CN115016166A - Backlight module and display device - Google Patents

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 element arranged on the circuit board and a reflective sheet arranged on the circuit board. A raised portion is formed above the circuit board, and the light-emitting element is disposed on the raised portion and aligned with the light incident surface of the light guide plate. The reflection sheet is arranged on the circuit board and at least one end is located between the light guide plate and the circuit board. With the aid of the above structural design, the light-emitting element can be aligned with the light incident surface of the light guide plate, thereby achieving the effect of improving the halo.

Description

Backlight module and display device

technical field

The present invention relates to an optical device, in particular to a backlight module and a display device.

Background technique

Display panels and display devices using display panels have become the mainstream of various types of display devices, such as various panel display screens, flat-screen TVs for home use, display screens for personal computers, mobile phones, and digital cameras. Especially in recent years, the market demand for liquid crystal display devices has grown significantly. In order to meet the functional and appearance requirements of liquid crystal display devices, the designs of backlight modules used in liquid crystal display devices are also increasingly diversified.

In order to cope with the trend of narrow borders of modern mobile devices or various display devices, the size and configuration of internal components have become the focus of improvement, and the layered optical components are prone to form dark lines under the light guide plate due to the bonding of the two materials. Or the problem of bright halo caused by different reflectivity. 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

Therefore, an object of the present invention is to provide a backlight module that conforms to the trend of narrow bezels and has a better appearance.

The backlight module of the present invention includes a frame, a circuit board arranged on the frame, a light guide plate located above the circuit board, at least one light-emitting element arranged on the circuit board, and a reflection sheet arranged on the circuit board. The circuit board 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 surface close to the first surface. A raised portion provided on one 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 surface of the circuit board is located below the light guide plate. At least one light-emitting element 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 of the circuit board and the second end surface.

Another technical means of the present invention is that one side of the second surface of the circuit board includes a concave portion disposed near the second end face, and the backlight module further includes a fixing glue disposed in the depressed portion, and the fixing glue adheres the circuit board to the frame .

Another technical means of the present invention is that the circuit board includes a substrate layer and a pad layer disposed on one side of the substrate layer, the pad portion is formed by the pad layer, and the step difference between the pad layer and the substrate layer is less than or equal to the thickness of the reflective sheet.

Another technical means of the present invention is that the reflective sheet extends to the level difference between the pad layer and the substrate layer.

Another technical means of the present invention is that the circuit board further includes a thickening layer disposed on the other side of the substrate layer, the thickening layer is located below the pad layer, the second surface includes the bottom surface of the thickening layer, and the concave portion is formed by the thickening layer. The level difference between the layer and the substrate layer is formed, and the thickness of the thickened layer is substantially the same as the thickness of the fixing glue.

Another technical means of the present invention is that the area of the backing layer is not less than the area of the bottom surface of the at least one light-emitting element.

Another technical means of the present invention is that in the thickness direction, the thickened layer covers the range of the underlayer.

Another technical means of the present invention resides in that the recessed portion and the raised portion do not overlap in the thickness direction.

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

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

The effect of the present invention is that, through the above structural design, the light-emitting element can be aligned with the light incident surface of the light guide plate, so that the light of the light-emitting element has the best utilization rate, the efficiency loss of the light-emitting element can be avoided, and the reflective sheet can be extended to emit light. the edges of the pieces, thereby reducing the problem of uneven appearance.

Description of drawings

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

1 is a schematic diagram illustrating a preferred embodiment of a backlight module of the present invention;

FIG. 2 is a schematic diagram showing the mounting manner of the circuit board in the preferred embodiment; and

FIG. 3 is a schematic diagram illustrating a preferred embodiment of the display device of the present invention.

Detailed ways

The features and technical contents of the related applications of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the accompanying drawings. Before proceeding to the detailed description, it should be noted that similar elements are denoted by the same reference numerals.

Referring to FIG. 1 , it is a preferred embodiment of the backlight module of the present invention, which includes a frame 2 , a circuit board 3 disposed on the frame 2 , a light guide plate 4 located above the circuit board 3 , and at least a light guide plate 4 disposed on the circuit board 3 A light-emitting element 5 , a fixing glue 6 for adhering the circuit board 3 to the frame 2 , a reflective sheet 7 disposed on the circuit board 3 , and a diaphragm unit 8 disposed on the light-emitting side of the light guide plate 4 . From the perspective of FIG. 1 , only one light-emitting element 5 is shown, but in actual implementation, the number of light-emitting elements 5 may be multiple, and the plurality of light-emitting elements 5 are arranged on the circuit board 3 at intervals.

