Fingerprint detector using ridge resistance sensor

A method for detecting and verifying a fingerprint comprising the steps of:

• providing a fingerprint verification terminal;
• providing a skin resistance sensing array coupled to the fingerprint verification terminal, the skin resistance sensing array translating skin resistance of a fingertip into an electrical signal;
• moving the fingertip relative to the skin resistance sensing array in a first linear direction for producing a reference trajectory signal;
• encoding the reference trajectory signal onto a data carrier card;
• moving the fingertip relative to the skin resistance sensing array in a second linear direction for producing a sample trajectory signal, the second linear direction being offset from the first linear direction by a predetermined angle;
• reading the reference trajectory signal from the data carrier card into a memory;
• providing a processor for performing a set of functions on the reference trajectory signal and the sample trajectory signal;
• correlating the sample trajectory signal with the reference trajectory signal;
• and
• producing a verification signal related to the probability that the fingertip generated both the sample trajectory signal and the reference trajectory signal.

A method for detecting and verifying a fingerprint comprising the steps of:

• providing a skin resistance sensing array, the skin resistance sensing array translating skin resistance of a fingertip into an electrical signal, and further including a plurality of sensing elements, at least two of the sensing elements being used for generating a velocity function;
• moving the fingertip relative to the skin resistance sensing array in a first linear direction for producing a reference trajectory signal;
• storing the reference trajectory signal in a memory;
• moving the fingertip relative to the skin resistance sensing array in a second linear direction for producing a sample trajectory signal, the second linear direction being offset from the first linear direction by a predetermined angle;
• providing a processor for generating an intersection matrix of common data points relating to the reference trajectory signal and the sample trajectory signal;
• correlating the common data points of the sample trajectory signal with the reference trajectory signal;
• and
• producing a verification signal related to the probability that the fingertip generated both the sample trajectory signal and the reference trajectory signal.