Backlight module and display device

Abstract

The utility model relates to a backlight module and a display device, the backlight module comprises a light guide plate and an optical film group located on the light-emitting surface of the light guide plate, the optical film group comprises a diffusion sheet, a first prismatic lens, a second prismatic lens and a brightening film and / or a peep-proof film which are stacked, and the backlight module further comprises a first adhesive layer arranged between the diffusion sheet and the light guide plate, a second adhesive layer arranged between the diffusion sheet and the light guide plate, and a third adhesive layer arranged between the second prismatic lens and the second prismatic lens, the second bonding glue layer comprises a first sub bonding glue layer and a second sub bonding glue layer, the first sub bonding glue layer is bonded between the diffusion sheet and the first prismatic lens, the second sub bonding glue layer is bonded between the diffusion sheet and the second prismatic lens, and the first prismatic lens is provided with a first notch for avoiding the second sub bonding glue layer; the third adhesive layer comprises a third sub adhesive layer and a fourth sub adhesive layer, the third sub adhesive layer is adhered between the first prismatic lens and the brightening film or the peep-proof film, and the fourth sub adhesive layer is adhered between the second prismatic lens and the brightening film or the peep-proof film; and the second prismatic lens is provided with a second gap for avoiding the third sub adhesive layer.

Description

Technical Field

[0001] The utility model relates to the technical field of display product manufacturing, in particular to a backlight module and a display device. Background Art

[0002] As the size of the car ceiling screen is getting bigger and bigger, the backlight design of the ceiling screen module is also different from the conventional central control and instrument screen. The biggest design point that needs to be considered is the fixation of the optical film inside the backlight source. For some high-brightness products, which usually have a double prism structure, the structural fixation method will directly determine whether it can pass the conventional temperature cycle vibration test (three comprehensive test experiments). Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides a backlight module and a display device to solve the problem of bonding and fixing large-size optical films.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted in the embodiment of the utility model is: a backlight module, comprising a light guide plate and an optical film group located on the light emitting surface of the light guide plate, the optical film group comprising a diffusion sheet, a first prism sheet and a second prism sheet stacked in a direction away from the light guide plate, the optical film group also comprising a first adhesive layer, a second adhesive layer and a third adhesive layer;

[0005] The first adhesive layer is disposed between the diffusion sheet and the light guide plate;

[0006] The second adhesive layer includes a first sub-adhesive layer and a second sub-adhesive layer, the first sub-adhesive layer is bonded between the diffusion sheet and the first prism sheet, the second sub-adhesive layer is bonded between the diffusion sheet and the second prism sheet, and the first prism sheet is provided with a first notch for avoiding the second sub-adhesive layer;

[0007] The third adhesive layer includes a third sub-adhesive layer and a fourth sub-adhesive layer, the third sub-adhesive layer is bonded between the first prism sheet and the brightness enhancing film or the anti-peep film, the fourth sub-adhesive layer is bonded between the second prism sheet and the brightness enhancing film or the anti-peep film, and a second notch is provided on the second prism sheet for avoiding the third sub-adhesive layer.

[0008] Optionally, the first sub-adhesive layer and the second sub-adhesive layer are an integral structure.

[0009] Optionally, the third sub-adhesive layer and the fourth sub-adhesive layer are an integral structure.

[0010] Optionally, the orthographic projection of the first sub-adhesive layer on the light guide plate coincides with the orthographic projection of the third sub-adhesive layer on the light guide plate;

[0011] The orthographic projection of the second sub-adhesive layer on the light guide plate coincides with the orthographic projection of the fourth sub-adhesive layer on the light guide plate.

[0012] Optionally, in the light emitting direction of the light guide plate, the thickness of the second sub-adhesive layer is greater than the thickness of the first prism sheet;

[0013] In the light emitting direction of the light guide plate, the thickness of the third sub-adhesive layer is greater than the thickness of the second prism sheet.

[0014] Optionally, the first prism sheet includes a first edge, and in a length direction of the first edge, a portion of the first edge is concave to form the first notch;

[0015] The second prism sheet includes a second edge located on the same side as the first edge, and in the length direction of the second edge, a portion of the second edge is concave to form the second notch, and the orthographic projection of the first notch on the light guide plate is located on one side of the orthographic projection of the second notch on the light guide plate.

