Backlight module and display apparatus

Abstract

A backlight module defines an abutting direction (D1), and comprises a back plate (10), a limiting member (20), a reflective sheet (30), a light guide plate (40), and a light-emitting element (50). The limiting member (20) is disposed on the back plate (10) and has an abutting surface (21) and a guide surface (22) which are connected to one another, and a gap (23) adjacent to the guide surface (22); the reflective sheet (30) is disposed on the back plate (10), the light guide plate (40) being disposed on the reflective sheet (30), and the light-emitting element (50) being located on one side of the light guide plate (40); the reflective sheet (30) has a first side edge (31), a second side edge (32), and a cut line (33), the incision of the cut line (33) being located on the first side edge (31), a bending portion (34) being provided between the cut line (33) and the second side edge (32), and the bending portion (34) abutting against the abutting surface (21) of the limiting member (20). As the reflective sheet (30) expands along the abutting direction (D1), the bending portion (34) extends along the guide surface (22) of the limiting member (20) into the gap (23) of the limiting member (20). A display apparatus comprises the backlight module and a display panel (60).

Description

Backlight module and display device Technical Field

[0001] The present invention provides a backlight module and a display device, in particular to a backlight module capable of preventing optical quality from being affected by expansion, and a display device using the backlight module. Background Art

[0002] The edge-lit backlight module includes a back panel, a light-emitting element, a light guide plate and a reflector. The light-emitting element is arranged on the back panel and is located on a light-entering side. The reflector is arranged on the back panel. The light guide plate is located on the reflector and is projected by the light-emitting element.

[0003] Among them, each component in the backlight module is designed with a dimensional margin to accommodate the tolerances that may occur in component manufacturing and assembly. At room temperature, the side of the reflector close to the light-incident side needs to extend under the light-emitting element to ensure the reflector's effect of reflecting light.

[0004] However, when the ambient temperature of the backlight module is high, causing thermal expansion of various components, the reflector may contact other components and cause deformation and warping, thereby affecting the optical quality of the backlight module. If the original size of the reflector is reduced, the gap between the reflector and the light-emitting element will increase, which may cause the reflector at room temperature to be unable to extend under the light-emitting element, thereby affecting the optical quality and causing optical loss.

[0005] Summary of the Invention

[0006] The main purpose of the present invention is to provide a backlight module and a display device, wherein the backlight module can accommodate the expansion and contraction of a reflective sheet and maintain a limiting function, thereby preventing the expansion of the reflective sheet from affecting the optical quality and achieving the purpose of maintaining the optical quality after the challenge test.

[0007] To achieve the aforementioned objectives, the backlight module of the present invention defines a top-supporting direction and includes:

[0008] a back plate having a bearing surface;

[0009] a position-limiting member disposed on the supporting surface of the back plate, the position-limiting member comprising a top contact surface and a guide surface connected to each other, and having a gap, wherein the guide surface is adjacent to the gap;

[0010] a reflective sheet located on the supporting surface of the back plate;

[0011] a light guide plate disposed on the reflective sheet; and

[0012] a light-emitting element located on one side of the light guide plate;

[0013] The reflector has a first side edge, a second side edge and a cutting line. The cutout of the cutting line is located on the first side edge. There is a bent portion between the cutting line and the second side edge. The bent portion abuts against the top surface of the limiting member. As the reflector expands along the top direction, the bent portion of the reflector extends along the guide surface of the limiting member into the gap of the limiting member.

[0014] The reflective sheet of the backlight module of the present invention abuts the top abutting surface of the stopper in a normal state and is limited by the stopper. As the reflective sheet expands, the curved portion can extend along the guide surface of the stopper into the gap of the stopper, preventing the reflective sheet from deforming or warping due to expansion. Furthermore, no gap is required at the end of the reflective sheet adjacent to the light-emitting element, thereby ensuring the optical quality and stability of the backlight module and avoiding optical loss. The cut-off line of the reflective sheet ensures that, when the reflective sheet expands, the curved portion bends to extend into the gap of the stopper. The gap of the stopper allows the reflective sheet to have a wider range of expansion and contraction margins, thereby increasing the tolerance for manufacturing and assembly tolerances of the various components of the backlight module and enhancing the convenience of manufacturing and assembly.

