Reports that Galaxy Note 9 will come with an on-screen fingerprint sensor have recently become contradictory. The new information says that Samsung has given up this functionality to include Galaxy Note 9, leaving the function to the Galaxy S10. Samsung will not be the first company to use this technology, but the technology that Samsung will use will be superior to that offered by Chinese manufacturers.
The under-screen fingerprint sensors work with an optical sensor that displays the fingerprints reflected on the bottom of the screen. Although the production of this technology is not difficult, it does not work very well. Samsung is developing an ultrasonic fingerprint sensor that will work much more accurately.
This sensor sends an ultrasonic wave to the finger. Some of this dive goes back to the sensor. The returned information is based on the fingerprint indentation, and a very accurate 3D map of the fingerprint can be removed.
It's too early to talk about the Galaxy S10 yet, but some of the claims say the phone will be available at CES 2019 in January. According to this claim, Samsung's foldable phone will be introduced at MWC 2019.