Backlight module and display device
By setting a white blue light source and a light chromaticity conversion film on the edge of the lamp board, combining the reflector and prism sheet, the problem of blue light leakage at the edge of the blue light Mini Led backlight module is solved, reducing blue light leakage and preventing yellowing, achieving More even light output.
Patent Information
- Application Number
- CN202420407969.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-04
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-03-04
AI Technical Summary
The existing blue light Mini Led backlight module has blue light leakage at the edge of the diaphragm, and the edge failure of the QD film will aggravate the blue edge. Existing improvement solutions such as the use of black tape or phosphor will cause other problems, such as dark tape on the black edge. Or yellowing.
A second light source is arranged at the edge of the lamp plate, the second light source surrounds the first light source for emitting white blue light, and converting blue light into white light through a light chromaticity conversion film, combining the reflector plate and the prism sheet to reduce blue light leakage, and through Quantum dot region and fluorescent region prevent yellowing.
It effectively reduces the blue light content at the edge of the lamp board, avoids the blue light leakage at the edge of the backlight module, prevents the picture from being blue, and avoids the white light leakage problem, and improves the edge light utilization efficiency of the display device.
Smart Images
Figure CN222213156U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of displays, in particular to a backlight module and a display device. Background Art
[0002] With the development of display technology, thin and light display panels are very popular among consumers, especially thin and light display panels (liquid crystal display, LCD). An existing display device includes a thin film transistor array substrate (Thin Film Transistor Array Substrate, TFT Array Substrate), a color filter substrate (Color Filter Substrate, CF Substrate) and liquid crystal molecules filled between the thin film transistor array substrate and the color filter substrate. When the above display device is working, a driving voltage is applied to the pixel electrode of the thin film transistor array substrate and the common electrode of the color filter substrate respectively, or a driving voltage is applied to the common electrode and the pixel electrode of the thin film transistor array substrate respectively, to control the rotation direction of the liquid crystal molecules between the two substrates, so as to refract the backlight provided by the backlight module of the display device, thereby displaying a picture.
[0003] At present, Mini LED technology is becoming more and more popular in the market, especially for high-end cars, which prefer to use Mini Led technology on the central control. At present, there are two main types of Mini Led backlight modules, one uses blue light Mini Led, which needs to be used with QD film (quantum dot film) or fluorescent film; the other uses white light Mini Led. Since white light Mini Led uses lamp bead packaging, it is more expensive than blue light. Therefore, the use of blue light Mini Led has more advantages in cost, but the blue light Mini Led with QD film will leak blue light at the edge of the film, and the QD film is prone to edge failure in reliability, which will aggravate the blue edge phenomenon.
[0004] In the existing blue light Mini Led backlight module technology, in order to prevent blue light from leaking from the edge of the film and not aggravate the blue edge phenomenon when the edge of the QD film fails, there are mainly the following ways to improve the blue edge:
[0005] (a) Sticking black tape on the edge of the diffuser plate. Although the black tape can prevent some blue light from leaking out, it will cause black edge and dark band phenomenon; (b) Applying phosphor on the edge of the diffuser plate. Although the phosphor can combine with blue light to convert into white light to prevent some blue light from leaking out, it will cause yellowing of the edge of the film after passing through the QD film; (c) Increasing the size of the corresponding prism sheet. Due to the limitation of the frame and the expansion space of the film, the improvement of the blue edge is slight. Utility Model Content
[0006] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a backlight module and a display device to solve the problem of blue light leakage at the edge of the diaphragm of the blue light Mini Led backlight module in the prior art.
[0007] The purpose of the utility model is achieved through the following technical solutions:
[0008] The utility model provides a backlight module, including a lamp board and a light chromaticity conversion film located on the light emitting side of the lamp board, wherein a first light source and a second light source located on the edge of the lamp board are arranged on the lamp board, wherein the second light source surrounds the periphery of the first light source, the first light source is used for emitting blue light, the second light source is used for emitting white-bluish light, and the light chromaticity conversion film is used for converting the blue light into white light.
