Patent ID: 8449163

Claim:
A backlight module comprising: at least one light emitting device capable of emitting a light beam; a light guide plate having a first surface, a second surface opposite to the first surface, and a side surface connecting the first surface and the second surface, wherein the light emitting device is disposed beside the side surface, and the light beam is capable of entering the light guide plate through the side surface; and a thermal insulation light guide element having: a light incident surface located in a transmission path of the light beam and between the light emitting device and the side surface, wherein the light incident surface has at least one first recess; and a light emitting surface located in the transmission path of the light beam and between the light incident surface and the side surface, wherein a glass transition temperature of the thermal insulation light guide element is higher than a glass transition temperature of the light guide plate, wherein the light emitting surface of the thermal insulation light guide element comprises a plurality of second recesses and a plurality of protrusions, the second recesses and the protrusions are aligned along a reference straight line, the second recesses are disposed on a central region of the light emitting surface, and the protrusions are disposed on two sides of the light emitting surface, wherein an extension direction of the reference straight line is perpendicular to a direction of the light beam emitted from the first surface of the light guide plate.