Backlight module, display module and display device

Abstract

The application discloses a backlight module, a display module and a display device. The backlight module comprises a back plate, a light guide plate and at least two lamp strips. The back plate comprises a bottom plate and a plurality of side plates arranged around the bottom plate. The plurality of side plates and the bottom plate enclose an assembly space. The light guide plate is located in the assembly space. The light guide plate comprises a plurality of side surfaces. Each side surface is arranged opposite to a side plate. Each side surface has a first gap with the opposite side plate. Each lamp strip is arranged in a different first gap. The light emitting side of the lamp strip is opposite to the side surface of the light guide plate. The first gap with the lamp strip is a first sub-gap. A plurality of elastic members are located in each first sub-gap. The backlight module can ensure that the light entry efficiency of the lamp strip does not change obviously and ensure the stability of the display brightness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display device, in particular to a backlight module, a display module and a display device. BACKGROUND

[0002] With the diversification of display application environment, the product requirements and specifications of display from form, performance and parameters are also more and more various. At present, the demand for display screen is increasing in outdoor or large public places, and the display in this use environment generally requires high brightness and resistance to extreme weather such as high temperature / low temperature.

[0003] In order to achieve high brightness design of display screen, side-in design can be used. Single side-in light design cannot meet the demand of more than 1000 nit brightness. In order to meet the high brightness design, the design is generally double long side light, double short side light or single short side + single long side L type light. The use environment condition of display screen is generally-30℃~60℃, and the design needs to consider that when lighting in high temperature environment, enough expansion gap of light guide plate is reserved.

[0004] The light guide plate is generally rectangular. In the backlight structure of single light bar, the light bar is located at one side of the light guide plate, and the limiting structure of the light guide plate is arranged at the three sides of the light guide plate without light bar, which can ensure that the light guide plate does not move under different placement conditions. However, the display in outdoor or large public places needs double light bar design. If the limiting is only performed at the side of the light guide plate without light bar, the limiting may be insufficient. This will cause the light guide plate to move greatly under different conditions such as display upright, inverted, horizontal or vertical, and the brightness of the display at the same position will appear floating difference, which seriously affects the display brightness stability of the display. SUMMARY

[0005] The present application provides a backlight module, a display module and a display device. The backlight module can ensure that the light efficiency of the light source on the light bar does not change obviously, and ensures the stability of display brightness.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] A backlight module comprises:

[0008] A back plate comprises a bottom plate and a plurality of side plates arranged around the bottom plate, and the plurality of side plates and the bottom plate enclose an assembly space;

[0009] A light guide plate is located in the assembly space, and the light guide plate comprises a plurality of side surfaces, each side surface is arranged opposite to a side plate, and each side surface has a first gap with the opposite side plate;

[0010] At least two light bars, each of the light bars is arranged in a different first gap, a light emitting side of the light bar is opposite to a side surface of the light guide plate, a first gap with the light bar is a first sub-gap, and the first gap without the light bar is a second sub-gap;

[0011] A plurality of elastic members, at least part of the elastic members are located in each of the first sub-gaps.

[0012] Optionally, a length l of the elastic member along an extension direction of the first sub-gap in which the elastic member is located satisfies: Wherein, F n is a force during compression of the elastic member, E is a tensile strength of the elastic member, Δl is a compression amount of the elastic member after being subjected to the force, l0 is a thickness of the elastic member along a width direction of the first sub-gap in which the elastic member is located, and h is a thickness of a part of the elastic member in contact with the light guide plate along a thickness direction of the light guide plate.

[0013] Optionally, the plurality of elastic members include first elastic members located at two ends of each of the first sub-gaps, and the light bar is located between the two first elastic members in the first sub-gap.

[0014] Optionally, in the first sub-gap, a non-light emitting side of the light bar is fixedly connected with the side plate, and a second gap is formed between a light emitting side of the light bar and the side surface of the light guide plate.

[0015] Optionally, the heat dissipation plate further includes a first heat dissipation part located between the non-light emitting side of the light bar and the side plate.

[0016] The non-light emitting side of the light bar is bonded to the first heat dissipation part, and the light emitting side of the light bar abuts against the side surface of the light guide plate.

[0017] The plurality of elastic members include at least one second elastic member located between the first heat dissipation part and the side plate.

[0018] Optionally, the heat dissipation plate further includes a second heat dissipation part in contact with the bottom plate.

[0019] A side of the bottom plate facing the light guide plate has a relief groove opposite to the second heat dissipation part, and the second heat dissipation part is in slidable contact with a bottom of the relief groove.

[0020] Optionally, the light emitting side of the light bar has a transparent protective structure abutting against the side surface of the light guide plate.

[0021] Optionally, the light bar comprises a substrate, a plurality of light sources and a connector, the substrate comprises a first part and a second part, the first part is located in the first sub-gap and extends along the extension direction of the first sub-gap, the second part is located on one side of the first part along the thickness direction of the light guide plate, the second part extends out of the assembly space through the opening on the back plate, the plurality of light sources are located on the side of the first part facing the light guide plate, and the connector is located on the second part.

[0022] Optionally, the plurality of elastic members further comprises a third elastic member located at both ends of the second sub-gap.

[0023] Optionally, at the corner of the intersecting first sub-gap and second sub-gap, the third elastic member is connected with the first elastic member.

[0024] Optionally, among the intersecting third elastic member and first elastic member, the length of the third elastic member along the extension direction of the first gap in which it is located is greater than the length of the first elastic member along the extension direction of the first gap in which it is located.

[0025] Optionally, the shape of the structure where each third elastic member intersects with the first elastic member is different.

[0026] Optionally, the plurality of elastic members further comprises a fourth elastic member located in the middle region of the second sub-gap.

[0027] Optionally, the thickness of the elastic member along the width direction of the first gap in which it is located in the natural stretched state is greater than the width of the first gap.

[0028] The sum of the widths of the two opposite first gaps is greater than the expansion amount of the light guide plate in the arrangement direction of the two opposite first gaps.

[0029] Optionally, the distance from the surface of the elastic member away from the bottom plate to the first plane is less than or equal to the distance from the surface of the light guide plate away from the bottom plate to the first plane, and the first plane is the plane where the surface of the light guide plate facing the bottom plate is located.

[0030] Optionally, the material of the elastic member is rubber material.

[0031] Optionally, it further comprises an adhesive member located in the middle region of the second sub-gap, and the side surface of the light guide plate is bonded to the side plate through the adhesive member.

[0032] Optionally, in the second sub-gap, the adhesive member is in a compressed state under the action of the light guide plate and the side plate.

[0033] Optionally, the adhesive member is double-sided foam tape.

[0034] Optionally, the plurality of side surfaces comprises two opposite first side surfaces and two opposite second side surfaces, the first side surfaces are adjacent to the second side surfaces, and the length of the first side surface is greater than the length of the second side surface.

[0035] The at least two light bars comprise a first light bar and a second light bar located in first gaps between the two first side surfaces and the corresponding side plates, respectively, and the distance of the first light bar from the light guide plate is equal to the distance of the second light bar from the light guide plate.

[0036] Optionally, the backlight module further comprises a white reflective sheet located between the light guide plate and the bottom plate and an optical film material located on the side of the light guide plate away from the bottom plate.

[0037] Optionally, the area of the bottom plate adjacent to the side plate is formed with a reinforcing rib, the reinforcing rib protrudes towards the side of the bottom plate away from the light guide plate, and the side of the reinforcing rib towards the light guide plate is formed with a reinforcing rib groove.

[0038] The backlight module further comprises a bottom pad located in the reinforcing rib groove, the white reflective sheet is located between the bottom pad and the light guide plate, and the bottom pad abuts against the white reflective sheet.

[0039] Optionally, the bottom pad is integrally formed with the elastic member.

[0040] Optionally, the surface of the light guide plate away from the bottom plate is in a prism structure.

[0041] Optionally, the apex angle of the prism in the prism structure of the surface of the light guide plate away from the bottom plate is in an arc shape.

[0042] Optionally, the optical film material comprises a lower prism film, an upper prism film, and a reflective polarized brightness enhancement film, the lower prism film is located on the side of the light guide plate away from the bottom plate, the upper prism film is located on the side of the lower prism film away from the bottom plate, and the polarized brightness enhancement film is located on the side of the upper prism film away from the lower prism film.

