CN102086992B - Backlight module and application thereof - Google Patents

Abstract

The present invention relates to a backlight module and its application. The backlight module at least comprises: a light guide plate having a light incident surface; a light emitting diode light source module arranged beside the light incident surface; and a reflector having an opening arranged adjacent to the light incident surface, wherein the light emitting diode light source module is arranged in the reflector and incidents light toward the light incident surface through the opening, and the height of the opening is less than the thickness of the light guide plate. The backlight module can effectively reduce the bright spot phenomenon.

Description

Backlight module and its application

technical field

The invention relates to a backlight module, and in particular to a backlight module capable of effectively alleviating the phenomenon of a hot spot (Hot Spot) and its application on a liquid crystal display (LCD).

Background technique

Please refer to FIG. 1A , which shows a partial cross-sectional view of a conventional backlight module. The backlight module 100 mainly includes a light guide plate 102, an LED light source module 106 and a reflector 116, wherein the LED light source module 106 is arranged on one side of the light guide plate 102, and the reflector 116 is surrounded by the outside of the LED light source module 106 and Together with the light guide plate 102 , it surrounds the LED light source module 106 . The reflector 116 is composed of three side panels 118 , 120 and 122 , wherein the side panels 118 and 120 are connected to opposite ends of the side panel 122 respectively, and the side panels 118 and 120 are opposite to each other. The LED light source module 106 mainly includes a circuit board 110 and several LEDs 108 , wherein the LEDs 108 are disposed on the surface of the circuit board 110 . In the LED light source module 106 , each LED 108 has a light emitting surface 112 . A side of the light guide plate 102 adjacent to the LED light source module 106 has a light incident surface 104 .

In the backlight module 100 , the LED light source module 106 is disposed in the space formed by the side plates 118 , 120 and 122 of the reflector 116 , and the circuit board 110 is attached on the side plate 118 of the reflector 116 . The light guide plate 102 is arranged on the circuit board 110 of the LED light source module 106, wherein the light incident surface 104 of the light guide plate 102 faces the light exit surfaces 112 of all the light emitting diodes 108, and the light exit surfaces 112 of the light emitting diodes 108 are in contact with the light guide plate The light incident surface 104 of 102 is in close contact with each other, as shown in FIG. 1A .

However, please refer to FIG. 1B , since the light emitting diodes 108 are point light sources, in the backlight module 100, the area close to the light emitting diodes 108 is brighter, and the area between the two light emitting diodes 108 is darker. It is called Hot Spot Mura114. The bright spot ripple 114 will affect the uniformity of the light source provided by the backlight module 100 , thereby degrading the display quality.

For the bright spot phenomenon, the common solution at present is to use a photomask or a plastic frame to cover the area with uneven brightness. However, such a method will increase the width of the frontal area between the visible area and the edge of the backlight module, which is not conducive to the miniaturization design of the current backlight module.

Another way to solve the bright spot phenomenon is to reduce the pitch of the LEDs of the LED light source module, so as to improve the bright spot ripple by increasing the arrangement density of the LEDs. However, reducing the pitch of the LEDs will increase the cost of the backlight module, which is not a good solution.

Contents of the invention

Therefore, one aspect of the present invention is to provide a backlight module, which can limit the light emitting angles of the light emitting diodes in the upper and lower directions, thereby controlling the angle at which the light emitted by the light emitting diodes enters the light guide plate, so that the light is more visible After moving forward from the center of the light guide plate, it emits light from the light-emitting surface of the light guide plate, so it can effectively reduce or even eliminate bright spot ripples at the light-entrance part of the light guide plate.

Another aspect of the present invention is to provide a backlight module, the bright spot phenomenon can be greatly improved or eliminated, so the distance between the light emitting diodes of the light emitting diode light source module can be increased, the number of light emitting diodes can be reduced, and the backlight can be reduced. The limbic area of the module.

Yet another aspect of the present invention is to provide a liquid crystal display, which can reduce or eliminate bright spot ripples of the backlight module while taking into account the size specifications of the display, so that the display quality of the liquid crystal display can be effectively improved under the original size specifications.

According to the above object of the present invention, a backlight module is proposed, comprising at least: a light guide plate with a light incident surface; a light emitting diode light source module arranged beside the light incident surface; and a reflector with an opening adjacent to the light incident surface, wherein the light emitting diode The light source module is arranged in the reflector and incident light is incident on the light-incident surface through the opening, and the height of the opening is smaller than the thickness of the light guide plate.

According to the object of the present invention, a liquid crystal display is proposed, which at least includes a liquid crystal display panel and a backlight module disposed on the back of the liquid crystal display panel. Wherein, the backlight module at least includes: a light guide plate with a light incident surface; an LED light source module disposed beside the light incident surface; and a reflector with an opening adjacent to the light incident surface, wherein the LED light source module is disposed on the reflector Light is incident on the light-incident surface through the opening, and the height of the opening is smaller than the thickness of the light guide plate.

