WIRELESS SYSTEM DIGITIZER

PURPOSE:To make a cursor and a digitizer into a wireless mode by providing an auxiliary grid to the coil of the cursor. CONSTITUTION:For a digitizer, an auxiliary grid plate 140 is provided on a reading grid 11 arranged at a reading grid plate 110, and further, an auxiliary grid 14 is arranged on this so as to surround the above-mentioned recording grid 11. The auxiliary grid 14 is used by compensating the phase delay as a reference phase signal since the induced voltage of the same phase as the exciting current of a cursor coil 21 occurs when the cursor coil 21 exists in the internal part. Thus, for a digitizer device, a cursor 2 has the coil 21 and a driver 28, an oscillator 26 and a power source 25 are equipped and the coil 21 is driven. At the above-mentioned reading grid 11, the induced voltage of the phase in accordance with the position of the coil 21 occurs, the induced voltage having the reference phase of the coil 21 occurs at the auxiliary grid 14, both voltages are processed by a control means 21 and the position coordinate value of the coil 21 is outputted.