Apple is developing a new optical fingerprint sensor for future iPhones, re-introducing Touch ID.
According to a new patent filed by Apple, the company is developing an optical fingerprint sensor that uses light to shine and scan a fingerprint. Even though optical sensors are worse than ultrasonic ones — which reads ultrasonic vibrations from the finger —.
In the patent, Apple is saying that by capturing off-axis angular light, the sensor will:
“Improve the contrast of fingerprint impressions and maintain the compactness of the entire sensing system. For certain objects, oblique light forms stronger imaging signals than light that is normal to the imaging plane. For example, a fingerprint-sensing system/device with multidirectional illumination, such as an under-display fingerprint-sensing device may utilize oblique angular filters to capture the stronger signals to enhance image contrast.”
Also in the patent, the pixels of the screen emit light, which illuminate the finger when it is touching the display. Light travels back when it is reflected by the finger to the under-display sensor using ff-axis angular light.
All of this creates a fingerprint sensor that works under the display with great response and reliability, without taking much space inside the device.
It is expected that the next iPhone 13 or 12s will have a smaller notch, a faster processor, a better 5G connectivity, and the return of Touch ID. But with Apple filing patents to test the sensors its developing, it could take much longer for Touch ID to come back to iPhones.