Description of drawings

FIG. 1A is a partial cross-sectional schematic diagram of a conventional backlight module.

FIG. 1B is a schematic top view of a conventional backlight module.

FIG. 2A is a schematic partial cross-sectional view of a backlight module according to the first preferred embodiment of the present invention.

FIG. 2B is a schematic partial cross-sectional view of a backlight module according to a second preferred embodiment of the present invention.

FIG. 2C is a schematic partial cross-sectional view of a backlight module according to a third preferred embodiment of the present invention.

FIG. 2D is a schematic partial cross-sectional view of a backlight module according to a fourth preferred embodiment of the present invention.

3A shows the brightness distribution curve obtained when the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm, the thickness of the light guide plate is 4 mm, and the opening of the reflector is 4 mm.

FIG. 3B shows the brightness distribution curve obtained when the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm, the thickness of the light guide plate is 4 mm, and the opening of the reflector is 3.8 mm. .

Figure 3C shows the brightness distribution curve obtained when the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness of the light guide plate is 4mm, and the opening of the reflector is 3.6mm .

3D shows the brightness distribution curve obtained when the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm, the thickness of the light guide plate is 4 mm, and the opening of the reflector is 3 mm.

Figure 3E shows the brightness distribution curve obtained when the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness of the light guide plate is 4mm, and the opening of the reflector is 2.4mm .

Figure 4A shows the brightness distribution curve obtained when the thickness of the light guide plate is 4 mm, the opening of the reflector is 3.6 mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm. .

Figure 4B shows the brightness distribution curve obtained when the thickness of the light guide plate is 4 mm, the opening of the reflector is 3.6 mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5 mm picture.

Figure 4C shows the brightness distribution curve obtained when the thickness of the light guide plate is 4 mm, the opening of the reflector is 3.6 mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.08 mm. picture.

4D shows the brightness distribution curve obtained when the thickness of the light guide plate is 4mm, the opening of the reflector is 3mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm.

Figure 4E shows the brightness distribution curve obtained when the thickness of the light guide plate is 4mm, the opening of the reflector is 3mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5mm .

Figure 4F shows the brightness distribution curve obtained when the thickness of the light guide plate is 4 mm, the opening of the reflector is 2.4 mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm. .

Figure 4G shows the brightness distribution curve obtained when the thickness of the light guide plate is 4mm, the opening of the reflector is 2.4mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5mm picture.

Figure 4H shows the brightness distribution curve obtained when the thickness of the light guide plate is 4 mm, the opening of the reflector is 1.8 mm, and the distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 0.9 mm. picture.

FIG. 5 is a schematic partial cross-sectional view of a liquid crystal display according to a preferred embodiment of the present invention.

