A winding shaft structure includes a winding shaft holder rotatable around an axial direction of the winding shaft structure, a first shaft group connected to one side of the winding shaft holder in the axial direction and configured to rotate together with the winding shaft holder, a second shaft group disposed on a side of the first shaft group in a radial direction of the winding shaft structure, a connecting member connected between the first shaft group and the second shaft group such that the second shaft group is movable with respect to the first shaft group in the radial direction via the connecting member, and a piezoelectric adjustment member disposed between the first shaft group and the second shaft group and deformable in the radial direction to adjust a distance between the first shaft group and the second shaft group.