The iPhone 13 may be the first flagship iPhone to feature an in-display Touch ID sensor, if Apple can turn its newly acquired patent into an actual product by launch.

The "Through-Display Optical Transmission, Reception, or Sensing Through Micro-Optic Elements" patent, discovered by AppleInsider, shows Apple's fingerprint scanner into its mobile phones.

In-display fingerprint scanners are a common sight on mid-range and flagship Android phones, but Apple has been using Face ID since 2017, when it moved away from the Touch ID design of the home button on the iPhone X. It then reappeared in the iPhone SE (2020), but we have yet to see this system return in the main iPhone release.

There are significant engineering challenges to overcome when designing such a system. The most significant of these is ensuring that enough light can be transmitted through the display and other components to the sensors in the phone. Apple's patent details how this can be overcome through components that are translucent to certain types of light and apertures that direct light around opaque components or onto the sensor itself (see below).

A second patent titled "Optical Fingerprint Detection System" was also spotted by AppleInsider. This one is not a complete component design, but a solution to a common problem: phones with OLED displays and in-display fingerprint scanners sometimes have trouble reading fingerprints at low temperatures because the pixels in the display react to low temperatures. The patent therefore suggests various software solutions to the problem, indicating that Apple is seriously considering Touch ID for sub-displays.

There have also been rumors in the past that Apple is working on a side-mounted fingerprint scanner. Like phones like Samsung's Galaxy S10e and Huawei's Nova 5T, this rumor suggests that it will be added to the iPhone SE Plus, which will accompany the existing iPhone SE (2020) as Apple's larger budget phone.

So far, there are no rumors that the iPhone 12 will adopt Touch ID and instead inherit Face ID from the iPhone 11 series; Apple analyst Ming-Chi Kuo has a good grasp of Apple's next move, and he believes the 2021 He previously stated that in-display Touch ID will join Face ID on the iPhone in 2021.