A newly-published patent application indicates Apple is working on refining its as yet unreleased under-display fingerprinting scanner technology, which could be used in the iPhone maker’s much-rumored return to using Touch ID on the iPhone.
The patent application was first spotted by Patently Apple and filed with the United States Patent and Trademark Office, is titled “Under-display fingerprint sensing based on off-axis angular light” and explains how an under-display fingerprint scanner can be made more accurate and reliable.
Patently Apple says the display consists of active red-green-blue (RGB) pixels that emit light and illuminate the finger placed on top of the display. The light reflected from the finger passes through the openings between the display pixels and is captured by the sensor beneath the display.
The contact and non-contact regions between the finger skin and the display’s glass plate generate different light intensity, which thus forms the ridge-valley contrast of the fingerprint. Due to the low-light throughput and diffraction caused by the display stack, the fingerprint image may suffer from low contrast and low signal-to-noise ratio (SNR).
However, Apple’s system is designed to provide a method to capture the off-axis angular light from the finger by insertion of angle-dependent filtering options between the display and the sensor. This method could improve the contrast of fingerprint impressions and maintain the compactness of the entire sensing system.
Examples in the patent notes focus on an OLED display being used on the iPhone, that display system is currently being used in the entire iPhone 12 lineup.
Barclays analyst Andrew Gardiner and three of his colleagues on March 12 said Apple’s upcoming “iPhone 13” handsets will “likely” feature a fingerprint scanner embedded under the display for device authentication in addition to Face ID.
Numerous other rumors have floated about Apple’s bringing the fingerprint scanner under the display. Industry analyst Ming-Chi Kuo, Bloomberg’s Mark Gurman, and The Wall Street Journal’s Joanna Stern have claimed Apple is working on an under-display fingerprint scanner for the iPhone 13.
