TW201017243A - Light guide plate, backlight module and liquid crystal display device - Google Patents

Abstract

A light guide plate having a light-exiting surface, a bottom surface, a light-incident surface, and a light-reflecting surface is provided. The light-exiting surface is opposite to the bottom surface. The light-exiting surface, the bottom surface, the light-incident surface, and the light-reflecting surface are connected together. The light-reflecting surface has a light-reflecting structure disposed thereon. The light guide plate applied to a backlight module improves the luminance uniformity of the backlight module. A liquid crystal display device using the same has good display quality.

Description

201017243 ... a dMZITW 24345twf_d〇C/n IX. Description of the Invention: [Technical Field] The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device, a backlight module thereof and a light guide plate. [Prior Art] The liquid crystal display device can be roughly divided into two components: a liquid crystal display panel and a backlight module φ group, wherein the backlight module is used to provide sufficient brightness, and the liquid crystal display panel can display images. 1A is a top view of a conventional backlight module, and FIGS. 1B and 1C are schematic views respectively showing a light guide plate of different types of v-shaped grooves in the backlight module of FIG. Referring to FIG. 1A, iB & 1C, in order to improve the luminance performance of the backlight module 100, a light guide plate 110 or 110 having a V-shaped groove or a V-cut is generally used. The V-shaped groove of the light guide plate 11 () is located on the light-emitting surface thereof, and the V-shaped groove of the light guide plate 110' is located on the bottom surface thereof. Since the light guide plates 110, 110' having the V-shaped grooves can concentrate the light to improve the utilization of the light source, the backlight module 100 can have a good luminance. It should be noted that the direction of the grooves of the light guide plates 110 and 110 of the V-shaped groove and the direction of the lamp tube 120 in the backlight module 100 are perpendicular to each other, as shown in FIGS. 1B and 1C. When the incident light enters the light guide plate 11 of the v-shaped groove on the light-emitting surface, the light will be reflected through the mesh point (not shown) on the bottom surface of the light guide plate 110, and the light is reflected and refracted by the V-shaped groove. The positive ray path is shown in Figure 1B. For the light guide plate V1〇 of the V-shaped groove on the bottom surface, MZ1TW 24345twf.doc/n 201017243, as shown in FIG. 1C, the light will be totally reflected through the ¥-shaped groove located on the bottom surface of the light guide plate 11〇, The light path is directed directly above, and the backlight module 10() is discharged by the dot 112' above the light guide plate 110'. Therefore, whether the V-shaped groove is above the light guide plate = the design of the two matching dots to control the brightness of the backlight module and the visual taste of the display 0, in the conventional backlight module 100, because the light guide plates 11〇, 11〇 The reflected light 'is easy to concentrate the light in the central portion of the backlight module 100, especially when the V-shaped groove direction is opposite to the 2G square (four) light guide plate 11 or 110' of the lamp, in the backlight module 100 t, The two sides perpendicular to the direction of the lamp 12 会有 will have the formation of the dark area A as shown in FIG. 1A, commonly known as the waist. Φ Figure 1D is a schematic diagram of the party degree distribution of the lamp officer. Please refer to the figure and Fig. 1D. Since both ends of the lamp & 12G are the electrode terminals, the brightness of the light is lower than that of the lamp 12: the center is low. Therefore, in the lower corner of the backlight module 1 也, the dark area B is also formed, which is commonly called a vignetting angle. In this way, the problem of the degree of freedom of the backlight module will affect the display quality of the liquid crystal display device, and affect the visual taste and comfort of the viewer during viewing. [Summary of the Invention] A light guide capable of providing a uniform brightness of a backlight module. The invention provides a backlight module with uniform brightness. The present invention provides a liquid crystal display device with good display quality. The present invention provides a light guide plate having a light emitting surface. , a bottom surface, 6 201017243 χ v / / u

MZ1TW 24345twf.doc/n - Into the light side and - reflective side. The light-emitting surface is opposite to the bottom surface, and the reflective side surface, the light-incident side surface, the light-emitting surface and the bottom surface are connected to each other, and a light reflecting structure is disposed on the light-emitting surface. In an embodiment of the invention, the light reflecting structure described above is concentrated on the reflective side adjacent to the light incident side. In an embodiment of the invention, the light reflecting structure described above is interspersed on the reflective side.