Explanation of reference signs

100: Backlight module 102: Light guide plate

104: Light incident surface 106: LED light source module

108: LED 110: Circuit board

112: light emitting surface 114: bright spot ripple

116: reflector 118: side panel

120: side panel 122: side panel

300a: Backlight module 300b: Backlight module

300c: Backlight module 300d: Backlight module

302a: Light guide plate 302b: Light guide plate

304: LED light source module

306: LED 308: Circuit board

310a: reflector 310b: reflector

310c: reflector 312: C-shaped structure

314a: Extension 314b: Extension

314c: extension 316: end

318: Light-emitting surface 320: Light-incoming surface

322a: opening 322b: opening

322c: Opening 324a: Height

324b: height 324c: height

326: Thickness 327: Distance

328: light 330: chamfering area

332: Non-leading corner area 334: Height

336: light emitting surface 338: back frame

340: Fixed bump 342: Hook

344: Front frame 346: Fixing hole

348: Opening 350: Graphics

352: Graphics 354: Graphics

358: Graphics 360: Graphics

364: Graphics 366: Graphics

370: Graphics 372: Graphics

376: Graphics 378: Graphics

380: Graphics 381: Graphics

382: Graphics 384: Graphics

385: Graphics 387: Graphics

388: Graphics 390: Graphics

391: Graphics 393: Graphics

394: Graphics 396: Graphics

397: Graphics 399: Graphics

400: Liquid crystal display 402: Liquid crystal display panel

403: Graphics 404: Graphics

405: Graphics 406: Graphics

AA': vertical axis BB': horizontal axis

Detailed ways

Please refer to FIG. 2A , which shows a partial cross-sectional view of a backlight module according to a first preferred embodiment of the present invention. In the exemplary embodiment, the backlight module 300a at least includes a light guide plate 302a, an LED light source module 304 and a reflector 310a. One side of the light guide plate 302 a has a light incident surface 320 , and the other side adjacent to this side of the light guide plate 302 a has a light exit surface 336 . The LED light source module 304 is disposed in the reflector 310a, and the combination of the LED light source module 304 and the reflector 310a is disposed beside the light incident surface 320 of the light guide plate 302a. The light guide plate 302a has a thickness 326 . In an embodiment, the light guide plate 302a may be, for example, a wedge-shaped plate structure or a flat plate structure. Wherein, when the light guide plate 302a is a plate structure with substantially the same thickness, the thickness at the light incident surface 320 can represent the thickness 326 of the light guide plate 302a; and when the light guide plate 302a is a wedge-shaped plate structure, the thickness 326 is the thickness of the thickest part of the entire light guide plate 302 a , usually the thickness at the light incident surface 320 . The light emitting diode light source module 304 mainly includes a circuit board 308 and several light emitting diodes 306, wherein each light emitting diode 306 has a light emitting surface 318, and these light emitting diodes 306 are arranged on the surface of the circuit board 308, the light emitting diode 306 The surface 318 is opposite to the light incident surface 320 of the light guide plate 302a.

The reflector 310 a at least includes a C-shaped structure 312 and two extensions 314 a , wherein the C-shaped structure 312 has an opening 348 , and the two extensions 314 a are connected to two ends 316 of the opening 348 of the C-shaped structure 312 . In this exemplary embodiment, each extension 314a is a flat plate, and the two extensions 314a are substantially horizontal and parallel to each other and are arranged on the two ends 316 of the opening 348 of the C-shaped structure 312 and the light incident of the light guide plate 302a. 320, and form an opening 322a in front of the light incident surface 320 of the light guide plate 302a, that is, the opening 322a of the reflector 310a is adjacent to the light incident surface 320 of the light guide plate 302a, so the LED light source module 304 can pass through the opening 322a. Light is incident on the light incident surface 320 of the light guide plate 302a. The distance from the opening 322a of the reflection cover 310a to the light incident surface 320 of the light guide plate 302a is fixed, wherein the reflection cover 310a is preferably in contact with the light incident surface 320 of the light guide plate 302a. The circuit board 308 of the LED light source module 304 is accommodated in the C-shaped structure 312 of the reflector 310a, and the light emitting surface 318 of each LED 306 is preferably interposed between the two extensions 314a. There is a distance 327 between the light emitting surface 318 of the LED 306 and the light incident surface 320 of the light guide plate 302a. Through the reflection and guidance of the extension portion 314a of the reflector 310a, the light 328 emitted by the LED 306 through the light output surface 318 can be guided into the light incident surface 320 in front of the opening 322a and enter the light guide plate 302a.

In this exemplary embodiment, the height 324a of the opening 322a of the reflection cover 310a is smaller than the thickness 326 of the light guide plate 302a, as shown in FIG. 2A . In an embodiment, when the thickness 326 of the light guide plate 302a is about 4mm, the height 324a of the opening 322a of the reflection cover 310a is preferably between about 3.0mm and about 3.8mm. Therefore, the height 324a of the opening 322a of the reflection cover 310a is preferably between substantially 3/4 to substantially 19/20 of the thickness 326 of the light guide plate 302a. By reducing the height 324a of the opening 322a of the reflector 310a, the distance between the reflective surfaces of the light emitting diode 306 in the upper and lower directions is reduced. In this way, the light emitting angle of the light emitting diode 306 in the upper and lower directions can be limited, thereby enabling The angle at which the light 328 emitted by the LED 306 enters the light guide plate 302a is controlled within an appropriate range, which can reduce the brightness of the light guide plate 302a directly in front of the LED 306, thereby effectively solving the bright spot ripple of the backlight module 300a. The smaller the height 324a of the opening 322a of the reflector 310a, the lighter the bright spot ripple of the backlight module 300a, and the shorter the distance 327 between the light emitting surface 318 of the LED 306 and the light incident surface 320 of the light guide plate 302a, However, the bright lines of the light guide plate 302a are more obvious. In an exemplary embodiment, the ratio of the distance 327 between the light emitting surface 318 of the LED 306 and the light incident surface 320 of the light guide plate 302a to the height 324a of the opening 322a of the reflector 310a is preferably greater than or equal to 30%.

