Laser Image Calibration Technology FT3000 with two parts: emitter and sensor. Emitter can be attached on flat surface. It emits infrared laser curtain on the surface which is about 1mm thick invisible light and parallel with the projection screen surface, 1-2mm above the screen surface. When the fingers or any non-transparent objects touch this virtual surface, the light will be reflected and detected by the sensor. Computer will figure out the position of the mouse by accurate calculating the reflected light position.
Single finger is for "Write", Two fingers for "move", "zoom in or out" and "scroll bar", Palm for "Erase",Palm stay 2s for Spot, Palm two clicks for back to desktop.
Ten points touch, write and eraser can do together.