TW201017288A - Backlight module and liquid crystal display device - Google Patents

Abstract

A backlight module includes a light guide plate and at least a light source. The light guide plate has a light-exiting surface, a bottom surface, at least a light-incident side surface and two light-reflecting side surfaces opposite to each other. The light-exiting surface is opposite to the bottom surface. The light-reflecting side surfaces, the light-incident side surface, the light-exiting surface and the bottom surface are connected together. Each of light-reflecting side surfaces has an optical adjusting structure. Each optical adjusting structure includes a plurality of grooves. Each of the grooves has a first slanted surface, a peak and a second slanted surface intersecting with the first slanted surface at the peak. In each of the grooves, a first side of the first slanted surface distant from the peak is at a first distance from a second side of the second slanted surface distant from the peak. The light sources are disposed on the side of the light-incident side surfaces.

Description

201017288 *-------MZ1TW 27357twf..doc/n IX. Description of the Invention: [Technical Field] The present invention relates to a backlight module and a liquid crystal display device And, in particular, a light guide plate suitable for use in a backlight module and a liquid crystal display device. [Prior Art] The β liquid crystal display device can be roughly divided into two components: a liquid crystal display panel and a backlight module, wherein the backlight module is used to provide sufficient brightness so that the liquid crystal display panel can display an image. 1 is a top view of a conventional backlight module, and FIGS. 1A and 1C are schematic views of a light guide plate using different types of v-shaped grooves for the backlight module of FIG. Please refer to FIG. 1A, 1], and lc at the same time. In order to improve the brightness performance of the backlight module 1, a light guide plate 1 or a light guide plate having a v-groove (v_gr〇〇ve or V-cut) is usually used. The v ❹ type groove of the light guide plate 1 位于 is located on the light emitting surface IGa, and the ▽ 槽 groove of the light guide plate 1 位于 is located at the bottom surface 10 b thereof, and has a light above and below the light guide plate 1 〇, 1 分别, respectively. The optical film 14 and a reflective sheet 16. Since the light guide plate 1? having the V-shaped groove and the light guide plate 10' can concentrate the light to enhance the light source utilization, the backlight module 1 can have a good luminance.

It should be noted that in order to make the overall uniformity of the light-emitting surface of the light guide plate better, the direction of the groove of the light guide plate 1 〇 and the light guide plate 1 of the V-shaped groove is the direction of the groove of the backlight module 1 The placement directions are perpendicular to each other as shown in Figures 1B and 1C 5 201017288MZ1TW 27357twf..doc/n. When the incident light enters the light guide plate i of the V-shaped groove on the light-emitting surface 10a, the light is reflected by the mesh point (not shown) of the bottom surface 10b of the light guide plate 10, and is refracted by the V-shaped groove. Light, and then a centralized management of the light path to increase the brightness of the front side, as shown in Figure 1B. For the light guide plate 10'' of the bottom surface of the v-shaped groove, as shown in FIG. 1C, the light is guided directly above the light path through the reflection sheet 16 under the bottom surface 10b' of the light guide plate 10', and then through the V-shaped groove. A centralized management of the light path is performed to increase the Φ front light exit brightness' and the light output of the backlight module 1 can be evenly distributed by the light guide plate 10 and the upper mesh point 12. Therefore, whether the v-shaped groove is above or below the light guide plate, the design of the dot must be matched to control the brightness of the backlight module and the visual taste of the display. In the conventional backlight module 1, since the light is reflected by the light guide plate 10 or the light guide plate 10', it is easy to concentrate the light in the central portion of the backlight module i, especially when the v-shaped groove direction and the light tube When the orientation direction of 20 is perpendicular, the light guide plate 10 or the light guide plate 1 〇 will have a shape of a dark area A as shown in FIG. 1A on both sides, which is commonly called a waistband dark band. In this way, the brightness of the backlight module i is uneven = the shadow of the liquid crystal display device f, the visual taste and comfort of the viewer when viewing the face. SUMMARY