Light guide plate, manufacturing method thereof, and backlight module

Abstract

The present application relates to the field of display technologies, and particularly relates to a light guide plate, a manufacturing method thereof, and a backlight module. The light guide plate includes: a light-emitting surface and a bottom surface that face each other, a light-incident surface connected to the light-emitting surface and the bottom surface, and a plurality of light guide microstructures formed on the bottom surface; the shape of each light guide microstructure is formed to be symmetric about its respective imaginary plane, the imaginary plane being perpendicular to the bottom surface and the light-incident surface, and each light guide microstructure has a first surface, a second surface, and a third surface that are adjacent to each other, the first surface and the second surface being formed as two non-coplanar planes symmetrically arranged on both sides of the imaginary plane, and the third surface being formed to be symmetric about the imaginary plane and protruding in a direction away from the first surface and the second surface; wherein, the first surface and the second surface have a common edge located in the imaginary plane, and the common edge extends obliquely with respect to the bottom surface in such a manner that it gets closer to the third surface as it gets farther away from the bottom surface.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a light guide plate, a manufacturing method thereof, and a backlight module. Background Art

[0002] With the accelerated promotion of the global "dual carbon" goal, higher requirements have been put forward for LCD display panels, which represent the mainstream direction of display panels, in terms of energy-saving display, thinning, and ultra-narrow bezels. How to further improve the light efficiency of the backlight module of the LCD display screen, reduce the thickness of the light guide plate and the backlight module, and even achieve an ultra-narrow bezel (<5 mm) to achieve better display energy-saving, thinning, and the pursuit of beauty and fashion has become a research hotspot for display manufacturers in recent years.

[0003] The brightness of the light emitted from the backlight module is the most important factor affecting the brightness of the LCD display screen, and the brightness of the light emitted from the backlight module is mainly related to the light guide plate and the film structure disposed thereon. From the perspective of the light guide plate, currently, by adopting an asymmetric high-brightness light guide microstructure, the light coupled into the light guide plate is emitted from the light guide plate with a relatively narrow viewing angle distribution. Compared with the conventional laser circular light guide microstructure, the high-brightness light guide microstructure has a higher energy concentration, so the module has a higher central brightness value, and the current gain effect is 4-10%. For the film structure of the backlight module, usually two layers of brightness enhancement films are used to collect the energy of a large viewing angle and deflect the angle to the front viewing angle. At the same time, the uniformity of the light emitted from the backlight module is improved by adding upper and lower diffusion sheets.

[0004] With the requirement of product thinning, the traditional four-piece backlight module structure has encountered challenges, and two-piece ultra-thin structures such as 2P1D (where P is the abbreviation of Prism, that is, a prism sheet, and D is the abbreviation of Diffuser, that is, a diffusion sheet), 1P2D, and even 1P1D have emerged. At the same time, under the fashionable requirement of the display for an ultra-narrow bezel, the light guide plate is required to have an ultra-small A / P ratio, such as A / P < 0.7 (where A is the distance from the microstructure area to the light incident surface, and P is the abbreviation of Pitch, which is the arrangement period of LED lights).

[0005] Therefore, under the ultra-thin structure of the backlight module and the requirement of the ultra-narrow bezel of the display, how to meet the optical quality of the light incident port of the light guide plate, reduce the inter-lamp shadow and the bright spot in front of the lamp under a low A / P, how to ensure that the backlight module emits light from the front viewing field, and ensure sufficient brightness gain and meet the viewing angle requirements of the TCO, etc., pose extremely high technical requirements for the light guide plate and the backlight module. Summary of the Invention

[0006] In view of this, the present application proposes a light guide plate, a manufacturing method thereof, and a backlight module.

[0007] In a first aspect, the present application provides a light guide plate, comprising:

[0008] An outgoing light surface and a bottom surface that face each other,

[0009] An incoming light surface connected to the outgoing light surface and the bottom surface, and

[0010] A plurality of light guiding microstructures formed on the bottom surface;

[0011] The shape of each of the light guiding microstructures is formed to be symmetric about a respective imaginary plane perpendicular to the bottom surface and the incoming light surface. Each of the light guiding microstructures has a first surface, a second surface, and a third surface that are adjacent to each other. The first surface and the second surface are formed as two non-coplanar planes symmetrically arranged on both sides of the imaginary plane, and the third surface is formed as a curved surface that is symmetric about the imaginary plane and protrudes in a direction away from the first surface and the second surface;

[0012] Wherein, the first surface and the second surface have a common edge located in the imaginary plane, and the common edge extends obliquely with respect to the bottom surface in such a way that it is closer to the third surface as it is farther from the bottom surface.

[0013] In some possible implementation manners, each of the light guiding microstructures is formed as a recess recessed from the bottom surface, and the plurality of light guiding microstructures include a plurality of first light guiding microstructures and a plurality of second light guiding microstructures;

[0014] For each of the first light guiding microstructures, the first surface and the second surface are closer to the incoming light surface than the third surface;

[0015] For each of the second light guiding microstructures, the first surface and the second surface are farther from the incoming light surface than the third surface.

[0016] In some possible implementation manners, the bottom surface includes:

[0017] A first region adjacent to the incoming light surface;

[0018] A second region adjacent to the first region on a side of the first region opposite to the incoming light surface;

[0019] All of the plurality of first light guiding microstructures are arranged in the first region, and a part of the plurality of second light guiding microstructures is arranged in the first region and another part is arranged in the second region.

[0020] In some possible embodiments, the outer contour of the projection of the light guiding microstructure on the bottom surface has an internal angle θ1 defined by the first surface and the second surface, where 60° ≤ θ1 ≤ 210°.

[0021] In some possible embodiments, the outer contour of the projection has an arc segment defined by the third surface, and the arc segment is connected to the internal angle so that the two constitute the entire outer contour.

[0022] In some possible embodiments, the third surface is formed as one of the following: a part of a cylindrical surface, a part of a conical surface, a part of a spherical surface, a part of an ellipsoidal surface, a part of a parabolic surface.

[0023] In some possible embodiments, the cross-section of each light guiding microstructure in the imaginary plane is a triangle, and the triangle has a first base angle ε1 corresponding to the common side and a second base angle ε2 corresponding to the third surface, where 16° ≤ ε1 ≤ 40° and 19° ≤ ε2 ≤ 37°.

[0024] In some possible embodiments, ε1 ≥ 24°.

[0025] In some possible embodiments, the first surface, the second surface, and the third surface constitute all the inner surfaces of the recess. The first region is a region within 80 mm from the light incident surface, and the second region is a region outside 80 mm from the light incident surface. θ1 is 90°, 100°, 110°, or 120°, ε1 is 36°, and ε2 is 30°.

[0026] In a second aspect, the present application provides a light guide plate, including:

[0027] A light emitting surface and a bottom surface that face each other,

[0028] A light incident surface connected to the light emitting surface and the bottom surface, and

[0029] A plurality of light guiding microstructures formed on the bottom surface;

[0030] The shape of each light guiding microstructure is formed to be symmetric about its respective imaginary plane, and the imaginary plane is perpendicular to the bottom surface. Each light guiding microstructure has a fourth surface and a fifth surface adjacent to each other. The fifth surface is formed as a curved surface that is symmetric about the imaginary plane and protrudes in a direction away from the fourth surface. The fourth surface is formed as a plane that extends obliquely with respect to the bottom surface in such a way that it gets closer to the fifth surface as it gets farther from the bottom surface.

[0031] Among them, the multiple light guiding microstructures include multiple third light guiding microstructures, multiple fourth light guiding microstructures, and multiple fifth light guiding microstructures;

[0032] For the third light guiding microstructure, the corresponding imaginary plane has an acute angle x1 with the light incident surface; for the fourth light guiding microstructure, the corresponding imaginary plane has an acute angle x2 with the light incident surface, where the magnitude of x2 is equal to that of x1 but the direction is opposite; for the fifth light guiding microstructure, the corresponding imaginary plane is perpendicular to the light incident surface.

[0033] In some possible implementation manners, each of the light guiding microstructures is formed as a recess recessed from the bottom surface;

[0034] For each of the third light guiding microstructures and each of the fourth light guiding microstructures, the corresponding imaginary plane sequentially passes through the fourth surface and the fifth surface in a direction away from the light incident surface;

[0035] For each of the fifth light guiding microstructures, the corresponding imaginary plane sequentially passes through the fifth surface and the fourth surface in a direction away from the light incident surface.

