TWI459089B - Light guide plate and backlight module having the same - Google Patents

Description

Light guide plate and backlight module

The present invention relates to a backlight module and a light guide plate included in the backlight module; in particular, an edge-light backlight module using a light-emitting diode and a light guide plate included in the backlight module.

The LCD panel is the mainstream of current display devices, and is widely used in various types of panel displays, flat screens for homes, flat-panel monitors for personal computers and laptops, display screens for mobile phones and digital cameras, etc. electronic product. In addition, the side light type backlight module in which the light source is disposed on the periphery of the light guide plate has a thinner module thickness than the direct type backlight module in which the light source is uniformly disposed behind the light guide plate, thereby enabling the edge light type flat panel display The market that emphasizes thinness is now more competitive.

1A is a top view of a conventional edge-lit backlight module 10 using a light-emitting diode as a light source. As shown in FIG. 1A, the conventional edge-lit backlight module 10 includes a light guide plate 20 and a light bar 13 composed of a plurality of light-emitting diodes 11, wherein the light-emitting diodes 11 are disposed around the light guide plate 20 and are guided. The light incident end face 31 of the light plate 20 emits light. In addition, FIG. 1B is a cross-sectional view of the conventional edge-lit backlight module 10 of FIG. 1A according to a section line AA'. As shown in FIG. 1B, the conventional edge-lit backlight module 10 further includes a reflective plate 50 for reflecting light.

Please refer to the top view shown in FIG. 1A and the cross-sectional view shown in FIG. 1B. As shown in FIG. 1B, the light A emitted from the light source 12 of the self-luminous diode 11 is totally reflected inside the light guide plate 20 for transmission, and then contacts the microstructure of the bottom surface of the light guide plate 20 (not shown) to cause total reflection. The light is destroyed and thus emitted from one side of the light guide plate 20 with respect to the reflection plate 50.

In order to reduce the overall thickness of the conventional edge-lit backlight module 10, the thickness of the central portion of the light guide plate 20 corresponding to the panel display area (Active Area) is reduced to be smaller than the height of the light-emitting diode 11. However, in order to completely receive the light emitted from the light source 12 of the light-emitting diode 11, the portion of the light guide plate 20 close to the light source protrudes to form a wedge-shaped structure, and thus has a height equivalent to that of the light-emitting diode 11. As a result, the protruding portion of the light guide plate 20 has a larger area to receive the light generated by the light source 12 to improve the utilization of the light.

However, the above-mentioned conventional edge-lit backlight module 10 still has optical disadvantages. The light generated by the portion of the self-luminous diode 11 will be transmitted through the guiding slope 32 of the protruding portion of the light guide plate 20 or the position of the light guide plate 20 near the guiding slope 32, thereby causing the brightness of the edge portion of the visible portion of the backlight module 10. Uneven on the top. For example, the light B generated by the self-luminous diode 11 will travel toward the surface of the reflective plate 50 after the contact guiding slope 32 and the reflecting plate 50 are reflected, and then the light B will be incident on the surface of the light guiding plate 20. The angle is smaller than the corresponding critical angle, and the light is directly emitted from the edge surface of the light guide plate 20 near the guiding slope 32. As a result, the edge of the light guide plate 20 will be significantly brighter than the other portions due to the specific observation angle and thus give the viewer a bright line of glare.

It can be seen that how to simultaneously produce uniform front view brightness and avoid bright lines or other optical defects while reducing the overall thickness of the backlight module is an important issue in the production and design of the backlight module.

An object of the present invention is to provide a light guide plate having a structure for reducing light leakage into a light portion and a backlight module including the light guide plate to reduce the light leakage visual phenomenon generated by the backlight module.

Another object of the present invention is to provide a light guide plate having a structure for reducing light leakage into a light portion and a backlight module including the light guide plate to uniformly emit a front view brightness of the backlight module in the display area.

The backlight module of the present invention comprises a light source and a light guide plate, wherein the light guide plate further comprises a body and a bent light entrance portion. The body of the light guide plate includes a light emitting surface and a bottom surface opposite to the light emitting surface. The bent light-incident portion of the light guide plate extends from one side of the body and is bent toward the back surface of the body. The bending light entrance portion includes a light incident end surface, a first guiding inclined surface and a second guiding inclined surface, wherein the light source is disposed at a position corresponding to the light incident end surface and emits light toward the light incident end surface.

One end of the first guiding slope intersects the light emitting surface of the body at the first boundary, and the other end of the first guiding slope is connected to the top edge of the optical end surface. On the other hand, one end of the second guiding slope intersects the bottom surface of the body at the second boundary, and the other end of the second guiding slope is connected to the bottom edge of the optical end surface. In addition, the acute angle between the first guiding inclined surface and the extending surface of the body toward the light-incident end surface is a first angle, and the second guiding inclined surface and the bottom surface of the body are inclined at an acute angle of the extending line of the light-incident end surface. It is a second angle, wherein the first angle is preferably greater than the second angle, but is not limited thereto.

