TW201409128A - Display device and back light module thereof - Google Patents

Abstract

A back light module includes a light guide plate, a flexible print circuit, a plurality of light sources, and a combined tape. The light guide plate has a first surface and a second surface adjacent to the first surface. The flexible print circuit disposes on the first surface. Those light sources dispose on the flexible print circuit and face the second surface. The combined tape disposes between the first surface and the flexible print circuit. The combined tape comprises a glue layer and a washer. The washer disposes on one end of the glue layer far away the second surface. The width of the washer is smaller than that of the glue layer.

Description

Display device and backlight module thereof

The invention relates to an electronic device, in particular to a display device with a backlight module and a backlight module thereof.

For the rapid advancement of the multimedia society, most of them benefit from the rapid development of semiconductor components or display devices. In terms of display devices, cathode display tubes (or cathode tubes, Cathode Ray Tube, CRT) have always dominated the display market due to their excellent display quality and economy. However, CRTs have the problem of excessive volume and excessive energy consumption. For high image quality, low power consumption, thin mass production, low voltage driving, small size, etc., CRT-type displays obviously cannot achieve this requirement. In view of this, liquid crystal display (LCD) will have great advantages, and LCD has been widely used in small and medium-sized portable TVs, video phones, video recorders, notebook computers, and tables. Top-size displays, tablets, and projection color TVs.

Taking a liquid crystal display as an example, it includes a backlight module. The backlight module comprises a light guide plate and a light source module, and the light source module comprises a flexible circuit board and a light source disposed on the flexible circuit board. The flexible circuit board is provided with a glue layer, and the flexible circuit board is adhered to the light guide plate through the adhesive layer so that the light source can fix the light incident surface of the light guide plate.

However, since the adhesive layer adheres to the light guide plate, when the light of the light source is applied to the surface of the adhesive layer, the energy of the light will be absorbed by the adhesive layer and consumed. As a result, the optical efficiency of the backlight module will be reduced. In this regard, The rubber layer is designed in a segmented manner to avoid loss of light energy, but this will also make the adhesive layer difficult to lay and adhere to the flexible circuit board, resulting in an increase in the defective rate of the backlight module during production.

The invention provides a display device and a backlight module thereof, thereby reducing the defect rate of the backlight module during production and improving the optical efficiency of the backlight module.

The backlight module disclosed in the present invention comprises a light guide plate, a flexible circuit board, a plurality of light sources and a composite patch. The light guide plate has adjacent first and second faces. The flexible circuit board is disposed on the first side. These light sources are placed on a flexible circuit board and these light sources face the second side. The composite patch is disposed between the first surface and the flexible circuit board. The composite patch has a glue layer and a gasket. The gasket is located at one end of the glue layer away from the second surface, and the width of the gasket is smaller than the width of the rubber layer. .

The display device disclosed in the present invention comprises a frame, a backlight module, an optical film and a display panel. The backlight module is disposed on the frame. The backlight module includes a light guide plate, a flexible circuit board, a plurality of light sources, and a composite patch. The light guide plate has adjacent first and second faces. The flexible circuit board is disposed on the first side. These light sources are placed on a flexible circuit board and these light sources face the second side. The composite patch is disposed between the first surface and the flexible circuit board. The composite patch has a glue layer and a gasket. The gasket is located at one end of the glue layer away from the second surface, and the width of the gasket is smaller than the width of the rubber layer. . The optical film is stacked on the light guide plate. The display panel is stacked on the optical film.

According to the display device and the backlight module thereof, the width of the spacer is smaller than the width of the adhesive layer, and the spacer is disposed between the body of the adhesive layer and the light guide plate. Between one side, the glue layer is only partially (extended) adhered to the light guide plate. In this way, the problem that the energy of the light is absorbed by the adhesive layer and the consumption is reduced can be reduced.

The features, implementations, and utilities of the present invention are described in detail below with reference to the drawings.

1 and 2C, FIG. 1 is a cross-sectional view showing a structure of a display device according to an embodiment of the present invention, and FIG. 2A is a cross-sectional view showing a structure of a backlight module according to FIG. 1, and FIG. 2B is based on Fig. 2A is a partial structural exploded view, and Fig. 2C is a partial structural front view according to Fig. 2A.

