| 摘要 |
<p>PURPOSE:To read coordinates with simple constitution by applying alternately a voltage between the opposite sides of the electrodes of four sides, and reading the coordinates based upon the voltage outputted to the second resistance layer at the time of contacting a pair of the resistance layer. CONSTITUTION:By turning off a switch Sy (equivalent to transistors 15 and 16) and turning on a switch Sx (equivalent to transistors 13 and 14), a voltage E is impressed between terminals X0 and X1. In such a condition, when a P point is pushed down, resistance layers 12a and 12b are brought into contact with each other and at a terminal S, a voltage Vx to partially pressure the voltage E at the P point appears. Since the voltage Vx is proportional to the distance in the X direction, the X coordinates of the P point can be known from the Vx. In the same way, by turning on the switch Sx and turning off the switch Sy, the Y coordinates of the P point can be known from a voltage Vy generating at the terminal S. A micro-computer 17 executes the above- mentioned switch changing-over and can be realized by making the output level of a port PA1 into L or H.</p> |
