Backlight module for improving bright line and display screen

Abstract

The utility model relates to a backlight module with improved bright line and display screen, wherein the backlight module with improved bright line comprises a back plate, a rubber frame, a light guide plate and a reflector plate, the rubber frame is connected with the inner peripheral side of the back plate, the light guide plate and the reflector plate are embedded in the rubber frame, a lamp bead assembly is arranged between one side of the rubber frame and the light guide plate, and the light guide plate is connected with the rubber frame. The reflector plate is located between the light guide plate and the back plate, and a gap is formed between the side edge of the reflector plate and the inner circumferential side of the rubber frame. The display device has the advantages of being capable of improving the display contrast ratio, simple in structure and low in cost.

Description

Technical Field

[0001] This utility model relates to the field of backlight module technology, specifically to a backlight module and display screen that improves brightness lines. Background Technology

[0002] In traditional edge-lit backlight modules, light enters from the side of the light guide plate (LGP), undergoes total internal reflection within the LGP, and is scattered across the entire display area. However, due to the high light density at the edge of the LGP and the fact that the reflector and the frame are usually tightly fitted, some light escapes from the edge after multiple reflections on the inner wall of the frame, forming obvious bright lines around the edges, which is especially noticeable in narrow bezel designs. Utility Model Content

[0003] The purpose of this invention is to provide a backlight module and display screen that can improve display contrast, has a simple structure, and is low in cost, thus improving brightness lines.

[0004] A backlight module for improving brightness lines includes a back plate, a frame, a light guide plate, and a reflector. The frame is connected to the inner periphery of the back plate. The light guide plate and the reflector are embedded in the frame. An LED assembly is disposed between one side of the frame and the light guide plate. The reflector is located between the light guide plate and the back plate, and a gap is formed between the side of the reflector and the inner periphery of the frame.

[0005] In the above solution, a certain gap is reserved between the side of the reflective sheet and the inner periphery of the frame. This can disrupt the total internal reflection path of light between the frame and the reflective sheet. The gap design allows some of the light escaping from the edge of the light guide plate to be absorbed by the back plate, and some to be scattered by the reflective sheet to the effective display area. This balances the brightness between the edge and the center, improves bright lines, especially for backlight modules with narrow bezel frames. After reducing edge light leakage, the black purity in dark conditions is higher, which is particularly effective in HDR or high contrast scenes. Only a simple adjustment to the processing technology of the reflective sheet structure is required, resulting in low cost.

[0006] Furthermore, the reflector includes a first side, a second side, a third side, and a fourth side. The first side is adjacent to the lamp bead assembly. The second side, the third side, and the fourth side are each provided with a cut portion and a stepped portion. The cut portion is located between two of the stepped portions.

[0007] In the above scheme, the first side adjacent to the LED assembly retains a complete reflective surface to ensure that the incident light from the LEDs is efficiently guided into the light guide plate and to avoid initial light loss. The second, third, and fourth sides, which are not on the side of the LED assembly, are provided with cut-out sections and stepped sections. The cut-out sections form gaps with the side of the frame, so that some edge light passes directly through the reflective sheet and is absorbed by the back plate, reducing the light intensity. When the light is transmitted along the edge of the light guide plate, it escapes (energy attenuation) when it encounters the cut-out section, and is scattered back to the central area of ​​the light guide plate when it encounters the stepped section. The escape of edge light is suppressed by physical blocking and scattering.

[0008] Furthermore, it also includes an optical film assembly and a light-shielding adhesive, wherein the optical film assembly is connected to the side of the light guide plate away from the reflective sheet, and the light-shielding adhesive is bonded to the periphery of the adhesive frame.

[0009] In the above solution, the light-shielding adhesive is attached to the periphery of the frame, which can absorb stray light escaping from the edge of the light guide plate, prevent bright lines from being visible through the frame, and block external ambient light from entering the module, thereby improving display contrast. Especially under strong light, the light-shielding adhesive can also fill the gap between the frame and the optical film assembly, prevent dust from entering and enhance mechanical stability. During the transmission of light from the light guide plate through the optical film assembly to the LCD panel, the optical film assembly improves the effective light utilization rate, while the light-shielding adhesive blocks ineffective edge light.

