TWI382244B - Direct type backlight module - Google Patents

Description

Direct type backlight module

The invention relates to a backlight module applied to a liquid crystal display, in particular to a direct type backlight module using a point light source.

In recent years, liquid crystal displays have been widely used due to their characteristics of lightness, thinness, small size and low power consumption. Since the liquid crystal display panel itself does not have the light-emitting property, the backlight module is required to provide a backlight to realize the display function of the liquid crystal display panel.

Referring to FIG. 1 , a backlight module 10 includes a frame 11 , a reflective sheet 14 , an optical plate 15 , and a plurality of point light sources 13 . The frame 11 includes a bottom plate 111 and a plurality of side walls 113 extending from the edge of the bottom plate 111 to the same side. The bottom plate 111 and the plurality of side walls 113 form a cavity. The plurality of point light sources 13 are arranged on the bottom plate 111. The optical plate 15 is disposed on the top of the plurality of side walls 113. The reflection sheet 14 is provided with a plurality of through holes 141 corresponding to the point light source 13, and the light emitting portion 131 of the plurality of point light sources 13 transmits a light beam to the optical plate 15 through the corresponding through holes 141.

In the backlight module 10, the light-emitting portion 131 of the point light source 13 directly faces the optical plate 15, and a light spot with a strong light intensity is often formed on the optical plate 15, so that the light uniformity of the backlight module 10 is poor.

In view of the above situation, it is necessary to provide a direct-lit backlight module with uniform light output.

A direct type backlight module includes an optical plate, a plurality of point sources, and a reflective element. The optical plate includes a light emitting surface and a light emitting surface Put it into the glossy side. The plurality of point sources are disposed between the reflective element and the light incident surface of the optical plate. The direct-type backlight module includes a plurality of strip-shaped flexible circuit boards attached to the light-incident surface of the optical board, and a plurality of point light sources are disposed at edges of the flexible circuit board. The complex point source directly faces the reflective element, and the reflective element is formed with a plurality of reflective curved surfaces corresponding to the point source.

In the backlight module, the point source directly faces the reflective element, and the reflective element forms a plurality of reflective curved surfaces corresponding to the point source, and at least part of the light emitted by the point source directly hits the reflective surface, by the reflection After the surface is adjusted, it is directed to the optical plate to prevent all the light emitted by the light source from directly hitting the optical plate to form a spot with strong light intensity. Therefore, the backlight module has the advantage of uniform light output.

The backlight module of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Referring to FIG. 2 and FIG. 3 simultaneously, a preferred embodiment of the backlight module of the present invention provides a backlight module 30. The backlight module 30 includes a frame 31, a plurality of strip-shaped flexible circuit boards 33, a plurality of point light sources 35, and an optical plate 37.

The frame 31 includes a bottom plate 311 and four side walls 313 extending from the edge of the bottom plate 311 toward the same side. The bottom plate 311 and the four side walls 313 define a cavity (not shown). A plurality of reflective curved surfaces 3111 are formed on the bottom plate 311. In this embodiment, the reflective curved surface 3111 is a spherical concave surface.

The width D of the flexible circuit board 33 is generally less than 5 mm. In this embodiment, the point light source 35 is an edge light type light emitting diode. The optical plate 37 is made of a transparent resin material The composition includes a light emitting surface 371 and a light incident surface 373 opposite to the light emitting surface 371.

When assembled, the complex point light source 35 is disposed at the edge of the flexible circuit board 33, and the flexible circuit board 33 is attached to the light incident surface 373 of the optical plate 37. Then, the optical plate 37 is disposed on the top of the side wall 313 of the frame 31 and closes the frame 31. The cavity, and each point source 35 has a one-to-one correspondence with the reflective curved surface 3111 of the bottom plate 311. In this embodiment, each point light source 35 directly faces the bottom plate 311 of the frame 31, and each point light source 35 corresponds to the center of the spherical concave surface of the reflective curved surface 3111.

When in use, the point source 35 emits light. Since the point light source 35 is an edge light-emitting diode, part of the light that is directed toward the optical plate 37 is substantially directly emitted through the optical plate 37, and part of the light that is emitted toward the frame 31 first reaches the reflective curved surface 3111, and is reflected to the optical surface by the reflective curved surface 3111. The plate 37 is again emitted.

Since the frame 31 is formed with the reflective curved surface 3111, the light emitted by the point light source 35 is projected to a different point on the reflective curved surface 3111, and the corresponding light is different from the angle formed by the corresponding reflective curved surface 3111. For example, the reflective curved surface 3111 can be emitted toward the frame 31. The line is reflected to the periphery of the point source 35, so that a surface light source having a light intensity substantially equal to a portion of the light directly directed toward the optical plate 37 is formed, thereby avoiding the formation of a spot of high light intensity on the optical plate 37. Therefore, the backlight module 30 has the advantage of uniform light emission.

