Samsung seeks a patent protecting its dual-sided, under-display fingerprint sensor for the Fold 4 5G

With the Samsung Galaxy Z Fold 3, there was some thought given to equipping the device with an under-display fingerprint scanner. That didn't occur and instead, Samsung integrated its fingerprint scanner with the power button on the side of the device. However, according to LetsGo Digital, Samsung did submit on March 31st a patent applicationtitled "'Foldable electronic device capable of detecting fingerprint through at least part of the display'"

The application was made through the World Intellectual Property Organization (WIPO) and was published by the organization just a few days ago. The filing explains what is the issue here; the flexible screen on a foldable device is more apt to show creases when pressure is applied to the display. This makes it harder for fingerprints to be read using an under-display fingerprint scanner on a foldable phone.

Samsung has created a solution as laid out in the patent filing. The answer is to have the fingerprint sensor placed on the device in such a manner that it will be used to verify the fingerprints of someone using the external cover screen and verify the prints of someone using the tablet-sized display when the foldable phone is fully open. The answer from Samsung is to use a double-sided fingerprint scanner.

This works by placing the fingerprint scanner into the lower left of the foldable display. This will allow biometric authentication to take place with the display closed or open. Between the two sensors, a small printed circuit board is placed which connects to the main circuit board.

The original filing was made back in 2020 in South Korea. By the time the Galaxy Z Fold 4 is released next year, Samsung might be ready to include in-display fingerprint scanners with its foldable devices.

While Samsung has the global lead in foldables at the moment, it hopes to continue to bring pricing down to bring these products within reach of more consumers. And pricing becomes more important as other manufacturers release their own foldables. Firms like Google (whose Pixel Fold could be announced soon), Xiaomi, Vivo, and Oppo could put the pressure on Samsung although ironically, many of these companies will source their foldable displays from Samsung.