Do you know how a fingerprint scanner works?
Despite various security efforts, there is the fear of breaking the lock, and there is the fear of password hacking. But how to protect their wealth? One answer might be, ‘biometrics’.
Fingerprint scanning technology once seen in sci-fi movies can now be found in people’s pockets, secure buildings, ATMs and devices as diverse as smartphones.
As tech site Android Police reports, there are primarily three types of fingerprint scanners. These are ‘optical’, ‘capacitive’ and ‘ultrasonic’. Let’s find out how they work.
Optical fingerprint scanner
The earliest technology for fingerprint identification was the optical fingerprint scanner. Using visible light and imaging devices, this scanner accurately detects fingerprints. This technology captures a photo and converts the image into a digital format to identify fingerprints.
The process relies on microchips that are sensitive to light. It can be a ‘charge coupled device’ or CCD or ‘metal-oxide semiconductor’ (CMOS), which detects fingerprints. Since the highs and lows of the fingerprint reflect light differently, the scanner translates these patterns into binary numbers of ones and zeroes to create an individual and unique ‘digital key’ for each user.
Due to its accuracy and simplicity, the optical fingerprint scanner can be one of the best choices for home or personal gadget use.
However, this scanner has some limitations, the most notable of which is ‘spoofing’. That is, with the necessary skills, it is possible to create false fingerprints, which the scanner often does not catch. Also, dirt, moisture, or oil deposits on the finger or scanner surface can cause errors in the fingerprint recognition process.
Capacitive fingerprint scanner
Capacitive fingerprint scanning technology has been one of the main features of mobile phones for years. This technology became popular with the launch of the iPhone 5S.
In this case, the surface of the scanner is made of a ‘conductive material’, such as copper or ‘indium tin oxide’, the underside of which is connected to the capacitive circuit.
When holding a finger over the scanner, the raised areas of the fingerprint affect the capacitor differently, as this area makes more contact with the sensor. It properly stores the electrical charge in the sensor, which produces an accurate image of the fingerprint.
Capacitive scanners work well on smartphones and laptops due to their compact or compact nature. In addition, it has additional security advantages compared to optical scanners. In this case ‘spoofing’ is not easy. This scanner also has the added benefit of detecting finger movements.
Ultrasonic fingerprint scanner
Ultrasonic sensors bring a touch of new and ‘premium’ innovation to this sector. Although this technology is relatively expensive, it is paving the way for advanced ‘in-display’ fingerprints in mobile phones. This technology works in a similar way to ultrasonography.
The sensor sends ultrasonic pulses to the finger, which are sound waves that humans cannot hear. The unique pattern of fingerprints creates different ‘echo intensities’ or echoes when exposed to these vibrations. And the sensor translates these echoes into a 3D fingerprint map
Unlike ‘2D’ fingerprints produced by optical and capacitive sensors, ultrasonic sensors produce advanced ‘3D’ fingerprints. This makes the ultrasonic sensor more accurate and more secure against ‘spoofing’ attempts, Android Police wrote in the report.
Also, this sensor can scan accurately even if there is dirt, oil or moisture on it. As a result, they are slightly more expensive than optical and capacitive sensors. And for accuracy, this ultrasonic sensor detects fingerprints in slow motion.
What is the function of the software in the finger print scanner?
Fingerprint scanners are differentiated by software and additional features, which affect the performance and various features of these sensors. Different companies develop fingerprint recognition algorithms differently, resulting in variations in features including speed and accuracy.
For example a key component is the ‘IC’, which processes the scanned data. Algorithms are used to identify various features of fingerprints. This process reduces the required power requirements as well as makes the feature more reliable.
Limitations of fingerprint technology
Optical scanners are fast and can be placed below the display screen, but in many cases these scanners are easy to fool. Meanwhile, the equally fast and more secure capacitive scanner cannot be hidden under the screen. In comparison, ultrasonic scanners strike a balance between walking speed, good safety and the ability to work under glass, unless the high cost of these scanners is considered. Many people these days may be confused about these fingerprint features, but one should choose carefully, choose only the essential features, don’t worry too much about what is unnecessary.