The display device 10 of this embodiment can be applied to a tablet computer or a liquid crystal screen, but is not limited thereto. The display device 10 includes a housing 11 , a backlight module 20 , an optical film 12 , and a display panel 13 .

The backlight module 20 is disposed on the housing 11 . The backlight module 20 includes a light guide plate 24, a circuit board 21, a plurality of light sources 22, and a composite patch 23.

The light guide plate 24 has a first surface 241, a second surface 242, and a third surface 243. The first surface 241 and the third surface 243 are located on opposite sides of the light guide plate 24. The second surface 242 is between the first surface 241 and the third surface 243 , and the second surface 242 is adjacent to the first surface 241 and the third surface 243 . Further, the third surface 243 of the light guide plate 24 of the present embodiment faces the frame 11, and the second surface 242 faces the light source 22. Further, the second surface 242 is used as a light incident surface of the light guide plate 24, and the first surface 241 is used as a light exit surface of the light guide plate 24.

The circuit board 21 can be a flexible printed circuit (FPC), and the circuit board 21 is disposed on the periphery of the first surface 241 of the light guide plate 24. These light sources 22 are provided The light-emitting surface 221 of the light source 22 faces the second surface 242 of the light guide plate 24. These light sources 22 can be, but are not limited to, light emitting diodes (LEDs).

The composite patch 23 is interposed between the first surface 241 of the light guide plate 24 and the flexible circuit board 21. The composite patch 23 has a glue layer 231 and a spacer 232 as shown in FIG. 2B. The spacer 232 is located at one end of the adhesive layer 231 away from the second surface 242, and the width W2 of the spacer 232 is smaller than the width W1 of the adhesive layer 231. The material of the gasket 232 may be, but not limited to, polyethylene terephthalate (PET).

In more detail, the glue layer 231 includes a body 2311 and a plurality of extensions 2312 protruding from one side of the body 2311. The width W1 of the adhesive layer 231 is a distance from the body 2311 to the extension portion 2312 away from one side of the body 2311. The width W3 of the body 2311 of the adhesive layer 231 is substantially equal to the width W2 of the spacer 232, and the outer shape of the body 2311 of the adhesive layer 231 is matched to the outer shape of the spacer 232. It should be noted that, in this embodiment, the width W3 of the body 2311 is equal to the width W2 of the spacer 232, but is not limited thereto. For example, in other embodiments, the width W3 of the body 2311 may also be greater than the width W2 of the spacer 232. In this embodiment, the outer shape of the body 2311 of the rubber layer 231 and the outer shape of the spacer 232 are substantially rectangular, but not limited thereto. The spacers 232 are stacked on the body 2311 of the adhesive layer 231 such that the extensions 2312 protrude from the one side of the body 2311 with respect to the spacer 232, and the distance from the extensions 2312 to the second surface 242 is smaller than the spacers 232 to The distance of the second face 242.

The opposite sides of the body 2311 of the adhesive layer 231 are respectively adhered to the spacer 232 and the flexible circuit board 21, that is, the body 2311 of the adhesive layer 231 is adhered to the spacer 232 and the flexible circuit. Between the boards 21. In addition, the spacer 232 is disposed between the body 2311 of the adhesive layer 231 and the first surface 241 of the light guide plate 24 such that the body 2311 of the adhesive layer 231 does not contact the first surface 241 of the light guide plate 24. In this way, the energy of the light emitted by the light source 22 can be prevented from being absorbed by the body 2311 of the adhesive layer 231 and weakened. Also, since the spacer 232 is not adhered to the body 2311, a medium having air between the spacer 232 and the body 2311 exists. In this way, the spacer 232 will also not affect the total reflection effect of the light in the body 2311, so that the energy of the light emitted by the light source 22 is not absorbed by the spacer 232 and is weakened.

