TWI533058B - Backlight module - Google Patents

Description

Backlight module

The invention relates to a backlight module, and in particular to a backlight module with uniform light emission.

The backlight module is a key component in the liquid crystal display. Since the liquid crystal itself does not emit light, the backlight module is used to provide sufficient light intensity and a uniformly distributed light source, so that the liquid crystal display panel has the function of displaying images. The backlight module can be generally divided into an edge lighting backlight module and a bottom lighting backlight module. The edge light backlight module usually has a side incident light source design, and has a light weight. Thin, low-power features are often preferred for mobile phones, Personal Digital Assistants (PDAs), and notebook screens. In addition, since the light emitting diode (LED) has high energy efficiency and long service life, the light emitting diode is often used as a light source of the backlight module.

Please refer to FIG. 1 , which is a partial schematic view of a conventional edge-lit backlight module. As can be clearly seen from the figure, the conventional edge-lit backlight module 1 includes a light guide plate 10 and a plurality of light-emitting diodes 11 , wherein the light-emitting diodes 11 are disposed equidistantly disposed on the light guide plate 10 . Beside the light side 12. However, such a configuration arrangement often causes a problem of the light-emitting divergence angle of the light-emitting diode 11 , which causes the entire liquid crystal display panel (not shown) to have an obvious interval dark line due to uneven display brightness, thereby causing various display abnormalities ( Mura). Therefore, how to improve the uniformity of illumination of the conventional side-light backlight module is one of the topics currently concerned by related industries.

In view of the above, an object of the present invention is to provide a backlight module that can uniformly emit light to improve the display quality of the liquid crystal display panel.

The invention provides a backlight module, which comprises a light guide plate, a first light source and a second light source. The light guide plate has a light incident surface and a light exit surface. The first light source is disposed beside the light incident surface and is adapted to emit light into the light guide plate along the first light exiting direction. The second light source is stacked above the first light source, and is adapted to emit light into the light guide plate along the second light exiting direction, and the first light emitting direction and the normal line of the light incident surface have a first angle, and the second light emitting direction and the light entering the light There is a second angle between the normals of the faces.

In an embodiment of the invention, the first light source comprises a plurality of first light emitting elements, and the second light source comprises a plurality of second light emitting elements. Each of the second light emitting elements is respectively stacked on the corresponding first light emitting element.

In an embodiment of the invention, the first angle and the second angle are between 0 degrees and 90 degrees.

In an embodiment of the invention, the light incident surface of the light guide plate has a first light incident portion and a second light incident portion, wherein the first light incident portion is substantially perpendicular to the first light exiting direction, and the second light incident portion is substantially vertical. The second light exit direction.

In an embodiment of the invention, the light incident surface of the light guide plate has at least one groove, and the first light source and the second light source are stuck in the groove.

In an embodiment of the invention, the groove has a first inner wall and a second inner wall, wherein the first inner wall is substantially perpendicular to the first light exiting direction, and the second inner wall is substantially perpendicular to the second light exiting direction.

The backlight module of the embodiment of the present invention mainly configures the first light source and the second light source to be stacked above the light incident surface, and the light directions of the first light source and the second light source are different, and respectively, and the light guide plate The normal clip of the entrance surface has an angle. Therefore, the backlight module of the present invention can provide a uniform surface light source, thereby improving the display quality of the liquid crystal display panel.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

It can be clearly seen from the foregoing that the uneven illumination of the backlight module can produce a clear interval of dark lines on the liquid crystal display panel, and the present invention addresses the problem, and further clarifies the following embodiments to solve the conventional technical means. The problem that arises.

Please refer to FIG. 2 , which is a schematic diagram of an embodiment of a backlight module developed by the present invention to improve the lack of the prior art. The backlight module described in the embodiment is a side-lit type. The backlight module will be described as an example. As can be clearly seen from the figure, the edge-lit backlight module 2 of the present embodiment mainly includes a light guide plate 20, a first light source 21, and a second light source 22. The light guide plate 20 has a light-incident surface 201 and a light-emitting surface 202. The first light source 21 is disposed, for example, beside the light incident surface 201 of the light guide plate 20, and emits light to the inside of the light guide plate 20 along the first light exit direction A. The second light source 22 is stacked above the first light source 21 and emits light to the inside of the light guide plate 20 along the second light exiting direction B. In this embodiment, the first light-emitting direction A and the normal line C of the light-incident surface 201 have a first angle θ1, which is, for example, greater than 0 degrees and less than 90 degrees, and the second light-emitting direction B is opposite to the light-incident surface. The normal line C of 201 has a second included angle θ2 which is, for example, greater than 0 degrees and less than 90 degrees.