[0016] Optionally, the diffuser includes a third edge, and in the length direction of the third edge, the middle part of the third edge has a first area, the orthographic projection of the first adhesive layer on the diffuser is located in the first area, the orthographic projection of the second adhesive layer on the diffuser is located in the first area, and the orthographic projection of the third adhesive layer on the diffuser is located in the first area.

[0017] Optionally, in the length direction of the third edge, the length of the first region is 4 / 15-6 / 15 of the total length of the third edge.

[0018] Optionally, the optical film set further includes a brightness enhancement film and / or an anti-peep film stacked on a side of the second prism sheet away from the light guide plate.

[0019] Optionally, it further includes a rubber frame arranged around the light guide plate, the optical film group includes a first side and a second side arranged adjacent to each other, and the first side and the second side are both provided with a card slot to cooperate with the corresponding lugs on the rubber frame.

[0020] An embodiment of the utility model further provides a display device, comprising the above-mentioned backlight module.

[0021] The beneficial effects of the utility model are as follows: the diffuser and the light guide plate are fixedly bonded by a first adhesive layer of a single-layer adhesive structure, and the first prism sheet and the second prism sheet adopt a segmented high and low adhesive layer structure, that is, the setting of the second adhesive layer and the third adhesive layer can reduce the bonding length of the prism sheet while ensuring the bonding strength, thereby effectively preventing the wrinkle problem in the environmental reliability experiment caused by the large shrinkage rate of the prism sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram showing a backlight module in the related art;

[0023] Figure 2 A schematic diagram showing a backlight module in the related art;

[0024] Figure 3 A schematic diagram showing a backlight module in the related art;

[0025] Figure 4 A schematic diagram showing a backlight module in the related art;

[0026] Figure 5 A schematic diagram showing a backlight module in an embodiment of the present utility model;

[0027] Figure 6 express Figure 5 A magnified schematic diagram of part A;

[0028] Figure 7 express Figure 5 A magnified schematic diagram of part B;

[0029] Figure 8 express Figure 5 A magnified schematic diagram of part C;

[0030] Fig. 9 A schematic diagram showing the bonding state of the optical film set in the embodiment of the utility model;

[0031] Fig.10 A schematic diagram showing an optical film assembly in an embodiment of the utility model;

[0032] Fig.11 express Fig.10 An enlarged schematic diagram of the dotted box part. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0034] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] There are currently three mainstream bonding solutions for optical films of small and medium-sized automotive backlight sources: ① Single-layer adhesive segmented bonding (reference Figure 1 )②High and low glue segmented bonding (reference Figure 2 and Figure 3 ) and ③ single layer adhesive layer by layer (reference Figure 4 )Three types of fixation solutions.

[0036] refer to Figure 1 The first type is a single layer of double-sided adhesive bonded to the light guide plate 1 in sections, and a stepped boss 11 is set at the corresponding position of the light guide plate for bonding various optical films 2 in layers. This structure is mainly used for small and medium-sized products with large frame width on at least one side of the short side (generally COG glass instrument projects), because the bonding of optical films needs to ensure a certain bonding width. (Some early products also have steps on the light guide plate at the incident light measurement, but they are not widely used because they have bright edge problems on the screen.)

[0037] The second method is the high and low glue segmented bonding method, the core method of which is to bond the upper optical film 2 through the stepped bosses of the high and low glue. There are derivative changes for three optical films and four optical films respectively. Figure 2The three-sheet optical film structure uses high and low glue 3 to bond the upper and lower prism films. The four-sheet optical film structure uses two sections of high and low glue 3 to bond the diffusion & lower prism and the diffusion & upper prism respectively (the upper ALCF (anti-peep film) is separately bonded to the glue frame through the glue layer 4). This structural solution is mainly used on instrument display screens with narrow borders on the top / left / right sides, and the optical film is bonded and fixed through the ground side (generally, the ground side border is wider). The thickness difference of the high and low glue should not be too large, otherwise its bonding strength will not be enough to meet the needs of some customers with more stringent vibration conditions. Large displacement is prone to occur in the bonding thickness direction. Therefore, this solution for four optical films is usually only bonded to the third optical film from bottom to top, and the top optical film usually needs to be bonded to the bottom surface of the glue frame. Refer to Figure 3 Therefore, in order to meet more stringent experimental conditions, a third single-layer adhesive bonding solution was developed.