In addition, each of the extending portions 2312 is interposed between the adjacent two light sources 22 (as shown in FIG. 2C ), and the extending portions 2312 are adhered between the flexible circuit board 21 and the first surface 241 of the light guide plate 24 . In other words, the light guide plate 24 and the flexible circuit board 21 are bonded only by the extension portion 2312 of the adhesive layer 231. Moreover, since the extending portion 2312 is interposed between the adjacent two light sources 22, the energy of the light emitted by the light source 22 can be prevented from being absorbed by the extending portion 2312 of the adhesive layer 231.

In addition, in the embodiment, the backlight module 20 may further include a reflective sheet 25 disposed on the third surface 243 of the light guide plate 24 , and the reflective sheet 25 is interposed between the frame 11 and the light guide plate 24 . Furthermore, the reflective sheet 25 and the flexible circuit board 21 are respectively disposed on opposite sides of the light guide plate 24. The reflection sheet 25 is for allowing the light emitted from the light source 22 into the light guide plate 24 to be uniformly emitted from the first surface 241 of the light guide plate 24.

The optical film 12 may be, for example, a diffusion sheet, a brightness enhancement sheet, or a composite film formed by stacking two or more of a diffusion sheet and a brightness enhancement sheet. The optical film 12 is stacked on the guide On the first side 241 of the light panel 24, the optical film 12 is used to enhance or homogenize the light generated by the backlight module 20 to enhance the overall optical efficiency.

The display panel 13 is stacked on the optical film 12 such that the optical film 12 is interposed between the display panel 13 and the light guide plate 24.

According to the above, since the width of the spacer 232 is smaller than the width of the adhesive layer 231, and the spacer 232 is interposed between the body 2311 of the adhesive layer 231 and the first surface 241 of the light guide plate 24, the adhesive layer 231 is only partially adhered to the light guide plate. 24 (only adhered to the light guide plate 24 through the extension portion 2312). Moreover, each extension 2312 is interposed between two adjacent light sources 22. In this way, the problem that the energy of the light is absorbed by the adhesive layer 231 and the consumption is reduced can be reduced. The overall brightness of the backlight module 20 of the present invention can be increased by more than 13% compared with the conventional brightness of the conventional backlight module, as compared with the backlight module in which the conventional embodiment of the present invention is adhered to the light guide plate.

In addition, since the extending portions 2312 of the adhesive layers 231 are connected by the body 2311 of the adhesive layer 231, the adhesive layer 231 of the embodiment is integrally designed to facilitate the adhesive layer 231 to be laid and adhered to the flexible circuit board 21. In order to reduce the defect rate of the backlight module 20 during assembly.

Please continue to refer to Figures 2B and 2C. Furthermore, in the present embodiment, the extension portion 2312 of the adhesive layer 231 may have a substantially trapezoidal shape, and one end away from the body 2311 has a large width. Each of the extending portions 2312 has opposite side edges 2313. The two side edges 2313 are sandwiched by an angle θ, and the angle θ may range from 0 degrees to 120 degrees. Moreover, the distance between the two side edges 2313 is gradually reduced toward the direction of the body 2311 or the spacer 232. It is worth mentioning that the two sides 2313 of each extension 2312 are sandwiched. The angle θ corresponds to the range of the light exit angle of the light source 22. For example, if the light exit angle of the light source 22 is 60 degrees, the angle θ between the two sides 2313 of the extending portion 2312 needs to be greater than or equal to 60 degrees. In this way, it can be ensured that the extending portion 2312 of the adhesive layer 231 can avoid the illuminated area of the light source 22, so as to avoid the problem that the light energy is absorbed by the extending portion 2312 of the adhesive layer 231 and the consumption is reduced.

It should be noted that the extension of the adhesive layer 231 described above is not intended to limit the present invention. For example, in other embodiments, the extension 2312' of the glue layer 231' may also be substantially rectangular (as shown in FIG. 3), as long as the extension 2312' can be avoided from the illumination area of the light source 22. Just fine.

Continuing to refer to FIG. 1 and FIG. 2A , in the present embodiment, the thickness D1 of the light guide plate 24 adjacent to the one end of the second surface 242 may be greater than the thickness D2 of the light guide plate 24 away from one end of the second surface 242 . In this way, by the design of the thickness of the light guide plate 24, the thickness of the composite patch 23 having one side of the spacer 232 can be offset to maintain the flatness of the flexible circuit board 21 disposed on the light guide plate 24.

