Patent ID: 8890828

Claim:
A digitizer, comprising: an input unit having a magnetic field shielding part embedded therein; a driving coil supplied with current to induce a magnetic line of force; a sensing coil to which voltage is induced by the magnetic line of force; and a control unit supplying current to the driving coil and measuring voltage induced to the sensing coil, wherein the control unit senses variation of voltage induced to the sensing coil to calculate coordinates of the input unit when the voltage induced to the sensing coil is changed by the magnetic field shielding part, and wherein a magnetic field formed in the driving coil and inducing the voltage to the sensing coil is absorbed or reflected, a magnetic flux density and a magnetic flux direction are changed, the induced voltage of the sensing coil is changed in comparison with the one before that the input unit approaches, and the driving coil and the sensing coil perpendicularly intersect with each other.