Answer: Jan. 24.
At CES in Las Vegas earlier this month, Chinese mobile phone manufacturer Vivo revealed a prototype for a smartphone with a fingerprint sensor built into the screen itself. Currently, fingerprint sensors have been limited to the bezels on smartphones, such as in the iPhone’s home button.
Vivo recently confirmed a Jan. 24 event to officially reveal the previously unnamed device. Called the X20 Plus UD, the phone will likely be very similar to the X20 Plus, which Vivo announced in October 2017. That device has a Qualcomm Snapdragon 660 processor, 4 GB of RAM, a 12-megapixel dual-lens camera and a 6.4-inch screen.
According to Digital Trends, the prototype X20 Plus UD at CES was an almost entirely bezel-less version of the X20 Plus, with the first in-screen fingerprint sensor. The sensor itself, called Clear ID, was built by Synaptics, a sensor company that revealed the design at the end of 2017. For now, the X20 Plus UD will probably only be available in China, but as the tech becomes more mainstream it will likely spread to other countries.