The present invention relates to a smart pen (20) and a display device (10) using the same, in which a reflective light reception rate may be enhanced through a light output structure to increase a code pattern (CP) and code information recognition rate of a display panel (100). According to an embodiment of the invention, the smart pen (20) comprises a body portion (26), a pen tip portion (27) formed on one end of the body portion (26) to form a path of light emitted from a light emitting portion (21(a)) in an end direction at one side, a code detector (21) detecting shape data for code patterns (CP) by applying light to the pen tip portion (27) and receiving light reflected from the display panel (100) and the pen tip portion (27), and a code processor (23) generating coordinate data by using the shape data and transmitting the coordinate data to a main processor (500) for driving the display panel (100).