[0015] To achieve the aforementioned objectives, the present invention further provides a display device comprising:

[0016] The backlight module as described above; and

[0017] A display panel is located on a side of the light guide plate away from the back plate.

[0018] The display device of the present invention is provided with the backlight module, so that the optical quality is not affected by the expansion or displacement of the reflective sheet, thereby maintaining better optical quality and avoiding optical loss, and is suitable for application in vehicle-mounted side-entry devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a side cross-sectional schematic diagram of a reflective sheet in an unexpanded state according to a preferred embodiment of the backlight module of the present invention.

[0020] FIG2 is a side cross-sectional schematic diagram of a reflective sheet in an expanded state according to a preferred embodiment of the backlight module of the present invention.

[0021] Figure 3: A partially enlarged view of Figure 2.

[0022] FIG4 is a partial top plan view of the backlight module of the present invention.

[0023] FIG5 is a partial three-dimensional schematic diagram of the back plate, the limiting member and the reflective sheet of the backlight module of the present invention.

[0024] FIG6 is a partial exploded schematic diagram of the back plate, the limiting member and the reflective sheet of the backlight module of the present invention.

[0025] FIG7 is a partial side cross-sectional schematic diagram of a preferred embodiment of the display device of the present invention. DETAILED DESCRIPTION

[0026] Please refer to FIG. 1 , which shows a preferred embodiment of the backlight module of the present invention. The backlight module defines a top direction D1 and includes a back plate 10 , a stopper 20 , a reflector 30 , a light guide plate 40 and a light emitting element 50 .

[0027] As shown in Figures 1 and 2, the back panel 10 has a bearing surface 11, the limiting member 20 is arranged on the bearing surface 11 of the back panel 10, the limiting member 20 has a top abutment surface 21 and a guide surface 22 connected to each other, and has a gap 23, the guide surface 22 is adjacent to the gap 23, the reflective sheet 30 is located on the bearing surface 11 of the back panel 10, the light guide plate 40 is arranged on the reflective sheet 30, and the light-emitting element 50 is located on one side of the light guide plate 40.

[0028] As shown in FIG4 , the reflector 30 has a first side edge 31 , a second side edge 32 and a cutoff line 33 . The cutoff line 33 is located on the first side edge 31 . A bent portion 34 is provided between the cutoff line 33 and the second side edge 32 . The bent portion 34 abuts against the top abutting surface 21 of the position-limiting member 20 . As shown in FIG1 and FIG2 , as the reflector 30 expands along the abutting direction D1 , the bent portion 34 of the reflector 30 extends along the guide surface 22 of the position-limiting member 20 into the gap 23 of the position-limiting member 20 . The light-emitting element 50 projects light onto the light guide plate 40 , and the reflector 30 reflects the light toward the light guide plate 40 .

[0029] When the backlight module of the present invention is in normal dimensions and has not expanded or contracted, such as at room temperature, the reflective sheet 30 abuts the top abutting surface 21 of the stopper 20 and is restrained by the stopper 20. As shown in FIG1 , the end of the reflective sheet 30 adjacent to the light-emitting element 50 can extend below the light-emitting element 50, ensuring that the entire reflective surface of the reflective sheet 30 extends from the first side edge 31 to the opposite side edge. This ensures that the reflective surface of the reflective sheet 30 is flat and complete, thereby maintaining the optical quality of the backlight module. As shown in FIG2 and FIG4 , if the reflective sheet 30 expands, the curved portion 34 can extend along the guide surface 22 of the stopper 20 into the gap 23 of the stopper 20, preventing the reflective sheet 30 from deforming or warping due to expansion. Furthermore, no gap is required at the end of the reflective sheet 30 adjacent to the light-emitting element 50. Therefore, the optical quality and stability of the backlight module are ensured, and optical loss is avoided to maintain luminous efficiency. The cut-off line 33 of the reflective sheet 30 can ensure that when the reflective sheet 30 expands, the bent portion 34 bends to extend into the gap 23 of the limiting member 20 .

