CN213843580U

CN213843580U - Light guide plate, backlight module and display device

Info

Publication number: CN213843580U
Application number: CN202022694190.5U
Authority: CN
Inventors: 张嘉尹; 翁巾婷; 钟翌菁; 陈昊
Original assignee: Radiant Opto Electronics Corp
Current assignee: Radiant Opto Electronics Corp
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-07-30
Anticipated expiration: 2030-11-19

Abstract

The utility model relates to a light guide plate, backlight unit and display device. The light guide plate is coupled with the light source and comprises a light emitting surface, a bottom surface, a light incident surface and a plurality of light guide microstructures. The bottom surface is opposite to the light-emitting surface, the light-in surface is connected between the light-emitting surface and the bottom surface, and light rays emitted by the light source enter the light guide plate through the light-in surface. The light guide microstructures are arranged on at least one of the light emitting surface and the bottom surface, and each light guide microstructure comprises a light facing surface and a light reflecting surface. The light-facing surface comprises a first reflecting surface and a second reflecting surface which are connected with each other, the inclination degree of the first reflecting surface is smaller than that of the second reflecting surface, and the light-reflecting surface is connected with one of the first reflecting surface and the second reflecting surface.

Description

Light guide plate, backlight module and display device

Technical Field

The utility model relates to a light guide plate, backlight unit and display device, and especially relate to the light guide plate of the optical path of regulation and control light through the plane of reflection that sets up two kinds of different slope degrees, contain backlight unit and display device of this light guide plate.

Background

With the development of technology, electronic devices such as mobile phones, tablet computers, notebook computers, and Display devices for vehicles, which are mounted with Liquid Crystal Display (LCD) panels, have become indispensable articles in modern life. Since the LCD panel itself does not emit light, a backlight unit is required to provide a surface light source. The backlight module comprises a light source and a light guide plate, wherein light rays emitted by the light source are guided by the light guide plate and then emitted from a light emitting surface of the light guide plate to form a surface light source. The light-emitting quality of the backlight module, such as luminance and light-emitting angle, is related to the image quality of the LCD panel and the subsequent application level. Therefore, the related industries are not dedicated to improving the structure of the backlight module to make the light quality of the backlight module meet the specifications of LCD panels in different application layers.

Referring to fig. 1, which is a schematic view of a conventional backlight module 1, the backlight module 1 includes a light source 2 and a light guide plate 3, and the light source 2 is disposed corresponding to a light incident surface 6 of the light guide plate 3. The bottom surface 4 of the light guide plate 3 is formed with a plurality of light guide microstructures 7, each of the light guide microstructures 7 includes a light facing surface 8 and a light reflecting surface 9, an included angle θ is formed between the light facing surface 8 and the length direction D of the light guide plate 3, and when the included angle θ is configured to be a small angle, for example, smaller than 10 degrees, it is favorable for the light L to be emitted from the light emitting surface 5 after being reflected for a plurality of times, so that the angle of the light L relative to the light emitting surface 5 is smaller than the total reflection angle. Therefore, the optical path of the light L in the light guide plate 3 can be extended, and the backlight module 1 can be configured as a directional backlight module, which can provide a more concentrated light-emitting angle and higher luminance, thereby being beneficial to an LCD panel with concentrated viewing angle requirements and high luminance requirements.

However, since the optical path of the light L is long, the light L is emitted after forming multiple total reflections in the light guide plate 3, and therefore a dark band appears in the area a close to the light incident surface 6 of the light guide plate 3, which results in a defect of uneven brightness. To solve the aforementioned drawbacks, the tunnel industry increases the density of the light guiding microstructures 7 in the area a, i.e. increases the number of light guiding microstructures 7 per unit length. Thus, although the occurrence of dark bands in the area a can be reduced, the appearance and taste of the backlight module 1 are also affected by the boundary line (i.e., the boundary line between dense and sparse) formed by the change in the arrangement density of the light guide microstructures 7, which is directly observed from the outside of the light guide plate 3.