In one embodiment of the invention, a brightness enhancement material is provided. In one embodiment of the invention, the material or phosphor material is emitted. In one embodiment of the invention, the recess is a hole. The above-mentioned light-reflecting structure is further coated with the above-mentioned brightness-enhancing material, which comprises a plurality of light-reflecting structures, which are opposite to each other. In one embodiment of the invention, the light-guiding plate has a plurality of V-shaped grooves on the bottom surface.

In an embodiment of the invention, the light guide plate further has a plurality of V-shaped grooves on the light-emitting surface. The present invention provides a backlight module 'which includes a frame, a light source, and a light guide plate as described above. The light source is disposed in the frame, and the light incident side of the light guide plate faces the light source. In an embodiment of the invention, the light source is a cold cathode fluorescent lamp. In an embodiment of the invention, the two edge regions of the cold cathode fluorescent lamp described above are not coated with a phosphor material. In an embodiment of the invention, the wall of the cold cathode fluorescent lamp, MZ1TW 24345twf.doc/n 201017243, is coated with a fluorescent material and the luminescent material is concentrated in the two edge regions of the cold cathode fluorescent lamp. In an embodiment of the invention, the light source is a light emitting diode. The invention provides a liquid crystal display device which includes a liquid crystal display panel and a backlight module as described above, wherein the backlight module is disposed under the liquid crystal display panel and the light emitting surface of the light guide plate of the backlight module faces the liquid crystal display panel. In an embodiment of the invention, the liquid crystal display device further includes an optical film disposed between the backlight module and the liquid crystal display panel. In an embodiment of the invention, the optical film described above comprises a brightness enhancement sheet, a enamel sheet or a diffusion sheet. The invention arranges a light reflecting structure on the reflective side of the light guide plate to improve the dark area brightness of the conventional backlight module by using the light reflecting structure. Therefore, the backlight module using the light guide plate of the present invention has a uniform thickness, thereby improving the display quality of the liquid crystal display device. The above described features and advantages of the present invention will become more apparent from the following description. 2 is a schematic diagram of a liquid crystal display device according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a backlight module disposed on the liquid crystal display I of FIG. 2, and FIG. 4 is a light source and a guide of the backing group of FIG. Schematic diagram of the system. Please refer to FIG. 2, FIG. 3 and FIG. 4 at the same time. The liquid crystal display device surface includes a liquid crystal display panel 600 and a backlight module $(8) disposed under the liquid crystal display panel 6. The backlight module 50A includes a frame 400, a light source 300, a reflection sheet 7〇〇8 201017243mZ1TW 24345twf.doc/n, and a light guide plate 200. The light source 300 is disposed in the frame 400. The light source 300 of the embodiment is a cold cathode luminescent lamp (CCFL). The frame 400 shown in Fig. 3 is a lamp reflector which covers the light source 300' to reflect the light emitted from the light source 300 to avoid light leakage. A portion of the light guide plate 200 bears against the frame 4 , and the light guide plate 200 is located beside the light source 300 . The reflection sheet 700 is disposed under the light guide plate 2 . Generally, the light emitted by the light source 300 is emitted through the guide of the light guide plate 2, so that the backlight module 500 can provide brightness to the liquid crystal display panel 6 to display an image. In detail, the light guide plate 200 has a light emitting surface 210, a bottom surface 220, a light incident side surface 230, and a reflective side surface 240. The light exiting surface 210 faces the liquid crystal display panel 600' and opposes the bottom surface 220, and the reflective sheet 700 is located below the bottom surface 220. Further, the light-emitting surface 210, the bottom surface 220, the light-incident side surface 230, and the light-reflecting side surface 240 are connected to each other. The light-incident side 230 faces the light source 300' and the light emitted by the light source 300 will partially enter the light guide plate 200' from the light-incident side surface 23, and the portion will first be reflected to the frame 4, and then reflected. The side surface 230 enters the light guide plate 200. The light path of the light entering the light guide plate 200 is guided and is emitted from the light-emitting surface 210 outside the light guide plate 200, and part of the light is reflected by the reflection sheet 700 and then emitted through the light-emitting surface 21 to exit the light guide plate. 2 〇〇 outside. In particular, the light source 300 of the present embodiment is a cold cathode fluorescent lamp comprising a bulb 310, mercury gas (not shown), and a phosphor material 320 coated in the tube wall of the bulb 310. However, since both ends 9 2 of the lamp tube 31 and the double _ TW 24345 twf.doc/n are the electrode terminals 330, when the cold cathode fluorescent lamp is assembled to the frame 4, the backlight module 500 corresponds to the lamp tube 310. At the electrode end 330, the luminance will be lower. In addition, since the conventional cold cathode fluorescent lamp is produced by sucking the fluorescent material 32 into the tube 310 and adhering to the tube wall of the bulb 310, a large amount of the fluorescent material 320 is adhered to the center of the tube 31. The phosphor material 320 near the edge region 330a of the electrode terminal 33A is relatively small, and may not be adsorbed to expose the transparent tube wall. Thus, the ultraviolet light generated by the excitation of the mercury gas molecules φ through the cold cathode fluorescent lamp cannot be absorbed by the fluorescent material in the edge region 33〇a to form visible light, so that the luminous efficiency is also relatively poor. Therefore, the brightness of the edge region 330a is dark, and there is even a concern that the ultraviolet light is emitted. The above problem may deteriorate the optical effect of the backlight module, which in turn affects the display quality of the liquid crystal display device. In other embodiments not shown, the light source 3 can also be a light bar formed by assembling a plurality of light emitting diodes (LEDs) on a