Application Note 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 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 metal core PCB. Like this a high optical efficiency of the IRED can be achieved. High power emitters as infrared light sources Closed-circuit television (CCTV) Biometrie access control systems Machine vision systems Automatic number plate recognition Camera based distance systems play tables) 3DTV (data transmission to shutter Night Vision Sensing systems (pre-crash) Driver monitoring Ptjllnum Diagcn OSTAR Lighting High power product overview. In Figure 1 the OSRAM IR high power product portfolio is presented. A product selection guide with the main optical parameters is shown in Table 1 (see In general two common wavelengths spectral emission range matches well to the sensitivity range of standard photo diodes, photo transistors or CCD and CMOS cameras with extended IR sensitivity. The available Diamond Dragons with integrated ±20° silicone lens provide a narrower beam compared to the Platinum Dragons with ±60°. The focussed beam allows an irradiation of objects at higher distances. The OSLON is in between with For applications where space is very limited the 850 nm double stacked emitters vertically stacked pn-junctions are used in one chip, are the right choice. These devices Opto Semiconductors

provide about twice the light density per current and this decreases the number of devices needed to get the same optical performance. As these devices are operated at a higher voltage with the same thermal properties, the increased power dissipation Multi-chip emitter arrays as the OSRAM OSTAR Lighting (3x2 chip matrix) or OSRAM OSTAR Observation (5x2 chip matrix, see separate application note) provide the highest possible packing density for the light output as the chips are assembled as close as possible. Especially in this case an effective cooling is absolutely 5mm Radiais Powertopled Dragon...

When choosing an additional IR light source for a camera system one has to be aware of several parameters that affect the amount of light hitting the camera chip. In Figure 3 the main parameters are visualized and the question arises, which is the right emitter and how many emitters are required to get a good quality picture of the irradiated First of all the object size, its distance to the camera and the desired picture resolution determine the optical properties of the camera system (sensor size, objective) and Typical distances for some applications are: Examples: door admission, machine...

- F-Number of optics f/# (f/# = f/D, with D= diameter of entrance aperture) transmission of optics Toptics pixel size to calculate the minimum detectable object feature size r Radiant intensity le of the source Emission wavelength Irradiance at the object position (valid for far Radiance of the object (considering object is Irradiance at the sensor position [3]: Resolved object feature size: Each camera system can be optimized by choosing the right parameter settings (e.g. frame rate, integration time, etc.). As there are many different systems available it is not the scope of this application...

Choose an emitter with a radiation characteristic that fits to the scenery and the field of view (FOV) of the camera system. The field of view calculation of the camera system can be done by using equation (1) and the given camera parameters: The result is ±11.3° in horizontal direction and ±8.5° in vertical direction. This corresponds to a horizontal maximum object size of 3 m and a maximum vertical object intended a person can be mapped in full height using this setup. can see that the radiation characteristics of requirements. The one which comes close is characteristic of ±20°. Much of the...

system). If N components are used in the system that are thermally independent from each other, this can be described by a parallel connection of the N connected in series to the of the heat sink: For more details please see application note "Thermal Management of Golden DRAGON The temperature increase from junction to ambient can be calculated by using the thermal power As worst case estimation the calculation can be done with the maximum values of VF = 1.8 V and RthJS = 9 K/W (from datasheet) and assuming no light output. This leads to a dissipated power Pdiss = Pthermai = 12 * A typical RthSB...

Table 1 presents a short product selection guide which highlights products and product families of OSRAM that are suitable for IR illumination applications. Please note that this guide provides just a general overview. For more detailed information and the latest products and updates please visit www.osram-os.com. [3] Dalsa Application Notes, Practical http://www.couriertronics.com/docs/notes/liahting application notes/Practical Radiometrv.pdf amera sensitivity [5] Photonfocus AG, Application Note AN008 Opto Semiconductors

OSRAM OSTAR* OSRAM OSTARE OSRAM OSTAR Opto Semiconductors

automotive qualified according to AEC-Q101 Selection guide: Suitable OSRAM emitters for illumination applications. Wavelength [HITJ Typcial quantum efficiency curves for CCD and CMOS cameras and typical emission spectra Opto Semiconductors