[0010] Furthermore, the light-shielding adhesive includes a first light-shielding part, a second light-shielding part, a third light-shielding part, and a fourth light-shielding part connected end to end. The first light-shielding part covers the lamp bead assembly, and the second, third, and fourth light-shielding parts are respectively opposite to the second, third, and fourth sides.

[0011] In the above scheme, the first light-shielding part directly blocks the direct light from the high-intensity LED assembly, preventing light from leaking out from the gap. The second, third, and fourth light-shielding parts work together with the reflector to absorb the scattered light with the light-shielding adhesive, avoiding secondary reflection.

[0012] Furthermore, the gap is smaller than the width of the second, third, and fourth light-shielding portions.

[0013] In the above scheme, the gap formed by the side cutting of the reflective sheet allows some edge light to pass through and be absorbed by the back plate, which reduces the light intensity for the first time. The width of the light-shielding adhesive is greater than the gap, ensuring that all residual light passing through the gap is completely absorbed, avoiding secondary reflection or light leakage.

[0014] Furthermore, the frame is light gray in color.

[0015] In the above solution, color powder is added to the frame during manufacturing to turn the original white frame into a light gray frame. During processing, the color powder is added directly to the plastic raw material (such as PC / ABS) and injection molded in one piece. No subsequent spraying or film application is required, resulting in low process cost. Compared with the traditional white frame (L value > 90), the light gray frame (L value 60~80) can reduce the edge light reflectivity and significantly reduce the secondary reflection of light from the edge of the light guide plate on the inner wall of the frame, thereby improving the bright line.

[0016] Furthermore, the optical film assembly includes a diffuser sheet, a lower prism sheet, and an upper prism sheet arranged sequentially, with the diffuser sheet covering the light guide plate.

[0017] In the above scheme, the diffuser scatters the discrete light emitted from the light guide plate a second time, eliminating the dot or lamp bead imaging (Mura effect), the lower prism converges the vertical light, improving the axial brightness, and the upper prism is arranged orthogonally to the lower prism to converge the horizontal light, further brightening and widening the viewing angle.

[0018] Furthermore, a stepped structure is provided on one side of the frame, and an FPC assembly is installed on the stepped structure, with the LED assembly connected to the FPC assembly.

[0019] In the above solution, the LED chip assembly is fixed to the FPC assembly by SMT or ACF (anisotropic conductive adhesive). The FPC assembly is a flexible circuit board. The stepped structure provides a mounting reference surface. The stepped structure forms a height difference on the side wall of the frame. The FPC assembly is attached to the stepped plane to avoid direct contact with the light guide plate or optical film and prevent squeezing damage. The vertical side wall formed by the stepped structure and the frame restricts the lateral displacement of the FPC and improves shock resistance.

[0020] Furthermore, the outer periphery of the frame is provided with multiple protruding structures, and the back plate is provided with multiple connecting slots corresponding to the positions of the protruding structures, with the protruding structures embedded in the connecting slots.

[0021] In the above solution, by setting a protruding structure on the outer periphery of the frame and opening a connecting slot at the corresponding position on the back plate, the frame and the back plate are accurately positioned and mechanically locked, making assembly simple.

[0022] A display screen includes a backlight module for improving brightness lines as described in any of the above embodiments.

[0023] This invention provides a backlight module and display screen for improving bright lines, which has the advantages of improving display contrast, simple structure, and low cost. By leaving a certain gap between the side of the reflective sheet and the inner periphery of the frame, the total internal reflection path of light between the frame and the reflective sheet is disrupted. The gap design allows some light escaping from the edge of the light guide plate to be absorbed by the back plate, and some to be scattered by the reflective sheet to the effective display area, thereby balancing edge and center brightness and improving bright lines. Especially for backlight modules with narrow bezel frames, reducing edge light leakage results in higher black purity in dark conditions, with significant effects, particularly in HDR or high-contrast scenes. Only simple adjustments to the reflective sheet structure processing technology are required, resulting in low cost. Attached Figure Description

[0024] Figure 1 This is an exploded view of a backlight module and display screen for improving brightness lines according to one embodiment.