substrate. Since the two sides of the light strip still need to be reserved for the position of the backlight module 500, the brightness of the backlight module 5 〇〇 corresponding to the light source 3 两端 at both ends is also low. In order to improve the luminance uniformity of the backlight module 500, the optical function of the light guide plate 2A can be more effectively exerted, and the light reflecting structure 250 is disposed on the reflective side surface 240. The light reflecting structure 250 can be a plurality of recessed holes. By means of the light reflecting structure 250, the path of the light incident on the reflective side 24〇 can be adjusted to improve the brightness uniformity of the backlight module. Fig. 5A is a view showing a light reflecting structure disposed on a reflecting side of the light guiding plate, and Fig. 5B is a view showing a light path changing light path by the light reflecting structure. Referring to FIG. 5A and FIG. 5B simultaneously, the light-reflecting structure 250 may be formed by forming a light guide plate 200 with the light guide plate 2. Alternatively, it may be that the light guide plate 2 is first fabricated and then processed on the reflective side surface 24 to form the light reflecting structure 250. As shown in FIG. 5B, when the light of the light source 300 enters the light guide plate 200 from the light incident side surface 230, the light incident on the light reflecting structure 250 of the reflective side 240 changes its light path and exits closer to the reflective side 240. It is possible to improve the conventional backlight module ❹ having a corner vignetting angle and a dark area on both sides perpendicular to the direction of the tube to form a waist. Therefore, by the light reflecting structure 25, the luminance uniformity of the backlight module 500 can be improved, and the display quality of the liquid crystal display device 1 can be improved. It is worth mentioning that the backlight assembly 500 mentioned above has a lower luminance at the assembly ends of the light source 300, so that the light reflection structure 250 can be concentrated on the reflective side 24 and adjacent to the light side 23〇. The place 'is shown in Figure 5A. Thus, the light can be emitted from the assembly closer to the ends of the light source 3A to increase the brightness of the backlight module 5 at the two ends of the light source 300. Therefore, the backlight module 5 can have a relatively uniform luminance. The distribution area of the light reflecting structure 250 described above may be obtained by calculation or simulation. For example, we can arrange a plurality of circular light reflecting structures 25 inconsistent in size for different requirements, and arrange them from the large and small reflective side 240, as shown in FIG. 5B and FIG. 6A. The light reflecting structure 250 may be arranged laterally in the longitudinal direction of the reflective side 240 as shown in Fig. 6B. 201017243 ΗνίΖ ITW 24345twf.doc/n Of course, the arrangement and shape of the light reflecting structure 250 are only used for exemplifying the embodiments, and are not intended to limit the present invention. Those skilled in the art will be able to arbitrarily change the shape and arrangement of the light reflecting structure 250 in response to different needs. For example, in order to achieve different optical effects of the light guide plate 2, the light reflecting structure 250 of the embodiment may be regularly or irregularly disposed on the reflective side surface 24A. Further, the light reflecting structure 250 may be disposed on the reflective side surface 240 in various shapes. It is worth mentioning that in order to improve the utilization of light, a brightness enhancement material 260 may be applied to the light reflecting structure 250 of the reflective side 240. In other words, the brightness enhancement material 260 is filled into the recessed holes. Filling the shell-degree reinforcing material 260 into the recess prevents the brightness-enhancing material 260 from peeling off due to inadvertent collision with the frame 4 when the light guide plate 200 is placed in the frame 400. The immunity enhancing material 260 can be a fluorescent material or a reflective material. If the shell enhancement material 260 is a reflective material, it will reflect the light and thereby increase the luminance of both sides of the moonlight module 500. If the brightness enhancement material 26 is a firefly, the material intensity enhancement material 260 can self-illuminate after receiving the light of the light source 300 to enhance the brightness of both sides of the backlight module 500. Specially, the 反射, by the light reflecting structure 250 and the brightness enhancement material!! The setting can improve the problem that the backlight module has a vignetting angle. If the fluorescent material 32 〇 of the lamp edge region 330a is unevenly coated or even coated, the fluorescent material 32 〇 can be applied to the fine concave hole of the reflective side to compensate the edge. Brightness. Therefore, the phosphor material can be selectively coated or uncoated at the edge region 330a of the lamp tube (10) near the electrode 12 201017243 uvlZlTW 24345 twf.doc/n end 330, depending on the demand. Alternatively, we may provide a plurality of V-shaped grooves 222 on the bottom surface 220. Thus, the brightness of the sides and corners of the backlight module 500 is more consistent with the brightness of the central portion, and the backlight module 500 thus has a relatively uniform brightness. Of course, those skilled in the art will be able to arbitrarily designate V-grooves on the light exit surface 210, depending on other known techniques. In summary, by arranging the light reflecting structure on the reflective side of the light guide plate, the light path can be changed, so that the light emitted from the light source can be preferably used. In addition, the light is also emitted outside the backlight module at the edges near the light source, so that the conventional backlight module can have problems of vignetting and waist. In addition, with the use of brightness enhancement materials, the backlight module can have a relatively uniform rotation degree. (4) The liquid crystal display device using the back button group can have good display quality. φ - although the invention has been described above in terms of preferred embodiments, it is not intended to limit the invention, and any one skilled in the art will be able to make some changes without departing from the spirit and scope of the invention. Retouching, = the definition of the application patent of the present invention, which is attached to the patent application. [Fig. 1A] is a schematic view of a conventional backlight module. Figure 1C shows the different types of the backlight module of Figure 1A. 13 201017243