It should be noted that the design of the thickness of the above-mentioned light guide plate 24 is not intended to limit the present invention. Since the thickness of the spacer 232 is extremely small, in other embodiments, the light guide plate 24 may have a uniform thickness, and the gap generated by the thickness of the spacer 232 does not affect the flexible circuit board 21 and the light guide plate 24. The combined effect has a substantial negative impact.

Please refer to FIG. 4, which is a cross-sectional view showing the structure of a display device according to another embodiment of the present invention. Since this embodiment is similar to the embodiment of Fig. 1, the same structure will not be described in detail.

The display device 10a of the present embodiment includes a housing 11, a backlight module 20a, an optical film 12, and a display panel 13. The backlight module 20a is disposed on the housing 11. The backlight module 20a includes a light guide plate 24a, a flexible circuit board 21a, a plurality of light sources 22, and a composite patch 23a. The light guide plate 24a has a first surface 241a, a second surface 242a, and a third surface 243a. The first surface 241a and the third surface 243a are located on opposite sides of the light guide plate 24a, and the second surface 242a is adjacent to the first surface 241a and the third surface 243a. Further, the first surface 241a of the light guide plate 24a of the present embodiment faces the frame 11a, and the second surface 242a faces the light source 22. Further, the second surface 242a serves as a light incident surface of the light guide plate 24a, and the third surface 243a serves as a light exit surface of the light guide plate 24a.

The flexible circuit board 21a is disposed on the first surface 241a of the light guide plate 24a, and the flexible circuit board 21a is interposed between the light guide plate 24a and the housing 11. These light sources 22 are disposed on the flexible circuit board 21a, and the light emitting surface 221 of these light sources 22 faces the second surface 242a.

The composite patch 23a is interposed between the first surface 241a of the light guide plate 24a and the flexible circuit board 21a. The composite patch 23a has a glue layer 231a and a spacer 232a. The reflection sheet 25a is disposed on the first surface 241a of the light guide plate 24a, and the reflection sheet 25a is interposed between the frame 11 and the light guide plate 24a. Furthermore, the reflection sheet 25a and the flexible circuit board 21a are respectively disposed on the same side of the light guide plate 24a.

Further, the difference between this embodiment and the embodiment of FIG. 1 lies in the relative position between the flexible circuit board 21a, the composite patch 23a, the light guide plate 24a and the reflection sheet 25a, and the above-mentioned difference characteristics do not affect the present case. efficacy.

The display device and the backlight module thereof according to the above embodiments are characterized in that the width of the spacer is smaller than the width of the adhesive layer, and the spacer is disposed between the body of the adhesive layer and the first surface of the light guide plate. In between, the glue layer is only partially (extended) adhered to the light guide plate. In this way, the problem that the energy of the light is absorbed by the adhesive layer and the consumption is reduced can be reduced.

In addition, since the extension of the adhesive layer is connected by the body of the adhesive layer, the adhesive layer is integrally designed to facilitate the adhesive layer to be laid and adhered to the flexible circuit board, so as to reduce the defect rate of the backlight module during assembly.

While the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The patent protection scope of the invention is subject to the definition of the scope of the patent application attached to the specification.

10‧‧‧ display device

10a‧‧‧Display device

11‧‧‧ frame

11a‧‧‧ frame

12‧‧‧Optical diaphragm

12a‧‧‧Optical diaphragm

13‧‧‧ display panel

13a‧‧‧ display panel

20‧‧‧Backlight module

20a‧‧‧Backlight module

21‧‧‧ boards

21a‧‧‧Board

22‧‧‧Light source

221‧‧‧Lighting surface

23‧‧‧Composite patch

23a‧‧‧Composite patch

231‧‧‧ glue layer

231a‧‧‧ glue layer

2311‧‧‧ Ontology

2312‧‧‧Extension

2313‧‧‧ side

232‧‧‧shims

232a‧‧‧shims

24‧‧‧Light guide

24a‧‧‧Light guide

241‧‧‧ first side

241a‧‧‧ first side

242‧‧‧ second side

242a‧‧‧ second side

243‧‧‧ third side

243a‧‧‧ third side

25‧‧‧reflector

1 is a cross-sectional view showing the structure of a display device according to an embodiment of the present invention.

