Patent ID: 8044940

Claim:
A display system comprising: a display device with a display surface; and an input device that is able to communicate with the display device, wherein: the input device comprises: a track detection unit that detects a track of points of contact between the input device operated by a user and the display surface; a writing unit that writes track data indicating the track detected by the track detection unit in a memory; and a sending unit that retrieves the track data from the memory and sends the track data to the display device; and the display device comprises: a position detection unit that detects positions on the display surface contacted by the input device and generates drawing data representing a line formed by points on the detected positions; an operation mode change unit that changes an operation mode of the display device from a position detection mode for causing the position detection unit to detect the positions to a position non-detection mode for not causing the position detection unit to detect the positions or vice versa; an instruction unit that, when the display device is in the position non-detection mode, instructs the input device to detect the track; a request unit that, when the operation mode of the display device is changed from the position non-detection mode to the position detection mode, requests the input device for the track data; a synthesizing unit that synthesizes the track data sent from the sending unit of the input device in response to the request from the request unit and drawing data generated by the position detection unit after the operation mode of the display device is changed to the position detection mode, to generate image data; and a display unit that displays an image represented by the image data generated by the synthesizing unit, on the display surface.