[0043] The prism structure on the light guide plate has a plurality of first prisms extending in a first direction in parallel, the lower prism film has a plurality of second prisms extending in a second direction in parallel, the upper prism film has a plurality of third prisms extending in the first direction in parallel, and the first direction is perpendicular to the second direction.

[0044] Optionally, the backlight module further comprises a middle frame, the middle frame comprises a fixing portion surrounding the light guide plate and a window portion located on the side of the optical film material away from the bottom plate, the fixing portion is fixedly connected with the side plate, and the window portion has a window corresponding to the effective light emitting area of the light guide plate.

[0045] Optionally, the edges of the film layers in the optical film material have a plurality of extensions, the side plate or the fixing part or the elastic member has a plurality of positioning parts, each of the positioning parts is opposite to one of the extensions, and the optical film material is positioned by matching the extensions with the corresponding positioning parts on the side plate or the fixing part or the elastic member.

[0046] Optionally, the side of the elastic member away from the bottom plate has a stepped positioning part opposite to the extension, the stepped positioning part has at least one stepped surface, and the extension on each film layer in the optical film material is latched on the stepped surface.

[0047] Optionally, the stepped positioning part has one stepped surface, the stepped surface is flush with the surface of the optical film material towards the bottom plate, and the extension on each film layer in the optical film material is latched on the stepped surface; or,

[0048] The stepped positioning part has a plurality of stepped surfaces, the plurality of stepped surfaces are respectively flush with the surfaces of the optical film material towards the bottom plate, and the extension on each film layer in the optical film material is latched on the corresponding stepped surface.

[0049] Optionally, the side of the elastic member away from the bottom plate has a protruding positioning part matched with the extension, the extension has a first insertion hole matched with the protruding positioning part, and the protruding positioning part is matched and inserted into the first insertion hole.

[0050] Optionally, the film layers in the optical film material include opposite first edges and second edges, the first edges have at least one first extension, the first extension has a second insertion hole, the second edges have at least one second extension, and the second extension corresponds to the first extension one by one.

[0051] The side plate or the fixing part has a first positioning part matched with the first extension away from the bottom plate, the first positioning part includes a first recess and a boss at the bottom of the first recess, the first extension is located in the first recess, and the boss is inserted into the second insertion hole.

[0052] The side plate or the fixing part has a second positioning part matched with the second extension away from the bottom plate, and the second positioning part includes a second recess, and the second extension is located in the second recess.

[0053] Optionally, two side walls of the first extension arranged along the extension direction of the first edge have a third gap between the side walls of the first recess.

[0054] The two side walls of the second insertion hole arranged along the arrangement direction of the first edge and the second edge have a fourth gap between the side walls of the boss;

[0055] The two side walls of the second extension arranged along the extension direction of the second edge have a fifth gap between the side walls of the second groove, and the width of the fifth gap is equal to the width of the third gap;

[0056] The second edge has a sixth gap between the side plate where the second groove is located.

[0057] Optionally, the first edge has two first extensions, and the second edge has two second extensions, each of the second extensions is arranged opposite to one of the first extensions, wherein the third gap, the fourth gap and the fifth gap formed by one set of opposite first extensions and second extensions and the side plate or the fixed part are smaller than the third gap, the fourth gap and the fifth gap formed by another set of opposite first extensions and second extensions and the side plate or the fixed part.

[0058] The application further provides a display module, comprising the backlight module provided in any of the technical solutions and a display panel located at the light emitting side of the backlight module.

[0059] The application further provides a display device, comprising the display module provided in the technical solutions.

[0060] The application provides a backlight module, a display module and a display device. The backlight module comprises a back plate, a light guide plate, at least two lamp strips and a plurality of elastic members. The light guide plate and the back plate have a plurality of first gaps therebetween, so that the back plate can avoid interfering with the light guide plate. Each lamp strip is arranged in a different first gap. The first gap with the lamp strip is a first sub-gap, and the first gap without the lamp strip is a second sub-gap. Part of the elastic members are arranged in each first sub-gap, i.e., the elastic members are arranged in each first gap with the lamp strip between the light guide plate and the back plate. The elastic members in the first sub-gap can limit the light guide plate on the side with the lamp strip, so that the distance between the lamp strip and the side of the light guide plate can not change greatly, the light efficiency of the light source on the lamp strip can not change obviously, and the display brightness of the display module can be stable. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 A schematic view of a plane structure of a backlight module is provided for the embodiment of the application;

[0062] Figure 2 A cross-sectional view of a backlight module is provided for the embodiment of the application;

[0063] Figure 3 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0064] Figure 4 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0065] Figure 5 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0066] Figure 6 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0067] Figure 7 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0068] Figure 8 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0069] Figure 9 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0070] Figure 10 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0071] Figure 11 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0072] Figure 12 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0073] Figure 13 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0074] Figure 14 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0075] Figure 15 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0076] Figure 16 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0077] Figure 17 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0078] Figure 18 Another schematic view of the planar structure of the backlight module according to an embodiment of the present application is provided;

[0079] Figure 19 For Figure 18 Enlarged view of the B region;

[0080] Figure 20 A plan view of a positioning part provided in an embodiment of the present application;

[0081] Figure 21 A plan view of an optical film provided in an embodiment of the present application;

[0082] Figure 22 For Figure 21 Enlarged view of the C1 region;

[0083] Figure 23 For Figure 22 Enlarged view of the C2 region;

[0084] Figure 24 A structural view of a first sink provided in an embodiment of the present application;

[0085] Figure 25 A structural view of a first extension cooperating with the first sink provided in an embodiment of the present application;

[0086] Figure 26 A structural view of a second sink provided in an embodiment of the present application;

[0087] Figure 27 A structural view of a second extension cooperating with the second sink provided in an embodiment of the present application.

[0088] Icon:

[0089] 1-back plate; 11-bottom plate; 12-side plate; 111-avoidance groove; 112-stiffener; 113-stiffener groove; 113-first sink; 114-boss; 115-second sink; 2-light guide plate; 21-side surface; 22-prism structure; 3-lamp strip; 31-substrate; 311-first part; 312-second part; 32-light source; 33-connector; 34-transparent protective layer; 4-elastic member; 41-first elastic member; 42-second elastic member; 43-third elastic member; 44-fourth elastic member; 45-bottom pad; 46-step-shaped positioning part; 461-step surface; 47-protrusion-shaped positioning part; 5-radiating plate; 51-first radiating part; 52-second radiating part; 6-bonding member; 7-white reflective sheet; 8-optical film; 81-lower prism film; 82-upper prism film; 83-reflective polarizing gain film; 84-extension; 841-first insertion hole; 842-first extension; 8421-second insertion hole; 843-second extension. DETAILED DESCRIPTION

[0090] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0091] Currently, double-lamp-bar design is required in the backlight module of the display in outdoor or large public places. In order to ensure the stability of the brightness of the display, the position of the light guide plate in the backlight module needs to be limited. In the prior art, a limiting structure is generally arranged on the side of the light guide plate where no lamp bar is arranged. The light guide plate is generally in the shape of a rectangle. For the double-lamp-bar design in the backlight module, limiting is only performed on the side of the light guide plate where no lamp bar is arranged. In this way, the side of the light guide plate where the lamp bar is arranged may not be limited enough. This may result in that the light guide plate moves greatly in different conditions such as the display being placed upright, inverted, horizontally or vertically, and the distance between the light guide plate and the lamp bar changes greatly, and the brightness at the same position of the display fluctuates, which seriously affects the display brightness stability of the display.

[0092] To solve the above problems, the present application provides a backlight module, as shown in Figure 1 and Figure 2 , comprising:

[0093] a back plate 1, the back plate 1 comprises a bottom plate 11 and a plurality of side plates 12 arranged around the bottom plate 11, the plurality of side plates 12 and the bottom plate 11 enclose an assembly space;

[0094] a light guide plate 2, the light guide plate 2 is located in the assembly space, the light guide plate 2 comprises a plurality of side surfaces 21, each side surface 21 is opposite to a side plate 13, and each side surface 21 has a first gap A with the opposite side plate 12;

[0095] at least two lamp bars 3, each lamp bar 3 is arranged in a different first sub-gap A1, and the light-emitting side of the lamp bar 3 is opposite to the side surface 12 of the light guide plate. The first gap A with the lamp bar 3 is the first sub-gap A1, and the first gap A without the lamp bar is the second sub-gap A2;

[0096] a plurality of elastic members 4, at least part of the elastic members 4 are located in each first sub-gap A1.