In one embodiment of the invention, the second guiding ramp is a substantially uneven surface, wherein the second guiding ramp comprises a first sub-slope and a second sub-slope. One end of the first sub-bevel is connected to the light incident end face. One end of the second sub-slope intersects the bottom surface of the body at the second boundary, and the other end connects the first sub-slope to the third boundary. In addition, the acute angle between the first sub-slope and the extension of the bottom surface toward the light-incident end surface is a third angle. The acute angle between the second sub-slope and the extension of the bottom surface toward the light-incident end surface is a fourth angle, wherein the third angle is preferably greater than the fourth angle, but is not limited thereto.

In another embodiment of the present invention, the light guide plate further includes a plurality of second guiding slopes and a plurality of corresponding auxiliary guiding slopes, wherein the second guiding slopes are spaced apart along the bottom edge of the light incident end surface. The auxiliary guiding slope is formed between the adjacent second guiding slopes, wherein one end of the auxiliary guiding slope intersects the bottom surface of the body at the second boundary, and the other end is connected to the bottom edge of the optical end surface.

The present invention relates to a backlight module and a light guide plate included in the backlight module; in particular, a backlight module using a light emitting diode and a light guide plate included in the backlight module.

2A is a top view of the backlight module 100 of the present invention, and FIG. 2B is a cross-sectional view of the backlight module 100 of FIG. 2A according to a line AA'. Referring to FIG. 2A and FIG. 2B simultaneously, the backlight module 100 of the present invention includes the light strip 130 of the plurality of light-emitting elements 110 and the light guide plate 200. The light guide plate 200 includes a main body 210 and a light-incident light-incident portion 300. The light-emitting element 110 is disposed on one side of the light-guiding plate 200 corresponding to the light-incident light-emitting portion 300 and emits light to the light-incident end surface 310 bent into the light-emitting portion 300. In addition, in the embodiment shown in FIG. 2A and FIG. 2B, the backlight module 100 is disposed on only one side of the light guide plate 200, but is not limited thereto; in different embodiments, the backlight module 100 can also be simultaneously The light-emitting element 110 and the position of the light-incorporating portion 300 on opposite sides of the light guide plate 200 are disposed.

In the embodiment shown in FIG. 2A and FIG. 2B, the body 210 has a light-emitting surface 211 and a bottom surface 212 opposite to the light-emitting surface 211. The light A generated by the light-emitting element 110 will enter the light guide plate 200 and be guided by total reflection. The light plate 200 travels inside and is totally totally reflected after being exposed to the microstructure (not shown) of the bottom surface 212 of the light guide plate 200 and exits the light guide plate 200 from the light exit surface 211 after being scattered. In addition, the light-emitting element 110 of the present embodiment is a plurality of light-emitting diodes, but is not limited thereto. In various embodiments, the backlight module 100 may also use an illuminant such as a cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp). As the light emitting element 110.

Please refer to the top view of FIG. 2A and the cross-sectional view of FIG. 2B at the same time. The bent light entrance portion 300 extends from one side of the body 210 and is bent toward the back surface 212. The bending light incident portion 300 includes a light incident end surface 310, a first guiding slope 320, and a second guiding slope 330. The light emitting element 110 is disposed at a position corresponding to the light incident end surface 310 and emits light toward the light incident end surface 310.

One end of the first guiding slope 320 and the light-emitting surface 211 intersect the first boundary 213 and the other end is connected to the top edge of the light-incident end surface 310 near the light-emitting surface 211. On the other hand, one end of the second guiding slope 330 and the bottom surface 212 intersect at the second boundary 214 and the other end is connected to the bottom edge of the light end surface 310 near the bottom surface 212. It can be seen that the first guiding slope 320 and the second guiding slope 330 of the present invention are respectively located on the upper and lower sides of the light incident end surface 310, thereby reflecting the light generated by the light emitting element 310 and guiding it to the guide. The inside of the body 210 of the light plate 200 is configured such that a microstructure layer (not shown) located on the bottom surface 212 of the body 210 breaks the total reflection of the light and causes it to be emitted from the light exit surface 211.