OF THE INVENTION The present invention provides a backlight module with uniform brightness. ^ Ming provides a liquid crystal display device with good display quality. - a backlight module comprising: a light guide plate and at least /, the V first plate has a light exit surface, a bottom surface, at least - a light incident side surface ivIZITW 27357twf .doc/n 201017288 and two opposite reflective sides . The light emitting surface is opposite to the bottom surface. The reflective side surface and the entrance surface are connected between the light exit surface and the bottom surface, wherein each - reflective side surface has: light: diameter adjustment structure. Each of the light path adjustment structures includes a plurality of grooves. The mother-groove has a first inclined surface, a ridge portion, and a second inclined surface which is first inclined to the peak portion, wherein each of the first inclined surface of the groove is away from the peak phase - the first end and the corresponding second inclined surface A second end away from the peak is spaced apart - the first distance. Recorded on the side of the human light. In one embodiment, the light guide plate has a -first-reference plane substantially perpendicular to the human light side and a first acute angle between the second sloped-first reference plane. In the embodiment of the invention, the first acute angle is 5.6 degrees. In the towel of the present material, the above-mentioned material is: the slope of the slope and the normal line and the light in the light guide plate are incident on the degree of Γ9〇, in the embodiment, the first incident angle of the above-mentioned Fan Yuanjie & In the embodiment, the above-mentioned optical path adjustment structure path μ敕!! is formed on the first reference plane, and the orthographic projection coincides with another light. The peaks of the structure form an orthographic projection on the second reference plane. In one embodiment of the first invention, one of the peaks described above is formed on one of the upper orthographic projections at a midpoint of the first distance. In one embodiment of the first invention, the length of the first bevel is greater than the length of the bevel. In an embodiment of the invention, the length of the second bevel is greater than 7 201017288 -------- MZ1TW 27357twf..doc/n the length of the first bevel. In an embodiment of the invention, the light source is a cold cathode lamp. In an embodiment of the invention, the light source is a light emitting diode. The invention provides a liquid crystal display device comprising a liquid crystal display panel and a backlight module. The backlight module is disposed under the liquid crystal display panel. The backlight module includes a light guide plate and at least one light source. The light guide plate has a light exiting φ surface, and the bottom surface has at least one light incident side and a opposite reflective side. The light emitting surface is opposite to the bottom surface. The reflective side and the light incident side are connected between the light emitting surface and the bottom surface. There is a light path adjustment structure on each reflective side. Each of the light path adjustment structures includes a plurality of grooves. Each of the trenches has a first beveled third peak and a second bevel that intersects the first bevel on the peak, wherein the first bevel of the parent trench is away from a first end of the peak and the corresponding first A second end of the slope away from the peak is at a first distance. The light source is placed next to the light entrance side. In an embodiment of the invention, the first slope is formed with a first reference plane I - the first acute angle H plane forms a second acute angle with the n test plane. The second reference plane is substantially perpendicular to the light incident side. The first reference plane is substantially perpendicular to the direction in which the second ramp extends. In an embodiment of the invention, the light guide plate further has a first reference plane. The first reference plane is substantially perpendicular to the light incident side, and a first acute angle is sandwiched between the second slope and the first reference plane. In an embodiment of the invention, the first acute angle is 5.6 degrees. In the embodiment of the present invention, the light guide plate has a method 8 201017288 --------- ΛΖΙΤ ν / 27357 twf.. doc / n line: and the normal line is perpendicular to the second slope, and the normal line A light incident path in the light guide plate sandwiches a first incident angle. In the embodiment of the invention, the first incident angle is in the range of 42.2 degrees to 90 degrees. In an embodiment of the present invention, the