CN209784579U - Light guide plate and backlight module - Google Patents

Abstract

The embodiment of the utility model discloses a light guide plate and a backlight module. The light guide plate includes a light incident surface, a light exit surface and a bottom surface, the light exit surface and the bottom surface are arranged opposite to each other, the light incident surface is connected to the light exit surface and the bottom surface, the light incident surface includes a plurality of arc-like surfaces, and the adjacent arc-like surfaces are planes; The arc-like surface is concave toward the body of the light guide plate; each arc-like surface includes two curved surfaces and a plane between the two light curved surfaces. The technical scheme provided by the utility model can reduce dark areas between lamps and dark areas in corners.

Description

A light guide plate and a backlight module

technical field

The embodiment of the utility model relates to the field of display technology, in particular to a light guide plate and a backlight module.

Background technique

The liquid crystal display panel itself is not luminous. Therefore, it is necessary to provide a side light source device for the liquid crystal display panel, such as a backlight module. The backlight module can be divided into side-type, direct-type and hollow-type according to the position of the light source.

Among them, the traditional side-type backlight module usually uses Light Emitting Diode (LED) as the backlight source, because the LED emits a lot of heat when it is working, and the light-incident side space of the backlight module is small, which is not conducive to heat dissipation. Therefore, it is easy to accumulate heat and cause the ambient temperature in the backlight module to be relatively high, thereby causing problems such as dead lights and warping of the light guide plate film. In order to ensure the safety of the backlight module, in the prior art, the design quantity of LEDs is usually reduced to reduce heat generation, but this will cause problems of dark areas between lamps and dark areas in corners.

Utility model content

The utility model provides a light guide plate and a backlight module to reduce dark areas between lamps and corners.

In a first aspect, an embodiment of the present invention provides a light guide plate, which includes:

The light incident surface, the light exit surface and the bottom surface, the light exit surface and the bottom surface are arranged opposite to each other, and the light incident surface is connected with the light exit surface and the bottom surface;

The light incident surface includes multiple arc-like surfaces, and the adjacent arc-like surfaces are planes; the arc-like surfaces are concave toward the body of the light guide plate; each arc-like surface includes two curved surfaces and a plane between the two light curved surfaces.

Optionally, the vertical distance between the planes between adjacent arc-like surfaces and the plane of the arc-like surfaces is 0.5-0.8 mm.

Optionally, a light converging unit is further arranged on the plane of the arc-like surface.

Optionally, the light converging unit is a columnar convex structure, and the convex direction of the columnar convex structure is opposite to the concave direction of the arc-like surface.

Optionally, the ratio of the area of the arc-like plane to the area of the arc-like surface is less than one-third, and the area of the vertical projection of the light converging unit on the arc-like plane is less than or equal to the area of the arc-like plane .

Optionally, the curved surface is also provided with a light diverging unit.

Optionally, the light diverging unit includes a plurality of convex structures and/or concave structures relative to the curved surface.

Optionally, the light diverging unit includes a prism structure.

In the second aspect, the embodiment of the present utility model also provides a backlight module, which includes:

A plurality of backlight sources and the light guide plate described in any embodiment;

The backlight source is located on the side of the light incident surface of the light guide plate; multiple backlight sources are arranged in multiple arc-like surfaces correspondingly, and the center of the backlight source is directly opposite to the plane of the arc-like surface.

Optionally, the backlight source and the light guide plate satisfy the following formula:

sina*n ₁ = sinb*n ₂ ;

D*tana＝(L/2)-(H/cotb)

Wherein, H is the vertical distance between the light-emitting surface of the backlight and the plane between the adjacent arc-like surfaces; D is the vertical distance between the shielding edge of the middle frame of the display panel and the plane between the adjacent arc-like surfaces; L is the distance between two adjacent backlight sources; n ₁ is the refractive index of air; n ₂ is the refractive index of the light guide plate; the vertical line between the edge of the backlight source closest to the boundary and the boundary is S1, a is S1 and the input The angle between the normal lines of the light surface; b is the refraction angle of the incident light in the light guide plate when the angle between the incident light and the normal line of the light incident surface is a.

