Patent ID: 6281888
Filing Date: 2001-08-28
Classification: G06F

Abstract:
A pen input device for sensing the position of a tip of a writing instrument regardless of whether the writing instrument includes electrical components, comprising:an array of electrodes, at least some electrodes being receive electrodes generating a respective received signal characterized by a signal strength, at least one of the electrodes being selectable in a cycle as a transmitting electrode for coupling transmitted signals into a person's hand; anda processor connected at least to the array, whereby a person can use the writing instrument to write on a substrate positioned on the array, the transmitting electrode being selected by the processor such that the transmitted signals are coupled to the person's hand when the person writes on a substrate, the processor receiving at least some of the received signals and determining a position of the tip based at least in part on the signal strengths, the processor discriminating signals from the array generated by hand contact from signals generated by writing instrument contact and selecting a transmitting electrode at least partially based thereon.