In the embodiment shown in FIG. 2B, the acute angle between the extension lines of the first guiding slope 320 and the light-emitting surface 211 toward the light-incident end surface 310 is a first angle θ ₁ and the second guiding slope 330 and the bottom surface 212 are facing. The acute angle between the extension lines of the light incident end face 310 is a second angle θ ₂ , wherein the first angle θ _{1 of} the embodiment is greater than the second angle θ ₂ , but is not limited thereto; in various embodiments, the backlight of the present invention The module 100 can also adjust the first guiding slope 320 and the corresponding first angle θ ₁ or the second guiding slope 330 according to the position of the light emitting element 110, the interval of the adjacent light emitting elements 110 or other design requirements. The second angle θ _{2 is} to change the ratio between the first angle θ ₁ and the second angle θ ₂ or to make the second angle θ ₂ greater than the first angle θ ₁ .

As shown in FIG. 2B, the light A generated by the light source 121 is reflected and contacts the light exit surface 211 of the body 210 after contacting the first guiding slope 320 and the second guiding slope 330, wherein the second guiding slope 330 is The inclination increases the incident angle at which the light A contacts the light exit surface 211. In this way, the light A will travel in the light guide plate 200 due to the incident angle greater than the critical angle, and finally exit from the light exit surface 211 after being completely reflected by the microstructure of the light guide plate 200. Light guide plate 200. Thereby, the structure shown in FIG. 2B prevents the light A from being scattered by the first guiding slope 320 or the second guiding slope 330 before entering the body 210 of the light guide plate 200 and can maintain total reflection travel before entering the body 210, It is finally allowed to emit light from the light exit surface 211 after being destroyed by the microstructure.

In addition, in this embodiment, the light-emitting element 110 and the light-incident end surface 310 of the light-incident light-emitting portion 300 have a space including air, but are not limited thereto; in different embodiments, the backlight module 100 of the present invention may be based on a light source. The relative position between the 120 and the light incident end face 310 and the light emitting intensity of the light emitting element 110, the spacing of the adjacent light emitting elements 110, or other demanding selectivity selectively selects the light emitting element 110 and the light incident end face of the light incident portion 300. 310 are affixed to each other.

2C is a side view of the backlight module 100 of FIG. 3 viewed from the side of the light-emitting element 110 on the side of the light guide plate 200. Referring to FIG. 2B and FIG. 2C simultaneously, in order to increase the light received by the light incident end surface 310, the height of the bottom edge of the light source 120 is preferably higher than the bottom edge 310b of the light incident end surface 310, and the height of the top end of the light source 120. Preferably, it is lower than the top edge 310c corresponding to the light incident end surface 310. In this way, the vertical projection of the surface of the light source 120 on the plane of the light incident end surface 310 is covered by the light incident end surface 310, so that more light generated by the light source 120 can be received. In addition, the light source center 121 of the light source 120 of the present embodiment is preferably lower than the height of the light incident end surface 310a of the light incident end surface 310, but is not limited thereto. In various embodiments, the backlight module 100 of the present invention may also be based on the light source. The ratio of the height between the 120 and the light incident end face 310 or other requirements adjusts the height of the light source center 121 relative to the center of the light incident end face 310a.

In addition, the interval between the light-emitting elements 110 can be adjusted according to the angular distribution range of the light generated by the light-emitting element 110 and the intensity of the light generated by the light-emitting element 110. In other words, the backlight module 100 of the present invention can adjust the interval between adjacent light-emitting elements 110 according to the mutual light-mixing effect generated between the light of adjacent light-emitting elements 110, and can also avoid the interval between adjacent light-emitting elements 110 being too large. Due to the uneven brightness distribution, the visual taste has obvious bright and dark blocks, that is, hot spots, or a bright line (Bright Line) is observed from a large viewing angle.

Moreover, in the embodiment illustrated in Figures 2A through 2C, the projection of the first boundary 213 and the projection of the second boundary 214 substantially overlap. In other words, the horizontal distance between the second boundary 214 and the light incident end surface 310 is substantially equal to the horizontal distance between the first boundary 213 and the light incident end surface 310, but is not limited thereto. The first boundary 213 and the second boundary 214 intersecting the light incident portion 300 and the light guide plate 200 may adjust the first boundary 213 according to the distance between the light emitting element 110 and the bent light incident portion 300, the height of the light emitting element 110, or other conditions. And the location of the second boundary 214.

In the embodiment shown in the upper view of FIG. 3A and the cross-sectional view of FIG. 3B, the first boundary 213 is closer to the light incident end face 310 than the second boundary 214. In other words, the horizontal distance between the first boundary 213 and the light incident end surface 310 is smaller than the horizontal distance between the second boundary 214 and the light incident end surface 310. The difference between the embodiment shown in FIGS. 3A and 3B and the backlight module of FIGS. 2A to 2C is only the relative relationship between the first boundary 213, the second boundary 214, and the light incident end surface 310. In addition, the structure and the use elements of the backlight module 100 of the two embodiments are substantially equal, and thus are not described herein.