[0036] In some possible implementation manners, x1≥30°.

[0037] In some possible implementation manners, the bottom surface includes:

[0038] A third region adjacent to the light incident surface;

[0039] A fourth region adjacent to the third region on a side of the third region opposite to the light incident surface;

[0040] Among them, the multiple third light guiding microstructures and the multiple fourth light guiding microstructures are both arranged in the third region, and a part of the multiple fifth light guiding microstructures is arranged in the third region and another part is arranged in the fourth region.

[0041] In some possible implementation manners, the fifth surface is formed as one of the following: a part of a cylindrical surface, a part of a conical surface, a part of a spherical surface, a part of an ellipsoidal surface, a part of a parabolic surface.

[0042] In some possible implementation manners, the cross-section of each of the light guiding microstructures in the imaginary plane is a triangle, the triangle has a third base angle ε3 corresponding to the fourth surface and a fourth base angle ε4 corresponding to the fifth surface, 16°≤ε3≤40°, 19°≤ε4≤37°.

[0043] In some possible implementation manners, ε3≥24°.

[0044] In a third aspect, the present application provides a backlight module, including:

[0045] a light source, and

[0046] a light guide plate as described in the first aspect or the second aspect;

[0047] wherein, the light source is disposed on the light incident surface side of the light guide plate and is configured to emit light towards the light incident surface.

[0048] In a fourth aspect, the present application provides a method for manufacturing the light guide plate as described in the first aspect, including:

[0049] providing a punch, the punch having a shape complementary to the light guide microstructure;

[0050] impacting the master plate at a plurality of positions with the punch at a first angle, thereby forming a plurality of first pits corresponding to the plurality of first light guide microstructures on the master plate;

[0051] impacting the master plate at a plurality of other positions with the punch at a second angle, thereby forming a plurality of second pits corresponding to the plurality of second light guide microstructures on the master plate, wherein both the first angle and the second angle are angles of the punch around the impact direction, and the first angle is different from the second angle;

[0052] transferring the first pits and the second pits of the master plate to a mold core through a mold transfer process, thereby forming a plurality of first protrusions on the mold core that are complementary in shape and corresponding in position to the plurality of first light guide microstructures, and a plurality of second protrusions that are complementary in shape and corresponding in position to the plurality of second light guide microstructures;

[0053] using the mold core having the first protrusions and the second protrusions to stamp and manufacture the light guide plate.

[0054] In a fifth aspect, the present application provides a method for manufacturing the light guide plate as described in the second aspect, including:

[0055] providing a punch, the punch having a shape complementary to the light guide microstructure;

[0056] impacting the master plate at a plurality of positions with the punch at a third angle, thereby forming a plurality of third pits corresponding to the plurality of third light guide microstructures on the master plate;

[0057] impacting the master plate at a plurality of other positions with the punch at a fourth angle, thereby forming a plurality of fourth pits corresponding to the plurality of fourth light guide microstructures on the master plate;

[0058] The striker strikes multiple other positions of the master template at a fifth angle, so as to form multiple fifth pits corresponding to the multiple fifth light guide microstructures on the master template, wherein the third angle, the fourth angle, and the fifth angle are all angles of the striker around the impact direction, and the third angle, the fourth angle, and the fifth angle are different from each other;

[0059] Transfer the third pits, the fourth pits, and the fifth pits of the master template to the mold core through a replication process, so as to form multiple third protrusions that are complementary in shape and corresponding in position to the multiple third light guide microstructures, multiple fourth protrusions that are complementary in shape and corresponding in position to the multiple fourth light guide microstructures, and multiple fifth protrusions that are complementary in shape and corresponding in position to the multiple fifth light guide microstructures on the mold core;

[0060] Use the mold core with the third protrusions, the fourth protrusions, and the fifth protrusions to imprint and manufacture the light guide plate.

[0061] According to the light guide plate provided in the first aspect of the present application, based on the fact that the first surface and the second surface of the first light guide microstructure are formed such that their common edge extends obliquely with respect to the bottom surface in a manner that the farther away from the bottom surface, the closer to the third surface, and the first surface and the second surface are not coplanar. Therefore, when the light emitted by the light source strikes the first surface and the second surface of the first light guide microstructure and is reflected, the reflection direction has components in both the horizontal direction and the upward direction, and the directions of the horizontal components corresponding to the first surface and the second surface are opposite. Therefore, the light incident on the first light guide microstructure can be reflected by the first light guide microstructure in a manner that reflects toward the light-emitting surface and is dispersed to both sides in the horizontal direction, thereby improving the uneven brightness phenomenon at the light-incident position of the backlight module. On the other hand, when the light strikes the curved third surface of the second light guide microstructure, the light can be evenly scattered and guided to the light-emitting surface through reflection or refraction, improving the light-emitting quality of the light guide plate, enabling the light guide plate to be applied to the backlight module with a 1P1D ultra-thin structure.

[0062] According to the light guide plate provided in the second aspect of the present application, based on the imaginary planes corresponding to the third light guiding microstructures and the fourth light guiding microstructures having acute angles with the light incident surface that are equal in magnitude and opposite in direction, and the fourth surfaces of the third light guiding microstructures and the fourth light guiding microstructures being formed as planes that extend obliquely with respect to the bottom surface in a manner that the farther away from the bottom surface, the closer to the fifth surface. Therefore, when the light emitted by the light source hits the fourth surfaces of the third light guiding microstructures and the fourth light guiding microstructures, it is reflected. The reflection direction has components both in the horizontal direction and in the upward direction, and the directions of the horizontal components corresponding to the third light guiding microstructures and the fourth light guiding microstructures are opposite. Therefore, the light hitting the third light guiding microstructures and the fourth light guiding microstructures can be reflected by the two in a manner that reflects towards the light emitting surface and is dispersed to both sides in the horizontal direction, thereby improving the uneven brightness phenomenon of the backlight module. On the other hand, when the light hits the fifth surface with a curved surface configuration of the fifth light guiding microstructure, the light can be evenly scattered and guided to the light emitting surface through reflection or refraction, improving the light output quality of the light guide plate, enabling the light guide plate to be applied to the backlight module with a 1P1D ultra-thin structure.

[0063] According to the manufacturing method of the light guide plate provided in the present application, a master plate with pits corresponding to the positions and shapes of different light guiding microstructures of the light guide plate can be produced using the same ejector pin, and after uniformly punching pits of the same configuration, the pits of another configuration can be formed uniformly. In this way, it not only helps to simplify the manufacturing process of the light guide plate and improve the manufacturing efficiency of the light guide plate, but also helps to save the procurement cost of the ejector pin. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present application and do not limit the present application.

[0065] Figure 1 It is a side view schematic diagram of the backlight module provided by the embodiment of the present application.

[0066] Figure 2 It is a side view schematic diagram of the backlight module provided by the embodiment of the present application.

[0067] Figure 3 It is a side view schematic diagram of the backlight module provided by the embodiment of the present application.

[0068] Figure 4 It is a top view schematic diagram of the light source and the light guide plate provided by the embodiment of the present application.

[0069] Figure 5 It is a schematic diagram of the light propagation in the light guide plate provided by the embodiment of the present application.

[0070] Figure 6 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0071] Figure 7 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0072] Figure 8 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0073] Figure 9 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0074] Figure 10 It is a top view schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0075] Figure 11 It is a cross-sectional schematic diagram of the light guide microstructure at a hypothetical plane provided by an embodiment of the present application.

[0076] Figure 12 It is a top view schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0077] Figure 13 It is a flowchart of the manufacturing method of the light guide plate provided by an embodiment of the present application.

[0078] Figure 14 It is a top view schematic diagram of the light source and the light guide plate provided by an embodiment of the present application.

[0079] Figure 15 It is a schematic diagram of the light propagation in the light guide plate provided by an embodiment of the present application.

[0080] Figure 16 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0081] Figure 17 It is a three-dimensional schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0082] Figure 18 It is a top view schematic diagram of the light guide microstructure provided by an embodiment of the present application.

[0083] Figure 19 It is a cross-sectional schematic diagram of the light guide microstructure at a hypothetical plane provided by an embodiment of the present application.

[0084] Figure 20 It is a flowchart of the manufacturing method of the light guide plate provided by an embodiment of the present application.

