TW201405220A - Backlight module and display device using same - Google Patents

Abstract

The present invention relates to a backlight module and a display device using the backlight module. The backlight module includes a first reflecting structure, a point light source, and a light guide plate. The light guide plate includes an emitting surface, a bottom surface, a first side surface, a second side surface, and a third side surface. The emitting surface is oppose to the bottom surface. The first reflecting structure is configured to reflect rays from the point light source to the light guide plate. The first side surface, the second side surface, and the third side surface are positioned between the emitting surface and the bottom surface. The backlight module further includes a second reflecting structure. An end of the third side surface is connected to the first side surface, and the other end is connected to the second side surface. A plane included angle between the third side surface and the first side surface is an acute angle. A plane included angle between the third side surface and the second side surface is an obtuse angle. The second reflecting structure is positioned on a side of the third side surface. The point light source is positioned on an end of the first side surface adjacent to the third side surface.

Description

Backlight module and display device having the same

The invention relates to a backlight module and a display device having the same.

At present, a display device, such as a liquid crystal display device, generally uses a one-side light-emitting backlight module to provide a desired light source for the display of the display panel of the display device. The side-lit backlight module generally includes a light guide plate and a plurality of light emitting diode (LED) light sources. The light guide plate includes a light incident surface, a reflective bottom surface and a light exit surface. The plurality of LEDs are disposed adjacent to the light incident surface. The light emitted by the plurality of LEDs is transmitted in the light guide plate and finally emitted from the light exiting surface, thereby providing planar light having uniform gray scale for the display panel.

However, the use of the plurality of LEDs as a light source makes the backlight module and the display device having the backlight module more expensive to manufacture.

In view of this, it is necessary to provide a backlight module with a lower manufacturing cost.

In view of this, it is also necessary to provide a display device which is less expensive to manufacture.

The invention provides a backlight module, which comprises a first reflective structure, a point light source and a light guide plate. The light guide plate includes a light emitting surface, a bottom surface, a first side surface, a second side surface, and a third side surface. The light emitting surface is disposed opposite to the bottom surface. The first reflective structure is adjacent to and corresponding to the bottom surface, and the light for directing the point light source to the bottom surface is reflected back to the light guide plate. The first side surface, the second side surface, and the third side surface are located between the light emitting surface and the bottom surface. The backlight module further includes a second reflective structure. One end of the third side is connected to the first side, the other end is connected to the second side, and an angle between the third side and the first side is an acute angle, and between the third side and the second side The angle is an obtuse angle. The second reflective structure is disposed on a side of the third side, and the point light source is disposed at an end of the first side adjacent to the third side.

The present invention provides a display device including a first reflective structure, a point light source, and a light guide plate. The light guide plate includes a light emitting surface, a bottom surface, a first side surface, a second side surface, and a third side surface. The light emitting surface is disposed opposite to the bottom surface. The first reflective structure is adjacent to and corresponding to the bottom surface, and the light for directing the point light source to the bottom surface is reflected back to the light guide plate. The first side surface, the second side surface, and the third side surface are located between the light emitting surface and the bottom surface. The backlight module further includes a second reflective structure. One end of the third side is connected to the first side, the other end is connected to the second side, and an angle between the third side and the first side is an acute angle, and between the third side and the second side The angle is an obtuse angle. The second reflective structure is disposed on a side of the third side, and the point light source is disposed at an end of the first side adjacent to the third side. The point light source is disposed at an end of the first side adjacent to the third side.

Compared with the prior art, since the angle between the third side surface and the first side surface of the light guide plate of the backlight module of the present invention is an acute angle, the angle between the third side surface and the second side surface is an obtuse angle, and the second The reflective structure is disposed adjacent to the third side. Therefore, a portion of the light emitted by the point source disposed at an end of the first side adjacent to the third side is directed toward the third side, so that the light is reflected by the second reflective structure. The point source is converted into a surface source, thereby saving the number of point sources. Therefore, the manufacturing cost of the backlight module is correspondingly reduced.

