TWI472849B - Backlight module - Google Patents

Description

Backlight module

The present invention relates to a backlight module, and more particularly to a backlight module having a reflective sheet.

At present, electronic devices often use a flat display module to display images, and the technology of the liquid crystal display module is more sophisticated and popular. However, since the display panel of the liquid crystal display module itself cannot emit light, a backlight module is provided under the display panel to provide light required for displaying the screen.

Generally, a side-edge backlight module includes a light source and a light guide plate. The main function of the light guide plate is to generate a uniform surface light source through a medium conduction and energy divergence mechanism and a modulation mode. In addition, a reflective sheet may be disposed on the back surface and the side surface of the light guide plate, so that the light emitted from the light guide plate on the back surface and the side surface is reflected by the reflection sheet back into the light guide plate and emitted from the light exit surface to improve the light utilization rate. Gluing the reflective sheet to the side of the light guide plate by the adhesive layer is a common fixing method. However, due to the uneven structure of the inner layer of the adhesive layer, the light passing through the adhesive layer is scattered, which causes the light guide plate to appear bright and halo, affecting the backlight. The light output of the module.

The Republic of China Patent No. TW I295399 discloses a backlight module in which a side surface of a light guide plate is attached with a double-sided tape to enhance the light use efficiency. The Republic of China Patent No. TW 201035641 discloses that a plurality of reflective sheets are included between the light guide plate and the plurality of light sources, and the reflective sheets are staggered with the light sources. The Republic of China Patent No. TW 201111879 discloses a backlight module The plurality of first adhesive materials are disposed between the reflective sheet and the light guide sheet, and adhere the reflective sheet, the light guide sheet, and the light emitting element.

The invention provides a backlight module with better light-emitting effect.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein.

In an embodiment of the present invention, a backlight module includes a light guide plate, a glue layer, a first reflection sheet, and at least one light source. The light guide plate has a light emitting surface, a back surface, a first side surface and a second side surface. The light exit surface is opposite to the back side. The first side surface and the second side surface are respectively connected between the light emitting surface and the back surface. The glue layer is glued to the first side. The area of the first side covered by the glue layer is less than three quarters of the total area of the first side. The first reflective sheet has a reflective surface. The reflective surface is glued to the adhesive layer to fix the first reflective sheet to the first side. The light source is disposed on the second side.

Based on the above, in the above embodiment of the present invention, since the area of the area covered by the glue layer on the first side is smaller than three quarters of the total area of the first side, the light entering the light guide plate through the glue layer can be reduced. The probability of the light guide plate is improved, thereby improving the light-emitting effect of the backlight module.

The above described features and advantages of the invention will be apparent from the following description.

The foregoing and other objects, features, and advantages of the invention will be apparent from the Detailed Description The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only directions referring to the additional schema. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

FIG. 1 is a perspective view of a backlight module according to an embodiment of the invention. 2 is a partial cross-sectional view of the backlight module of FIG. 1. 3 is a schematic view of the first reflective sheet and the adhesive layer of FIG. 1. Referring to FIG. 1 to FIG. 3 , the backlight module 100 of the present embodiment includes a light guide plate 110 , a glue layer 120 , a first reflection sheet 130 , and at least one light source 140 (shown as a plurality). The light guide plate 110 has a light emitting surface 112, a back surface 114, a first side surface 116 and a second side surface 118. The light-emitting surface 112 is opposite to the back surface 114, and the first side surface 116 and the second side surface 118 are connected between the light-emitting surface 112 and the back surface 114, respectively. The adhesive layer 120 is glued to the first side 116 , and the reflective surface 132 of the first reflective sheet 130 is glued to the adhesive layer 120 to fix the first reflective sheet 130 to the first side 116 . The light sources 140 are disposed on the second side 118 and are adapted to emit light to the light guide plate 110.

In the present embodiment, the area of the region 116a of the first side 116 of the light guide plate 110 covered by the glue layer 120 is smaller than three quarters of the total area of the first side surface 116. Thereby, the probability that the light of the light source 140 entering the light guide plate 110 passes through the adhesive layer 120 can be reduced, thereby improving the bright halo phenomenon of the light guide plate 110 and improving the light output effect of the backlight module 100.

In this embodiment, the area of the region 116a of the first side 116 of the light guide plate 110 covered by the glue layer 120 is about three points of the total area of the first side surface 116. Secondly, the present invention is not limited thereto. In other embodiments, the area of the region 116a of the first side 116 of the light guide plate 110 covered by the glue layer 120 may be less than four quarters of the total area of the first side 116. The other appropriate size of three. For example, under the premise that the first reflective sheet 130 can be firmly glued to the first side 116 of the light guide plate 110, the size of the adhesive layer 120 can be reduced, and the region 116a of the first side 116 covered by the adhesive layer 120 can be The area is reduced to one of two or less of the total area of the first side 116 to further improve the brightness of the light guide plate 110.

