Backlight module and display device

Abstract

The present invention relates to a backlight module and a display device. The backlight module comprises: a frame, a circuit board arranged on the frame, a light guide plate located above the circuit board, at least one light emitting component arranged on the circuit board, and a reflective sheet arranged on the circuit board. A padding portion is formed above the circuit board, and the light emitting component is arranged on the padding portion and aligned with the light incident surface of the light guide plate. The reflective sheet is arranged on the circuit board and at least one end of the reflective sheet is located between the light guide plate and the circuit board. With the aid of the above-mentioned structural design, the light emitting component can be aligned with the light incident surface of the light guide plate, thereby achieving the effect of improving the halo.

Description

Technical Field

[0001] The invention relates to an optical device, in particular to a backlight module and a display device. Background Art

[0002] Display panels and display devices using display panels have become the mainstream of various display devices, such as various panel display screens, household flat-screen TVs, personal computers, mobile phones, and digital camera displays. In particular, the market demand for liquid crystal display devices has grown significantly in recent years. In order to meet the requirements of liquid crystal display devices in terms of function and appearance, the design of backlight modules used in liquid crystal display devices has also become increasingly diversified.

[0003] In order to meet the trend of narrow frame of modern mobile devices or various display devices, the size and configuration of internal components have become the focus of improvement. The stacked optical components are prone to form dark lines caused by the joining of two materials or bright halos caused by different reflectivities under the light guide plate. Therefore, how to take into account the internal space configuration and appearance taste when manufacturing the backlight module is a great challenge for the industry. Summary of the invention

[0004] Therefore, an object of the present invention is to provide a backlight module that meets the trend of narrow frame and has better appearance.

[0005] The backlight module of the present invention comprises a frame, a circuit board arranged on the frame, a light guide plate located above the circuit board, at least one light-emitting component arranged on the circuit board, and a reflective sheet arranged on the circuit board. The circuit board has a first surface, a second surface opposite to the first surface, a first end face connecting the first surface and the second surface, and a second end face opposite to the first end face, and one side of the first surface comprises a raised portion arranged close to the first end face. The light guide plate is located above the first surface of the circuit board and has a light incident surface, and the second end face of the circuit board is located below the light guide plate. At least one light-emitting component is arranged on the raised portion of the circuit board and is aligned with the light incident surface of the light guide plate. The reflective sheet is arranged on the first surface of the circuit board and is located between the light guide plate and the circuit board, and at least one end of the reflective sheet is located between the raised portion and the second end face of the circuit board.

[0006] Another technical means of the present invention is that one side of the second surface of the circuit board includes a recessed portion arranged close to the second end surface, and the backlight module further includes a fixing glue arranged in the recessed portion, and the fixing glue adheres the circuit board to the frame.

[0007] Another technical means of the present invention is that the circuit board includes a substrate layer and a raised layer arranged on one side of the substrate layer, the raised portion is formed by the raised layer, and the step difference between the raised layer and the substrate layer is less than or equal to the thickness of the reflector.

[0008] Another technical means of the present invention is that the reflective sheet extends to the step difference between the padding layer and the substrate layer.

[0009] Another technical means of the present invention is that the circuit board also includes a thickening layer arranged on the other side of the substrate layer, the thickening layer is located below the padding layer, the second surface includes the bottom surface of the thickening layer, the recessed portion is formed by the step difference between the thickening layer and the substrate layer, and the thickness of the thickening layer is substantially the same as the thickness of the fixing glue.

[0010] Another technical means of the present invention is that the area of ​​the elevated layer is not less than the bottom area of ​​at least one light-emitting element.

[0011] Another technical means of the present invention is that the thickened layer covers the range of the raised layer in the thickness direction.

[0012] Another technical means of the present invention is that the recessed portion and the raised portion do not overlap in the thickness direction.

[0013] Another technical means of the present invention is that the backlight module further includes a film unit arranged on the light emitting side of the light guide plate.

[0014] Another object of the present invention is to provide a display device including the aforementioned backlight module.

