Future iPhones and iPads could move Apple's Touch ID fingerprint sensor from the device's home button to the display itself, allowing a more seamless and potentially dynamic way for a device to securely authenticate a user.
The possible future of Touch ID was revealed in a new patent application published on Thursday by the U.S. Patent and Trademark Office entitled "Fingerprint Sensor in an Electronic Device." Specifically, the filing describes how Apple might include a fingerprint sensor into the display stack on a device like an iPhone.
Apple's latest proposed invention related to a touchscreen Touch ID would allow the device to capture a single fingerprint at a pre-determined fixed location on the display. For example, an iPhone's lock screen or a third-party application could ask a user to place their finger in a specific spot on the screen in order to scan it and verify their identity.
Apple's system could also go even further, capturing a single fingerprint from any location on the display, or even scanning and identifying multiple fingerprints at once. By using the full space of an iPad, for example, Apple's advanced Touch ID system could enhance security by scanning all five of a user's fingerprints from one hand at the same time, or even a full palm print.
In the filing, Apple notes that fingerprint sensors embedded into displays in the past have degraded image quality on the screen by adding additional layers over the display. Such fingerprint scanning systems can also reduce the ability of the screen to sense traditional touch inputs.
Apple's proposed solution suggests that the fingerprint sensor for a display could be implemented as an integrated circuit connected to the bottom surface of a cover sheet, near the bottom surface, or connected to a top surface of the display. Apple also says that another method could place the fingerprint sensor as a full panel on the display.
In the filing, Apple notes that its full-panel fingerprint sensor could also serve as a touch sensing device, allowing the same technology to not only detect touch input, but also scan for fingerprints.
Apple's filing notes that its implementation could utilize "substantially transparent conductive material such as indium tin oxide" to address issues with display clarity on a full-screen fingerprint sensor.
Apple's interest in in-display fingerprint sensor technology is not new -- the company Apple acquired to create Touch ID in the iPhone and iPad, AuthenTec, has done extensive research on the subject. One such AuthenTec patent subsequently assigned to Apple was revealed in 2013, before the iPhone 5s introduced Touch ID to the world.
Both the 2013 patent and this week's newly unveiled filing are credited in part to Dale Setlak, co-founder of AuthenTec. Other inventors listed in the filing are Marduke Yosefpor, Jean-Marie Bussat, Benjamin B. Lyon, and Steven P. Hotelling.
Apple acquired AuthenTec in 2012, setting the stage for Touch ID, which in its current implementation is limited to the home button on the iPhone and iPad.