Abstract: A backlight module including a light guiding plate, a light source and a block is provided. The light guiding plate includes a first surface, a second surface opposite to the first surface, a light incident surface connecting to the first surface and the second surface, and a side surface opposite to the light incident surface. A thickness of at least part of the light guiding plate decreases progressively from the side surface towards the light incident surface. The light source is disposed beside the light incident surface and is capable of emitting a light beam into the light guiding plate through the light incident surface. The block is disposed beside the side surface and includes a reflecting surface facing towards the side surface. The reflecting surface is a concave surface on the block, and the reflecting surface is capable of reflecting the light beam returning to the side surface.

Abstract: A reflector, a light source module, and a display device are disclosed. The reflector includes a substrate and slant reflecting surfaces disposed on the substrate and arranged from a first side to an opposite second side of the reflector. Each slant reflecting surface has an arc-shaped orthogonal projection on the substrate and is not parallel to the substrate. The light source module includes a light guide plate, a light emitting device, and the reflector, and the display device further includes a display panel. The light guide plate has a first surface, at least one opposite second surface, and a light incident surface connecting therebetween. The reflector is disposed at one side of the second surface. The slant reflecting surfaces are parallel to the second surface but not parallel to the first surface. The reflector offers improved luminous efficiency, and the light source module and the display device offer improved brightness.