Apple Touch ID might make an ultrasonic, in-display comeback

Apple can sing Face ID's praises all it wants but that's not going to chang the fact that there are cases where it is less convenient to use. Then again, even conventional fingerprint sensors, back or front, aren't always accessible at all times. One surface that's almost always accessible, no matter the angle (except face down), is the screen, which is why in-display fingerprint scanners seem to be the new holy grail of smartphones. A new report now claims that even Apple is still silently working on that but, in typical Apple fashion, will be doing things a bit differently.

The report from Korean media categorizes fingerprint sensors in three. Optical is the most widely used technology, both for normal sensors as well as the new in-display ones developed by Synaptics and used by Vivo. It basically shines light onto the fingerprint and compares the reflected light with the fingerprint image securely stored on the device. There's also a newer capacitive type that uses electrical patterns instead.

But even before the optical in-display sensors, Qualcomm was already working and demonstrating the third kind: ultrasonic sensors. As the name suggests, it uses ultrasound to map out even the most minute details of the skin. Because it neither relies on light or electricity, ultrasonic sensors can theoretically work even when the finger is wet or covered with substances like oil. It can also easily pass through glass, making it suitable for in-display use.

But while ultrasonic fingerprint sensors are claimed to be the most accurate of the three, they are also the most expensive and most difficult to make. This immediately rules out their use on a massive scale, leaving premium flagships and products as the most likely targets.

So far, only Qualcomm, Apple, and Samsung have been reported to be actively working on this technology. Given Apple's relationship with Qualcomm, however, it's most likely to be developing an ultrasonic sensor on its own. Coincidentally, Samsung is also reported to be doing the same but less because of its business relations with Qualcomm and more because it intends on using the technology across a wide range of its products.