Since the light directions of the first light source 21 and the second light source 22 stacked on each other are different, the first light source 21 and the second light source 22 respectively emit light along the first light exiting direction A and the second splitting direction B, and penetrate into the light. After the surface 201 enters the light guide plate 20, the light is uniformly emitted by the light exit surface 202 of the light guide plate 20. Therefore, by using the liquid crystal display (not shown) of the backlight module 2, a surface light source with uniform illumination can be obtained, and the image displayed thereon can be prevented from having obvious bright/dark lines, thereby improving display quality. The detailed construction of the edge-lit backlight module 2 described in this embodiment will be further described below.

Please refer to FIG. 3 , which is a schematic exploded view of the edge-lit backlight module 2 of the embodiment. As can be clearly seen from the figure, the first light source 21 is composed of, for example, a plurality of light-emitting elements 211, 212, 213 (such as light-emitting diodes) (in the description of the embodiment, only three light-emitting elements are taken as an example. To illustrate, the actual number of light-emitting elements required depends on the type of liquid crystal display panel, backlight module, size, etc., and the second light source 22 is also composed of a plurality of light-emitting elements 221, 222, and 223 (such as a light-emitting diode). Body). As shown in FIG. 3, the light-emitting elements 211, 212, 213 constituting the first light source 21 and the light-emitting elements 221, 222, 223 constituting the second light source 22 are stacked opposite each other (for example, the light-emitting elements 221 are stacked on the light-emitting element 211). Above, and so on).

Further, the light-emitting elements 211, 212, 213, 221, 222, and 223 which are stacked opposite each other are disposed, for example, on the same circuit board (not shown). That is, the first light source 21 and the second light source 22 belong to the same light bar. Of course, in other embodiments, the first light source 21 and the second light source 22 may be disposed on different circuit boards, that is, the first light source 21 and the second light source 22 are respectively used as different light strips, so as to facilitate When these light-emitting elements fail, the defective light-emitting elements are separately replaced for maintenance.

Referring to the above technical description, please refer to the exploded view of the component shown in FIG. 3. As shown in the figure, in order to increase the utilization rate of the light emitted by the first light source 21 and the second light source 22, the light source 20 is sufficiently incident on the light guide plate 20. The light incident surface 201 of the light guide plate 20 of the present embodiment has, for example, a first light incident portion 2011 and a second light incident portion 2012, wherein the first light incident portion 2011 substantially corresponds to the first light exit direction of the first light source 21 A is vertical, and the second light incident portion 2012 is substantially perpendicular to the second light exiting direction B of the second light source 22. Specifically, in this embodiment, for example, the light incident surface 201 of the light guide plate 20 is provided with a recess 23 that can provide the first light source 21 and the second light source 22, and the number of the recesses 23 depends on The number of light-emitting elements respectively possessed by the first light source 21 and the second light source 22 depends on the number of light-emitting elements. In the description of the embodiment, the light guide plate 20 is provided with three recesses 23 on the light incident surface 201 for respectively accommodating the light emitting elements 211, 221, the light emitting elements 212, 222, and the light emitting elements 213, 223. Each of the grooves 23 has a first inner wall 231 perpendicular to the first light exit direction A and a second inner wall 232 perpendicular to the second light exit direction B. That is, the first inner wall 231 of the groove is the first light incident portion 2011, and the second inner wall 232 is the second light incident portion 2012.

More specifically, the above-mentioned groove 23 includes a first recess (that is, a position of the first light incident portion 2011) and a second recess (that is, a position of the second light incident portion 2012), and the second recess is stacked on the first Above the recess, the first recess is recessed to form a first end point P1 and a first inner wall 231, and the second recess is recessed to form a second end point P2 and a second inner wall 232, the vertical projection of the first end point and The vertical projections of the second end point do not overlap each other, the first light source 21 is stuck in the first recess and is attached to the first inner wall 231 from the first end, and the second light source 22 is stuck in the second recess and from the second end The second inner wall 232 is attached to the point.