[0009] Furthermore, a reflective plate is provided at the edge of the light board, and a receiving groove is formed between the reflective plate and the light board, and the second light source is arranged in the receiving groove.
[0010] Furthermore, the number of the accommodating slots is the same as the number of the second light sources, and each of the accommodating slots is provided with the second light source.
[0011] Furthermore, the second light source comprises an upper light source group, a left light source group, a lower light source group and a right light source group, and the blue light chromaticity of the second light sources in the upper light source group, the left light source group, the lower light source group and the right light source group presents a gradual change from one end to the other.
[0012] Furthermore, the blue light chromaticity of the second light source in the upper light source group gradually increases from the right end to the left end, the blue light chromaticity of the second light source in the left column light source group gradually increases from the upper end to the lower end, the blue light chromaticity of the second light source in the lower light source group gradually increases from the left end to the right end, and the blue light chromaticity of the second light source in the right column light source group gradually increases from the lower end to the upper end.
[0013] Furthermore, the light chromaticity conversion film includes a quantum dot region and a fluorescent region located at an edge of the light chromaticity conversion film, the quantum dot region corresponds to a distribution region of the first light source, and the fluorescent region corresponds to a distribution region of the second light source.
[0014] Furthermore, the backlight module includes a diffusion plate, a beam splitter film and a diffusion film, the diffusion plate is arranged between the light board and the light chromaticity conversion film, and the beam splitter film and the diffusion film are both arranged on a side of the light chromaticity conversion film away from the diffusion plate.
[0015] Furthermore, the backlight module includes a first prism sheet and a second prism sheet which are stacked on each other, and the first prism sheet and the second prism sheet are both arranged on a side of the light chromaticity conversion film away from the diffusion plate.
[0016] Furthermore, the backlight module comprises a brightness enhancement film, and the brightness enhancement film is arranged on a side of the light chromaticity conversion film away from the diffusion plate.
[0017] The present application also provides a display device, comprising a liquid crystal display panel and the backlight module as described above, wherein the liquid crystal display panel is arranged on the light emitting side of the backlight module.
[0018] The beneficial effects of the utility model are as follows: by arranging a second light source for emitting white light with a bluish tint at the edge of the lamp board, the second light source surrounds the periphery of the first light source emitting blue light, thereby reducing the blue light content at the edge of the lamp board, and reducing the phenomenon of blue light leakage at the edge of the backlight module, thereby avoiding the problem of the picture being bluish at the edge of the display device; and white light is light that can be used by the display device, and there is basically no problem of white light leakage at the edge of the display device. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of the backlight module in the utility model;
[0020] Figure 2 It is a schematic diagram of the planar structure of the light board in the utility model;
[0021] Figure 3 It is a schematic diagram of the planar structure of the light chromaticity conversion film in the utility model;
[0022] Figure 4 It is a structural schematic diagram of the display device in the utility model. DETAILED DESCRIPTION
[0023] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the present invention, the specific implementation methods, structures, features and effects of the backlight module and display device proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments:
[0024] Figure 1 It is a structural schematic diagram of the backlight module in the utility model. Figure 2 It is a schematic diagram of the planar structure of the light board in the utility model. Figure 3 It is a schematic diagram of the planar structure of the light chromaticity conversion film in the utility model.
[0025] like Figures 1 to 3As shown, a backlight module 10 provided in the first embodiment of the utility model includes a lamp board 11 and a light chromaticity conversion film 13 located on the light emitting side of the lamp board 11. The lamp board 11 is provided with a first light source 111 and a second light source 112 located at the edge of the lamp board 11. The second light source 112 surrounds the periphery of the first light source 111. The first light source 111 is used to emit blue light, and the second light source 112 is used to emit white-blue light (i.e., white light is blue). The light chromaticity conversion film 13 is used to convert blue light into white light. Among them, the first light source 111 is a Mini Led that can emit blue light, and the second light source 112 is a Mini Led that can emit white-blue light. The Mini Led is packaged on the lamp board 11 by dispensing glue, and the lamp board 11 has a driving circuit to drive the first light source 111 and the second light source 112 to emit light.
