TW201323990A - Display device, its backlight module and method of assembling the backlight module - Google Patents

Abstract

A display device, its backlight module and a method of assembling the backlight module are provided in the invention. The backlight module includes a base, a light guide plate disposed on the base and having a corner-chopped portion, and a light source pivotally disposed on the base. A light emitting surface of the light source is contacted flat to a light incident surface of the corner-chopped portion.

Description

Display device, backlight module thereof and assembly method of backlight module

The present invention relates to a backlight module, and more particularly to a backlight module in which a light emitting surface of a light source is attached to a light incident surface of a light guide plate.

The backlight module (Back Light Module) is a key component of a liquid crystal display (LCD). The backlight module supplies a light source with sufficient brightness and uniformity to enable the liquid crystal panel to display images. The backlight module can be roughly classified into a "side light type" and a "straight type" depending on the position of the light source.

For the "side-light" design of the backlight module, the "side-light" design of the backlight module is to set the light source on the light-incident surface of one side of the light guide plate, so that the light source can enter the light guide plate into the light guide plate, and then The light beam travel direction is controlled by the light guide plate to provide a uniform light source for the liquid crystal panel.

When assembling, when the light source is disposed on the light incident surface of the side of the light guide plate, if the light exit surface of the light source and the light incident surface of the light guide plate are not closely close to each other, the light source and the side of the light guide plate may be unexpectedly generated. The gap, as such, will result in a decrease in the light extraction efficiency of the light guide plate.

In this way, how to develop a backlight module can effectively improve the above-mentioned lack and inconvenience, so that the light-emitting surface of the light source and the light-incident surface of the side of the light guide plate can be closely close to each other, thereby maintaining the original light-emitting efficiency of the light guide plate. It is an important issue that the relevant industry is currently unable to delay.

An object of the present invention is to provide a display device, a backlight module thereof, and a method for assembling a backlight module to provide sufficient illumination light for the liquid crystal panel.

Another object of the present invention is to provide a display device, a backlight module thereof, and a method for assembling a backlight module. The concept of forcing the light-emitting surface of the light source to match the light-injecting surface of the light guide plate is matched to avoid attenuating the light-emitting efficiency of the light guide plate. .

One aspect of the present invention discloses a backlight module. The backlight module comprises a base, a light guide plate and a light source. The light guide plate includes a first front surface, a second front surface, two side surfaces and a corner portion. The first front surface is disposed opposite the second front surface, wherein the second front surface is fixed to the base. The two sides are not parallel to each other between the first front side and the second front side. The notched portion includes a light entrance surface. The light incident surface is adjacent between the first front surface and the second front surface and between the side surfaces. The light source is rotatably disposed on the base. The light source includes a light emitting surface. The light emitting surface is in contact with the light incident surface.

In one embodiment of the invention, the base includes a circular slot. The light source further comprises a circular circuit board and a light emitting component. The circular circuit board is rotatably laid flat in a circular slot for rotation within the circular slot. The light-emitting element is disposed on one side of the circular circuit board and protrudes from the circular slot, and the light-emitting surface is located on the light-emitting element for emitting light toward the light-incident surface.

In another embodiment of the invention, the base includes a circular slot. The light source further comprises a circular circuit board, a light-emitting element and a rotating shaft. The light emitting element is disposed on one side of the circular circuit board, and the light emitting surface is located on the light emitting element for emitting light toward the light incident surface. One end of the rotating shaft is connected to one side of the circular circuit board facing away from the light-emitting element, and the other end is inserted into a circular slot for the circular circuit board to rotate relative to the circular slot. In addition, the second front surface includes a recessed portion that abuts the light incident surface for accommodating a portion of the circular circuit board.

In the above two embodiments, the normal direction of one of the faces of the circular circuit board is the same as the axial direction according to the rotation of the circular circuit board.

In still another embodiment of the invention, the base is a U-shaped fixture. The inside of the U-shaped fixing member includes two oppositely disposed and opposite gaps. The light source comprises a circuit board and a light emitting component. The circuit board includes two opposing convex shaft portions. The protruding shaft portions respectively extend into the notches for rotating inside the U-shaped fixing member. The light emitting element is disposed on one side of the circuit board, and the light emitting surface is located on the light emitting element for emitting light toward the light incident surface.

In still another embodiment, one of the normal directions of the face of the circuit board is orthogonal to one of the axial directions according to the rotation of the circuit board.

