More and more applications are using invisible infrared (IR) light sources with high optical output power levels in the range of Watts. This paper focuses on the benefits using high power infrared products and their special requirements in the application.
In general high power emitters can be driven with DC currents in the range of 1 Ampere whereas most low power products like 5 mm Radials are limited to 100 mA. As the light output increases with driving current the optical power is raised by a factor of ten compared to standard devices.
At the same time much less board space is occupied as fewer devices are needed. On the other hand a careful thermal management is absolutely mandatory because the thermal power dissipation is increasing in the same way as the optical output power. To keep the junction temperature of the chip as low as possible a low thermal resistance is needed and the standard FR4-PCB has to be replaced by a metal core PCB. Like this a high optical efficiency of the IRED can be achieved.
High power emitters as infrared light sources are used in: Consumer / Industrial: - Closed-circuit television (CCTV) - Biometric access control systems - Machine vision systems - Automatic number plate recognition (ANPR) - Camera based distance systems - 3D-cameras (gesture recognition, play tables) - 3DTV (data transmission to shutter glasses) Automotive: - Night Vision - Sensing systems (pre-crash) - Driver monitoring