Patent ID: 7109726
Filing Date: 2006-09-19
Classification: G01D,G01V,H03K

Abstract:
1. An object sensing system, comprising: a first electric field sensing transmission electrode; an electric field sensing reception electrode; a driving circuit for driving the first electric field sensing transmission electrode so as to generate a first electric field; an electric field generating object including a second electric field sensing transmission electrode and means for driving the second electric field sensing transmission electrode so as to generate a second electric field; and a current sensing circuit for distinguishably sensing currents induced in the electric field sensing reception electrode by the first electric field and the second electric field, wherein the first electric field sensing transmission electrode and the electric field sensing reception electrode are arranged such that a first object placed in the vicinity of the first electric field sensing transmission electrode and the electric field sensing reception electrode causes a variation in the current induced in the electric field sensing reception electrode by the first electric field, and wherein the current sensing circuit is adapted to sense the first object from the variation in the current induced in the electric field sensing reception electrode by the first electric field and to sense the electric field generating object from a variation in the current induced in the electric field sensing reception electrode by the second electric field.