In the above embodiments, the backlight module further includes an adhesive layer. The adhesive layer is located between the base and the second front surface, and the light guide plate is fixed on the base.

Another aspect of the invention discloses a display device. The display device includes the backlight module and a liquid crystal panel described in the above embodiments. The liquid crystal panel is located on one side of the backlight module.

Another aspect of the present invention discloses a method of assembling a backlight module. The method includes providing a base and a light guide plate, wherein a corner portion of the light guide plate includes a light incident surface; a light source is rotatably disposed on the base; and when the light guide plate is combined with the light source, the light guide plate is used The light incident surface is in contact with one of the light emitting surfaces of the light source, and the light source is rotated relative to the light guide plate until the light incident surface of the light guide plate and the light emitting surface of the light source are adhered to each other; then, the light guide plate is fixed on the base.

In summary, the display device of the present invention, the backlight module thereof and the assembly method of the backlight module can make the light-incident surface of the light guide plate and the light-emitting surface of the light source adhere to each other, and even achieve zero gap, thereby realizing the light guide plate. The light output efficiency, in turn, provides sufficient illumination for the liquid crystal panel.

The present invention will be apparent from the following description and the detailed description of the embodiments of the present invention, which may be modified and modified by the teachings of the present invention without departing from the invention. The spirit and scope.

Since the light-emitting surface of the light source and the light-incident surface of the side of the light guide plate are not closely close to each other, the gap generated between the light source and the light guide plate will cause the light-emitting efficiency of the light beam provided by the light guide plate to decrease.

In view of this, the present invention provides a backlight module. The light source is rotated by the light guide plate, so that one light-emitting surface of the light source is adhered to the light-incident surface along the oblique direction of the light-incident surface of one of the corner portions of the light guide plate, thereby avoiding attenuating the light-emitting efficiency of the light guide plate.

Please refer to FIG. 1 and FIG. 2 , FIG. 1 is an exploded view of a backlight module 100 of the present invention in a first embodiment; and FIG. 2 is a backlight module 100 of the present invention in the first embodiment. Combination diagram.

The invention provides a backlight module 100. The backlight module 100 includes a base 200, a light guide plate 300, and two light sources 400.

The base 200 is, for example, a back plate, a bottom plate or a circuit board for supporting the light source 400 and the light guide plate 300. In this embodiment, the area of the base 200 is greater than or equal to the area of the light guide plate 300, and can completely cover one side of the light guide plate 300, such as a cover body or a U-shaped iron piece. However, the invention is not limited thereto. In addition, in another option of this embodiment, the area of the base is smaller than the area of the light guide plate, and only part of the position of the light guide plate can be covered.

The light guide plate 300 is fixed on the base 200, for example, a plate body 310 having a uniform thickness. The board body 310 includes a first front surface 311, a second front surface 312, two lateral side surfaces 314, two straight side surfaces 315, and two corner portions 316. The first front surface 311 and the second front surface 312 are opposite to each other in parallel. The area of the first front surface 311 or the second front surface 312 is larger than the area of either side. The two lateral sides 314 , the straight side 315 , and the notched portion 316 are adjacent between the first front surface 311 and the second front surface 312 . The two lateral sides 314 are disposed opposite to each other in parallel. The two straight sides 315 are disposed opposite to each other in parallel. Any of the lateral sides 314 are disposed non-parallel to any of the sides 315. The two corner portions 316 are oppositely disposed in the same lateral direction. Both ends of the side 314, and each of the notched portions 316 abuts between the lateral side 314 and the straight side 315 therein.

The name of the notched portion 316 can be seen from a structure in which a corner of one of the rectangular plates is cut away from the first front surface 311 to the second front surface 312, and one of the newly added surfaces is cut into light. The face 317 is not parallel to either of the lateral sides 314 and any of the straight sides 315 and is at an angle to the adjacent lateral sides 314 and the straight sides 315.

The light incident surface 317 of the light guide plate 300 can introduce light into the light guide plate 300. The first front surface 311 of the light guide plate 300 is a light emitting surface for emitting light. The second front surface 312 (Fig. 4) of the light guide plate 300 is a reflecting surface for reflecting light to the light exiting surface.

