Fingerprint scanners work by optically or capacitively reading the unique ridge and valley patterns of fingerprints. Optical scanners use cameras to capture fingerprint images while capacitive scanners use semiconductor chips containing arrays of cells to detect ridge patterns. Both analyze fingerprints by measuring the positions of minutiae points, where ridges end or bifurcate, using complex algorithms to recognize and match fingerprints for identification purposes in security and criminal investigations.

1. How Fingerprint
Scanners Work
Group D
S1190017 Jun Kikuchi

2. Introduction
• Fingerprint scanner usually uses in
police station, high-security building,
and so on.
• Now fingerprint scanner is less than
$100, so you use high-tech biometrics
easily .

3. Fingerprint Basics
• Fingerprint which go into deciding your genetic
make-up has a unique design.
• A Fingerprint scanner reads the pattern of ridges
and valleys on fingers.
• A fingerprint scanner is to discriminate
someone in both crime investigation and
security.

4. Optical Scanner
• Optical scanning is way to get a image of a
finger and to determine whether the pattern of
ridges and valleys.
• Optical scanning and capacitance scanning is a
charge coupled device (CCD) ; it is simply an
array of light-sensitive diodes.

5. Capacitance Scanner
• A simple capacitive sensor is made up of one or
more semiconductor chips containing an array
of tiny cells ; tiny cells include two conductor
plates.
• To scan the finger shorts each
amplifier’s input and output to
balance the integrator circuit.

6. Analysis
• Mimutiae -> concentrate on points where ridge
lines end or where one ridge splits into two
(bifurcations).
• The scanner system software uses highly
complex algorithms to recognize and to measure
the relative positions of minutiae.