阅读说明：本技术 一种导光板及背光源结构 (Light guide plate and backlight source structure ) 是由 马骏 薛九枝 于 2020-06-15 设计创作，主要内容包括：本发明公开了一种导光板,其具有入光面、出光面和反射面,入光面与出光面垂直并相邻,入光面位于靠近光源的一侧,反射面与出光面位置相对设置,反射面和出光面至少其一上具有多个凸型或凹型的网点微结构,网点微结构的表面上任一点的切线与反射面的接触角不大于7°。本发明还公开了包括上述导光板的背光源结构,背光源结构还包括光源；光线矫正膜,光线矫正膜位于导光板的出光面一侧,光线矫正膜背离导光板的一侧具有沿平行于入光面方向延伸并间断排布的多个微棱镜结构；反射片,反射片位于导光板的反射面一侧。本发明的导光板及背光源结构,有效提高光线利用率,增加正视方向显示亮度,降低背光模组厚度和成本。(The invention discloses a light guide plate, which is provided with a light inlet surface, a light outlet surface and a reflecting surface, wherein the light inlet surface is vertical to and adjacent to the light outlet surface, the light inlet surface is positioned at one side close to a light source, the reflecting surface and the light outlet surface are oppositely arranged, at least one of the reflecting surface and the light outlet surface is provided with a plurality of convex or concave lattice point microstructures, and the contact angle between the tangent line of any point on the surface of the lattice point microstructure and the reflecting surface is not more than 7 degrees. The invention also discloses a backlight source structure comprising the light guide plate, and the backlight source structure further comprises a light source; the light ray correcting film is positioned on one side of the light emitting surface of the light guide plate, and one side of the light ray correcting film, which is far away from the light guide plate, is provided with a plurality of micro-prism structures which extend in the direction parallel to the light incident surface and are arranged discontinuously; and the reflecting sheet is positioned on one side of the reflecting surface of the light guide plate. The light guide plate and the backlight source structure effectively improve the utilization rate of light rays, increase the display brightness in the front view direction and reduce the thickness and the cost of the backlight module.)

1. The light guide plate is characterized by comprising a light incident surface, a light emergent surface and a reflecting surface, wherein the light incident surface is vertical to and adjacent to the light emergent surface, the light incident surface is positioned on one side close to a light source, the reflecting surface is opposite to the light emergent surface, at least one of the reflecting surface and the light emergent surface is provided with a plurality of convex or concave lattice point microstructures, and the contact angle between the tangent line of any point on the surface of each lattice point microstructure and the reflecting surface is not more than 7 degrees.

2. The light guide plate according to claim 1, wherein the dot microstructures are pyramid structures, truncated pyramid structures, or arc-shaped structures.

3. The light guide plate according to claim 2, wherein the curved structures are one of partial spherical surfaces, ellipsoidal surfaces, or elliptic paraboloids, and projections of the curved structures on the reflective surface are circular or elliptical.

4. The light guide plate according to claim 3, wherein the diameter of the circle or the major axis of the ellipse is not greater than 130 μm in size.

5. A backlight structure comprising the light guide plate according to any one of claims 1 to 4, the backlight structure further comprising:

a light source;

the light ray correcting film is positioned on one side of the light emitting surface of the light guide plate, and one side of the light ray correcting film, which is far away from the light guide plate, is provided with a plurality of micro-prism structures which extend in the direction parallel to the light incident surface and are arranged discontinuously;

and the reflecting sheet is positioned on one side of the reflecting surface of the light guide plate.

6. The backlight structure of claim 5, wherein the cross section of the micro-prism structure along the direction perpendicular to the light incident surface is triangular, and the cross section of the micro-prism structure along the direction parallel to the light incident surface is trapezoidal.

7. The backlight structure of claim 6, wherein the triangle is an isosceles triangle, the trapezoid is an isosceles trapezoid, and the base angles of the isosceles triangle and the isosceles trapezoid are in the range of 65 ° -77 °.

