Samsung is reportedly working on an under-display sensor for unlocking its foldables, but the company's decided that it's better off keeping the fingerprint-sensing power buttons on its rumored fourth-gen foldables for ease of use. Instead, we may see the new sensors debut on the Galaxy Z Fold 5 and Z Flip 5.
Normally I'd be disappointed that a phone wasn't getting an exciting-sounding upgrade like this, especially as the under-display fingerprint scanner on the Galaxy S22 range is so fast and responsive. But I think side-mounted fingerprint sensors are always going to make more sense than under-display ones for foldables.
They're more accessible because they stay in the same place whether the phone's folded or unfolded, and are sat within easy reach of your thumb or index finger, meaning you don't have to do an awkward stretch with one hand or use your other hand to get your fingerprint in the right spot.
There has been a Samsung patent that details a two-sided fingerprint sensor on a foldable device. The sensor is centrally aligned on the cover screen, but can also be accessed on the left side of the inner display when opened. While it still means you probably have to register extra fingerprints to make it work in both folded and unfolded modes, it's still probably the best option Samsung could go for right now.
As BusinessKorea's report says, we should see the Galaxy Z Fold 4 or Z Flip 4 debut around Q3 of this year, as the last generation did in 2021. Rumors we have heard so far for the Z Fold 4 include that it could get the same telephoto camera as the Galaxy S22, as well as a new hinge design and tougher display to work with the rumored built-in S Pen.
Leaks for the Z Flip 4 have been much thinner on the ground, so it remains the more mysterious of the two devices. Also, we may see the "Z" part of both phones' names disappear entirely, given the unfortunate resemblance to a symbol used by the Russian army invading Ukraine.