Fig. 2A is a cross-sectional view showing the structure of the backlight module according to Fig. 1.

Fig. 2B is an exploded view of the partial structure according to Fig. 2A.

Fig. 2C is a front view of a partial structure according to Fig. 2A.

Figure 3 is a front elevational view of a subbing layer in accordance with another embodiment of the present invention.

Figure 4 is a cross-sectional view showing the structure of a display device according to another embodiment of the present invention.

10‧‧‧ display device

11‧‧‧ frame

12‧‧‧Optical diaphragm

13‧‧‧ display panel

20‧‧‧Backlight module

21‧‧‧ boards

22‧‧‧Light source

221‧‧‧Lighting surface

23‧‧‧Composite patch

231‧‧‧ glue layer

232‧‧‧shims

24‧‧‧Light guide

241‧‧‧ first side

242‧‧‧ second side

243‧‧‧ third side

25‧‧‧reflector

Claims (14)

A backlight module includes: a light guide plate having an adjacent first surface and a second surface; a circuit board disposed on the first surface; a plurality of light sources disposed on the circuit board, and the light sources The light emitting surface faces the second surface; and a composite patch is disposed between the first surface and the circuit board, the composite patch has a glue layer and a gasket, and the gasket is located on the glue layer Far from one end of the second face, and the width of the spacer is less than the width of the glue layer. The backlight module of claim 1, wherein the adhesive layer has a plurality of extensions protruding from a side of the spacer, each of the extensions being between the adjacent two of the light sources, and the The extensions are adhered between the circuit board and the light guide plate. The backlight module of claim 2, wherein the adhesive layer further comprises a body, the extensions protrude from a side of the body, the spacer is interposed between the body and the light guide plate, and the body is adhered to Between the board and the spacer. The backlight module of claim 2, wherein the opposite sides of the extension of the adhesive layer are at an angle ranging from 0 degrees to 120 degrees. The backlight module of claim 1, wherein a thickness of the light guide plate adjacent to one end of the second surface is greater than a thickness of the light guide plate away from one end of the second surface. The backlight module of claim 1, further comprising a reflective sheet, wherein the light guide plate has a third surface opposite to the first surface, and the reflective sheet is disposed on the third surface. The backlight module of claim 1, further comprising a reflective sheet disposed on the first surface. A display device comprising: a frame; a backlight module disposed on the frame, comprising: a light guide plate having an adjacent first surface and a second surface; a circuit board disposed on the first a plurality of light sources disposed on the circuit board, wherein the light sources face the second surface; and a composite patch disposed between the first surface and the circuit board, the composite patch having a a glue layer and a gasket, the gasket is located at one end of the glue layer away from the second surface, and the width of the gasket is smaller than the width of the glue layer; an optical film stacked on the light guide plate; A display panel is stacked on the optical film. The display device of claim 8, wherein the adhesive layer has a plurality of extensions protruding from a side of the spacer, each of the extensions being between the adjacent two of the light sources, and the The extension is adhered between the circuit board and the light guide plate. The display device of claim 9, wherein the adhesive layer further comprises a body protruding from a side of the body, the spacer being interposed between the body and the light guide plate, the body being adhered to the Between the board and the spacer. The display device of claim 9, wherein the opposite sides of the extension of the adhesive layer are at an angle ranging from 0 degrees to 120 degrees. The display device of claim 8, wherein a thickness of one end of the light guide plate adjacent to the second surface is greater than a thickness of the light guide plate away from one end of the second surface. The display device of claim 8, wherein the backlight module further comprises a reflective sheet, and the light guide plate has a third surface opposite to the first surface, the reflective sheet is disposed on the third surface, and the reflective sheet is disposed on the third surface The reflective sheet is interposed between the frame and the light guide plate. The display device of claim 8, wherein the backlight module further comprises a reflective sheet disposed on the first surface, and the reflective sheet is interposed between the frame and the light guide plate.