8. The backlight structure as claimed in claim 7, wherein the length of the bottom side of the isosceles trapezoid is between 100 and 500 μm.

9. The backlight structure of claim 6, wherein the corners of the triangle are rounded corners having a radius of curvature of less than 5 microns, and the base of the triangle has a length of 18-40 microns.

10. The backlight structure of claim 5, wherein the plurality of microprism structures are arranged in a repeating pattern of adjacent and parallel prisms along a direction normal to the light-incident surface.

11. The backlight structure of claim 5, further comprising a diffuser on a side of the light correcting film facing away from the light guide plate.

Technical Field

The invention relates to the technical field of liquid crystal display backlight sources, in particular to a light guide plate and a backlight source structure.

Background

At present, the backlight mainly functions to form a uniform surface light source from linear light sources arranged on LEDs, and the optical assembly includes a light guide plate and various optical elements for adjusting and correcting light emitted from the light guide plate. In a conventional backlight structure, a structure such as a dot or a groove is usually added on the surface of a light guide plate to destroy the waveguide propagation of light (for example, a circular convex-concave type, a circular concave-concave type, a V-shaped groove and the like on the surface of the light guide plate), light emitted by the light guide plate is readjusted through a diffusion film, at this time, the horizontal/longitudinal light-emitting angle is increased, and finally, the light is shrunk through two layers of brightness enhancement films, and the final light-emitting angle is controlled within 70 degrees. However, the existing backlight has the following disadvantages: in the existing backlight structure, the light of the light guide plate has a large light-emitting angle after passing through the diffusion sheet and the brightness enhancement film, the large visual angle loss light accounts for more, the light utilization rate is low, and the front brightness is insufficient. On the other hand, the light-emitting angle of the existing backlight is not favorable for protecting the privacy of users, and for products with high brightness requirements and peep-proof requirements, the backlight with a small angle light-emitting range better meets the requirements, while the existing peep-proof means filters out light rays with a large viewing angle by adding an optical element, and the method is at the cost of sacrificing the backlight brightness. The traditional backlight source structure mainly comprises a light source, a light guide plate, a diffusion sheet, a lower brightness enhancement film, an upper brightness enhancement film and the like, has more optical elements and higher cost, and in addition, the traditional backlight source structure is lack of flexibility of light ray adjustment in the face of different light emitting distribution requirements.

Disclosure of Invention

The invention aims to provide a light guide plate and a backlight source structure aiming at the technical problems in the prior art, so that the light utilization rate is effectively improved, the display brightness in the front view direction is increased, and the thickness and the cost of a backlight module are reduced.

The invention adopts the following technical scheme:

the utility model provides a light guide plate, the light guide plate has income plain noodles, goes out plain noodles and plane of reflection, go into the plain noodles with it is perpendicular and adjacent to go out the plain noodles, go into the plain noodles and be located one side near the light source, the plane of reflection with go out the plain noodles position and set up relatively, the plane of reflection with go out at least one of them of plain noodles has a plurality of convex types or concave type dot micro-structures, the tangent line of any point on the surface of dot micro-structure with the contact angle of plane of reflection is not more than 7.

Preferably, the dot microstructure is a pyramid structure, a frustum structure or an arc surface structure.

Preferably, the arc structure is one of a partial spherical surface, an ellipsoid surface or an elliptic paraboloid surface, and a projection of the arc structure on the reflecting surface is a circle or an ellipse.

Preferably, the diameter of the circle or the major axis of the ellipse is no greater than 130 microns in size.

In another aspect, a backlight structure is provided, which includes any one of the light guide plates described above, and further includes: a light source; the light ray correcting film is positioned on one side of the light emitting surface of the light guide plate, and one side of the light ray correcting film, which is far away from the light guide plate, is provided with a plurality of micro-prism structures which extend in the direction parallel to the light incident surface and are arranged discontinuously; and the reflecting sheet is positioned on one side of the reflecting surface of the light guide plate.

