TWI485478B - Backlight module having reflective layer and display apparatus thereof - Google Patents

Description

Backlight module with reflective layer and display device thereof

The present invention relates to a backlight module and a display device therewith; in particular, the present invention relates to a backlight module having a reflective layer and a display device therewith.

Portable electronic devices such as notebook computers, mobile phones, tablet computers, etc., have been widely used in daily life. With the development of technology, the size of the portable electronic device must meet the characteristics of light, thin, short, and small, so as to achieve the purpose of portability. However, because of the spatial variation caused by the thinning process, in addition to the need to sacrifice some of the components in order to reduce the space required to accommodate, it also faces the challenge of display effect and structural stability.

1A and 1B are schematic views of a conventional display device. As shown in FIG. 1A, the back plate 32 of the conventional display device 10 is surrounded by the outer side and has a hollow design, and the portion of the back plate 32 extending toward the center has a height difference from the outer portion. Referring to FIG. 1B , a cross-sectional view of a conventional display device 10 is shown in FIG. 1B . The conventional display device 10 mainly includes a display panel 20 and a backlight module 30 . In the current assembly of the display device, a recess 33 must be reserved at the bottom of the backing plate 32 for the positioning tape 40 to be attached. However, such a design may cause the back plate 32 to face the surface of the light guide plate 31 with a height difference. As shown in FIG. 1B, the position of the interlayer space 34 is the gap generated after the recessed portion 33 is formed (corresponding to the back plate 32 of FIG. 1A). As a result of the centrally extending portion, the light-emitting effect of the display area B corresponding to the interlayer space 34 is affected. In addition, the thinned reflective film 35 causes an increase in light transmittance, thereby reducing the reflection effect of the reflective film 35, and in addition to the aforementioned structure, the brightness of the edge of the display area B is significantly darkened and reduced. The willingness of the purchaser.

One of the objectives of the present invention is to provide a composite reflective layer in a backlight module to improve the optical performance of the backlight module and the display device.

Another object of the present invention is to support the light guide plate with a reflective layer to enhance the structural support effect.

The backlight module includes a light guide plate, a back plate and a reflective layer. The back plate portion is disposed corresponding to the bottom surface of the light guide plate; further, the back plate has an outer ring portion parallel to the bottom surface of the light guide plate and an inner ring portion extending from the outer ring portion toward the center of the light guide plate, and the outer ring portion supports the bottom surface of the light guide plate edge. The outer ring portion supports a part of the light guide plate, and a sandwich space is sandwiched between the inner ring portion and the bottom surface. A reflective layer is disposed in the interlayer space on one side of the inner ring portion facing the bottom surface of the light guide plate and filled with at least a portion of the interlayer space.

In addition to the backlight module, the display device also includes a display panel disposed on the backlight module, such as a side of the light guide plate facing away from the bottom surface. By the arrangement of the reflective layer, the optical performance of the edge of the display area of the display panel can be improved, and the uniformity of brightness is increased.

The invention provides a backlight module and a display device therewith. The backlight module preferably includes an edge-lit light source structure; however, in different embodiments, a direct-lit light source structure may also be included. The display device is preferably a liquid crystal display; however, in various embodiments, other displays using the backlight module may be used.

2A is a schematic diagram of an embodiment of a display device 100 of the present invention. As shown in FIG. 2A, the display device 100 has a display panel 200 and a backlight module 300. Backlight module 300 There are mainly a light guide plate 310, a back plate 320 and a reflective layer 340. The back plate 320 is disposed at the bottom of the display device 100 and covers the display device 100 from the outside. In addition, the back plate 320 has an outer ring portion 322 parallel to the bottom surface of the light guide plate 310 and an inner ring portion 324 extending from the outer ring portion 322 toward the center of the light guide plate 310, and the outer ring portion 322 supports the edge of the bottom surface 312 of the light guide plate 310. In a preferred embodiment, the backing plate 320 is made of sheet metal, and the inner ring portion 324 can be formed by stamping; however, in different embodiments, the backing plate 320 can be made of other different materials or injection molding. Made in different ways. As shown in FIG. 2A, the outer ring portion 322 supports a portion of the light guide plate 310, particularly the edge portion, and the sandwich space 330 is sandwiched between the inner ring portion 324 and the bottom surface 312. The reflective layer 340 is at least partially filled in the interlayer space 330. In the embodiment shown in FIG. 2A, the reflective layer 340 is disposed on the inner ring portion 324 facing one surface of the bottom surface 312 of the light guide plate 310 and filling the sandwich space 330. The light guide plate 310 is supported.

In addition, the display panel 200 is disposed on one side of the light guide plate 310 facing away from the bottom surface 312 , that is, the display panel 200 and the outer ring portion 322 are disposed on opposite sides of the light guide plate 310 . The edge of the display area B of the display panel 200 is the position corresponding to the inner ring portion 324. In detail, the projection range of the inner ring portion 324 on the display panel 200 is located at the edge of the display area B. The portion of the display area B toward the center of the light guide plate 310 does not correspond to the back plate 320, or the hollow area C corresponding to the back plate 320. Please also refer to Figure 2B. 2B is a schematic view showing the positional relationship between the back plate 320 and the reflective layer 340 of the present invention. As shown in Fig. 2B, a cross-sectional view as shown in Fig. 2A is obtained along the AA' direction of Fig. 2B. The back plate 320 is located outside the display device 100 and the reflective layer 340 is located inside the display device 100 and covers the inner ring portion (not shown). The inner ring portion and the reflective layer 340 surround the hollow region C.