iviZlTW 24345twf.doc/n Schematic diagram of the light guide plate of the v-shaped groove. Figure ID is a schematic diagram of the brightness distribution of the lamp. 2 is a schematic view of a liquid crystal display device according to an embodiment of the present invention. 3 is a schematic diagram of a backlight module of the liquid crystal display device of FIG. 2. 4 is a schematic view of a light source and a light guide plate of the backlight module of FIG. 3. Fig. 5A is a view showing a light reflecting structure provided on a reflecting side of the light guiding plate. FIG. 5B is a schematic diagram of light rays changing a light path by a light reflecting structure. Fig. 6A is a schematic view showing the arrangement of the light-reflecting structures from small to large on the reflective side. Figure 6B is a schematic illustration of another perspective view of the light reflecting structure aligned on the reflective side. [Main component symbol description] 100: backlight module 110, 110', 200: light guide plate 112': dot 120: lamp 210: light exit surface 220: bottom surface 222: V-shaped groove 230 = light-incident side 240: reflective side 250: light reflection structure 14 201017243 heart TW 24345twf.doc / n 260: brightness enhancement material 300: light source 310: lamp tube 320: fluorescent material 330: electrode end 330a: edge area 400: frame 500: backlight module 600 · liquid crystal Display Panel 700: Reflector 1000 ··Liquid Crystal Display Unit A, B: Dark Area 201017243 Heart TW 24345twf.doc/n

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Claims (1)

