Backlight module and its positioning and resilient structure

Abstract

The present invention discloses a backlight module, which includes a back plate, a light guide plate, an optical film group and a positioning and resilient structure. The light guide plate is disposed on the back plate, and a first space and a second space are respectively reserved between opposite two wall portions of the back plate and opposite two side surfaces of the light guide plate. The optical film group is disposed on the light guide plate and extends into the first space, and a limiting groove is formed on the extending end. The positioning and resilient structure includes a first elastic piece and a second elastic piece. The first elastic piece includes a first deformation portion, a first chamfer portion and a first positioning portion which are sequentially connected. The second elastic piece includes a second deformation portion, a second chamfer portion and a second positioning portion which are sequentially connected. The first elastic piece and the second elastic piece are respectively disposed in the first space and the second space. The first deformation portion faces one side surface of the light guide plate and is inserted into the limiting groove, and the second deformation portion faces the other side surface of the light guide plate. This backlight module has better optical stability.

Description

Technical Field

[0001] The present invention relates to a backlight module and a positioning and rebounding structure thereof. Background Art

[0002] At present, there are more and more requirements for high temperature and high brightness of liquid crystal displays, and there is a greater demand for the expansion and contraction space of light guide plates and optical films (for example: dual brightness enhancement film (DBEF)). In the design of backlight modules, sufficient expansion and contraction space needs to be reserved to meet the thermal expansion requirements of light guide plates and / or reflective brightness enhancement films. However, the retention of the expansion and contraction space easily leads to poor optical stability of the light guide plate and / or reflective brightness enhancement film, resulting in poor display quality and affecting image display. Summary of the Invention

[0003] The present invention provides a backlight module and a positioning and rebounding structure thereof. The positioning and rebounding structure has the advantages of simple structure and convenient assembly, and provides the backlight module with better optical stability.

[0004] The backlight module provided by the present invention includes a back plate, a light guide plate, an optical film group, and a positioning and rebounding structure. The back plate has a bottom and two opposite wall portions connected to the bottom; the light guide plate has opposite side surfaces, the light guide plate is disposed on the bottom, and a first space and a second space are respectively reserved between the two wall portions and the side surfaces; the optical film group is disposed on the light guide plate, and the optical film group has an extending end extending onto the first space, and a limiting groove is formed on the extending end; the positioning and rebounding structure includes a first elastic sheet and a second elastic sheet. The first elastic sheet is disposed on the bottom and located in the first space. The first elastic sheet includes a first deformation portion, a first chamfer portion, and a first positioning portion connected in sequence. The first positioning portion is disposed on the bottom, the first deformation portion faces one of the side surfaces of the light guide plate, and the first deformation portion is inserted into the limiting groove. The second elastic sheet is disposed on the bottom and located in the second space. The second elastic sheet includes a second deformation portion, a second chamfer portion, and a second positioning portion connected in sequence. The second positioning portion is disposed on the bottom, and the second deformation portion faces the other side surface of the light guide plate.

[0005] In an embodiment of the present invention, the above-mentioned light guide plate has a thickness, the first chamfer portion and the second chamfer portion are arc chamfers, and the radius of the arc chamfer is between one-third and two-thirds of the thickness.

[0006] In an embodiment of the present invention, the length of the first deformation portion is greater than the length of the second deformation portion. Among them, one end of the first deformation portion away from the first chamfer portion passes through the limiting groove and protrudes from the optical film group, and one end of the second deformation portion away from the second chamfer portion does not protrude from the side of the light guide plate adjacent to the optical film group.

[0007] In an embodiment of the present invention, the above-mentioned first positioning portion and second positioning portion are respectively attached to the bottom of the back plate by screws.

[0008] In an embodiment of the present invention, the above-mentioned first positioning portion and second positioning portion are respectively fixed to the bottom of the back plate by an adhesive layer.

[0009] In an embodiment of the present invention, the above-mentioned backlight module further includes a front frame, and the front frame is adapted to be fixed to the back plate to form a receiving space, and the light guide plate, the optical film group, the first elastic piece and the second elastic piece are located in the receiving space.

[0010] The positioning and resilient structure provided by the present invention includes a first elastic piece and a second elastic piece. The first elastic piece includes a first deformation portion, a first chamfer portion and a first positioning portion connected in sequence; the second elastic piece includes a second deformation portion, a second chamfer portion and a second positioning portion connected in sequence, wherein the second deformation portion faces the first deformation portion, and the length of the first deformation portion is greater than the length of the second deformation portion.

