COORDINATE DETECTING METHOD FOR LOADING DETECTION TYPE COORDINATE INPUT DEVICE

摘要

PURPOSE:To reduce the error of the X and Y down to a certain level or less regardless of the value of the force of application, by starting an operation to obtain the coordinate value at the point where the force is applied when one area of the electric signal corresponding to the component force detected at the three fulcra exceeds the prescribed threshold level. CONSTITUTION:The components fa-fc supplied from three fulcra of the loading detection type coordinate input device are converted into the electric signals via the force detectors 2a-2c and then added via the adder 6 after an amplification via amplifiers 3a-3c each. The result of the addition is applied to the comparator 7 to be compared with the threshold voltage VREF. And in case the applied force is increased and the result of comparison is higher than the voltage VREF, the FF8 is turned on. In this instant, the calculation start command signal is applied to the computer 5, and the computer 5 applies the calculation start indication to the A/D converter 4. And a calculation is startd to obtain the coordinates of X and Y from the outputs of amplifiers 3a-3c. Then the FF8 is turned off by the control signal supplied from the computer 5 after completion of the calculation.