Provided is a planar lighting device having a thin shape and capable of emitting uniform illumination light with less brightness unevenness. A plurality of thermal vias formed in the die-attach region and penetrating the substrate, in a manner that the thermal vias each has a top end connected to the chip mounted on the substrate and a bottom end connected to a thermal pad formed beneath the substrate at a position corresponding to the die-attach region. A redirect arrangement includes a pivot redirect element driven by the wrist rotation torque motor at one half of the rotational speed at which a first and second wrist element of the articulated wrist apparatus pivot with respect to one another.