[0085] Figure 21 It is the simulation result of the light propagation at the light incident position of a light guide plate without a conventional light guide plate.

[0086] Figure 22It is the simulation result of the light propagation at the light incident position of the light guide plate provided by the embodiment of the present application, where θ1 = 90°, ε1 = 36°, and ε2 = 30°.

[0087] Figure 23 is Figure 21 the actual effect of the conventional light guide plate at the light incident position in

[0088] Figure 24 is Figure 22 the actual effect of the light guide plate at the light incident position in

[0089] Figure 25 is Figure 21 the horizontal field angle distribution of the outgoing light of the conventional light guide plate in

[0090] Figure 26 is Figure 22 the horizontal field angle distribution of the outgoing light of the light guide plate in

[0091] Figure 27 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 60°, ε1 = 36°, and ε2 = 30°.

[0092] Figure 28 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 120°, ε1 = 36°, and ε2 = 30°.

[0093] Figure 29 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 180°, ε1 = 36°, and ε2 = 30°.

[0094] Figure 30 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 210°, ε1 = 36°, and ε2 = 30°.

[0095] Figure 31 It is the expanded comparison of the horizontal field angles of the outgoing lights of various light guide plates provided by the embodiments of the present application and the conventional laser dot light guide plate.

[0096] Figure 32 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 110°, ε2 = 30°, and ε1 = 20°.

[0097] Figure 33 It is the horizontal field angle distribution of the outgoing light of the light guide plate provided by the embodiment of the present application, where θ1 = 110°, ε2 = 30°, and ε1 = 30°.

[0098] Figure 34 It is the angular distribution of the outgoing light of the light guide plate provided by the embodiment of the present application in the horizontal direction, where θ1 = 110°, ε2 = 30°, and ε1 = 40°.

[0099] Explanation of reference numerals:

[0100] DRH - Horizontal direction, DRV - Vertical direction;

[0101] VF, VF' - Hypothetical planes;

[0102] ABD - First surface, ACD - Second surface, BCDE - Third surface;

[0103] B'C'D' - Fourth surface, B'C'D'E' - Fifth surface;

[0104] 1 - Light source;

[0105] 2 - Light guide plate, 2a - Light incident surface, 2b - Bottom surface, 2b1 - First region, 2b2 - Second region, 2b3 - Third region, 2b4 - Fourth region outgoing surface, 2c - Outgoing surface, 20 - Light guide microstructure, 21 - First light guide microstructure, 22 - Second light guide microstructure, 23 - Third light guide microstructure, 24 - Fourth light guide microstructure, 25 - Fifth light guide microstructure;

[0106] 3 - Reflective sheet;

[0107] 4 - Prismatic sheet;

[0108] 5 - Diffusion sheet;

[0109] 6 - Additional diffusion sheet;

[0110] 7 - Additional prismatic sheet. Detailed implementation manners

[0111] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are some, rather than all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present application without creative efforts fall within the scope of protection of the present application. It can be understood that, without conflict, some technical means described in the various embodiments herein may be replaced or combined with each other.

[0112] In the description of the present application, if there are terms such as "first" and "second", they are only used to distinguish the described objects and do not have any sequential or technical meanings. Thus, the objects defined with "first", "second", etc. may explicitly or implicitly include one or more of such objects. Moreover, for example, the term "first element" itself does not imply the existence of a "second element", and the term "second element" itself does not imply the existence of a "first element". In addition, similar words such as "a" or "one" do not indicate a quantity limitation but indicate the existence of at least one, and "a plurality" means not less than two.

[0113] In the description of the present application, the terms "comprise" and "have" indicate the existence of the described features, numbers, operations, elements, and / or combinations thereof, but do not exclude the existence or addition of one or more other features, numbers, operations, elements, and / or combinations thereof.

[0114] In the description of the present application, reference to "an embodiment" or "some embodiments" etc. means that in one or more embodiments of the present application, the specific features, structures, or characteristics described in connection with that embodiment are included. Thus, statements such as "in an embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0115] Figures 1 to 3 The backlight module provided by some embodiments of the present application is shown. The backlight modules in these embodiments all include a light source 1, a light guide plate 2, a reflector 3, a prism sheet 4, and a diffusion sheet 5.

[0116] The light source 1 can be an LED (light-emitting diode), which can generate light rays that are incident on the following incident surface 2a of the light guide plate 2 under the drive of electric power. In the present embodiment, the light source 1 is a side-in type light source 1, which is arranged on the side of the incident surface 2a of the light guide plate 2.

[0117] The light guide plate 2 includes an incident surface 2a, an exit surface 2c, and a bottom surface 2b. The exit surface 2c and the bottom surface 2b are opposed to each other in the thickness direction of the light guide plate 2, and a plurality of light guiding microstructures 20 are formed on the bottom surface 2b. The light guiding microstructures 20 can guide the light rays incident on it to obtain an ideal light output quality on the exit surface 2c of the light guide plate 2. The incident surface 2a is connected to the two on one side of the exit surface 2c and the bottom surface 2b, and is formed into a narrow long rectangle.

[0118] The prism sheet 4 and the reflective sheet 3 are respectively disposed on opposite sides of the light guide plate 2 in the thickness direction. Specifically, the prism sheet 4 is disposed on the light-emitting surface 2c side of the light guide plate 2, while the reflective sheet 3 is disposed on the bottom surface 2b side of the light guide plate 2. The light emitted from the light source 1 and directed toward the light-incident surface 2a is guided by the light guide plate 2 and most of it is directly emitted from the light-emitting surface 2c. A small part of the light inevitably leaks out from the bottom surface 2b of the light guide plate 2. The light that leaks out from the bottom surface 2b of the light guide plate 2 is reflected by the reflective sheet 3 and then returns from the bottom surface 2b into the light guide plate 2 again and is emitted from the light-emitting surface 2c and directed directly or through other intermediate elements (such as the additional diffusion sheet 6 described later) toward the prism sheet 4. In this way, the amount of light directed toward the prism sheet 4 can be increased, thereby improving the light-emitting efficiency of the backlight module.

[0119] The diffusion sheet 5 is disposed on the side of the prism sheet 4 away from the light guide plate 2, and is used to receive the light emitted from the prism sheet 4 and diffuse the light before emitting it.

[0120] In some other embodiments, the proportion of the light leaking out from the bottom surface 2b of the light guide plate 2 is extremely small, or, considering cost savings in manufacturing and reducing the overall thickness of the module, the reflective sheet 3 can be omitted.

[0121] The prism sheet 4 can adjust the light. It includes a plurality of prism units arranged in sequence in the direction perpendicular to the aforementioned light-incident surface 2a, that is, the vertical direction DRV. Each prism unit extends in a long strip shape in the horizontal direction DRH parallel to the light-incident surface 2a, and the cross-section of the prism unit can be triangular, and in particular, it can be an isosceles triangle.

[0122] In Figure 1 the illustrated embodiment, the backlight module has a 1P1D architecture, which has only one diffusion sheet 5 and only one prism sheet 4.

[0123] In Figure 2 the illustrated embodiment, the backlight module has a 1P2D architecture. In addition to the aforementioned diffusion sheet 5 and prism sheet 4, it further has an additional diffusion sheet 6, which is disposed between the prism sheet 4 and the light guide plate 2 to receive the light emitted from the light guide plate 2 and diffuse the light before directing it toward the prism sheet 4. The additional diffusion sheet 6 and the diffusion sheet 5 can have the same or different structures.

[0124] In Figure 3 the illustrated embodiment, the backlight module has a 2P1D architecture. In addition to the aforementioned diffusion sheet 5 and prism sheet 4, it further has an additional prism sheet 7. The diffusion sheet 5 is disposed between the aforementioned prism sheet 4 and the light guide plate 2 to receive the light emitted from the light guide plate 2 and guide the light before directing it toward the prism sheet 4. The additional prism sheet 7 and the prism sheet 4 can have the same or different structures.

[0125] Hereinafter, the light guide plate 2 involved in each embodiment of the present application will be described in detail, especially the plurality of light guide microstructures 20 formed on the bottom surface 2b of the light guide plate 2 described above.

