US Patent 7831070 Dynamic finger detection mechanism for a fingerprint sensor

The present invention discloses an apparatus for determining the presence of a patterned object on the surface of a sensor. The apparatus comprises a sensor system coupled to a means for generating a control signal. The sensor system is configured to sense an image corresponding to the patterned object and to translate the image into image data. The means for generating a control signal generates a control signal if statistics of the image data exceed a pre-determined number of threshold levels. In a preferred embodiment, the patterned object is finger with a fingerprint on its surface and the sensor is fingerprint swipe sensor. Preferably, the threshold levels are software programmable.