components such as added fluorescent powder and diffusion particles can be increased or decreased according to product requirements.

[0055] Embodiment 3:

[0056] The packaging position of the reflective layer 3 in the light-emitting device can be adjusted according to different standards of the product model. This embodiment, while retaining other structures of Embodiment 2 unchanged, provides a solution for packaging the reflective layer 3 directly onto the chip 2, and adaptively adjusts the shape of the reflective layer 3 to enhance the adaptability of the light-emitting device.

[0057] like Figure 2 As shown, the shape and area of ​​the reflective layer 3 are the same as those of the top surface of the chip 2, and the reflective layer 3 is directly attached to the top surface of the chip 2, and then the positioning layer 41 encapsulates and fixes the two in the frame 1. The diffuse reflection effect of the reflective layer 3 of this packaging structure is weakened, and the imaging magnification effect of the reflective surface of the reflective coating 12 is simultaneously weakened. However, it will significantly improve the uniformity of the light emitted by the light-emitting device and improve the overall display quality.

[0058] Embodiment 4:

[0059] like Figure 4 and Figure 5 As shown, this embodiment provides a backlight module, which is composed of two parts: an LED light board 5 and an optical film 6.

[0060] The LED light board 5 mainly includes a substrate 53, a plurality of connectors 52 and a plurality of light emitting devices 51, wherein the light emitting devices 51 are the light emitting devices 51 of the multilayer structure of Embodiment 1, Embodiment 2 or Embodiment 3. Each light emitting device 51 matches a connector 52 for establishing electrical connection with the substrate 53.

[0061] The optical film 6 plays the role of reprocessing the light emitted by the light emitting device 51. The optical film 6 can be any one of the diffusion film 61, the white light conversion film 62 or the brightness enhancement film 63, or multiple film stacks can be selected and used at the same time. The optical film 6 is mounted above the substrate 53. The distance from the bottom surface of the optical film 6 to the top surface of the substrate 53 of the LED light board 5 is the light mixing distance. In this embodiment, the light mixing distance can be adjusted between 1-20mm to adjust the processing effect of the optical film 6 on the diffused light emitted by the light emitting device 51, so that the light output by the backlight module is more uniform.

[0062] The various technical features in the above implementation modes can be combined arbitrarily as long as there is no conflict or contradiction between the combinations of features. However, due to space limitations, they are not described one by one.

[0063] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A multi-layer light emitting device, characterized in that: The invention comprises a frame, a chip, a reflective layer and a packaging body; the chip is installed at the bottom of the frame, the reflective layer is arranged in the frame and above the chip, the reflective layer is a semi-reflective film or a silica gel layer containing a reflective filler such as TiO2; the packaging body is composed of a positioning layer and a refractive layer, the bottom surface of the refractive layer and the top surface of the positioning layer are bonded to each other to form an arc-shaped medium interface concave to the chip; the packaging body is filled in the frame and the chip and the reflective layer are packaged and fixed, the bottom of the frame is paved with a bottom plate, the top surface of the bottom plate is provided with a reflective coating, the reflective surfaces of the reflective layer and the reflective coating are both facing the chip, and the light emitted by the chip is diffusely reflected to increase the light output angle; the reflective layer and the chip are both centrally symmetrical structures, and the center lines of the two coincide; and the orthographic projection area of ​​the reflective layer is greater than or equal to the orthographic projection area of ​​the chip.

2. The multi-layered light emitting device according to claim 1, characterized in that: The bottom surface of the refraction layer is connected to the top surface of the positioning layer, and the top of the refraction layer protrudes from the top surface of the frame.

3. The multi-layered light emitting device according to claim 2, characterized in that: The reflective layer is arranged between the positioning layer and the refractive layer; the reflective surface of the reflective layer is an arc-shaped surface protruding toward the chip and is arranged in contact with the surface of the positioning layer.

4. The multi-layered light emitting device according to claim 2, characterized in that: The reflective layer is arranged in contact with the chip; the reflective layer has the same shape and area as the chip.

5. The multi-layered light emitting device according to claim 1, characterized in that: Phosphor or diffusion particles may be added to the refractive layer.

6. A backlight module, characterized in that: It includes an LED light board and an optical film; the LED light board is composed of a plurality of light-emitting devices, a plurality of connectors and a substrate, any light-emitting device is a light-emitting device of the multi-layer structure described in any one of claims 1-5, the plurality of light-emitting devices are installed on the substrate through a plurality of connectors, and the optical film is mounted above the substrate for performing light distribution processing on the light emitted by the LED light board.

7. The backlight module according to claim 6, characterized in that: The optical film includes one or a laminated combination of a diffusion film, a white light conversion film or a brightness enhancement film.

8. The backlight module according to claim 6, characterized in that: The distance between the surface of the LED light board and the lower surface of the optical film is 1-20 mm.

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