| 摘要 |
<p>PURPOSE:To attain highly accurate and stable position detection with a simple constitution by forming constant current source circuits for fixing current flowing into respective detecting electrodes respectively. CONSTITUTION:A voltage sensitive resistor sheet of an information input device is constituted by applying a conductive layer 2 consisting of a metallic sheet to the upper surface of a voltage sensitive sheet 1 and laminating a plane resistor 3 to its lower surface and detecting electrodes 5a-5d are formed by connecting plural diodes to respective sides of the resistor 3 to detect the coordinates of a depressed position at the time of depression through an indicating pen or the like. Constant current sources 22a, 22b are connected respectively between the electrode 5a and the earth and between the electrode 5b and the earth to fix their outflow currents independently. In addition, operational amplifiers 21a, 21b are connected respectively between the electrode 5a and a terminal 101 to detect the potential difference between both the electrodes 5a, 5b and find out positional coordinates (X, Y). The potential of the electrode 5a is compared with a reference voltage 25 by a comparator 24, and when the former value is larger than the latter one, a Z signal is generated to make said X and Y is signals significant.</p> |