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 close to the first end surface 303 , and one side of the second surface 302 includes a concave portion 306 disposed close to the second end surface 304 . For example, in this embodiment, the circuit board 3 includes a substrate layer 31 for wiring, a pad layer 32 disposed on one side of the substrate layer 31 , and a thickening layer disposed on the other side of the substrate layer 31 33, wherein the first surface 301 is formed by the surface of the pad layer 32 and the surface of the substrate layer 31 not covered by the pad layer 32, and the second surface 302 is formed by the bottom surface of the thickened layer 33 and the substrate layer 31 not covered by the thickened layer 33 The covered surfaces are collectively formed. From the perspective of FIG. 1 , along the thickness direction D1 , the thickened layer 33 is located below the pad layer 32 , and the pad 305 is formed by the pad layer 32 , and the pad 305 is used to elevate the light-emitting element 5 relative to the light guide plate 4 The height position of the upper layer 32 and the substrate layer 31 is used for accommodating the light guide plate 4, and the recess 306 formed by the difference between the thickening layer 33 and the substrate layer 31 is used for accommodating the fixing glue 6, and the recess is 306 and the raised portion 305 do not overlap in the thickness direction D1, that is to say, from the perspective of FIG. stagger. In addition, it should be noted that the substrate layer 31 in this embodiment may be a flexible printed circuit board (FPC), and the pad layer 32 and the thickening layer 33 may be formed of a coverlay, such as: Polyethylene terephthalate (PET) cover film, Polyimide (PI) cover film or Photoimageable Coverlay (PIC), but not limited thereto; in some embodiments, The substrate layer 31 , the cushion layer 32 and the thickening layer 33 may be integrally formed.

Next, referring to FIG. 2 , the fixing method of the circuit board 3 on the frame 2 will be described. Since the fixing glue 6 is only disposed on the recessed portion 306, rather than sticking to the entire lower surface of the substrate layer 31, during assembly, the circuit board 3 and the frame 2 can be formed between the circuit board 3 and the frame 2 first as shown in FIG. 2(a). The inclination angle θ is used for alignment. At this time, the fixing glue 6 will not be in contact with the frame 2, so the circuit board 3 can still move. After confirming the sticking position, the circuit board 3 is put down again, and the fixing glue 6 sticks the circuit board 3 on the frame 2 to form the structure as shown in FIG. 2( b ). 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.

In more detail, the light emitting element 5 is disposed on the base layer 32 , and the area of the base layer 32 is preferably not smaller than the bottom surface area of the light emitting element 5 , so the base layer 32 can completely support the light emitting element 5 . In addition, the thickened layer 33 is located below the cushion layer 32 , and in the thickness direction D1 , the thickened layer 33 covers the range of the cushion layer 32 , so the thickened layer 33 can completely support the cushion layer 32 . Therefore, the above-mentioned structural design can ensure that the light-emitting element 5 is stably supported and kept horizontal without being inclined, so as to maintain the optimum light-emitting angle.

Referring to FIG. 1 again, after the positioning of the circuit board 3 is completed, the reflective sheet 7, the light guide plate 4 and the diaphragm 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 top layer 32 and the level difference between 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 is limited by the location of the reflective sheet, so the wiring area of the conventional circuit board is limited. 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 under the reflection sheet 7. Therefore, the substrate layer 31 is not limited by space, so the substrate layer can be increased or decreased according to the wiring requirements. 31 area. It should be noted that the step difference between the pad layer 32 and the substrate layer 31 (that is, the thickness of the pad layer 32 ) is less than or equal to the thickness of the reflective sheet 7 . By adjusting the thicknesses of the backing 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 shifting, so as to maintain the best light coupling effect.

Referring to FIG. 3 , a display device can be formed by disposing a display panel 9 on the light-emitting surface of the backlight module of the present invention.

