1. A rollable display device, comprising:a roller configured to be rotatable;
a fixing portion surrounding the roller and including a first slit;
a rotating portion surrounding the fixing portion and including a second slit;
a gear assembly including a plurality of gears installed in the roller, the fixing portion, and the rotating portion, wherein the plurality of gears is configured to transfer torque of the roller to the rotating portion; and
a flexible display panel including a first area positioned between the roller and the fixing portion of which one end is fixed to the roller, a second area positioned to pass through the first slit, and a third area extended from the second area.