The utility model arranges a plurality of arc-like surfaces on the light-incident surface of the light guide plate, so that when the backlight source and the arc-like surfaces face each other, the two curved surfaces in each arc-like surface diverge and are set correspondingly. The light emitted by the two edges of the backlight source, thereby increasing the refraction angle of the light emitted by the edge of the backlight source in the light guide plate, solves the dark area of the lamp shadow due to the large distance between adjacent backlight sources in the prior art and The problem of the dark area in the corner can achieve the effect of reducing the dark area of the light shadow and the dark area of the corner.

Description of drawings

Fig. 1 is a schematic diagram of a backlight module provided by the prior art;

Fig. 2 is a schematic top view of a light guide plate provided by the utility model;

FIG. 3 is a schematic perspective view of the light guide plate provided in FIG. 2;

Fig. 4 is the working principle diagram of the arc-like surface provided by the utility model;

Fig. 5 is a schematic top view of another light guide plate provided by the present invention;

Fig. 6 is a schematic perspective view of the light guide plate provided in Fig. 5

Fig. 7 is a schematic top view of another light guide plate provided by the present invention;

FIG. 8 is a schematic perspective view of the light guide plate provided in FIG. 7;

Fig. 9 is a three-dimensional schematic diagram of another light guide plate provided by the present invention;

Fig. 10 is a schematic diagram of a backlight module provided by an embodiment of the present invention;

Fig. 11 is a schematic diagram of a kind of arc surface positioning provided by the utility model.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail. It can be understood that the specific embodiments described here are only used to explain the utility model, rather than limit the utility model. In addition, it should be noted that, for the convenience of description, only some structures related to the present utility model are shown in the drawings but not all structures.

FIG. 1 is a schematic diagram of a backlight module provided in the prior art. Referring to Fig. 1, the backlight module includes a backlight source 11 and a light guide plate 12, the backlight source 11 is arranged facing the light incident surface of the light guide plate 12, and the light emitted by the backlight source 11 is refracted after entering the light guide plate 12, however, due to the backlight The outgoing light of 11 has a certain outgoing angle, so that the dark area 122 between lamps and the dark area 121 at the corner appears on the light guide plate 12, and the dark area 122 between the lamps and the dark area 121 at the corner both exceed the shielding edge line of the middle frame of the display panel 13, multiple dark areas will appear in the display area of the display panel.

In view of this, the embodiment of the present invention provides a light guide plate. FIG. 2 is a schematic top view of the light guide plate provided by the present invention, and FIG. 3 is a perspective view of the light guide plate provided in FIG. 2 . Referring to Fig. 2 and Fig. 3, the light guide plate includes a light incident surface, a light exit surface and a bottom surface, the light exit surface is opposite to the bottom surface, the light incident surface is connected to the light exit surface and the bottom surface, and the light incident surface includes a plurality of arc-like surfaces 22 adjacent to each other. Between the arc-like surfaces 22 is a plane 21 , and the arc-like surfaces 22 are recessed toward the body of the light guide plate; each arc-like surface 22 includes two curved surfaces 221 and a plane 222 between the two curved light surfaces 221 .

Wherein, the light incident surface is used to receive the light emitted by the backlight source, the light exit surface and the bottom surface are connected to the light incident surface, and the light exit surface and the bottom surface are opposite to each other. Figure 2 and Figure 3 exemplarily show that the light guide plate has a light incident surface, The light emitting surface is perpendicular to the light incident surface, but it is not a limitation to the structure of the light guide plate of the present application. In other technical solutions, the light guide plate can also be provided with multiple light incident surfaces, for example, the light guide plate has two light incident surfaces, and the two light incident surfaces Glossy relative setting.

Fig. 4 is a working principle diagram of the arc-like surface provided by the utility model. Referring to Fig. 4, the backlight source corresponds to the arc-like surface one by one, and the center of the backlight source is directly opposite to the center of the arc-like surface. The refracted light when the light emitted from the edge of the backlight is incident on a plane, and the solid line represents the refracted light when the light emitted by the edge of the backlight is incident on a curved surface. Specifically, when the light emitted from the edge of the backlight is incident on the arc-like curved surface 221, the incident angle increases compared to the light incident on the flat light guide plate in the prior art. According to the law of refraction, the exit angle also increases correspondingly. , so that the dark areas between the lamps and the dark areas of the corners are reduced, and when the dark areas between the lamps and the dark areas of the corners are reduced to within the shielding edge line 13 of the middle frame of the display panel, no dark areas will appear in the display area of the display panel. In addition, the arc-like plane 221 does not diverge the light emitted by the backlight, so that the light guide plate receives light with relatively concentrated energy, thereby ensuring the brightness of the light guide plate.