The backlight module 100 of the present embodiment is, for example, a flat display module for an electronic device. However, the present invention is not limited thereto. In other embodiments, the backlight module 100 can be used for other suitable devices.

4 is a partial cross-sectional view of a conventional backlight module. FIG. 5 is a comparison diagram of the bright halo phenomenon of the backlight module of FIG. 2 and the bright halo phenomenon of the backlight module of FIG. 4. The horizontal axis in FIG. 5 is the displacement in the direction D with the first side surface 116/216 of the light guide plate 110/210 as a reference point, and the vertical axis is the intensity of the bright halo phenomenon. In the arrangement of the backlight module 100 of FIG. 2, the intensity of the bright halo phenomenon formed by the light of the glue layer 120 on the light guide plate 110 changes along the direction D as shown by the solid line L1 of FIG.

In the backlight module 200 of FIG. 4, the first reflective sheet 230 is glued to the light guide plate 210 by the adhesive layer 220. The area 216a of the first side 216 of the light guide plate 210 covered by the adhesive layer 220 is about the first side. 90% of the total area of 216. In this case, the change in the intensity of the bright halo phenomenon formed by the light of the glue layer 220 on the light guide plate 210 in the direction D is as shown by the broken line L2 of FIG. Comparing the solid line L1 and the broken line L2 in Fig. 5, it can be seen that the horizontal axis is In the range of 0 to d, the brightness of the light guide plate 210 of the conventional backlight module 200 is more serious, and the backlight module 100 of the present embodiment improves the brightness of the light guide plate 110 by reducing the distribution area of the adhesive layer 120. phenomenon.

Referring to FIG. 1 , in addition to the first reflective sheet 130 , the backlight module 100 of the present embodiment further includes a first reflective sheet 130 ′ and a first reflective sheet 130 ′′ on the other side of the light guide plate 110 . The arrangement of the reflective sheet 130 ′ and the first reflective sheet 130 ′′ is similar to that of the first reflective sheet 130 , and details are not described herein again. In addition, as shown in FIG. 1 and FIG. 2 , the backlight module 100 further includes a second reflective sheet 150 disposed on the back surface 114 of the light guide plate 110 for reflecting the light emitted by the light sources 140 .

In this embodiment, the light source 140 is, for example, a light emitting diode (LED) light source. However, the invention is not limited thereto. In other embodiments, the cold cathode fluorescent tube (cold cathode) may also be used. Fluorescent lamp, CCFL) replaced. The material of the glue layer 120 includes a transparent material such that light emitted by the light source 140 can pass through the glue layer 120.

In the present embodiment, the total area of the reflective surface 132 of the first reflective sheet 130 is equal to or slightly smaller than the total area of the first side 116 of the light guide plate 110. Therefore, in the case where the area of the region 132a of the reflective surface 132 covered by the adhesive layer 120 is smaller than three quarters of the total area of the reflective surface 132, the area of the region 116a of the first side surface 116 covered by the adhesive layer 120 is also smaller than that of the first surface 116. Three-quarters of the total area of one side 116. In the process of bonding the first reflective sheet 130 to the light guide plate 110, the appropriately sized adhesive layer 120 may be glued to the reflective surface 132 of the first reflective sheet 130 to cover the reflective surface 132 covered by the adhesive layer 120. The area of 132a is less than three quarters of the total area of the reflective surface 132, and then the glue layer 120 on the first reflective sheet 130 is glued to the first side 116 of the light guide plate 110.

Referring to FIG. 2 and FIG. 3 , in the embodiment, the reflective surface 132 of the first reflective sheet 130 has opposite side edges 132 b and one side 132 c , and the side edges 132 b and the side edges 132 c are respectively located on the light guide plate 110 . The light emitting surface 112 and the back surface 114 of the light guide plate 110. The distance between the glue layer 120 and the side edge 132c is greater than the distance between the glue layer 120 and the side edge 132b, so that the glue layer 120 is located closer to the side edge 132b, and at most three-quarters of the reflection surface 132 is glued. Layer 120 is covered. The present invention does not limit the distribution position and shape of the adhesive layer 120, and the following is exemplified by the drawings.

6A is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention. Referring to FIG. 6A, the first reflective sheet 330 of the present embodiment has a reflective surface 332 having opposite side edges 332b and one side edge 332c. The distance between the glue layer 320 and the side edge 332c is smaller than the distance between the glue layer 320 and the side edge 332b, so that the glue layer 320 is located closer to the side edge 332c, and at most three-quarters of the reflection surface 332 is glued. Layer 320 is covered.