The reflector of the backlight module of the present invention can have other different designs. Please refer to FIG. 2B , which shows a partial cross-sectional view of a backlight module according to a second preferred embodiment of the present invention. In this exemplary embodiment, the device design of the backlight module 300b is substantially the same as that of the backlight module 300a of the first embodiment. The structural design is different. In the backlight module 300b, the reflector 310b mainly includes a C-shaped structure 312 and two extensions 314b, wherein the two extensions 314b are also connected to the two ends 316 of the opening 348 of the C-shaped structure 312, and each extension 314b for tablet. In this exemplary embodiment, the two extensions 314b are arranged on the opening of the C-shaped structure 312 in such a way that they are inclined outward from the two ends 316 of the opening 348 of the C-shaped structure 312 toward the direction of the light incident surface 320 of the light guide plate 302a. Between the two ends 316 of 348 and the light incident surface 320 of the light guide plate 302a, an opening 322b is formed in front of the light incident surface 320 of the light guide plate 302a, so the LED light source module 304 can face the light guide plate through the opening 322b of the reflector 310b Light is incident on the light incident surface 320 of 302a. The distance from the opening 322b of the reflection cover 310b to the light incident surface 320 of the light guide plate 302a is fixed, wherein the reflection cover 310b is preferably in contact with the light incident surface 320 of the light guide plate 302a. In another embodiment, the two extensions of the reflector can also be arranged on the C-shaped structure in a way that inclines inwardly from the two ends of the opening of the C-shaped structure of the reflector toward the light incident surface 320 of the light guide plate 302a. Between the two ends 316 of the opening of the structure and the light incident surface 320 of the light guide plate 302a. Likewise, the circuit board 308 of the LED light source module 304 is accommodated in the C-shaped structure 312 of the reflector 310b, and the light emitting surface 318 of each LED 306 is preferably interposed between the two extensions 314b.

In this exemplary embodiment, the height 324b of the opening 322b of the reflection cover 310b is smaller than the thickness 326 of the light guide plate 302a, as shown in FIG. 2B . In an embodiment, the height 324b of the opening 322b of the reflection cover 310b is preferably between substantially 3/4 to substantially 19/20 of the thickness 326 of the light guide plate 302a. In an exemplary embodiment, the ratio of the distance 327 between the light emitting surface 318 of the LED 306 and the light incident surface 320 of the light guide plate 302a to the height 324b of the opening 322b of the reflector 310b is preferably greater than or equal to 30%.

Please refer to FIG. 2C , which shows a partial cross-sectional view of a backlight module according to a third preferred embodiment of the present invention. In this exemplary embodiment, the device design of the backlight module 300c is substantially the same as that of the backlight module 300a of the first embodiment. The structural design is different. In the backlight module 300c, the reflector 310c mainly includes a C-shaped structure 312 and two extensions 314c, wherein the two extensions 314c are respectively connected to the two ends 316 of the opening 348 of the C-shaped structure 312, but each extension 314c It is not a flat plate but a curved plate. In this exemplary embodiment, the two extensions 314b are respectively disposed between the two ends 316 of the opening 348 of the C-shaped structure 312 and the light incident surface 320 of the light guide plate 302a. and an opening 322c is formed in front of the light incident surface 320 of the light guide plate 302a, so the LED light source module 304 can incident light toward the light incident surface 320 of the light guide plate 302a through the opening 322c of the reflector 310c. The distance from the opening 322c of the reflection cover 310c to the light incident surface 320 of the light guide plate 302a is fixed, wherein the reflection cover 310c is preferably in contact with the light incident surface 320 of the light guide plate 302a. Likewise, the circuit board 308 of the LED light source module 304 is accommodated in the C-shaped structure 312 of the reflector 310c, and the light-emitting surface 318 of each LED 306 is preferably located between the two extensions 314c.

In this exemplary embodiment, the height 324c of the opening 322c of the reflection cover 310c is smaller than the thickness 326 of the light guide plate 302a, as shown in FIG. 2C . In an embodiment, the height 324c of the opening 322c of the reflection cover 310c is preferably between substantially 3/4 to substantially 19/20 of the thickness 326 of the light guide plate 302a. In an exemplary embodiment, the ratio of the distance 327 between the light emitting surface 318 of the LED 306 and the light incident surface 320 of the light guide plate 302a to the height 324c of the opening 322c of the reflector 310c is preferably greater than or equal to 30%.

Please refer to FIG. 2D , which shows a partial cross-sectional view of a backlight module according to a fourth preferred embodiment of the present invention. In this exemplary embodiment, the device design of the backlight module 300d is substantially the same as the backlight module 300d of the first embodiment, the difference between the two lies in the structural design of the light guide plates 302b and 302a. In the backlight module 300d, the light guide plate 302b is composed of a chamfered area 330 and a non-chamfered area 332, wherein the chamfered area 330 is adjacent to the LED light source module 304 and the reflector 310a, and the entrance of the light guide plate 302b The optical surface 320 is located on a side surface of the chamfer region 330 adjacent to the opening 322a. In this exemplary embodiment, the non-bevel region 332 may be a flat plate structure or a wedge-shaped plate structure. Therefore, the thickness 326 of the light guide plate 302 b is the thickness at the non-corner region 332 .

In this exemplary embodiment, the height 324a of the opening 322a of the reflective cover 310a is less than or equal to the height 334 of the light incident surface 320 of the corner region 330 of the light guide plate 302b adjacent to the opening 322a of the reflective cover 310a, as shown in FIG. 2D . In an embodiment, the height 324a of the opening 322a of the reflector 310a is smaller than the thickness 326 of the light guide plate 302b. In a preferred embodiment, the height 324a of the opening 322a of the reflection cover 310a is preferably between substantially 3/4 to substantially 19/20 of the thickness 326 of the light guide plate 302b. The distance from the opening 322 a of the reflection cover 310 a to the light incident surface 320 of the light guide plate 302 b is fixed, wherein the reflection cover 310 a is preferably in contact with the light incident surface 320 of the corner area 330 .

