Planar illumination device

A planar illumination device comprising:

• at least two light sources;
• at least two housing structures respectively receiving the at least two light sources therein, wherein the at least two housing structures each comprise a light emitting surface through which the light emitted from the at least two light sources exits the at least two housing structures;
• at least one light guide plate comprising at least two light incidence surfaces through which the light enters into the at least one light guide plate, the at least two light incidence surfaces respectively contacting with the light emitting surfaces of the at least two housing structures;
• at least one light exiting surface through which the light exits the at least one light guide plate, wherein the at least one light exiting surface comprises a plurality of continuously connected bulge points formed thereon, and the diameters of bottom ends of the bulge points at the at least one light exiting surface of the at least one light guide plate gradually increase from a position adjacent to the at least two light sources towards a position away from the at least two light sources;
• and
• a metallic connecting plate;
• wherein the at least two light sources comprise two light sources, and the at least two housing structures comprise two housing structures, and wherein the two housing structures are parallel to each other, the metallic connecting plate is located between and contacts with the two housing structures, and the two light sources are electrically connected with each other via the metallic connecting plate.