Samsung has filed a patent for the integration of the fingerprint reading on the whole display of a telephone.
Currently it is possible to have the fingerprint detected directly on the screen, but only in a fixed and well-defined part. With this invention, however, the whole display can become a fingerprint reader. These are some concepts of the idea:

Patent drawings of Samsung's all-display fingerprint reader Patent drawings of Samsung's all-display fingerprint reader

The convenience of this feature can be exploited to facilitate user authentication even in the new generation of folding smartphones, as well as in tablets and other devices.

At a technical level, the new reader will be supported by a low-power processor that will only wait for the user's touch. The reader will scan the finger three times; each scan will require between 20 and 30 ms. Adjusting the screen brightness between one scan and the next will require 200 ms. In total, they will serve roughly 700 ms to complete a scan from start to finish, thus respecting the standards of Synaptics optical readers.