Although in the above-mentioned backlight module 300d of the fourth embodiment, the reflector 310a of the first embodiment is matched with the light guide plate 302b, but the reflector adopted in other embodiments above, such as the reflector 310b and its variations type, and the reflector 310c can replace the reflector 310a used in the backlight module 300d.

FIG. 3A and FIG. 4H are diagrams showing simulation results using three LEDs as light sources. Please refer to FIG. 3A first, which shows that when the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness 326 of the light guide plate is 4mm, and the opening 324a of the reflector is 4mm, Obtained luminance distribution curves. The graph 350 of Fig. 3A is the luminance distribution diagram of the light-emitting surface 336 of the light guide plate, wherein the upper edge of the graph 350 is the light-incident surface 320, and the graph 352 is the brightness intensity curve obtained along the horizontal axis BB' of the graph 350, and the graph 354 is the brightness intensity curve obtained along the vertical axis AA′ of the graph 350 . In FIG. 3A, when the thickness of the light guide plate is 4mm and the height of the opening of the reflector is 4mm, it can be seen from the graph 352 that there are still obvious fluctuations in the lateral brightness distribution of the light guide plate, so in this situation The highlights are obvious. In addition, from the longitudinal luminance distribution of the graph 354, it can be seen that the luminance will be evenly distributed after a certain distance between the inside of the light guide plate and the light incident surface, which shows that the non-visible area of the light guide plate has a larger range.

Please refer to FIG. 3B, which shows that when the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness 326 of the light guide plate is 4mm, and the opening 324a of the reflector is 3.8mm, Obtained luminance distribution curves. In Fig. 3B, when the thickness of the light guide plate is 4 mm and the height of the opening of the reflector is reduced to 3.8 mm, it can be seen from the graph 358 that the fluctuation of the lateral brightness distribution of the light guide plate has become gentle, so in this situation , the bright spot phenomenon in the non-visible area has been effectively improved. In addition, it can be seen from the longitudinal luminance distribution of the graph 360 that as the opening of the reflector decreases, the scope of the non-visible area of the light guide plate becomes smaller.

Please refer to FIG. 3C, which shows that when the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness 326 of the light guide plate is 4mm, and the opening 324a of the reflector is 3.6mm, Obtained luminance distribution curves. In Fig. 3C, when the thickness of the light guide plate is 4 mm and the height of the opening of the reflector is reduced to 3.6 mm, it can be seen from the graph 364 that the fluctuation of the lateral brightness distribution of the light guide plate is higher than that of the reflector when the height of the opening is 3.8 mm However, under this condition, bright lines will be formed in the light guide plate close to the light incident surface. In addition, from the longitudinal brightness distribution of the graphic 366, it can be seen that the range of the non-visible area of the light guide plate is slightly smaller than that of the reflector when the opening height is 3.8 mm.

Please refer to FIG. 3D, which shows that when the distance 327 between the light-emitting surface of the LED and the light-incident surface of the light guide plate is 1mm, the thickness 326 of the light guide plate is 4mm, and the opening 324a of the reflector is 3mm. Obtained luminance distribution curves. In FIG. 3D, when the thickness of the light guide plate is 4 mm and the height of the opening of the reflector is reduced to 3 mm, it can be seen from the graph 370 that the fluctuation of the lateral brightness distribution of the light guide plate is gentler than that when the height of the opening of the reflector is 3.6 mm. . In addition, from the longitudinal brightness distribution of the graph 372, it can be seen that the range of the non-visible area of the light guide plate is slightly smaller than that of the reflector when the opening height is 3.6 mm. However, there are relatively obvious bright lines in the non-visible area of the light guide plate at this time.

Please refer to FIG. 3E, which shows that when the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the thickness 326 of the light guide plate is 4mm, and the opening 324a of the reflector is 2.4mm, Obtained luminance distribution curves. In FIG. 3E, when the thickness of the light guide plate is 4 mm and the height of the opening of the reflector is reduced to 2.4 mm, it can be seen from the graph 376 that the fluctuation of the lateral brightness distribution of the light guide plate is gentler than that when the height of the opening of the reflector is 3 mm. . In addition, from the longitudinal brightness distribution of the graphic 378, it can be seen that the range of the non-visible area of the light guide plate is slightly smaller than that of the reflector when the opening height is 3mm. However, at this time, the bright lines in the non-visible area of the light guide plate are more obvious.

