| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a tablet device capable of detecting a signal from a pen and with attractive appearance and provided with an input plane consisting of one layer of detection electrode. SOLUTION: A signal of frequency f1 and a signal of frequency f2 are generated in oscillation circuits 18A, 18b, and a signal on which they are superimposed is generated from the pen 19. While, the signal from the pen 19 is received in capacitive coupling fashion by a large number of parallel detection electrodes 11, and it is inputted to a filter circuit 14A and a filter circuit 14B. The filter circuit 14A passes selectively a signal frequency f1 generated in the oscillation circuit 18A mainly, and the filter circuit 14B passes a signal frequency f2 generated in the oscillation circuit 14B. A two-dimensional position instructed by the pen 19 is calculated by measuring signal strength in each of frequencies, and performing an arithmetic operation by a position calculating means 17.</p> |
