| 摘要 |
<p>PURPOSE:To automatically correct and adjust an error due to the influence of fluctuation in a sheet resistance, a constant current source, an operational amplifier and the like and an off set voltage and to improve the productivity of a coordinate reader by connecting the operational amplifiers to the X and Y axes resistance bodies of a touch panel through an analogue switch and controlling them by means of a CPU. CONSTITUTION:Metallic fine wires 54 and 55 are respectively arranged on one side of the insulating substrate of the touch panel in the coordinate reader, and respective one ends of the fine wires 54 and 55 are connected to the X- and Y-axes sheet resistance bodies 52 and 53 at equal intervals. The optional points of confronting the insulating substrate in the panel 1 is depressed and X and Y coordinate signals are outputted from both ends by the contact of the resistance bodies 52 and 53. The signals are inputted to the operational amplifiers 58 and 59 through the first and second analogue switches 64 and 65, and the voltage corresponding to the X and Y coordinates are detected. The switch 64 is connected so that the detection level becomes minimum and the switch 65 is connected so that the level becomes largest.</p> |