[0097] The backlight module provided by the embodiment of the present application comprises a back plate 1, a light guide plate 2, at least two lamp strips 3 and a plurality of elastic members 4. The light guide plate 2 and the back plate 1 have a plurality of first gaps A therebetween, so that the back plate 1 does not interfere with the light guide plate 2. Each lamp strip 3 is arranged in a different first gap A. The first gap A with the lamp strip 3 is a first sub-gap A1, and the first gap A without the lamp strip is a second sub-gap A2. Some elastic members 4 are arranged in each first sub-gap A1, i.e. the elastic members 4 are arranged in each first gap A with the lamp strip 3 between the light guide plate 2 and the back plate 1. The elastic members 4 in the first sub-gap A1 can limit the light guide plate on the side with the lamp strip, so that the distance between the lamp strip and the side of the light guide plate does not change greatly, the light efficiency of the light source on the lamp strip does not change obviously, and the display brightness of the display module does not change at the same position, thereby ensuring the stability of the display brightness.

[0098] It should be noted that the shape of the backlight module can be rectangular or special-shaped, for example, the shape of the backlight module is hexagonal or octagonal. Correspondingly, the shape enclosed by the light guide plate and the side plate of the back plate in the backlight module matches the shape of the backlight module. Specifically, the shape of the backlight module is not limited here and can be determined according to the situation.

[0099] In actual application, as shown in Figure 1 The shape of the light exit surface of the light guide plate 2 can be rectangular. The plurality of side surfaces 21 of the light guide plate 2 can comprise two opposite first side surfaces 211 and two opposite second side surfaces 212. The first side surface 211 and the second side surface 212 are adjacent to each other, and the length of the first side surface 211 is greater than that of the second side surface 212. The at least two lamp strips 3 in the backlight module can comprise a first lamp strip 301 and a second lamp strip 302. The first lamp strip 301 and the second lamp strip 302 are arranged opposite to the two first side surfaces 211 of the light guide plate, i.e. the light guide plate of the backlight module adopts a double-long-side light entry mode. Compared with a single-side light entry mode, a double-short-side light entry mode or an L-shaped light entry mode, the double-long-side light entry mode can meet the demand for high brightness of the display module. The distance between the first lamp strip 301 and the light guide plate 2 is equal to the distance between the second lamp strip 302 and the light guide plate 2, so that the light efficiency of the light source on the lamp strip 301 and the lamp strip 302 on both sides of the light guide plate 2 is consistent.

[0100] In the above embodiment, as shown in Figure 1 The plurality of elastic members 4 can comprise first elastic members 41 arranged at both ends of the first sub-gap A1. The lamp strip 3 is arranged between the two first elastic members 41 in the first sub-gap. The two elastic members arranged at both ends of the lamp strip can limit the light guide plate.

[0101] The non-light-emitting side of the lamp strip 3 can be fixedly connected with the side plate 12, and the light-emitting side of the lamp strip 3 has a second gap with the side surface 21 of the light guide plate 2, so that interference between the lamp strip and the light guide plate is avoided, and the light guide plate is prevented from being deformed. The width of the second gap can be set according to the expansion amount of the light guide plate 2, and is not limited here, but is determined according to actual conditions.

[0102] In actual application, the light exit surface of the light guide plate 2 in the backlight module can be a rectangle, and the light guide plate 2 adopts double-long-side light incidence. Taking the backlight module of the 21.5-inch display device as an example, the parameters of the light guide plate 2 can be as shown in Table 1.

[0103] Table 1

[0104]

[0105] As can be seen from Table 1, the light guide plate 2 needs an expansion space of 0.55 mm in the width direction. Considering the tolerance, the width of the gap between the first side surface 211 of the light guide plate 2 and the corresponding side plate 12 in the width direction can be set to 0.4 mm. If the light guide plate 2 is not limited, the light guide plate 2 will move up and down under the action of gravity during the process of the single-side lamp strip being in the normal position (downward) and being in the upside-down position (upward). The gap between the single-side lamp strip 3 and the light guide plate 2 can be changed from 0.1 mm in the normal position to 0.9 mm in the upside-down position, and the single-side light incidence efficiency of the light guide plate 2 will be reduced by 26%. This seriously affects the single-side brightness stability of the light guide plate (the single-side brightness of the light guide plate can differ by 28% in the normal position and the upside-down position). By arranging two first elastic members 4 at both ends of the first sub-gap A1, the position of the light guide plate 2 can be limited. In order to improve the brightness stability of the light guide plate in different positions of the double lamp strips, it is necessary to control the single-side brightness variation of the light guide plate 2 to be within 1.5%. Therefore, it is necessary to adjust the sum of the lengths of the elastic members in the first sub-gap A1, and the gap between the light-emitting side of the lamp strip 3 and the light guide plate 2 is designed to be changed by 0.1 mm to 0.15 mm.

[0106] The elastic member 4 is elastically deformed under stress, and the length l of the elastic member 4 in the extension direction of the first sub-gap A1 satisfies: wherein F n is the stress during compression of the elastic member, E is the tensile strength of the elastic member, is a constant, Δl is the compression amount of the elastic member after being stressed, l0 is the thickness of the elastic member in the width direction of the first sub-gap, and h is the thickness of the part of the elastic member in contact with the light guide plate in the thickness direction of the light guide plate, which is approximately equal to the thickness of the light guide plate. l x h is the contact area of the elastic member and the light guide plate.

[0107] For example, Figure 1As shown, if only two first elastic members 41 are arranged in the first sub-gap A1 between the light guide plate 2 and the back plate 1 at the two ends of the light bar 3, when the display module is vertically lit (two light bars 3 are distributed vertically), the light guide plate 2 is compressed downward under the action of gravity, and the lower first elastic member 41 is deformed. According to the formula, Δl is calculated to be 0.05 mm. In order to ensure that Δl≤0.05 mm, the length of the first elastic member 41 in the first sub-gap A1 can be calculated by using the formula. Through the above data, it is calculated that the length of the first elastic member 41 in the first sub-gap A1 is greater than or equal to 3.9 mm, that is, Δl≤0.05 mm can be met.

[0108] When the space at the two ends of the light bar 3 in the first sub-gap A1 cannot meet the length requirement of the first elastic member 41, in order to ensure that Δl meets the requirement, the light bar 3 and the light guide plate 2 can be arranged without a gap, and the elastic member 4 can be arranged between the light bar 3 and the side plate 12. Through the elastic member between the light bar 3 and the side plate 12, the acting area of the elastic member on the light guide plate 2 is increased, and then the compression amount of the elastic member 4 by the light guide plate 2 is reduced, the moving range of the light guide plate 2 is reduced, and the display brightness stability of the display module is ensured.

[0109] Specifically, as shown in Figure 3 and Figure 4 As shown, the backlight module further includes a heat dissipation plate 5 in contact with the bottom plate 11. The heat dissipation plate 5 includes a first heat dissipation portion 51 located between the non-light-emitting side of the light bar 3 and the side plate 12. The non-light-emitting side of the light bar 3 is bonded to the first heat dissipation portion 51. The light-emitting side of the light bar 3 abuts against the side surface 21 of the light guide plate 2. The plurality of elastic members 4 includes at least one second elastic member 42 located between the first heat dissipation portion 51 and the side plate 12. In the above structure, the light-emitting side of the light bar 3 is in contact with the light guide plate 2. When the light guide plate 2 expands, the light guide plate 2 pushes the light bar 3 to move, the second elastic member 42 is compressed by the heat dissipation plate 5 to provide space for the expansion of the light guide plate 2, and the light-emitting effect of the light guide plate 2 is not affected. Moreover, the heat dissipation plate 5 can conduct the heat generated by the light-emitting of the light bar 3 out of the heat dissipation plate 5, avoiding failure of the light bar 3. The first heat dissipation portion 51 of the heat dissipation plate 5 can provide support to the light bar 3, avoiding deformation of the light bar 3 leading to uneven light emission of the light guide plate 2.

[0110] As shown in Figure 3 The first sub-gap A1 can be provided with a plurality of second elastic members 42. The light-emitting side of the light bar 3 has a plurality of light sources 32. Each second elastic member 42 can be arranged at a position corresponding to a light source 32. Specifically, the number, size and dimensions of the second elastic members 42 can be set according to actual conditions, which are not limited here.