[0038] refer to Figure 4 The third bonding solution can ensure that the optical film has better bonding strength through a single layer of adhesive layer 3, but it is often used in small and medium sizes around 14.6 to 15.6" (total backlight length 300mm to 350mm). The reason is that the bonding and fixing area length of the optical film (reference Figure 4 When the length in the X direction is above 110mm, due to the dimensional shrinkage characteristics of the prism film after high temperature (the dimensional shrinkage of the 3M prism in the length direction (MD) is 0.29%, and the dimensional shrinkage in the width direction (TD) is 0.16%; the dimensional shrinkage of the DBEF (diffuser film) is measured at a maximum of 0.034%, and the size is relatively stable), it is easy to cause the risk of local wrinkles at the bonding position of the prism film; for small and medium-sized optical films, the length of the bonding area is 80 to 110mm, which can ensure that the bonding length accounts for nearly 1 / 3 of the total length of the film, and can ensure effective bonding strength.

[0039] refer to Figure 5-Figure 11 In view of the above problems, the present embodiment provides a backlight module, comprising a light guide plate 1 and an optical film group 2 located on the light emitting surface of the light guide plate 1, wherein the optical film group 2 comprises a diffusion sheet 21, a first prism sheet 22 and a second prism sheet 23 stacked in a direction away from the light guide plate 1, and the optical film group 2 further comprises a first adhesive layer 4, a second adhesive layer and a third adhesive layer 6;

[0040] The first adhesive layer 4 is disposed between the diffusion sheet 21 and the light guide plate 1;

[0041] The second adhesive layer 5 includes a first sub-adhesive layer 51 and a second sub-adhesive layer 52, wherein the first sub-adhesive layer 51 is bonded between the diffusion sheet 21 and the first prism sheet 22, and the second sub-adhesive layer 52 is bonded between the diffusion sheet 21 and the second prism sheet 23, and a first notch 2001 for avoiding the second sub-adhesive layer 52 is provided on the first prism sheet 22;

[0042] The third adhesive layer 6 includes a third sub-adhesive layer 61 and a fourth sub-adhesive layer 62, the third sub-adhesive layer 61 is bonded between the first prism sheet 22 and the brightness enhancement film 24 or the anti-peep film, the fourth sub-adhesive layer 62 is bonded between the second prism sheet 23 and the brightness enhancement film 24 or the anti-peep film, and a second notch 2002 for avoiding the third sub-adhesive layer 61 is provided on the second prism sheet 23.

[0043] refer to Fig. 9 The first adhesive layer 4, the second adhesive layer 5 and the third adhesive layer 6 are used to bond the optical films in the optical film group 2 layer by layer, and the second adhesive layer 5 and the third adhesive layer 6 used for bonding the first prism sheet 22 and the second prism sheet 23 are both segmented high and low adhesives. The second adhesive layer 5 is used to bond the diffuser 21 and the first prism sheet 22 and the second prism sheet 23. The third adhesive layer 6 is located on the side of the first prism sheet 22 and the second prism sheet 23 away from the light guide plate 1, so as to connect the first prism sheet 22 and the second prism sheet 23 with the brightness enhancement film 24 or the anti-peep film stacked on the side of the second prism sheet 23 away from the light guide plate 1.

[0044] The second adhesive layer 5 and the third adhesive layer 6 are both segmented high and low adhesive structures. Taking the second adhesive layer 5 as an example, in the first direction (reference Fig. 9In the X direction, the bonding area of ​​the second adhesive layer 5 is generally set at one side edge of the diffuser 21, and the first direction is the extension direction of the side edge. The bonding length of the second adhesive layer 5 is the sum of the bonding lengths of the first sub-adhesive layer 51 and the second sub-adhesive layer 52. The first prism sheet 22 is bonded and fixed by the first sub-adhesive layer 51, and the second prism sheet 23 is bonded and fixed by the second sub-adhesive layer 52, which improves the problem of wrinkles caused by shrinkage of the prism film due to excessive bonding length and ensures the bonding strength. The bonding lengths of the first sub-adhesive layer 51 and the second sub-adhesive layer 52 are set to 100mm, and the total bonding length of the second adhesive layer 5 is 200mm. According to the bonding length of the second adhesive layer accounting for 1 / 3 of the total length of the first prism sheet 22, the size of the first prism sheet 22 can reach a maximum of 500mm to 600mm, so it can be applied to the bonding of larger optical films.

