Fingerprint readers are becoming commonplace on smartphones ever since Apple integrated one into the iPhone. But including a fingerprint sensor requires manufacturers set aside an area of the case for it to sit, away from the touchscreen. Apple achieved this by integrating Touch ID with the home button while other manufacturers placed the reader on the back of their phones.
LG has now solved this problem completely by creating a fingerprint sensor that sits underneath the glass of a phone’s touchscreen.
Placing a sensor underneath glass while still allowing it to repeatedly collect accurate fingerprint readings required some precision engineering. LG managed to cut a shallow furrow into the back of the cover glass measuring just 0.3mm thick. The sensor sits inside this furrow ready to scan fingerprints on the other side of the glass.
By positioning the sensor underneath the glass it cannot be damaged by moisture or scratches. LG says it is as accurate as the more typical “button type” modules in use on smartphones today. The under-glass module has a 0.002% false acceptance rate. If you’re worried about the furrow making the glass weak, don’t be. LG claims it can still endure a large impact. For example, a 130 gram steel ball dropped 20cm on to the glass did no damage.
LG expects to have its sensor-glass combo being used in new smartphones within the next year, and is already in talks with several manufacturers. It seems likely we’ll see an under-glass fingerprint reader appearing in late 2016, and you can’t rule out Apple being the first customer for such a desirable new feature.