[0025] Figure 2 This is a schematic diagram of a backlight module according to one embodiment.

[0026] Figure 3 for Figure 2 A partial schematic diagram.

[0027] Figure 4 for Figure 2 A magnified view of a portion of point A in the middle.

[0028] Figure 5 This is a schematic diagram of the location of the light-shielding adhesive in one embodiment.

[0029] Figure 6 This is an exploded view of an optical film assembly according to one embodiment.

[0030] Reference numerals: 1. Backplate; 11. Connecting slot; 2. Adhesive frame; 21. Raised structure; 22. Stepped structure; 3. Light guide plate; 4. Reflective sheet; 401. Cutting section; 402. Stepped section; 41. First side; 42. Second side; 43. Third side; 44. Fourth side; 5. Lamp bead assembly; 6. Gap; 7. Optical film assembly; 71. Diffuser; 72. Lower prism sheet; 73. Upper prism sheet; 8. Light-shielding adhesive; 81. First light-shielding section; 82. Second light-shielding section; 83. Third light-shielding section; 84. Fourth light-shielding section; 9. FPC assembly. Detailed Implementation

[0031] The following will describe in further detail a backlight module and display screen for improving brightness lines according to specific embodiments and accompanying drawings.

[0032] like Figures 1 to 3As shown in a preferred embodiment, a backlight module for improving brightness lines according to this utility model includes a back plate 1, a frame 2, a light guide plate 3, and a reflective sheet 4. The frame 2 is connected to the inner periphery of the back plate 1. The light guide plate 3 and the reflective sheet 4 are embedded in the frame 2. An LED assembly 5 is provided between one side of the frame 2 and the light guide plate 3. The reflective sheet 4 is located between the light guide plate 3 and the back plate 1, and a gap 6 is formed between the side of the reflective sheet 4 and the inner periphery of the frame 2. By leaving a certain gap 6 between the side of the reflective sheet 4 and the inner periphery of the frame 2, the total internal reflection path of light between the frame 2 and the reflective sheet 4 can be disrupted. The design of the gap 6 allows some of the light escaping from the edge of the light guide plate 3 to be absorbed by the back plate 1, and some to be scattered by the reflective sheet 4 to the effective display area, thereby balancing the brightness of the edge and the center and improving brightness lines. Especially for backlight modules with narrow-bezel frames 2, after reducing edge light leakage, the black purity in dark states is higher, especially in HDR or high-contrast scenes, the effect is significant. Only simple adjustments to the processing technology of the reflective sheet 4 structure are required, resulting in low cost.

[0033] like Figures 2 to 4 As shown, in some embodiments, the reflector 4 includes a first side 41, a second side 42, a third side 43 and a fourth side 44. The first side 41 is adjacent to the lamp bead assembly 5. The second side 42, the third side 43 and the fourth side 44 are each provided with a cutting portion 401 and a step portion 402. The cutting portion 401 is located between the two step portions 402. The first side 41 adjacent to the LED assembly 5 retains a complete reflective surface to ensure that the incident light from the LED is efficiently guided into the light guide plate 3, avoiding initial light loss. The second side 42, the third side 43, and the fourth side 44 on the side other than the LED assembly 5 are provided with a cutting part 401 and a step part 402. The cutting part 401 forms a gap 6 with the side of the frame 2, so that some edge light passes directly through the reflective sheet 4 and is absorbed by the back plate 1, reducing the light intensity. When the light is transmitted at the edge of the light guide plate 3, it escapes partly when it encounters the cutting part 401 (energy attenuation), and is scattered back to the central area of ​​the light guide plate 3 when it encounters the step part 402. The escape of edge light is suppressed by physical blocking and scattering.