[0045] It should be noted that the optical film directly stacked on the second prism sheet 23 can be a brightness enhancement film 24 or an anti-peep film. In some embodiments, the optical film group 2 can include only the brightness enhancement film 24, or only the anti-peep film, or a layer of optical film with both brightness enhancement and anti-peep functions (that is, a two-in-one composite film formed by integrating the brightness enhancement film 24 and the anti-peep film). In some embodiments, the optical film group 2 includes two layers of optical films, a brightness enhancement film 24 and an anti-peep film. For example, along the direction away from the light guide plate 1, the side of the second prism sheet 23 away from the light guide plate 1 is sequentially stacked with the brightness enhancement film 24 and the anti-peep film. In this embodiment, a fourth adhesive layer is arranged between the brightness enhancement film 24 and the anti-peep film, and the structure of the fourth adhesive layer is the same as that of the first adhesive layer 4, both of which are single-layer adhesive layer structures with planar structures.

[0046] It should be noted that when the length of the bonding and fixing area of ​​each optical film (when each optical film is rectangular, the length of the bonding and fixing area is the length direction or width direction of each optical film) is above 110 mm, the size shrinkage of a commonly used prism in the length direction (MD) is 0.29%, and the size shrinkage in the width direction (TD) is 0.16%; the size shrinkage of DBEF (brightness enhancement film) is measured at a maximum of 0.034%, and the size is relatively stable. Therefore, in this embodiment, the bonding and fixing of the first prism sheet 22 and the second prism sheet 23 are achieved by the second adhesive layer and the third adhesive layer 6. The second adhesive layer 5 and the third adhesive layer 6 are both segmented high and low adhesive layer structures. For the bonding of a single optical film of the first prism sheet 22 or the second prism sheet 23, the bonding length of the first sub-adhesive layer 51 or the bonding length of the second sub-adhesive layer 52 can be set to be less than 110 mm. At this time, the The bonding length of the second adhesive layer is the sum of the bonding length of the first sub-adhesive layer 51 and the bonding length of the second sub-adhesive layer 52. Similarly, the bonding length of the third sub-adhesive layer 61 or the bonding length of the fourth sub-adhesive layer 62 can be set to be less than 110 mm. At this time, the bonding length of the third adhesive layer 6 is the sum of the bonding length of the third sub-adhesive layer 61 and the bonding length of the fourth sub-adhesive layer 62, which not only ensures the overall bonding strength, but also avoids the wrinkle problem caused by the shrinkage of the prism due to the excessive bonding length.

[0047] The dimensional shrinkage of the diffuser 21, the brightness enhancement film 24 and the privacy film is relatively stable. Therefore, the first adhesive layer 4 between the diffuser 21 and the light guide plate 1 is a single-layer adhesive layer structure, and the fourth adhesive layer between the brightness enhancement film 24 and the privacy film adopts a single-layer adhesive layer structure to ensure their bonding strength.

[0048] In summary, the above technical solution is adopted to avoid Figure 1-Figure 4 Problems caused by the bonding method of optical films.

[0049] In an exemplary embodiment, the first sub-adhesive layer 51 and the second sub-adhesive layer 52 are an integral structure.

[0050] In an exemplary embodiment, the third sub-adhesive layer 61 and the fourth sub-adhesive layer 62 are an integral structure.

[0051] In an exemplary embodiment, the orthographic projection of the first sub-adhesive layer 51 on the light guide plate 1 coincides with the orthographic projection of the third sub-adhesive layer 61 on the light guide plate 1;

[0052] The orthographic projection of the second sub-adhesive layer 52 on the light guide plate 1 coincides with the orthographic projection of the fourth sub-adhesive layer 62 on the light guide plate 1 .

[0053] By adopting the above scheme, the first prism sheet 22 and the second prism sheet 23 are bonded and fixed without increasing the bonding length of the first prism sheet 22 or the second prism sheet 23, thereby avoiding the wrinkle problem caused by the shrinkage of the prism sheet due to the excessive bonding length.

[0054] In an exemplary embodiment, in the light emitting direction of the light guide plate 1 , the thickness of the second sub-adhesive layer 52 is greater than the thickness of the first prism sheet 22 ;

[0055] In the light emitting direction of the light guide plate 1 , the thickness of the third sub-adhesive layer 61 is greater than the thickness of the second prism sheet 23 .

[0056] The second sub-adhesive layer 52 needs to pass through the first notch 2001 on the first prism sheet 22 and then be bonded and fixed to the second prism sheet 23. Therefore, in order to ensure the bonding stability between the diffuser 21 and the second prism sheet 23, the thickness of the second sub-adhesive layer 52 is greater than the thickness of the first prism sheet 22.

