Light guide plate and backlight module

A backlight module, comprising:

• a light guide plate, having a light emitting surface, a bottom surface opposite to the light emitting surface, and at least one light incident surface contacting with the light emitting surface and the bottom surface, wherein the bottom surface comprises:
• a plurality of flat surfaces;
• and
• a plurality of groove groups, wherein the flat surfaces and the groove groups are arranged alternately from a first end of the bottom surface contacting with the light incident surface to a second end of the bottom surface opposite to the first end of the bottom surface, each of the groove groups has at least two grooves, each of the grooves has a first slanted surface, a peak, and a second slanted surface intersecting with the first slanted surface at the peak, and in each of the grooves, a first edge side of the first slanted surface away from the peak is at a first distance from a second edge side of the second slanted surface away from the peak, wherein a second distance is between each two neighboring peaks of each groove group, each of the groove groups has a specific value calculated by dividing a difference of the second distance minus the first distance by the first distance, and each of the groove groups from the first end of the bottom surface to the second end of the bottom surface satisfies that the specific value is greater than 0 and smaller than 1;
• and a light source, disposed adjacent to the light incident surface.