[0011] By setting the positioning and resilient structure in the backlight module of the present invention, at normal temperature, the first elastic piece can be used to limit the light guide plate and the optical film group, so that the optical characteristics are not affected by assembly and the optical stability can be guaranteed. At high temperature, the deformation of the first elastic piece and the second elastic piece is used to increase the expansion and contraction space to avoid deformation of the light guide plate; in addition, the design that the second deformation portion of the second elastic piece does not extend to the optical film group provides an expansion and contraction space for the optical film group, avoiding the situation that the optical film group expands and contracts insufficiently at high temperature.

[0012] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional view of the structure of a backlight module according to an embodiment of the present invention.

[0014] Figure 2A and 2B are respectively schematic structural views of the first elastic piece and the second elastic piece according to an embodiment of the present invention.

[0015] Figure 3 is a partial cross-sectional view of the first elastic piece or the second elastic piece of the positioning and resilient structure provided on the back plate according to another embodiment of the present invention.

[0016] Figure 4 is a schematic view of the deformation of the first elastic piece or the second elastic piece of the positioning and resilient structure according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Figure 1 is a schematic cross-sectional view of the structure of a backlight module according to an embodiment of the present invention. As Figure 1 shown, the backlight module 10 includes a back plate 12, a light guide plate 14, an optical film stack 16, and a positioning and resilient structure 18. The back plate 12 has a bottom 121 and two opposite side walls 122, 122'. The light guide plate 14 has a light incident surface (not labeled) and two opposite side surfaces 141, 141'. The light incident surface is, for example, parallel to the cross-section 142 and faces a light source assembly (not shown in the figure). The light incident surface connects the two side surfaces 141, 141'. The light guide plate 14 is disposed on the bottom 121 of the back plate 12, and a first space 20 and a second space 22 are respectively reserved between the two side walls 122, 122' of the back plate 12 and the two side surfaces 141, 141' of the light guide plate 14. Further, the light guide plate 14 has a thickness T. The optical film stack 16 is disposed on the light guide plate 14, and the optical film stack 16 has an extending end 16a extending onto the first space 20, and a limiting groove 24 is formed on the extending end 16a. In one embodiment, the optical film stack 16 may include a diffuser sheet, a prism sheet, and a dual brightness enhancement film (DBEF), and other optical films may also be used. Those with ordinary knowledge in the art can consider different combinations and quantity collocations according to requirements.

[0018] Continuing the above description, the positioning and resilient structure 18 includes a first elastic piece 26 and a second elastic piece 28. The first elastic piece 26 is disposed on the bottom 121 of the back plate 12 and is located in the first space 20. The second elastic piece 28 is disposed on the bottom 121 of the back plate 12 and is located in the second space 22. Figure 2A and 2B are respectively schematic structural views of the first elastic piece and the second elastic piece according to an embodiment of the present invention. As Figure 2A shown, the first elastic piece 26 includes a first deformation portion 261, a first chamfer portion 262, and a first positioning portion 263 connected in sequence. As Figure 2B shown, the second elastic piece 28 includes a second deformation portion 281, a second chamfer portion 282, and a second positioning portion 283 connected in sequence. As Figure 1 shown, the first positioning portion 263 of the first elastic piece 26 is disposed on the bottom 121, the first deformation portion 261 faces one of the side surfaces 141 of the light guide plate 14, and the first deformation portion 261 is inserted into the limiting groove 24 of the optical film stack 16. The second positioning portion 283 of the second elastic piece 28 is disposed on the bottom 121, and the second deformation portion 281 faces the other side surface 141' of the light guide plate 14. The length L2 of the second deformation portion 281 of the second elastic piece 28 is less than the length L1 of the first deformation portion 261 of the first elastic piece 26.

[0019] The first chamfered portion 262 of the first elastic piece 26 and the second chamfered portion 282 of the second elastic piece 28 are, for example, arc chamfers, and the radius R of the arc chamfer is between one-third and two-thirds of the thickness T of the light guide plate 14, that is, (1 / 3)T ≤ R ≤ (2 / 3)T, so as to enhance the resilience of the first elastic piece 26 and the second elastic piece 28, and at the same time avoid deformation of the first elastic piece 26 and the second elastic piece 28 due to stress concentration. In one embodiment, the materials of the first elastic piece 26 and the second elastic piece 28 are, for example, stainless steel.

[0020] In one embodiment, the number of the first elastic pieces 26 located in the first space 20 and the number of the second elastic pieces 28 located in the second space 22 may be the same or different, and the first elastic pieces 26 and the second elastic pieces 28 may be opposite to each other or staggeredly arranged. In one embodiment, a single first elastic piece 26 and a single second elastic piece 28 may be respectively arranged in the first space 20 and the second space 22 and respectively correspond to the middle region of the light guide plate 14; alternatively, the number of the first elastic pieces 26 and the second elastic pieces 28 may be multiple, and they are evenly distributed in the first space 20 and the second space 22 respectively.