[0126] First, please refer to Figures 4 to 12 and in combination with Figures 1 to 3 , where Figures 6 to 9 shows the light guide microstructures 20 formed on the bottom surface 2b of the light guide plate 2 provided in some embodiments of the present application, and Figure 4 shows the arrangement of the light guide microstructures 20 on the bottom surface 2b of the light guide plate 2 in these embodiments. Figure 5 Schematically shows the light path of light passing through the light guide plate 2 of one of the embodiments. In these embodiments, the shapes of the light guide microstructures 20 are all formed to be symmetric about their respective imaginary planes VF, which are perpendicular to the bottom surface 2b and the light incident surface 2a of the light guide plate 2. And, the light guide microstructures 20 have a first surface ABD, a second surface ACD, and a third surface BCDE adjacent to each other. Among them, the first surface ABD and the second surface ACD are formed as two non-coplanar planes symmetrically arranged on both sides of the imaginary plane VF, while the third surface BCDE is formed as a curved surface that is symmetric about the imaginary plane and protrudes in a direction away from the first surface ABD and the second surface ACD. And, the first surface ABD and the second surface ACD have a first common side AD located in the imaginary plane, and the first common side AD extends obliquely with respect to the bottom surface 2b in such a way that it gets closer to the third surface BCDE as it gets farther away from the bottom surface 2b. Obviously, the first common side AD is a straight edge. In addition, the first surface ABD and the third surface BCDE have a second common side BD, the second surface ACD and the third surface BCDE have a third common side CD, the second common side BD and the third common side CD are symmetrically located on both sides of the imaginary plane VF, and the first common side AD, the second common side BD, and the third common side CD have a common intersection point D.

[0127] The second common side BD and the third common side CD can be curved edges with a certain degree of curvature. In this case, both the first surface ABD and the second surface ACD are triangles with one curved edge and two straight edges. In addition, the second common side BD and the third common side CD can also be straight edges. In this case, the first surface ABD and the second surface ACD are triangles.

[0128] The third surface BCDE can be a quadratic surface, such as a part of a cylindrical surface, or a part of a conical surface, or a part of a spherical surface, or a part of an ellipsoidal surface, or a part of a parabolic surface. Exemplarily, Figure 8 the third surface BCDE in Figure 7 is a part of a cylindrical surface, Figure 6 andFigure 10 The third surface BCDE therein is a part of a conical surface, and in the case where the third surface BCDE is a part of the conical surface, the common intersection point D can be the vertex of the cone or a point on the conical surface below the cone vertex.

[0129] Each light guiding microstructure 20 is formed as a recess recessed from the bottom surface 2b, and the aforementioned first surface ABD, second surface ACD, and third surface BCDE are all inner surfaces (or inner wall surfaces) of the recess. The plurality of light guiding microstructures 20 includes a plurality of first light guiding microstructures 21 and a plurality of second light guiding microstructures 22. For each first light guiding microstructure 21, its first surface ABD and second surface ACD are closer to the light incident surface 2a than its third surface BCDE. For each second light guiding microstructure 22, its first surface ABD and second surface ACD are farther from the light incident surface 2a than its third surface BCDE. That is, the first light guiding microstructures 21 and the second light guiding microstructures 22 are arranged on the bottom surface 2b of the light guide plate 2 with different angular orientations. The first light guiding microstructures 21 are configured with the first surface ABD and the second surface ACD in a planar configuration as the light-facing surfaces, and the second light guiding microstructures 22 are configured with the third surface BCDE in a curved surface configuration as the light-facing surface. Thus, please refer to Figure 4 and Figure 5 , when the light rays emitted by the light source 1 are incident on the first surface ABD and the second surface ACD of the first light guiding microstructure 21, they are reflected, and the reflection direction has components both in the long side direction parallel to the light incident surface 2a, that is, the horizontal direction DRH, and in the upward direction. Moreover, the directions of the horizontal components corresponding to the first surface ABD and the second surface ACD are opposite. Therefore, on the one hand, the light rays incident on the first light guiding microstructure 21 can be reflected by the first light guiding microstructure 21 in a manner of being reflected towards the light exit surface 2c and dispersed to both sides in the horizontal direction DRH, thereby improving the uneven brightness phenomenon of the backlight module; on the other hand, when the light rays are incident on the third surface BCDE with a curved surface configuration of the second light guiding microstructure 22, the light rays can be preferably evenly scattered and guided to the light exit surface 2c through refraction or reflection, improving the light output quality of the light guide plate 2.

[0130] Please recall Figure 4, the bottom surface 2b includes a first region 2b1 and a second region 2b2. The first region 2b1 is adjacent to the light incident surface 2a, and the second region 2b2 is adjacent to the first region 2b1 on the side opposite to the light incident surface 2a of the first region 2b1. All of the aforementioned plurality of first light guiding microstructures 21 are arranged in the first region 2b1, and most of the aforementioned plurality of second light guiding microstructures 22 are arranged in the second region 2b2, and a small part of the second light guiding microstructures 22 are arranged in the first region 2b1. This is because, in a side-in type backlight module, the phenomenon of uneven brightness usually occurs on the side of the light guide plate 2 close to the light source 1. Due to the relatively large arrangement pitch of the LED light sources, such as Pitch = 8mm, within a relatively small propagation distance, such as A = 4mm, it is difficult for light to directly propagate between the LEDs. Therefore, there is a dark area between the LEDs on the side of the light guide plate 2 close to the light source 1. In the embodiment of the present application, the first light guiding microstructures 21 are arranged in the first region 2b1 close to the light incident surface 2a, so as to specifically make the light propagate to the dark area between the LEDs at this position, improve the brightness of the dark area, and thus contribute to improving the light output uniformity of the light guide plate 2 and the optical quality of the picture.

[0131] Please refer to again Figure 4 , generally, the light guiding microstructures 20 in the first region 2b1 can be arranged as follows: in the first region 2b1, in the direction away from the light incident surface 2a, the proportion of the number of the second light guiding microstructures 22 increases.

[0132] It should be noted that another part of the aforementioned plurality of light guiding microstructures 20 can also be arranged on the bottom surface 2b at other angular orientations, such as 45° (that is, the included angle between the imaginary plane and the light incident surface 2a is 45°). In addition, additional light guiding microstructures with other shapes, such as hemispherical or circular laser dots, can also be formed on the bottom surface 2b of the light guide plate 2. The embodiment of the present application does not make specific limitations on this. However, in the case where there are light guiding microstructures with other shapes or angular orientations on the bottom surface 2b of the light guide plate 2, it is preferred that the proportion of the number of the first light guiding microstructures 21 and the second light guiding microstructures 22 (the sum of the two) is more than 80%.

[0133] Please refer to Figure 10 and Figure 12 , the outer contour of the projection of each light guiding microstructure 20 on the bottom surface 2b has an included angle θ1 (i.e., ∠BAC) defined by a first surface ABD and a second surface ACD. The size of this included angle θ1 will affect the light output quality of the light guide plate 2. The inventor found that when 60° ≤ θ1 ≤ 210°, the light output quality of the light guide plate 2 is better. In addition, since the first surface ABD and the second surface ACD are not coplanar, θ1 ≠ 180°. Figure 10 shows the case where θ1 < 180°, while Figure 12 shows the case where θ1 > 180°.