Therefore, how to improve the structure of the backlight module to improve the brightness uniformity and make the light-emitting quality of the backlight module meet the specifications of LCD panels in different application levels is an object of the related manufacturers.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a light guide plate, backlight unit and display device to solve above-mentioned problem.

According to an embodiment of the present invention, a light guide plate is provided for coupling with a light source. The light guide plate comprises a light emitting surface, a bottom surface, a light incident surface and a plurality of light guide microstructures. The bottom surface is opposite to the light-emitting surface, the light-in surface is connected between the light-emitting surface and the bottom surface, and light rays emitted by the light source enter the light guide plate through the light-in surface. The light guide microstructures are arranged on at least one of the light emitting surface and the bottom surface and comprise a light facing surface and a light reflecting surface. The light-facing surface comprises a first reflecting surface and a second reflecting surface which are connected with each other, wherein the inclination degree of the first reflecting surface is smaller than that of the second reflecting surface, and the light-reflecting surface is connected with one of the first reflecting surface and the second reflecting surface.

Compared with the prior art, the utility model discloses a light guide plate accessible sets up the different first plane of reflection and the second plane of reflection of degree of inclination at the light-admitting face of leaded light microstructure, regulates and control the optical path of light, can provide the longer and shorter light of optical path from this simultaneously, is favorable to promoting the luminance homogeneity of light guide plate on the one hand, and on the other hand can regulate and control the light-emitting position of the longer and shorter light of optical path, light-emitting angle and distribution proportion to satisfy the required specification of the LCD panel of different application aspect.

Drawings

Fig. 1 is a schematic cross-sectional view of a conventional backlight module.

Fig. 2 is a schematic perspective view of a light guide plate according to an embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of the light guide plate of fig. 2.

Fig. 4 is a schematic cross-sectional view of a light guide plate according to another embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 8 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 9 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 10 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 11 is a schematic cross-sectional view of a light guide plate according to still another embodiment of the present invention.

Fig. 12 is a perspective view of a light guide plate according to still another embodiment of the present invention.

Fig. 13 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention.

Fig. 14 is a schematic cross-sectional view of a display device according to still another embodiment of the present invention.

Detailed Description

The foregoing and other technical contents, features and effects of the present invention will be more clearly understood from the following detailed description of the preferred embodiments with reference to the accompanying drawings. The following embodiments refer to directional terms such as: up, down, left, right, front, back, bottom, top, etc., with reference only to the orientation of the figures. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting. Further, in the following embodiments, the same or similar elements will be denoted by the same or similar reference numerals.

The utility model discloses in, the light guide plate can be used to backlight unit, and backlight unit can be used to provide the light source of Liquid Crystal Display (LCD) panel, and each component among the backlight unit contains bottom surface and top surface, and the definition of bottom surface and top surface uses the LCD panel as the reference standard, and the one side of keeping away from the LCD panel of each component is the bottom surface, and is the top surface towards the one side of LCD panel. In addition, in the present invention, the one element is disposed above the other element, which means that the one element is disposed above the top surface of the other element or the top surface of the other element.

In the present invention, "light-facing surface" refers to a surface facing the light source, and "light-reflecting surface" refers to a surface opposite to the light-facing surface and opposite to the light source.

In the present invention, the section lines in the cross-sectional schematic diagram are omitted for the sake of brevity.

