| 摘要 |
<p>PURPOSE:To transmit a required signal simultaneously with erasing of a character by providing an oscillator, which is directed forward and capable of oscillating high frequency oscillating waves having a natural frequency, in the peripheral part surrounding an eraser body in the front part of a case body and connecting the oscillator to an oscillating circuit. CONSTITUTION:An oscillating circuit 17 and a cell 18 like a dry cell are stored in a case body 15, and an oscillator 21 is excited, and the case body 15 is formed into an angular cylinder to surround an erasing felt 16, and high frequency oscillating waves are propagated in air. Detecting circuits 33 are attached to both ends of a high polymer piezoelectric sheet 1, and potentials VL and VR generated in the left and the right are calculated. When the distortion occurrence point of a resistance film 3 is defined as a variable (x), coordinates (x) of the distortion occurrence point at a time t = to are obtained in accordance with VR(to) and VL(to), and the difference between respective signals of counter electrodes 5x and 5x is divided by the sum value to obtain coordinates (x) as displacement from the center point of the resistance film 3. A signal which erases the same characters reproduced on a display device installed in a separate position is issued simultaneously with erase of characters on an electronic blackboard 7 by an eraser 14. Thus, position information of the erase point is given to the electronic blackboard 7 in the state of oscillation distortion while erasing characters.</p> |