[0134] Please refer to Figure 11 , in some embodiments, the cross-section of the light guide microstructure 20 (including the first light guide microstructure 21 and the second light guide microstructure 22) in their respective corresponding imaginary planes can be a triangle. The triangle has a first base angle ε1 (i.e., ∠DAE) corresponding to the first common side AD and a second base angle ε2 (i.e., ∠DEA) corresponding to the third surface BCDE. The inventors have found that when 16° ≤ ε1 ≤ 40° and 19° ≤ ε2 ≤ 37°, and particularly preferably when 24° ≤ ε1 ≤ 40° and 23° ≤ ε2 ≤ 31°, on the one hand, it is possible to easily make the light-emitting surface 2c of the light guide plate 2 emit light at an ideal angle, and thus it is easy to make the backlight module of the 1P1D architecture emit light at a substantially 0° angle. On the other hand, at least most of the light rays incident on the first surface ABD and the second surface ACD of the first light guide microstructure 21 can be directly emitted from the light-emitting surface 2c of the light guide plate 2 after being reflected once from the first surface ABD and the second surface ACD (i.e., total internal reflection does not occur at the light-emitting surface 2c). The distance between the emission position of this part of the light rays on the light-emitting surface 2c and the light-incident surface 2c (the distance in the vertical direction DRV) is short, which helps to further improve the light guide efficiency at the light-incident port of the light guide plate 2, better ensure the brightness at the light-incident port of the light guide plate 2 and meet the requirements of the low A value of the backlight module. On the other hand, the propagation direction of the light rays reflected by the first surface ABD and the second surface ACD also has a component away from the light-incident surface 2a, so that the light rays propagate forward, which helps to improve the light emission uniformity of the light guide plate 2. When ε1 is less than 16° and / or ε2 is less than 19°, the light-emitting angle of the light guide plate 2 is too large, and when ε1 is greater than 40° and / or ε2 is greater than 37°, the light-emitting angle of the light guide plate 2 is too small, and neither can well match the backlight structure of 1P1D. In addition, when ε1 is less than 16°, when the light rays incident on the first surface ABD and the second surface ACD of the first light guide microstructure 21 are reflected and then incident on the light-emitting surface 2c, total internal reflection will occur at the light-emitting surface 2c due to the incident angle being greater than the total internal reflection angle, and the light rays will be reflected back into the light guide plate 2 and continue to propagate forward until they are incident on the light guide microstructure again or multiple times and are emitted from the light-emitting surface after reflection. At this time, the emission position of the light rays is far from the light-incident surface (the forward propagation distance of the light rays in the vertical direction DRV at the light-incident port of the light guide plate is long), which is not conducive to meeting the requirement of the low A value of the light guide plate 2. It should be noted that since the light guide microstructure 20 on the light guide plate 2 is usually fabricated by hot embossing using a mold, and during hot embossing, due to a series of factors such as the rebound of the material, the transfer efficiency is about 50% - 60%. Therefore, when these light guide microstructures 20 are transferred to the light guide plate 2, their external shapes and morphologies change, and the aforementioned cross-section in the imaginary plane is difficult to be a strict triangle. Therefore, in the description of the present application, these angle values mentioned are generally determined based on the angles between the closest straight lines.

[0135] The above conclusion is drawn by the inventor based on theoretical calculations and optical simulation analysis, and experimental verification has been carried out. A part of the theoretical calculation process is briefly given below.

[0136] For Figure 1 the backlight module with the 1P1D architecture shown, when the refractive index n of its prism sheet 4 satisfies 1.49 ≤ n ≤ 1.61 (this is the typical value range of the refractive index of the prism sheet), the peak light output angle Φ1 of the light guide plate 2 is usually required to be between 20° and 50°, so that the backlight module can easily emit light at about 0°. If the light guide microstructures 20 are arranged as Figure 4 shown or in a similar manner, it can be known from theoretical simulation that the relationship between the second base angle ε2 and the peak light output angle Φ1 of the light guide plate 2 is as shown in Table 1 below.

[0137] Table 1:

[0138] ε2 (°) Light-emitting peak angle Φ1 (°) of the light guide plate 17 52.3 19 45.8 21 44.6 23 40.1 25 39.5 27 38.3 29 32.9 31 30.2 33 27.5 35 23.9 37 19.4 39 15.8 41 13.1

[0139] It can be seen from Table 1 that when the second base angle ε2 satisfies 19° ≤ ε2 ≤ 37°, the corresponding Φ1 meets the light output angle requirement of the IPID architecture of the backlight module, that is, after passing through only one layer of prism sheet and diffusion sheet, the peak light output angle is about 0°. In addition, since the refractive index of the commonly used prism sheet on the market is a certain value between n = 1.51 and n = 1.61, when the peak light output angle of the corresponding light guide plate is between 30° - 40°, the peak light output angle of the 1P1D architecture backlight module can be better made to emit light at 0°. Therefore, 23° ≤ ε2 ≤ 31° is preferred.

[0140] In addition, in a small range near the light input port of the light guide plate, mainly the first light guide microstructures 21 are arranged. The angle between the light-facing surface of the light guide microstructure at this position and the bottom surface 2a is the first base angle ε1. Therefore, the value of ε1 will directly determine the optical performance at the light input port of the light guide plate 20. Under the taste requirements of eliminating the shadow between lamps and the bright spot in front of the lamp, and also meeting the module structure of 1P1D, the viewing angle of the backlight module is uniform within the entire viewing range. However, since it only appears in a very small range of the light input port, a slight difference in the viewing angle also meets the use requirements. Therefore, the requirement for the light output angle of the light guide plate at this place can be appropriately relaxed, for example, each is relaxed by 5°, so 15° ≤ Φ1 ≤ 55°. In this regard, the inventor also simulated and calculated the relationship between the value of ε1 and the light output angle of the light guide plate when θ1 = 110° and ε2 = 30°. The results are shown in Table 2 below.

[0141] Table 2:

[0142] ε1 (°) Light-emitting peak angle Φ1 (°) of the light guide plate 14 58.6 16 53.8 18 49.0 20 46.4 22 42.7 24 40.0 26 38.3 28 34.7 30 31.0 32 29.5 34 25.7 36 22.0 38 18.5 40 16.7 42 14.3

[0143] As can be seen from Table 2, when 16° ≤ ε1 ≤ 40°, 15° ≤ Φ1 ≤ 55° can be achieved, meeting the requirements of the IPID architecture. Please refer to Figure 13 , and an embodiment of the present application further provides a method for manufacturing the above light guide plate 2, the method comprising:

[0144] S1301, providing a punch, the punch having a shape complementary to the light guide microstructure 20.

[0145] Exemplarily, the punch can be formed into an elongated shape and have a head (also referred to as a cutting head) at one end with a shape complementary to the light guide microstructure 20, that is, the head of the punch has surfaces corresponding to the first surface ABD, the second surface ACD, and the third surface BCDE of the light guide microstructure 20 respectively. Additionally, the punch has high hardness and wear resistance.

[0146] S1302, causing the punch to impact multiple positions of the master plate at a first angle, thereby forming multiple first pits on the master plate corresponding to the multiple first light guide microstructures 21 respectively.

[0147] S1303, causing the punch to impact multiple other positions of the master plate at a second angle, thereby forming multiple second pits on the master plate corresponding to the multiple second light guide microstructures 22 respectively, wherein the first angle and the second angle are both angles of the punch around the impact direction, and the first angle is different from the second angle.

[0148] For example, in the initial state, the punch can be installed on the impact point device in a manner that its head extends outward and at a first angle, which is the angle of the punch around the impact direction, that is, the angle around the axis of the punch itself. Then, the impact point device drives the punch to move along the impact direction (which is also the axis extension direction of the punch itself) and successively impact multiple positions of the master plate, thereby forming multiple first pits on the master plate, and the shapes and relative positions of the multiple first pits correspond to the shapes and relative positions of the multiple first light guide microstructures 21.

[0149] After that, adjust the installation angle of the punch on the impact point device. For example, rotate the punch 180° around its own axis relative to the first angle to become the second angle. Subsequently, the impact point device drives the punch to successively impact multiple other positions of the master plate, thereby forming multiple second pits on the master plate, and the shapes and relative positions of the multiple second pits correspond to the shapes and relative positions of the multiple second light guide microstructures 22.

[0150] S1304, transferring the first pits and the second pits of the master plate to the mold core through a plate - turning process, thereby forming multiple first protrusions on the mold core that are complementary in shape and corresponding in position to the multiple first light guide microstructures 21, and multiple second protrusions that are complementary in shape and corresponding in position to the multiple second light guide microstructures 22.

[0151] S1305, use a mold core with a first protrusion and a second protrusion to emboss and manufacture a light guide plate 2.

[0152] Since it is a well-known technology in the art to manufacture a mold core by using a copying process and to manufacture a light guide plate 2 by embossing with the mold core, it will not be elaborated herein.

[0153] It should be understood that in various embodiments of the present application, the execution order of each step should be determined according to its function and internal logic. The size of each step number does not mean the sequence of execution, and it does not constitute any limitation to the implementation process of the embodiment. For example, the aforementioned step S1302 may be performed before step S1303 or after step S1303. The present application does not make any limitation in this regard, but step S1304 needs to be performed after steps S1302 and S1303.

[0154] According to the manufacturing method of the light guide plate 2 provided by the embodiments of the present application, a master plate with pits corresponding in position and shape to different light guide microstructures 20 (a first light guide microstructure 21 and a second light guide microstructure 22) of the light guide plate 2 can be manufactured by using the same ejector pin. Moreover, after all the first pits are uniformly punched out, the second pits can be formed uniformly, which helps to simplify the manufacturing process of the light guide plate 2 and improve the manufacturing efficiency of the light guide plate 2, and also helps to save the procurement cost of the ejector pin.