Referring to fig. 2 and 3, fig. 2 is a schematic perspective view of a light guide plate 100 according to an embodiment of the present invention, and fig. 3 is a schematic cross-sectional view of the light guide plate 100 of fig. 2. The light guide plate 100 is used to couple with a light source (see the light source 11 in fig. 13), and the light beam emitted from the light source generally includes a plurality of parallel light beams (e.g. the first light beam L shown in fig. 3)₁And the second light L₂) The light guide plate 100 includes a light emitting surface 110, a bottom surface 120, a light incident surface 130, and a plurality of light guide microstructures 140. The bottom surface 120 is opposite to the light emitting surface 110, the light incident surface 130 is connected between the light emitting surface 110 and the bottom surface 120, and the light emitted from the light source, such as the first light L₁And the second light L₂The light enters the light guide plate 100 through the light incident surface 130, and is guided by the light guide plate 100 to be emitted from the light emitting surface 110. Light guide microstructures 140 are disposed on bottom surface 120. However, the present invention is not limited thereto, and in other embodiments, the light guiding microstructure 140 may be disposed on the light emitting surface 110, or the light guiding microstructure 140 may be disposed on the light emitting surface 110 and the bottom surface 120 at the same time.

Each light guide microstructure 140 includes a light facing surface 141 and a light reflecting surface 142, the light facing surface 141 includes a first reflecting surface 143 and a second reflecting surface 144 connected to each other, the first reflecting surface 143 is closer to the light incident surface 130 than the second reflecting surface 144, an inclination degree of the first reflecting surface 143 is smaller than an inclination degree of the second reflecting surface 144, and the first reflecting surface 143 is connected to the light reflecting surface 142.

As shown in FIG. 3, the inclination of the first reflecting surface 143A first light L emitted from the light source with a small inclination₁The first light L can be reflected for several times₁The angle of the second reflecting surface 144 is smaller than the total reflection angle with respect to the light emitting surface 110 and is emitted from the light emitting surface 110, the inclination degree of the second reflecting surface 144 is large, and the second light L emitted from the light source is emitted₂The second light L can be reflected for a few times₂The angle with respect to the light emitting surface 110 is smaller than the total reflection angle and is emitted from the light emitting surface 110. Therefore, although the first light L₁And the second light L₂The second light L enters the light guide plate 100 from the light incident surface 130 in a parallel manner, but after the first reflection surface 143 and the second reflection surface 144 with different inclinations reflect, the second light L₂The incident angle theta 3 to the normal direction N of the light emitting surface 110 is smaller than the first light L₁An incident angle θ 5 to the normal direction N of the light emitting surface 110, so that the light beam emitted from the light source can provide a light ray with a long optical path (e.g. the first light ray L) after entering the light guide plate 100₁The incident angle is large, so that the total reflection is easily formed in the light guide plate 100 to form the effect of long optical path) and the light ray with short optical path (for example, the second light ray L)₂The incident angle is small, so that the light is easily refracted from the light guide plate 100 to the external environment, thereby forming an effect of a short optical path). In other words, the inclination degree of the first reflecting surface 143 is less than that of the second reflecting surface 144, so that the light (such as the first light L) entering the light guide plate 100₁The second light L₂) The path reflected by the second reflecting surface 144 is more inclined to the normal direction N of the light emitting surface 110 than the path reflected by the first reflecting surface 143. Thus, the second light L can be emitted₂Compared with the first light L₁Light is emitted more in advance.

With the above structure, the light guide plate 100 of the present invention can regulate the optical path of light, thereby providing light with a longer optical path (e.g. the first light L)₁) And light with shorter optical path (such as the second light L)₂) Therefore, the light with a short optical path is easily refracted to the external environment by the light guide plate 100, so as to improve the dark band in the area a1 of the light guide plate 100 near the light incident surface 130, thereby improving the light guideThe brightness uniformity of the panel 100. On the other hand, the light-emitting position, the light-emitting angle and the distribution ratio of the light with the longer optical path and the shorter optical path can be further adjusted and controlled by adjusting the inclination degree and/or the length of the first reflecting surface 143 and the second reflecting surface 144, so as to meet the specifications required by the LCD panels of different subsequent application layers.