Please refer to FIG. 4A, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 3.6mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, Obtained luminance distribution curves. Graph 380 in FIG. 4A is a luminance distribution diagram of the light-emitting surface 336 of the light guide plate, wherein the upper edge of the graph 380 is the light-incident surface 320, and the graph 381 is the brightness intensity curve obtained along the horizontal axis BB' of the graph 380, and the graph 382 is the brightness intensity curve obtained along the vertical axis AA′ of the graph 380 . The distance between the light emitting surface of the light emitting diode and the light incident surface of the light guide plate is 1 mm, and the height of the opening of the reflector is 3.6 mm, so the ratio of the distance to the opening is about 27.8%. In FIG. 4A , it can be seen from the graph 381 that the fluctuation of the lateral luminance distribution of the light guide plate is relatively gentle, so the phenomenon of bright spots in the non-visible area is somewhat improved. From the longitudinal brightness distribution of the graph 382, it can be seen that as the opening of the reflector decreases, the scope of the non-visible area of the light guide plate becomes smaller.

Please refer to FIG. 4B, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 3.6mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5mm. , the obtained brightness distribution curve. Wherein, the graph 385 is the longitudinal brightness distribution of the light-emitting surface 336 of the light guide plate. The distance between the light-emitting surface of the LED and the light-incident surface of the light guide plate is 1.5 mm, and the height of the opening of the reflector is 3.6 mm, so the ratio of the distance to the opening increases to about 41.67%. In FIG. 4B , it can be seen from the graph 384 that the fluctuation of the lateral brightness distribution of the light guide plate is gentler than that when the distance is 1 mm, so the phenomenon of bright spots in the non-visible area is further improved.

Please refer to FIG. 4C, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 3.6mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.08mm. , the obtained brightness distribution curve. Wherein, the graph 388 is the longitudinal brightness distribution of the light-emitting surface 336 of the light guide plate. The distance between the light emitting surface of the light emitting diode and the light incident surface of the light guide plate is 1.08 mm, and the height of the opening of the reflector is 3.6 mm, so the ratio of the distance to the opening increases to about 30%. In FIG. 4C , it can be seen from the graph 387 that the fluctuation of the lateral brightness distribution of the light guide plate is gentler than when the distance is 1 mm, but the fluctuation is larger than that when the distance is 1.5 mm, so the phenomenon of bright spots in the non-visible area is more than when the distance is 1 mm. Improved, but more obvious than when the distance is 1.5mm.

Please refer to FIG. 4D, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 3mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, the Obtained luminance distribution curve. Wherein, the graph 391 is the longitudinal brightness distribution of the light-emitting surface 336 of the light guide plate. The distance between the light emitting surface of the LED and the light incident surface of the light guide plate is 1 mm, and the height of the opening of the reflector is reduced to 3 mm, so the ratio of the distance to the opening increases to about 33.33%. In FIG. 4D , it can be seen from the graph 390 that the fluctuation of the lateral luminance distribution of the light guide plate is gentler than that when the distance is the same as 1 mm but the opening height of the reflector is 3.6 mm. Therefore, the bright spot phenomenon in the non-visible area is 3.6 mm higher than the opening height of the reflector. Improved at 3.6mm.

Please refer to FIG. 4E, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 3mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5mm, Obtained luminance distribution curves. Wherein, the graph 394 is the vertical brightness distribution of the light-emitting surface 336 of the light guide plate. The distance between the light emitting surface of the LED and the light incident surface of the light guide plate is increased to 1.5 mm, and the height of the opening of the reflector is maintained at 3 mm, so the ratio of the distance to the opening is increased to 50%. In FIG. 4E , it can be seen from the graph 393 that the fluctuation of the lateral luminance distribution of the light guide plate is gentler than that when the distance is 1 mm, so the phenomenon of bright spots in the non-visible area is improved compared with that when the distance is 1 mm.

Please refer to FIG. 4F, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 2.4mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1mm, Obtained luminance distribution curves. The distance between the light-emitting surface of the LED and the light-incident surface of the light guide plate is 1 mm, and the height of the opening of the reflector is further reduced to 2.4 mm, so the ratio of the distance to the opening increases to about 41.67%. In FIG. 4F, it can be seen from the graph 396 that the fluctuation of the lateral brightness distribution of the light guide plate is gentler than when the distance is the same as 1 mm but the opening height of the reflector is 3 mm. Therefore, the bright spots in the non-visible area are compared with the reflector opening height of 3 mm. time to improve. From the vertical luminance distribution of the graph 397, it can be seen that the luminance of the non-visible area of the light guide plate is greater than that of the reflector when the opening height is 3 mm, so the phenomenon of bright lines is more obvious.

