Touch ID May Be Replaced by Acoustic Imaging Technology in ‘iPhone 8’

Rumours strongly suggest that Apple will replace the Touch ID home button with alternative bio-recognition hardware when it launches an OLED version ‘iPhone 8’ later this year. Although the technology enabling that transition is not yet known, a new Apple patent application published today by the US Patent and Trademark Office (USPTO) indicates just how the company might achieve that (via AppleInsider).

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Titled “Acoustic imaging system architecture”, the filing details a method by which a conventional capacitive fingerprint sensor like Touch ID might be replaced by an array of acoustic transducers laid out beneath a device display or its protective housing. Apple’s acoustic imaging system can be configured to read a user’s fingerprint.

According to the filing, ridges in a finger pad introduce an acoustic impedance mismatch that causes the mechanical waves generated by a transducer to reflect or diffract in a known manner. 

Like other biometric security solutions, the digital maps obtained by an acoustic imaging system are ultimately compared against a database of known assets to authenticate a user. 

Thanks to its design, the acoustic system can be installed practically anywhere in a device chassis, including directly under a display. Other potential points of integration include a screen’s perimeter or bezel, around buttons and in non-input areas of a housing, like a rear chassis. The latter coupling method would allow an example system to sample a user’s entire handprint.

Apple’s acoustic imaging patent application was first filed for in August 2016.