Backlight module

A backlight module, comprising:

• a light guide plate having a bottom surface, a light emitting surface, a first light incident surface, and a plurality of microstructures, wherein the bottom surface and the light emitting surface are opposite to each other, the first light incident surface is connected to the bottom surface and the light emitting surface, each of the microstructures only protrudes from the bottom surface, each of the microstructures has a first surface and a second surface, the first surface and the second surface of at least one of the microstructures are located on two sides of a first reference plane parallel to the first light incident surface, wherein a section-line of each of the first surfaces on a second reference plane perpendicular to the first light incident surface and perpendicular to the light emitting surface is a straight line, a first angle included between each of the first surfaces and a third reference plane parallel to the light emitting surface in the light guide plate is between 0 degrees and 20 degrees, a section-line of each of the first surfaces and each of the second surfaces on the third reference plane is only a curved line, and a thickness of each of the microstructures in a direction perpendicular to the light emitting surface is between 0 micrometers and 20 micrometers;
• a reverse prism sheet located on the light emitting surface;
• and
• a first light source located adjacent to the first light incident surface.