Preferably, the cross section of the microprism structure along the direction perpendicular to the light incident surface is triangular, and the cross section of the microprism structure along the direction parallel to the light incident surface is trapezoidal.

Preferably, the triangle is an isosceles triangle, the trapezoid is an isosceles trapezoid, and the base angles of the isosceles triangle and the isosceles trapezoid are within the range of 65-77 degrees.

Preferably, the length of the bottom side of the isosceles trapezoid is between 100 and 500 micrometers.

Preferably, the vertex angle of the triangle is an arc chamfer, the curvature radius of the arc chamfer is less than 5 microns, and the length of the bottom edge of the triangle is 18-40 microns.

Preferably, the plurality of microprism structures are arranged adjacently and repeatedly in parallel along a direction perpendicular to the light incident surface.

Preferably, the light guide plate further comprises a diffusion sheet positioned on the side of the light ray correction film, which faces away from the light guide plate.

The light guide plate and the backlight source structure effectively improve the utilization rate of light rays, increase the display brightness in the front view direction and reduce the thickness and the cost of the backlight module.

Drawings

The invention may be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view illustrating a light guide plate and a backlight structure according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a dot microstructure with a pyramid structure on a reflective surface of a light guide plate in a backlight structure according to a first embodiment of the invention;

FIG. 3 is a schematic cross-sectional view of a possible microstructure of a lattice of pyramidal structures according to a first embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of a light-straightening film along a direction perpendicular to a light-incident surface according to a first embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of a light-straightening film along a direction parallel to a light-incident surface according to a first embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a microprism structure along a direction perpendicular to an incident surface according to a first embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view of a microprism structure of the first embodiment of the present invention taken along a direction perpendicular to the light incident surface;

FIG. 8 is a schematic cross-sectional view of a microprism structure along a direction parallel to the light incident surface in accordance with a first embodiment of the present invention;

FIG. 9 is a schematic cross-sectional view of a backlight structure according to a second embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a dot microstructure with a cambered surface structure on a reflective surface of a light guide plate in a backlight structure according to a second embodiment of the present disclosure;

FIG. 11 is a schematic cross-sectional view of a microstructure of a dot with a cambered surface structure according to a second embodiment of the present invention;

FIG. 12 is a schematic cross-sectional view of a backlight structure according to a third embodiment of the invention;

FIG. 13 is a schematic cross-sectional view of a backlight structure according to a fourth embodiment of the invention;

FIG. 14 is a schematic cross-sectional view of a backlight structure according to a fifth embodiment of the invention;

FIG. 15 is a schematic view of a light-emitting angle of a backlight structure according to a fifth embodiment of the invention;

FIG. 16 is a graph comparing the vertical field of view angle of the first embodiment of the present invention with a conventional backlight configuration;

FIG. 17 is a diagram comparing the horizontal field angle of the first embodiment of the present invention with a conventional backlight configuration;

FIG. 18 is a schematic diagram of different viewing direction angle settings according to different required scenarios.

Detailed Description

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. The illustrated exemplary embodiments of the invention are provided for purposes of illustration only and are not intended to be limiting of the invention. Therefore, it is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.

The backlight structure according to the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The first embodiment:

fig. 1 is a schematic cross-sectional structure diagram of a light guide plate and a backlight structure according to a first embodiment of the invention, and as shown in fig. 1, the backlight structure of this embodiment includes: the light guide plate 20 of the present embodiment has a light incident surface 21, a light emitting surface 22, and a reflecting surface 23, the light incident surface 21 is perpendicular to and adjacent to the light emitting surface 22, the light incident surface 21 is located at a side close to the light source 10, and the reflecting surface 23 is opposite to the light emitting surface 22, in this embodiment, the reflecting surface 23 has a plurality of convex or concave dot microstructures 24 thereon. In the present embodiment, taking a concave (concave into the main body of the light guide plate 20) dot microstructure as an example, in the present embodiment, as shown in fig. 1, the dot microstructure 24 is a concave pyramid structure. The light ray correction film 30 is located on one side of the light emitting surface 22 of the light guide plate 20, one side of the light ray correction film 30, which is far away from the light guide plate 20, is provided with a plurality of micro-prism structures 32 which extend in a direction parallel to the light incident surface 21 and are arranged discontinuously, the sections of the micro-prism structures 32 in a direction perpendicular to the light incident surface are triangular or the sections of the apex angles are arc-shaped triangular, the sections of the micro-prism structures 32 in a direction parallel to the light incident surface are trapezoidal, the length of the upper bottom of the trapezoid is the length of the tops of the micro-prism structures 32 which are arranged discontinuously, the length of the lower bottom of the trapezoid is the length of the bottoms of the micro-prism structures 32 which are arranged discontinuously, and gaps among the trapezoids are discontinuous parts of the micro-prism structures 32. The backlight structure of the present embodiment further includes a reflective sheet 50, wherein the reflective sheet 50 is located on one side of the reflective surface of the light guide plate 20, and is used for reflecting the light incident on the reflective sheet 50 from the light guide plate 20, and reusing the light to improve the light utilization rate of the backlight module.

Fig. 2 is a schematic view of a dot microstructure having a pyramid structure on a reflective surface of a light guide plate in a backlight structure according to a first embodiment of the invention, but the invention is not limited thereto. As shown in fig. 2, in the present embodiment, the dot microstructures 24 having a pyramid structure are concave dots recessed into the body of the light guide plate 20. Fig. 3 is a schematic diagram illustrating a possible cross-sectional structure of a dot microstructure of a pyramid structure according to a first embodiment of the present invention, as shown in fig. 3, in this embodiment, a cross section of the dot microstructure 24 is a triangle, but not limited thereto, if the dot microstructure 24 adopts a pyramid-like structure, for example, if a vertex of the pyramid is an arc surface, the cross section of the dot microstructure 24 is a triangle with an arc-shaped chamfer. In this embodiment, the dot microstructure 24 may also be a prismoid structure, where the cross section of the dot microstructure 24 is trapezoidal, and the dot microstructure 24 may also be a structure in which a plurality of prismoids are stacked, where the cross section of the dot microstructure is in the shape of a polygon with a step-change angle, and the like. In the present invention, the pyramid structure or the frustum structure defined by the dot microstructure 24 includes a suitable deformation of the pyramid structure or the frustum structure, for example, the edge of the pyramid or the frustum may also be in an arc shape, and the like, which is not described in detail. In the present invention, a contact angle between a tangent line of any point on the surface of the dot microstructure and the reflection surface is not greater than 7 °, in the present invention, for a structure in which the cross section of the dot microstructure 24 is a pyramid or a frustum of a pyramid, a contact angle between a tangent line of any point on the surface of the dot microstructure and the reflection surface at this time refers to an acute included angle between a prism surface of the pyramid or the frustum of a pyramid and the reflection surface, and for this embodiment, specifically, as long as an included angle α between each prism surface of the pyramid or the frustum of a pyramid structure and the reflection surface 23 is not greater than 7 °, if the included angle is formed by stacking a plurality of frustums, an included angle between each prism surface and the reflection surface is not greater than 7 °, so that the light-emitting angle of the light guide plate 20 having the dot microstructure 24 in the present invention is 60 ° to 90 °. In the invention, the dot microstructures 24 are arranged from sparse to dense along the direction far away from the light source 10, so that the emergent light from the side close to the light source 10 to the side far away from the light source 10 in the whole backlight source structure is more uniform on the whole light emergent surface.

