Fingerprint scanner
Fingerprint scanners are a type of biometric security device that identify an individual by identifying the structure of their fingerprints. They are used in police stations, security industries, smartphones, and other mobile devices.
Fingerprints
People have patterns of friction ridges on their fingers, these patterns are called the fingerprints. Fingerprints are uniquely detailed, durable over an individual's lifetime, and difficult to alter. Due to the unique combinations, fingerprints have become an ideal means of identification.Types of fingerprint scanners
There are four types of fingerprint scanners:- Optical scanners take a visual image of the fingerprint using a digital camera.
- Capacitive or CMOS scanners use capacitors and thus electric current to form an image of the fingerprint. This type of scanner tends to excel in terms of precision.
- Ultrasonic fingerprint scanners use high frequency sound waves to penetrate the epidermal layer of the skin.
- Thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys.
Construction forms
Each type of fingerprint sensor can take two basic forms: the stagnant and the moving fingerprint scanner.- Stagnant: The scanning module is mounted statically, and the user is required to swipe their fingers across it. This is cheaper but also less reliable than the moving form. Imaging can be less than ideal if the finger is not dragged over the scanning area at constant speed.
- Moving: The scanning module is mounted on a movable surface, while the user's finger can remain static. Because this layout allows the scanning module to pass the fingerprint at a constant speed, this method is generally more reliable.
Form factors