Backlight module and display device

Abstract

A backlight module of the present invention comprises a back plate, a reflective sheet, a lamp board and at least one connecting structure, wherein the back plate has a bearing surface, the reflective sheet is arranged on the bearing surface of the back plate in a stacking direction, the lamp board is located between the reflective sheet and the back plate, the connecting structure comprises a notch and a protruding post, the back plate and the reflective sheet are combined by means of the notch and the protruding post, the notch has an opening and a guide surface that are connected, the guide surface is inclined relative to the bearing surface in a guide direction, and one end of the protruding post passes through the opening of the notch and engages against the guide surface. When the reflective sheet undergoes thermal expansion, a pulling force that pulls the reflective sheet towards the back plate is generated by means of the connecting structure, which can suppress the deformation and bulging of the reflective sheet, thereby maintaining the optical quality of the backlight module. A display device of the present invention comprises the backlight module and a display panel disposed on the backlight module.

Description

Backlight module and display device Technical Field

[0001] The invention relates to a backlight module and a display device comprising the backlight module. Background Art

[0002] Today's direct-lit backlight module includes a back panel, a reflector, and a light panel. The light panel is located between the back panel and the reflector. The back panel is provided with a plurality of fixing points. Screws are inserted into the fixing points to lock the back panel, the light panel, and the reflector to complete the assembly.

[0003] Since the reflector and the back plate are made of different materials, the expansion coefficient of the reflector is greater than that of the back plate. When heated, the reflector expands more than the back plate. At this time, since the reflector and the back plate are fixed together by screws, the distance between two adjacent fixing points is limited by the back plate with a smaller expansion amount. As a result, the portion of the reflector with a larger expansion amount between adjacent fixing points cannot extend along the plane, but will deform and bulge upward, affecting the optical quality of the backlight module and even causing the light-emitting elements on the lamp board to be pushed and fall off.

[0004] Summary of the Invention

[0005] The primary purpose of the present invention is to provide a backlight module and a display device that can mitigate the problem of thermal expansion affecting the optical quality of the backlight module and the display device. The backlight module of the present invention can withstand challenging tests in harsh environments. Specifically, by improving the integration of the reflector and backplate, the reflector's expansion in the Z-axis is reduced, thereby enhancing the backlight module's adaptability to harsh environmental challenges.

[0006] To achieve the aforementioned objectives, the backlight module of the present invention comprises:

[0007] a back plate having a bearing surface;

[0008] a reflective sheet disposed on the supporting surface of the back plate along a stacking direction;

[0009] a light panel located between the reflector and the back panel; and

[0010] At least one connecting structure, the at least one connecting structure includes a notch and a protrusion, the back plate and the reflector are connected by the notch and the protrusion, the notch has an opening and a guide surface connected to each other, the guide surface is inclined relative to the supporting surface along a guiding direction, and one end of the protrusion passes through the opening of the notch and buckles against the guide surface.

[0011] The back panel and the reflector of the backlight module of the present invention are connected by the at least one connecting structure, and the thermal expansion characteristics of the reflector are utilized to reduce the deformation and bulging of the reflector due to expansion. As the reflector expands, the protrusion and the groove of the at least one connecting structure move relative to each other, and the end of the protrusion abuts against the guide surface of the groove and moves guided by the guide surface, thereby generating a pulling force that pulls the reflector toward the back panel, which can suppress the bulging of the reflector, thereby maintaining the optical quality of the backlight module. The more the end of the protrusion abuts against the guide surface, the greater the pulling force will be generated, thereby effectively suppressing the expansion and deformation of the reflector.

[0012] The display device of the present invention in combination with the above-mentioned backlight module can achieve the purpose of more stable light uniformity performance in harsh environments. To achieve the above-mentioned purpose, the present invention further provides a display device comprising:

[0013] The backlight module as described above; and

[0014] A display panel is located on a side of the reflective sheet away from the back plate.

[0015] By utilizing the backlight module, the display device of the present invention can effectively prevent the optical quality from being affected by the thermal expansion and deformation of the reflector, and can provide more stable light uniformity and improved reliability in harsh environments. Therefore, the display device is particularly suitable for use in products with high ambient temperatures or large temperature differences, such as automotive display products. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a top exploded schematic diagram of a preferred embodiment of the backlight module of the present invention.