It should be emphasized that since the width D of the flexible circuit board 33 is small, generally less than 5 mm, the point light source 35 is disposed at the edge of the flexible circuit board 33, and part of the light emitted by the point light source 35 can be obtained by the flexible circuit board 33 and the optical board 37. Handover The area where the optical plate 37 is covered by the flexible circuit board 33 is diffused to avoid formation of the strip of the flexible circuit board 33.

In the backlight module 30, the bottom plate 311 and the side wall 313 are integrally formed. When the optical plate 37 is disposed on the top of the side wall 313, the bottom plate 311, the side wall 313 and the optical plate 37 enclose a closed cavity. The advantage of impurities such as dust entering.

In this embodiment, the bottom plate 311 is a reflective element, and a plurality of reflective curved surfaces 3111 are formed thereon, and a plurality of reflective curved surfaces may be formed on the reflective surface of a single reflective element. In this way, it is only necessary to arrange the reflective element having the reflective curved surface at the bottom of the frame and to make the complex reflective curved surface correspond to the point light source one-to-one. Moreover, the reflective element may be combined by a plurality of reflective sheets or reflectors having a relatively small area, as long as the reflective elements combined with the plurality of reflective sheets or reflectors can form a plurality of reflective curved surfaces corresponding to the plurality of point sources. In addition, according to the distance between the point source and the reflective curved surface 3111, the curvature and shape of the reflective curved surface 3111 can be appropriately adjusted.

It can be understood that the point light source 35 can also be a non-side light point source, and the point source 35 can also be fixed between the bottom plate 311 and the light incident surface 373 of the optical plate 37 by other fixing structures. For example, the non-side-light point source is fixed to the fixed frame of the mesh structure and the non-side-light point source is directed toward the bottom plate. Thus, the light emitted by the non-side-light point source is substantially directly incident on the reflective surface 3111. The reflective curved surface 3111 is adjusted and then incident on the optical plate 37, and the light emitted from the light source 35 can be prevented from directly hitting the optical plate 37 to form a light spot having a strong light intensity.

It can be understood that a plurality of dots or pits can also be set on the light entrance surface of the optical plate. The light that is projected onto the light incident surface of the optical plate is further scattered to further improve the light uniformity of the backlight module. Similarly, diffusing particles may be added to the transparent resin material for preparing the optical plate to further increase the light uniformity of the backlight module.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

(this invention)

30‧‧‧Backlight module

31‧‧‧Frame

311‧‧‧floor

3111‧‧‧Reflective surface

313‧‧‧ side wall

33‧‧‧Flexible circuit board

35‧‧‧ point light source

37‧‧‧Optical board

371‧‧‧Glossy

373‧‧‧Into the glossy side

1 is a schematic cross-sectional view of a backlight module.

2 is a perspective exploded view of a preferred embodiment of a backlight module of the present invention.

3 is a schematic cross-sectional view of the backlight module shown in FIG. 2 after assembly.

30‧‧‧Backlight module

31‧‧‧Frame

311‧‧‧floor

3111‧‧‧Reflective surface

313‧‧‧ side wall

33‧‧‧Flexible circuit board

35‧‧‧ point light source

37‧‧‧Optical board

371‧‧‧Glossy

373‧‧‧Into the glossy side

Claims (10)

A direct type backlight module includes an optical plate, a plurality of point light sources, and a reflective component, the optical plate includes a light emitting surface and a light incident surface opposite to the light emitting surface, wherein the plurality of point light sources are disposed on the reflective component The improvement between the light-incident surface of the optical plate is that the direct-type backlight module comprises a plurality of flexible strips, and the plurality of flexible circuit boards are attached to the light-incident surface of the optical plate, and the plurality of point light sources are disposed. At the edge of the flexible circuit board, the complex point source directly faces the reflective element, and the reflective element is formed with a plurality of reflective curved surfaces corresponding to the point source. The direct type backlight module of claim 1, wherein each of the reflective curved surfaces is a spherical concave surface, and each of the point light sources corresponds to a center of the spherical concave surface. The direct type backlight module of claim 1, wherein the direct type backlight module comprises a frame, the frame comprises a bottom plate and a plurality of side walls extending from the edge of the bottom plate to the same side, the bottom plate is the reflection The component is disposed on the top of the sidewall. The direct type backlight module of claim 3, wherein the bottom plate and the side wall are integrally formed as a whole. The direct type backlight module of claim 1, wherein the flexible circuit board has a width of less than 5 mm. The direct type backlight module of claim 1, wherein the light incident surface of the optical plate has a plurality of dots. The direct type backlight module of claim 1, wherein the light incident surface of the optical plate is formed with a plurality of pits. The direct type backlight module of claim 1, wherein the light is The board is made of transparent resin. The direct type backlight module of claim 8, wherein the transparent resin is doped with diffusion particles. The direct type backlight module of claim 1, wherein the reflective element is composed of a plurality of reflective sheets or reflectors.