[0155] Next, please refer to Figures 14 to 19 and in combination with Figures 1 to 3 , Figures 16 to 17 shows the light guide microstructures 20 formed on the bottom surface 2b of the light guide plate 2 provided by some other embodiments of the present application, and Figure 15 shows the arrangement of the light guide microstructures 20 on the bottom surface 2b of the light guide plate 2 in these embodiments. Figure 15Schematically shows the optical path of light passing through the light guide plate 2 of one of the embodiments. In these embodiments, the shapes of the light guiding microstructures 20 are all formed to be symmetric about their respective imaginary planes VF', which are perpendicular to the bottom surface 2b. The light guiding microstructure 20 has a fourth surface B'C'D' and a fifth surface B'C'D'E' adjacent to each other. The fifth surface B'C'D'E' is formed as a curved surface that is symmetric about the imaginary plane and protrudes in a direction away from the fourth surface B'C'D'. The fourth surface B'C'D' is formed as a plane that extends obliquely with respect to the bottom surface 2b in such a way that it gets closer to the fifth surface B'C'D'E' as it is farther from the bottom surface 2b. Moreover, the plurality of light guiding microstructures 20 includes a plurality of third light guiding microstructures 23, a plurality of fourth light guiding microstructures 24, and a plurality of fifth light guiding microstructures 25. The imaginary plane VF' corresponding to the third light guiding microstructure 23 has an acute angle x1 with the light incident surface 2a, the imaginary plane VF' corresponding to the fourth light guiding microstructure 24 has an acute angle x2 with the light incident surface 2a that is equal in magnitude but opposite in direction to the angle x1, and the imaginary plane VF' corresponding to the fifth light guiding microstructure 25 is perpendicular to the light incident surface 2a. Exemplarily, x1 and x2 can be angles not less than 30°, so 30° ≤ x1 = x2 < 90°.

[0156] Each light guiding microstructure 20 is formed as a recess that is recessed from the bottom surface 2b, and both the fourth surface B'C'D' and the fifth surface B'C'D'E' are inner surfaces (or inner wall surfaces) of the recess. For each third light guiding microstructure 23 and each third light guiding microstructure 23, the corresponding imaginary plane VF' sequentially passes through the fourth surface B'C'D' and the fifth surface B'C'D'E' in a direction away from the light incident surface 2a. Therefore, the fourth surface B'C'D' is closer to the light incident surface 2a than the fifth surface B'C'D'E'; while for each fifth light guiding microstructure 25, the corresponding imaginary plane VF' sequentially passes through the fifth surface B'C'D'E' and the fourth surface B'C'D' in a direction away from the light incident surface 2a. Therefore, the fourth surface B'C'D' is farther from the light incident surface 2a than the fifth surface B'C'D'E'.

[0157] In this way, when the light rays emitted by the light source 1 strike the fourth surface B'C'D' of the third light guide microstructure 23 and the fourth surface B'C'D' of the fourth light guide microstructure 24, they are reflected. The reflection direction has components both in the long side direction of the incident light surface 2a, i.e., the horizontal direction DRH, and in the upward direction. Moreover, the directions of the horizontal components corresponding to the third light guide microstructure 23 and the fourth light guide microstructure 24 are opposite. Therefore, the light rays incident on the third light guide microstructure 23 and the fourth light guide microstructure 24 can be reflected by the two in a manner of reflecting towards the light-emitting surface 2c and dispersed to both sides in the horizontal direction DRH, thereby improving the uneven brightness phenomenon of the backlight module. On the other hand, when the light rays strike the fifth surface B'C'D'E' with a curved surface configuration of the fifth light guide microstructure 25, the light rays can be evenly scattered and guided to the light-emitting surface 2c through refraction or reflection preferably, improving the light-emitting quality of the light guide plate 2.

[0158] The fifth surface B'C'D'E' is similar to the aforementioned third surface BCDE. It can be a quadratic surface, such as a part of a cylindrical surface, or a part of a conical surface, or a part of a spherical surface, or a part of an ellipsoidal surface, or a part of a parabolic surface. Exemplarily, Figure 17 the fifth surface B'C'D'E' in Figure 16 is a part of a spherical surface, and Figure 17 the fifth surface B'C'D'E' in

[0159] Please refer to Figure 14 , the bottom surface 2b includes a third region 2b3 and a fourth region. The third region 2b3 is adjacent to the incident light surface 2a, and the fourth region is adjacent to the third region 2b3 on the side opposite to the incident light surface 2a of the third region 2b3. All of the aforementioned multiple third light guide microstructures 23 and multiple fourth light guide microstructures 24 are arranged in the third region 2b3, and most of the aforementioned multiple fifth light guide microstructures 25 are arranged in the fourth region, and a small part of the fifth light guide microstructures 25 are arranged in the third region 2b3. As described above, in the side-entry backlight module, the uneven brightness phenomenon usually occurs on the side of the light guide plate 2 close to the light source 1. There is an inter-LED dark area on the side of the light guide plate 2 close to the light source 1. In the embodiment of the present application, the third light guide microstructure 23 and the fourth light guide microstructure 24 are arranged in the third region 2b3 close to the incident light surface 2a, so as to specifically make the light rays propagate to the inter-LED dark area at this position, improve the brightness of the dark area, and further improve the light-emitting uniformity of the light guide plate 2 and the optical quality of the picture.

[0160] Please refer to again Figure 14, Generally, the light guiding microstructures 20 in the third region 2b3 can be arranged as follows: in the third region 2b3, in the direction away from the light incident surface 2a, the proportion of the number of the fifth light guiding microstructures 25 increases.

[0161] Similar to the foregoing cases, in Figures 14 to 19 In each of the corresponding embodiments, a part of the light guiding microstructures 20 can also be arranged on the bottom surface 2b of the light guide plate 2 at other angular orientations. For example, the foregoing plurality of light guiding microstructures 20 further includes a plurality of sixth light guiding microstructures 20, and the imaginary plane VF' corresponding to the sixth light guiding microstructures 20 is not parallel to any of the imaginary planes VF' corresponding to the third light guiding microstructure 23, the fourth light guiding microstructure 24, and the fifth light guiding microstructure 25. In addition, additional light guiding microstructures having other shapes, such as hemispherical or circular laser dots, can be formed on the bottom surface 2b of the light guide plate 2. The embodiments of the present application do not make specific limitations thereto. However, when there are also light guiding microstructures 20 with other shapes or angular orientations on the bottom surface 2b of the light guide plate 2, it is preferred that the proportion of the number of the third light guiding microstructure 23, the fourth light guiding microstructure 24, and the fifth light guiding microstructure 25 (the sum of the three) is more than 80%.

[0162] Please refer to Figure 19 , In some embodiments, the cross-section of the light guiding microstructures 20 (including the third light guiding microstructure 23, the fourth light guiding microstructure 24, and the fifth light guiding microstructure 25) in their respective corresponding imaginary planes VF' can be a triangle, and the triangle has a third base angle ε3 (i.e., ∠D'A''E') corresponding to the fourth surface B'C'D' and a fourth base angle ε4 (i.e., ∠D'E'A'') corresponding to the fifth surface B'C'D'E'. Figures 4 to 12Similarly, in the case of the illustrated embodiment, the inventors found that when 16° ≤ ε3 ≤ 40° and 19° ≤ ε4 ≤ 37°, and more preferably 24° ≤ ε3 ≤ 40° and 23° ≤ ε4 ≤ 31°, on the one hand, the light-emitting surface 2c of the light guide plate 2 can easily emit light at an ideal angle, and then the backlight module with a 1P1D architecture can easily emit light at an approximately 0° angle. On the other hand, at least most of the light rays incident on the fourth surface B'C'D' of the third light guide microstructure 23 and the fourth light guide microstructure 24 can be directly emitted from the light-emitting surface 2c of the light guide plate 2 after being reflected once from the fourth surface B'C'D' (i.e., total internal reflection does not occur at the light-emitting surface 2c). The distance between the emission position of this part of the light rays on the light-emitting surface 2c and the light-incident surface 2c (the distance in the vertical direction DRV) is short, which helps to further improve the light guide efficiency at the light-incident port of the light guide plate and better ensure the brightness at the light-incident port of the light guide plate 2 and meet the requirements of the low A value of the backlight module. On the other hand, the propagation direction of the light rays reflected by the third light guide microstructure 23 and the fourth light guide microstructure 24 also has a component away from the light-incident surface 2a, so that the light rays propagate forward, which helps to improve the light emission uniformity of the light guide plate 2. When ε3 is less than 16° and / or ε4 is less than 19°, the light-emitting angle of the light guide plate 2 is too large, and when ε3 is greater than 40° and / or ε4 is greater than 37°, the light-emitting angle of the light guide plate 2 is too small, and neither can well match the backlight structure of 1P1D. In addition, when ε3 is less than 16°, when the light rays incident on the first surface ABD and the second surface ACD of the first light guide microstructure 21 are reflected and then incident on the light-emitting surface 2c, total internal reflection occurs because the incident angle is greater than the total internal reflection angle, and the light rays are refracted back into the light guide plate 2 and continue to propagate forward until they are incident on the light guide microstructure again or multiple times and are reflected and emitted from the light-emitting surface. At this time, the emission position of the light rays is far from the light-incident surface 2c (the forward propagation distance of the light rays in the vertical direction DRV at the light-incident port of the light guide plate is long), which is not conducive to meeting the requirement of the low A value of the light guide plate 2.