1 and FIG. 2, FIG. 1 is a schematic top view of a backlight module according to a preferred embodiment of the present invention, and FIG. 2 is a cross-sectional structural view of the backlight module of FIG. 1 taken along II-II. The backlight module 10 includes a back plate 11 , a point light source 12 , a first reflective structure 13 , a second reflective structure 14 , and a light guide plate 16 . The back plate 11 is configured to receive the point light source 12, the first reflective structure 13, the second reflective structure 14, and the light guide plate 16. The first reflective structure 13 is located between the back plate 11 and the light guide plate 16 for reflecting the light emitted from the light guide plate 16 back into the light guide plate 16 . The light guide plate 16 is used to homogenize the light emitted by the point source 12 to provide plane light with uniform gray scale. Preferably, the point light source 12 is a Light Emitting Diode (LED) and the number is one.

Please refer to FIG. 3 together. FIG. 3 is a schematic perspective view of the light guide plate 16 . The light guide plate 16 includes a light emitting surface 161 , a bottom surface 162 , a first side surface 163 , a second side surface 164 , a third side surface 165 , and a fourth side surface 166 . The light exit surface 161 and the bottom surface 162 are opposite to each other. The first side surface 163 , the second side surface 164 , the third side surface 165 , and the fourth side surface 166 are located between the light emitting surface 161 and the bottom surface 162 . One end of the third side 165 is connected to the first side 163, the other end is connected to the second side 164, and an angle between the third side 165 and the first side 163 is an acute angle, and the third side 165 is The angle of the second side 164 is an obtuse angle. One end of the fourth side 166 is connected to the first side 163 , and the other end of the fourth side 166 is connected to the second side 164 . Preferably, the first side 163 is disposed in parallel with the second side 164, the fourth side 166 is perpendicular to the first side 163 and the second side 164, and between the third side 165 and the first side 163 The included angle is an acute angle greater than 45 degrees. After measurement, the optimum angle range is: 65 degrees or more and 80 degrees or less. The second reflective structure 14 is disposed on a side of the third side 165.

The first reflective structure 13 is adjacent and corresponding to the bottom surface 162. Preferably, the second reflective structure 14 is a reflective film, and the reflective film is attached to the third side 165. The point source 12 is disposed at an end of the first side 163 adjacent to the third side 165. Further, the light guide plate 16 is further disposed with a mesh point adjacent to the inside of the bottom surface 162 for scattering light.

Specifically, a projection area defining the third side surface 165 on the first side surface 163 is a light source setting area, and the point light source 12 is disposed corresponding to the light source setting area. Preferably, the point source 12 is completely disposed corresponding to the light source setting area.

Please refer to FIG. 4. FIG. 4 is a schematic diagram of the optical path of the light line of the point source 12. First, the light emitted by the point source 12 is incident on the inside of the light guide plate 16 through the first side 163, wherein most of the light is directed toward the third side 165, and a small portion of the light is directed to other places of the light guide plate 16. . The majority of the light that is directed toward the third side surface 165 is reflected by the second reflective structure 14 and returned to the light guide plate 16 , and the portion is directly emitted from the light exit surface 161 . Then, the light that is reflected by the second reflective structure 14 and returned to the inside of the light guide plate 16 and the small portion of the light that is directed to the other portion of the light guide plate 16 and then the scattering of the dots inside the light guide plate 16 and the first reflection The reflection or the like of the structure 13 is emitted from the light-emitting surface 161.

Compared with the prior art, the angle between the third side 165 and the first side 163 of the light guide plate 16 of the backlight module 10 of the present invention is an acute angle, and the angle between the third side 165 and the second side 164 is An obtuse angle, and the second reflective structure 14 is disposed adjacent to the third side 165. Therefore, most of the light emitted by the point source 12 disposed at an end of the first side 163 adjacent to the third side 165 is directed toward the third side. 165, so that the light is reflected by the second reflective structure 14 to convert the point light source 12 into a surface light source, thereby saving the number of the point light sources 12. Therefore, the manufacturing cost of the backlight module 10 is correspondingly reduced.

Please refer to FIG. 5. FIG. 5 is a schematic structural view of a display device according to a preferred embodiment of the present invention. The display device 1 includes the backlight module 10 and the display panel 20. The backlight module 10 is stacked on the display panel 20, wherein the display panel 20 is used to display a screen. The backlight module 10 is configured to provide the required planar light for the display of the display panel 20.

