That means two Korean companies are going to launch phones in April, one with "Smart Pause" and the other with "Smart Video," that halts multimedia playback when a user's eyes are averted from the screen.
Both companies are claiming that their feature is a "revolutionary innovation."
The problem is that LG is also claiming that it filed for a patent for this technology in August 2009, according to a report by the Yonhap News Agency.
Samsung, for its part, denied that the Galaxy S4 infringes on LG's patent. The company said that it used original technology and different methods for its eye-tracking functionality.
Smart Video and Smart Pause aren't the only similarities between the Android-based Samsung Galaxy S4 and LG Optimus G Pro smartphones.
LG is introducing "the world's first Dual Camera function" the company announced hours before the Samsung Galaxy S4 unveiling.
The Galaxy S4 features its own Dual Camera with the identical picture-in-picture recording using its 13-megapixel rear camera and 2-megapixel front camera.
Samsung and LG didn't respond to TechRadar's request for a comment on whether or not there is a patent filed for the Dual Camera feature.
However, LG intends to review all potential patent infringements with the arrival of the Galaxy S4 release date next month, according to the Yonhap News Agency.
The good news for Samsung is that it may have a little bit of money freed up if LG ever decided to pursue the patent dispute, as a judge recently halved the billion-dollar Samsung vs. Apple lawsuit settlement.