The upper view of FIG. 4A and the cross-sectional view of FIG. 4B are different embodiments of the backlight module 100 shown in FIGS. 2A to 2C, wherein FIG. 4B is a side view of the light guide plate 200 from the side where the light-emitting element 110 is disposed. In the embodiment shown in FIG. 4A and FIG. 4B, the width of the second guiding slope 330 is substantially equal to the width of the light-emitting element 110, but is not limited thereto, so that the portion between the adjacent second guiding slopes 330 is partially separated. The bottom surface 212 of the light guide plate 200 is spaced apart. In other words, the second guiding slopes 330 are distributed in a spaced manner along the bottom edge 310b of the light incident end surface 310. The spacing of the second guiding slopes 330 is used to adjust the surface of the light guide plate 200 and the traveling path of the light, and thereby adjust the overall uniform brightness of the backlight module 100 of the embodiment and reduce the visibility. The bright line effect on the edge of the area.

In the embodiment of FIG. 4A and FIG. 4B, only the light generated by the partial light-emitting element 110 will travel in the total reflection manner in the light guide plate 200 after contacting the second guiding slope 330, and finally be the bottom surface 212 of the light guide plate 200. The microstructure is destroyed and the light is emitted from the light exit surface 211. As such, the backlight module 100 of the present embodiment can increase the uniformity of the front view brightness of the backlight module 100 near the first guiding slope position 320 by the structure shown in FIGS. 4A and 4B. In addition, the backlight module 100 of the present embodiment is substantially equal to the backlight module 100 shown in FIGS. 2A to 2C except for the feature that the second guiding slopes 330 are distributed in a spaced manner. Therefore, no further description is provided herein. In addition, the gap between the second guiding slope 330 and the reflecting plate 500 shown in FIG. 2B gives the backlight module 100 more space to set a space of components such as the light emitting element 110. In this way, the gap can compensate for the tolerance of the size of the component used by the backlight module 100 and thus save the time required for assembly of the backlight module 100.

5A, 5B and 5C show a modified embodiment of the backlight module 100 shown in Figs. 4A and 4B, wherein Fig. 5B is a cross-sectional view taken according to BB' of Fig. 5A. Please refer to FIGS. 5A to 5C at the same time. In this embodiment, the backlight module 100 further includes a plurality of auxiliary guiding slopes 333 formed between adjacent second guiding slopes 330 for guiding more light to travel in the light guide plate 200 in a total reflection manner. One end of the auxiliary guiding ramp 333 intersects the bottom surface 212 of the body 210 at the second boundary 214.

As shown in FIG. 5B, the auxiliary guiding slope 333 is inclined from the second boundary 214 toward the first guiding slope 320. In addition, the acute angle between the auxiliary guiding slope 333 and the bottom surface 212 toward the extension line of the light-incident end surface 310 is an auxiliary angle θ _A , which is smaller than the second guiding slope 330 and the bottom surface 212 facing the light-incident end surface 310 as shown in FIG. 2B . The second angle θ ₂ sandwiched by the extension line. The auxiliary guiding slope 333 can also reflect the light from the first guiding slope 320 and increase the incident angle of the large-angle incident light contacting the light-emitting surface 211 by the auxiliary angle θ _A . At that time, more light can be reflected by the light exit surface 211 and remain transmitted to the body 210 in a totally reflective manner.

FIG. 6A is a top view and FIG. 6B is a cross-sectional view showing another variation of the backlight module 100 shown in FIGS. 4A and 4B. In this embodiment, the second guiding slope 330 is parallel to the width of the light incident end surface 310 from the bottom edge of the light incident end surface 310 toward the second boundary 214 or the bottom surface 212 of the light guide plate 200. As shown in FIG. 6A, the second guiding slope 330 generates a radial opening in the direction of the light guide plate 200 from one end of the light incident end surface 310, wherein the radial opening corresponds to the light generated by the light source 120 of the light emitting element 110. The opening angle of the type. The backlight module 100 of the present invention will guide the light guide plate 200 to more light generated by the light-emitting elements 110 and simultaneously guide the light rays to the light guide plate 200 in a total reflection manner by the corresponding relationship between the openings and the light patterns. Travel inside. In other words, the opening of the radiation type can reduce the degree of light emitted from the first guiding slope 320 or the light guide plate 200 near the first guiding slope 320 and thereby improve the uniformity of the front view brightness of the backlight module 100 as a whole.