The utility model arranges a plurality of arc-like surfaces on the light-incident surface of the light guide plate, so that when the backlight source and the arc-like surfaces face each other, the two curved surfaces in each arc-like surface diverge and are set correspondingly. The light emitted from the two edges of the backlight source reduces the dark area of the light shadow and the dark area of the corner to the edge line of the middle frame of the display panel, and the plane of the arc-like surface ensures that the light guide plate receives light with relatively concentrated energy, which solves the problem The problem of light shadow dark area and corner dark area can reduce the light shadow dark area and corner dark area while ensuring the effect of luminous brightness.

On the basis of the above technical solution, optionally, a light converging unit is further arranged on the arc-like plane. There are many specific arrangements of the light concentrating unit, and typical examples are described below, but this application is not limited thereto.

FIG. 5 is a schematic top view of another light guide plate provided by the present invention, and FIG. 6 is a schematic perspective view of the light guide plate provided in FIG. 5 . Referring to FIG. 5 and FIG. 6 , the light converging unit is a columnar convex structure 223 , and the convex direction of the columnar convex structure 223 is opposite to the concave direction of the arc-like surface. Wherein, the columnar convex structure 223 extends from the light exit surface of the light guide plate to the bottom surface of the light guide plate. Fig. 5 exemplarily shows that the projection of the columnar convex structure 223 on the light exit surface of the light guide plate is an arc. In other technical solutions , can also be U-shaped. It should be noted that, FIG. 5 only exemplarily shows that a columnar convex structure is provided on the arc-like plane 222, and the area of the vertical projection of the columnar convex structure on the arc-like plane 222 is the same as that of the arc-like plane. The area of 222 is the same, but it is not a limitation to the present application. The number of columnar convex structures 223 arranged on the arc-like plane 222 and the area of the vertical projection of the columnar convex structures 223 on the arc-like plane 222 are known in the art Technicians can set it according to the actual situation.

The advantage of such arrangement is that the columnar convex structure 223 can converge the light incident on it, so as to further improve the luminous brightness of the light guide plate.

Optionally, the ratio of the area of the arc-like plane to the area of the arc-like surface is less than one-third, and the area of the vertical projection of the light converging unit on the arc-like plane is less than or equal to the area of the arc-like plane . This setting can prevent the light converging unit from being too large, causing most of the light emitted by the backlight to reach the converging unit and be converged, while a small part of the light reaches the arc-like curved surface and is diverged, which will affect the light uniformity of the light guide plate.

On the basis of the above technical solution, optionally, a light diverging unit is further arranged on the arc-like curved surface. There are many specific configurations of the light diverging unit, typical examples will be described below, but this application is not limited.

FIG. 7 is a schematic top view of another light guide plate provided by the present invention, and FIG. 8 is a schematic perspective view of the light guide plate provided in FIG. 7 . Referring to FIG. 3 and FIG. 4 , the light diverging unit includes a prism structure 224 . Specifically, at least one prism structure 224 is provided on the curved surface of the arc-like surface. The prism structure 224 can be convex or concave relative to the curved surface of the arc-like surface. The prism structure 224 extends from the light-emitting surface of the light guide plate to the The vertical projection of the bottom surface of the light guide plate on the light emitting surface of the light guide plate may be triangular, trapezoidal or fan-shaped. The prism structure 224 can also extend from the boundary between the arc-like curved surface and the plane of the light guide plate along the light-emitting surface parallel to the light guide plate to the junction of the arc-like curved surface and the arc-like plane, and extend perpendicular to it. The shape of the cross-section of the direction can be triangular, trapezoidal or fan-shaped, etc. It should be noted that the shape, size and quantity of the prism structure 224 can be set by those skilled in the art according to the actual situation, which is not limited in the present application.

The advantage of this setting is that the prism structure 224 can diverge the light incident on it, and enhance the divergence ability of the light emitted from the edge of the arc-like surface of the backlight, thereby further reducing the area of the dark area of the lamp shadow and the dark area of the corner.

