[0040] Example 1
[0041] The first embodiment of the present invention provides a backlight module 200 , for its overall structure, please refer to Figure 2a As shown, in order to express the local structure of the quantum dot display panel 200 more clearly, along the Figure 2a After the section in the middle A direction and the partial enlargement at M, please refer to Figure 2b As shown, the backlight module 200 includes: a backplane 210, a light guide plate 220 disposed at the bottom of the backplane 210, a light source 230 disposed opposite the light incident surface of the light guide plate 220, a reflection sheet 240 disposed below the light guide plate 220, and The protective layer 250 , the refraction layer 260 and the diaphragm group 270 are placed above the light guide plate 220 and laminated in sequence.
[0042] Specifically, the back plate 210 includes a bottom plate 211 and a side wall 212 perpendicular to the edge of the bottom plate 211 , and the light guide plate 220 includes a light incident surface 221 , a light exit surface 222 perpendicular to the light incident surface 221 and a lower surface opposite to the light exit surface 222 223, a plurality of concave parts 280 encapsulated with quantum dot materials 281 are arranged on the light emitting surface 222, and a protective layer 250 is attached on the light emitting surface 222 to realize the encapsulation of the quantum dot materials, so as to isolate the moisture and oxygen in the outside air, The light source 230 opposite to the light incident surface 221 and disposed on the side wall 212 is used to emit light, and the light enters the light guide plate 220 through the light incident surface 222 to excite the quantum dot material 281, which is generated by the quantum dot material 281 being excited by the light A white backlight is obtained by mixing the primary color light of the 2000 , and the film group 270 disposed opposite to the light-emitting surface 222 is used for diffusing and homogenizing the obtained white backlight.
[0043] Further, for the overall structure of the light guide plate 220, please refer to Figure 3a As shown, a plurality of concave portions 280 for encapsulating the quantum dot material 281 are provided on the light exit surface 222 of the light guide plate 220, and the partial structure thereof is as follows: Figure 3b As shown, the concave portion 280 has an arc surface and is concave in the light emitting surface 222 . Optionally, the concave portion 280 may be disposed on the light-emitting surface 222 by means of laser or thermal pressing.
[0044] Optionally, the specific structure of the concave portion 280 may further include, for example, Figure 3c Conical shape shown, such as Figure 3d shown in the rectangular shape, as well as Figure 3e As shown in the groove shape, the concave portion 280 can also be a combination of one or more of the above-mentioned various structural forms. It should be noted that the concave portion 280 for accommodating the quantum dot material 281 can have various structural forms. Other structural forms made by the recessed portion 280 also fall within the protection scope of the present invention.
[0045] Exemplarily, the quantum dot material 281 filled in the recessed portion 280 includes red quantum dot material and green quantum dot material. The quantum dot material emits red light and green light respectively under the excitation of the incident blue light. Part of the incident blue light of the unexcited quantum dot material 281 is transmitted by the recessed portion 280, and the red light and green light obtained by the excitation are different from the partially transmitted blue light. As each primary color light together constitutes a white backlight, the white backlight is supplied to the panel for displaying images after being diffused and homogenized by the diaphragm group 270 placed above.
[0046] It should be noted that the quantum dot material 281 may further include red quantum dot material, green quantum dot material and blue quantum dot material. When the light emitted by the light source 230 is violet light, the red quantum dot material, green quantum dot material and Under the excitation of violet light, the blue quantum dot material emits red, green and blue light respectively and mixes to obtain a white backlight. Different quantum dot materials are excited by light of a specific wavelength band, and a white backlight is obtained by mixing the generated light of different wavelength bands. This technology belongs to the prior art in the art, and will not be repeated here.
[0047] Since the quantum dot material 281 will fail when it encounters moisture or oxygen in the external environment, the stable output of the white backlight cannot be guaranteed. In order to prevent the quantum dot material 281 from contacting with external moisture or oxygen, the quantum dot material 281 needs to be packaged to isolate outside moisture and oxygen. Please refer to Figure 2b As shown, the protective layer 250 provided is attached to the light-emitting surface 222 and covers the plurality of recesses 280 disposed on the light-emitting surface 222 . In this way, the quantum dot material 281 consists of the recesses 280 and the protective layer covering the light-emitting surface 222 . 250 is encapsulated as a whole, which can effectively isolate moisture and oxygen from the outside world. Wherein, the material of the protective layer 250 may be Al 2 O 3 or SiO 2 , and can be prepared by depositing a thin film on the light-emitting surface 22 by magnetron sputtering or evaporation. Wherein, the material and processing technology of the protective layer 250 belong to the prior art in the field, and will not be repeated here.
[0048] In order to solve the problems of low light extraction efficiency and low light output in the protective layer 250 existing in the related art, the refraction layer 260 is laminated on the surface of the protective layer 250, and the refractive index of the refraction layer 260 is between the protective layer 250. between the air layer. Among them, the material of the protective layer 250 is selected from Al 2 O 3 or SiO 2 , its refractive index is about 1.6-1.8, and the refractive index of the outside air layer is about 1, that is, the refractive index of the refractive layer 260 is between 1-1.6. Specifically, the refractive layer 260 may deposit a layer of MgF on the lower surface of the protective layer 250 by magnetron sputtering or evaporation 2 thin films, where MgF 2 The index of refraction is about 1.38. Or the refractive layer 260 can also be made by coating a layer of optical resin material with a refractive index between 1-1.6 on the outer surface of the protective layer 250 .
[0049] It should be further noted that the material of the refractive layer 260 is not limited to the MgF proposed in this embodiment 2 and optical resin, if those skilled in the art do not make any creative work, according to the technical scheme and inventive concept of the present invention, the use of other materials with a refractive index between 1-1.6 for the refractive layer 260 also belongs to the present invention. within the scope of protection.