[0026] The utility model arranges a second light source 112 for emitting white light with a bluish tint at the edge of the lamp board 11, and the second light source 112 surrounds the periphery of the first light source 111 emitting blue light, thereby reducing the blue light content at the edge of the lamp board 11 and alleviating the phenomenon of blue light leakage at the edge of the backlight module 10, thereby avoiding the problem of the picture being bluish at the edge of the display device; white light is light that can be used by the display device, and there is basically no white light leakage problem at the edge of the display device.
[0027] Furthermore, a reflective plate 113 is provided at the edge of the lamp board 11, and a receiving groove is formed between the reflective plate 113 and the lamp board 11, and the second light source 112 is arranged in the receiving groove. The large-angle light emitted by the second light source 112 will be repeatedly reflected by the side wall of the receiving groove, thereby reducing the angle of the light emitted by the second light source 112, that is, the reflective plate 113 has a focusing effect on the light emitted by the second light source 112, so as to further reduce the phenomenon of blue light leakage at the edge of the backlight module 10; at the same time, it can also prevent the interference between the white-bluish light and the blue light at the lamp board 11, which is conducive to solving the problem of crosstalk between the two lights. Among them, the number of receiving grooves is the same as the number of the second light sources 112, and the second light source 112 is arranged in each receiving groove, thereby increasing the focusing effect of the reflective plate 113 on the light emitted by the second light source 112.
[0028] Furthermore, the second light source 112 includes an upper light source group 112a, a left light source group 112b, a lower light source group 112c, and a right light source group 112d, which together form a rectangular frame surrounding the edge of the light board 11, and the blue light chromaticity of the second light source 112 in the upper light source group 112a, the left light source group 112b, the lower light source group 112c, and the right light source group 112d shows a gradual change from one end to the other. The second light source 112 uses a Mini Led that can emit white light and white-bluish light, thereby preventing pure white light and blue light from interfering with each other, causing the blue at the junction of the lights to be lighter, and causing the picture to be yellowish.
[0029] In this embodiment, the chromaticity of the blue light of the second light source 112 in the upper light source group 112a gradually increases from the right end to the left end, the chromaticity of the blue light of the second light source 112 in the left light source group 112b gradually increases from the upper end to the lower end, the chromaticity of the blue light of the second light source 112 in the lower light source group 112c gradually increases from the left end to the right end, and the chromaticity of the blue light of the second light source 112 in the right light source group 112d gradually increases from the lower end to the upper end. For example, in the upper light source group 112a, the second light source 112 at the right end is a white-blue light Mini Led with low chromaticity, and the other second light sources 112 are white-blue light Mini Led with higher chromaticity, and the closer to the left end, the higher the chromaticity of the blue light; in the left column light source group 112b, the second light source 112 at the upper end is a white-blue light Mini Led with low chromaticity, and the other second light sources 112 are white-blue light Mini Led with higher chromaticity, and the closer to the lower end, the higher the chromaticity of the blue light; in the lower light source group 112c, the second light source 112 at the left end is a white-blue light Mini Led with low chromaticity, and the other second light sources 112 are white-blue light Mini Led with higher chromaticity, and the closer to the right end, the higher the chromaticity of the blue light; in the right column light source group 112d, the second light source 112 at the lower end is a white-blue light Mini Led with low chromaticity, and the other second light sources 112 are white-blue light Mini Led with higher chromaticity. Of course, in other embodiments, the chromaticity of the blue light of the second light source 112 in the upper light source group 112a gradually increases from the left end to the right end, the chromaticity of the blue light of the second light source 112 in the left column light source group 112b gradually increases from the bottom end to the top end, the chromaticity of the blue light of the second light source 112 in the lower light source group 112c gradually increases from the right end to the left end, and the chromaticity of the blue light of the second light source 112 in the right column light source group 112d gradually increases from the top end to the bottom end.
