Apple Patent Reveals Touch ID Fingerprint Sensor Tech That Works Through Display

When Apple launched the iPhone 7 and iPhone 7 Plus last month, it took away the physical Home button, instead leaving behind a fixed panel with haptic feedback to simulate a button press. Future iPhones may ditch this vestigial Home button altogether (and with it, traditional Touch ID) to allow for a more advanced way to read your fingerprint.

According to a new Apple patent, the company is working on a way to read your fingerprint through a mobile device’s display. Apple has taken plenty of flak over the years for the huge bezels on its smartphones, and the company acknowledges in the patent that integrated Touch ID into the display, "not the least of which is an interest in avoiding assigning valuable surface space exclusively to an component that may only be used briefly during the process of identifying the user."

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However, embedding Touch ID into the display poses its own set of challenges, as there is a more significant gap between the hardware used to read your fingerprint and where your finger actually rests on the display (at least compared to current Touch ID implementations). “Such separations may lead to blurring of the electric field and a corresponding loss of resolution of the fingerprint images detected by the capacitive sensor,” writes Apple in the patent filing.

To combat this, Apple uses patterned conductive layers, or electrostatic lenses, to shape the electric field associated with the operator’s finger. It effectively “bridges the gap” between the actual screen glass and the sensor, allowing for accurate scans of your fingerprint.

Given that the rumor mill for next year’s iPhone 8 began the minute the iPhone 7 and iPhone 7 Plus were unveiled in September, this “Touch ID through the display” technology seems like another bullet point that we can add to the list. The question is how exactly will Apple implement such technology. Will there be a small zone on the display where all Touch ID operations must take place, or will the entire display be available for scans? And if the Home button is completely taken away, how do we get “Home”?

These questions and more will likely be revealed over the next year as speculation and rumors ramp up for the iPhone’s 10th anniversary.