| 摘要 |
<p>PURPOSE:To calculate the height of a pen with high accuracy by using the periodical errors produced when the location of an energizing device is obtained on a tablet. CONSTITUTION:The lead wires 11, 12, 111 and 112 are set with spaces secured every P/8 pitch. The phase amplitude error produced when a pair of wires 11 and 12 is selected varies periodically in P/4 pitch. So is with selection of a pair of wires 111 and 112. In this case, however, the characteristics of the amplitude error have the changes of adverse polarities to each other owing to the P/8-pitch shift to both wires 11 and 12. The errors of adverse polarities are eliminated with each other. Thus the average value between the phase modulated signal amplitude obtained from selection of a pair of wires 11 and 12 and that obtained from selection of a pair of wires 111 and 112 is defined as the height Z of a pen.</p> |
