| 摘要 |
<p>PURPOSE:To realize a wireless coordinate reader where it is unnecessary to connect a coordinate indicator to a coordinate reader main body. CONSTITUTION:A tablet 1 generates an AC magnetic field by a first exciting circuit. A coil 81 of a coordinate indicator 8 is connected to a power supply circuit 83 by a switching circuit 82. The power supply circuit 83 rectifies an induced signal induced in the coil 81 to store it in a capacitor 84. When sufficient energy is stored, the power supply circuit 83 gives energy to a second exciting circuit 85, and the switching circuit 82 connects the coil 81 to the second exciting circuit 85. Since the coil 81 generates the AC magnetic field, an induced signal corresponding to the position of the coordinate indicator is induced in a loop line group 2. A loop line is selected by a scanning circuit to lead an induced signal s1 to a signal processing circuit 6, and it is inputted to a control circuit 7 to calculate the coordinate value.</p> |