[0057] Similarly, the third sub-adhesive layer 61 needs to pass through the second notch 2002 on the second prism sheet 23 and then be connected to other optical films (brightness enhancement film 24 or anti-peep film). Therefore, in order to ensure the bonding stability of the second prism sheet 23, the thickness of the third sub-adhesive layer 61 is greater than the thickness of the second prism sheet 23.

[0058] Exemplarily, in the light emitting direction of the light guide plate 1, the second sub-adhesive layer 52 includes a first part and a second part, the thickness of the first part is the same as the thickness of the first prism sheet 22, and the thickness of the second part is 0.05-0.06 mm, but is not limited thereto.

[0059] Exemplarily, in the light emitting direction of the light guide plate 1, the third sub-adhesive layer 61 includes a third part and a fourth part, the thickness of the third part is the same as the thickness of the second prism sheet 23, and the thickness of the fourth part is 0.05-0.06 mm, but is not limited thereto.

[0060] Exemplarily, the thickness of the first adhesive layer 4 is 0.05-0.06 mm, the thickness of the first sub-adhesive layer 51 is 0.05-0.06 mm, and the thickness of the fourth sub-adhesive layer 62 is 0.05-0.06 mm.

[0061] In an exemplary embodiment, the first prism sheet 22 includes a first edge, and in the length direction of the first edge, a portion of the first edge is concave to form the first notch 2001;

[0062] The second prism sheet 23 includes a second edge located on the same side as the first edge, and in the length direction of the second edge, a portion of the second edge is concave to form the second notch 2002, and the orthographic projection of the first notch 2001 on the light guide plate 1 is located on one side of the orthographic projection of the second notch 2002 on the light guide plate 1.

[0063] It should be noted that the bonding and fixing areas of each optical film of the optical film group 2 (i.e., the areas where the corresponding bonding layers are set) are generally in the edge areas of the same side. For example, the optical film group 2 is a rectangular structure as a whole, and the corresponding bonding layers of each optical film are set on the long side or short side of the optical film group 2. The first notch 2001 is to avoid the second sub-adhesive layer 52, and the second notch 2002 is to avoid the third sub-adhesive layer 61. The orthographic projection of the first notch 2001 on the light guide plate 1 is located on one side of the orthographic projection of the second notch 2002 on the light guide plate 1. This is to increase the overall bonding length of the second adhesive layer (the length in the extension direction of the corresponding edge) on the basis of avoiding excessive bonding lengths of the adhesive layer corresponding to the first prism sheet 22 and the adhesive layer corresponding to the second prism sheet 23, so as to ensure the bonding strength of the first prism sheet 22 and the second prism sheet 23.

[0064] Exemplarily, in a direction perpendicular to the extending direction of the first edge, the width of the first notch 2001 is 1.5-3 mm, but is not limited thereto.

[0065] Exemplarily, in a direction perpendicular to the extending direction of the second edge, the width of the second notch 2002 is 1.5-3 mm, but is not limited thereto.

[0066] In an exemplary embodiment, the diffuser 21 includes a third edge, and in the length direction of the third edge, the middle part of the third edge has a first area, the orthographic projection of the first adhesive layer 4 on the diffuser 21 is located in the first area, the orthographic projection of the second adhesive layer on the diffuser 21 is located in the first area, and the orthographic projection of the third adhesive layer 6 on the diffuser 21 is located in the first area.

[0067] In an exemplary embodiment, in the length direction of the third edge, the length of the first region is 4 / 15-6 / 15 of the total length of the third edge.

[0068] In some embodiments, in the length direction of the third edge, the length of the first region is 1 / 3 of the total length of the third edge, thereby ensuring effective bonding strength.

[0069] In an exemplary embodiment, the backlight module also includes a rubber frame arranged around the light guide plate 1, and the optical film group 2 includes a first side 11 and a second side 12 arranged adjacent to each other, and the first side 11 and the second side 12 are both provided with a card slot 201 to cooperate with the corresponding lug 101 on the light guide plate 1.

[0070] Exemplarily, the optical film group 2 is a rectangular structure, including a first side 11 and a third side 13 that are oppositely arranged, and a second side 12 located between the first side 11 and the third side 13. The first side 11, the second side 12 and the third side 13 are provided with the card slot 201, and cooperate with the corresponding lug 101 on the rubber frame to fix the optical film group 2.