[0030] Furthermore, taking into account the manufacturing and assembly tolerances of the various components of the backlight module, through the cooperation between the reflector 30 and the limiter 20, when assembling the backlight module, it is only necessary to pay attention to that the end of the reflector 30 adjacent to the light-emitting element 50 can extend below the light-emitting element 50, and the bent portion 34 of the reflector 30 can be flat and abut against the top abutment surface 21 of the limiter 20, or it can be bent and extend into the gap 23 of the limiter 20. Regardless of whether the bent portion 34 is bent or not, when the reflector 30 is in a thermal expansion state, it will not affect the extension of the bent portion 34 to the gap 23 of the limiter 20 or deeper into the gap 23. Therefore, the gap 23 of the limiter 20 can give the reflector 30 a wider range of expansion and contraction margin, and increase the tolerance for the manufacturing and assembly tolerances of the various components of the backlight module, thereby improving the convenience of manufacturing and assembly.

[0031] In addition, in one embodiment of the backlight module, the end of the reflective sheet 30 adjacent to the light emitting element 50 is not fixed to the back plate 10 by means of tape or other components, and is therefore a free end. The bent portion 34 is located at the other end of the reflective sheet 30. Under normal temperature conditions, the reflective sheet 30 is restrained by the stopper 20, so that the free end of the reflective sheet 30 can extend below the light emitting element 50 without displacement, thereby ensuring the optical quality of the backlight module. In the expanded state, the reflective sheet 30 is restrained by the stopper 20. The curved portion 34 of the reflector 30 extends into the gap 23 of the limiter 20, so that most of the expansion of the reflector 30 is received by the gap 23 of the limiter 20. Although the free end of the reflector 30 will expand and extend below the light-emitting element 50, if the free end of the reflector 30 contacts other components and cannot extend, the curved portion 34 of the reflector 30 can continue to extend into the gap 23 of the limiter 20, thereby effectively preventing the reflector 30 from deforming and warping.

[0032] In addition, as shown in FIG3 , the abutting surface 21 and the guide surface 22 of the position-limiting member 20 are connected by an arcuate segment 24. If the reflective sheet 30 expands and causes the curved portion 34 to move along the abutting direction D1, the curved portion 34 can smoothly move from the abutting surface 21 to the guide surface 22 along the arcuate segment 24. In other words, the arcuate segment 24 can reduce the resistance encountered by the curved portion 34 in moving from the abutting surface 21 to the guide surface 22, thereby preventing the movement of the curved portion 34 from being obstructed.

[0033] As shown in Figures 4 to 6, the cutting line 33 is located outside the limiter 20 and adjacent to the limiter 20, so that the width of the bent portion in a transverse direction D2 is approximately aligned with the edge of the limiter 20, so that the bent portion has appropriate structural strength and is not unable to provide sufficient supporting force due to being too narrow, or difficult to bend due to being too wide. Furthermore, the reflector 30 has an extension portion 35 connected to the first side edge 31. The cutoff line 33 is formed between the curved portion 34 and the extension portion 35, and the extension portion 35 does not contact the stopper 20. When the reflector 30 expands, the extension portion 35 and the curved portion 34 are separated by the cutoff line 33. The curved portion 34 is located below the gap 23 of the stopper 20 and is not supported by the stopper 20, which makes it easy to bend. The extension portion 35 is still supported by the supporting surface 11 of the backplate. Therefore, the extension portion 35 is not driven by the curved portion 34 to bend downward, but remains independently flat. Therefore, the extension portion 35 can still reflect light normally. At the same time, by designing the cutoff line 33 close to the stopper 20, the width of the extension portion 35 in the transverse direction D2 is preserved as much as possible, thereby enhancing the light reflection effect of the extension portion 35 and improving the luminous efficiency of the backlight module.