Each light source 400 is rotatably disposed on the base 200 such that the light source 400 can be rotated freely on the base 200. Therefore, by rotating the light source 400, one of the light-emitting surfaces 422 of each of the light sources 400 can be adhered to the light-incident surface 317 along the oblique direction of the light-incident surface 317 of each of the notch portions 316 of the light guide plate 300, that is, the guide The extending direction of the light incident surface 317 of the light plate 300 and the extending direction of the light emitting surface 422 of the light source 400 are parallel and flat. In this way, when the light-emitting surface 422 of each light source 400 is bonded to the light-incident surface 317 of the light guide plate 300, light leakage caused by the light-emitting surface 422 of the light source 400 and the light-incident surface 317 of the notch portion 316 is not enough to be caused to be light. The light extraction efficiency of the light guide plate 300 is attenuated.

Several embodiments of the light source rotatably disposed on the base are disclosed in the following description to further clarify the details of the different embodiments. However, the examples of the specification are merely illustrative, and the present invention is not limited thereto. Designers can choose the appropriate implementation method based on the above principles.

Please refer to FIG. 3 and FIG. 4 , FIG. 3 is a schematic diagram of a backlight module 100 according to the first embodiment of the present invention; and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2 .

In a variation of the first embodiment, each light source 400 includes a circuit board 410 and at least one light emitting element 420 (such as a light emitting diode element). The light emitting element 420 is disposed on the circuit board 410. In a variation of this embodiment, the circuit board 410 is not limited to a printed circuit board (PCB), a metal core printed circuit board (MCPCB), or a flexible printed circuit board (FPC). .

Specifically, the circuit board of each of the light sources 400 has a disk shape (hereinafter referred to as a circular circuit board 410). The light-emitting element 420 of each light source 400 is a side-view type LED. The base 200 includes two circular slots 210. Each of the circular slots 210 is at least sized to accommodate the circular circuit board 410 described above. The circular circuit board 410 can be placed flat in the circular slot 210 and can be rotated (rotated) in the circular slot 210. The light-emitting element 420 is disposed on one side of the circular circuit board 410 and protrudes from the circular slot 210 (FIG. 4). The light-emitting surface 422 is located on the light-emitting element 420 for emitting light toward the light-incident surface 317. At this time, the circular circuit board 410 is provided with one of the faces of the light-emitting element 420 in the normal direction A1 being the same as the one of the axial directions R1 when the circular circuit board 410 is rotated.

In addition, in this variation, the backlight module 100 further includes an adhesive layer 500 disposed between the base 200 and the second front surface 312 and fixing the light guide plate 300 to the base 200. Further, the adhesive layer 500 is located at a position where the second front surface 312 of the light guide plate 300 is away from the light source 400. However, the present invention does not restrict the adhesive layer from being located at a position where the second front surface of the light guide plate is close to the light source.

Please refer to FIG. 5, which is a schematic diagram of another embodiment of the backlight module 100 of the present invention.

In another variation of the first embodiment, the area of the base 200 is greater than or equal to the area of the light guide plate 300, and one surface of the light guide plate 300 can be completely covered. Therefore, the adhesive layer 500 can be disposed at a position where the second front surface 312 of the light guide plate 300 is away from the light source 400 (as shown) or the second front surface of the light guide plate is close to the light source.

Further, the base 200 is a U-shaped fixing member 220. The fixing member 220 can hold the first front surface 311 and the second front surface 312 of the light guide plate 300, and can fix the position of the light guide plate 300 to ensure that the light emitting surface 422 of the light source 400 closely fits the light incident surface 317 of the light guide plate 300.

Please refer to FIG. 6 and FIG. 7 , FIG. 6 is a schematic diagram of a backlight module 101 according to another embodiment of the present invention; and FIG. 7 is a first embodiment of the backlight module 101 of the present invention. A cross-sectional view of another variation of the example.

In another variation of the first embodiment, the light source 400 further includes a circuit board 410, at least one light emitting element 420 (such as a light emitting diode element), and a rotating shaft 412. The circuit board 410 of each of the light sources 400 has a disk shape (hereinafter referred to as a circular circuit board 410). In a variation of this embodiment, the circuit board is limited to a printed circuit board (PCB), a metal core printed circuit board (MCPCB), or a flexible printed circuit board (FPC).

