Osram Infrared LED Oslux SFH4780S "One Eye Unlocks" Ends True

Mobile phones and tablets are increasingly used for sensitive applications such as online banking and online shopping, so the adoption of biometrics on these devices is the latest trend. In addition to fingerprint scanning, many manufacturers are considering iris scanning as a new biometric unlocking method. Infrared light will illuminate the eye, and the camera on the device will capture the iris image to identify its characteristics.

SFH 4780S from OSRAM Opto Semiconductors is currently the best performance ratio. With a wavelength of 810 nm, it is the first infrared light-emitting diode in a new high-performance Oslux package. Ms. Bianka Schnabel, Marketing Manager at Osram's headquarters in Germany, said: “OsluxLED has long been used in the visible lighting of mobile devices. Camera flash is one example. Now, we are expanding the range to infrared emitters.” Oslux The height of the component is extremely low and the emission angle is very narrow, thus providing optimum performance. This is achieved by a perfect match between the lens and the internal reflector. A feature of Oslux is that the surface of the component is very flat despite the use of a lens.

The SFH 4780S is small in size and has a very high radiation intensity. Although the height is only 2.4mm, the developers have successfully achieved an emission angle of only +-10 degrees. The result is that the typical radiant intensity of this IR LED has reached a record 2900mW/sr at 1A operating current. Such high light output is due to the high efficiency film chip with a side length of 750 μm. The chip uses the OSRAM nanostack technology to arrange two launch centers up and down inside. In pulse mode, the transmitter can even operate at currents up to 2A. In addition, because the SFH4780S is packaged in black, it can be integrated unobtrusively behind the cover of a mobile device.

Biometrics in mobile devices

For mobile applications, the lower the transmitter power, the better. This is very important.

In this respect, a wavelength of 810 nm is particularly suitable because it enables a variety of color, high contrast iris images with relatively low light levels.

For the well-known problem of insufficient space on mobile devices, OSRAM gave the answer to SFH 4780S. Current designs typically use multiple infrared LEDs, and the new IR LEDs are so bright that they require only a small transmitter to operate the iris scanner.

Applications where all eyes are exposed to infrared light must meet relevant eye safety standards, and iris scanners are no exception. This OSRAM provides designers with a special application note.