[0034] In addition, as shown in Figures 2, 4, and 5, the back panel 10 has a frame 12, which is located at the edge of the supporting surface 11, preferably at the edge of the supporting surface 11 along the abutting direction D1. The stopper 20 abuts against the frame 12, and the extension 35 is spaced apart from the frame 12. The stopper 20 can be fixed and positioned by abutting against the frame 12, thereby enhancing the limiting effect of the stopper 20 on the reflective sheet 30. A space is left between the extension 35 and the frame 12. Therefore, when the reflective sheet 30 expands and causes the extension 35 to extend toward the frame 12, the extension 35 will not contact the frame 12, thereby preventing the reflective sheet 30 from being squeezed and deformed, thereby ensuring the optical quality of the backlight module. Specifically, the limiting member 20 is made of an elastic material and is integrally formed, and has a supporting portion 25 and a side wall 26 connected to each other. The supporting portion 25 is arranged on the supporting surface 11 of the back plate 10, and the reflective sheet 30 is located on the supporting portion 25. The side wall 26 is basically located on one side of the supporting portion 25 along the top direction D1 and abuts against the frame 12. The top surface 21, the guide surface 22 and the arc segment 24 are formed on the bottom side of the side wall 26, and the gap 23 is formed between the supporting portion 25 and the side wall 26.

[0035] Preferably, as shown in Figures 1, 5 and 6, the limiting member 20 is located at a corner of the back plate 10 and is provided on the side of the light guide plate 40 away from the light-emitting element 50. By providing a limiting member 20 at each of the two corners of the back plate 10, the reflective sheet 30 can be effectively limited without affecting the main light-emitting surface of the backlight module. The extension 35 of the reflective sheet 30 is located between the two limiting members 20 and does not contact the limiting member 20. In addition, the back plate 10 also has a positioning groove 13, which is adjacent to the frame 12. The positioning groove 13 is recessed in the supporting surface 11. The limiting member 20 is provided in the positioning groove 13, thereby improving the fixing effect of the limiting member 20 and the convenience of assembling the limiting member 20.

[0036] As shown in Figures 4 to 6, the second side edge 32 of the reflector 30 is concave toward the cut-off line 33 to form a recessed portion 36. The recessed portion 36 and the cut-off line 33 are respectively located on either side of the curved portion 34. The provision of the recessed portion 36 can weaken the structural rigidity of the curved portion 34 on the second side edge 32 and increase the flexibility of the curved portion 34, making it easier for the curved portion 34 to bend when pushed. The rigidity of the portion of the curved portion 34 that is pushed can still be maintained, so that the curved portion 34 can be reliably pushed into the gap 23 of the limiting member 20. Furthermore, the recessed portion 36 can be designed into different shapes. For example, the recessed portion 36 can be concave in an arc or V-shape, or a hole can be set on the second side edge 32, as long as the structural rigidity of the second side edge 32 can be weakened. In this embodiment, the recessed portion 36 is arc-shaped, which can make the bending position of the bent portion 34 in the top direction D1 more consistent, so that the reflector 30 can more easily push the bent portion 34 into the gap 23 of the limit member 20.

[0037] Furthermore, as shown in Figures 1 and 4, the reflector 30 has a main body 37, and the area where the main body 37 is located is the visible area of ​​the backlight module. The cut-off line 33 extends from the first side edge 31 toward the center of the reflector 30 to the edge that contacts the main body 37. The bent portion 34 is connected to the main body 37, and the recessed portion 36 is located outside the main body 37. Since the cut-off line 33, the recessed portion 36 and the bent portion 34 are all located outside the visible area, they will not affect the optical effect of the visible area of ​​the backlight module. In addition, the recessed portion 36 is closer to the main body 37 and farther away from the first side edge 31, so that the bent portion 34 is more easily guided by the guide surface 22 of the limiting member 20. Furthermore, the cutoff line 33 can be parallel or non-parallel to the abutting direction D1. In this embodiment, the cutoff line 33 is parallel to the abutting direction D1, which ensures that the connection between the bent portion 34 and the main body 37 is wide enough, so that the bent portion 34 has sufficient structural rigidity. Therefore, when the reflector 30 expands and pushes against the bent portion 34, the bent portion 34 can reliably extend into the gap 23 of the stopper 20, thereby ensuring that the main body 37 of the reflector 30 does not deform or warp. When the cutoff line 33 is non-parallel to the abutting direction D1, as long as the end of the cutoff line 33 extends toward the center of the reflector 30 to a sufficient extent to allow the bent portion 34 to bend relative to the main body 37, the desired effect of the present invention can also be achieved.