In the preferred embodiment, the bottom surface 312 of the light guide plate 310 is formed with a plurality of microstructures 314, and the distribution density of the microstructure 314 of the hollow region C on the bottom surface 312 is preferably larger than the projection range of the inner ring portion 324 on the bottom surface 312. The microstructure 314 is distributed in density. As shown in FIG. 2A, the bottom surface 312 of the light guide plate 310 corresponds to a portion of the inner ring portion 324. The microstructure 314 is disposed at a lower density; the bottom surface 312 of the light guide plate 310 corresponds to a portion of the hollow region C, and the microstructure 314 is densely disposed. In other words, the regions in which the microstructures 314 are disposed sparsely are preferably annularly distributed. By this arrangement, the amount of light emitted from the hollow region C can be increased and the display device 100 can be kept light in weight, and can be matched with the arrangement or material of the reflective layer 340 to obtain the most uniform light-emitting effect.

As shown in FIG. 2A, the backing plate 320 includes a side wall 326 that is coupled to the outer ring portion 322, that is, the side wall 326 is connected to the opposite side of the outer ring portion 322 with respect to the inner ring portion 324 and surrounds the outer side of the display device 100. A positioning tape 400 is attached to the outer surface of the side wall 326. As shown in FIG. 2A, the two sides of the positioning tape 400 protrude from the side wall 326 respectively, and one side of the positioning tape 400 is bent and connected to the surface of the backlight module 300, that is, the outer surface 202 of the display panel, and the other side is bent and connected to the outer ring. Outside surface 323. As shown in FIG. 2A, the cross section of the positioning tape 400 is such as the outer edge of the C-shaped cover display panel 200, the side wall 326 of the back plate 320, and the outer surface 323 of the outer ring portion 322. The outer surface of the inner ring portion 324 protrudes from the inner surface of the outer ring portion 322 to form a recess portion 321 outside the outer ring portion 322, so that the portion of the positioning tape 400 connected to the outer surface of the outer ring portion 322 can be accommodated in the recess portion 321, so After the positioning tape 400 is attached to the bottom of the back plate 320, the flatness of the display device 100 can be maintained to facilitate assembly.

In addition, the light guide plate 310 further has a reflective film 350 on the bottom surface 312, and the outer ring portion 322 supports the reflective film 350 to indirectly support the bottom surface 312. As shown in FIG. 2A, the top surface 342 of the reflective layer 340 between the reflective film 350 and the inner ring portion 324 is flush with the surface of the bottom surface 312 of the outer ring portion 322 supporting the light guide plate 310. In this way, the reflective layer 340 can indirectly support the light guide plate 310 by supporting the reflective film 350 to improve the stability of the structure. In this embodiment, the light reflectance of the reflective layer 340 is the same as the light reflectance of the surface of the outer ring portion 322. On the other hand, in order to avoid the reflection effect of the thinned reflective film 350, the light reflectance of the reflective layer 340 is preferably greater than that of the reflective film 350, and/or the light of the reflective layer 340 is worn. The transmittance is smaller than the light of the reflective film 350 The transmittance, therefore, the light passing through the reflective film 350 can be reflected by the reflective layer 340 to improve the light extraction efficiency. At the same time, by means of the setting manner, the edge of the display area B, that is, the projection range corresponding to the inner ring portion 324, can be raised to avoid dark bands.

In other embodiments, improving the light-emitting effect at the edge of the display region B can also be achieved by using a reflective layer 340 having a high reflectivity while simultaneously adjusting the density of the microstructure 314. Another embodiment of the display device 100 is shown in FIG. It can be noted in FIG. 3 that the reflective film 350 can be further omitted in the display device 100 to increase the flexibility in space utilization. In this embodiment, the microstructures 314 in the light guide plate 310 are uniformly distributed. For example, in FIG. 3, the microstructures 314 are all adjusted to be dense, and in the interlayer space, the reflective layer 340 having high reflectivity is disposed. The light-emitting effect at the edge of the display area B is adjusted by the cooperation of the reflective layer 340 and the microstructure 314. Therefore, the reflective layer 340 can not only increase the structural support, but also improve the light-emitting effect. On the other hand, the adjustment of the distribution density of the reflective layer 340 and the microstructure 314 having high reflectivity can also remove one or all of the reflective film 350. Further, the space available inside the display device 100 is increased.