Fig. 4 is a schematic cross-sectional view of a light-correcting film along a direction perpendicular to a light incident surface according to a first embodiment of the present invention, fig. 5 is a schematic cross-sectional view of the light-correcting film along a direction parallel to the light incident surface according to the first embodiment of the present invention, and referring to fig. 4 and fig. 5, in this embodiment, a light-correcting film 30 includes, for example, a substrate 31 and a micro-prism structure 32 formed on the substrate 31, and the substrate 31 and the micro-prism structure 32 may be made of the same material or different materials. Preferably, the refractive index of the microprism structure 32 is between 1.55 and 1.70. Fig. 6 is a schematic cross-sectional view of a microprism structure according to a first embodiment of the present invention taken along a direction perpendicular to an incident surface, and fig. 7 is a schematic cross-sectional view of another microprism structure according to a first embodiment of the present invention taken along a direction perpendicular to the incident surface, in which the cross-section of the microprism structure taken along the direction perpendicular to the incident surface is triangular, as shown in fig. 6. Preferably, the cross-section is an isosceles triangle, the base angle β of which (i.e., the angle between the laterally inclined surface 321 and the base of the triangle in FIG. 6) is in the range of 65-77. As shown in fig. 7, the cross section of the microprism structure along the direction perpendicular to the light incident surface may also be a triangle with an arc-shaped chamfer at the top angle, and preferably, the radius of curvature of the arc-shaped chamfer is less than 5 μm. In fig. 7, the base angle β of the triangle with the arc-shaped chamfer at the apex angle (i.e., the angle between the lateral inclined surface 321 and the bottom surface of the triangle with the arc-shaped chamfer at the apex angle in fig. 7) is in the range of 65 to 77 °, and the length of the base of the triangle or the triangle with the arc-shaped chamfer at the apex angle is in the range of 18 to 40 μm.

In this embodiment, the plurality of microprism structures 32 are arranged adjacently and repeatedly in parallel along the direction perpendicular to the light incident surface 21, and perform horizontal correction on all the light entering the light correction film from the light guide plate 20, so that the horizontal light exiting angle is corrected to be within ± 15 ° of the range perpendicular to the light exiting surface, and at the same time, perform vertical correction on the light entering the light correction film, so that the vertical light exiting angle is corrected to be within ± 20 ° of the range perpendicular to the light exiting surface, and the liquid crystal display device adopting the backlight structure of this embodiment has a better peep-proof effect.

FIG. 8 is a schematic cross-sectional view of a microprism structure along a direction parallel to the light incident surface in accordance with a first embodiment of the present invention; as shown in fig. 8, in the present embodiment, the micro-prism structures 32 extend along the direction parallel to the light incident surface 21 and are arranged intermittently, the cross section of the micro-prism structures 32 along the direction parallel to the light incident surface is a trapezoid, preferably, the trapezoid is an isosceles trapezoid, the base angle γ (i.e., the included angle between the longitudinal inclined surface 322 and the lower base of the trapezoid) of the trapezoid is within the range of 65 ° -77 °, and the length of the base side of the trapezoid is between 100 microns and 500 microns. In this embodiment, the length of the upper and lower trapezoidal bases and the bottom angle γ of the trapezoid can be adjusted according to the requirements of different longitudinal light-emitting angles, that is, the micro-prism structures 32 arranged intermittently can be set as required to set the distance between the interruptions and adjust the included angle between the longitudinal inclined plane 322 and the lower trapezoidal base, so as to adjust the longitudinal light-emitting angle. In this embodiment, the lengths of the plurality of prism segments spaced from each other may be the same, or the lengths may be randomly distributed within the range of 100-500 μm, the base angles γ and β of the trapezoid may be the same or different,

in the present invention, the light ray correction film 30 is disposed on the side away from the light guide plate 20, and the light ray correction film 30 has a plurality of micro-prism structures 32 that extend in the direction parallel to the light incident surface 21 and are arranged intermittently, so as to achieve the adjustment of the transverse and longitudinal light emergent angles at the same time.

In this embodiment, the light source 10 is preferably an LED light bar, but is not limited thereto, and other light sources may be adopted. The dot microstructures 24 may also be convex dots protruding outward from the light guide plate 20, and will not be described in detail.