Please refer to FIG. 4G, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 2.4mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 1.5mm. , the obtained brightness distribution curve. Wherein, the graph 403 is the longitudinal brightness distribution of the light-emitting surface 336 of the light guide plate. The distance between the light emitting surface of the LED and the light incident surface of the light guide plate is increased to 1.5mm, and the height of the opening of the reflector is maintained at 2.4mm, so the ratio of the distance to the opening at this time is increased to 62.5%. In FIG. 4G , it can be seen from the graph 399 that the fluctuation of the lateral luminance distribution of the light guide plate is obviously gentler than that when the distance is 1 mm, so the phenomenon of bright spots in the non-visible area is improved compared with that when the distance is 1 mm.

Please refer to FIG. 4H, which shows that when the thickness 326 of the light guide plate is 4mm, the opening 324a of the reflector is 1.8mm, and the distance 327 between the light emitting surface of the LED and the light incident surface of the light guide plate is 0.9mm. , the obtained brightness distribution curve. Graph 404 in FIG. 4H is the brightness distribution graph on the light guide plate, graph 405 is the brightness intensity curve obtained along the horizontal axis BB' of graph 404, and graph 406 is obtained along the vertical axis AA' of graph 404 Brightness intensity curve. The distance between the light emitting surface of the LED and the light incident surface of the light guide plate is shortened to 0.9mm, and the height of the opening of the reflector is further reduced to 1.8mm, so the ratio of the distance to the opening increases to about 50%. In FIG. 4H , it can be seen from the graph 405 that the lateral luminance distribution of the light guide plate fluctuates greatly due to the shortening of the distance. It can be seen from the longitudinal luminance distribution of the graph 406 that although the distance is shortened, the non-visible area of the light guide plate is smaller because the opening of the reflector becomes smaller.

It can be seen from FIG. 4A to FIG. 4H that the smaller the opening of the reflector, the lighter the bright spot phenomenon, and the shorter the distance between the light emitting surface of the LED and the light incident surface of the light guide plate. However, the smaller the opening of the reflector, the more obvious the bright lines in the non-visible area of the light guide plate.

The above-mentioned backlight modules can be applied to liquid crystal displays, and the backlight module 300a is taken as an example below. Please refer to FIG. 5 , which shows a partial cross-sectional view of a liquid crystal display according to a preferred embodiment of the present invention. In the exemplary embodiment, the liquid crystal display 400 mainly includes a liquid crystal display panel 402 and a backlight module 300a, wherein the backlight module 300a is disposed on the back of the liquid crystal display panel 402 to provide a backlight for the liquid crystal display panel 402 . In an embodiment, the backlight module 300a can be further provided with a back frame 338 and a front frame 344 according to product requirements, so as to support and fix the structure of the backlight module 300a. The light guide plate 302a, the LED light source module 304 and the reflector 310a are all arranged on the back frame 338, wherein the back frame 338 can also selectively protrude with a fixed protrusion 340, and the fixed protrusion 340 is blocked by the reflector 310a. between the C-shaped structure 312 of the light guide plate 302a and the light incident surface 320 of the light guide plate 302a, to fix the position of the reflector 310a and the LED light source module 304 disposed therein, and to keep the opening 322a of the reflector 310a in the light guide plate 302a Next to the light incident surface 320 . The front frame 344 covers the outer edge of the light guide plate 302a, the LED light source module 304 and the reflector 310a, and one side of the front frame 344 extends to cover the outer surface of the reflector 310a and the back frame 338. Optionally, the back frame 338 further has a hook 342, and the front frame 344 is correspondingly provided with a fixing hole 346 at a position corresponding to the hook 342 of the back frame 338, wherein the hook 342 of the back frame 338 and the fixing hole of the front frame 344 346 can match each other and snap together. The liquid crystal display panel 402 can be erected on the front frame 344 and carried by the front frame 344 .

It can be seen from the above exemplary embodiments that the advantage of the present invention is that the backlight module of the present invention can limit the light emission angles of the light emitting diodes in the upper and lower directions, thereby controlling the angle at which the light emitted by the light emitting diodes enters the light guide plate, so that the light is brighter. Going toward the center of the visible area and then emitting from the light exit surface of the light guide plate, it can effectively reduce or even eliminate the bright spot ripples at the light entrance of the light guide plate.

It can be seen from the above exemplary embodiments that another advantage of the present invention is that the bright spot phenomenon of the backlight module of the present invention can be greatly improved or eliminated, so the distance between the LEDs of the LED light source module can be increased, and the distance between the LEDs can be reduced. The quantity used can reduce the frontal area of the backlight module.

