Fingerprint readers are increasingly ubiquitous in smartphone design, so much so that the question is not whether to include one, but where to put it. Where some manufacturers have chosen to add readers into buttons on the front or raised sections on the back of their devices, LG Innotek has a new idea — put it under the phone's screen. The LG affiliate announced today that it had developed a new fingerprint sensor that it has slotted into a tiny 0.01-inch (0.03 milimeter) space cut into the underside of smartphone cover glass, allowing device designers to incorporate fingerprint readers without dedicated buttons, pads, or other exposed elements.
LG says fingerprint recognition rates on the under-glass module are comparable to button-type sensors and should reduce any smartphone malfunctions, with the added bonus of allowing phones to be made waterproof or scratch-resistant, or simply designed to look sleeker. The company it hasn't yet announced whether it will be using this new module in any upcoming phones, but an LG spokesperson told the Korea Times that the company is currently in talks with some smartphone manufacturers to commercialize the new sensors "within the year."
http://www.theverge.com/circuitbreaker/2016/5/1/11553830/lg-fingerprint-sensor-under-glass-screen