The reason is partially because of Apple's need to keep that great big home button situated beneath the screen for Touch ID fingerprint authentication. Soon, however, Apple might be able to ditch the home button without having to move its fingerprint scanner to a less convenient position on the back of the phone.
Apple has been working for a long time to figure out how it can embed its Touch ID fingerprint scanner under the iPhone's display so that it can give its iPhone lineup a smaller overall footprint without having to shrink screen size. Touch ID isn't going anywhere anytime soon, of course, but Apple has been hard at work trying to revamp it now that it sells larger iPhones.
The good news is that a next-generation fingerprint scanner cable being positioned beneath a smartphone's display has officially been unveiled. The bad news, however, is that Apple isn't the company that unveiled it.
LG Innotek last 2 May showed off the first under glass fingerprint sensor module from a major manufacturer. Using this technology, a smartphone or tablet can employ fingerprint authentication without the need for a separate sensor mounted beneath the display, or on the back or side of the phone.
How did LG pull it off?
"LG Innotek cut a shallow furrow of 0.01 inches (0.3mm) thick on the lower backside of the cover glass and installed the fingerprint sensor inside of it with using their supreme precision and combination technology," the company said in its announcement. "With this module, the sensor is not exposed to the outside of the device, so manufacturer can produce a sleek designed smartphone. Fingerprint recognition area also can be indicated by various patterns up to design of complete product."
The release continued, "High-strength cover glass protects the sensor and prevents it from coming in direct contact with water or damage from scratches. At the same time, the new module secured the fingerprint recognition accuracy compared to the button type. The new module has a false acceptance rate (FAR) of 0.002 percent."