Eye tracking systems illuminate the user’s eyes with infrared light, register the reflections with an IR-sensitive camera sensor, and use dedicated algorithms to determine the user’s direction of gaze and eye movements. Japanese startup Fove are now offering a virtual reality headset with eye–tracking as a novel means of interaction. It uses tiny IREDs (Infrared Emitting Diodes) developed by Osram to provide the infrared illumination to track the wearer’s direction of gaze and eye movements.
Fove say they have developed a “sophisticated reality system that allows wearers to immerse themselves in another world, with enclosed headsets shutting them off from their real surroundings.” To provide an authentic virtual experience, the sensors need to keep track of users’ actions and positions and integrate these with their location and movements into the virtual realm.
The technology allows for “foveated rendering”, a new approach that significantly reduces demand on both computing power and graphic cards. Based on the information about the user’s point of gaze, VR systems can adjust the resolution and render areas in the direct field of vision in high resolution while allowing for lower resolution in the periphery.
To design this function into a headset, several IREDs are mounted around the two lenses. Fove are using SFH 4053 ChipLEDs from Osram, which measure only 0.5 mm × 1.0 mm × 0.45 mm. Their emission wavelength of 850 nm matches the spectral sensitivity of the camera sensor, and their beam angle of ±70° ensures even illumination of the user’s eyes.
Fove also use infrared sensor technology to track a user’s position and movements in order to integrate these into the VR action. Several Osram SFH 4253 TopLEDs are mounted around the headset to create a pattern of IR light dots, which are registered and tracked by a camera to determine the user’s movements.