[0021] Continuing the above description, the number of the limiting grooves 24 provided on the extending end 16a of the optical film group 16 corresponds to the number of the first elastic pieces 26. The limiting grooves 24 are, for example, rectangular grooves, and the shape of the limiting grooves 24 can generally correspond to the contour of the first deformed portion 261, so that one end of the first deformed portion 261 away from the first chamfered portion 262 passes through the limiting groove 24 and protrudes from the optical film group 16, so as to synchronously limit the light guide plate 14 and the optical film group 16; wherein the opening area of the limiting groove 24 can be slightly larger than the cross-sectional area of the first deformed portion 261, so that the first deformed portion 261 passing through the limiting groove 24 still has a space for slight deformation. Also, one end of the second deformed portion 281 away from the second chamfered portion 282 does not protrude from the side of the light guide plate 14 adjacent to the optical film group 16, so as to avoid the problem that the second deformed portion 281 affects the insufficient thermal expansion and contraction of the optical film group 16 due to high temperature expansion.

[0022] Please continue to refer to Figure 1 As shown, the backlight module 10 further includes, for example, a front frame 30. The front frame 30 is adapted to be fixed to the back plate 12 to form an accommodation space 32. The light guide plate 14, the optical film group 16, the first elastic piece 26 and the second elastic piece 28 are located in the accommodation space 32. In one embodiment, as Figure 1 shown, a receiving groove 301 may be further formed on the inner side of the bottom 121 of the front frame 30 facing the back plate 12 to receive a part of the first deformed portion 261 protruding from the optical film group 16.

[0023] Please continue to refer to Figure 1As shown, the first positioning portion 263 of the first elastic piece 26 and the second positioning portion 283 of the second elastic piece 28 are attached to the bottom 121 of the back plate 12 by screws 34, but it is not limited thereto. Figure 3 It is a partial cross-sectional view of the first elastic piece or the second elastic piece of the positioning and rebounding structure according to another embodiment of the present invention disposed on the back plate. Figure 3 It is illustrated by fixing the first elastic piece 26, as Figure 3 As shown, the first positioning portion 263 of the first elastic piece 26 is fixed to the bottom 121 of the back plate 12 by an adhesive layer 36. Correspondingly, please refer to the following Figure 4 As shown, the second elastic piece 28 can also be fixed to the bottom 121 of the back plate 12 by an adhesive bonding method, but the setting method of the first elastic piece 26 or the second elastic piece 28 is not limited thereto.

[0024] In an embodiment, when assembling the backlight module 10, for example, the first elastic piece 26 and the second elastic piece 28 can be respectively fixed to the first space 20 and the second space 22 reserved on the back plate 12 first, and then the light guide plate 14 is directly placed on the bottom 121 of the back plate 12 between the first elastic piece 26 and the second elastic piece 28. At this time, the first deformation portion 261 of the first elastic piece 26 and the second deformation portion 281 of the second elastic piece 28 can appropriately contact the side surfaces 141, 141' of the light guide plate 14 and no deformation occurs; or there is a slight gap between the first deformation portion 261 / the second deformation portion 281 and the side surfaces 141 / 141' of the light guide plate 14. Then, the optical film stack 16 is disposed on the light guide plate 14, and one end of the first deformation portion 261 of the first elastic piece 26 is adapted to protrude from the limiting groove 24 of the optical film stack 16; finally, the front frame 30 and the back plate 12 are fixed together. In the backlight module 10 of the embodiment of the present invention, the first elastic piece 26 and the second elastic piece 28 can be installed on the bottom 121 of the back plate 12 without forming a through hole in the bottom 121 of the back plate 12, so that the design for dust prevention and light leakage prevention does not need to be increased due to the formation of a through hole, thereby avoiding the increase in cost.

