After turning on Accidental touch protection, you may notice a small pixel-sized light flashing on the top of your phone in the dark. When you touch the screen while the Accidental touch protection function is activated and Always-on display is preset to 'Tap to show', such small light flicker will appear.
That is because the proximity sensor is operated due to Accidental touch protection, and it is not a product defect. Some models that have proximity sensor behind the display panel, the sensor is turned on to determine whether it is in a pocket when the screen is turned on in low light (10 lux or less). When the proximity sensor is operated, the phenomenon of light flickering is recognized by the photoelectric effect. In other words, light flashing is the operation of the sensor to prevent malfunction. The brighter you set your screen, the brighter the flashing light will be.
The models that the proximity sensor is located behind the display panel are as below.
- Galaxy A91, Galaxy A90 5G, Galaxy Note10 Series, Galaxy S20 Series, Galaxy Z Flip