Apple Reportedly Solves Under-Display Face ID, Moving the iPhone 18 Pro Towards an “All-Glass” Design

October 1 (IT Home) — The technology outlet 9to5Mac published a post yesterday (September 30) reporting that on the iPhone 18 Pro and iPhone 18 Pro Max, Apple will embed the Face ID module beneath the screen — a key step towards Apple’s vision of an “all-glass” iPhone design.

For users, when using the iPhone 18 Pro or iPhone 18 Pro Max in daily life — looking at it from near or far, taking photos, or even shooting macro images — the sensors hidden under the screen are imperceptible. Only under a microscope can the difference in pixel arrangement be seen.

On the technical side, the outlet sums up the approach in three parts: making way for infrared light, compensating for the difference with brightness, and hiding the seams with a filter.

Face ID relies on emitting and receiving infrared light to recognise a face, but ordinary screen pixels are packed so tightly that infrared light cannot pass through. Apple’s engineers redesigned the pixel layout, deliberately enlarging the gaps between pixels in the area of the screen directly above the TrueDepth module.

These “gaps” are normally invisible to the human eye, but infrared light can pass through them to carry out the emitting and receiving tasks. The pixel density in that area is reduced by 50% — the equivalent of changing a row of 10 bricks into 5, leaving space for infrared light to get through.

Halving the pixel density creates a problem: that area may look darker, like a patch on the screen. Apple therefore uses a local brightening solution, raising the backlight or pixel brightness in that region through the driver chip so that the brightness the human eye perceives matches the surroundings.

Even with larger pixel gaps and increased brightness, there is another risk: visible light could also leak out through the gaps, making the screen’s colours or contrast abnormal. Apple integrates a layer of infrared filter inside the screen, working like a “one-way door” that lets infrared light through while blocking visible light from leaking out.

IT Home notes: the “all-glass” idea is the ultimate iPhone design vision put forward by Apple’s former chief design officer, Jony Ive: a future iPhone should be made from a single piece of glass with no openings or seams, with every sensor, camera and speaker hidden beneath the glass, so that all the user sees is a pure, continuous glass surface.

This idea can be traced back to the early design discussions of the iPhone. Ive believed that any opening, bezel or physical button was a violation of the “pure form.” Ideally, an iPhone should look like a device that has “grown” out of a single piece of glass, with no artificial cuts or functional openings.