Frequency Modulated Continuous Wave Optical Authentication System

Smart overview of the Invention

The authentication system utilizes a frequency modulated continuous wave lidar sensor (FMCW sensor) to gather structural information about a user's eye. This system sends a shaped frequency signal towards the eye and analyzes the reflected signal to obtain detailed information about the eye's structure and material properties. This data helps in identifying whether the eye belongs to a known user, thus facilitating user authentication for accessing devices or accounts.

Signal Processing

The received signal is converted into the frequency domain using a Fourier transform, highlighting peaks corresponding to different anatomical features of the eye, such as the eyelid, sclera, cornea, iris, lens, and retina. The peak heights indicate various material properties, which are crucial for identifying users based on unique biological attributes. The system can also detect biological indicators like heartbeat or breathing through these signal properties, ensuring the eye analyzed is indeed a living user's.

Authentication Mechanism

By comparing the structural information from the reflected signal with previously stored data, the system can authenticate the user. If the similarity score between the current and stored data exceeds a threshold, the user is recognized as a previous user. In the absence of a match, the system identifies the eye as belonging to a new user. This approach ensures secure and accurate authentication based on detailed eye analysis.

Additional Functionalities

The system can determine if the FMCW sensor is directed at an eye and whether the eye is open or closed. It uses three-dimensional volumetric data to ascertain the eye's presence and state, helping decide if the user is wearing a head-mounted device with the sensor. The system also detects eye movement through the Doppler effect, providing further insights into the user's identity and state.

Technical Components

The FMCW sensor, potentially an array of sensors, emits signals in invisible or near-invisible light frequencies, like infrared. A beam splitter may be included to compare emitted and reflected signals, aiding in time-of-flight calculations for distance measurement. This setup allows the system to filter out noise and focus on relevant signals, enhancing its ability to authenticate users accurately based on eye characteristics.