In detail, as shown in fig. 3, the light guide plate 100 defines a first length direction D1, the first length direction D1 is perpendicular to the light incident surface 130, a first included angle θ 1 is formed between the first reflection surface 143 and the first length direction D1, and the larger the first included angle θ 1 is, the larger the inclination degree of the first reflection surface 143 is. The second reflecting surface 144 has a second included angle θ 2 with the first longitudinal direction D1, and a larger second included angle θ 2 indicates a larger inclination degree of the second reflecting surface 144. Since the inclination degree of the first reflecting surface 143 is smaller than that of the second reflecting surface 144, it satisfies the following condition: θ 1< θ 2.

In fig. 2 and 3, for clarity, the light guiding microstructures 140 are additionally labeled along the first length direction D1, i.e., they are labeled as light guiding

microstructures

140a, 140b, and 140c in sequence. In the light guiding microstructure 140a, a projection length of the first reflecting surface 143 in the first length direction D1 is a₁The projection length of the second reflecting surface 144 in the first length direction D1 is b₁The light guide microstructure 140a has a ratio P₁Ratio P₁Is the projection length b of the second reflecting surface 144 in the first length direction D1₁Divided by the projection length a of the first reflecting surface 143 in the first longitudinal direction D1₁Which satisfies the following conditions: p₁＝b₁/a₁. Similarly, light guiding microstructure 140b has a ratio P₂Ratio P₂Is the projection length b of the second reflecting surface 144 in the first length direction D1₂Divided by the projection length a of the first reflecting surface 143 in the first longitudinal direction D1₂Which satisfies the following conditions: p₂＝b₂/a₂. Light guiding microstructure 140c has a ratio P₃Ratio P₃Is the projection length b of the second reflecting surface 144 in the first length direction D1₃Divided by the projection length a of the first reflecting surface 143 in the first longitudinal direction D1₃It is full ofThe following conditions are satisfied: p₃＝b₃/a₃In the present embodiment, the ratio P of all the light guide microstructures 140₁、P₂、P₃Are all the same, i.e. P₁＝P₂＝P₃. Therefore, the distribution ratio of the light with the longer optical path and the shorter optical path along the first length direction D1 is fixed, so that the mold of the light guide plate 100 is easy to manufacture, which is beneficial to reducing the production cost. However, the present invention is not limited thereto, and in other embodiments, the ratio P of the plurality of light guiding microstructures 140 can be adjusted along the first length direction D1₁、P₂、P₃For example, the ratio of the light guiding microstructures 140 far from the light incident surface 130 can be made smaller than the ratio of the light guiding microstructures 140 near the light incident surface 130, as shown in fig. 4, fig. 4 is a schematic cross-sectional view of a light guiding plate 100 'according to another embodiment of the present invention, the light guiding plate 100' is different from the light guiding plate 100 of fig. 3 in that the projection lengths of the first reflecting surfaces 143 of the light guiding microstructures 140a, 140b, and 140c in the first length direction D1 are gradually increased, that is, a₁<a₂<a₃The projection length of the second reflective surface 144 of the light guiding microstructures 140a, 140b, 140c in the first length direction D1 is gradually decreased, i.e. b₁>b₂>b₃Thus P is₁>P₂>P₃. In other embodiments, P₁、P₂、P₃The following conditions may be satisfied: p₁>P₂＝P₃Or P₁＝P₂>P₃. In other words, the ratio of the plurality of light guiding microstructures 140 may be configured to decrease along the first length direction D1, including decreasing along the first length direction D1 (i.e. the ratio of each light guiding microstructure 140 is different), and also including dividing the plurality of light guiding microstructures 140 into a plurality of groups along the first length direction D1, where the ratio of the light guiding microstructures 140 in a same group is the same, and the ratio of the light guiding microstructures 140 in different groups is different. As shown in fig. 4, the ratio P of the light guiding microstructures 140a adjacent to the light incident surface 130 is₁Larger, i.e., the projection length a of the first reflecting surface 143 of the light guiding microstructure 140a₁Shorter, smaller area, thereby reducing the proportion of total reflection,reducing the light of long optical path, the projection length b of the second reflecting surface 144 of the light guiding microstructure 140a₁The longer and larger area can increase the proportion of light transmitted out of the light guide plate 100' and increase the short-path light, thereby providing a higher proportion of light with a shorter optical path at the region a1 near the light incident surface 130, and further improving the occurrence of dark bands at the region a1 near the light incident surface 130. On the other hand, for the position of the light guide plate 100' far from the light incident surface 130, it is not necessary to use the short-path light to improve the dark band, so the design can be mainly based on the long-path light output, so that the projection length b of the second reflection surface 144 of the light guide microstructure 140c is made to be longer₃Shorter, smaller area, projected length a of the first reflective surface 143 of the light guiding microstructure 140c₃Longer and larger area, i.e. the ratio P of the light guiding micro-structures 140c far away from the light incident surface 130₃Smaller to meet the light extraction requirement.

