HOW FINGER PRINT SENSOR WORKS?By Jain Software In Business, Official Blog, Tech-BLOG, Technical
A finger print sensor is an electronic device used to capture a digital image of finger print pattern. The captured image is called a live scan. This live scan is digitally process to create the biometric template which is stored and used for matching. Many technologies have been used including optical, capacitive, RF, thermal, ultrasonic, piezoelectric, mems. Fingerprints offers a complete range of technology for working with fingerprint biometrics that can be used separately or in combination, including sensors, biometric processors, and modules. The competitive advantages offered by Fingerprints’ technology include unique image quality, extreme robustness, low power consumption, and complete biometric systems. Fingerprints’ area sensor and swipe sensor are both based on patented proprietary technology, which offers several strong advantages such as high image quality, programmable pixel elements, and 256 gray-scale values from every single pixel element. The sensors contain small capacitive plates, each with their own electrical circuit embedded in the chip. The sensors use Fingerprints’ proprietary HSPA (High Sensitive Pixel Amplifier) that allows each pixel element in the sensor to detect very weak signals, which improves image quality for all types of fingers. Extremely weak electrical charges, sent via the finger, are created, building a pattern between the finger’s ridges or valleys and the sensor’s plates. Using these charges, the sensor measures the capacitance pattern across the surface.
Fingerprints’ HSPA method also allows the use of a patented protective coating that is 25 to 30 times thicker than other suppliers and helps Fingerprints’ sensors to withstand values. Capacitance is the ability to hold an electrical charge. Fingerprints’ sensors contain tens of thousands of small capacitive plates, each with their own electrical circuit embedded in the chip. When the finger is placed on the sensor, extremely weak electrical charges are created, building a pattern between the finger’s ridges or valleys and the sensor’s plates. Using these charges, the sensor measures the capacitance pattern across the surface. The measured values are digitized by the sensor and sent to the neighboring microprocessor. The surface of a capacitive sensor is a neat array of plates that are able to measure the capacitance between these plates and thus the finger print contour. This can be above directly by applying an electrical charge to the plate.