[0163] Please refer to Figure 20 , the embodiment of the present application also provides a method for manufacturing Figures 13 to 19 the light guide plate 2 in

[0164] S2001, provide a punch, and the punch has a shape complementary to the light guide microstructure 20.

[0165] Exemplarily, the punch can be formed into an elongated shape and has a head at one end with a shape complementary to the light guide microstructure 20, that is, the punch head has surfaces corresponding to the fourth surface B'C'D' and the fifth surface B'C'D'E' of the light guide microstructure 20 respectively. Moreover, the punch has high hardness and wear resistance.

[0166] S2002, strike multiple positions of the master template with the striker at a third angle, thereby forming multiple third pits on the master template corresponding to the multiple third light-guiding microstructures 23 respectively.

[0167] S2003, strike multiple other positions of the master template with the striker at a fourth angle, thereby forming multiple fourth pits on the master template corresponding to the multiple fourth light-guiding microstructures 24 respectively.

[0168] S2004, strike multiple other positions of the master template with the striker at a fifth angle, thereby forming multiple fifth pits on the master template corresponding to the multiple fifth light-guiding microstructures 25 respectively, where the third angle, the fourth angle, and the fifth angle are all angles of the striker around the impact direction, and the third angle, the fourth angle, and the fifth angle are different from each other.

[0169] For example, in the initial state, the striker can be installed on the impact point device in a way that its head extends outward and at a third angle, which is the angle of the striker around the impact direction, that is, the angle around the axis direction of the striker itself. Then, the impact point device drives the striker to move along the impact direction, which is also the axis extension direction of the striker itself, and successively strike multiple positions of the master template, thereby forming multiple third pits on the master template. The shapes and relative positions of the multiple third pits correspond to the shapes and relative positions of the multiple third light-guiding microstructures 23.

[0170] After that, adjust the installation angle of the striker on the impact point device. For example, rotate the striker 90° around its own axis relative to the third angle to become the fourth angle. Subsequently, the impact point device drives the striker to successively strike multiple other positions of the master template, thereby forming multiple fourth pits on the master template. The shapes and relative positions of the multiple fourth pits correspond to the shapes and relative positions of the multiple fourth light-guiding microstructures 24.

[0171] Then, adjust the installation angle of the striker on the impact point device again. For example, rotate the striker 315° relative to the fourth angle to become the fifth angle. Then, the impact point device drives the striker to successively strike multiple other positions of the master template, thereby forming multiple fifth pits on the master template. The shapes and relative positions of the multiple fifth pits correspond to the shapes and relative positions of the multiple fifth light-guiding microstructures 25.

[0172] S2005, transfer the third pits, fourth pits, and fifth pits on the master template to the mold core through the process of turning over the plate, thereby forming multiple third protrusions on the mold core that are complementary in shape and corresponding in position to the multiple third light-guiding microstructures 23, multiple fourth protrusions that are complementary in shape and corresponding in position to the multiple fourth light-guiding microstructures 24, and multiple fifth protrusions that are complementary in shape and corresponding in position to the multiple fifth light-guiding microstructures 25.

[0173] S2006, use the mold core with the third protrusions, fourth protrusions, and fifth protrusions to imprint and manufacture the light guide plate 2.

[0174] According to the manufacturing method of the light guide plate 2 provided by the embodiments of the present application, a master plate with pits corresponding in position and shape to different light guiding microstructures 20 (the third light guiding microstructure 23, the fourth light guiding microstructure 24, and the fifth light guiding microstructure 25) of the light guide plate 2 can be produced using the same ejector pin. Moreover, after all the third pits are uniformly punched out, the fourth pits can be formed uniformly, and then the fifth pits can be formed uniformly, which helps to simplify the manufacturing process of the light guide plate 2 and improve the manufacturing efficiency of the light guide plate 2, and also helps to save the procurement cost of the ejector pin.

[0175] Figure 21 The simulation result of the light propagation at the light incident position of a light guide plate without the aforementioned configured light guiding microstructure 20 (but with a conventional laser dot microstructure) is shown, and Figure 23 the actual effect at the light incident position of this conventional light guide plate is shown, Figure 25 and the field angle distribution of the outgoing light of this conventional light guide plate in the horizontal direction DRH is shown. Figure 22 The simulation result of the light propagation at the light incident position of the light guide plate 2 in the embodiments of the present application is shown, and Figure 24 the actual effect at the light incident position of this light guide plate 2 is shown, Figure 26 and the field angle distribution of the outgoing light of this light guide plate 2 in the horizontal direction DRH is shown, where θ1 = 90°, ε1 = 36°, ε2 = 30°. By comparison, it can be known that the light guide plate 2 in the embodiments of the present application can reduce the bright spot problem in front of the LED lamp, and the light output quality of the light guide plate 2 is significantly improved. In addition, compared with the conventional light guide plate, the light guide plate 2 provided by the embodiments of the present application has a better broadening effect on the field angle in the horizontal direction DRH. Although Figure 22 and Figure 24 only the case of θ1 = 90°, ε1 = 36°, ε2 = 30° is shown, this is just an example given for simplicity of illustration. It should be understood that when other angular values are given to θ1, ε1 (ε3), and ε2 (ε4), especially when 60° ≤ θ1 ≤ 210° (θ1 can be 180°), 24° ≤ ε1 (or ε3) ≤ 40°, 23° ≤ ε2 (or ε4) ≤ 31°, similar optical effects can also be obtained as Figure 22 those.

[0176] Figures 27 to 30 The field angle distributions of the outgoing light of the light guide plate 2 in the embodiments of the present application in the horizontal direction DRH are shown respectively when the inner included angle θ1 is 60°, 120°, 180°, and 210°, where ε1 = 36°, ε2 = 30°. It can be understood that the case of θ1 being 180° corresponds to Figures 14 to 19In the illustrated embodiment, it can be seen that, compared with the conventional light guide plate, the light guide plate 2 provided in the embodiment of the present application has a better effect of broadening the viewing angle of DRH in the horizontal direction.

[0177] Figure 31 It shows in detail the comparison of the expansion of the outgoing light of the light guide plate 2 in the horizontal direction DRH viewing angle when the included angle θ1 takes different values. It can be seen that when 60° ≤ θ1 ≤ 210°, the full viewing angle half peak width of DRH in the horizontal direction is wider than that of the conventional laser dot pattern, and when the included angle θ1 is 90° and 120°, the expansion effect of DRH in the horizontal direction is better. In addition, it is found through testing that when θ1 is 100° and 110°, there is also a very good expansion effect of DRH in the horizontal direction.

[0178] Next, Figures 32 to 34 It shows the expansion of the light guide plate 2 on the horizontal direction DRH viewing angle of the light when ε1 is 20°, 30° and 40° respectively under the condition that θ1 = 110° and ε2 = 30°. It can be seen that the larger the value of ε1, the more beneficial it is to horizontally expand the light.

