A smart pen including: a body part; a nib part at an end of the body part; a code detection unit for receiving light reflected from a display panel and the nib part, wherein the light reflected from the display panel and the nib part is used to detect shape data for code patterns of the display panel; and a code processor for generating coordinate data based on the shape data and transmitting the coordinate data to a main processor for driving the display panel based on the coordinate data.