[0017] FIG2 is a bottom-view exploded schematic diagram of the backlight module of the present invention.

[0018] FIG3 is a perspective schematic diagram of the backlight module of the present invention.

[0019] FIG4 is a schematic diagram showing the combination of the notch and the protrusion of the connection structure of the backlight module of the present invention.

[0020] FIG5A is a cross-sectional view of the connection structure of the backlight module of the present invention before displacement occurs.

[0021] FIG5B is a cross-sectional view of the connection structure of the backlight module of the present invention after displacement.

[0022] FIG6 is a bottom plan view of the connection structure of the backlight module of the present invention.

[0023] FIG7 is a cross-sectional view of the backlight module of the present invention having a positioning member.

[0024] FIG8 is a cross-sectional view of the connection structure of the backlight module of the present invention located between the positioning members.

[0025] FIG9 is a partial bottom-view plan view of the backlight module of the present invention.

[0026] FIG10 is a partial bottom plan view of another embodiment of the backlight module of the present invention.

[0027] FIG11 is a cross-sectional view showing a positioning member of the backlight module of the present invention located between connection structures.

[0028] FIG12 is a schematic cross-sectional view of the display device of the present invention. DETAILED DESCRIPTION

[0029] Please refer to FIG. 1 to FIG. 3 , which illustrate a preferred embodiment of the backlight module of the present invention, which includes a back plate 10 , a reflective sheet 20 , a light board 30 and at least one connecting structure 40 .

[0030] As shown in Figures 1, 4, 5A and 5B, the back panel 10 has a supporting surface 11, the reflector 20 is arranged on the supporting surface 11 of the back panel 10 along a stacking direction D1, the light panel 30 is located between the reflector 20 and the back panel 10, and the at least one connecting structure 40 includes a notch 41 and a protrusion 42. The back panel 10 and the reflector 20 are combined with the notch 41 and the protrusion 42. The notch 41 has an opening 411 and a guide surface 412 connected to each other. The guide surface 412 is inclined relative to the supporting surface 11 along a guiding direction D2, and an end 421 of the protrusion 42 passes through the opening 411 of the notch 41 and buckles against the guide surface 412. The back panel 10 and the reflector 20 can be combined by the boss 42 of the at least one connecting structure 40 buckling against the guide surface 412 of the notch 41, and the boss 42 can move along the guide surface 412. Therefore, as the reflector 20 expands, the end 421 of the boss 42 abuts against the guide surface 412 and is guided by the guide surface 412 to move along the guide direction D2.

[0031] The back panel 10 and the reflective sheet 20 of the backlight module of the present invention are connected by the at least one connecting structure 40. The reflective sheet 20 expands and generates relative movement with the back panel 10, that is, the reflective sheet 20 expands along the guide direction D2 or expands away from the back panel 10, so that the protrusion 42 and the groove 41 of the at least one connecting structure 40 also move relative to each other. At this time, the end 421 of the protrusion 42 will be guided by the guide surface 412 and move, thereby generating a pulling force that pulls the reflective sheet 20 toward the back panel 10, thereby suppressing the expansion and deformation of the reflective sheet 20, thereby reducing the degree to which the optical quality of the backlight module is affected.

[0032] Comparing Figures 5A and 5B , Figure 5A illustrates a cross-sectional view of the connection structure 40 coupled to the back panel 10 at room temperature, while Figure 5B illustrates a cross-sectional view of the reflective sheet 20 and the back panel 10 after expansion of the reflective sheet 20. The at least one connection structure 40 utilizes the thermal expansion characteristics of the reflective sheet 20 to suppress deformation and swelling caused by expansion of the reflective sheet 20. When the reflective sheet 20 is not deformed by expansion, the end 421 of the protrusion 42 still engages the guide surface 412 of the notch 41, thereby maintaining the connection between the reflective sheet 20 and the back panel 10. Furthermore, when the reflector sheet 20 expands beyond the trust interval due to heat, it is prone to significant deformation. By suppressing deformation of the reflector sheet 20 by the at least one connecting structure 40, the reflector sheet 20 is prevented from expanding beyond the trust interval, thereby maintaining the optical quality of the backlight module and providing greater reliability, thereby enhancing the adaptability of the backlight module to harsh environmental challenges. Furthermore, the use of the connecting structure 40 eliminates the need for additional screws or tape to secure the reflector sheet 20 to suppress its expansion, thereby reducing costs and assembly time.