[0015] The effect of the present invention lies in that, through the above-mentioned structural design, the light-emitting component can be aligned with the light incident surface of the light guide plate, so that the light of the light-emitting component has the best utilization rate, avoiding the efficiency loss of the light-emitting component, and the reflective sheet can be extended to the edge of the light-emitting component, thereby reducing the problem of uneven brightness of the appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of the embodiments and their advantages, the following description is now made with reference to the accompanying drawings, in which:

[0017] Figure 1 is a schematic diagram showing a preferred embodiment of the backlight module of the present invention;

[0018] Figure 2 is a schematic diagram showing the installation method of the circuit board in the preferred embodiment; and

[0019] Figure 3 2 is a schematic diagram showing a preferred embodiment of the display device of the present invention. DETAILED DESCRIPTION

[0020] The features and technical contents of the related patent applications of the present invention will be clearly presented in the detailed description of the preferred embodiments made with reference to the accompanying drawings below. Before the detailed description, it should be noted that similar elements are represented by the same reference numerals.

[0021] See also Figure 1, which is a preferred embodiment of the backlight module of the present invention, comprises a frame 2, a circuit board 3 arranged on the frame 2, a light guide plate 4 located above the circuit board 3, at least one light emitting element 5 arranged on the circuit board 3, a fixing glue 6 for adhering the circuit board 3 to the frame 2, a reflective sheet 7 arranged on the circuit board 3, and a film unit 8 arranged on the light emitting side of the light guide plate 4. Figure 1 From the perspective of FIG. 1 , only one light-emitting element 5 is shown. However, in actual implementation, the number of the light-emitting elements 5 may be multiple, and the multiple light-emitting elements 5 are arranged on the circuit board 3 at intervals.

[0022] The circuit board 3 has a first surface 301, a second surface 302 opposite to the first surface 301, a first end surface 303 connecting the first surface 301 and the second surface 302, and a second end surface 304 opposite to the first end surface 303. One side of the first surface 301 includes a raised portion 305 disposed near the first end surface 303, and one side of the second surface 302 includes a recessed portion 306 disposed near the second end surface 304. For example, in the present embodiment, the circuit board 3 includes a substrate layer 31 for wiring (layout), a raised layer 32 disposed on one side of the substrate layer 31, and a thickening layer 33 disposed on the other side of the substrate layer 31, wherein the first surface 301 is formed by the surface of the raised layer 32 and the surface of the substrate layer 31 not covered by the raised layer 32, and the second surface 302 is formed by the bottom surface of the thickening layer 33 and the surface of the substrate layer 31 not covered by the thickening layer 33. From Figure 1 From the perspective of thickness direction D1, the thickened layer 33 is located below the padding layer 32, the padding portion 305 is formed by the padding layer 32, the padding portion 305 is used to pad the height position of the light emitting element 5 relative to the light guide plate 4, the step difference between the padding layer 32 and the substrate layer 31 is used to accommodate the light guide plate 4, and the recessed portion 306 formed by the step difference between the thickened layer 33 and the substrate layer 31 is used to accommodate the fixing glue 6, and the recessed portion 306 and the padding portion 305 do not overlap in the thickness direction D1, that is, from Figure 1 From the perspective of, the raised portion 305 and the recessed portion 306 are staggered in the left-right direction, that is, in the horizontal direction perpendicular to the thickness direction D1. In addition, it should be noted that the substrate layer 31 in this embodiment can be a flexible printed circuit board (Flexible Printed Circuit, FPC), and the raised layer 32 and the thickening layer 33 can be formed by a protective film (coverlay), such as: polyethylene terephthalate (PET) cover film, polyimide (PI) cover film or photoimageable coverlay (PIC), but not limited to this; in some embodiments, the substrate layer 31, the raised layer 32 and the thickening layer 33 can also be an integrally formed structure.