Second embodiment:

the same parts of this embodiment as those of the first embodiment are not described again, but the difference is that in this embodiment, the dot microstructure 24 is a concave arc structure.

Fig. 9 is a schematic cross-sectional structure view of a backlight structure according to a second embodiment of the present invention, and as shown in fig. 9, in this embodiment, the dot microstructures 24 are of a concave arc-shaped structure (recessed into the main body of the light guide plate 20). Fig. 10 is a schematic view of a dot microstructure with an arc-shaped structure on a reflective surface of a light guide plate in a backlight structure according to a second embodiment of the present invention, in this embodiment, the dot microstructures 24 are also distributed from sparse to dense along a direction away from the light source 10, so that emergent light from a side close to the light source 10 to a side away from the light source 10 in the entire backlight structure is more uniform on the entire light-emitting surface.

Fig. 11 is a schematic cross-sectional view illustrating a cross-sectional structure of a dot microstructure of an arc-shaped structure according to a second embodiment of the present invention, as shown in fig. 11, in the present invention, a contact angle between a tangent line of any point on a surface of the dot microstructure and a reflective surface is not greater than 7 °, in this embodiment, the contact angle refers to an included angle between the tangent line of any point on the arc-shaped structure and the reflective surface, and an included angle θ between the tangent line of any point on the arc-shaped structure and the reflective surface in this embodiment is not greater than 7 °, so that a light-emitting angle of the light guide plate 20 having the dot microstructure 24 according to the present invention is between 60 ° and 90 °, and after the light is emitted, the light-emitting angle is corrected to be within ± 15 ° perpendicular to the light-emitting surface after passing through the light-correcting film 30.

In the invention, the cambered surface structure can be one of a partial spherical surface, an ellipsoid or an elliptic paraboloid, the projection of the cambered surface structure on the reflecting surface is a circle or an ellipse, and the diameter of the circle or the major axis of the ellipse is not more than 130 microns. In this embodiment, as shown in fig. 11, the arc-shaped structure is a partial spherical structure, an included angle θ between a tangent of any point on the arc-shaped structure and the reflection surface is not greater than 7 °, a projection of the arc-shaped structure on the reflection surface is circular, and a diameter R of the circular is not greater than 130 μm.

In this embodiment, as shown in fig. 11, the coordinates of any point on the arc structure need to satisfy the following equation:

Ax²+By²=z

wherein z is more than or equal to 0 and less than or equal to 6.5; a is more than or equal to 0 and less than or equal to 6.2 multiplied by 10^-3；0≤B≤6.2×10^-3；

In this embodiment, the structure of the light-correcting film 30 is the same as that of the first embodiment, and is not described again.

The third embodiment:

in this embodiment, the light-emitting surface 22 and the reflective surface 23 are distributed with dot microstructures 24 having a pyramid structure, and the dot microstructures 24 are also concave (recessed into the main body of the light guide plate 20).

Fig. 12 is a schematic cross-sectional view of a backlight structure according to a third embodiment of the present invention, as shown in fig. 12, in this embodiment, a light ray a is an emergent light path diagram of light emitted from a light source 10 under the action of a dot microstructure 24 on a reflective surface of a light guide plate 20, and a light ray B is an emergent light path diagram of light emitted from the light source 10 under the action of the dot microstructure 24 on a light exit surface of the light guide plate 20.

In this embodiment, the dot microstructures 24 may also be convex dots protruding outward from the light guide plate 20, and are not described again.

The fourth embodiment:

in this embodiment, the light-emitting surface 22 and the reflective surface 23 are distributed with dot microstructures 24 having an arc-shaped structure, and the dot microstructures 24 are also concave (concave into the light guide plate 20 body).

Fig. 13 is a schematic cross-sectional view illustrating a backlight structure according to a fourth embodiment of the present invention, as shown in fig. 13, in this embodiment, after light exits from the light exit surface 22 of the light guide plate 20, the light exit angle is between 60 ° to 90 °, and after the light exits through the light correction film 30, the light exit angle is corrected to be perpendicular to the light exit surface within ± 15 ° to exit.

