Backlight module

A backlight module, comprising:

• a reflective element, having a first surface, a second surface, and a plurality of light source grooves, wherein the first surface is opposite to the second surface, the light source grooves extend from the first surface to the second surface, and each of the light source grooves has a light-emitting outlet on the first surface;
• a plurality of light-emitting elements, respectively disposed in the light source grooves;
• and
• a light diffusion plate, disposed opposite to the first surface, wherein a distance between the light diffusion plate and the first surface is 0.5 mm to 4 mm;
• the backlight module further comprising a support element, wherein the support element is fixed to the reflective element and abuts against the light diffusion plate so that the distance is formed between the light diffusion plate and the first surface;
• wherein the first surface has an outer edge, the outer edge surrounds the light-emitting outlets, and the support element is fixed to the reflective element along the outer edge;
• wherein the support element comprises a plurality of segments along the outer edge and separated from each other, and a gap is formed between the two segments next to each other;
• wherein the light diffusion plate has a light emitting surface and a light incident surface, the light emitting surface faces away from the first surface and is opposite to the light incident surface, and the light emitting surface and/or the light incident surface comprises a plurality of optical microstructures;
• wherein the light diffusion plate further has a plurality of diffusion areas, and each of the diffusion areas has eight of the optical microstructures surrounding and adjacent to a point of the diffusion area, a shape of each of the optical microstructures comprises a triangular pyramid, and each of the optical microstructures has an inclined surface, the inclined surface stands on the light emitting surface and/or the light incident surface and is inclined with respect to the light emitting surface and the light incident surface, wherein two inclined surfaces of each adjacent microstructure face each other and form a connection line, an included angle is formed between the two inclined surfaces and the included angle ranges from 30 degrees to 150 degrees, and the connection lines of all the optical microstructures intersect at the point.