[0030] In this embodiment, the light chromaticity conversion film 13 includes a quantum dot area 131 and a fluorescent area 132 located at the edge of the light chromaticity conversion film 13. The quantum dot area 131 corresponds to the distribution area of the first light source 111, and the fluorescent area 132 corresponds to the distribution area of the second light source 112. Among them, the quantum dot area 131 is filled with quantum dots, and the fluorescent area 132 is composed of polymer UV glue and fluorescent powder. Both quantum dots and fluorescent powder can convert blue light into white light. By filling the edge of the light chromaticity conversion film 13 with polymer UV glue and fluorescent powder, the blue tint of white light is not affected; at the same time, the influence of the edge quantum dot failure on the chromaticity can also be avoided, and the light of the chromaticity gradient Mini Led is prevented from yellowing when passing through the edge of the light chromaticity conversion film 13.
[0031] Among them, quantum dots (QDs) are usually nanoparticles composed of II-Vl or III-V elements, with a size smaller than or close to the exciton Bohr radius (generally no more than 10nm in diameter), and have obvious quantum effects. It is generally considered to be a quasi-zero-dimensional material, a semiconductor nanostructure that binds conduction band electrons, valence band holes and excitons in three spatial directions.
[0032] When the particle size of nanomaterials drops to a certain value (generally below 10nm), the electron energy levels near the metal Fermi level change from quasi-continuous to discrete levels, and the energy gap between the discontinuous highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels of nano-semiconductor particles becomes wider, causing the absorption and fluorescence peaks to blue shift. This phenomenon is called the quantum size effect.
[0033] The quantum size effect has caused a huge change in the photoelectric properties of semiconductor quantum dots. When the size of semiconductor quantum dot particles is smaller than the Bohr radius of the exciton, the quantum size effect produced changes the energy level structure of the semiconductor material, transforming it from a continuous energy band structure to a discrete energy level structure with molecular characteristics. This phenomenon can be used to prepare semiconductor quantum dots of different particle sizes in the same reaction, produce light emissions of different frequencies, and thus can easily control a variety of luminescent colors. The energy of the solid absorbed photons (absorption) will be greater than the radiated photons (luminescence), so the luminescence spectrum will shift to the lower energy direction (redshift) compared with the absorption spectrum, and the difference between the two photon energies is called the Stokes Shift.
[0034] In this embodiment, the backlight module 10 includes a diffusion plate 12, a bezel 14 and a diffusion film 15. The diffusion plate 12 is disposed between the light board 11 and the light chromaticity conversion film 13. The bezel 14 and the diffusion film 15 are both disposed on the side of the light chromaticity conversion film 13 away from the diffusion plate 12. Optionally, the bezel 14 is disposed between the light chromaticity conversion film 13 and the diffusion film 15. The diffusion plate 12, the bezel 14 and the diffusion film 15 are all used to homogenize the light, so that the light emitted by the backlight module 10 is more uniform.
[0035] Further, the backlight module 10 includes a first prism sheet 161 and a second prism sheet 162 which are stacked on each other, and the first prism sheet 161 and the second prism sheet 162 are both arranged on a side of the light chromaticity conversion film 13 away from the diffusion plate 12. Optionally, the first prism sheet 161 and the second prism sheet 162 are both arranged on a side of the diffusion film 15 away from the light chromaticity conversion film 13, so that the first prism sheet 161 and the second prism sheet 162 converge the light, so that the light emitted by the backlight module 10 is collimated light.
[0036] Furthermore, the backlight module 10 includes a brightness enhancement film 17 , which is disposed on a side of the light chromaticity conversion film 13 away from the diffusion plate 12 , and is used to increase the brightness of light passing through the brightness enhancement film 17 .