FIG. 9 is a schematic perspective view of another light guide plate provided by the present invention. Referring to FIG. 9 , the light diverging unit includes a plurality of convex structures (not shown in FIG. 9 ) and/or concave structures 225 relative to the curved surface. Specifically, at least one convex structure and/or concave structure 225 is set on the curved surface of the arc-like surface, and the projection of the prism structure on the curved surface of the arc-like surface can be a regular figure such as a circle or a triangle, or an irregular figure . It can be understood that when the concave structure 225 is provided on the arc-like curved surface, it is only necessary to imprint the mold with the same shape as the concave structure 225 on the arc-like curved surface, and the process is relatively simple.

Optionally, the diameter of the protrusion structure is less than 0.05 mm, the diameter of the depression structure 225 is less than 0.05 mm, and the distance between adjacent protrusion structures and/or the distance between protrusion structures is less than 0.1 mm.

The advantage of such setting is that the raised structure and/or the raised structure can enhance the divergence of light emitted from the edge of the backlight by the arc-like surface, thereby further reducing the area of the dark area of the lamp shadow and the dark area of the corner.

On the basis of the above technical solution, optionally, the vertical distance between the planes between adjacent arc-like surfaces and the plane of the arc-like surfaces is 0.5-0.8 mm.

Among them, the larger the vertical distance between the planes between the adjacent arc-like surfaces and the plane of the arc-like surfaces, the larger the refraction angle of the curved-like surfaces to the incident light, which is more conducive to improving the dark areas of lamp shadows and dark corners. However, the larger the vertical distance between the light surface of the light guide plate and the backlight source, the greater the light energy loss of the backlight source, and the smaller the light output brightness of the light guide plate, and the light output brightness of the light guide plate is a measure of the light guide plate. An important parameter of performance. In addition, when the vertical distance between the planes between the adjacent arc-like surfaces and the arc-like planes is too large, causing the arc-like planes to approach the middle frame of the display panel, the display panel This kind of curved surface depression may be seen in the display area of the display area, which will affect the display effect of the display panel. Therefore, it is necessary to reasonably set the vertical distance between the planes between adjacent arc-like surfaces and the planes of similar arc-like surfaces. Ensure the light energy utilization rate of the backlight source.

Fig. 10 is a schematic diagram of a backlight module provided by an embodiment of the present invention. The backlight module includes: a plurality of backlight sources 11 and the light guide plate described in any embodiment of the present invention. The backlight source 11 is located on the light guide plate One side of the light incident surface; a plurality of backlight sources 11 are arranged in a plurality of arc-like surfaces in one-to-one correspondence, and the center of the backlight source 11 is directly opposite to the plane of the arc-like surface.

The backlight module includes any light guide plate described above, so the backlight module has corresponding functions and beneficial effects.

It can be understood that, compared with the prior art, the backlight module not only reduces the number of backlight sources, thereby improving heat dissipation and reducing costs, but also prevents dark areas of light shadows and corners from appearing outside the edge of the middle frame, ensuring Light quality. In addition, the quasi-curved surface can be realized by finishing cutting and polishing, or by mold injection molding. The technology is mature and the processing is simple.

Continue to refer to Figure 10, on the basis of the above technical solution, optionally, a light converging unit is also provided on the plane of the arc-like surface; the connection line between the edge of the light converging unit and the center of the backlight is perpendicular to the The angle C between the directions of the planes is less than 45°. Such setting can ensure that the size of the light converging unit will not be too large, thereby affecting the arc-like curved surface and enlarging the light energy distribution angle of the backlight source.

Fig. 11 is a schematic diagram of a kind of arc surface positioning provided by the utility model. The backlight source and the light guide plate satisfy the following formula:

sina*n ₁ = sinb*n ₂ ;

D*tana＝(L/2)-(H/cotb)

Wherein, H is the vertical distance between the light-emitting surface of the backlight and the plane between the adjacent arc-like surfaces; D is the vertical distance between the shielding edge of the middle frame of the display panel and the plane between the adjacent arc-like surfaces; L is the distance between two adjacent backlight sources; n ₁ is the refractive index of air; n ₂ is the refractive index of the light guide plate; the vertical line between the edge of the backlight source closest to the boundary and the boundary is S1, a is S1 and the input The angle between the normal lines of the light surface; b is the refraction angle of the incident light in the light guide plate when the angle between the incident light and the normal line of the light incident surface is a.