[0111] It should be noted that the above-mentioned second elastic member 42 can be arranged separately in the first sub-gap A1, as shown in Figure 3 or can be arranged simultaneously with the first elastic member 41 in the first sub-gap A1, as shown inFigure 5 As shown, no restrictions are imposed here; it depends on the actual situation.

[0112] Specifically, such as Figure 4 As shown, the heat sink 5 further includes a second heat dissipation portion 52 that contacts the base plate 11. The base plate 11 has a relief groove 111 on the side facing the light guide plate 2 that is opposite to the second heat dissipation portion 52. The second heat dissipation portion 52 is slidably in contact with the bottom of the relief groove 111, which ensures that the heat on the heat sink 5 is dissipated from the base plate 11. Furthermore, it allows for a gap between the second heat dissipation portion 52 and the light guide plate 2, preventing interference between the second heat dissipation portion 52 and the light guide plate 2 or other film layers in the backlight module. The second heat dissipation portion 52 can be a plate-shaped portion perpendicular to the first heat dissipation portion 51.

[0113] Specifically, the heat sink 5 can be made of aluminum, which has good heat dissipation performance.

[0114] Among them, such as Figure 4 As shown, the light-emitting side of the aforementioned light strip 3 has a transparent protective structure 34 that abuts against the side surface 21 of the light guide plate 2. This transparent protective structure is located between the light source 32 on the light strip 3 and the light guide plate 2, thus ensuring that the light source 32 on the light strip 3 is not damaged during contact between the light-emitting side of the light strip and the light guide plate 2. Specifically, the hardness of the transparent protective structure 34 can be greater than the hardness of the light source 32 on the light strip 3. The thickness of the transparent protective structure 34 along the width direction of the first gap is greater than the thickness of the light source 32 along the width direction of the first gap, thus achieving the protective function of the transparent protective structure for the light source. The thickness of the transparent protective structure 34 can be 0.2 mm, or other values; no limitation is made here, and it depends on the actual situation.

[0115] The above-mentioned light strip 3 can be fixed to the back plate 1 or to the heat sink 5 by means of thermally conductive adhesive. This structure allows the heat generated by the light strip 3 to be quickly discharged from the base plate 11, increasing the service life of the backlight module.

[0116] Furthermore, when the first elastic element 41 is provided in the first sub-gap A1, the structure of the light strip can be designed to maximize the space available at both ends of the light strip within the first sub-gap A1 to meet the requirements. For example... Figure 6 As shown, the light strip 3 may include a substrate 31, multiple light sources 32 and a connector 33. The substrate 31 includes a first part 311 and a second part 312. The first part 311 is located in a first sub-gap A1 and extends along the extension direction of the first sub-gap A1. The second part 312 is located on one side of the first part 311 along the thickness direction of the light guide plate 2. The second part 312 extends out of the assembly space through an opening on the back plate 1. Multiple light sources 32 are located on the side of the first part 311 facing the light guide plate 2. The connector 33 is located in the second part 312.

[0117] Wherein, the light source 32 on the first part 311 of the substrate 31 can be connected with the connector 33 on the second part 312 of the substrate 31, the connector 33 can follow the second part 312 to extend out of the assembly space and be connected with the main control board of the display device, and the through hole can control the light-emitting state of the light source 32 on the light bar 3.

[0118] Wherein, the second part 312 of the substrate 31 extends out of the assembly space through the hole on the back plate 1, the hole can be arranged on the bottom plate 11 or also can be arranged on the side plate 12, which is not limited here and is determined according to the actual situation.

[0119] Wherein, the light source 32 can be a LED light source, one side of the light bar 3 with the light source 32 is the light-emitting side of the light bar 3, and the side of the light bar 3 away from the light source 32 is the non-light-emitting side of the light bar 3; the substrate 31 can be an aluminum substrate.

[0120] In the light bar 3, the first part 311 and the second part 312 of the substrate 31 are arranged along the thickness direction of the light guide plate 2, so that the distance between the light source 32 and the edge of the substrate 31 along the extension direction of the first sub-gap A1 can be small enough, the length of the part (first part) of the light bar 3 in the first gap can be short enough under the condition of ensuring the effective light-emitting area of the light guide plate 2, and then the first elastic member 41 with sufficient length can be arranged at both ends of the light bar 3, the contact area between the first elastic member 41 and the light guide plate 2 is increased, the compression amount of the first elastic member 41 is reduced, the position of the light guide plate 2 is prevented from changing greatly with the movement of the backlight module in the use direction, and the stability of the brightness of the display module during display is enhanced.

[0121] In the light bar, the distance between the light source 32 at the end of the first part 311 of the substrate 31 and the edge of the substrate 31 can be limited to 0.5mm, and the total length of the substrate 31 along the extension direction of the first part 311 can be 1mm longer than the total length of the plurality of light sources 32 arranged.

[0122] In actual application, the backlight module of the above-mentioned 21.5inch display device is taken as an example, such as Figure 7As shown, the limit size d5 of the distance from the light source 32 at the end of the light bar 3 to the edge of the substrate 31 is 0.5 mm, the light emitting angle of the light source 32 is 60°, and the light exit surface of the light guide plate 2 can be divided into an effective light exit area B1 and a non-effective light exit area B2 surrounding the effective light exit area. When the edge of the effective light exit area B1 extending in the width direction of the light guide plate 2 falls within the light emitting surface of the light source 32 at the end of the light bar 3, the display picture will not have display problems such as dark shadows. Therefore, the position of the light source 32 at the end of the light bar 3 corresponds to the effective light exit area B1 of the light guide plate 2, and the distance between the light source 32 at the end of the light bar 3 and the edge of the effective light exit area B1 extending in the width direction can be set as d6=1.15 mm. According to the design requirements, the limit value of the edge of the light guide plate 2 extending in the width direction to the effective light exit area B1 can be d7=3.7 mm, that is, the distance between the end of the light bar 3 and the edge of the light guide plate 2 extending in the width direction is d6+d7=4.85 mm, which is much larger than the required length of 3.9 mm of the first elastic member 41. At this time, it is not necessary to increase the width of the non-effective light exit area B2 of the light guide plate 2 due to the design of the first elastic member 41, that is, it is not necessary to increase the width of the frame area of the display module, and the second elastic member 42 can also not be set.

[0123] In actual application, taking the backlight module of the above 21.5 inch display device as an example, the light source 32 can adopt a high light efficiency 4014 packaged LED lamp bead, 68*2 lamp beads are adopted, the substrate 31 adopts an aluminum substrate with a length of 477.4 mm, a width of 4.8 mm, a thickness of 1.0 mm, and a heat dissipation coefficient of 1 W / m*K, the driving condition of the lamp bead is 76 mA, the light efficiency of a single lamp bead is 118.5 lm / W, and the light bar 3 can provide a light flux of 27 lm*68*2 ea=3672 lm. The light guide plate can ensure the required brightness energy of the display module.

[0124] The backlight module provided by the embodiment of the present application comprises Figure 8 As shown, the plurality of elastic members 4 further comprise third elastic members 43 located at two ends of the second sub-gap A2, and the third elastic members 43 can position the light guide plate 2 in the gap without the light bar 3. For example, the first elastic member 41 and / or the second elastic member 42 can position the light guide plate in the width direction of the light guide plate, and the third elastic member 43 can position the light guide plate in the length direction of the light guide plate.

[0125] The backlight module can provide assembly space by compressing the elastic members 4 around the light guide plate 2 during assembly of the light guide plate 2, and can provide sufficient expansion space by compressing the elastic members 4 after the light guide plate 2 is assembled in place, so that the elastic members 4 can automatically adjust back to consistent stress, achieve a state in which the first gaps A are evenly distributed around the light guide plate, and the position of the light guide plate 2 does not change significantly due to changes in the use direction of the backlight module and other activities, so that the light efficiency of the light source on the light bar does not change significantly, thereby avoiding floating differences in brightness at the same position during display of the display module, and ensuring the stability of the display brightness.

[0126] As shown in Figure 9 , at the corner of the intersecting first sub-gap A1 and second sub-gap A2, the third elastic member 43 and the first elastic member 41 can be connected to each other, which can better limit the light guide plate 2 by the elastic member.

[0127] Meanwhile, if there are two intersecting first sub-gaps in the backlight module, the two first elastic members at the corner of the two intersecting first sub-gaps can also be connected to each other; if there are two intersecting second sub-gaps in the backlight module, the two third elastic members at the corner of the two intersecting second sub-gaps can also be connected to each other.