In the embodiment shown in FIG. 6A and FIG. 6B, each of the second guiding slopes 330 has the same width increasing rate in the direction of the bottom edge 310b of the light incident end surface 310 toward the second boundary 214, but is not limited thereto. In the embodiment shown in FIG. 7A and FIG. 7B, the width increase rate of the second guiding slope 330 near the side of the light incident end surface 310 is preferably smaller than the width of the second guiding slope 330 near the center of the light incident end surface 310. Increase rate. Thereby, the radial opening formed by the second guiding slope 330 near the side of the light incident end surface 310 allows more light to be emitted from the light emitting surface 211 of the body 210. Therefore, the backlight module 100 of the present embodiment has a lower brightness enhancement rate at a portion closer to the light incident end surface 310 than the intermediate portion, which can reduce the problem of edge bright lines in the visible region. As can be seen from the embodiment of FIG. 6A to FIG. 7B, the backlight module 100 of the present invention can adjust the brightness of the edge of the second guiding slope 330 and the uniform brightness of the whole by adjusting the width increase rate of the second guiding slope 330.

8A and 8B are top and cross-sectional views showing another embodiment of the backlight module 100 of the present invention. In the present embodiment, the second guiding slope 330 is a substantially discontinuous surface, wherein the second guiding slope 330 reflects light having different incident angles by using planes of different inclinations, and thereby The more light can enter the body 210 of the light guide plate 200 in a total reflection manner after passing through the second guiding slope 330.

As shown in FIG. 8A and FIG. 8B, the second guiding slope 330 of the embodiment includes a first sub-slope 331 and a second sub-slope 332. One end of the first sub-bevel 331 and one end of the second sub-bevel 332 are respectively connected to the bottom surface of the light-incident end surface 310 and the second boundary 214, wherein the first sub-slope 331 and the second sub-slope 332 are connected to form a third boundary. 215. In addition, the acute angle between the first sub-bevel 331 and the bottom surface 212 facing the extension line of the light-incident end surface 310 is a third angle θ ₃ and the second sub-bevel 332 and the bottom surface 212 and the bottom surface 212 of the body 210 face the optical end surface 310. The acute angle between the extension lines is a fourth angle θ ₄ , wherein the third angle θ ₃ is greater than the fourth angle θ ₄ .

In the embodiment shown in FIG. 8B, since the third angle θ _{3 is} greater than the fourth angle θ ₄ , the second guiding slope 330 of the embodiment has a slope greater than that of the second guiding slope 330 shown in FIG. 4 . The second guiding slope 330 can increase the incident angle of the light B contacting the light emitting surface 211 by changing the traveling direction of the light B. Therefore, the light B can be kept in the total reflection manner in the light guide plate 200 because the incident angle is greater than the critical angle, and finally exits the light guide plate 200 from the light exit surface 211 after being damaged by the microstructure of the bottom surface of the light guide plate 200. sold out. It can be seen that the backlight module 100 of the embodiment reduces the possibility of light exiting from the edge of the light guide plate 200 and thus increases the front view brightness of the light exit surface 211.

In addition, in the embodiment shown in FIG. 8A and FIG. 8B, the horizontal distance between the third boundary 215 and the light incident end surface 310 is preferably smaller than the distance between the first boundary 213 and the light incident end surface 310. In other words, the third boundary 215 is closer to the light incident end face 310 than the first boundary 213, but is not limited thereto. In different embodiments, the backlight module 100 of the present invention can also change the positions of the first boundary 213 and the third boundary 215 according to the position of the light source 120 of the light-emitting element 110 with respect to the light-incident end surface 310 to adjust the light contact first. The angle of the guiding slope 320 and the second guiding slope 330 and the position of the final light exiting.

9A and 9B show a modified embodiment of the backlight module 100 shown in FIGS. 8A and 8B. In this embodiment, the distance between the third boundary 215 and the light incident end surface 310 is substantially equal to the distance between the first boundary 213 and the light incident end surface 310, but is not limited thereto; in different embodiments, the backlight module 100 The position of the first boundary 213 or the third boundary 215 may also be adjusted such that the horizontal distance between the first boundary 213 and the light incident end surface 310 is smaller than the horizontal distance between the third boundary 215 and the light incident end surface 310. The backlight module 100 of FIG. 9A and FIG. 9B has substantially the same structure and the components used in the backlight module 100 as shown in FIGS. 8A and 8B except for the distance between the borders 213 and 215 and the light incident end surface 310. I will not repeat them here.

In addition, in the embodiment shown in FIG. 8A and FIG. 8B, the third angle θ ₃ is greater than the fourth angle θ ₄ , but is not limited thereto; in the embodiment shown in FIG. 10 or other different embodiments, The backlight module 100 of the invention can adjust the first sub-slope 331 and the second sub-slope according to the relative position between the light source 120 and the light-incident end surface 310, the ratio of the height between the light source 120 and the light-incident end surface 310, or other design requirements. The inclination of 332 causes the third angle θ _{3 to be} smaller than the fourth angle θ ₄ .

