Patent ID: 8896532

Claim:
A method for controlling an interactive display device, the method comprising: detecting an external device on a surface of the interactive display device, wherein the external device includes a plurality of identification markers sensed by the interactive display device; scanning a shape of the external device; sensing signals of the identification markers; determining coordinate information and contact information of the external device on the surface of the interactive display device based on a result of scanning the shape and sensing the signals, wherein the contact information indicates which side of the external device is in contact with the interactive display device; and displaying data around the external device according to the determined coordinate information and contact information, wherein a result of scanning the shape of the external device is an image including a gradation region, wherein a tilt angle of the external device is determined according to a brightness ratio of the gradation region, and wherein a direction of the external device is determined according to a direction of the gradation region.