Claims

1. A light guide plate, comprising: The light emitting surface and the bottom surface are opposite to each other. a light incident surface connected to the light emitting surface and the bottom surface, and a plurality of light-guiding microstructures formed on the bottom surface; Characterized in that the shape of each of the light-guiding microstructures is formed to be symmetrical about a respective imaginary plane, the imaginary plane is perpendicular to the bottom surface and the light incident surface, each of the light-guiding microstructures has a first surface, a second surface, and a third surface adjacent to each other, the first surface and the second surface are formed as two non-coplanar planes symmetrically arranged on both sides of the imaginary plane, and the third surface is formed as a curved surface that is symmetrical about the imaginary plane and protrudes in a direction away from the first surface and the second surface; wherein the first surface and the second surface have a common edge located in the imaginary plane, and the common edge extends obliquely relative to the bottom surface in a manner that the further away from the bottom surface, the closer to the third surface; Each of the light-guiding microstructures is formed as a depression recessed from the bottom surface, and the multiple light-guiding microstructures include multiple first light-guiding microstructures and multiple second light-guiding microstructures, and the first light-guiding microstructures and the second light-guiding microstructures have the same shape; for each of the first light-guiding microstructures, the first surface and the second surface are closer to the light incident surface than the third surface; for each of the second light-guiding microstructures, the first surface and the second surface are farther away from the light incident surface than the third surface.

2. The light guide plate according to claim 1, characterized in that: The bottom surface comprises: A first area, which is adjacent to the light incident surface; a second region, which is adjacent to the first region on a side of the first region opposite to the light incident surface; The plurality of first light guide microstructures are all arranged in the first region, a portion of the plurality of second light guide microstructures are arranged in the first region, and another portion are arranged in the second region.

3. The light guide plate according to claim 1 or 2, characterized in that: The outer contour of the projection of the light-guiding microstructure on the bottom surface has an inner angle θ1 defined by the first surface and the second surface, and 60°≤θ1≤210°.

4. The light guide plate according to claim 3, characterized in that: The outer contour of the projection has an arc segment defined by the third surface, and the arc segment is connected to the inner angle so that the two constitute the entire outer contour.

5. The light guide plate according to claim 3, characterized in that: The third surface is formed as one of the following: a part of a cylindrical surface, a part of a conical surface, a part of a spherical surface, a part of an ellipsoidal surface, and a part of a parabola.

6. The light guide plate according to claim 3, characterized in that: The cross-section of each of the light-guiding microstructures in the imaginary plane is a triangle, and the triangle has a first base angle ε1 corresponding to the common edge and a second base angle ε2 corresponding to the third surface, 16°≤ε1≤40°, 19°≤ε2≤37°.

7. The light guide plate according to claim 6, characterized in that: ε1≥24°.

8. The light guide plate according to claim 6, characterized in that: The first surface, the second surface and the third surface constitute the entire inner surface of the recess, the first area is an area within 80 mm from the light incident surface, the second area is an area outside 80 mm from the light incident surface, θ1 is 90°, 100°, 110° or 120°, ε1 is 36°, and ε2 is 30°.

9. A light guide plate, comprising: The light emitting surface and the bottom surface are opposite to each other. a light incident surface connected to the light emitting surface and the bottom surface, and a plurality of light-guiding microstructures formed on the bottom surface; The invention is characterized in that the shape of each of the light-guiding microstructures is formed to be symmetrical about a respective imaginary plane, the imaginary plane is perpendicular to the bottom surface, each of the light-guiding microstructures has a fourth surface and a fifth surface adjacent to each other, the fifth surface is formed to be a curved surface symmetrical about the imaginary plane and protruding in a direction away from the fourth surface, and the fourth surface is formed to be a plane extending obliquely relative to the bottom surface in a manner that the farther away from the bottom surface, the closer to the fifth surface; Wherein, the plurality of light-guiding microstructures include a plurality of third light-guiding microstructures, a plurality of fourth light-guiding microstructures and a plurality of fifth light-guiding microstructures, and the third light-guiding microstructures, the fourth light-guiding microstructures and the fifth light-guiding microstructures have the same shape; The imaginary plane corresponding to the third light guiding microstructure has an acute angle x1 with the light incident surface, the imaginary plane corresponding to the fourth light guiding microstructure has an acute angle x2 with the light incident surface that is equal to the angle x1 but opposite in direction, and the imaginary plane corresponding to the fifth light guiding microstructure is perpendicular to the light incident surface; Each of the light-guiding microstructures is formed as a depression recessed from the bottom surface; for each of the third light-guiding microstructures and each of the fourth light-guiding microstructures, the corresponding imaginary plane passes through the fourth surface and the fifth surface in sequence in the direction away from the light incident surface; for each of the fifth light-guiding microstructures, the corresponding imaginary plane passes through the fifth surface and the fourth surface in sequence in the direction away from the light incident surface.

10. The light guide plate according to claim 9, characterized in that: x1≥30°。 11. The light guide plate according to claim 9, characterized in that: The bottom surface comprises: a third region, which is adjacent to the light incident surface; a fourth region, which is adjacent to the third region on a side of the third region opposite to the light incident surface; The plurality of third light-guiding microstructures and the plurality of fourth light-guiding microstructures are both arranged in the third region, a portion of the plurality of fifth light-guiding microstructures are arranged in the third region, and another portion are arranged in the fourth region.

12. The light guide plate according to any one of claims 9 to 11, characterized in that: The fifth surface is formed as one of the following: a part of a cylindrical surface, a part of a conical surface, a part of a spherical surface, a part of an ellipsoidal surface, and a part of a parabola.

13. The light guide plate according to any one of claims 9 to 11, characterized in that: The cross-section of each of the light-guiding microstructures in the imaginary plane is a triangle, and the triangle has a third base angle ε3 corresponding to the fourth surface and a fourth base angle ε4 corresponding to the fifth surface, 16°≤ε3≤40°, 19°≤ε4≤37°.

14. The light guide plate according to claim 13, characterized in that: ε3≥24°.

15. A backlight module, characterized in that: include: light source, and The light guide plate according to any one of claims 1 to 14; Wherein, the light source is arranged on the light incident surface side of the light guide plate, and is used for emitting light toward the light incident surface.

16. A method for manufacturing the light guide plate according to any one of claims 1 to 8, characterized in that: include: providing a striker having a shape complementary to the light-guiding microstructure; The striker strikes a plurality of positions of the master at a first angle, thereby forming a plurality of first pits on the master corresponding to the plurality of first light guide microstructures respectively; The striker strikes a plurality of other positions of the master at a second angle, thereby forming a plurality of second pits on the master corresponding to the plurality of second light-guiding microstructures, wherein the first angle and the second angle are both angles of the striker around the strike direction, and the first angle is different from the second angle; The first concave pit and the second concave pit of the master are transferred to the mold core by a reprinting process, so as to form a plurality of first protrusions complementary in shape to the plurality of first light guide microstructures and corresponding in position, and a plurality of second protrusions complementary in shape to the plurality of second light guide microstructures and corresponding in position on the mold core; The light guide plate is manufactured by embossing using the mold core having the first protrusion and the second protrusion.

17. A method for manufacturing a light guide plate as claimed in any one of claims 9 to 14, characterized in that: include: providing a striker having a shape complementary to the light-guiding microstructure; The striker strikes a plurality of positions of the master at a third angle, thereby forming a plurality of third pits on the master corresponding to the plurality of third light guide microstructures respectively; The striker strikes a plurality of other positions of the master at a fourth angle, thereby forming a plurality of fourth pits on the master corresponding to the plurality of fourth light guide microstructures respectively; The striker strikes a plurality of other positions of the master at a fifth angle, thereby forming a plurality of fifth pits on the master corresponding to the plurality of fifth light-guiding microstructures, wherein the third angle, the fourth angle, and the fifth angle are all angles of the striker around the striking direction, and the third angle, the fourth angle, and the fifth angle are different from each other; The third concave pit, the fourth concave pit and the fifth concave pit of the master are transferred to the mold core by a reprinting process, so as to form a plurality of third protrusions complementary in shape to the plurality of third light guide microstructures and corresponding in position, a plurality of fourth protrusions complementary in shape to the plurality of fourth light guide microstructures and corresponding in position, and a plurality of fifth protrusions complementary in shape to the plurality of fifth light guide microstructures and corresponding in position on the mold core; The light guide plate is manufactured by embossing using the mold core having the third protrusion, the fourth protrusion and the fifth protrusion.

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