It can be seen from the above-mentioned exemplary embodiments that another advantage of the present invention is that the liquid crystal display of the present invention can effectively reduce or substantially eliminate the bright spot ripple of the backlight module while taking into account the size specifications of the display. Therefore, under the original size specifications, effective Improve the display quality of LCD monitors.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Modification, therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (12)

1. A backlight module, comprising at least: The light guide plate has a light incident surface; a light emitting diode light source module is arranged beside the light incident surface; and The reflection cover has an opening adjacent to the light incident surface, wherein the LED light source module is arranged in the reflection cover and incident light is incident on the light incident surface through the opening, the height of the opening is smaller than the thickness of the light guide plate, wherein, The reflector at least includes a C-shaped structure and two extensions, wherein the C-shaped structure has an opening, and the two extensions are respectively connected to the two ends of the opening of the C-shaped structure, each extension is a flat plate, and the two extensions The portion is arranged between the two ends of the opening of the C-shaped structure and the light incident surface of the light guide plate in a substantially horizontal and parallel manner, and forms an opening on the light incident surface of the light guide plate. 2. The backlight module as claimed in claim 1, wherein the height of the opening is between substantially 3/4 to substantially 19/20 of the thickness of the light guide plate. 3. The backlight module as claimed in claim 1, wherein the light guide plate is a wedge-shaped plate structure. 4. The backlight module as claimed in claim 1, wherein the light guide plate at least comprises: non-bevel areas; and The chamfered area, wherein the light incident surface is disposed on one side of the chamfered area and the chamfered area is adjacent to the LED light source and the reflector. 5. A backlight module, comprising at least: The light guide plate has a light incident surface; A light emitting diode light source module is arranged beside the light incident surface, wherein the light emitting diode light source module includes at least a plurality of light emitting diodes, each of the light emitting diodes has a light emitting surface, and there is a distance between the light emitting surface and the light incident surface; as well as The reflection cover has an opening adjacent to the light-incident surface, wherein the light-emitting diode light source module is arranged in the reflection cover and incident light is incident on the light-incident surface through the opening, and the ratio of the distance to the height of the opening is greater than or equal to 30 %, wherein the reflector at least includes a C-shaped structure and two extensions, wherein the C-shaped structure has an opening, and the two extensions are respectively connected to the two ends of the opening of the C-shaped structure, each extension is a flat plate, and The two extensions are arranged between the two ends of the opening of the C-shaped structure and the light incident surface of the light guide plate in a substantially horizontal and parallel manner, and form an opening on the light incident surface of the light guide plate, wherein the height of the opening is less than The thickness of the light guide plate. 6. The backlight module as claimed in claim 5, wherein the height of the opening is between substantially 3/4 to substantially 19/20 of the thickness of the light guide plate. 7. The backlight module as claimed in claim 5, wherein the light guide plate is a wedge-shaped plate structure. 8. The backlight module as claimed in claim 5, wherein the light guide plate at least comprises: non-bevel areas; and The chamfered area, wherein the light incident surface is disposed on one side of the chamfered area and the chamfered area is adjacent to the LED light source and the reflector. 9. A liquid crystal display, comprising at least: liquid crystal display panel; and A backlight module is arranged on the back of the liquid crystal display panel, wherein the backlight module at least includes: The light guide plate has a light incident surface; a light emitting diode light source module is arranged beside the light incident surface; and The reflection cover has an opening adjacent to the light incident surface, wherein the LED light source module is arranged in the reflection cover and incident light is incident on the light incident surface through the opening, the height of the opening is smaller than the thickness of the light guide plate, wherein, The reflector includes at least a C-shaped structure and three extensions, wherein the C-shaped structure has an opening, and the two extensions are respectively connected to the two ends of the opening of the C-shaped structure, each extension is a flat plate, and the two extensions The portion is arranged between the two ends of the opening of the C-shaped structure and the light incident surface of the light guide plate in a substantially horizontal and parallel manner, and forms an opening on the light incident surface of the light guide plate. 10. The liquid crystal display as claimed in claim 9, wherein the height of the opening is between substantially 3/4 to substantially 19/20 of the thickness of the light guide plate. 11. A liquid crystal display, comprising at least: liquid crystal display panel; and A backlight module is arranged on the back of the liquid crystal display panel, wherein the backlight module at least includes: The light guide plate has a light incident surface; A light emitting diode light source module is arranged beside the light incident surface, wherein the light emitting diode light source module includes at least a plurality of light emitting diodes, each of the light emitting diodes has a light emitting surface, and there is a distance between the light emitting surface and the light incident surface; as well as The reflection cover has an opening adjacent to the light-incident surface, wherein the light-emitting diode light source module is arranged in the reflection cover and incident light is incident on the light-incident surface through the opening, and the ratio of the distance to the height of the opening is greater than or equal to 30 %, wherein the reflector at least includes a C-shaped structure and two extensions, wherein the C-shaped structure has an opening, and the two extensions are respectively connected to the two ends of the opening of the C-shaped structure, each extension is a flat plate, and The two extensions are arranged between the two ends of the opening of the C-shaped structure and the light incident surface of the light guide plate in a substantially horizontal and parallel manner, and form an opening on the light incident surface of the light guide plate, wherein the height of the opening is less than The thickness of the light guide plate. 12. The liquid crystal display as claimed in claim 11, wherein the height of the opening is between substantially 3/4 to substantially 19/20 of the thickness of the light guide plate.