An exemplary elevator (50) includes a support mechanism (51), an elevating mechanism (52), and an adjusting mechanism (53). The support mechanism includes a support bracket (511) and a coil spring (514). The elevating mechanism includes a rotatable member (521) rotatable attached to the support bracket, a driven member (524) fixed to the rotatable member, a sliding bracket (526) slidably connected to the support bracket, and a sliding member (527) fixed to the sliding bracket. The sliding member is capable of engaging with the rotatable member for converting rotation to linear motion. The adjusting mechanism includes a diver capable of engaging with the driven member and driving the driven member to rotate. A bottom end of the support bracket is fixed to the adjusting mechanism. An end of the coil spring is fixed on the sliding bracket, and another end of the coil spring is connected to the support bracket.