[0037] The backlight module 10 further includes a back plate 18 having a mounting groove therein, wherein the lamp panel 11 , the diffusion plate 12 , the light chromaticity conversion film 13 , the beam splitter film 14 , the diffusion film 15 , the first prism sheet 161 , the second prism sheet 162 and the brightness enhancement film 17 are all mounted in the mounting groove.
[0038] Figure 4 It is a schematic diagram of the structure of the display device in the utility model. Figure 4 As shown, this embodiment further provides a display device, including a liquid crystal display panel and the backlight module 10 as described above, wherein the liquid crystal display panel is disposed on the light emitting side of the backlight module 10 .
[0039] The liquid crystal display panel includes an array substrate 20, a color filter substrate 30 disposed opposite to the array substrate 20, and a liquid crystal layer 40 located between the array substrate and the color filter substrate 30. The liquid crystal layer 40 uses positive liquid crystal molecules, that is, liquid crystal molecules with positive dielectric anisotropy. In the initial state, the positive liquid crystal molecules in the liquid crystal layer 40 are aligned parallel to the color filter substrate 30 and the array substrate, and the alignment direction of the positive liquid crystal molecules close to the color filter substrate 30 is antiparallel to the positive liquid crystal molecules close to the array substrate. Of course, in other embodiments, the liquid crystal layer 40 may also use negative liquid crystal molecules, and the negative liquid crystal molecules in the liquid crystal layer 40 may be aligned perpendicular to the color filter substrate 30 and the array substrate 20, that is, similar to the alignment mode of the VA display mode.
[0040] On the color filter substrate 30, a plurality of color resist layers 32 corresponding to the pixel units and a black matrix (BM) 31 for separating the plurality of color resist layers 32 from each other are provided on the side facing the liquid crystal layer 40. A black matrix 31 is provided between any two adjacent columns and rows of pixel units. The color resist layer 32 includes red (R), green (G), and blue (B) color resist materials, which correspond to forming red, green, and blue pixel units, respectively. The black matrix 31 is located between the red, green, and blue pixel units, so that adjacent pixel units are separated from each other by the black matrix 31.
[0041] On the side of the array substrate 20 facing the liquid crystal layer 40, a plurality of scanning lines (not shown) and a plurality of data lines (not shown) are insulated and cross-defined to form a plurality of pixel units. A pixel electrode 22 and a thin film transistor (not shown) are provided in each pixel unit. The pixel electrode 22 is electrically connected to the data line of the adjacent thin film transistor through the thin film transistor. The thin film transistor includes a gate, an active layer, a drain electrode and a source electrode. The gate electrode and the scanning line are located in the same layer and are electrically connected. The gate electrode and the active layer are separated by an insulating layer. The source electrode is electrically connected to the data line, and the drain electrode is electrically connected to the pixel electrode 22 through a contact hole. The common electrode 21 and the pixel electrode 22 can be made of transparent conductive materials such as indium tin oxide (ITO) and indium zinc oxide (IZO).
[0042] like Figure 4 As shown, the common electrode 21 and the pixel electrode 22 are located in different layers and insulated and isolated by an insulating layer. The common electrode 21 can be located above or below the pixel electrode 22. Preferably, the common electrode 21 is a planar electrode arranged on the entire surface, and the pixel electrode 22 is a block electrode arranged in an integral block in each pixel unit or a slit electrode having a plurality of electrode strips to form a fringe field switching mode (Fringe Field Switching, FFS). Of course, the pixel electrode 22 and the common electrode 21 can also be located in the same layer, but the two are insulated and isolated from each other, and the pixel electrode 22 and the common electrode 21 can each include a plurality of electrode strips, and the electrode strips of the pixel electrode 22 and the electrode strips of the common electrode 21 are arranged alternately with each other to form an in-plane switching mode (In-Plane Switching, IPS). Of course, the common electrode 21 can also be arranged on the color filter substrate 30 to form a VA display mode or a TN display mode.