201017243^1TW 24345twf.doc/n X. Patent application: 1. A light guide plate having a light exit surface, a bottom surface, a light incident side surface and a reflective side surface, the light emitting surface being opposite to the bottom surface, and the reflective side surface The light incident side surface, the light exiting surface and the bottom surface are connected to each other, wherein a light reflecting structure is disposed on the reflective side surface. 2. The light guide plate of claim 1, wherein the light reflecting structure is concentrated on the reflective side adjacent to the light incident side. 3. The light guide plate of claim 2, wherein the light reflecting structure is interspersed on the reflective side. 4. The light guide plate of claim 1, wherein the light reflecting structure is further coated with a brightness enhancement material. 5. The light guide plate of claim 4, wherein the brightness enhancement material comprises a reflective material or a fluorescent material. 6. The light guide plate of claim 2, wherein the light reflecting structure is a plurality of recessed holes. 7. The light guide plate as described in claim 1 further has a plurality of V-shaped grooves located on the bottom surface. <The light guide plate' as described in claim 1 further has a plurality of V-shaped grooves on the light-emitting surface. A backlight module comprising: a frame; a light source 'disposed in the frame; and a light guide plate disposed in the frame, having a light emitting surface, a bottom surface, a light incident side and a reflective side surface, and The light incident side faces the light source, 16 201017243, the light emitting surface is opposite to the bottom surface, and the reflective side surface, the light incident side surface, the light emitting surface and the bottom surface are interconnected, wherein the reflective side surface is connected to the bottom surface Set a light reflection structure. 10. The backlight module of claim 9, wherein the light reflecting structure is concentrated on the reflective side adjacent to the light incident side. 11. The backlight module of claim 9, wherein the light reflecting structure is interspersed on the reflective side. 12. The backlight module of claim 9, wherein the light-reflecting structure is further coated with a brightness enhancement material. 13. The backlight module of claim 12, wherein the brightness enhancement material comprises a reflective material or a fluorescent material. 14. The backlight module of claim 9, wherein the light reflecting structure is a plurality of recessed holes. 15. The backlight module of claim 9, wherein the light guide plate further has a plurality of V-shaped grooves on the bottom surface. 16. The backlight module of claim 9, wherein the light guide plate further has a plurality of V-shaped grooves on the light-emitting surface. 17. The backlight module of claim 9, wherein the light source is a cold cathode fluorescent lamp. 18. The backlight module of claim 17, wherein the edge regions of the cold cathode fluorescent lamp are not coated with a fluorescent material. The backlight module of claim 17, wherein the tubular wall of the cold cathode fluorescent lamp is coated with a fluorescent material. 20. The backlight module of claim 9, wherein the light source is 17 24345 twf.doc/n 201017243 „iZ1TW light emitting diode. 21. A liquid crystal display device comprising: a liquid crystal display panel; a backlight The module is disposed under the liquid crystal display panel and includes: a frame; a light source disposed in the frame; and a light guide plate disposed in the frame having a light emitting surface, a bottom surface, a light incident side, and a Reflecting the side, and the light-incident side faces the light source, the light-emitting surface faces the liquid crystal display panel and faces the bottom surface, and the light-reflecting side surface, the light-incident side surface, the light-emitting surface and the bottom surface are connected to each other, wherein the light-reflecting surface The liquid crystal display device of claim 21, wherein the light reflecting structure is concentrated on the reflective side adjacent to the light incident side. In the liquid crystal display device, the light reflecting structure is disposed on the reflective side. 24. The liquid crystal display device according to claim 21, The light-reflecting structure is further coated with a brightness enhancement material. The liquid crystal display device of claim 24, wherein the brightness enhancement material comprises a reflective material or a fluorescent material. The liquid crystal display device of claim 21, wherein the light reflecting structure is a plurality of recessed holes. 27. The liquid crystal display device of claim 21, wherein the light guide plate further has a plurality of V-shaped grooves, 28. The liquid crystal display device according to claim 21, wherein the light guide plate further has a plurality of V-shaped grooves on the light-emitting surface. 29. The liquid crystal display device of claim 21, wherein the light source is a cold cathode fluorescent lamp. 30. The liquid crystal display device of claim 29, wherein the edge region of the cold cathode fluorescent button is not coated with firefly The liquid crystal display device according to claim 29, wherein the wall of the cold cathode glory lamp is coated with a glory material. 32. The liquid crystal display device is a light-emitting diode. The liquid crystal display device of claim 21, further comprising an optical film disposed between the backlight module and the liquid crystal display panel. 34. The liquid crystal display device of claim 5, wherein the optical film comprises a brightness enhancement sheet, a dome or a diffusion sheet. 19