[0128] Specifically, as shown in Figure 9 , of the intersecting third elastic member 43 and first elastic member 41, the length l2 of the third elastic member 43 along the extension direction of the first gap A in which it is located is greater than the length l1 of the first elastic member 41 along the extension direction of the first gap A in which it is located. That is, at the corner of the two first gaps A, the two connected elastic members can be in the shape of "L", which can strengthen the limiting effect on the light guide plate 2 by lengthening the third elastic member 43 in the first gap A of the light bar 3.

[0129] Specifically, the shapes of the structures in which each third elastic member 43 intersects the first elastic member 41 can be different, which can distinguish different positions by observing the different shapes of the elastic members during assembly of the backlight module, and prevent incorrect assembly.

[0130] As shown in Figure 10 , the plurality of elastic members 4 can also include a fourth elastic member 44 located in the middle region of the second sub-gap A2, which can reduce the compression amount of the elastic member by the light guide plate 2 by increasing the contact area between the elastic member (third elastic member 43 and fourth elastic member 44) in the second sub-gap A2 of the light bar 3 and the light guide plate 2, avoid movement of the light guide plate 2, and strengthen the limiting effect on the light guide plate 2.

[0131] In the embodiment of the present application, the assembling space of the light guide plate is provided by compressing the elastic member 4 around, and the thickness of the elastic member along the width direction of the first gap in the natural stretched state is greater than the width of the first gap. The thickness of the elastic member 4 along the width direction of the first gap is mainly determined by the expansion space required by the light guide plate 2. Specifically, the sum of the thicknesses of the two opposite elastic members 4 along the width direction of the first gap × the compression ratio of the elastic member 4 > the sum of the widths of the two opposite first gaps, which can ensure that the compressible amount of the elastic member 4 is sufficient, wherein the sum of the widths of the two opposite first gaps is greater than the expansion amount of the light guide plate in the arrangement direction of the two opposite first gaps.

[0132] For example, as shown in the side-in light backlight module, Figure 8 the elastic member 4 is arranged in each first gap, and the thickness of the elastic member 4 along the width direction of the first gap is mainly determined by the expansion space required by the light guide plate 2. It needs to meet: the sum of the thicknesses of the two opposite elastic members 4 along the length direction of the light guide plate 2 × the compression ratio of the elastic member 4 > the expansion space of the light guide plate 2 along the length direction, the expansion space of the light guide plate 2 along the length direction is the sum of the widths of the two first gaps arranged along the length direction, which is greater than the expansion amount of the light guide plate 2 along the length direction; the sum of the thicknesses of the two opposite elastic members 4 along the width direction of the light guide plate 2 × the compression ratio of the elastic member 4 > the expansion space of the light guide plate 2 along the width direction, the expansion space of the light guide plate 2 along the width direction is the sum of the widths of the two first gaps arranged along the width direction, which is greater than the expansion amount of the light guide plate 2 along the width direction. The expansion space of the light guide plate 2 along the length direction and the width direction can be a predetermined value, which is determined according to the actual situation. The expansion amount of the light guide plate 2 = the length or width of the light guide plate 2 × the temperature difference × the expansion coefficient + the manufacturing tolerance.

[0133] In practical application, taking the backlight module of the above-mentioned 21.5 inch display device as an example, the expansion space length (H) / width (V) of the light guide plate 2 can be set as 1.0 mm / 0.85 mm respectively. If the compression ratio of the elastic member 4 is 40%, the thickness of the two opposite elastic members 4 along the length direction of the light guide plate 2 in the backlight module can be designed as 3 mm, and the thickness of the two opposite elastic members 4 along the width direction of the light guide plate 2 can be designed as 2.3 mm. Then the compressible space length direction in the backlight module can be 3 × 2 × 0.4 = 2.4 mm, and the width direction can be 2.3 × 2 × 0.4 = 1.84 mm, which can meet the use of the light guide plate 2.

[0134] In the embodiment of the present application, as shown in Figure 2As shown in the figure, the distance d1 from the surface of the elastic member 4 away from the bottom plate 11 to the first plane is less than or equal to the distance d2 from the surface of the light guide plate 2 away from the bottom plate 11 to the first plane, the first plane is the plane where the surface of the light guide plate 2 faces the bottom plate 11, and d2 is the thickness of the light guide plate 2, which can avoid interference of the elastic member 4 to other films or other structures above the light guide plate 2.

[0135] In the embodiment of the present application, as shown in the figure, Figure 11 As shown in the figure, the area near the light guide plate on the side of the elastic member away from the bottom plate can be designed with a cut angle, and in the process of assembling the light guide plate, the slope of the cut angle 48 on the elastic member 4 can facilitate the light guide plate 2 to be installed into the area surrounded by the elastic member 4. Optionally, the inclination angle of the slope of the cut angle 48 can be between 30° and 70°, for example, the inclination angle of the slope of the cut angle 48 can be 45°.

[0136] In the embodiment of the present application, the material of the elastic member 4 can be rubber material or other materials, which is not limited here and is determined according to the actual situation. For example, the material of the elastic member 4 can be a silicone pad material with a Shore hardness of 70 degrees and a compression ratio of 40%.

[0137] In the embodiment of the present application, as shown in the figure, Figure 12 As shown in the figure, the backlight module can further include an adhesive 6 located in the middle area of the second sub-gap A2, and the side surface 21 of the light guide plate 2 is adhered to the side plate 12 through the adhesive 6, which can fix the position of the light guide plate 2 in the backlight module through the adhesive 6. After the light guide plate 2 is fixed through the adhesive 6, when the placement direction of the module changes, the light guide plate 2 will not be displaced due to gravity, the relative position of the light guide plate 2 and the light bar 3 will not change, and the light brightness of the same position of the light guide plate 2 will not change, which can improve the display brightness stability of the display module. On the other hand, the light guide plate 2 is fixed by the adhesive 6, the adhesive 6 is pasted on the back plate 1 and the light guide plate 2, and when the light guide plate 2 expands, the expansion space can be provided by compressing the adhesive 6, which will not be affected by the length of the light guide plate 2 to cause fixation, and the light guide plate 2 will not be displaced during transportation or vibration, and the mechanical reliability is better.

[0138] Specifically, in the second sub-gap, the adhesive 6 can be in a compressed state under the action of the light guide plate 2 and the side plate 12, and the adhesive 6 is pasted well between the light guide plate 2 and the back plate 1 through compression, and will not occur the phenomenon of opening. For example, when the light guide plate 2 is initially assembled in the back plate 1, the compression amount of the adhesive 6 can be 0.2mm.

[0139] In addition, as shown in the figure, Figure 13As shown, the distance d3 from the surface of the adhesive 6 away from the bottom plate 11 to the first plane is less than or equal to the distance d4 from the surface of the light guide plate 2 away from the bottom plate 11 to the first plane, the first plane being the plane where the surface of the light guide plate 2 faces the bottom plate 11, and d4 being the thickness of the light guide plate 2, so that the adhesive 6 does not interfere with other films or other structures above the light guide plate 2, for example, the height of the adhesive 6 can be 0.2mm lower than the height of the light guide plate 2.

[0140] In the above embodiment, the adhesive 6 can be a double-sided foam tape. The compression ratio of the double-sided foam tape can be 50%, which can provide expansion space for the light guide plate 2 during expansion.

[0141] For example, in the backlight module of a 21.5-inch and 27-inch display device, the length of the adhesive 6 can be designed to be 100mm, the thickness in the width direction of the second sub-gap can be 3.2mm, and the compression ratio of the adhesive 6 can be 50%, which can provide expansion space for the light guide plate 2 during expansion.

[0142] In the above embodiment, as shown, Figure 14 The backlight module further includes a white reflective sheet 7 between the light guide plate 2 and the bottom plate 11, which can reflect the light emitted by the light guide plate 2 towards the bottom plate 11 back into the light guide plate 2. When the white reflective sheet 7 is arranged, the elastic member 4 and the adhesive 6 need to be avoided to avoid interference between the white reflective sheet 7 and the elastic member 4 and the adhesive 6. As shown, Figure 13 The backlight module further includes an optical film 8 on the side of the light guide plate 2 away from the bottom plate 11, which can improve the light output effect of the backlight module.

