摘要 |
The sensor is provided for the capacitive acquisition of images, in particular fingerprint images. The capacitors assigned to each pixel are supplemented by reference electrodes which are capacitively coupled to one another with coupling capacitances. Parallel acquisition of the image with the measuring electrodes and the additional reference electrodes yields, on the one hand, an image subdivided in accordance with the grid, and, on the other hand, local averaging resulting from the capacitive coupling is performed, which is used as a local reference value. |