The light-emitting element 420 is disposed on one surface of the circular circuit board 410, and the light-emitting surface 422 is located on the light-emitting element 420 for emitting light toward the light-incident surface 317. The light-emitting element 420 of each light source 400 is a side-emitting type LED (Side-View Type LED). One end of the rotating shaft 412 is connected to the circular circuit board 410 facing away from one side of the light emitting element 420. The base 200 includes two circular slots 211. Each of the circular slots 211 is at least sized to accommodate the aforementioned shaft 412. Therefore, when the other end of the rotating shaft 412 is inserted into the circular slot 211, the circular circuit board 410 can be laid flat on the base 200 for the rotation (rotation) of the relatively circular slot 211 on the base 200. At this time, the circular circuit board 410 is provided with one of the faces of the side-emitting type LED element, and the normal direction A1 is the same as the one of the axial directions R1 when the circular circuit board 410 is rotated. However, as long as the circuit board 413 of each light source 400 is rotatable, its appearance does not necessarily have a disk shape. In addition, the first front surface 311 includes a recessed portion 313 adjacent to the light incident surface 317 for receiving a portion of the circular circuit board 410.

In addition, in another variation, the backlight module 101 further includes an adhesive layer 500 disposed between the base 200 and the second front surface 312 and fixing the light guide plate 300 to the base 200. Further, the adhesive layer 500 is located at a position where the second front surface 312 of the light guide plate 300 is away from the light source 400. However, the present invention does not restrict the adhesive layer from being located at a position where the second front surface of the light guide plate is close to the light source.

Please refer to FIG. 8 to FIG. 11 , FIG. 8 is an exploded view of the backlight module 102 of the present invention in a second embodiment; and FIG. 9 is a second embodiment of the backlight module 102 of the present invention. Combination diagram. FIG. 10 is a schematic view of the light source 400 and the base 200 viewed in the direction D1 in the second embodiment of the backlight module 102 of the present invention. Figure 11 is a cross-sectional view of the backlight module 102 of the present invention in a second embodiment.

In this second embodiment, the base 200 is a U-shaped fixture 220. The U-shaped fixing member 220 can hold the first front surface 311 and the second front surface 312 of the light guide plate 300, and can fix the position of the light guide plate 300 to ensure that the light-emitting surface 422 of the light source 400 and the light-incident surface 317 of the light guide plate 300 are closely attached. Hehe. The U-shaped fixing member 220 includes a receiving groove 222 and two oppositely disposed and opposite notches 221 . The notch 221 is connected to the receiving groove 222.

Each of the light sources 400 is disposed in the accommodating groove 222, and includes a circuit board 413 and at least one light emitting element 421 (such as a light emitting diode element). The light emitting element 421 is disposed on the circuit board 413 and is a direct light emitting diode. Top-View Type LED. The light emitting surface 422 is located on the light emitting element 421 for emitting light toward the light incident surface 317. The edge of the circuit board 413 includes two opposing convex shaft portions 414. The protruding shaft portions 414 respectively extend into the notches 221 and are rotatable (rotating) inside the U-shaped fixing member 220. At this time, the circular circuit board 410 is provided with a normal direction A2 of one of the faces of the direct-emitting type light-emitting diode element and one of the axial directions R2 according to the rotation of the circuit board 413 is orthogonal to each other.

In a variation of the second embodiment, the circuit board 413 is not limited to a printed circuit board 413 (PCB), a metal core printed circuit board (MCPCB), or a flexible printed circuit board 413 (Flexible Printed Circuit). Board, FPC).

In addition, the backlight module 102 further includes an adhesive layer 500 , and the adhesive layer 500 is located between the base 200 and the second front surface 312 , and the light guide plate 300 is fixed on the base 200 . Further, the adhesive layer 500 is located at a position where the second front surface 312 of the light guide plate 300 is away from the light source 400. However, the present invention does not limit the adhesive layer 500 at a position where the second front surface 312 of the light guide plate 300 is close to the light source 400.

Please refer to FIG. 12, which is a flow chart of a method for assembling a backlight module of the present invention.

The present invention discloses a display device 10. The display device 10 includes the backlight module 100 and a liquid crystal panel 11 described in the above embodiments. The liquid crystal panel 11 is located on one side of the backlight module 100. The display device 10 of the present invention is, for example, a display, a television, a mobile phone, a tablet computer, a notebook computer, a translation machine, a game machine or a road navigation machine, and the like.

Please refer to FIG. 1 , FIG. 8 and FIG. 13 . FIG. 13 is a flow chart of a method for assembling a backlight module according to the present invention.

Another aspect of the present invention discloses a method of assembling a backlight module. This method includes the following steps:

Step (1301): A base 200 and a light guide plate 300 are provided, wherein one of the corner portions 316 of the light guide plate 300 includes a light incident surface 317.

In this step (1301), the detailed description of the base 200 and the light guide plate 300 is as described in the above embodiments.

Step (1302): A light source 400 is rotatably disposed on the base 200.