Specifically, continue to refer to Figure 10, the two curved surfaces of the quasi-arc surface intersect the light-emitting surface of the light guide plate, and the intersection line is two sections of curves. The two sections of curved surfaces are two sections of arcs on the same circumference, and the arc lengths are the same. The missing arc segments between the two arcs can be completed, and can be connected into an arc 226 . H, D, L, n ₁ , and n ₂ are known quantities. According to the above two formulas, the values of a and b can be calculated, and then the two boundary points A and B of the arc 226 can be calculated, that is, the circle can be determined. Two points on the arc 226, the vertical distance between the plane between the adjacent arc-like surfaces and the plane between the arc-like surfaces can be approximately regarded as the vertical distance from the midpoint of the arc 226 to the plane between the adjacent arc-like surfaces , that is to determine the midpoint on the arc 226, thereby determine the design parameters of the arc 226 through the three points, and then determine the arc-like surface by the ratio of the area of the plane of the arc-like surface to the area of the arc-like surface Design Parameters.

Note that the above are only preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the utility model is not limited to the specific embodiments described here, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the utility model. Therefore, although the utility model has been described in detail through the above embodiments, the utility model is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the utility model. The scope of the present invention is determined by the appended claims.

Claims (10)

1. A light guide plate, characterized in that, comprising: A light incident surface, a light exit surface, and a bottom surface, the light exit surface is arranged opposite to the bottom surface, and the light incident surface is connected to the light exit surface and the bottom surface; The light incident surface includes a plurality of arc-like surfaces, and the adjacent arc-like surfaces are planes; the arc-like surfaces are recessed toward the body of the light guide plate; each of the arc-like surfaces includes two curved surfaces and A plane that lies between two light surfaces. 2 . The light guide plate according to claim 1 , wherein the vertical distance between the planes between the adjacent arc-like surfaces and the plane of the arc-like surfaces is 0.5-0.8 mm. 3 . The light guide plate according to claim 1 , wherein a light converging unit is further arranged on the plane of the arc-like surface. 4 . 4. The light guide plate according to claim 3, wherein the light converging unit is a columnar convex structure, and the convex direction of the columnar convex structure is opposite to the concave direction of the arc-like surface. 5. The light guide plate according to claim 3, wherein the ratio of the area of the arc-like surface to the area of the arc-like surface is less than one-third, and the light converging unit is The area of the vertical projection on the plane of the arc surface is less than or equal to the area of the plane of the quasi-arc surface. 6. The light guide plate according to claim 1, wherein the curved surface is further provided with a light diverging unit. 7. The light guide plate according to claim 6, wherein the light diverging unit comprises a plurality of convex structures and/or concave structures relative to the curved surface. 8. The light guide plate according to claim 6, wherein the light diverging unit comprises a prism structure. 9. A backlight module, characterized in that it comprises: A plurality of backlight sources and the light guide plate according to any one of claims 1-8; The backlight source is located on one side of the light incident surface of the light guide plate; a plurality of the backlight sources are arranged in a plurality of the arc-like surfaces in one-to-one correspondence, and the center of the backlight source and the center of the arc-like surface The plane is facing. 10. The backlight module according to claim 9, characterized in that, The backlight source and the light guide plate satisfy the following formula: sina*n ₁ = sinb*n ₂ ; D*tana＝(L/2)-(H/cotb) Wherein, H is the vertical distance between the light-emitting surface of the backlight and the plane between the adjacent arc-like surfaces; D is the distance between the middle frame shielding edge of the display panel and the adjacent arc-like surfaces The vertical distance between the planes between; L is the distance between two adjacent backlight sources; n ₁ is the refractive index of air; n ₂ is the refractive index of the light guide plate; the edge of the backlight source closest to the boundary The vertical connection line with the boundary is S1, and a is the angle between S1 and the normal line of the light incident surface; when b is the angle between the incident light and the normal line of the light incident surface, the The refraction angle of the incident light in the light guide plate.