In fig. 3 and 4, each light guiding microstructure 140 is a protruding light guiding microstructure, i.e., formed by protruding outward from the surface on which it is disposed (here, bottom surface 120). However, the present invention is not limited thereto, and in other embodiments, each light guiding microstructure 140 may also be a recessed light guiding microstructure, i.e. formed by the surface on which it is disposed being recessed inward.

In fig. 3 and 4, a plurality of light guiding microstructures 140 are arranged at intervals along first length direction D1 and at equal intervals. However, the present invention is not limited thereto, and in other embodiments, the plurality of light guiding microstructures 140 may be disposed at intervals along the first length direction D1, and the size of the space between two adjacent light guiding microstructures 140 may be changed, or the plurality of light guiding microstructures 140 may be disposed continuously along the first length direction D1. By adjusting the density of the light guide microstructures 140 along the first length direction D1, different light output qualities can be provided to meet the specifications required by LCD panels of different application layers.

Please refer to fig. 5 to 7, which are schematic cross-sectional views of

light guide plates

200, 300, and 400 according to another embodiment of the present invention. The

light guide microstructures

240, 340, 440 are disposed on the bottom surface 120. Each

light guiding microstructure

240, 340, 440 includes a light facing surface 241, 341, 441 and a light reflecting surface 242, 342, 442, and the light facing surface 241, 341, 441 includes a first reflecting

surface

243, 343, 443 and a second reflecting

surface

244, 344, 444 connected to each other. The difference lies in that: each light guiding microstructure 240 in fig. 5 is a protruding light guiding microstructure, the first reflecting surface 243 is farther from the light incident surface 130 than the second reflecting surface 244, and the second reflecting surface 244 is connected to the light reflecting and facing surface 242; each light guiding microstructure 340 of fig. 6 is a concave light guiding microstructure, the first reflecting surface 343 is closer to the light incident surface 130 than the second reflecting surface 344, and the second reflecting surface 344 is connected to the light reflecting and facing surface 342; each of the light guiding microstructures 440 of fig. 7 is a concave light guiding microstructure, the first reflecting surface 443 is farther from the light incident surface 130 than the second reflecting surface 444, and the first reflecting surface 443 is connected to the light reflecting surface 442.

Please refer to fig. 8, which is a schematic cross-sectional view of a light guide plate 500 according to another embodiment of the present invention. The light guide microstructure 540 is disposed on the light emitting surface 110. Each light guide microstructure 540 is a protruding light guide microstructure and includes a light facing surface 541 and a light reflecting surface 542, the light facing surface 541 includes a first reflecting surface 543 and a second reflecting surface 544 connected to each other, the first reflecting surface 543 is closer to the light incident surface 130 than the second reflecting surface 544, and the first reflecting surface 543 is connected to the light reflecting surface 542.