[0143] Specifically, as shown, Figure 14 The bottom plate 11 is provided with a reinforcing rib 112 near the side plate 12, the reinforcing rib 112 protrudes towards the side of the bottom plate 11 away from the light guide plate 2, and the side of the reinforcing rib 112 towards the light guide plate 2 is provided with a reinforcing rib groove 113; in order to prevent the white reflective sheet 7 from being trapped in the reinforcing rib groove 113, the backlight module further includes a bottom pad 45 in the reinforcing rib groove 113, the white reflective sheet 7 is located between the bottom pad 45 and the light guide plate 2, the bottom pad 45 abuts against the white reflective sheet 7, and the bottom pad 45 can support and fix the position of the white reflective sheet 7.

[0144] Specifically, the bottom pad 45 can be integrally formed with the elastic member 4. For example, the bottom pad 45 can be arranged at the corner of the back plate 1, the material of the bottom pad 45 and the material of the elastic member can be the same, and the bottom pad 45 can be integrally formed with the first elastic member 41 and the third elastic member 43 in the first gap, as shown, Figure 15 The bottom pad 45 can strengthen the mechanical strength of the backlight module.

[0145] In the above embodiment, as shown, Figure 16As shown in the figure, the surface of the light guide plate 2 away from the bottom plate 11 is a prism structure 22, which can gather stray light incident to the light guide plate 2 from the light source 32, and converge the light angle, thereby improving the light efficiency of the light guide plate 2.

[0146] Specifically, as shown in the figure, Figure 16 The top angle of the prism in the prism structure 22 of the surface of the light guide plate 2 away from the bottom plate 11 is in an arc shape, which can increase the scratch resistance of the light guide plate 2 and provide mechanical stability for the backlight module.

[0147] Specifically, as shown in the figure, Figure 16 The optical film 8 includes a lower prism film 81, an upper prism film 82, and a reflective polarized brightness enhancement film 83. The lower prism film 81 is located on the side of the light guide plate 2 away from the bottom plate 11, the upper prism film 82 is located on the side of the lower prism film 81 away from the bottom plate 11, and the polarized brightness enhancement film 83 is located on the side of the upper prism film 82 away from the lower prism film 81. The prism structure 22 on the light guide plate 2 has a plurality of first prisms extending in a first direction, the lower prism film 81 has a plurality of second prisms extending in a second direction, the upper prism film 82 has a plurality of third prisms extending in the first direction, and the first direction is perpendicular to the second direction. The first direction can be any direction, as long as it is perpendicular to the second direction. In actual application, in order to facilitate production, when the light exit surface of the light guide plate is rectangular, the first direction can be the length direction of the light guide plate 2, and the second direction can be the width direction of the light guide plate.

[0148] If the extension direction of the first prisms in the prism structure 22 of the light guide plate 2 is set to be horizontal 0°, the extension direction of the second prisms of the lower prism film 81 is 90°, and the extension direction of the third prisms of the upper prism film 82 is 0°, which can further converge the horizontal and vertical stray light through the crossed prisms, thereby improving the light efficiency of the module in the direction perpendicular to the light exit surface of the light guide plate 2.

[0149] The reflective polarized brightness enhancement film 83 can recycle the light emitted by the upper prism film 82, thereby greatly improving the brightness of the backlight module.

[0150] In actual application, as shown in the figure, Figure 17As shown, the inclined surfaces R of the prisms of the prism structure 22 of the light guide plate 2, the lower prism film 81 and the upper prism film 82 form the light emitting surface, light enters the prisms from the light entering surface of the prisms, and first refraction occurs, and then the light is emitted from the inclined surface of the prisms, and second refraction occurs, and the angle between the light and the vertical surface is changed through the inclined surface of the prisms, the angle of the emitted light is reduced and gathered in the middle, the light flux at a large viewing angle is reduced according to the law of conservation of energy, the light flux in the display viewing angle range is increased, and the brightness of the picture is improved. Since the gathering occurs at the inclined surface of the prisms, the light gathering direction is related to the extension direction of the prisms, that is, the brightness improvement is related to the angle of the prisms. For example, the 0° horizontal prisms gather the backlight module to emit light in the up-down direction, the 90° vertical prisms gather the backlight module to emit light in the left-right direction, and the mutually perpendicular directions can be combined into light of any angle according to different intensities. Therefore, the two prisms of the prism film with the extension directions perpendicular to each other can satisfy the light gathering of the front emitted light of the backlight module, that is, the light efficiency is best. Through comparison with the film material without prisms, the light efficiency of the upper and lower prisms is 1.25 times, and the light efficiency of the reflective polarizing brightness enhancement film 83 is 1.4 times. The above optical film material 8 can improve the light efficiency of the display module by about 2.2 times.

[0151] In the embodiment of the present application, the backlight module further includes a middle frame, the middle frame includes a fixed part surrounding the light guide plate and a window part located on the side of the optical film material away from the bottom plate, the fixed part is fixedly connected with the side plate, and the window part has a window corresponding to the effective light emitting area of the light guide plate.

[0152] In the embodiment of the present application, in order to avoid the movement of the optical film material 8, the optical film material 8 needs to be limited. Specifically, the edges of the film layers in the optical film material 8 have a plurality of extension parts, and the side plate of the back plate or the fixed part of the middle frame or the elastic member has a plurality of positioning parts, each positioning part is opposite to one extension part, and the optical film material can be positioned by cooperating the extension part with the corresponding positioning part on the side plate or the fixed part or the elastic member. Among them, the above optical film material can include a plurality of film layers, for example, including the above-mentioned lower prism film 81, the upper prism film 82 and the reflective polarizing brightness enhancement film 83, etc.

[0153] In one embodiment, as shown in Figure 18 The side of the elastic member 4 away from the bottom plate can have a stepped positioning part 46 opposite to the extension part 84, the stepped positioning part 46 has at least one stepped surface 461, and the extension part 84 on each film layer of the optical film material 8 is lapped on the stepped surface 461, so that the stepped positioning part 46 can limit each film layer of the optical film material 8 towards the side wall of the optical film material 8.

[0154] Specifically, the stepped positioning part 46 can have a plurality of stepped surfaces 461, for example, as shown in Figure 19As shown, the stepped positioning portion 46 can include a first stepped surface a, a second stepped surface b and a third stepped surface c, corresponding to the lower prism film 81, the upper prism film 82 and the reflective polarized brightening film 83 of the optical film material 8 respectively, the extensions on the lower prism film 81 correspond to the first stepped surface a, the extensions on the upper prism film 82 correspond to the second stepped surface b, and the extensions on the reflective polarized brightening film 83 correspond to the third stepped surface c. Alternatively, the stepped positioning portion 46 can also have one stepped surface 461, which is flush with the surface of the optical film material 8 facing the bottom plate, and the extensions 84 of each film layer of the optical film material 8 are arranged on the stepped surface 461. The extensions 84 of each film layer of the optical film material 8 and the sidewall of the stepped positioning portion 46 facing the optical film material 8 have a gap therebetween, which provides a swelling space for the optical film material to swell.

[0155] In an embodiment, as shown, the side of the elastic member 4 away from the bottom plate can have a protruding positioning portion 47 cooperating with the extensions 84, and the extensions 84 have a first insertion hole 841 cooperating with the protruding positioning portion 47, and the protruding positioning portion 47 is inserted into the first insertion hole 841. Specifically, the sidewall of the protruding positioning portion 47 and the sidewall of the first insertion hole 841 can have a gap therebetween, which provides a swelling space for the optical film material to swell. Figure 20 Specifically, the film layers in the optical film material 8 can have opposite first and second edges, and the first and second edges can have extensions 84 thereon, and the number of extensions 84 on each edge is not limited and can be determined according to actual conditions. The side of the elastic member 4 opposite to the first edge and the side of the elastic member 4 opposite to the second edge can have a stepped positioning portion 46, so that the film layers in the optical film material 8 can be positioned by the stepped positioning portion 46 in the direction in which the first and second edges are arranged, thereby preventing the optical film material 8 from moving; or the side of the elastic member 4 opposite to the first edge and the side of the elastic member 4 opposite to the second edge can have a protruding positioning portion 47, so that the film layers in the optical film material 8 can be positioned by the protruding positioning portion 47, thereby preventing the optical film material 8 from moving; or the side of the elastic member 4 opposite to the first edge can have a stepped positioning portion 46, and the side of the elastic member 4 opposite to the second edge can have a protruding positioning portion 47, so that the film layers in the optical film material 8 can be positioned by the cooperation of the stepped positioning portion 46 and the protruding positioning portion 47; or the stepped surface 461 of the stepped positioning portion 47 can have a protruding positioning portion 47 thereon, and the extensions 84 of the film layers in the optical film material 8 are arranged on the stepped surface 461 and cooperate with the protruding positioning portion 47 on the stepped surface 461.