orthographic projection of the peak portion formed by one of the light path adjusting structures on the first reference plane coincides with the exaggeration of the other optical path adjusting structure formed on the first reference plane. Orthographic projection. In one embodiment of the invention, one of the peaks is formed such that one of the first distances is orthographically located at a midpoint of the first distance. In an embodiment of the invention, the length of the first inclined surface is greater than the length of the second inclined surface. In one embodiment of the invention, the length of the second ramp is greater than the length of the first ramp. In one embodiment of the invention, the light source is a cold cathode fluorescent lamp. In an embodiment of the invention, the light source is a light emitting diode. The present invention arranges a light path adjustment on the reflective side of the light guide plate to improve the dark area = brightness of the conventional backlight module by using the light path adjustment structure. Therefore, the backlight module using the light guide plate of the present invention has a uniform luminance, thereby improving the display quality of the liquid crystal display device. The above and other objects, features, and advantages of the present invention will become more apparent from [Embodiment] 9 ΛΖ 1TW 27357 twf. .doc/n 201017288 FIG. 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 of the liquid crystal display device of FIG. 2, and FIG. 4A is FIG. A schematic diagram of a light source and a light guide plate of the backlight module. Referring to FIG. 2, FIG. 3 and FIG. 4A, the liquid crystal display device 100 includes a liquid crystal display panel 200 and a backlight module 300. The backlight module 300 is disposed under the liquid crystal display panel 200. The backlight module 300 includes a light guide plate 400, at least one light source 500 (only one of which is schematically shown in FIG. 3), a reflective sheet 600_, and a frame 700. The light source 500 of the embodiment is a cold cathode fluorescent lamp (cold cathode). Fluorescence lamp, CCFL), can be used to provide light. In other embodiments not shown, the light source 500 may also be a light bar formed by assembling a plurality of light emitting diodes (LEDs) on a substrate. The frame 700 shown in FIG. 3 is a lamp reflector, which covers the light source 500 for reflecting the light emitted from the light source 500, thereby improving the utilization of the light source and avoiding light leakage. A portion of the light guide plate 400 bears against the frame 700, and the light guide plate 400 is positioned beside the light source 500. The reflection sheet 600 is disposed under the light guide plate 400. ❹ Generally, the light emitted by the light source 500 is emitted after being guided by the light guide plate 4', so that the backlight module 300 can provide brightness to display the image on the liquid crystal display panel 200. In detail, the light guide plate 400 has a light exiting surface 410, a bottom surface 420, at least one light incident side surface 430 (only one of which is schematically illustrated in Fig. 4A), and a two-phase opposite light reflecting side surface 440. The light-emitting surface 410 is opposite to the bottom surface 420, and the light-emitting surface 410 faces the liquid crystal display panel 200, and the reflective sheet 600 is located under the bottom surface 420. In addition, the reflective side surface 440 and the light incident side surface 430 are connected to the light emitting surface 410 and the bottom surface 420 by 201017288 ^ v/«wvx^x4Z1TW 27357twf..doc/n. The light incident side 430 faces the light source 500, and the light emitted by the light source 500 will partially enter the light guide plate 400' directly from the light incident side surface 430, and the portion will first be reflected to the frame 700 and then reflected, and then enter the light guide side 430. Light board 400. The light entering the light guide plate 400 is guided by the light-emitting surface 410 and is emitted from the light-emitting surface 400. The light is reflected by the reflective sheet 600 and then emitted through the light-emitting surface 410. Outside. 