Safety in focus: infrared LED for iris scanners protects against intruders

New Oslux IRED ensures even illumination, simplifying identification of unique iris patterns

Osram Opto Semiconductors is set to present a new infrared LED (IRED) for iris scanners at the upcoming Mobile World Congress. The SFH 4787S illuminates the eyes so evenly that the software identifying the iris pattern now hardly needs to correct artefacts. Like its predecessor, its direction of emission is slightly angled rather than vertical, thus simplifying the design process by eliminating the usual mechanical aids. 

Iris recognition is among the most reliable biometric identification methods. In brief, iris scanners illuminate the eyes with infrared light and a camera takes a photograph. Special software then uses this to detect the iris pattern, which is unique to each individual.

Osram Opto Semiconductors is a technology leader in this field. Two years ago, the company was first to market an infrared LED that brought this technology to smartphones and other mobile devices. This was followed by a version with a slightly angled direction of emission, which meant that designers no longer need mechanical aids to tilt the entire LED. The angle of emission aligns with the camera’s field of view.

Even illumination simplifies processing
This third-generation Osram IRED for iris recognition meets another need in this application: the brightness differences in the camera images should ideally only originate from the iris pattern and not be additionally caused by a gradient in the illumination. This would mean that the software needs to correct fewer artefacts when determining the iris pattern. With the SFH 4787S, Osram has thus developed an emitter with a flat light, optimizing the reflector and lens to ensure virtually constant intensity across the emitted light beam. 

Apart from this, the SFH 4787S is almost identical to its predecessor, the SFH 4786S. Both are based on the compact
3.5 x 3.5 x 1.6 millimeter large Oslux package. A wavelength of 810 nanometers (nm) delivers high-contrast images for all eye colors. The emission direction is tilted by 8°, while the emission angle is ±18°. The optical output of this highly efficient emitter is 720 milliwatts (mW) at a current of 1 amp, with a radiant intensity of 1,000 milliwatts per steradian (mW/sr).

Industrial applications gaining ground
The impetus to develop more compact and reliable iris scanners was driven by the need for dependable solutions to safeguard mobile devices from unauthorized access. Gradually, the technology is now making its way into other sectors. “Access control as a whole is becoming increasingly important and iris recognition remains one of the most reliable methods here,” explains Bianka Schnabel, Marketing Manager at Osram Opto Semiconductors. “Following in the footsteps of consumer markets, we are now also seeing an upswing in interest from various industries.”