FIG. 11 is a diagram showing the percentage of light flux of the light guide plate and the percentage of light flux in the hot spot region which are presented in different embodiments of the backlight module 100 of the present invention. In FIG. 11, D1 and E1 respectively represent the luminous flux percentage of the light guide plate of the backlight module 100 shown in FIG. 1A and FIG. 1B and the percentage of the luminous flux in the hot spot area. D2 and E2 represent the percentage of the luminous flux of the light guide plate of the backlight module 100 shown in FIGS. 2A-C and the percentage of the luminous flux of the hot spot. D3 and E3 are shown as the percentage of the luminous flux of the light guide plate of the backlight module 100 shown in FIGS. 4A-B and the percentage of the luminous flux of the hot spot. D4 and E4 are shown as the percentage of the luminous flux of the light guide plate of the backlight module 100 shown in FIGS. 8A-B and the percentage of the luminous flux of the hot spot. D5 and E5 are shown as the percentage of the luminous flux of the light guide plate of the backlight module 100 shown in FIG. 10 and the percentage of the luminous flux of the hot spot. The light flux percentage of the light guide plate is the front view brightness that the backlight module 100 can be observed by the human eye, and the percentage of the light flux in the hot spot area is the brightness of the hot spot or the large view bright line that can be observed by the human eye.

As shown in FIG. 11, the backlight module 100 presented in the plurality of embodiments of the present invention has a lower luminous flux than the conventional backlight module shown in FIGS. 1A and 1B. However, the light flux of the hot spot area of the backlight module 100 of the present invention is much lower than that of the conventional hot spot area of the backlight module. In other words, the brightness of the hot spot generated by the backlight module 100 of the present invention is lower, and thus is less obvious to the viewer's human eye. Therefore, the present invention adjusts the first guiding inclined surface and the second guiding inclined surface of the bending light incident portion to compensate the incident angle of the light generated by the light source and the light emitting surface, thereby adjusting the overall brightness uniformity of the backlight module 100 and The brightness effect of the edge of the visible area.

While the foregoing description of the preferred embodiments of the invention, the embodiments of the invention The spirit and scope of the principles of the invention. Modifications of the various forms, structures, arrangements, ratios, materials, components and components may be employed by those skilled in the art. Therefore, the embodiments disclosed herein are to be considered as illustrative and not restrictive. The scope of the present invention is defined by the scope of the appended claims, and the legal equivalents thereof are not limited to the foregoing description.

100. . . Backlight module

110. . . Light-emitting element

120. . . light source

121. . . Light source center

130. . . Light bar

200. . . Light guide

210. . . Ontology

211. . . Glossy surface

212. . . Bottom

213. . . First boundary

214. . . Second boundary

215. . . Third boundary

300. . . Bending into the light department

310. . . Light entrance end

310a. . . Entrance end

310b. . . Bottom edge

310c. . . Top edge

320. . . First guiding slope

330. . . Second guiding slope

331. . . First sub-bevel

332. . . Second sub-bevel

333. . . Auxiliary guiding bevel

500. . . Reflective plate

A. . . Light

θ ₁ . . . First angle

θ ₂ . . . Second angle

θ ₃ . . . Third angle

θ ₄ . . . Fourth angle

θ _A . . . Auxiliary angle

1A is a top view of a conventional edge-lit backlight module;

1B is a cross-sectional view of the conventional edge-lit backlight module shown in FIG. 1A;

2A is a top view of the backlight module of the present invention;

2B is a cross-sectional view of the backlight module shown in FIG. 2A;

2C is a side view of the backlight module shown in FIG. 2A;

3A and 3B show a modified embodiment of the backlight module shown in FIGS. 2A-C;

4A and 4B show a modified embodiment of the backlight module shown in FIG. 2B;

5A, 5B, and 5C are another embodiment of the backlight module of the present invention;

FIG. 6A is a top view of a modified embodiment of the backlight module of the present invention; FIG.

6B is a side view of the backlight module shown in FIG. 6A;

7A is a top view of another embodiment of the backlight module of the present invention;

7B is a side view of the backlight module shown in FIG. 7A;

8A is a top view of another embodiment of the backlight module of the present invention;

8B is a cross-sectional view of the backlight module shown in FIG. 8A;

FIG. 9A is a modified embodiment of the backlight module shown in FIG. 8A;

9B is a cross-sectional view of the backlight module shown in FIG. 9A;

Figure 10 is a modified embodiment of the backlight module shown in Figure 8A;

FIG. 11 is a view showing a percentage of a light flux of a light guide plate and a percentage of a light flux of a hot spot in a backlight module according to different embodiments of the present invention.