[0034] like Figure 5 and Figure 6 As shown, in some embodiments, an optical film assembly 7 and a light-shielding adhesive 8 are also included. The optical film assembly 7 is connected to the side of the light guide plate 3 away from the reflective sheet 4, and the light-shielding adhesive 8 is adhered to the periphery of the frame 2. The light-shielding adhesive 8, adhered to the periphery of the frame 2, can absorb stray light escaping from the edge of the light guide plate 3, preventing bright lines from being visible through the frame. At the same time, it blocks external ambient light from entering the module, improving display contrast. Especially under strong light, the light-shielding adhesive 8 can also fill the gap between the frame 2 and the optical film assembly 7, preventing dust from entering and enhancing mechanical stability. During the transmission of light from the light guide plate 3 through the optical film assembly 7 to the liquid crystal panel, the optical film assembly 7 improves the effective light utilization rate, while the light-shielding adhesive 8 blocks ineffective edge light.

[0035] like Figure 5 and Figure 6 As shown, in some embodiments, the light-shielding adhesive 8 includes a first light-shielding portion 81, a second light-shielding portion 82, a third light-shielding portion 83, and a fourth light-shielding portion 84 connected end to end. The first light-shielding portion 81 covers the LED assembly 5, and the second light-shielding portion 82, the third light-shielding portion 83, and the fourth light-shielding portion 84 are respectively opposite to the second side 42, the third side 43, and the fourth side 44. The first light-shielding portion 81 directly blocks the direct light from the high-intensity LED assembly 5, preventing light leakage from the gaps. The second light-shielding portion 82, the third light-shielding portion 83, and the fourth light-shielding portion 84 work together with the reflector 4 to absorb the scattered light, avoiding secondary reflection.

[0036] like Figure 5 As shown, in some embodiments, the gap 6 is smaller than the width of the second light-shielding part 82, the third light-shielding part 83, and the fourth light-shielding part 84. The gap 6 formed by the side cutting of the reflective sheet 4 allows some edge light to pass through and be absorbed by the back plate 1, reducing the light intensity for the first time. The width of the light-shielding adhesive 8 is greater than the gap 6, ensuring that all residual light passing through the gap 6 is completely absorbed, avoiding secondary reflection or light leakage.

[0037] In some embodiments, the frame 2 is light gray. Color powder is added during the manufacturing process to transform the original white frame 2 into a light gray one. The color powder is added directly to the plastic raw material (such as PC / ABS) during processing, and the frame is integrally molded through injection molding, eliminating the need for subsequent spraying or film application. This reduces processing costs. Compared to the traditional white frame 2 (L value > 90), the light gray frame 2 (L value 60~80) reduces edge light reflectivity, significantly reducing secondary reflection of light from the edge of the light guide plate 3 on the inner wall of the frame 2, thereby improving the bright lines.

[0038] like Figure 6 As shown, in some embodiments, the optical film assembly 7 includes a diffuser 71, a lower prism sheet 72, and an upper prism sheet 73 arranged sequentially, with the diffuser 71 covering the light guide plate 3. The diffuser 71 scatters the discrete light emitted from the light guide plate 3 a second time, eliminating dot or lamp bead imaging (Mura effect). The lower prism sheet 72 converges the light in the vertical direction, improving axial brightness. The upper prism sheet 73 is arranged orthogonally to the lower prism sheet 72, converging the light in the horizontal direction, further brightening and widening the viewing angle.

[0039] like Figure 6As shown, in some embodiments, a stepped structure 22 is provided on one side of the frame 2, and an FPC assembly 9 is mounted on the stepped structure 22. The LED assembly 5 is connected to the FPC assembly 9. The LED assembly 5 is fixed to the FPC assembly 9 by SMT or ACF (anisotropic conductive adhesive). The FPC assembly 9 is a flexible circuit board. The stepped structure 22 provides a mounting reference surface. The stepped structure 22 forms a height difference on the side wall of the frame 2. The FPC assembly 9 is attached to the stepped plane to avoid direct contact with the light guide plate 3 or optical film, thus preventing squeezing damage. The vertical side wall formed by the stepped structure 22 and the frame 2 restricts the lateral displacement of the FPC and improves shock resistance.