4B is a top plan view of the light source and the light guide plate of the backlight module of FIG. 4A. 4A and 4B, it is worth noting that by providing the light path adjusting structure 450 on the reflective side surface 440, since the light path adjusting structure 450 has a plurality of grooves 450a, the light path adjusting structure 450 can adjust the incident to The path of the light on the reflective side 440 improves the darkness of the conventional backlight module and has the problem of the waist, thereby improving the luminance uniformity of the backlight module. In detail, each of the two reflective side surfaces 440 of the embodiment is provided with an optical path adjustment structure 450, and each of the light path adjustment structures 450 includes a plurality of grooves 450a. Each trench 450a has a first bevel 452, a peak 454, and a second bevel 456 that intersects the first bevel 452 at the peak 454. In addition, a first end 452a of the first slope 452 of each trench 450a away from the front portion 454 is spaced apart from the first end 456a of the corresponding second slope 456 by a first distance dl away from the peak portion 454. In the present embodiment, the orthographic projection 45 of one of the crotch portions 454 formed on the first distance d1 is not located at the midpoint of the first distance di. In other words, the cross-sectional shape of each of the grooves 450a of the light path adjusting structure 450 11 201017288 ru / y D D D D D D D , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , That is, the length of the first slope 452 is not equal to the length of the second slope 465. Also in this embodiment, the length of the second slope 456 is greater than the length of the first slope 452. Of course, in other embodiments, the length of the first slope 452 may be greater than the length of the second slope 456. In addition, in other embodiments not shown, one of the peaks 454 is formed on the first distance dl. The second projection 454a may also be located at the midpoint of the first distance d1. That is, the groove 450a of the light path structure 450 may also be a v-shape with two slopes symmetric. Fig. 5A is a partially enlarged schematic view showing the light path adjusting structure of the light incident side surface and the light reflecting side surface of the light guide plate of the present invention. Referring to FIG. 4B and FIG. 5A simultaneously, in the embodiment, a first acute angle 0 is sandwiched between the second inclined surface 456 and a first reference plane ρι, wherein the first reference plane P1 is substantially perpendicular to the light incident side. 430, and the first acute angle 夹 between the second inclined surface 456 and a first reference plane P1 is, for example, 5.6. . The angle formed by the second inclined surface 456 of the trench 450a of the optical path adjusting structure 450 and the first reference plane pi is calculated by simulation, so that the light incident on the reflective side 440 can be totally reflected to make full use of the light. The light source and the purpose of improving the brightness uniformity of the backlight module. The design principle of the optical path adjusting structure 45A of the present invention will be described in detail below. The route of travel of light from one medium to another can be inferred from Snell's Law. Syner's law is a phenomenon that describes the refraction of light. In detail, when light is incident from one medium to another, since the different media have different refractive indices, the light in another medium will change its course of travel. The relationship between the isner's law is as follows: n^in Θ i = n2sin θ 2 , where 叱 and η2 are the refractive indices of the two media, 01 and ~ are the angles between the incident and refracted light and the interface normal, respectively. Also known as the angle of incidence and angle of refraction. In addition, the physical meaning of the 'total reflection phenomenon means that there is no refracted light at this time and only reflected light exists, and the total reflection phenomenon occurs when the refractive index η of the medium is larger than the refractive index 另一 of the other medium (ie, the medium where the incident light is located) The refractive index is higher than the refractive index of the medium where the refracted light is located. It is worth mentioning that, in this embodiment, the medium is air and light guide plate 400 respectively, wherein the refractive index η! of air is 1.0, and the material of the light guide plate 400 is exemplified by polymethyl methacrylate (ΡΜΜΑ). The refractive index η2 is 1.49, that is, the condition that the refractive index of the medium in which the incident light is located is higher than the refractive index of the medium in which the refracted light is located. In addition, the minimum incident angle 0 c at which total reflection occurs is called a critical angle. Therefore, when the incident angle is greater than the critical angle of 0C, the total reflection phenomenon will occur. In the embodiment, when the light traveling in the light guide plate 400 is coldly incident on the second inclined surface 456 at the first incident angle, and the total reflection phenomenon occurs, the refraction angle 0 1=9〇° at this time is determined