People have a pattern of ridges on their fingers. This fingerprint cannot be removed or changed. Every fingerprint is different from any other in the world. Because there are countless combinations, fingerprints are much used for identification.
Types of fingerprint scanners[change | change source]
There are four types of fingerprint scanners: the optical scanner, the capacitance scanner, the 'ultrasonic scanner' and the thermal scanners. The basic function of these three types of scanners is to get an image of a person’s fingerprint and find a match for this print in the database. The capacitance scanner is better, because the images are more exact and precise.
- Optical scanners take a photo of the fingerprint using a digital camera.
- Capacitive or CMOS scanners use capacitors and thus electrical current to form an image of the fingerprint.
- Ultrasound fingerprint scanners use high frequency sound waves to penetrate the epidermal (outer) layer of the skin.
- Thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys (patterns of fingerprint).
Construction forms[change | change source]
There are two construction forms: the stagnant and the moving fingerprint scanner.[source?]
- Stagnant: The finger must be dragged over the small scanning area. This is cheaper and less reliable than the moving form. The image is not very good when the finger is not regularly dragged over the scanning area.
- Moving: The finger lies on the scanning area, while the scanner runs underneath. Because the scanner runs regularly over the fingerprint, the images are better.
Popular models[change | change source]
- Lumidigm Mercury M301
- Suprema BioMini
- Verifi P5100
- Futronic FS80#
- Futronic FS88
- Fingkey Hamster II
- Verifi P2000
- Secugen Hamster Plus
- Thumbprint Security USB Reader
- Digital Persona U.are.U 4500