| 摘要 |
<p>PURPOSE:To read assuredly the coordinates through a simple constitution, by providing a tablet containing loop coils distributed equidistantly and a cursor storing a conduction coil and then reading the coordinates of the cursor with the induced electromotive force of the loop coil. CONSTITUTION:A rectangular tablet 1 contains (n) units of loop coils arranged equidisitantly and with overlap with each other. Each loop coil is connected to the input terminal of an A/D converter 4 via analog switches 31-3n respectively. An oscillating pulse is applied to a coil 6 stored in a cursor 5 from a pulse oscillator 7. The output of a converter 4 is supplied to a microcomputer 8. The computer 8 delivers a switch control signal S to the switches 31-3n respectively and at the same time the timing signal T to the oscillator 7. Then the position of the coil 6, i.e., the cursor 5 is read from the electromotive force of all loop coils.</p> |