by the relationship. For example, sin Θ c = ηι / η2 » Θ c = 42.2 °, so the condition that the total reflection occurs in this embodiment is that the incident angle /5 is greater than 42.2 °. On the light incident side surface 430, since the position of the light path adjusting structure 450 corresponds to both ends of the cold cathode fluorescent lamp, the angle of the light provided by the cold cathode fluorescent lamp entering the light path adjusting structure 450 is the second incident angle 0. And the refraction 13 201017288 ---------V1Z1TW 27357twf..doc/n angle is a, get θ ^sirT1!; (r^/n!) · sin a). Further, it is assumed that the angle at which the second slope 456 intersects the normal line of the light incident side surface 430 is r' from the inner angle sum of the triangle to 180. , you can know that a+yg + r-π, substituting 0=sin-i((n2/ni) · sina), and learning through the trigonometric function, 6> two sin_1 (such as / called) · sin (million + r )). The inner angle and relationship of the triangle formed by the normal line P2 of the first reference plane P1, the second slope 456 and the second slope 456 are ❹ Θ, +Ur ) +τγ/2=7γ, and this formula is substituted into 0 = sin-i( (η2/ηι) · sin(石+ γ )) gives <9 = sin, (η2/ηι) · cos (point + (9,)). Since the angle of incidence is defined as the angle between the incident light and the normal to the interface between the media, it must be less than 90. 'So 0 is less than 9〇. And 々 is less than 9〇. In order to achieve total reflection cold, the value must be greater than the critical angle 0c, and the value of the minimum critical angle depends on the ratio of the refractive indices of the two media, that is, the range of the core is less than 90. . Therefore, the critical angle of 0 can be known. It is equal to -1 (1/1.49) = 42.2. 'And the first incident angle; (3 ranges from 42.2 to 90°. The first incident angle is cooled to 42 2 and 0 is less than 9 〇. The strip ft is substituted into Sin, (112/1^). (203 (^ +)), know that the first acute angle is greater than 5.6° 〇θ, θ 6 83.28 7 76.8 8 72.6 Table 1. Θ, relationship with 0. Table 1 is based on the above equation θ = sin-i( (η2/ Ηι) · cos(万+ 201017288

4Z1TW 27357twf..doc/n

0')) A table of the relationship between the first acute angle 0' and the second incident angle (9). As can be seen from Table 1, when the value of the first acute angle 0' is larger, the value of the second incident angle 0 will be higher. Referring to FIG. 5A, the incident angle of the light emitted by the light source below the light incident side surface 430 is 7 Γ, and the incident angle of the light entering the light guide plate without being totally reflected is 0 '. Therefore, the light utilization ratio is 0 / π x 100% 'so the light utilization rate will be proportional to 0. As can be seen from the above, when the value of 0 is larger, the light utilization rate is lower. Therefore, when Θ '= 5.6, it is the second slope of the light path adjustment structure 450. The optimum angle of formation of the angle 456 with the first reference plane pi. Figure 5B is a schematic diagram of the number of layers of the second slope and the other physical parameters of the light guide plate of the light path adjustment structure. Please refer to Figure 5B to confirm the second After the angle between the slope 456 and the first reference plane P1, the number of layers of the second slope 456 of the light path adjustment structure 450 can be known by the following two relations: η > (ln(Xmin/x) yT% With n > (L /

z) · tan0', where Xmin is the minimum value of the backlight module brightness, D% is the transmittance of the light emitted by the light source through a single light path adjustment structure 45, = is the source brightness 'z is the first reference plane P1 to the visible area distance, L is the total side length of the opposite side of the light guide plate, and the Saki observation must be greater than the larger of the two η values obtained by the above two formulas, wherein the figure is only schematically shown The structure is adjusted for a five-layer light path. In addition, the Z-two reference planes of one of the light path adjusting structures 45G: the orthographic projections on the two are superposed on the light guide plate and the other light path is 5, and the peaks 454 of the entire structure 45〇 are formed on the thousands of faces P2. Orthographic projection coffee. In other words, the light path adjustment structures 450 on the reflective side 440 on both sides of the guide 400 15 201017288 rv> /uouioiviZlTW 27357twf..doc/n are mutually symmetrical. It can be seen from the above that after the light of the light source 500 enters the light guide plate 400 from the light incident side surface 430, the light of the light path adjusting