100. . . Backlight module

110. . . Light-emitting element

120. . . light source

121. . . Light source center

130. . . Light bar

200. . . Light guide

210. . . Ontology

211. . . Glossy surface

212. . . Bottom

213. . . First boundary

214. . . Second boundary

300. . . Bending into the light department

310. . . Light entrance end

310a. . . Entrance end

310b. . . Bottom edge

310c. . . Top edge

320. . . First guiding slope

330. . . Second guiding slope

500. . . Reflective plate

A. . . Light

θ ₁ . . . First angle

θ ₂ . . . Second angle

Claims (34)

A light guide plate for use in a backlight module, comprising: a light emitting surface; a bottom surface opposite to the light emitting surface; an light incident end surface disposed on the light emitting surface and one side of the bottom surface, and extending across the light emitting a direction of the surface and the bottom surface; a first guiding slope, one end intersecting the light emitting surface at a first boundary, and the other end is connected to a top edge of the light incident end surface; wherein the first guiding slope is from the first a boundary extending toward the light exiting surface; and a second guiding slope opposite to the first guiding slope, the one end of the second guiding slope intersecting the bottom surface at a second boundary, and the other end Connecting the bottom edge of the light incident end surface; wherein the second guiding slope is inclined from the second boundary toward the first guiding slope, and the horizontal distance between the second boundary and the light incident end surface is not less than the first a horizontal distance between the boundary and the light incident end surface; the second guiding slope includes: a first sub-bevel, one end is connected to the light-incident end surface; wherein the first sub-slope and the bottom surface extend toward the light-incident end surface The sharp angle of the line is a third angle And a second sub-bevel, one end is connected to the second boundary, and the other end is connected to the first sub-slope to a third boundary; wherein the second sub-slope and the bottom surface are opposite to the extension line of the light-incident end surface The acute angle is a fourth angle, which is different from the third angle. The light guide plate of claim 1, wherein an acute angle between the first guiding slope and an extension line of the light-emitting surface toward the light-incident end surface is a first angle, and the second guiding slope and the bottom surface The acute angle of the extension line of the light incident end face is a second An angle; the first angle is greater than the second angle. The light guide plate of claim 1, wherein the third angle is greater than the fourth angle. The light guide plate of claim 3, wherein a horizontal distance between the third boundary and the light incident end face is not greater than a distance between the first boundary and the light incident end face. The light guide plate of claim 1, wherein the third angle is smaller than the fourth angle. The light guide plate of claim 5, wherein a distance between the third boundary and the light incident end face is not less than a distance between the first boundary and the light incident end face. The light guide plate of claim 1, further comprising a plurality of the second guiding slopes; wherein the plurality of second guiding slopes are spaced apart along a bottom edge of the light incident end surface. The light guide plate of claim 7, further comprising at least one auxiliary guiding slope disposed between the adjacent second guiding slopes; one end of the auxiliary guiding slope intersecting the bottom surface at the second boundary, and the other end And connecting the bottom edge of the light incident end surface; the auxiliary guiding slope is inclined from the second boundary toward the first guiding slope; wherein the auxiliary guiding slope and the bottom surface extend toward the light incident end surface The acute angle of the clip is smaller than the second angle of the second guiding slope and the extension of the bottom surface toward the light incident end surface. The light guide plate of claim 7, wherein at least a portion of the second guiding slope is parallel to the width of the light incident end surface from the bottom edge of the light incident end surface toward the second boundary. The light guide plate of claim 9, wherein the second guiding slope adjacent to the side of the light incident end face has a smaller width increase rate than the second guiding slope adjacent to the middle of the light incident end face. A backlight module comprising: the light guide plate according to claim 1; and at least one light source disposed corresponding to the light incident end surface; wherein the light source has a light source The vertical projection of the surface of the light source on the plane of the light incident end surface is covered by the light incident end surface. The backlight module of claim 11, wherein the first guiding inclined surface and the acute angle of the light emitting surface toward the extending end of the light incident end face are at a first angle, the second guiding inclined surface and the bottom surface The acute angle sandwiched by the extension line of the light incident end face is a second angle; the first angle is greater than the second angle. The backlight module of claim 11, wherein the second guiding slope comprises: a first sub-bevel, one end of which is connected to the light-incident end surface; wherein the first sub-slope and the bottom surface face the light-incident end surface The acute angle of the extension line is a third angle; and a second sub-bevel, one end is connected to the second boundary, and the other end is connected to the first sub-slope to a third boundary; wherein the second sub-bevel The acute angle between the bottom surface and the extension line of the light incident end surface is a fourth angle, and the fourth angle is different from the third angle. The backlight module of claim 13, wherein the third angle is greater than the fourth angle. The backlight module of claim 14, wherein a horizontal distance between the third boundary and the light incident end surface is not greater than a horizontal distance between the first