| 摘要 |
<p>PURPOSE:To improve S/N and the coordinate detection accuracy by constituting this device so that when many pieces of loop coils which are connected to a common line and provided in parallel, respectively are brought to switching connection to a receiving circuit by a time division and a receiving signal is fetched, it is always fetched by using the loop coils of three pieces each. CONSTITUTION:An oscillation use loop coil 1 and a receiving use loop coil 2 are placed separately on a coordinate input use detection board, and an X axis board and a Y axis board are crossed and placed on the surface and the reverse side of the detection board. The oscillation use loop coil 1 and the receiving use loop coil 2 are connected to a transmitting circuit 5 and a receiving circuit 5, respectively, and in an induction coil L of an input pen 30 or a cursor, an induced voltage is allowed to occur by an electromagnetic induction and a capacitor C connected to the induction coil is charged, and the charge of the capacitor C is discharged to the induction coil L. In such a way, a receiving signal flowing to the receiving use loop coil is fetched, and a contact coordinate position of the input pen or the cursor is calculated. In such a case, the receiving use loop coil is used so as to pick up a receiving signal by a loop constituted of three pieces each. In such a way, the S/N and the coordinate detection accuracy can be improved.</p> |
