The Korean Android OEM filed a patent with the Korean Intellectual Property Office (KIPO) on March 15, 2019 with 14 drawings onboard. The patent was approved on April 20, 2019. In it, we see a smartphone with a hole at the top middle of the display.
The new punch-hole display shows three punch holes, one for the selfie camera. The other two punch holes are unknown, though there could be two selfie cameras and a microphone sensor LG has in mind. One of the three sensors on the front of the upcoming full-screen smartphone could pertain to a Face Unlock feature or iris scanning for that matter.
The notch bar was a design trend started by Essential, popularized by Apple, and, as with many Apple implementations, it hasn't taken long before Android OEMs decided to follow. But when Android OEMs adopted the notch design trend, they started to customize it in different ways (expected for Android users).
The notch bar led to "waterdrop" notch design where the shape of the notch is a waterdrop. Some went with the waterdrop notch, though others stuck to the notch bar to remain safe with smartphone design.
Samsung and Huawei, however, didn't want to stay complacent with notch design, so they went all out — revealing punch-hole displays at the end of 2018. Samsung first implemented its punch-hole design with the Galaxy A8s at the end of 2018. Huawei previewed the Honor View 20 with its first-ever punch-hole display, though it didn't go on sale until earlier this year.
Punch-hole displays are designed to keep the display compartment for selfie cameras, microphones, and other sensors as small as possible while pushing the display to expand across the front of the phone as much as possible.
The punch-hole display creates an in-display camera where nothing stops the smartphone screen from going as far across the phone as it wants to. This push toward full-screen phones has moved manufacturers to find new ways to implement the same features it always has while doing so in a way that respects the bezel-less idea.
LG's implementation of the punch-hole display follows Samsung and Huawei in that it's the first smartphone where LG has placed its selfie camera and sensors under the display rather than above the display (with a bezel, of course).
The "punch-hole display" is so named because the hole in the display for cameras and other sensors looks like someone "punched" a hole in it (hence the name). As much as cameras are "under the display," they're not able to be fully submerged without punching holes in displays because camera quality suffers when cameras are fully submerged under the display.
Optical fingerprint sensors work well, but photography suffers with fully-submerged cameras. The punch-hole scenario places cameras in the displays but keeps the cameras "open" so as to not interfere with images and smartphone photography.
Some say that punch-hole displays for cameras and sensors are a much nicer design than waterdrop notches and notch bars, but others don't want anything but a nice, clean display, hole-free and notch-free. Until Android OEMs can figure out how to maintain flagship photography with fully-submerged in-display cameras, punch-hole displays are here to stay.
The punch-hole display design, started by Samsung and Huawei, can now be seen in Android-powered smartphones such as the Galaxy A8s, Huawei's Honor View 20, the Huawei Nova 4, Lenovo Z5s, the upcoming Samsung Galaxy A90 5G, and Samsung's flagship Galaxy S10 and Galaxy S10 Plus. The Galaxy Note 10, to be announced August 7th, 2019, will join the ranks.