[0014] See figure 1 and figure 2 The backlight module 100 provided by the first embodiment of the present invention includes a light guide plate 10, a plurality of light sources 20, and a reflective sheet 30.
[0015] The light guide plate 10 is arranged above the light sources 20, that is, the light guide plate 10 is opposite to the light sources 20. The light guide plate 10 is roughly plate-shaped, and has a light incident surface 11 and a light output surface 12 opposite to each other. The light incident surface 11 and the light exit surface 12 are arranged parallel to each other. The light incident surface 11 is opposite to the light source 20.
[0016] The light guide plate 10 is made of light-transmissive material, and the material of the light guide plate 10 can be polycarbonate (PC), polymethyl methacrylate (PMMA), methyl methacrylate, styrene copolymer ( MS), polyethylene terephthalate (PETG), polystyrene (PS) or a mixture of two or more of the above materials.
[0017] The light-emitting surface 12 of the light guide plate 10 is formed with a microstructure 13. The microstructure 13 is a plurality of triangular prism-shaped protrusions 131 that are parallel to and separated from each other, and the length direction of the triangular prism-shaped protrusions 131 is parallel to the light emitting surface 12. The triangular prism-shaped protrusion 131 has a first side surface 1311 and a second side surface 1312 that are connected to each other. The first side surface 1311 and the second side surface 1312 are both connected to the light emitting surface 12, and the first side surface 1311 and the second side surface 1312 are connected to each other. The angle θ between the side surfaces 1312 is 130 degrees to 170 degrees, the intersection line of the first side surface 1311 and the second side surface 1312 is parallel to the light emitting surface 12, and the intersection line of the first side surface 1311 and the second side surface 1312 is parallel to The distance H of the light emitting surface 12 is 1.3 to 5.5 μm, and the distance P between the intersection of the first side surface 1311 and the second side surface 1312 of two adjacent triangular prism-shaped protrusions 131 is 30 μm to 50 μm.
[0018] In this embodiment, the spacing between the plurality of triangular prism-shaped protrusions 131 is equal. Preferably, the included angle θ between the first side surface 1311 and the second side surface 1312 is 130 degrees to 150 degrees, and the distance H between the intersection line of the first side surface 1311 and the second side surface 1312 and the light emitting surface 12 is 4 The distance P between the intersection of the first side surface 1311 and the second side surface 1312 of the two adjacent triangular prism-shaped protrusions 131 is 40 to 50 μm. More preferably, the included angle θ between the first side surface 1311 and the second side surface 1312 is 130 degrees, and the distance H between the intersection line of the first side surface 1311 and the second side surface 1312 and the light-emitting surface is 5.5 micrometers. The distance P between the intersection of the first side surface 1311 and the second side surface 1312 of two adjacent triangular prism-shaped protrusions 131 is 50 microns.
[0019] In other words, each triangular prism-shaped protrusion 131 is one of the three sides of the triangular prism and the light-emitting surface 12 overlaps with each other, and the other two sides of the triangular prism are the first side 1311 and the second side respectively. Side 1312. The longitudinal section of the triangular prism-shaped protrusion 131 is an isosceles triangle. The angle away from the light emitting surface 12 is the apex angle of the isosceles triangle. The angle θ of the apex angle is 130 degrees to 170 degrees. The distance H between the vertex of the isosceles triangle away from the light-emitting surface 12 and the light-emitting surface 12 is 1.3 to 5.5 microns, and the distance between the vertices of the longitudinal sections of two adjacent triangular prism-shaped protrusions 131 is P30 microns to 50 microns.
[0020] Preferably, the angle θ of the apex angle is 130 degrees to 150 degrees. The distance H between the apex of the isosceles triangle away from the light-emitting surface 12 and the light-emitting surface 12 is 4 μm to 5.5 μm, and the distance P between the vertices of the longitudinal sections of two adjacent triangular prism-shaped protrusions 131 It is 40 microns to 50 microns. More preferably, the angle θ of the apex angle is 130 degrees. The distance H between the vertex of the isosceles triangle away from the light-emitting surface 12 and the light-emitting surface 12 is 5.5 microns, and the distance P between the vertices of the longitudinal sections of two adjacent triangular prism-shaped protrusions 131 is 50 microns .
[0021] The multiple light sources 20 are located between the light guide plate 10 and the reflective sheet 30 and are used to emit light to the light guide plate 10.
[0022] The reflection sheet 30 is disposed under the plurality of light sources 20, that is, the reflection sheet 30 is opposite to the plurality of light sources 20. The reflective sheet 30 is used to reflect the light from the light source 20 to the light guide plate 10 to improve the light utilization rate of the light source 20.
[0023] See image 3 and Figure 4 , This technical solution also measures the light-emitting angle of backlight modules with different microstructure sizes. Wherein, in the first embodiment, the included angle between the first side surface 1311 and the second side surface 1312 is 170 degrees, and the distance between the intersection line of the first side surface 1311 and the second side surface 1312 and the light emitting surface 12 is 1.3 Micron, the distance between the intersection of the first side surface 1311 and the second side surface 1312 of two adjacent triangular prism-shaped protrusions 131 is 30 micrometers. In the second embodiment, the included angle between the first side surface 1311 and the second side surface 1312 is 130 degrees, and the distance between the intersection line of the first side surface 1311 and the second side surface 1312 and the light-emitting surface is 5.5 micrometers. The distance between the intersection of the first side surface 1311 and the second side surface 1312 of two adjacent triangular prism-shaped protrusions 131 is 50 microns. Using the same light source, the light output angle distribution measuring instrument is used to separately test the light output angle of the backlight module. The light output angle of the second embodiment is significantly more concentrated than that of the first embodiment.
[0024] The backlight module 100 of the present technical solution may further include a brightness enhancement film 40 which is arranged on the side of the light emitting surface 12 of the light guide plate 10 and is arranged in parallel with the light guide plate 10. The brightness enhancement film 40 can adjust the angle of the light emitted from the light guide plate 10 so that the emitted light is at a positive viewing angle.
[0025] In this technical solution, the brightness of the two backlight modules with the same light source 20 and the same brightness enhancement film 40 and the light guide plate provided in the first embodiment and the second embodiment is also tested. In this embodiment , Measure 100 different points of the backlight module at the front viewing angle, and the data obtained is as follows:
[0026] Test point The first embodiment brightness value (cd/m 2 ) The first embodiment brightness value (cd/m 2 ) 1 7363 8345 2 7341 8250 3 7456 8280 4 7504 8305 5 7439 8259 6 7268 8094 7 7085 7847 8 7036 7618 9 6761 7039 10 6328 6292 average 7167.1 7832.9
[0027] It can be seen from the above data that the light guide plate in the second embodiment has a more obvious effect of increasing the brightness value of the front viewing angle of the backlight module.
[0028] When the light emitted by the light source 20 in the technical solution passes through the light guide plate 10, the emitted light is adjusted by the microstructure of the light guide plate 10, so that the distribution angle of the light emitted by the backlight module 100 is more concentrated, and the brightness of the front view angle The value is higher, and cheaper light sources with lower brightness can be used, which can meet the brightness value requirements of the backlight module 100 in the front viewing angle.
[0029] It can be understood that those skilled in the art can also make other changes within the spirit of the present invention, which should be included in the scope of protection of the present invention.