[0023] Next, see Figure 2 The fixing method of the circuit board 3 on the frame 2 is described below. Since the fixing glue 6 is only provided in the recessed portion 306, rather than being adhered to the entire lower surface of the substrate layer 31, during assembly, the circuit board 3 and the frame 2 can be formed as shown in FIG. Figure 2 (a) is used for alignment at an angle θ. At this time, the fixing glue 6 does not contact the frame 2, so the circuit board 3 can still move. After confirming the pasting position, put down the circuit board 3 so that the fixing glue 6 can paste the circuit board 3 on the frame 2 to form a Figure 2 (b) The structure shown in FIG. 3. Since the thickness of the thickening layer 33 is substantially the same as the thickness of the fixing glue 6, the substrate layer 31 can be stably supported without tilting.

[0024] In more detail, the light emitting element 5 is disposed on the elevating layer 32, and the area of ​​the elevating layer 32 is preferably not less than the bottom area of ​​the light emitting element 5, so the elevating layer 32 can completely support the light emitting element 5. In addition, the thickening layer 33 is located below the elevating layer 32, and in the thickness direction D1, the thickening layer 33 covers the range of the elevating layer 32, so the thickening layer 33 can completely support the elevating layer 32. Therefore, the above structural design can ensure that the light emitting element 5 is firmly supported and kept horizontal without tilting, so as to maintain the best light output angle.

[0025] See also Figure 1 After the positioning of the circuit board 3 is completed, the reflective sheet 7, the light guide plate 4 and the film unit 8 are installed, so that the reflective sheet 7 is sandwiched between the light guide plate 4 and the circuit board 3, and extends to the step difference between the padding layer 32 and the substrate layer 31. The circuit board and the reflective sheet in the conventional backlight module are located on the same horizontal plane, and the area of ​​the circuit board will be limited by the setting position of the reflective sheet. Therefore, there is a limit to the wiring area of ​​the conventional circuit board. However, in contrast to the present embodiment, the wiring of the circuit board 3 is arranged in the substrate layer 31, and the substrate layer 31 is located below the reflective sheet 7. Therefore, the substrate layer 31 is not limited by space, and the area of ​​the substrate layer 31 can be increased or decreased according to the wiring requirements. It should be particularly noted that the step difference between the padding layer 32 and the substrate layer 31 (that is, the thickness of the padding layer 32) is less than or equal to the thickness of the reflective sheet 7. By adjusting the thickness of the padding layer 32 and the reflective sheet 7, the light-emitting element 5 can be aligned with the light incident surface 41 of the light guide plate 4 without deviation, so as to maintain the best light coupling effect.

[0026] See also Figure 3 A display device can be formed by arranging a display panel 9 on the light emitting surface of the backlight module of the present invention.

[0027] With the aid of the above structural design, the backlight module and the display device of the present invention have the following effects:

[0028] 1. Improving the poor appearance: The present invention utilizes the raising layer 32 to raise the light-emitting component 5, so that the light-emitting component 5 can be aligned with the light incident surface 41 of the light guide plate 4, so that the light of the light-emitting component 5 has the best optical coupling effect, and at the same time, the reflective sheet 7 can be sandwiched between the light guide plate 4 and the substrate layer 31 of the circuit board 3, and one end of the reflective sheet 7 can be extended as far as possible to the edge of the light-emitting component 5, and the light guide plate 4 can have only one kind of reflective material below, thereby achieving the effect of improving the uniformity of light output, and improving the dark line caused by the bonding of two materials or the bright halo caused by different reflectivities below the conventional light guide plate.

[0029] 2. Improved assembly convenience: Since the fixing glue 6 is disposed in the recessed portion 306 instead of being adhered to the entire lower surface of the substrate layer 31 , the circuit board 3 can be aligned and assembled in an inclined manner, thereby improving the convenience of alignment, assembly, and rework.

[0030] 3. Increase the wiring area: Since the reflector 7 is partially overlapped on the substrate layer 31 of the circuit board 3 and the reflector 7 and the substrate layer 31 are not in the same horizontal plane, the reflector 7 and the substrate layer 31 will not interfere with each other, so that the size of the substrate layer 31 can be increased to increase the wiring area of ​​the substrate layer 31.