[0038] Please refer to FIG. 7 , which is a preferred embodiment of the display device provided by the present invention, comprising a backlight module and a display panel 60 . The display panel 60 is located on a side of the light guide plate 40 away from the back plate 10 , and the backlight module projects light onto the display panel 60 .

[0039] The display device of the present invention is provided with the backlight module, which can accommodate the expansion and contraction of the reflector 30 and maintain the limiting function, thereby preventing the optical quality from being affected by the expansion or displacement of the reflector 30. Therefore, it can maintain better optical quality and avoid optical loss, and is suitable for application in automotive side-entry models.

[0040] In summary, the backlight module cooperates with the limiter 20 through the reflector 30. When the reflector 30 expands, the curved portion 34 can bend and be guided by the guide surface 22 of the limiter 20 to extend into the gap 23 of the limiter 20. Therefore, the reflector 30 can be prevented from warping and the end of the reflector 30 adjacent to the light-emitting element 50 can be prevented from displacement. Therefore, the optical quality and optical stability of the backlight module can be ensured, and optical loss can be avoided.

[0041]

Explanation of symbols

[0042] 10: Back panel

[0043] 11: Bearing surface

[0044] 12: Border

[0045] 13: Positioning slot

[0046] 20: Limiting parts

[0047] 21: Top surface

[0048] 22: Guide surface

[0049] 23: Gap

[0050] 24: Arc segment

[0051] 25: Bearing part

[0052] 26: Sidewall

[0053] 30: Reflective sheet

[0054] 31: First side edge

[0055] 32: Second side edge

[0056] 33: Cut the line

[0057] 34: Bend

[0058] 35: Extension

[0059] 36: Depression

[0060] 37: Body part

[0061] 40: Light guide plate

[0062] 50: Light-emitting element

[0063] 60: Display panel

[0064] D1: Pushing direction

[0065] D2: Horizontal direction.

Claims

1. A backlight module having a top direction and comprising: a back plate having a bearing surface; A limiting member, the limiting member is arranged on the bearing surface of the back plate, the limiting member has a top abutting surface and a guiding surface connected to each other, and has a gap, and the guiding surface is adjacent to the gap; A reflective sheet, which is located on the bearing surface of the back plate; A light guide plate, which is disposed on the reflective sheet; and A light emitting element, which is located on one side of the light guide plate; The reflector sheet has a first side edge, a second side edge and a cutting line, the cut of the cutting line is located on the first side edge, a bending portion is provided between the cutting line and the second side edge, the bending portion abuts against the top abutting surface of the position-limiting member, and as the reflector sheet expands along the abutting direction, the bending portion of the reflector sheet extends along the guide surface of the position-limiting member into the gap of the position-limiting member. 2 . The backlight module as claimed in claim 1 , wherein the stopper is located at a corner of the back plate and is disposed on a side of the light guide plate away from the light emitting element. 3 . The backlight module as claimed in claim 1 , wherein the cutting line is parallel to the abutting direction. 4 . The backlight module as claimed in claim 1 , wherein the cutting line is located outside the limiting member and adjacent to the limiting member. 5 . The backlight module as claimed in claim 1 , wherein the top abutting surface and the guiding surface of the position-limiting member are connected by an arc segment. 6 . The backlight module as claimed in claim 1 , wherein the reflective sheet has an extension portion connected to the first side edge, the cutoff line is formed between the bent portion and the extension portion, and the extension portion and the stopper are not in contact with each other. 7 . The backlight module according to claim 6 , wherein the back plate has a frame, the frame is located at an edge of the carrying surface, the limiting member abuts against the frame, and the extending portion is spaced apart from the frame. 8 . The backlight module according to claim 1 , wherein the second side edge of the reflective sheet is concave toward the cutting line to form a recessed portion, and the recessed portion and the cutting line are respectively located on two sides of the curved portion.

9. The backlight module as claimed in claim 8, wherein the reflector has a main body, the cutting line extends from the first side edge toward the center of the reflector to an edge contacting the main body, the bent portion is connected to the main body, and the recessed portion is located outside the main body.

10. A display device, comprising: The backlight module according to any one of claims 1 to 9; and The display panel is located at a side of the light guide plate away from the back plate.

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