[0033] Furthermore, the guide surface 412 is inclined along the guide direction D2 in a direction opposite to the stacking direction D1. Therefore, the further the end 421 of the protrusion 42 moves against the guide surface 412 along the guide direction D2, the greater the pulling force will be generated, thereby effectively suppressing the expansion and deformation of the reflector 20. Regardless of whether the groove 41 and the protrusion 42 of the at least one connecting structure 40 are located on the reflector 20 and the other is located on the back plate 10, when the reflector 20 expands thermally, a pulling force can be generated through the at least one connecting structure 40, thereby suppressing the expansion degree of the reflector 20.

[0034] In addition, the notch 41 and the protrusion 42 of the at least one connecting structure 40 can be integrally formed with the reflector 20 or the back panel 10, or can be formed as independent components and installed on the reflector 20 or the back panel 10. In this embodiment, the protrusion 42 is arranged on the reflector 20, and the notch 41 is arranged on the back panel 10, so it is more convenient to process and manufacture. In addition, the notch 41 can be in the shape of a groove or a hole. In this embodiment, the notch 41 is in the shape of a hole and is directly formed on the back panel 10. The opening 411 of the notch 41 is formed on the supporting surface 11 of the back panel 10, so that the notch 41 is easier to process and form, and the protrusion 42 is integrally formed with the reflector 20, so it is more convenient because no additional assembly is required.

[0035] As shown in Figures 4 to 6, the end 421 of the protrusion 42 of the at least one connecting structure 40 is formed with a shoulder 422. The shoulder 422 protrudes laterally from the end 421. The shoulder 422 forms at least two point contacts with the guide surface 412 of the notch 41 of the at least one connecting structure 40. This increases the contact area between the end 421 of the protrusion 42 and the guide surface 412, thereby improving the mobility of the protrusion 42 guided by and moving along the guide surface 412. In other examples, the shoulder 422 and the guide surface 412 of the notch 41 of the at least one connecting structure 40 can also be in line contact or surface contact. For example, the shoulder 422 protrudes laterally from the end 421 and is inclined, preferably in combination with the guide surface 412 being inclined along the guide direction D2 toward the direction opposite to the stacking direction D1, to ensure that the protrusion 42 of the at least one connecting structure 40 forms surface contact with the groove 41, thereby improving the combination stability of the two.

[0036] In addition, as shown in Figures 4 to 6, the boss 42 of the at least one connecting structure 40 has a column portion 423, the end portion 421 is connected to one end of the column portion 423, the diameter of the column portion 423 is smaller than the diameter of the end portion 421, and the opening 411 of the slot 41 of the at least one connecting structure 40 has a connected expansion section 413 and a narrowing section 414, the diameter of the narrowing section 414 is smaller than the diameter of the end portion 421 of the boss 42, the end portion 421 of the boss 42 can pass through the expansion section 413, and the column portion 423 of the boss 42 can enter the narrowing section 414 from the expansion section 413. It should be noted that the expansion section 413 referred to in the present invention refers to a section that allows the end 421 of the boss 42 to pass through, but is not limited to this; relative to the expansion section 413, the narrowing section 414 referred to in the present invention refers to a section that allows the columnar portion 423 of the boss 42 to pass through but the end 421 cannot pass through, and can allow the end 421 to rest against the section on one side of the narrowing section 414. In this embodiment, when the reflector 20 is combined with the back plate 10, the end 421 and the shoulder 422 of the protrusion 42 of the at least one connecting structure 40 pass through the expanded hole section 413 of the opening 411 of the notch 41 and abut against the guide surface 412 of the notch 41. As the reflector 20 expands, the reflector 20 drives the protrusion 42 to move along the guiding direction D2. The guiding surface 412 of the notch 41 causes the end 421 of the protrusion 42 to move opposite to the stacking direction D1 and generate a pulling force on the reflector 20. The column portion 423 of the protrusion 42 enters the narrowed section 414, so that the shoulder 422 abuts against the guide surface 412 over a larger area, and can prevent the end 421 from falling out of the notch 41, thereby improving the connection stability between the protrusion 42 and the notch 41. Preferably, the contour of the shoulder 422 can be elliptical or polygonal, and the contour of the reaming section 413 of the opening 411 corresponds to the contour of the shoulder 422. In this embodiment, the contour of the shoulder 422 is elliptical, which can facilitate forcing the boss 42 into the groove 41, thereby improving the convenience of assembly.