6B is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention. Referring to FIG. 6B, the first reflective sheet 430 of the present embodiment has a reflective surface 432 having opposite side edges 432b and one side 432c. The distance between the glue layer 420 and the side edge 432c is equal to the distance between the glue layer 420 and the side edge 432b, so that the glue layer 420 is located at the middle of the reflection surface 432, and at most three-quarters of the reflection surface 432 is glued. 420 coverage.

6C is a view showing a first reflective sheet and a rubber layer according to another embodiment of the present invention; intention. Referring to FIG. 6C, the first reflective sheet 530 of the embodiment has a reflective surface 532. The glue layer 520 includes a plurality of sections that are glued to the reflective surface 532 and spaced apart, and up to three-quarters of the reflective surface 532 is covered by the glue layer 520.

6D is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention. Referring to FIG. 6D, the first reflective sheet 630 of the embodiment has a reflective surface 632. The glue layer 620 includes a plurality of sections that are glued to the reflective surface 632 and spaced apart. The area of each section of the glue layer 620 is smaller than the area of each section of the glue layer 520 of FIG. 6C, so that more areas of the reflection surface 632 are exposed, thereby reducing the probability of light passing through the glue layer 620, thereby improving the light guide plate. Bright and dim phenomenon, improve the light output effect of the backlight module.

In summary, in the above embodiment of the present invention, since the area of the area covered by the glue layer on the first side is smaller than three quarters of the total area of the first side, the light passing through the light guide plate can be reduced. The probability of the glue layer, thereby improving the brightness of the light guide plate and improving the light output effect of the backlight module.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention. In addition, the terms “first”, “second” and the like mentioned in the specification or the scope of the claims are only used to name the elements or distinguish different embodiments or ranges. It is not intended to limit the upper or lower limit on the number of components.

100‧‧‧Backlight module

110, 210‧‧‧Light guide plate

112‧‧‧Glossy

114‧‧‧Back

116, 216‧‧‧ first side

116a, 132a, 216a‧‧‧ areas

118‧‧‧ second side

120, 220‧‧ ‧ adhesive layer

130, 130', 130", 230, 330, 430, 530, 630‧‧‧ first reflection sheet

132, 332, 432, 532, 632‧‧ ‧ reflective surface

132b, 132c, 332b, 332c, 432b, 432c‧‧‧ side

140‧‧‧Light source

150‧‧‧second reflection sheet

D‧‧‧ Direction

L1‧‧‧ solid line

L2‧‧‧ dotted line

FIG. 1 is a perspective view of a backlight module according to an embodiment of the invention.

2 is a partial cross-sectional view of the backlight module of FIG. 1.

3 is a schematic view of the first reflective sheet and the adhesive layer of FIG. 1.

4 is a partial cross-sectional view of a conventional backlight module.

FIG. 5 is a comparison diagram of the bright halo phenomenon of the backlight module of FIG. 2 and the bright halo phenomenon of the backlight module of FIG. 4.

6A is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention.

6B is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention.

6C is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention.

6D is a schematic view of a first reflective sheet and a glue layer according to another embodiment of the present invention.

100‧‧‧Backlight module

110‧‧‧Light guide plate

112‧‧‧Glossy

114‧‧‧Back

116‧‧‧ first side

116a, 132a‧‧‧ Area

120‧‧ ‧ glue layer

130‧‧‧First reflection sheet

132‧‧‧reflecting surface

132b, 132c‧‧‧ side

150‧‧‧second reflection sheet

D‧‧‧ Direction

Claims (8)

A backlight module includes: a light guide plate having a light emitting surface, a back surface, a first side surface, and a second side surface, wherein the light emitting surface is opposite to the back surface, and the first side surface and the second side surface are respectively connected to the light emitting surface Between the light-emitting surface and the back surface; a glue layer glued to the first side, wherein an area of the first side covered by the glue layer is smaller than three-quarters of a total area of the first side; The reflective sheet has a reflective surface, wherein the reflective surface is glued to the adhesive layer to fix the first reflective sheet to the first side surface; and at least one light source is disposed on the second side surface. The backlight module of claim 1, wherein the total area of the reflective surface is equal to or smaller than a total area of the first side. The backlight module of claim 1, wherein an area of the reflective surface covered by the adhesive layer is less than three quarters of a total area of the reflective surface. The backlight module of claim 1, wherein the reflective surface has opposite side edges, and the two sides are respectively located on the light emitting surface and the back surface, between the glue layer and a side edge. The distance is equal to the distance between the glue layer and the other side. The backlight module of claim 1, wherein the reflective surface has opposite side edges, and the two sides are respectively located on the light emitting surface and the back surface, between the glue layer and a side edge. The distance is greater than the distance between the glue layer and the other side. The backlight module of claim 1, wherein the adhesive layer comprises a plurality of segments, the segments being spaced apart. The backlight module of claim 1, wherein the material of the adhesive layer comprises a transparent material. The backlight module of claim 1, further comprising a second reflective sheet disposed on the back surface.