[0071] Exemplarily, the second side 12 is a long side of the optical film set 2 , and the first side and the third side are both short sides of the optical film set 2 .

[0072] refer to Figure 5 , exemplarily, the card slot 201 located on the first side 11 is located at one end of the first side 11 close to the second side 12 . The card slot 201 located on the third side 13 is located at one end of the third side 13 close to the second side 12 .

[0073] Exemplarily, the card slot 201 located on the second side 11 is located in the length direction of the second side 12 (refer to Fig.10 The middle part in the X direction in FIG.

[0074] Exemplarily, in the light emitting direction of the light guide plate 1 , the card slot 201 is arranged to penetrate the optical film group 2 .

[0075] Exemplarily, the first adhesive layer 4 , the second adhesive layer 5 and the third adhesive layer 6 are all located on the second side of the optical film assembly 2 .

[0076] The card slot 201 located on the second side 12 is set as the first card slot 201. In the extension direction of the second side 12, the first adhesive layer 4 is divided by the first card slot 201 into two parts located on opposite sides of the first card slot 201. The first sub-adhesive layer 51 and the second sub-adhesive layer 52 are located on opposite sides of the first card slot 201. The third sub-adhesive layer 61 and the fourth sub-adhesive layer 62 are located on opposite sides of the first card slot 201.

[0077] In the extension direction of the second side 12, the first sub-adhesive layer 51 and the second sub-adhesive layer 52 are symmetrically arranged on the opposite sides of the first card slot 201, and the third sub-adhesive layer 61 and the fourth adhesive layer are symmetrically arranged on the opposite sides of the first card slot 201, so that the shrinkage amounts of the first prism sheet 22 at both ends in the extension direction of the second side 12 are consistent, and the shrinkage amounts of the second prism sheet 23 at both ends in the extension direction of the second side 12 are consistent.

[0078] Exemplarily, in a direction perpendicular to the extension direction of the second side 12 (reference Fig.10 In the Y direction of the first side 12, the width of the first adhesive layer 4, the width of the second adhesive layer 5 and the width of the third adhesive layer 6 are set to be the same. In the direction perpendicular to the extension direction of the second side 12, the width of the first adhesive layer 4 is greater than, equal to or less than the width of the first card slot 201.

[0079] In order to ensure the bonding strength, in some embodiments, in a direction perpendicular to the extension direction of the second side 12 , the width of the first bonding layer 4 is greater than the width of the first card slot 201 .

[0080] In an embodiment in which the width of the first adhesive layer 4 is greater than the width of the first card slot 201 in a direction perpendicular to the extension direction of the second side, the first adhesive layer 4 includes a first adhesive portion and a second adhesive portion in a direction perpendicular to the extension direction of the second side 12, and the first adhesive portion is an integral structure, a continuous strip structure, and the first adhesive portion is located on a side of the first card slot 201 away from its open end, and in the extension direction of the second side 12, the second adhesive portion includes a first sub-adhesive portion and a second sub-adhesive portion located on opposite sides of the first card slot 201.

[0081] In the embodiment where the width of the first adhesive layer 4 is greater than the width of the first card slot 201 in the direction perpendicular to the extension direction of the second side 12, the width of the second adhesive layer 5 is greater than the width of the first card slot 201, and in the direction perpendicular to the extension direction of the second side, the second adhesive layer 5 includes a third adhesive portion and a fourth adhesive portion, the third adhesive portion is located on the side of the first card slot 201 away from its open end, the third adhesive portion is an integral structure, a continuous strip structure, and in the extension direction of the second side 12, the fourth adhesive portion includes a third sub-adhesive portion and a fourth sub-adhesive portion located on opposite sides of the first card slot 201. The structure of the third adhesive layer 6 is the same as that of the second adhesive layer.

[0082] In an embodiment in which the width of the first adhesive layer 4 is less than or equal to the width of the first card slot 201 in a direction perpendicular to the extension direction of the second side 12 (in a direction perpendicular to the extension direction of the second side, the width of the first adhesive layer 4, the width of the second adhesive layer and the width of the third adhesive layer 6 are set to be the same), the first adhesive layer 4 is divided into two parts by the first card slot 201;

[0083] In the extension direction of the second side 12 , there is a gap between the first sub-adhesive layer 51 and the first card slot 201 , and there is a gap between the second sub-adhesive layer 52 and the first card slot 201 ;

[0084] In the extension direction of the second side 12 , there is a gap between the third sub-adhesive layer 61 and the first card slot 201 , and there is a gap between the fourth sub-adhesive layer 62 and the first card slot 201 .