In this step (1302), a detailed description of the structure in which the light source 400 is rotatably provided on the base 200 is as described in the above embodiments.

Step (1303): Combine the light guide plate 300 with the light source 400 such that the light source 400 rotates relative to the light guide plate 300 until the light incident surface 317 of the light guide plate 300 and the light emitting surface 422 of the light source 400 are in contact with each other.

In this step (1303), when the light guide plate 300 is combined with the light source 400, the light guide plate 300 is translated to approach the light source 400. However, the present invention is not limited to the proximity of the light guide plate 300 to the light source 400, or is approached by the light source 400. The manner of the light guide plate 300.

For example, as shown in FIG. 1 and FIG. 2, when the light guide plate 300 is translated into proximity to the light source 400 (FIG. 1), the light incident surface 317 of the light guide plate 300 contacts the light emitting surface 422 of the light source 400. The light source 400 is pushed to rotate. In order to cater to the oblique direction of the light incident surface 317, the light source 400 is rotated by the light guide plate 300 until the light incident surface 317 of the light guide plate 300 and the light emitting surface 422 of the light source 400 are in contact with each other. In this first embodiment, since the two light sources 400 are limited to the circular slots 211 (Fig. 3 or Fig. 6), when the light incident surface 317 of the light guide plate 300 and the light emitting surface 422 of the light source 400 are mutually After the bonding, the light source 400 cannot continue to be pushed, and one lateral side of the light guide plate 300 is confined between the two light sources 400.

In addition, as shown in FIG. 8 and FIG. 9 , in the second embodiment, when the light guide plate 300 is in translational proximity to the light source 400 ( FIG. 1 ), the light incident surface 317 of the light guide plate 300 contacts the light source 400 . The light emitting surface 422 pushes the light source 400 to rotate. At this time, after the light source 400 is pushed by the light guide plate 300, the convex shaft portion 414 of the circuit board 413 of the light source 400 is first pushed to the bottom of the notch 221 by the light incident surface 317 of the light guide plate 300, and the light source 400 starts to rotate to meet the light source 400. The direction of the light incident surface 317 of the light guide plate 300 is rotated until the light incident surface 317 of the light guide plate 300 and the light emitting surface 422 of the light source 400 are brought into contact with each other. In this second embodiment, since the convex shaft portion 414 of the circuit board 413 of the two light sources 400 is abutted against the bottom of the notch 221 (FIG. 9), when the light incident surface 317 of the light guide plate 300 and the light source 400 are illuminated, After the faces 422 are attached to each other, the light source 400 cannot continue to be pushed, and one lateral side of the light guide plate 300 is confined between the two light sources 400.

Step (1304): Thereafter, the light guide plate 300 is fixed to the base 200.

After the light incident surface 317 of the light guide plate 300 and the light emitting surface 422 of the light source 400 are bonded to each other, the light guide plate 300 can be fixed to the base 200 by the adhesive layer 500 described above. In addition, in addition to the use of the adhesive layer 500, the position of the light guide plate 300 can be fixed by the U-shaped fixing member 220 to ensure that the light-emitting surface 422 of the light source 400 closely adheres to the light-incident surface 317 of the light guide plate 300.

It should be emphasized that the design of the light source rotatably disposed on the base is such that when the light guide plate and the light source are combined, the light incident surface of the light guide plate can be adhered to the light emitting surface of the light source, and is not used for combining the light guide plate and the light source. After that, turn it.

In summary, the display device of the present invention, the backlight module thereof and the assembly method of the backlight module can make the light-incident surface of the light guide plate and the light-emitting surface of the light source adhere to each other, and even achieve zero gap, thereby realizing the light guide plate. The light output efficiency, in turn, provides sufficient illumination for the liquid crystal panel.

The present invention is not limited to the embodiments of the present invention, and various modifications and refinements may be made without departing from the spirit and scope of the present invention. This is subject to the definition of the scope of the patent application.

10. . . Display device

11. . . LCD panel

100, 101, 102. . . Backlight module

200. . . Base

210, 211. . . Circular slot

220. . . U-shaped fastener

221. . . gap

222. . . Locating slot

300. . . Light guide

310. . . Plate body

311. . . First positive

312. . . Second positive

313. . . Depression

314. . . Lateral side

315. . . Straight side

316. . . Notched corner

317. . . Glossy surface

400. . . light source

410. . . Round circuit board

412. . . Rotating shaft

413. . . Circuit board

414. . . Convex shaft

420, 421. . . Light-emitting element

422. . . Luminous surface

500. . . Adhesive layer

A1, A2. . . Normal direction

R1, R2. . . Axis direction

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

1 is an exploded view of a backlight module of the present invention in a first embodiment.