[0037] Furthermore, as shown in Figures 1, 2, 5A and 5B, the lamp board 30 is formed with at least one through hole 31, the position of the at least one through hole 31 corresponds to the at least one connecting structure 40, and the boss 42 of the at least one connecting structure 40 passes through the corresponding at least one through hole 31, and the contour of the at least one through hole 31 corresponds to the expanded hole section 413 and the narrowed section 414 of the opening 411 of the groove 41, so the end 421 of the boss 42 can pass through the portion of the at least one through hole 31 corresponding to the expanded hole section 413, and when the column portion 423 of the boss 42 enters the narrowed section 414 of the opening 411, the column portion 423 is also adjacent to the portion of the through hole 31 of the lamp board 30 corresponding to the narrowed section 414, so that the connecting structure 40 provides a limiting effect on the back panel 10 and the lamp board 30 at the same time, which has the effect of improving the overall assembly stability.

[0038] In addition, as shown in Figure 7, in one embodiment of the backlight module, the backlight module further includes at least one fixing member 50, which is fixedly connected to the back panel 10 and the reflective sheet 20. The at least one connecting structure 40 and the at least one fixing member 50 are spaced apart along the guiding direction D2. The at least one fixing member 50 is fixedly connected to the back panel 10 and the reflective sheet 20 to become a fixed point. As the reflective sheet 20 expands, the back panel 10 and the reflective sheet 20 will not produce relative displacement at the position of the fixed point, and the reflective sheet 20 will expand outward from the fixed point and extend along the guiding direction D2. The at least one connecting structure 40 is arranged at the position of the fixed point along the guiding direction D2, so that it can effectively generate tension when the reflective sheet 20 expands to suppress deformation and bulging of the reflective sheet 20. The at least one fixing member 50 can be a screw or other component that can fix the back panel 10 and the reflective sheet 20.

[0039] Furthermore, as shown in Figure 8, in another aspect of the backlight module, the backlight module includes a plurality of the connecting structures 40, and the plurality of connecting structures 40 are spaced apart relative to the at least one fixing member 50 along the guiding direction D2, and the guiding surfaces 412 of the plurality of connecting structures 40 are inclined in the same direction. When the fixing member 50 is located approximately close to the edge of the backlight module, so that the area of ​​the reflective sheet 20 on one side of the fixing member 50 is larger than the area on the other side, the expansion degree of the side with the larger area of ​​the reflective sheet 20 will be greater than that of the side with the smaller area. At this time, the plurality of connecting structures 40 are arranged on the side with the larger area of ​​the reflective sheet 20, and the guiding surfaces 412 of the plurality of connecting structures 40 are inclined in the same direction, so that the expansion of the reflective sheet 20 can be suppressed, thereby suppressing the part of the reflective sheet 20 with a larger expansion degree, thereby improving the effect of suppressing expansion. More specifically, with the at least one fixing member 50 as a reference, the inclined direction of the guide surface 412 in each of the connecting structures 40 is such that the farther away from the fixing member 50 , the closer the reflective sheet 20 is to the back plate 10 .

[0040] In addition, as shown in Figures 8 and 9, when the backlight module has a long side 12, the guiding direction D2 is parallel to the long side 12, and the backlight module includes a plurality of the connecting structures 40, and the plurality of connecting structures 40 are arranged at intervals parallel to the long side 12 of the backlight module. That is, when the backlight module is longer in one direction and has the long side 12, and is shorter in another direction and has a short side 13, the reflective sheet 20 will have a greater degree of expansion on the long side 12 of the backlight module. Therefore, by arranging the plurality of connecting structures 40 at intervals along the long side 12 of the backlight module, the expansion of the reflective sheet 20 can be suppressed in sections, thereby effectively preventing the reflective sheet 20 from deforming and bulging. Furthermore, as shown in FIG9 , a plurality of fixing members 50 can be spaced apart on the backlight module parallel to the short side 13 of the backlight module, and the connecting structure 40 is provided in the direction parallel to the long side 12 of each fixing member 50, so that the reflective sheet 20 is more comprehensively suppressed by the connecting structure 40 to ensure the optical quality of the backlight module.

