A: 1. Recalibration. Hold the pen as far to the nib as possible on the center of the calibration dot. The angle between the pen and the screen needs to be 90 degrees. Try to prevent the hands or other opaque objects from blocking the infrared frame, to avoid the inaccurate touch after calibration.
2. Check the resolution of the projector and the computer. A mismatch of resolution between computer and projector will cause inaccurate touch.
(1) Change the computer’s resolution to 1024*768, and check whether the touch or ink is accurate after recalibration;

(2) Unplug the HDMI or VGA cable that connects the computer to the projector, and adjust the resolution of the computer to 1024*768; plug in the output cable of the projector to connect to the computer, then adjust the resolution to 1024*768 and recalibrate it to check if the ink is accurate.