Embodiments of the present invention relate to
fingerprint scanning. Specifically, the present invention relates to a multi-sided
fingerprint scanning device on a card (e.g.,
credit card,
smart card, etc.), an associated energy-efficient method for attaining accurate
fingerprint information using a multiple charge-coupled biometric
sensor array. In a typical embodiment, a scanning device will be provided that includes a scanning area comprised of a set (e.g., at least one) of imaging pixel electrodes (e.g., arranged adjacent to one another in a grid-like or other fashion). As a user presses his / her finger against the scanning area, a portion of the finger will contact a plurality of electrodes. When this occurs, a
voltage source of the device will apply a first
voltage to each of the plurality of electrodes. A meter of the device will take a first electrical measurement (e.g., resistance and / or charged
skin voltage) of the plurality of electrodes. The
voltage source of the device will apply a second voltage to the plurality of electrodes. The meter of the device will take a second electrical measurement (e.g., resistance and / or charged
skin voltage) of the plurality of electrodes. The voltage level difference between the first electrical measurement and second electrical measurement is calculated. The voltage level difference provides accurate fingerprint information.