[0041] In addition, as shown in FIG10 , in another embodiment of the backlight module, the backlight module includes a plurality of connecting structures 40 and a plurality of fixing members 50, wherein the plurality of connecting structures 40 are located between two adjacent fixing members 50. For example, the backlight module has a short side 13 extending in a direction different from that of the long side 12. In this embodiment, the short side 13 and the long side 12 are perpendicular to each other, but the present invention is not limited thereto. The provision of the plurality of fixing members 50 improves the stability of the connection between the back plate 10 and the reflector 20. Since the portion of the reflector 20 located between the two fixing members 50 is more likely to bulge along the stacking direction D1 during thermal expansion, the plurality of connecting structures 40 connecting the reflector 20 and the back plate 10 can reduce or prevent deformation or bulging of the reflector 20, thereby maintaining the optical quality of the backlight module.

[0042] As shown in FIG. 11 , in another embodiment of the backlight module, the backlight module includes a plurality of connection structures 40 , the at least one fixing member 50 is located between the connection structures 40 , and the guide surfaces 412 of the plurality of connection structures 40 are inclined in opposite directions. Since the reflective sheet 20 expands outward from the fixing point, it expands in different directions on different sides of the fixing member 50. Therefore, the guiding direction D2 is actually parallel to the supporting surface 11 of the back plate 10 and is defined based on the expansion direction of the reflective sheet 20. For example, when the fixing member 50 is located approximately in the middle of the backlight module, the reflective sheet 20 on the left side of the fixing member 50 will expand and extend toward the left. In this case, the guiding direction D2 of the guiding surface 412 of the connecting structure 40 on the left side of the fixing member 50 is toward the left. Conversely, the reflective sheet 20 on the right side of the fixing member 50 will expand and extend toward the right. In this case, the guiding direction D2' of the guiding surface 412 of the connecting structure 40 on the right side of the fixing member 50 is toward the right. Therefore, the expansion and deformation of the reflective sheet 20 can be suppressed on different sides of the fixing member 50, thereby ensuring that the backlight module has a uniform optical quality. In addition, according to needs, the guiding directions D2 of the multiple connecting structures 40 can also be tangent to each other or oblique. As long as the guiding directions D2 of the multiple connecting structures 40 are in the same direction as the expansion direction of the reflector 20, the effect of suppressing the expansion of the reflector 20 can be achieved. By providing multiple connecting structures 40, the connection stability between the back panel 10 and the reflector 20 can also be improved.

[0043] Please refer to FIG. 12 , which illustrates another preferred embodiment of a display device provided by the present invention. The display device includes a backlight module and a display panel 60. The display panel 60 is located on the side of the reflector 20 away from the back plate 10. The backlight module is capable of projecting light onto the display panel 60. By incorporating the backlight module, the display device of the present invention can reduce the impact of thermal expansion and deformation of the reflector 20 on optical quality and improve reliability. Therefore, the display device is particularly suitable for use in products with high ambient temperatures or large temperature fluctuations, such as in-vehicle displays.

[0044] For example, by designing a limiting mechanism on the bottom surface of the injection-molded reflector and combining it with a corresponding limiting mechanism on the backplane, a three-axis (XYZ) positioning effect is achieved. This prevents component deformation during harsh environmental testing, resulting in NGs, and reduces work hours, enhancing the competitive advantage of direct-lit backlight modules. For example, in automotive / TV designs, this shortens development time and eliminates assembly-related issues, further reducing production costs.

[0045] In summary, the back plate 10 and the reflective sheet 20 of the backlight module of the present invention are connected by the at least one connecting structure 40. When the reflective sheet 20 expands, the protrusion 42 of the at least one connecting structure 40 is guided by the guide surface 412 of the groove 41 to generate tension, which can suppress the degree of deformation and bulging of the reflective sheet 20. For example, the deformation of the reflective sheet 20 in the Z-axis direction is reduced, thereby achieving the effect of improving the adaptability of the backlight module to harsh environmental challenges, thereby maintaining the optical quality of the backlight module and the display device, and improving the reliability of the backlight module and the display device.