[0040] like Figure 1 As shown, in some embodiments, the outer periphery of the frame 2 is provided with multiple protruding structures 21, and the back plate 1 is provided with multiple connecting slots 11 corresponding to the positions of the protruding structures 21, with the protruding structures 21 embedded in the connecting slots 11. By providing protruding structures 21 on the outer periphery of the frame 2 and opening connecting slots 11 at corresponding positions on the back plate 1, precise positioning and mechanical locking of the frame 2 and the back plate 1 are achieved, simplifying assembly.

[0041] A display screen includes a backlight module for improving brightness lines as described in any of the above embodiments.

[0042] This utility model discloses the working principle and process of a backlight module and display screen for improving brightness lines. Light from the LED assembly 5 is incident horizontally from the side of the light guide plate 3 and scattered by the dot matrix of the light guide plate 3 to the display surface. The first light-shielding part 81 of the light-shielding adhesive 8 completely covers the LEDs on the LED assembly 5, blocking direct light leakage. After the light reaches the edge of the light guide plate 3, part of it passes through the gap 6 formed by the cut part 401 of the reflective sheet 4 and the frame 2 and is absorbed by the back plate 1. The remaining light is scattered by the stepped part 402 of the reflective sheet 4. At the same time, some of the edge light can be absorbed by the light gray frame 2, further improving the brightness lines.

[0043] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0046] Although the description of this utility model has been given in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A backlight module for improving the bright line, characterized in that, The back plate, the rubber frame, the light guide plate and the reflecting sheet are included, the rubber frame is connected with the inner circumferential side of the back plate, the light guide plate and the reflecting sheet are embedded in the rubber frame, the lamp bead assembly is arranged between one side of the rubber frame and the light guide plate, the reflecting sheet is located between the light guide plate and the back plate, and the side edge of the reflecting sheet and the inner circumferential side of the rubber frame form a gap.

2. The backlight module for improving the bright line according to claim 1, wherein, The reflecting sheet includes a first side edge, a second side edge, a third side edge and a fourth side edge, the first side edge is adjacent to the lamp bead assembly, the second side edge, the third side edge and the fourth side edge are provided with cutting parts and step parts, and the cutting parts are located between the two step parts.

3. The backlight module for improving the bright line according to claim 2, wherein, The optical film assembly and the light shielding rubber are further included, the optical film assembly is connected with the side of the light guide plate away from the reflecting sheet, and the light shielding rubber is attached to the circumferential side of the rubber frame.

4. The backlight module for improving the bright line according to claim 3, wherein, The light shielding rubber includes first, second, third and fourth light shielding parts connected in head-to-tail mode, the first light shielding part covers the lamp bead assembly, and the second, third and fourth light shielding parts are opposite to the second, third and fourth side edges respectively.

5. The backlight module for improving the bright line according to claim 4, wherein, The gap is smaller than the width of the second, third and fourth light shielding parts.

6. The bright line improving backlight module according to claim 1, wherein, The rubber frame is light gray.

7. The backlight module for improving the bright line according to claim 3, wherein, The optical film assembly includes a diffusion sheet, a lower prism sheet and an upper prism sheet arranged in sequence, and the diffusion sheet covers the light guide plate.

8. The bright line improving backlight module according to claim 1, wherein, One side of the rubber frame is provided with a step structure, an FPC assembly is installed on the step structure, and the lamp bead assembly is connected with the FPC assembly.

9. The bright line improving backlight module of claim 1, wherein, A plurality of protruding structures are arranged on the outer circumferential side of the rubber frame, a plurality of connecting notches are arranged on the back plate corresponding to the positions of the protruding structures, and the protruding structures are embedded in the connecting notches.

10. A display screen, characterized by The improved bright line backlight module includes any one of claims 1 to 9.

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