[0025] Figure 4 It is a deformation diagram of the first elastic piece or the second elastic piece of the positioning and rebounding structure according to an embodiment of the present invention, in which the expansion of the light guide plate 14 and the deformation of the second elastic piece 28 are illustrated, as Figure 4As shown, when the light guide plate 14 expands due to heat, the second deformation portion 281 of the second elastic piece 28 will be turned outwards by the acting force N of the expansion of the light guide plate 14. That is, the turning-outwards direction of the second deformation portion 281 is the same as the expansion direction. By the second deformation portion 281 of the second elastic piece 28 being obliquely inclined outwards, the accommodating space 32 is increased, and at the same time, the expansion and contraction space of the light guide plate 14 is provided to accommodate the volume of the light guide plate 14 when it expands due to heat, which can avoid the problem of poor taste caused by the deformation of the light guide plate 14. Also, once the acting force N of expansion is released, the second elastic piece 28 can return to its initial state by the resilience of the second chamfer portion 282. Correspondingly, in an embodiment not shown, the first deformation portion of the first elastic piece is also turned outwards by the acting force of the expansion of the light guide plate, and once the acting force of expansion is released, the first elastic piece can return to its initial state.

[0026] According to the above, in the backlight module of the embodiment of the present invention, by the setting of the positioning and resilient structure, at normal temperature, the first elastic piece can be used to limit the light guide plate and the optical film sheet group, so that the optical characteristics are not affected by the assembly and the optical stability can be guaranteed. At high temperature, the deformation of the first elastic piece and the second elastic piece is used to increase the expansion and contraction space to avoid the deformation of the light guide plate. Also, the design that the second deformation portion of the second elastic piece does not extend to the optical film sheet group provides the expansion and contraction space for the optical film sheet group to avoid the situation that the optical film sheet group has insufficient expansion and contraction at high temperature. The positioning and resilient structure of the embodiment of the present invention is used for the expansion and contraction buffering of the light guide plate and the limitation of the optical film sheet group, with a simple structure and convenient assembly, making the backlight module have the advantages of good optical stability and good optical taste.

[0027] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make some changes or modifications by using the above-disclosed methods and technical contents into equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A backlight module, characterized in that, Comprising: A backplate having a bottom and two opposite side walls connected to the bottom; A light guide plate having opposite side faces, the light guide plate being disposed on the bottom, and a first space and a second space being respectively reserved between the two side walls and the two side faces; An optical film group disposed on the light guide plate, and the optical film group having an extended end extending onto the first space, and at least one limiting groove being formed on the extended end; And A positioning and resilient structure including at least one first elastic piece and at least one second elastic piece, wherein: The at least one first elastic piece is disposed on the bottom and located in the first space, the at least one first elastic piece includes a first deformation portion, a first chamfered portion and a first positioning portion connected in sequence, wherein the first positioning portion is disposed on the bottom, the first deformation portion faces one of the two side faces, and the first deformation portion is inserted into the at least one limiting groove; and The at least one second elastic piece is disposed on the bottom and located in the second space, the at least one second elastic piece includes a second deformation portion, a second chamfered portion and a second positioning portion connected in sequence, the second positioning portion is disposed on the bottom, and the second deformation portion faces the other of the two side faces, wherein the length of the first deformation portion is greater than the length of the second deformation portion, one end of the first deformation portion away from the first chamfered portion passes through the at least one limiting groove and protrudes from the optical film group, and one end of the second deformation portion away from the second chamfered portion does not protrude from the side of the light guide plate adjacent to the optical film group.

2. The backlight module according to claim 1, wherein, The light guide plate has a thickness, the first chamfered portion and the second chamfered portion are arc chamfers, and the radius of the arc chamfer is between one-third and two-thirds of the thickness.

3. The backlight module according to claim 1, characterized in that, The first positioning portion and the second positioning portion are respectively fastened to the bottom of the backplate by a screw.

4. The backlight module according to claim 1, wherein, The first positioning portion and the second positioning portion are respectively fixed to the bottom of the backplate by an adhesive layer.

5. The backlight module according to claim 1, wherein The backlight module further includes a front frame, the front frame being adapted to be fixed to the backplate to form an accommodation space, and the light guide plate, the optical film group, the at least one first elastic piece and the at least one second elastic piece are located in the accommodation space.

6. A positioning and spring-back structure, characterized in that, Suitable for application in a backlight module, the backlight module includes a light guide plate and an optical film group, the light guide plate has opposite side faces, the optical film group is disposed on the light guide plate, the optical film group has at least one limiting groove, and the positioning and resilient structure includes: At least one first elastic piece including a first deformation portion, a first chamfered portion and a first positioning portion connected in sequence, the first deformation portion faces one of the two side faces, and the first deformation portion is inserted into the at least one limiting groove; and At least one second elastic piece, including a second deformation part, a second chamfer part and a second positioning part connected in sequence, wherein the second deformation part faces the other one of the two side surfaces, the length of the first deformation part is greater than the length of the second deformation part, and one end of the second deformation part far from the second chamfer part does not protrude from the side of the light guide plate adjacent to the optical film group.

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