FIG. 2 is a combination view of the backlight module of the present invention in the first embodiment.

FIG. 3 is a schematic view showing a backlight module of the present invention in a variation of the first embodiment.

Figure 4 is a cross-sectional view taken along line 4-4 of Figure 2.

FIG. 5 is a schematic view showing another variation of the backlight module of the present invention in the first embodiment.

FIG. 6 is a schematic view showing a backlight module of the present invention in still another variation of the first embodiment.

Figure 7 is a cross-sectional view showing a backlight module of the present invention in still another variation of the first embodiment.

Figure 8 is an exploded view of the backlight module of the present invention in a second embodiment.

Figure 9 is a combination view of the backlight module of the present invention in the second embodiment.

FIG. 10 is a schematic view of the light source and the base viewed in the direction D1 in the second embodiment of the backlight module of the present invention.

Figure 11 is a cross-sectional view of the backlight module of the present invention in the second embodiment.

Figure 12 is a schematic view of the display device of the present invention.

FIG. 13 is a flow chart of a method for assembling a backlight module of the present invention.

100. . . Backlight module

200. . . Base

300. . . Light guide

310. . . Plate body

311. . . First positive

314. . . Lateral side

315. . . Straight side

316. . . Notched corner

317. . . Glossy surface

400. . . light source

410. . . Round circuit board

420. . . Light-emitting element

422. . . Luminous surface

Claims (12)

A backlight module includes: a base; a light guide plate, comprising: a first front surface and a second front surface oppositely disposed, wherein the second front surface is fixed on the base; the two side surfaces are not parallel to each other Between the first front surface and the second front surface; and a corner portion including a light incident surface adjacent between the first front surface and the second front surface and between the side surfaces; and a light source The rotatably disposed on the base comprises a light emitting surface, and the light emitting surface is in contact with the light incident surface. The backlight module of claim 1, wherein the base comprises a circular slot. The backlight module of claim 2, wherein the light source further comprises: a circular circuit board rotatably disposed in the circular slot for rotating in the circular slot; and a light emitting component And disposed on one side of the circular circuit board and extending the circular slot, the light emitting surface is located on the light emitting element for emitting light toward the light incident surface. The backlight module of claim 2, wherein the light source comprises: a circular circuit board; a light-emitting element disposed on one side of the circular circuit board, the light-emitting surface being located on the light-emitting element for a light-emitting surface; and a rotating shaft, one end of which is connected to the circular circuit board facing away from one side of the light-emitting element, and the other end is inserted into the circular opening for the circular circuit board to rotate relative to the circular groove. The backlight module of claim 4, wherein the second front surface comprises a recessed portion adjacent to the light incident surface for receiving a portion of the circular circuit board. The backlight module of claim 3 or 4, wherein a normal direction of one of the faces of the circular circuit board is the same as an axial direction of the circular circuit board. The backlight module of claim 1, wherein the base is a U-shaped fixing member, and the U-shaped fixing member comprises two oppositely disposed and opposite notches. The backlight module of claim 7, wherein the light source comprises: a circuit board, comprising two opposite protruding shaft portions, wherein the protruding shaft portions respectively extend into the notches for the inside of the U-shaped fixing member Rotating; and a light-emitting element disposed on one side of the circuit board, the light-emitting surface being located on the light-emitting element for emitting light toward the light-incident surface. The backlight module of claim 8, wherein a normal direction of the face of the circuit board is orthogonal to a direction of the axis according to the rotation of the circuit board. The backlight module of claim 1, further comprising: an adhesive layer between the base and the second front surface, and fixing the light guide plate to the base. A display device comprising: a backlight module according to any one of claims 1 to 10; and a liquid crystal panel located on one side of the backlight module. A method for assembling a backlight module includes: providing a base and a light guide plate, wherein a corner portion of the light guide plate includes a light incident surface; a light source is rotatably disposed on the base; and when the light guide plate is When the light source is combined, the light incident surface of the light guide plate is in contact with a light emitting surface of the light source, and the light source is rotated relative to the light guide plate until the light incident surface of the light guide plate and the light emitting surface of the light guide plate are mutually And bonding the light guide plate to the base after the light incident surface of the light guide plate and the light emitting surface of the light source are adhered to each other;