A small-sized pen-shaped input apparatus precisely detects handwriting input. The apparatus compensates for the effects of the inclination of the pen-shaped input apparatus. An initial inclination angle calculating section calculates the initial value of the inclination angle of a pen shaft in a gravity...http://www.google.es/patents/US5902968?utm_source=gb-gplus-sharePatente US5902968 - Pen-shaped handwriting input apparatus using accelerometers and gyroscopes and an associated operational device for determining pen movement
Pen-shaped handwriting input apparatus using accelerometers and gyroscopes ...
