Smartphone 3D Imaging Lives on in the iPhone 15

December 22, 2023

Cost efficiency and maximizing display area drive innovations in the Face ID and LiDAR modules

The years 2016 to 2019 witnessed an explosion in smartphone 3D imaging, with our team confirming that over 20 smartphones incorporated such technologies. Apple made notable contributions, introducing the front-facing Face ID system in 2017 and subsequently launching the rear-facing LiDAR (Light Detection and Ranging) module in 2019. However, by 2023, most OEMs had shifted away from this direction. Front-facing facial recognition systems were generally perceived as not justifying the loss in display area, while expensive rear-facing 3D imaging was superseded by more cost-effective multizone rangers optimized for laser autofocus. Nevertheless, Apple remained steadfast in this domain. The leading consumer 3D imaging companies by revenue predominantly comprise entities within the iPhone supply chain. Thanks to these collaborations, the iPhone not only retains its 3D imaging capabilities but also consistently introduces innovative advancements in these modules.

The Face ID system has undergone significant evolution since its inception to minimize the notch size on the display. With the iPhone 13, Apple integrated the entire system into a singular module, resulting in a 33% reduction in the notch size. Subsequently, the iPhone 14 Pro further refined this, transitioning to a 21 mm pill-shaped “Dynamic Island.” This was achieved by leveraging a groundbreaking, albeit costly, SWIR-based under-display proximity sensor from Coherent, rendering the notch unnecessary for operation. Moving forward with the iPhone 15, Apple collaborated with STMicroelectronics and Trumpf to incorporate the proximity sensor directly into the Face ID module without altering the baseline, thereby maintaining the Dynamic Island’s dimensions at a reduced cost.

The iPhone 15 Pro model also boasts a revamped LiDAR module centered around a direct time-of-flight (dToF) solution developed by Sony. The bottom-emitting VCSEL (Vertical-Cavity Surface-Emitting Laser) light source is seamlessly integrated with the driver ASIC, generating an 8×14 point dot pattern via over 100 independently controlled mesas. Each point’s dToF is subsequently gauged by a 940 nm-enhanced SPAD (Single-Photon Avalanche Diode) image sensor equipped with onboard distance calculation logic. This redesign diminishes the active die area by more than a third and eliminates diffractive optics, resulting in considerable cost efficiencies compared to its predecessor.

Through these pioneering developments, Apple has addressed the primary concerns associated with 3D imaging that dissuaded Android OEMs: the display area compromise for front-facing systems and the cost implications for rear-facing implementations. Such endeavors underscore Apple’s unwavering dedication to advancing these technologies.

Yole Group has multiple products covering the evolution of Apple’s technology, from market and technology analyses to reverse engineering of the most popular Apple’s devices.