A transmitter has been released by Osram Opto Semiconductors, based on the company’s proven Firefly platform, used widely for LEDs in the visible spectrum. The SFH 4055 transmitter, Osram’s smallest side-looking infrared LED to date, has a wavelength of 850nm and is primarily targeted at eye-tracking systems in augmented and virtual reality headsets. Eye-tracking systems use multiple infrared LEDs to illuminate users’ eyes and capture the light reflected back with camera sensors.
This allows these systems to compute the position of the user’s pupil and determine what direction the user is looking in. The technology also allows for the incorporation of foveated rendering, whereby the rendering workload of the processor is greatly eased by reducing the image quality in the peripheral vision.
Incorporating this technology into virtual reality (VR) or augmented reality (AR) headsets calls for extremely compact infrared LEDs, tiny enough to fit into glasses around eyepieces. With a footprint of 1.0x0.325x0.55mm, the new Firefly fits the bill.
Intuitive interaction, less computing power required
Eye tracking supports entirely new, highly intuitive forms of interaction in VR and AR applications and enables users to control software programmes by directing their gaze. For instance, AR glasses can display information that relates specifically to an object a user has selected.
There is an added benefit for VR systems: They can exploit eye tracking to reduce the amount of computing power they require – a useful capability given the need to render images quickly to provide users with a realistic experience. Image rendering calls for computers that can deliver a lot of processing and graphics power. With eye tracking, these systems can focus on rendering images at a high resolution in the line of sight and maintain a lower resolution in the periphery.
Benefits for optical touchscreens, too
The SFH 4055 is generally aimed at applications that require compact infrared transmitters. Optical touchscreens, for instance, rely on very low-profile, side-emitting infrared LEDs to create a grid of infrared light used for detecting finger positions.
Infrared transmitters, lasers and photodetectors from Osram are already in use in VR and AR solutions, and the company’s first infrared Firefly will enable it to support new use applications in this fast-growing market.