4 is a schematic diagram of another embodiment of a display device 100 of the present invention. The structure of the display device 100 shown in Fig. 4 is substantially as described above. The difference is that, in this embodiment, the distance between the top surface 342 of the reflective layer 340 and the bottom surface 312 of the light guide plate 310 is greater than the distance between the surface of the outer ring portion 322 and the bottom surface 312 of the light guide plate 310; in other words, as shown in FIG. In the cross section, the top surface of the reflective layer 340 is lower than the surface height of the outer ring portion 322. As shown in FIG. 4, the reflective layer 340 fills a portion of the sandwich space 330. In this embodiment, the light reflectance of the reflective layer 340 is greater than the light reflectance of the outer ring portion 322 surface. On the other hand, in order to avoid the reflection effect of the thinned reflective film 350, the light reflectance of the reflective layer 340 is preferably greater than that of the reflective film 350, and/or the light of the reflective layer 340 is worn. The transmittance is smaller than the light transmittance of the reflective film 350, whereby the brightness at the edge of the display area B can be improved by the arrangement.

The present invention has been described by the above-described related embodiments, but the above embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the invention. On the contrary, modifications and equivalents of the spirit and scope of the invention are included in the scope of the invention.

100‧‧‧ display device

200‧‧‧ display panel

202‧‧‧Display panel exterior surface

300‧‧‧Backlight module

310‧‧‧Light guide plate

312‧‧‧ bottom

314‧‧‧Microstructure

320‧‧‧ Backplane

321‧‧‧Depression

322‧‧‧Outer Rings

323‧‧‧Outer surface of the outer ring

324‧‧‧ Inner Ring Department

326‧‧‧ side wall

330‧‧‧Mezzanine space

340‧‧‧reflective layer

342‧‧‧ top surface

350‧‧‧Reflective film

400‧‧‧Positioning tape

B‧‧‧Display area

C‧‧‧ hollow area

1A and 1B are schematic views of a conventional display device; FIG. 2A is a schematic view showing a positional relationship between a back plate and a reflective layer according to the present invention; FIG. 3 is a schematic view showing another embodiment of the display device of the present invention; FIG. 4 is a schematic view of another embodiment of a display device of the present invention.

100‧‧‧ display device

200‧‧‧ display panel

202‧‧‧Display panel exterior surface

300‧‧‧Backlight module

310‧‧‧Light guide plate

312‧‧‧ bottom

314‧‧‧Microstructure

320‧‧‧ Backplane

321‧‧‧Depression

322‧‧‧Outer Rings

323‧‧‧Outer surface of the outer ring

324‧‧‧ Inner Ring Department

326‧‧‧ side wall

330‧‧‧Mezzanine space

340‧‧‧reflective layer

342‧‧‧ top surface

350‧‧‧Reflective film

400‧‧‧Positioning tape

B‧‧‧Display area

Claims (13)

A backlight module includes: a light guide plate having a bottom surface; a back plate supporting an edge of the bottom surface; wherein the back plate has an outer ring portion and an inner ring portion, the outer ring portion is parallel to the bottom surface And supporting the edge of the bottom surface; the inner ring portion extends from the outer ring portion toward the center of the light guide plate, and has a sandwich space between the bottom surface; and a reflective layer disposed on the inner ring portion facing the bottom surface And filling at least a portion of the interlayer space; and a reflective film disposed on the bottom surface, the outer ring portion supporting the reflective film to indirectly support the bottom surface; wherein the reflective layer is located in the reflective film and the inner ring Between the ministries. The backlight module of claim 1, wherein the inner ring portion and the reflective layer together form a hollow region. The backlight module of claim 2, wherein the bottom surface is formed with a plurality of microstructures, the microstructure distribution density of the hollow region on the bottom surface is larger than the projection range of the inner ring portion on the bottom surface Structure distribution density. The backlight module of claim 1, wherein a top surface of the reflective layer is flush with a surface of the outer ring portion supporting the bottom surface. The backlight module of claim 4, wherein the reflective layer has the same light reflectivity as the surface of the outer ring portion. The backlight module of claim 1, wherein a distance between a top surface of the reflective layer and the bottom surface is greater than a distance between a surface of the outer ring portion and the bottom surface; a light reflectance of the reflective layer is greater than a surface of the outer ring portion Light reflectivity. The backlight module of claim 1, wherein the reflective layer has a light reflectance greater than The light reflectance of the reflective film. The backlight module of claim 1, wherein the reflective layer has a light transmittance that is less than a light transmittance of the reflective film. The backlight module of claim 1, wherein the reflective layer indirectly supports the light guide plate by supporting the reflective film. A display device, comprising: a backlight module according to any one of claims 1 to 9; and a display panel disposed on a side of the light guide plate facing away from the bottom surface; wherein the display panel has a display The area, the projection range of the inner ring on the display panel is located at the edge of the display area. The display device of claim 10, wherein the back panel comprises a side wall connecting the opposite side of the outer ring portion with respect to the inner ring portion, the side wall surrounding the outer side of the display device. The display device of claim 11, further comprising a positioning tape attached to the outer surface of the side wall; wherein two sides of the positioning tape respectively protrude from the side wall, and one side is bent and connected to the display panel opposite to the backlight The outer surface of the module is bent to connect the outer surface of the outer ring portion. The display device of claim 12, wherein the outer surface of the inner ring portion protrudes from an inner surface of the outer ring portion to form a recessed portion outside the outer ring portion, the positioning tape connecting the outer surface of the outer ring portion A portion is housed in the recess.