[0085] Exemplarily, the thickness of the diffusion sheet 21 is 0.1-0.2 mm, the thickness of the first prism sheet 22 and the second prism sheet 23 are the same, the thickness of the first prism sheet 22 is 0.1-0.3 mm, the thickness of the brightness enhancement film 24 is 0.35-0.4 mm, and the thickness of the anti-peep film is 0.35-0.45 mm.

[0086] An embodiment of the utility model further provides a display device, comprising the above-mentioned backlight module.

[0087] The display device may be any product or component with a display function, such as a liquid crystal television, a liquid crystal display, a digital photo frame, a mobile phone, a tablet computer, etc., wherein the display device further includes a flexible circuit board, a printed circuit board and a backplane.

[0088] There are a few points to note:

[0089] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0090] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0091] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0092] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A backlight module, characterized in that: A light guide plate and an optical film group located on the light exit surface of the light guide plate, wherein the optical film group includes a diffusion sheet, a first prism sheet, a second prism sheet, and a brightness enhancement film and / or an anti-peep film stacked in a direction away from the light guide plate, and the optical film group also includes a first adhesive layer, a second adhesive layer, and a third adhesive layer; The first adhesive layer is disposed between the diffusion sheet and the light guide plate; The second adhesive layer includes a first sub-adhesive layer and a second sub-adhesive layer, the first sub-adhesive layer is bonded between the diffusion sheet and the first prism sheet, the second sub-adhesive layer is bonded between the diffusion sheet and the second prism sheet, and the first prism sheet is provided with a first notch for avoiding the second sub-adhesive layer; The third adhesive layer includes a third sub-adhesive layer and a fourth sub-adhesive layer, the third sub-adhesive layer is bonded between the first prism sheet and the brightness enhancing film or the anti-peep film, the fourth sub-adhesive layer is bonded between the second prism sheet and the brightness enhancing film or the anti-peep film, and a second notch is provided on the second prism sheet for avoiding the third sub-adhesive layer.

2. The backlight module according to claim 1, characterized in that: The first sub-adhesive layer and the second sub-adhesive layer are an integral structure.

3. The backlight module according to claim 1, characterized in that: The third sub-adhesive layer and the fourth sub-adhesive layer are an integral structure.

4. The backlight module according to claim 1, characterized in that: The orthographic projection of the first sub-adhesive layer on the light guide plate coincides with the orthographic projection of the third sub-adhesive layer on the light guide plate; The orthographic projection of the second sub-adhesive layer on the light guide plate coincides with the orthographic projection of the fourth sub-adhesive layer on the light guide plate.

5. The backlight module according to claim 1, characterized in that: In the light emitting direction of the light guide plate, the thickness of the second sub-adhesive layer is greater than the thickness of the first prism sheet; In the light emitting direction of the light guide plate, the thickness of the third sub-adhesive layer is greater than the thickness of the second prism sheet.

6. The backlight module according to claim 1, characterized in that: The first prism sheet comprises a first edge, and in a length direction of the first edge, a portion of the first edge is concave to form the first notch; The second prism sheet includes a second edge located on the same side as the first edge, and in the length direction of the second edge, a portion of the second edge is concave to form the second notch, and the orthographic projection of the first notch on the light guide plate is located on one side of the orthographic projection of the second notch on the light guide plate.

7. The backlight module according to claim 1, characterized in that: The diffuser includes a third edge, and in the length direction of the third edge, the middle part of the third edge has a first area, the orthographic projection of the first adhesive layer on the diffuser is located in the first area, the orthographic projection of the second adhesive layer on the diffuser is located in the first area, and the orthographic projection of the third adhesive layer on the diffuser is located in the first area.

8. The backlight module according to claim 7, characterized in that: In the length direction of the third edge, the length of the first region is 4 / 15-6 / 15 of the total length of the third edge.

9. The backlight module according to claim 1, characterized in that: It also includes a plastic frame surrounding the light guide plate. The optical film group includes a first side and a second side that are adjacent to each other. The first side and the second side are both provided with card slots to match with corresponding lugs on the plastic frame.

10. A display device, characterized in that: The backlight module comprises the backlight module described in any one of claims 1 to 9.

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