| 摘要 |
<p>PURPOSE:To prevent the malfunction when plural pieces of equipment are used in an approximate condition by providing a resonance circuit at plural markers with a pen and executing the action of a prescribed mode with a characteristic frequency respectively. CONSTITUTION:When any of makers 2-4 with a pen and an eraser 5 is contacted to a writing surface 15 of a blackboard 1 with pressure, the frequency characteristic of the resonance circuit built in the said markers, etc., is communicated through an antenna coil 14 for receiving to a writing material discriminating circuit 7. The circuit 7 sends an alternating current signal to an antenna coil 13 for transmission, the radiation electric wave from the coil 13 is received with the marker, etc., the resonance induced voltage is communicated through the coil 14 to the circuit 7 and the circuit 7 identifies the said marker, etc. Under the control of the circuit 7, the coil is initialized after the action with the continuous mode of the trigger channel receiving/transmitting and discriminating sense. By the signal from a tablet 12, a position detecting circuit 6 sends the coordinate value such as the marker to a picture processing device 8 and the device 8 stores the picture data in accordance with the output information of the circuit 7.</p> |