[0043] An upper polarizer 51 is disposed on the side of the color filter substrate 30 away from the liquid crystal layer 40 , and a lower polarizer 52 is disposed on the side of the array substrate away from the liquid crystal layer 40 . The light transmission axis of the upper polarizer 51 is perpendicular to the light transmission axis of the lower polarizer 52 .
[0044] In this document, the directional words such as up, down, left, right, front, and back are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application. It should also be understood that the terms "first" and "second" used in this document are only used to distinguish names and are not used to limit quantity and order.
[0045] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the protection scope of the technical solution of the present invention.
Claims
1. A backlight module, characterized in that: The invention comprises a light board (11) and a light chromaticity conversion film (13) located on the light emitting side of the light board (11); the light board (11) is provided with a first light source (111) and a second light source (112) located at the edge of the light board (11); the second light source (112) surrounds the periphery of the first light source (111); the first light source (111) is used to emit blue light; the second light source (112) is used to emit white-bluish light; and the light chromaticity conversion film (13) is used to convert blue light into white light.
2. The backlight module according to claim 1, characterized in that: A reflective plate (113) is provided at the edge of the lamp board (11), the reflective plate (113) and the lamp board (11) form a receiving groove, and the second light source (112) is arranged in the receiving groove.
3. The backlight module according to claim 2, characterized in that: The number of the accommodating grooves is the same as the number of the second light sources (112), and each of the accommodating grooves is provided with the second light source (112).
4. The backlight module according to claim 1, characterized in that: The second light source (112) comprises an upper light source group (112a), a left light source group (112b), a lower light source group (112c) and a right light source group (112d); the blue light chromaticity of the second light sources (112) in the upper light source group (112a), the left light source group (112b), the lower light source group (112c) and the right light source group (112d) presents a gradual change from one end to the other.
5. The backlight module according to claim 4, characterized in that: The chromaticity of blue light of the second light source (112) in the upper light source group (112a) gradually increases from the right end to the left end, the chromaticity of blue light of the second light source (112) in the left light source group (112b) gradually increases from the top end to the bottom end, the chromaticity of blue light of the second light source (112) in the lower light source group (112c) gradually increases from the left end to the right end, and the chromaticity of blue light of the second light source (112) in the right light source group (112d) gradually increases from the bottom end to the top end.
6. The backlight module according to any one of claims 1 to 5, characterized in that: The light chromaticity conversion film (13) comprises a quantum dot region (131) and a fluorescent region (132) located at the edge of the light chromaticity conversion film (13), the quantum dot region (131) corresponding to the distribution region of the first light source (111), and the fluorescent region (132) corresponding to the distribution region of the second light source (112).
7. The backlight module according to any one of claims 1 to 5, characterized in that: The backlight module (10) comprises a diffusion plate (12), a beam splitter film (14) and a diffusion film (15); the diffusion plate (12) is arranged between the light board (11) and the light chromaticity conversion film (13); the beam splitter film (14) and the diffusion film (15) are both arranged on a side of the light chromaticity conversion film (13) away from the diffusion plate (12).
8. The backlight module according to claim 7, characterized in that: The backlight module (10) comprises a first prism sheet (161) and a second prism sheet (162) which are stacked on each other, and the first prism sheet (161) and the second prism sheet (162) are both arranged on a side of the light chromaticity conversion film (13) away from the diffusion plate (12).
9. The backlight module according to claim 7, characterized in that: The backlight module (10) comprises a brightness enhancement film (17), and the brightness enhancement film (17) is arranged on a side of the light chromaticity conversion film (13) away from the diffusion plate (12).
10. A display device, characterized in that: It comprises a liquid crystal display panel and a backlight module (10) as described in any one of claims 1 to 9, wherein the liquid crystal display panel is arranged on the light emitting side of the backlight module (10).