| 摘要 |
PURPOSE:To detect a pressing block and the position in the block, to perform sampling in the X direction and Y direction simultaneously and to prevent the occurrenc of input error by measuring a current that flows into and flows out from each block of upper and lower multiple electrode resistance sheets. CONSTITUTION:Plural wire electrodes 22 are formed in parallel on the first resistance film to form the first multiple electrode resistance sheet 21, plural wire electrodes 25 are formed on the second resistance film by intersecting this wire electrode 22 at right angles to form the second multiple electrode resistance sheet 24. A Y-direction detecting resistances 27a, 27b and an X-direction detecting resistances 29a, 29b are connected to terminals 23, 26 of blocks of electrodes 22, 25 of sheets 21, 24 through a Y-direction changeover switch 30 and an X- direction changeover switch 31. Flowing in and flowing out of current of resistances 27a, 27b and resitances 29a, 29b are detected by Y-direction and X-direction differential amplifiers 34, 32. The action of switches 30, 31 is selected by X-direction and Y-direction changeover switch controlling circuits 36, 37 to prevent the occurrence of an input error. |