The first reflecting surface 543 and the second reflecting surface 544 of the present embodiment are similar to the light source, so that the light beam emitted from the light source can simultaneously provide the light L with a long optical path after entering the light guide plate 500₁(the light L impinging on the first reflecting surface 543 easily forms total reflection in the light guide plate 500 to have a long optical path) and the light L having a short optical path₂(the light impinging on the second reflecting surface 544 is easily refracted by the light guide plate 100 to the external environment, resulting in a short optical path). In addition, since the bottom of the light guide plate 500 is further provided with the reflective sheet 550, the light is reflected by the light guide microstructures 540 arranged on the light emitting surface 110 and passes through the bottom surface 120 of the light guide plate 500, and then can be reflected again by the reflective sheet 550 and return to the light guide plate 500, and the light L with a short optical path is generated₂Light L having a longer optical path than the incident angle₁Is smaller than the long-path light L₁Refract out the guided light more in advanceA plate 500.

Please refer to fig. 9 to 11, which are schematic cross-sectional views of

light guide plates

600, 700, 800 according to still another embodiment of the present invention. The

light guide microstructures

640, 740, and 840 are disposed on the light emitting surface 110. Each

light guiding microstructure

640, 740, 840 includes a

light facing surface

641, 741, 841 and a

light reflecting surface

642, 742, 842, and the

light facing surface

641, 741, 841 includes a

first reflection surface

643, 743, 843 and a

second reflection surface

644, 744, 844 connected to each other. The difference lies in that: each light guiding microstructure 640 in fig. 9 is a protruding light guiding microstructure, the first reflection surface 643 is farther from the light incident surface 130 than the second reflection surface 644, and the second reflection surface 644 is connected to the light reflection surface 642; each light guiding microstructure 740 in fig. 10 is a concave light guiding microstructure, the first reflective surface 743 is closer to the light incident surface 130 than the second reflective surface 744, and the second reflective surface 744 is connected to the light reflecting and facing surface 742; each of the light guide microstructures 840 of fig. 11 is a concave light guide microstructure, the first reflecting surface 843 is farther from the light incident surface 130 than the second reflecting surface 844, and the first reflecting surface 843 is connected to the light reflecting and facing surface 842.

Please refer to fig. 12, which is a schematic perspective view of a light guide plate 900 according to another embodiment of the present invention. Compared to the light guide plate 100, the light guide plate 900 further includes a plurality of strip-shaped microstructures 950, the plurality of strip-shaped microstructures 950 are formed on the bottom surface 120, each strip-shaped microstructure 950 has an extending direction E1, the extending direction E1 is perpendicular to the light incident surface 130 and is substantially parallel to the first length direction D1. Light guide microstructures 940 are disposed on bottom surface 120 and between adjacent stripe microstructures 950. However, the present invention is not limited thereto, and in other embodiments, the plurality of bar-shaped microstructures 950 may be formed on the light-emitting surface 110, and the light guide microstructures 940 may be disposed on the light-emitting surface 110 and between the adjacent bar-shaped microstructures 950. By providing the strip-shaped microstructures 950 on the light guide plate 900, light can be guided to the side away from the light incident surface 130. In this embodiment, each light guide microstructure 940 is a protrusion light guide microstructure and includes a light facing surface 941 and a light reflecting surface 942, the light facing surface 941 includes a first reflecting surface 943 and a second reflecting surface 944 connected to each other, the first reflecting surface 943 is closer to the light incident surface 130 than the second reflecting surface 944, and the first reflecting surface 943 is connected to the light reflecting surface 942.

For further details of the

light guide plates

100', 200, 300, 400, 500, 600, 700, 800, and 900, reference may be made to the light guide plate 100, which is not repeated herein.

Please refer to fig. 13, which is a schematic cross-sectional view of a backlight module 10 according to another embodiment of the present invention. The backlight module 10 includes a light guide plate 100 and a light source 11, wherein the light source 11 is disposed corresponding to the light incident surface 130 of the light guide plate 100. Here, the Light source 11 is exemplified by a Light Emitting Diode (LED) Light bar. However, the present invention is not limited thereto, and in other embodiments, the light source 11 may be, but not limited to, a Cold Cathode Fluorescent Lamp (CCFL). By providing the light guide plate 100, the backlight module 10 can provide better brightness uniformity, and adjust the light-emitting position, light-emitting angle and distribution ratio of the light with longer and shorter optical paths, so as to meet the specifications required by LCD panels of different application layers. In addition, the light guide plate 100 may be replaced with other light guide plates according to the present invention, such as the aforementioned

light guide plates

100', 200, 300, 400, 500, 600, 700, 800, or 900.

