| 摘要 |
<p>PURPOSE:To reduce the power consumption by generating an AC magnetic field from an coordinate indicator only in a pen-down state and detecting the coordinate information. CONSTITUTION:The pressure produced with the contact of a pen point to a writing surface 9 is transmitted to a pen-down/pen-up detecting circuit 4 via a pen core 8. When said pressure exceeds a prescribed level, the circuit 4 informs a pen-down state to an oscillation control circuit 3. The circuit 3 controls an alternating current generating circuit 2 and an AC magnetic field is produced from an AC magnetic field generating coil 7 set at the pen point. The AC magnetic field is continuously produced during a pen-down state and therefore an electromotive force timing detecting circuit 11 transmits an electromotive force presence/absence detecting signal 19 to a coordinate information detecting circuit 13 to show the presence of the electromotive force. Thus the power consumption is reduced for a coordinate reading device.</p> |