The present invention is not limited to the above embodiments. For example, the number of the point light sources 12 may vary according to the size of the backlight module 10. When the size of the backlight module 10 is large, the number of the point light sources 12 may also be two or three, etc., and are disposed at one end of the first side surface 163 adjacent to the third side surface 165.

The outer contour of the back plate 11 may be rectangular in shape except for the shape of the light guide plate 16 shown in FIG. Correspondingly, the shape of the second reflective structure 14 can also cooperate with the shape of the light guide plate 16 such that the cross section of the two is a rectangle. For example, when the cross section of the light guide plate 16 is a right-angled trapezoid, the cross-section of the second reflective structure 14 is a right-angled triangle of a corresponding shape.

When the back plate 11 has a function of reflecting light, the back plate 11 is reflected to the third side 165 or/and by adjusting the shape of the back plate 11 and the combination relationship with the light guide plate 16. The light of the bottom surface 162, and thus the second reflective structure 14 or/and the first reflective structure 13 may be omitted. The thickness of the backlight module 10 is further reduced and the weight of the backlight module 10 is reduced. In addition, the first reflective structure 13 or/and the second reflective structure 14 may also be integrally formed with the back plate 11.

An angle between the fourth side 166 and the first side 163 is an acute angle, and an angle between the fourth side 166 and the second side 164 is an obtuse angle. Correspondingly, the point source 12 can also be disposed correspondingly to the end of the first side 163 adjacent to the fourth side 166.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

1. . . Display device

10. . . Backlight module

20. . . Display panel

11. . . Backplane

12. . . point Light

13. . . First reflective structure

14. . . Second reflective structure

16. . . Light guide

161. . . Glossy surface

162. . . Bottom

163. . . First side

164. . . Second side

165. . . Third side

166. . . Fourth side

1 is a top plan view of a preferred embodiment of a backlight module of the present invention.

2 is a schematic cross-sectional view of the backlight module of FIG. 1 taken along II-II.

3 is a schematic perspective view of a light guide plate of the backlight module shown in FIG. 1 .

4 is a schematic view showing an optical path of a light-emitting line of a point light source of the backlight module shown in FIG. 1.

FIG. 5 is a schematic structural view of a display device according to a preferred embodiment of the present invention.

10. . . Backlight module

11. . . Backplane

12. . . point Light

14. . . Second reflective structure

16. . . Light guide

Claims (10)

A backlight module includes a first reflective structure, a point light source, and a light guide plate. The light guide plate includes a light emitting surface, a bottom surface, a first side surface, a second side surface, and a third side surface. The light emitting surface is opposite to the bottom surface. a reflective structure is disposed adjacent to and corresponding to the bottom surface, and light for directing the point light source to the bottom surface is reflected back to the light guide plate, the first side surface, the second side surface and the third side surface being located between the light emitting surface and the bottom surface The backlight module further includes a second reflective structure, one end of the third side is connected to the first side, the other end is connected to the second side, and the third side is between the first side and the first side An angle is an acute angle, an angle between the third side and the second side is an obtuse angle, and the second reflective structure is disposed on a side of the third side, the point light source is disposed on the first side adjacent to the third side One end. The backlight module of claim 1, wherein the projection area defining the third side on the first side is a light source setting area, and the point light source is disposed corresponding to the light source setting area. The backlight module of claim 2, wherein the point light source is completely disposed corresponding to the light source setting area. The backlight module of claim 2, wherein the light emitted by the point source is incident on the light guide plate from the first side, wherein the light incident on the third side is reflected by the second reflective structure Part of the return to the light guide plate, and some of the light is directly emitted from the light exit surface. The backlight module of claim 2, wherein the first side surface is disposed in parallel with the second side surface. The backlight module of claim 5, wherein the light guide plate further includes a fourth side between the light emitting surface and the bottom surface, and one end of the fourth side is connected to the first side, The other end of the fourth side is connected to the second side. The backlight module of claim 6, wherein the fourth side is perpendicular to the one side and the second side. The backlight module of claim 7, wherein the angle between the third side and the first side is 65 degrees or more and less than 80 degrees. The backlight module of claim 2, wherein the second reflective structure is a reflective film, and the reflective film is attached to the third side. A display device comprising a display panel and a backlight module for providing a light source for the display panel, wherein the backlight module is the backlight module according to any one of the preceding claims.