The backlight module 10 optionally further includes a prism sheet 12 disposed above the light guide plate 100, the prism sheet 12 is formed with a plurality of prism structures 12a, each prism structure 12a has a prism extension direction E2, the prism extension direction E2 is parallel to the light incident surface 130, is substantially perpendicular to the first length direction D1, and is a direction perpendicular to the paper surface in fig. 13. In this embodiment, the prism structure 12a is a rectangular prism-shaped microstructure (V-cut), but the present invention is not limited thereto, and the prism structure 12a may also be a cylindrical rectangular microstructure (R-cut). In fig. 13, the prism structure 12a faces the light guide plate 100, in other words, the prism sheet 12 is a reverse prism sheet, thereby facilitating the concentration of the light-emitting angle of the backlight module 10, and the backlight module 10 is configured as a directional backlight module to provide a more concentrated light-emitting angle and higher luminance. In addition, due to the ratio P of the light guiding microstructures 140₁、P₂、P₃(refer to the related explanation of fig. 3) is configured to be greater than 0 and less than or equal to 1, and the first included angle θ 1, the second included angle θ 2 (refer to fig. 3) are configured to satisfy the following condition: 0.5 degree<θ1<3.5°；3.5°<θ2<15 °, the light-emitting angle of the backlight module 10 can be further concentrated, and the directivity of the backlight module 10 can be enhanced. However, the present invention is not limited thereto, and in other embodiments, the prism sheet 12 may be a general prism sheet, and the prism structure 12a thereof may be far from the light guide plate 100.

The backlight module 10 may optionally be added with other optical films, such as a reflective film, a diffusion film, or another prism film, to provide the desired optical properties.

Please refer to fig. 14, which is a schematic cross-sectional view of a display device 30 according to another embodiment of the present invention. The display device 30 includes a backlight module 10 and a display panel 20, wherein the display panel 20 is disposed above the backlight module 10. The backlight module 10 is used for providing light to the display panel 20, and the display panel 20 may be an LCD panel, and for details of the backlight module 10, reference is made to the above description, which is not repeated herein.

Compared with the prior art, the utility model discloses a light guide plate accessible sets up the different first plane of reflection and the second plane of reflection of degree of inclination at the light-directing surface of meeting of leaded light microstructure, regulates and control the optical path of light, can provide the longer and shorter light of optical path from this simultaneously, is favorable to promoting the luminance homogeneity of light guide plate on the one hand, and on the other hand can regulate and control the light-emitting position and the distribution proportion of the longer and shorter light of optical path to satisfy the required specification of the LCD panel of different application aspect.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the claims of the present invention should be covered by the present invention.

[ List of reference numerals ]

1. 10: backlight module

2. 11: light source

3. 100, 100', 200, 300, 400, 500, 600, 700, 800, 900: light guide plate

4. 120: bottom surface

5. 110: light emitting surface

6. 130, 130: light incident surface

7. 140, 140a, 140b, 140c, 240, 340, 440, 540, 640, 740, 840, 940: light guide microstructure

8. 141, 241, 341, 441, 541, 641, 741, 841, 941: light-facing surface

9. 142, 242, 342, 442, 542, 642, 742, 842, 942: light reflecting surface

12: prism sheet

12 a: prism structure

20: display panel

30: display device

143. 243, 343, 443, 543, 643, 743, 843, 943: first reflecting surface

144. 244, 344, 444, 544, 644, 744, 844, 944: second reflecting surface

550: reflector plate

950: strip-shaped microstructure

A. A1: region(s)

a₁、a₂、a₃: the projection length of the first reflecting surface in the first length direction

b₁、b₂、b₃: the projection length of the second reflecting surface in the first length direction

D: length direction of the film

D1: first length direction

E1: direction of extension

E2: direction of prism extension

L: light ray

L₁: the first light ray

L₂: the second light ray

N: normal direction

θ: included angle

θ 1: first included angle

θ 2: second included angle

θ 3, θ 5: the angle of incidence.

