Coordinate input device with display

摘要

A coordinate input device with a display includes a position detecting tablet having a plurality of X-direction magnetostrictive transmission mediums and a plurality of Y-direction magnetostrictive transmission mediums superposed orthogonally, a first coil wound around one end of the array of magnetostrictive transmission mediums, and a second coil wound over substantially the entire lengths of the magnetostrictive transmission mediums. A position indicated on the tablet by a position indicating magnetism generator is detected by measuring the length of time between the moment at which a pulse current is applied to one of the first and second coils and the moment at which the voltage induced in the other of the first and second coils by a magnetostrictive vibration wave exceeds a threshold value owing to the sudden increase of voltage observed when the wave passes the indicated position. The coordinate input device further has a display unit which is superposed on the tablet and is adapted to directly display the position indicated on the tablet at the corresponding position thereon.