Apple appears to be using optical biometric fingerprint scanning technology for the under-display version of its Touch ID, according to patent information reported by Patently Apple.

A patent application published by the U.S. Patent and Trademark Office describes a “display stack” for a system scanning a fingerprint from static placement or a swiping motion across the sensor area. The optical imaging arrays can include single or multi-element imaging sensors, and can be used for imaging, sensing, proximity sensing, depth sensing, receiving structured light, optical communication, or biometric imaging, the application says.

In addition to possible implementation in iPhone models, the application also depicts a MacBook incorporating the technology.