[0046] [Description of Reference Numerals]

[0047] 10: Back panel

[0048] 11: Bearing surface

[0049] 12: Long side

[0050] 13: Short side

[0051] 20: Reflective sheet

[0052] 30: Light board

[0053] 31: Through hole

[0054] 40: Connection structure

[0055] 41: Missing slot

[0056] 411: Open

[0057] 412: Guide surface

[0058] 413: Expansion section

[0059] 414: Narrow section

[0060] 42: convex column

[0061] 421: End

[0062] 422: Shoulders

[0063] 423: Column

[0064] 50: Fixing parts

[0065] 60: Display panel

[0066] D1: Stacking direction

[0067] D2, D2': Guidance direction.

Claims

1. A backlight module, comprising: a back plate having a load-bearing surface; A reflective sheet, the reflective sheet being arranged on the bearing surface of the back plate along a stacking direction; a light panel, the light panel being located between the reflector and the back panel; and At least one connection structure, the at least one connection structure includes a notch and a convex column, the back plate and the reflector are connected by the notch and the convex column, the notch has a connected opening and a guide surface, the guide surface is inclined relative to the bearing surface along the guiding direction, and the end of the convex column passes through the opening of the notch and buckles against the guide surface. 2 . The backlight module as claimed in claim 1 , wherein when the reflective sheet expands due to heat, the end of the protrusion abuts against the guiding surface and is guided by the guiding surface.

3. The backlight module as claimed in claim 1, wherein a shoulder is formed at the end of the convex column of the at least one connecting structure, the shoulder protrudes laterally from the end, and the shoulder forms at least two point contacts with the guide surface of the notch of the at least one connecting structure.

4. The backlight module as claimed in claim 1, wherein a shoulder is formed at an end of the convex column of the at least one connecting structure, the shoulder protrudes laterally from the end, and the shoulder is in surface contact with a guide surface of the notch of the at least one connecting structure. 5 . The backlight module as claimed in claim 1 , wherein the convex column is disposed on the reflective sheet, the notch is disposed on the back plate, and an opening of the notch is formed on a bearing surface of the back plate.

6. The backlight module as described in claim 1, wherein the boss of the at least one connecting structure has a body portion, the end portion is connected to one end of the body portion, the diameter of the body portion is smaller than the diameter of the end portion, the opening of the notch of the at least one connecting structure has a connected expansion section and a narrowing section, the diameter of the narrowing section is smaller than the diameter of the end portion of the boss, the end portion of the boss can pass through the expansion section, and the body portion of the boss can enter the narrowing section from the expansion section.

7. The backlight module as claimed in claim 1, wherein the backlight module has a long side, the guiding direction is parallel to the long side, and the backlight module comprises a plurality of the connecting structures, and the plurality of connecting structures are arranged in parallel with the long side of the backlight module at intervals.

8. The backlight module as claimed in claim 1, wherein the backlight module comprises at least one fixing member, the at least one fixing member is fixedly connected to the back plate and the reflective sheet, and the at least one connecting structure and the at least one fixing member are spaced apart along the guiding direction.

9. The backlight module as claimed in claim 8, wherein the backlight module comprises a plurality of the connection structures, the plurality of connection structures are arranged at intervals along the guiding direction relative to the at least one fixing member, and the guiding surfaces of the plurality of connection structures are inclined in the same direction. 10 . The backlight module as claimed in claim 8 , wherein the backlight module comprises a plurality of the connection structures and a plurality of the fixing members, and the plurality of the connection structures are located between two adjacent fixing members. 11 . The backlight module as claimed in claim 8 , wherein the backlight module comprises a plurality of the connecting structures, the at least one fixing member is located between the connecting structures, and the guide surfaces of the plurality of connecting structures are inclined in opposite directions.

12. The backlight module as claimed in any one of claims 1 to 11, wherein the lamp panel is formed with at least one through hole, the position of the at least one through hole corresponds to the at least one connecting structure, and the protrusion of the at least one connecting structure passes through the corresponding at least one through hole.

13. A display device, comprising: The backlight module according to any one of claims 1 to 12; and The display panel is located at a side of the reflective sheet away from the back plate.

Images