[0031] In summary, the backlight module and display device of the present invention, by means of the above-mentioned internal configuration, can align the light-emitting component 5 with the light-incident surface 41 of the light guide plate 4, so that the light has the best utilization rate, avoiding the efficiency loss of the light-emitting component 5, and can extend the reflective sheet 7 to the edge of the light-emitting component 5, reducing the problem of uneven brightness of the appearance. In addition, the setting position of the fixing glue 6 can improve the convenience of alignment, assembly, and rework of the circuit board 3. Furthermore, the reflective sheet 7 does not interfere with the substrate layer 31 of the circuit board 3, so it can increase the wiring area, and truly achieve the purpose of the present invention.

[0032] The above is only a preferred embodiment of the present invention, and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made according to the scope of the claims and the content of the specification of the present invention are still within the scope of the patent of the present invention.

[0033] [List of Reference Numerals]

[0034] 2 Framework

[0035] 3 Circuit Board

[0036] 301 First Surface

[0037] 302 Second Surface

[0038] 303 First end face

[0039] 304 Second end face

[0040] 305 Raised Section

[0041] 306 Depression

[0042] 31 substrate layer

[0043] 32 Raised layer

[0044] 33 Thickening layer

[0045] 4 Light guide plate

[0046] 41 Light incident surface

[0047] 5. Luminous parts

[0048] 6. Fixing glue

[0049] 7 Reflective sheet

[0050] 8 Diaphragm unit

[0051] 9 Display Panel

[0052] θ Bevel angle

[0053] D1 thickness direction.

Claims

1. A backlight module, characterized in that: Include: frame; A circuit board, which is disposed on the frame and has a first surface, a second surface opposite to the first surface, a first end surface connecting the first surface and the second surface, and a second end surface opposite to the first end surface, and one side of the first surface includes a raised portion disposed close to the first end surface; a light guide plate, which is located above the first surface of the circuit board and has a light incident surface, and the second end surface of the circuit board is located below the light guide plate; At least one light-emitting element is disposed on the elevated portion of the circuit board, and the at least one light-emitting element is aligned with the light incident surface of the light guide plate; and a reflective sheet disposed on the first surface of the circuit board and located between the light guide plate and the circuit board, wherein at least one end of the reflective sheet is located between the raised portion and the second end surface of the circuit board, Among them, one side of the second surface of the circuit board includes a recessed portion arranged close to the second end surface, and the backlight module further includes a fixing glue arranged in the recessed portion, and the fixing glue adheres the circuit board to the frame.

2. The backlight module according to claim 1, characterized in that: The circuit board includes a substrate layer and a raised layer arranged on one side of the substrate layer, the raised portion is formed by the raised layer, and a step difference between the raised layer and the substrate layer is less than or equal to a thickness of the reflector.

3. The backlight module according to claim 2, characterized in that: The reflective sheet extends to the step difference between the padding layer and the substrate layer.

4. The backlight module according to claim 2, characterized in that: The circuit board also includes a thickening layer arranged on the other side of the substrate layer, the thickening layer is located below the padding layer, the recessed portion is formed by the step difference between the thickening layer and the substrate layer, and the thickness of the thickening layer is substantially the same as the thickness of the fixing glue.

5. The backlight module according to claim 4, characterized in that: The area of ​​the raised layer is not less than the bottom area of ​​the at least one light emitting element.

6. The backlight module according to claim 5, characterized in that: In the thickness direction, the thickened layer covers the range of the raised layer.

7. The backlight module according to any one of claims 1 to 6, characterized in that: The recessed portion and the raised portion do not overlap in a thickness direction.

8. The backlight module according to claim 1, characterized in that: It also includes a film unit arranged on the light emitting side of the light guide plate.

9. A display device, characterized in that: The invention comprises a backlight module according to any one of claims 1 to 8 and a display panel arranged on a light emitting surface of the backlight module.

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