[0156]

[0157] ​The shape of the film layer in the optical film material 8 matches the shape of the light guide plate 2. If the shape of the optical film material 8 is rectangular, the first edge and the second edge can be the two opposite short edges of the film layer in the optical film material 8, or can be the two opposite long edges, which is not limited here. For example, the two opposite short edges of the optical film material 8 have the extension part 84, and the third elastic member 43 and / or the fourth elastic member 44 opposite in the length direction of the light guide plate 2 can have the positioning part, and the optical film material 8 is positioned by the positioning part on the third elastic member 43 and / or the fourth elastic member 44; or the two opposite long edges of the optical film material 8 have the extension part 84, and the two opposite first elastic members 41 in the width direction of the light guide plate 2 can have the positioning part, and the optical film material 8 is positioned by the positioning part on the first elastic member 41; or the opposite short edges and the opposite long edges of the optical film material 8 both have the extension part 84, and the third elastic member 43, the fourth elastic member 44 and the first elastic member 41 can all be provided with the positioning part.

[0158] In the embodiment of the present application, as shown in Figure 21 and Figure 22 , the film layer in the optical film material 8 has the opposite first edge e1 and the second edge e2, and the first edge e1 can have at least one first extension part 842, and the first extension part 842 has a second insertion hole 8421; as shown in Figure 23 , the second edge e2 of the film layer in the optical film material 8 has at least one second extension part 843, and the second extension part corresponds to the first extension part one by one; at the same time, as shown in Figure 24 and Figure 25 , the side plate 12 away from the bottom plate 11 has a first positioning part matched with the first extension part 842, and the first positioning part includes a first recessed groove 113 and a boss 114 at the bottom of the first recessed groove 113, and the first extension part 84 is located in the first recessed groove 113, and the boss 114 is inserted into the second insertion hole 8421; at the same time, as shown in Figure 26 and Figure 27 , the side plate 12 away from the bottom plate 11 has a second positioning part matched with the second extension part 843, and the second positioning part includes a second recessed groove 115, and the second extension part 843 is located in the second recessed groove 115. Alternatively, the first recessed groove, the boss and the second recessed groove can also be provided on the fixed part of the middle frame, which is not limited here and is determined according to the actual situation.

[0159] In the aforementioned backlight module, the first extension 842 cooperates with the first recess 113, and the second extension 843 cooperates with the second recess 115 to limit the optical film 8 in the extension direction of the first edge e1 and the second edge e2. The second insertion hole 8421 cooperates with the boss 114 to limit the optical film 8 in the arrangement direction of the first edge e1 and the second edge e2. Through the cooperation of the first extension 842 with the first positioning part and the cooperation of the second extension 843 with the second positioning part, the optical film 8 can be limited in two directions at the same time.

[0160] Specifically, due to the assembly error, manufacturing error, and the need for expansion space of the optical film material, the two sidewalls of the first extension 842 arranged along the extension direction of the first edge e1 can have a third gap D1 between them and the sidewall of the first recess 113. The two sidewalls of the second insertion hole 8421 arranged along the arrangement direction of the first edge e1 and the second edge e2 can have a fourth gap D2 between them and the sidewall of the boss 114. The two sidewalls of the second extension 843 arranged along the extension direction of the second edge e2 can have a fifth gap D3 between them and the sidewall of the second recess 115. The width of the fifth gap D3 is equal to the width of the third gap D1. The second edge e2 and the side plate 12 where the second recess 115 is located have a sixth gap D4.

[0161] Specifically, the first edge e1 may have two first extensions 842, and the second edge may have two second extensions 843. Each second extension 843 is respectively disposed opposite to a first extension 842. The third, fourth, and fifth gaps formed by a set of opposite first and second extensions with the side plate or fixing part are smaller than the third, fourth, and fifth gaps formed by another set of first and second extensions with the side plate or fixing part, which can achieve a combination of fine positioning and coarse positioning.

[0162] In practical applications, such as Figures 21 to 27 As shown, the first edge e1 of the optical film material 8 extending along the width direction of the light guide plate 2 has two first extensions 842 arranged vertically, and the second edge e2 has two second extensions 843 arranged vertically. The upper set of opposing first extensions 842 and second extensions 843 can achieve fine positioning, while the lower set of first extensions 842 and second extensions 843 can achieve coarse positioning. The expansion process of the optical film material is from the fine positioning point outwards. Through the coarse positioning part, sufficient expansion gap can be provided during the expansion process of the optical film material to ensure the flatness of the optical film material.

[0163] Taking the backlight module of the aforementioned 21.5-inch display device as an example, the dimensional data of the prism film and the incremental film in the optical film material can be shown in Table 2.

[0164] Table 2

[0165]

[0166] According to the above data, as shown in Figure 21 , Figure 25 , Figure 27 The manufacturing tolerance of the second insertion hole 8421 is ±0.1mm, and the wall thickness tolerance of the boss 114 is ±0.05mm. Considering the tolerance, the width of the second insertion hole 8421 is designed to be 0.15mm larger than the wall thickness of the boss 114 on one side, that is, the fourth gap D2 is 0.15mm. Therefore, the wall thickness of the boss 114 can be set to 1.5mm, and the width of the second insertion hole 8421 can be designed to be 1.8mm. Through the cooperation of the second insertion hole 8421 and the boss 114, the movement of the optical film material in the long direction of the light guide plate is limited. When the optical film material expands, it extends from the left first extension 842 to the right. A large enough expansion gap, that is, the sixth gap D4, needs to be reserved between the right side of the optical film material and the side plate 12 according to the expansion condition. According to the calculation in Table 2 above, the maximum requirement for the sixth gap D4 is 1.53mm. In actual application, the sixth gap D4 can be designed to be 1.65mm. Specifically, in the structure of the first extension and the second extension of the fine positioning, the width of the third gap D1 and the fifth gap D3 can be set to D1=D3=0.15mm. In the structure of the first extension and the second extension of the coarse positioning, the size of each positioning gap can be determined according to the actual situation, which is not limited here. In the backlight module, the optical film material expands from the fine positioning to both sides. According to the expansion condition, a large enough expansion gap needs to be reserved between the optical film material and the back plate, the middle frame and other structures. According to the data in Table 2 above, the expansion space reserved between the edge of the optical film material and the back plate, the middle frame and other structures can be 1.0mm. Therefore, the total expansion space of both sides of the optical film material is 2.0mm, which can meet the expansion requirement.

[0167] The present application also provides a display module, comprising the backlight module provided in the technical solutions above and a display panel located at the light emitting side of the backlight module.

[0168] Specifically, the display panel can be located at the side of the window part of the middle frame away from the bottom plate.

[0169] The present application also provides a display device, comprising the display module provided in the technical solutions above.

[0170] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A backlight module, wherein, include: The back panel includes a bottom plate and a plurality of side plates arranged around the bottom plate, the plurality of side plates and the bottom plate forming an assembly space; A light guide plate is located within the assembly space. The light guide plate includes multiple sides, each side being disposed opposite to a side plate, and each side having a first gap with the opposite side plate. At least two light strips are provided, each of which is disposed in a different first gap. The light-emitting side of each light strip is opposite to the side of the light guide plate. The first gap with the light strip is a first sub-gap, and the first gap without the light strip is a second sub-gap. Multiple elastic elements, at least some of which are located within each of the first sub-gap; The plurality of elastic elements includes first elastic elements located at both ends of each of the first sub-gap; in the first sub-gap, the light strip is located between two of the first elastic elements; It also includes a white reflective sheet located between the light guide plate and the base plate; The base plate has a reinforcing rib in the area near the side plate. The reinforcing rib protrudes toward the side of the base plate away from the light guide plate, and a reinforcing rib groove is formed on the side of the reinforcing rib toward the light guide plate. The backlight module also includes a base pad located within the reinforcing rib groove, and the white reflective sheet is located between the base pad and the light guide plate, with the base pad abutting against the white reflective sheet; The base pad and the elastic element are integrally formed.

