A new Samsung patent application is seeking to prevent screen burn in OLED displays. The system is geared towards OLED displays with in-display fingerprint sensors, and specifically those that use light to gather fingerprint information for authentication.
To that end, the patent describes a system with two printed circuit boards. The first sits underneath the glass screen, and has a built-in fingerprint sensor that picks up light reflected off of a fingerprint while it is in contact with the screen. The second circuit board, meanwhile, would be placed under the first, and would come with a processor that would automatically adjust the brightness of the pixels in the area of the screen around the fingerprint sensor.
The idea is that the phone would start at a lower brightness setting when the user first tries to unlock their device. If it is unable to make a positive match that first time around, the phone would then increase the brightness until it is able to confirm the identity of the owner. The dynamic system would theoretically minimize the amount of stress on the sensor and extend the longevity of the screen.
Screen burn occurs when an old image lingers on the screen even after the phone itself has moved on to display the next image. There is a greater risk of screen burn in high use areas of the phone, including the area around an in-display fingerprint sensor.
Samsung has featured in-display fingerprint recognition in several phones over the past few years, and the patent could eventually be applied to the flagship Galaxy series. However, Samsung is expected to provide the displays for Apple’s upcoming iPhone 12, which would provide the company with another outlet for the solution. Rumors have suggested that the iPhone 12 could mark the return of Touch ID, most likely with some kind of in-display technology.
Source: Patently Apple