2. What are Fingerprints?
People have tiny ridges of skin on their fingers
They help the fingers grip things, like the rubber
thread pattern on a tire help grip the road
There is no chance that the same exact pattern
forming twice
3. What does a Fingerprint Scanner Do?
It has two basic jobs
It first gets an image of the person’s finger
Then it needs to match the pattern of the ridges and
valleys in that imagine with an the pattern of a pre-
scanned images.
4. How do you get an Image of a Somebody’s
Finger?
The two most common methods are
Optical Scanning
Capacitance Scanning
5. Optical Scanning
It starts when a person places their finger on a glass
plate, and a CCD (Charged Coupled Device) camera
takes a picture.
The CCD system generates an inverted image of the
finger with darker areas representing the ridges of
the finger and lighter areas representing the valleys
between the ridges.
6. Optical Scanning Cont.
After it proceeds to comparing the captured
fingerprint with fingerprints on file.
7. Capacitive Scanner
It starts out like an optical scanner but instead of
sensing the print using light, it uses an electrical
current.
A finger ridge will result in a different voltage output
then a finger valley.
The scanner processor will put together an overall
picture of the finger print