Claims

1. A light guide plate for coupling with a light source, the light guide plate comprising:

a light-emitting surface;

a bottom surface opposite to the light emitting surface;

the light incident surface is connected between the light emergent surface and the bottom surface, and light rays emitted by the light source enter the light guide plate through the light incident surface; and

a plurality of light guiding microstructures disposed on at least one of the light emitting surface and the bottom surface, the light guiding microstructures comprising:

a light receiving surface including a first reflecting surface and a second reflecting surface connected to each other, wherein an inclination degree of the first reflecting surface is smaller than an inclination degree of the second reflecting surface; and

and a light reflection surface connected to one of the first reflection surface and the second reflection surface.

2. The light guide plate according to claim 1, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, a first included angle θ 1 is formed between the first reflective surface and the first length direction, and a second included angle θ 2 is formed between the second reflective surface and the first length direction, and the following conditions are satisfied: θ 1< θ 2.

3. The light guide plate according to claim 1, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, the light guide microstructures have a ratio, the ratio is a projection length of the second reflective surface in the first length direction divided by a projection length of the first reflective surface in the first length direction, and the ratio of all the light guide microstructures is the same.

4. The light guide plate according to claim 1, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, the light guiding microstructures have a ratio of a projected length of the second reflective surface in the first length direction divided by a projected length of the first reflective surface in the first length direction, and the ratio of the light guiding microstructures away from the light incident surface is smaller than the ratio of the light guiding microstructures adjacent to the light incident surface.

5. The light guide plate according to claim 1, wherein the first reflective surface is closer to the light incident surface than the second reflective surface, and the first reflective surface is connected to the light reflection surface.

6. The light guide plate according to claim 1, wherein the first reflective surface is farther from the light incident surface than the second reflective surface, and the second reflective surface is connected to the light reflection surface.

7. The light guide plate of claim 1, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, and the plurality of light guide microstructures are continuously disposed along the first length direction.

8. The light guide plate of claim 1, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, and the plurality of light guide microstructures are disposed at intervals along the first length direction.

9. The light guide plate of claim 1, wherein the light guiding microstructures are protruding light guiding microstructures or recessed light guiding microstructures.

10. The light guide plate according to claim 1, further comprising:

a plurality of strip-shaped microstructures formed on the light emergent surface or the bottom surface, wherein the strip-shaped microstructures have an extending direction which is vertical to the light incident surface,

the light guide microstructures are arranged between the adjacent strip-shaped microstructures.

11. A backlight module, comprising:

a light guide plate according to any one of claims 1 to 10; and

the light source is arranged corresponding to the light incident surface of the light guide plate.

12. The backlight module as claimed in claim 11, further comprising:

the prism sheet is arranged above the light guide plate, wherein a plurality of prism structures are formed on the prism sheet.

13. The backlight module as claimed in claim 12, wherein the prism structure faces the light guide plate, and the prism structure has a prism extending direction parallel to the light incident surface.

14. The backlight module according to claim 12, wherein the light guide plate defines a first length direction, the first length direction is perpendicular to the light incident surface, the light guide microstructure has a ratio, the ratio is a projection length of the second reflective surface in the first length direction divided by a projection length of the first reflective surface in the first length direction, and when the inclination degree of the first reflective surface is smaller than the inclination degree of the second reflective surface, the ratio is greater than 0 and less than or equal to 1.

15. A display device, comprising:

a backlight module according to claim 11; and

and the display panel is arranged above the backlight module.