SENSOR DEVICE AND METHOD FOR GRIP AND PROXIMITY DETECTION

摘要

An electrical hand-held device is provided with improved proximity detection, which can be placed on a surface and has at least one transmission electrode, at least one reception electrode and at least one compensation electrode arranged between transmission electrode and reception electrode. The transmission electrode and the compensation electrode can be supplied with an electric switching signal of predetermined signal frequency and predetermined signal amplitude. Switching electric signal at the compensation electrode is phase- delayed with respect to the switching electric signal at the transmission electrode. Alternating electric fields radiated at the transmission electrode and the compensation electrode generate a current in the reception electrode, which is representative of an approach of a hand to the hand-held device. The transmission electrode and the reception electrode are arranged in such a way, that the impedance between the transmission electrode and the reception electrode exceeds a predetermined value, which is suitable to keep the current generated in the reception electrode under a predetermined value.