With the aid of the above-mentioned structural design, the backlight module and the display device of the present invention have the following effects:

1. Improve the appearance of bad taste: the present invention uses the cushion layer 32 to elevate the light-emitting element 5, so that the light-emitting element 5 can be aligned with the light incident surface 41 of the light guide plate 4, so that the light of the light-emitting element 5 has the best optical coupling 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 element 5, and the light guide plate 4 can be There is only one reflective material below, thereby achieving the effect of improving the uniformity of light output, and improving the dark line caused by the joining of two materials or the bright halo problem caused by different reflectivity below the conventional light guide plate.

2. Improve the convenience of assembly: Since the fixing glue 6 is arranged in the recessed portion 306 instead of being attached to the entire lower surface of the substrate layer 31, the alignment and assembly of the circuit board 3 can be performed in an inclined manner, thereby improving alignment and assembly. , the convenience of heavy industry.

3. Increase the wiring area: Since the reflection sheet 7 is partially stacked on the substrate layer 31 of the circuit board 3 and the reflection sheet 7 and the substrate layer 31 are not on the same level, the reflection sheet 7 and the substrate layer 31 will not interfere with each other, so that the The size of the substrate layer 31 is increased to increase the wiring area of the substrate layer 31 .

To sum up, the backlight module and the display device of the present invention can make the light-emitting element 5 align with the light-incident surface 41 of the light guide plate 4 by means of the above-mentioned internal configuration, so that the light can have the best utilization rate and avoid the light-emitting element 5 efficiency loss, and the reflective sheet 7 can be extended to the edge of the light-emitting element 5, thereby reducing the problem of uneven appearance. In addition, the arrangement position of the fixing glue 6 can improve the convenience of alignment, assembly and rework of the circuit board 3 . Furthermore, since the reflection sheet 7 and the substrate layer 31 of the circuit board 3 do not interfere with each other, the wiring area can be increased, and the object of the present invention can be surely achieved.

The above descriptions are only preferred embodiments of the present invention, and should not limit the scope of implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the claims of the present invention and the contents of the description still belong to the scope of the patent of the present invention.

【List of reference numerals】

2 frames

3 circuit boards

301 First surface

302 Second surface

303 First end face

304 Second end face

305 Elevator

306 Recess

31 Substrate layer

32 Cushion Layers

33 Thickening layer

4 Light guide plate

41 Light incident surface

5 Lights

6 Fixing glue

7 Reflector

8 Diaphragm unit

9 Display panel

θ bevel

D1 Thickness direction.

Claims (10)

1. a backlight module, is characterized in that, comprises: frame; a circuit board, which is arranged 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 circuit board opposite to the first surface a second end surface of 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 disposed on the raised portion of the circuit board, the at least one light-emitting element being aligned with the light incident surface of the light guide plate; and a reflective sheet, which 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 part of the circuit board and the second between the end faces. 2 . The backlight module according to claim 1 , wherein one side of the second surface of the circuit board includes a concave portion disposed close to the second end surface, and the backlight module further includes a set The fixing glue in the recessed part, the fixing glue sticks the circuit board to the frame. 3 . The backlight module according to claim 2 , wherein the circuit board comprises a substrate layer and a pad layer disposed on one side of the substrate layer, and the pad layer is formed by the pad layer, 4 . The step difference between the cushion layer and the substrate layer is less than or equal to the thickness of the reflection sheet. 4 . The backlight module of claim 3 , wherein the reflective sheet extends to a level difference between the cushion layer and the substrate layer. 5 . 5 . The backlight module according to claim 3 , wherein the circuit board further comprises a thickening layer disposed on the other side of the substrate layer, and the thickening layer is located below the pad layer. 6 . , the recessed portion is formed by the step difference between the thickened layer and the substrate layer, and the thickness of the thickened layer is substantially the same as the thickness of the fixing glue. 6 . The backlight module according to claim 5 , wherein the area of the underlay layer is not less than the area of the bottom surface of the at least one light-emitting element. 7 . 7 . The backlight module of claim 6 , wherein, in the thickness direction, the thickened layer covers the range of the cushion layer. 8 . 8 . The backlight module according to claim 2 , wherein the recessed portion and the raised portion do not overlap in a thickness direction. 9 . 9 . The backlight module of claim 1 , further comprising a film unit disposed on the light exit side of the light guide plate. 10 . 10 . A display device, comprising the backlight module according to any one of claims 1 to 9 and a display panel disposed on a light-emitting surface of the backlight module. 11 .

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