Backlight module and liquid crystal display device

A backlight module, at least comprising a light source assembly and a light guide plate, characterized in that:

• the light source assembly providing multiple groups of parallel incident beams having different intensity, the light guide plate comprising a light incidence surface facing the light source assembly, a bottom surface adjacent to the light incidence surface and a light-emitting surface opposite to the bottom surface, the light incidence surface being used to receive the parallel incident beams from the light source assembly and to refract the parallel incident beams to be multiple groups of parallel refracted beams corresponding to the parallel incident beams onto the bottom surface, the parallel refracted beams being emitted out from the light-emitting surface after being reflected and dispersed by the bottom surface, wherein the bottom surface of the light guide plate is divided into multiple regions, which are corresponding to the parallel incident beams, to separately receive the parallel refracted beams corresponding to the parallel incident beams;
• wherein the light source assembly comprises a light-emitting unit and a light path-adjusting element, the light-emitting unit employing one or more light-emitting diodes, and the light path-adjusting element employing one or more condensing lenses or cylindrical lenses, the luminance of the parallel incident beams provided by the light source assembly being gradually increased from bottom to top along the light incidence surface of the light guide plate;
• wherein the more the parallel incident beams are near to the lower of the light incidence surface of the light guide plate, the weaker the light intensity thereof is, and the more the parallel incident beams are near to the upper of the light incidence surface of the light guide plate, the stronger the light intensity thereof is.