[0050] Since the diaphragm group 270 is stacked on the surface of the refraction layer 260, there is an air layer between the refraction layer 260 and the diaphragm group 270. When the light generated by the quantum dot material 281 under the excitation of light exits, the After passing through the protective layer 250 and the refraction layer 260, the light is injected into the outside air layer, and then the film group 270 realizes the diffusion and homogenization of the light. There are a variety of transmission media on the exit path of the light, and the light emitted by the recessed portion 280 sequentially passes through the interface between the protective layer 250 and the refractive layer 260 and the interface between the refractive layer 260 and the air layer. The refractive index of 260 is between the protective layer 250 and the air layer, so that the refractive index difference between the protective layer 250 and the air layer is decomposed into, the refractive index difference between the protective layer 250 and the refracting layer 260 and the refractive index difference between the refracting layer 260 and the refracting layer 260. The difference in the refractive index of the air layer is compared with that in the related art where light directly exits from the interface between the protective layer and the air layer with a large refractive index difference, the interface between the protective layer 250 and the refractive layer 260 in the present application, and the refraction The difference between the refractive indices of the media on both sides of the interface between the layer 260 and the air layer is small, which can reduce the number of total reflection rays at the interface of each layer, and increase the number of rays that finally enter the air layer, improving the protective layer 250. light output efficiency.
[0051] In order to further reduce the amount of total reflection light in the protective layer 250 and improve the light extraction efficiency of the light in the protective layer 250, please refer to Figure 2c As shown, a plurality of refraction layers 260 are laminated outward in sequence on the surface of the protective layer 250 , and the refractive index of each refraction layer 260 is between the protective layer 250 and the air layer, and decreases layer by layer in sequence.
[0052] It should be noted that, laminating and laminating a plurality of refractive layers 260 outwards in sequence refers to laminating and laminating a plurality of refracting layers 260 on the surface of the protective layer 250 in a direction away from the light exit surface 222. For the direction of the surface of the recessed portion 280 , that is, the direction away from the light-emitting surface 222 , please refer to Figure 2c The b direction in the graph is shown, wherein the refractive index of the refracting layers 260 laminated and laminated along the b direction decreases sequentially.
[0053] It should also be noted that, in this embodiment, when the refractive layer 260 is laminated on the surface of the protective layer 250 , there is no other medium between the refractive layer 260 and the protective layer 250 and the bonding surfaces between the protective layers 260 . The existence of layers, such as air layers and other dielectric layers. That is to say, the protective layer 250 and the refracting layer 260 or the refracting layers 260 are closely attached. Therefore, in order to realize the lamination and bonding arrangement of the refractive layer 260 , for example, the refractive layer 260 may be deposited on the bonding surface by magnetron sputtering or evaporation, or the refractive layer 260 may be coated on the bonding surface.
[0054] By laminating and adhering the multi-layered refractive layers 260 on the outer surface of the protective layer 250, the light emitted from the concave portion 280 first passes through the plurality of refractive layers 260 in sequence, and then enters the air layer. The refractive index between the two layers decreases in turn, which can further reduce the refractive index difference between the protective layer 250 and the air layer. Since the refractive index difference between the refracting layers 260 through which the light passes decreases, the total reflection at the interface between the two adjacent refracting layers 260 and the interface between the outermost refracting layer and the air layer reduces the occurrence of total reflection. The quantity of light, thereby increasing the quantity of light finally entering the air layer, improves the light extraction efficiency of the light in the protective layer 250 .
[0055] example, see Figure 2c As shown, the first refractive layer 261 is first attached to the surface of the protective layer 250. Specifically, the first refractive layer 262 is deposited on the outer surface of the protective layer 250 by magnetron sputtering or evaporation. A layer of MgF 2 thin films, where MgF 2 The index of refraction is about 1.38. The second refractive layer 262 is coated with a layer of optical resin material with a refractive index of about 1.2 on the outer surface of the first refractive layer 261 .
[0056] In this way, the light emitted from the recessed portion 280 passes through the protective layer 250 , the first refracting layer 261 and the second refracting layer 262 in sequence and then enters the air layer. Among them, two more refracting layers are arranged between the protective layer 250 and the air layer. Compared with the single refracting layer, the refractive index difference between the interfaces of each layer in the light path can be further reduced, so that the total reflection occurs between the media of each layer. The number of light rays that cannot be emitted is reduced, and the number of emitted light rays in the protective layer 250 is increased.
[0057] In this embodiment, two layers of refracting layers 260 are provided on the light-emitting surface 222 of the protective layer 250 as an example, and the materials and processing methods of the first refracting layer 261 and the second refracting layer 262 are provided in detail. illustrate. It should be further noted that, for those skilled in the art, the three-layer, four-layer or multi-layer refracting layers 260 provided according to the technical solutions and inventive concept of the present invention, and the refractive index of each layer is graded, should belong to protection scope of the present invention.
[0058]In the backlight module provided in the first embodiment, the concave portion is arranged on the light-emitting surface of the light guide plate and filled with quantum dot material, and the quantum dot material is encapsulated by the protective layer covering the light-emitting surface of the light guide plate. A refractive layer with a refractive index between the protective layer and the air layer is arranged on the exit surface of the protective layer, so as to reduce the refractive index difference between the layers of the medium on the exit path from the protective layer to the air, and reduce the difference in the refractive index between the adjacent two layers. The amount of light that is totally reflected between the media, thereby increasing the amount of light emitted from the protective layer to the outside. On the basis of ensuring the reliability of the quantum dot material, it reduces the amount of light that is totally reflected when the protective layer directly enters the air layer. , to improve the output quantity of light in the quantum dots and the light output efficiency of the white backlight in the backlight module, so as to meet the needs of users for high color gamut display images.