structure 450 that is incident on the reflective side surface 44 changes its light path to reduce the light loss on both sides of the light guide plate 400. And the light utilization efficiency is improved. Therefore, it is possible to improve the problem that the light-emitting area of the conventional backlight module 1 has a dark area on both sides of the vertical direction of the tube 20 to form a waistband dark band (refer to FIG. 1B and FIG. 1c). Therefore, the brightness uniformity of the backlight module 300 can be improved by the light path adjusting structure 450, thereby improving the display quality of the liquid crystal display device 100. Further, a plurality of V-shaped grooves 800 may be provided on the light-emitting surface 410 of the light guide plate 4'. Please refer to Fig. 4A. Thus, the brightness of the light emitting surface of the backlight module 300 can be effectively improved. Of course, the V-shaped groove 800 can also be disposed on the bottom surface 420 of the light guide plate 400 (not shown). In summary, the present invention arranges a light path adjustment on the reflective side of the light guide plate to improve the brightness of the dark area of the conventional backlight module by using the light path adjustment structure. Therefore, the backlight module using the light guide plate of the present invention has a uniform luminance, thereby improving the display quality of the liquid crystal display device. In addition, the combination, the test and the simulation of the Lin, can get the best light path adjustment knot, the inclination angle of the second slope and the number of layers design, so that the light can be adjusted by the light path, the structure of the design changes its light path It is used to reduce the loss of light on both sides of the guide and improve the light utilization efficiency, thereby improving the luminous efficiency of the backlight module. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the general knowledge of any one of the technical fields of the present invention, and does not depart from the spirit and scope of the present invention without departing from the spirit and scope of the present invention. The scope of protection of the present invention is subject to the definition of the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a top plan view of a conventional backlight module. FIG. 1B and FIG. 1C are schematic diagrams of a light guide plate using different types of V-shaped grooves for the backlight module of FIG. 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. 4A is a schematic diagram of a light source and a light guide plate of the backlight module of FIG. 3. 4B is a top plan view of the light source and the light guide plate of the backlight module of FIG. 4A. Fig. 5A is a partially enlarged schematic view showing the optical path adjustment structure of the light incident side surface and the reflective side surface of the light guide plate of the present invention. Fig. 5B is a schematic view showing the number of layers of the second slope and the other physical parameters of the light guide plate of the light path adjusting structure. [Main component symbol description] 1 : Backlight module ίο, ίο' : Light board 10a. Light exit surface l〇b, l〇b': bottom surface 12: dot 14: optical diaphragm 17 201017288_w 27357twf..doc/n 16 : reflection Sheet 20: Lamp 100: Liquid crystal display device 200. Liquid crystal display panel 300: Backlight module 400: Light guide plate 410: Light exit surface 420: Bottom surface 430: Light incident side surface 440: Reflective side surface 450: Light path adjustment structure 450a: Trench 452: first slope 452a: first end 454: peak 454a: orthographic projection 10 456: second slope 456a: second end 500: light source 600: reflective sheet 700: frame 800: V-shaped groove A. dark Region P1: first reference plane 18 201017288viZ1TW 27357twf..doc/n P2 : normal to the second slope β 'first--incident angle Θ: first: two incident angle Θ, : first acute angle dl: first - distance X : Incident light quantity Z: distance from the first reference plane to the visible area L: side length of the light guide plate

19

Claims (1)

