A linkage mechanism includes a pivoting assembly, a cam, a sliding assembly, and a linkage assembly. The cam pivots coaxially with the rotating axis. The sliding assembly is assembled on a plate member and has a leaning surface and a sliding slot. The linkage assembly includes a linkage passing through the sliding slot and a carrier base including at least one bump and fastened to the linkage. When the pivoting assembly drives the cam to pivot from a first position to a second position, the cam pushes against the leaning surface to slide the sliding assembly relative to the plate member in a first direction, and the linkage rotates in the sliding slot to drive the carrier base to move in a second direction, and the bump gradually enters into a cavity of a frame from leaning the frame to move the frame in a third direction.