How an In-display Fingerprint Scanner works

An in-display fingerprint is (literally) embedded under a smartphone’s display uses an optical fingerprint sensor (see other types of fingerprint sensors) to capture and identify users fingerprint information.

This particular type of fingerprint sensor that works under that screen was pioneered by Synaptics, a California-based manufacturer of fingerprint biometrics technology for smartphones and also, touchpads for laptops. Synaptics developed the ‘Synaptics Clear ID sensor’ (named the Clear ID FS9500). The Clear ID is the first-ever optical in-display fingerprint sensor and mass produced it for Vivo to use on the Vivo X20 Plus UD.

First off, in-display fingerprint sensors (Clear ID) are produced to work with OLED panels and not on any other smartphone display technologies. This explains why you’d find the in-display fingerprint sensor only on smartphones with OLED display.






Literally, when you place your finger on the device, a light is shone on your finger, the sensor then proceeds to capture your fingerprint and the device is unlock. Technically, in-display fingerprint sensors work by using the light emitted from the gaps between the pixels of the OLED panel. When a hser places a finger on the sensor, this light illuminates the fingerprint and ultimately captures it

A (very) high resolution image of fingerprint is taken and an algorithm proceeds to detect unique patterns of your prints by thoroughly analyzing every part of the captured image. The algorithm analyzes the dark and light part of your finger, as well as ridges and valleys. To ensure effective capture of your fingerprint data by any in-display sensor, you have to exert a little bit of pressure on the screen so the sensor can accurately differentiate between ridges and valleys of each fingerprint.