In addition, the angles of the light-emitting elements 211, 212, 213, 221, 222, and 223 which are stacked relative to each other may be arbitrarily changed according to the design, that is, the present invention does not limit the plurality of light-emitting elements 211 of the first light source 21. 212, 213 must be arranged in parallel, and the plurality of light-emitting elements 221, 222, 223 of the second light source 22 are not necessarily arranged in parallel.

And the direction of the first inner wall 231 and the second inner wall 232 of each groove 23 The arrangement angles of the light-emitting elements 211, 212, 213, 221, 222, and 223 may also be different, such that the first inner wall 231 is perpendicular to the first light-emitting direction A, and the second inner wall 232 is perpendicular to the second light-emitting direction B. .

It can be clearly understood from the above technical description that the backlight module of the present invention provides light through a plurality of sets of light sources stacked on top of each other and having different light-emitting directions, and converts the light into a uniform surface light source by the light guide plate. Further, the display quality of the liquid crystal display panel using the backlight module is improved.

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

1‧‧‧Knowledge side light backlight module

10‧‧‧Light guide plate

11‧‧‧Lighting diode

12‧‧‧Into the glossy surface

2‧‧‧Side-light backlight module

20‧‧‧Light guide

21‧‧‧First light source

22‧‧‧second light source

23‧‧‧ Groove

231‧‧‧First inner wall

232‧‧‧Second inner wall

201‧‧‧Into the glossy surface

2011‧‧‧The first light department

2012‧‧‧Second Light Department

202‧‧‧Glossy surface

211, 212, 213, 221, 222, 223‧‧ ‧Lighting elements

A‧‧‧The first light direction

B‧‧‧Second light direction

C‧‧‧ normal

Θ1‧‧‧ first angle

Θ2‧‧‧second angle

P1‧‧‧ first endpoint

P2‧‧‧ second endpoint

FIG. 1 is a schematic view showing a configuration of a light guide plate and a light emitting diode included in a conventional backlight module.

2 is a schematic structural view of an edge-lit backlight module according to a preferred embodiment of the present invention.

3 is an exploded perspective view of the edge-lit backlight module of the preferred embodiment of the present invention.

2. . . Sidelight backlight module

20. . . Light guide

twenty one. . . First light source

twenty two. . . Second light source

twenty three. . . Groove

231. . . First inner wall

232. . . Second inner wall

201. . . Glossy surface

2011. . . First light entrance

2012. . . Second light entrance

202. . . Glossy surface

211, 212, 213, 221, 222, 223. . . Light-emitting element

A. . . First light direction

B. . . Second light direction

C. . . Normal

Θ1. . . First angle

Θ2. . . Second angle

Claims (5)

A backlight module includes: a light guide plate having a light incident surface and a light exiting surface, wherein the light incident surface has at least one groove, the groove includes a first concave portion and a second concave portion, the second concave portion Stacked on the first recessed portion, the first recessed portion is recessed to form a first end point and a first inner wall, and the second recessed portion is recessed to form a second end point and a second inner wall. The vertical projection of the first end point and the vertical projection of the second end point do not overlap each other; a first light source is disposed in the first recess and fits the first inner wall from the first end point, suitable for a first light emitting direction emits light into the light guide plate; and a second light source is disposed in the second concave portion and fits the second inner wall from the second end point, and is stacked above the first light source, Suitable for emitting light into the light guide plate along a second light exiting direction, wherein the first light exiting direction and the normal line of the light incident surface have a first angle, the second light emitting direction and the light incident surface There is a second angle between the lines. The backlight module of claim 1, wherein the first light source comprises a plurality of first light emitting elements, and the second light source comprises a plurality of second light emitting elements, each of the second light emitting elements being stacked thereon Corresponding to the first light-emitting element. The backlight module of claim 1, wherein the first angle is greater than 0 degrees and less than 90 degrees. The backlight module of claim 1, wherein the second angle is greater than 0 degrees and less than 90 degrees. The backlight module of claim 1, wherein the first inner wall is substantially perpendicular to the first light exiting direction, and the second inner wall is substantially perpendicular to the second light exiting direction.