In this embodiment, the dot microstructures 24 may also be convex dots protruding outward from the light guide plate 20, and are not described again.

Fifth embodiment:

the same parts of this embodiment as those of the first embodiment are not repeated, but the difference is that in this embodiment, a diffusion sheet 40 is further included on the side of the light-straightening film 30 away from the light guide plate 20.

Fig. 14 is a schematic cross-sectional view illustrating a backlight structure according to a fifth embodiment of the present invention, and as shown in fig. 14, in the backlight structure of this embodiment, a diffusion sheet 40 is further disposed outside the light-correcting film 30 to further adjust the light emitted from the backlight structure.

Fig. 15 is a schematic view of the light-emitting angle of the backlight structure according to the fifth embodiment of the present invention, as shown in fig. 15, in this embodiment, since the light-emitting angle of the emitted light is corrected to be within ± 15 ° of being perpendicular to the light-emitting surface after passing through the light-correcting film 30, the light-emitting angle is relatively concentrated within the angle range, the diffusion sheet 40 is a film having a certain light-diffusing effect, and the light emitted from the light-correcting film 30 can be adjusted twice through the diffusion sheet 40, so as to improve the brightness uniformity and adjust the light-emitting direction, so as to meet the application of display devices with different viewing angle requirements. Because the traditional backlight source structure has a large angle range of light beams behind the diffusion sheet, the degree of light ray adjustment is limited, and the difficulty is large, and the backlight source structure can further flexibly and simply regulate and control the emergent light angle according to the requirement.

In the present invention, the diffusion sheet 40 can also be applied to the structures of the second to fourth embodiments to achieve substantially the same technical effects, and the details are not repeated.

In the invention, the dot microstructures with specific structures and angle distribution are arranged on the reflecting surface of the light guide plate, and the light correction film with specific structures is arranged, so that light with a certain angle emitted from the light guide plate enters the light correction film and then the emitted light is corrected to the required direction. Fig. 16 is a comparison graph of the vertical field angle of the first embodiment of the present invention and the conventional backlight structure, fig. 17 is a comparison graph of the horizontal field angle of the first embodiment of the present invention and the conventional backlight structure, and as can be seen from fig. 16 and fig. 17, the backlight structure of the present invention greatly increases the forward light intensity (approximately twice the forward light intensity of the conventional backlight structure) in both the vertical field and the horizontal field, the vertical field of the backlight structure of the present invention is mainly concentrated within ± 15 °, the horizontal field of the backlight structure is mainly concentrated within ± 20 °, and a liquid crystal display device using the backlight structure of the present invention has a better peep-proof effect.

Fig. 18 is a schematic view of the present invention for realizing angle settings in different visual directions according to different scenes with different requirements, and the backlight structure of the present invention can set the visual effect of the maximum light intensity emission in different visual directions as required, and as shown in fig. 18, the maximum light intensity emission angle distributions at several angles are exemplarily set: the included angles in the vertical direction with the light emitting surface are respectively 0 °, 18 °, 26 ° and 48 °, and fig. 16 is only an example of several angles, and the present invention is not limited to these angles, and the base angles of the micro-prism structure in the present invention can be set correspondingly according to the needs of different angles or different use scenes, and are not described again.

The mesh point microstructure on the reflecting surface of the light guide plate can be formed by adopting a bump point or a precision machining process, and the mesh point microstructure can be a concave mesh point structure or a convex mesh point structure. The backlight source structure can effectively improve the light utilization rate and increase the display brightness in the front viewing direction, reduces the use of optical films and the thickness and the cost of a backlight module compared with the traditional backlight source structure, and can be applied to the fields of electronic products such as low-power-consumption, light and thin mobile phones, pads, notebook computers and the like or other display products with specific visual direction requirements.

The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.