Apple has been granted a patent (number 9,570,002) for an “interactive display panel with IR diodes,” which shows that Apple has looked into iPhone and iPad screens with built-in Touch ID without the need for a dedicated button. Such a feature has been rumored for inclusion in the “iPhone 8,” which is expected to arrive this fall.
Here’s Apple’s summary of the invention (which is heavy in tech-speak): “Exemplary methods and systems use a micro light emitting diode (LED) in an active matrix display to emit light and a sensing IR diode to sense light. A display panel includes a display substrate having a display region, an array of subpixel circuits, and an array of selection devices. Each subpixel circuit includes a driving circuit to operate a corresponding infrared (IR) emitting LED in a light emission mode. Each selection device may be coupled to a corresponding sensing IR diode to operate the corresponding sensing IR diode in a light sensing mode.”
As noted by AppleInsider, the patent was originally assigned to LuxVue, a company Apple purchases in May 2015. LuxVue is a micro LED developer.
Of course, Apple files for — and is granted — lots of patents by the U.S. Patent & Trademark Office. Many are for inventions that never see the light of day. However, you never can tell which ones will materialize in a real product.