Access authorisation based on finger print recognition

摘要

The finger print recognition system has a detector (10) formed of a matrix of ferro-electric elements integrated on a silicon substrate. The silicon substrate incorporates an integrated multiplexer circuit allowing individual measurement of the electric charges created in the ferro-electric elements when a finger is pressed onto the surface. The ferro-electric elements are formed by a network of electrodes (28) integrated on the substrate and from a layer of a pyroelectric polymer (30) deposited on the electrode network. The matrix is encapsulated in a box (14) open on one face to accept the user's finger. The matrix delivers a pattern of electrical signals, which provide the image of the finger print for comparison with an authorised print.