201017288^ 27357twf..doc/n X. Application for Patent Park: h A backlight module comprising: a light guide plate having a light exit surface, a bottom surface, at least a light incident side surface and two opposite reflective sides, the light output The surface is opposite to the bottom surface, and the reflective side surfaces and the light incident side surfaces are connected between the light emitting surface and the bottom surface, wherein each of the reflective side surfaces has a light path adjusting structure, and each of the path adjusting structures comprises: a plurality of trenches, each of the trenches having a first slope, a peak, and a second slope intersecting the first slope with the first slope, wherein the first slope of each of the trenches is away from the peak a first end is spaced apart from a second end of the corresponding second bevel away from the peak by a first distance; and at least one light source is disposed beside the light incident side. 2. The backlight module of claim 1, wherein the light guide plate further has a first reference plane, the first reference plane is substantially perpendicular to the light incident side surface, and the second slope of the second surface is A first acute angle is sandwiched between the first reference planes. 3. The backlight module of claim 2, wherein each of the first acute angles is 5.6 degrees. 4. The backlight module of claim 1, wherein the light guide plate has a normal line and the normal line is perpendicular to the second slope, and the normal line and a light incident path of the light guide plate are sandwiched. A first angle of incidence. 5. The backlight module of claim 4, wherein each of the first incident angles ranges from 42.2 degrees to 90 degrees. 20 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The G-ports of the other light path adjustment structures form the orthographic projections on the dich-reference plane. ^ 7. As claimed in the application of the 背 丨 之 之 之 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 其中 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背 背The m-module, wherein the length of the first bevel is greater than the length of the second bevel. The backlight module of claim 1, wherein the first crotch surface has a length greater than the first bevel The backlight module of claim 1, wherein the light source is a cold cathode fluorescent lamp. 11. The backlight module of claim 1, wherein the backlight module The light source is a light emitting diode. A liquid crystal display device comprising: a liquid crystal display panel; and a backlight module disposed under the liquid crystal display panel, comprising: a light guide plate having a light emitting surface, a bottom surface, at least one light incident side surface, and two opposite a light-reflecting side surface, the light-emitting surface is opposite to the bottom surface, and the light-reflecting side surfaces and the light-incident side surfaces are connected between the light-emitting surface and the bottom surface, wherein each of the light-reflecting sides has a light path adjusting structure The light path adjusting structure comprises: a plurality of grooves, each of the grooves having a first inclined surface, a peak 21 201017288..zitw 27357twf..doc/n portion, and a portion opposite to the first inclined surface of the peak portion a slope, wherein a first % of the first slope of each of the trenches away from the peak is at a first distance from a second end of the corresponding second slope away from the peak; and at least one light source 'Configured on the side of the light entrance. 13. The liquid crystal display device of claim 12, wherein the phosphor plate further has a first reference plane, the first reference plane being substantially perpendicular to the entrance plane, and the second slope and the first reference The first acute angle of the plane. 14. The first acute angle of the liquid crystal display device according to claim 13 is 5.6 degrees. In the liquid crystal display device of claim 12, the light guide plate has a normal line, and the normal line is perpendicular to the second inclined surface, and the 誃 线 line and one of the light guide plates The light incident path is sandwiched by a first angle of incidence. <16. The liquid crystal display device of claim 15, wherein the first incident angle ranges from 422 degrees to 9 degrees. 17. The liquid crystal display of the liquid crystal display according to claim 12, wherein the orthographic projections of the peaks formed by the peaks of the one of the light path adjusting structures are coincident with In addition, the = portion of the light path adjustment structure forms the orthographic projections on the second reference plane. The liquid crystal display device of claim 12, wherein the peaks are formed at a midpoint of the first distance of the first turn. The liquid crystal display device of claim 12, wherein the length of the first slope is greater than the length of the second slope in 22 .. Z1TW 27357 twf.. doc/n. 20. The liquid crystal display device of claim 12, wherein the length of the second slope is greater than the length of the first slope. 21. The liquid crystal display device of claim 12, wherein the light sources are cold cathode fluorescent lamps. 22. The liquid crystal display device of claim 12, wherein the light sources are light emitting diodes. twenty three