boundary and the light incident end surface. The backlight module of claim 13, wherein the third angle is smaller than the fourth angle. The backlight module of claim 16, wherein a horizontal distance between the third boundary and the light incident end surface is not less than a horizontal distance between the first boundary and the light incident end surface. The backlight module of claim 11, wherein the light guide plate comprises a plurality of the second guiding slopes spaced along a bottom edge of the light incident end surface; each of the second guiding slopes is Relative to each of the light sources. The backlight module of claim 18, further comprising at least one auxiliary guiding slope disposed between the adjacent second guiding slopes; one end of the auxiliary guiding slope intersecting the bottom surface at the second boundary, and One end is connected to a bottom edge of the light incident end surface; the auxiliary guiding slope is inclined from the second boundary toward the first guiding slope; wherein the auxiliary guiding slope and the bottom surface extend toward the light incident end surface The acute angle of the line is smaller than the second angle of the second guiding inclined surface and the extending line of the bottom surface toward the light incident end surface. The backlight module of claim 18, wherein at least a portion of the second guiding slope is parallel to the width of the light incident end surface from the bottom edge of the light incident end surface toward the second boundary, the second guiding slope The width increase rate corresponds to the optical opening angle of the light source in the light guide plate. The backlight module of claim 20, wherein the second guiding slope adjacent to the side of the light incident end face has a smaller width increase rate than the second guiding slope adjacent to the middle of the light incident end face. The backlight module of claim 11, wherein a height of a center of the surface of the light source is lower than a height of a center of the light incident end surface. The backlight module of claim 11, wherein a height of a bottom edge of the surface of the light source is higher than a bottom edge of the light incident end surface. The backlight module of claim 11, wherein a height of a top edge of the surface of the light source is lower than a top edge of the light incident end surface. A light guide plate for use in a backlight module, comprising: a body having a light emitting surface and a bottom surface opposite to the light emitting surface; and a bent light incident portion extending from a side of the body, and Back to the bottom The bending light entering portion includes: a light incident end surface formed on one side surface of the bent light incident portion opposite to the body; a first guiding inclined surface, one end intersecting the light emitting surface a first boundary, the other end is connected to the top edge of the light incident end face; and a second guiding bevel is opposite to the first guiding bevel, and one end of the second guiding bevel intersects the bottom surface a second boundary, the other end is connected to the bottom edge of the light incident end surface; wherein the distance between the second boundary and the light incident end surface is not less than the distance between the first boundary and the light incident end surface; the second guiding slope includes: a first sub-bevel is connected to the light-incident end surface at one end; wherein an acute angle between the first sub-slope and the bottom surface of the light-incident end surface is a third angle; and a second sub-slope, one end Connected to the second boundary, the other end is connected to the first sub-slope to a third boundary; wherein the second sub-bevel and the acute angle of the bottom surface toward the extension line of the light-incident end face are a fourth angle The fourth angle is different from the third angle. The light guide plate of claim 25, wherein the acute angle between the first guiding slope and the extension of the light-emitting surface toward the light-incident end surface is a first angle, the second guiding slope and the bottom surface The acute angle of the extension line of the light incident end face is a second angle; the first angle is greater than the second angle. The light guide plate of claim 25, wherein the third angle is greater than the fourth angle. The light guide plate of claim 27, wherein a horizontal distance between the third boundary and the light incident end face is not greater than a horizontal distance between the first boundary and the light incident end face. The light guide plate of claim 25, wherein the third angle is smaller than the fourth angle. The light guide plate of claim 29, wherein a horizontal distance between the third boundary and the light incident end face is not less than a horizontal distance between the first boundary and the light incident end face. The light guide plate of claim 25, further comprising a plurality of the second guiding slopes; wherein the plurality of second guiding slopes are spaced apart along a bottom edge of the light incident end surface. The light guide plate of claim 31, further comprising at least one auxiliary guiding slope disposed between the adjacent second guiding slopes; one end of the auxiliary guiding slope intersecting the bottom surface at the second boundary, and the other end And connecting the bottom edge of the light incident end surface; the auxiliary guiding slope is inclined from the second boundary toward the first guiding slope; wherein the auxiliary guiding slope and the bottom surface extend toward the light incident end surface The acute angle of the clip is smaller than the second angle of the second guiding slope and the extension of the bottom surface toward the light incident end surface. The light guide plate of claim 31, wherein at least a portion of the second guiding slope is parallel to the width of the light incident end surface from the bottom edge of the light incident end surface toward the second boundary. The light guide plate of claim 33, wherein the second guiding slope adjacent to the side of the light incident end face has a smaller width increase rate than the second guide slope adjacent to the middle of the light incident end face.