2. The backlight module according to claim 1, wherein, a length of the elastic member in an extension direction of the first sub-gap along which the elastic member is located l satisfies: wherein, F n is a force size of the elastic member during compression, E is a tensile strength of the elastic member, Δ l is a compression amount of the elastic member after being subjected to force, l 0 is a thickness of the elastic member in a width direction of the first sub-gap along which the elastic member is located, h is a thickness of a portion where the elastic member contacts the light guide plate in a thickness direction of the light guide plate.

3. The backlight module according to claim 1 or 2, wherein, In the first sub-gap, the non-light-emitting side of the light strip is fixedly connected to the side plate, and there is a second gap between the light-emitting side of the light strip and the side of the light guide plate.

4. The backlight module according to claim 1 or 2, wherein, It also includes a heat dissipation plate that contacts the base plate, the heat dissipation plate including a first heat dissipation part located between the non-light-emitting side of the light strip and the side plate; The non-light-emitting side of the light strip is bonded to the first heat dissipation part, and the light-emitting side of the light strip abuts against the side of the light guide plate; The plurality of elastic elements includes at least one second elastic element located between the first heat dissipation portion and the side plate.

5. The backlight module according to claim 4, wherein, The heat sink also includes a second heat sink portion that contacts the base plate; The base plate has a clearance groove on the side facing the light guide plate, which is opposite to the second heat dissipation part, and the second heat dissipation part is slidably in contact with the bottom of the clearance groove.

6. The backlight module according to claim 4 or 5, wherein, The light-emitting side of the light strip has a transparent protective structure that abuts against the side of the light guide plate.

7. The backlight module according to any one of claims 1-6, wherein, The light strip includes a substrate, multiple light sources, and a connector. The substrate includes a first part and a second part. The first part is located in a first sub-gap and extends along the extension direction of the first sub-gap. The second part is located on one side of the first part along the thickness direction of the light guide plate. The second part extends out of the assembly space through an opening on the back plate. The multiple light sources are located on the side of the first part facing the light guide plate. The connector is located in the second part.

8. The backlight module according to any one of claims 1-7, wherein, The plurality of elastic elements also include a third elastic element located at both ends of the second sub-gap.

9. The backlight module according to claim 8, wherein, At the corner where the first sub-gap and the second sub-gap intersect, the third elastic element is connected to the first elastic element.

10. The backlight module according to claim 9, wherein, In the intersecting third elastic member and the first elastic member, the length of the third elastic member along the extension direction of the first gap in which it is located is greater than the length of the first elastic member along the extension direction of the first gap in which it is located.

11. The backlight module according to claim 9 or 10, wherein, The shapes of the structures where the third elastic element intersects with the first elastic element are different.

12. The backlight module according to any one of claims 1-11, wherein, The plurality of elastic elements also includes a fourth elastic element located in the middle region of the second sub-gap.

13. The backlight module according to any one of claims 1-12, wherein, When the elastic element is in its naturally extended state, its thickness along the width direction of the first gap is greater than the width of the first gap. The sum of the widths of the two opposing first gaps is greater than the expansion of the light guide plate in the direction in which the two opposing first gaps are arranged.

14. The backlight module according to any one of claims 1-13, wherein, The distance between the surface of the elastic element away from the base plate and the first plane is less than or equal to the distance between the surface of the light guide plate away from the base plate and the first plane, where the first plane is the plane on which the surface of the light guide plate faces the base plate.

15. The backlight module according to any one of claims 1-14, wherein, The elastic element is made of rubber.

16. The backlight module according to any one of claims 1-15, wherein, It also includes an adhesive component located in the middle region of the second sub-gap, through which the side of the light guide plate is bonded to the side plate.

17. The backlight module according to claim 16, wherein, In the second sub-gap, the adhesive is in a compressed state under the action of the light guide plate and the side plate.

18. The backlight module according to claim 16 or 17, wherein, The adhesive component is foam double-sided tape.

19. The backlight module according to any one of claims 1-18, wherein, The plurality of said sides include two opposing first sides and two opposing second sides, the first sides being adjacent to the second sides, and the length of the first side being greater than the length of the second side; At least two of the light strips include a first light strip and a second light strip respectively located in the first gap between the two first sides and the corresponding side plates, wherein the distance of the first light strip from the light guide plate is equal to the distance of the second light strip from the light guide plate.

20. The backlight module according to any one of claims 1-19, wherein, It also includes an optical film material located on the side of the light guide plate away from the base plate.

21. The backlight module according to claim 20, wherein, The surface of the light guide plate away from the base plate has a prism structure.

22. The backlight module according to claim 21, wherein, The prism in the prism structure on the surface of the light guide plate away from the base plate has a rounded apex.

23. The backlight module according to claim 21 or 22, wherein, The optical film material includes a lower prism film, an upper prism film, and a reflective polarizing brightness enhancement film. The lower prism film is located on the side of the light guide plate away from the base plate, the upper prism film is located on the side of the lower prism film away from the base plate, and the polarizing brightness enhancement film is located on the side of the upper prism film away from the lower prism film. The prism structure on the light guide plate has a plurality of first prisms arranged side by side extending along a first direction, the lower prism film has a plurality of second prisms arranged side by side extending along a second direction, and the upper prism film has a plurality of third prisms arranged side by side extending along a first direction, wherein the first direction is perpendicular to the second direction.

24. The backlight module according to any one of claims 20-23, wherein, It also includes a middle frame, which includes a fixing part surrounding the light guide plate and a window part located on the side of the optical film away from the base plate. The fixing part is fixedly connected to the side plate, and the window part has a window corresponding to the effective light emission area of ​​the light guide plate.

25. The backlight module according to claim 24, wherein, The edge of the film layer in the optical film material has multiple extensions, and the side plate, the fixing part, or the elastic member has multiple positioning parts. Each positioning part is opposite to one of the extensions, and the optical film material is positioned by the cooperation of the extensions with the corresponding positioning parts on the side plate, the fixing part, or the elastic member.

26. The backlight module according to claim 25, wherein, The elastic member has a stepped positioning portion on the side away from the base plate that is opposite to the extension portion. The stepped positioning portion has at least one stepped surface, and the extension portions on each film layer of the optical film material rest on the stepped surface.

27. The backlight module according to claim 26, wherein, The stepped positioning part has a stepped surface, which is flush with the surface of the optical film material facing the base plate, and the extensions on each film layer of the optical film material rest on the stepped surface. or, The stepped positioning part has multiple stepped surfaces, and each of the multiple stepped surfaces corresponds to and is flush with the surface of each film layer in the optical film material facing the base plate. The extensions on each film layer in the optical film material rest on the corresponding stepped surfaces.

28. The backlight module according to any one of claims 25-27, wherein, The elastic member has a protruding positioning part on the side away from the base plate that cooperates with the extension. The extension has a first insertion hole that cooperates with the protruding positioning part, and the protruding positioning part is inserted into the first insertion hole.

29. The backlight module according to claim 25, wherein, The film layer in the optical film material includes a first edge and a second edge, the first edge having at least one first extension, the first extension having a second insertion hole, the second edge having at least one second extension, and the second extension corresponding to the first extension one by one; The side plate or the fixing part away from the bottom plate has a first positioning part that cooperates with the first extension part. The first positioning part includes a first recess and a boss located at the bottom of the first recess. The first extension part is located in the first recess, and the boss is inserted into the second insertion hole. The side plate or the fixing part has a second positioning part that cooperates with the second extension on the side away from the bottom plate. The second positioning part includes a second sink groove, and the second extension is located in the second sink groove.

30. The backlight module according to claim 29, wherein, The two sidewalls of the first extension, arranged along the extension direction of the first edge, have a third gap with the sidewall of the first sink. The second insertion hole has a fourth gap between its two sidewalls, which are arranged along the direction of the first edge and the second edge, and the sidewall of the boss. The second extension has a fifth gap between the two sidewalls arranged along the extension direction of the second edge and the sidewall of the second sink, the width of the fifth gap being equal to the width of the third gap; There is a sixth gap between the second edge and the side plate where the second sink is located.

31. The backlight module according to claim 30, wherein, The first edge has two first extensions, and the second edge has two second extensions. Each second extension is disposed opposite to one of the first extensions. The third, fourth, and fifth gaps formed by a set of opposing first and second extensions with the side plate or the fixing part are smaller than the third, fourth, and fifth gaps formed by another set of opposing first and second extensions with the side plate or the fixing part.

32. A display module, wherein, It includes the backlight module as described in any one of claims 1-31 and the display panel located on the light-emitting side of the backlight module.

33. A display device, wherein, Includes the display module as described in claim 32.

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