whiteboard 4 x 6.The working principle of the electronic whiteboard is divided into two principles: the pressure sensing principle and the laser tracking principle. A touch-type whiteboard using the principle of pressure sensing is equivalent to a touch screen of a computer, and is a human-machine interactive input device that performs a designated work by using a finger or a pen to touch an option displayed on the screen. This has two internal sense of laminated whiteboard, a point when the board's surface under pressure, causing a short circuit of the two films, at this point copyboard control unit detects the coordinate values of the point pressed (touched by the pen or finger Location), sent to the computer via RS232 interface . A laser emitter on each side of the upper end of the whiteboard using the laser tracking principle. After the whiteboard is started, the laser emitter emits a laser to scan the surface of the whiteboard, and the special pen has an inductive laser function to feed back the position of the pen.