Chemical compatibility of LEDs application note from OSRAM. Link here (PDF)
The performance and stability of light emitting diodes (LEDs) may be influenced by various chemical incompatibilities arising from chemicals and materials used, amongst other things, in luminaire construction, or by gases in the proximate environment of LEDs during field operation. Nevertheless, LEDs have to fulfill a wide range of customer needs and requirements in indoor and outdoor applications.
This application note provides information about the chemical compatibility of certain substances with LEDs, particularly with regard to some of their basic components. In this context, the main mechanisms of chemical incompatibility are illustrated using examples of blue and white LEDs.
Brief app note from OSRAM, LEDs for heart rate monitoring through skin reflection of emitted light. Link here (PDF)
This application note provides a short introduction into the general use of LEDs for wearable applications, with a focus on heart rate monitoring.
App note from OSRAM about LED rework on signages and their demand for more sophosticated tools. Link here (PDF)
SMT LEDs have became more and more popular in video wall and signage applications, replacing radial LEDs. This leads to more difficulties during the repair or replacement of failed LEDs on PCBs, especially for QFN (Quad Flat No-lead) packages, as there is no exposed lead. This application note provides basic information on how to rework the SMT LEDs in video wall and signage applications. To describe the rework process the DISPLIX Oval LED was chosen an example, as the rework of this LED is more challenging due to the lack of exposed lead and the oval lens on top. However, the procedure is also suitable for other LEDs. In this application note details on the materials used, examples of suitable equipment and the process are presented and described. Finally, the test results of the LED after the rework process are presented, showing that in this case the rework procedure did not cause any damage to the LED itself.
Infrared spectroscopy by OSRAM and their SFH 473X broadband light emitters. Link here (PDF)
Imagine you can check if the mangos on the market are sweet – without even touching them…
Imagine you can verify if your prescribed medical tablets contain the life-saving compound – or if they are counterfeits…
Imagine you can check the calories of your favorite cheese dish – before eating…
Imagine all this is possible with one fingertip on your smartphone…
The SFH 473X series is precisely designed to support this innovation. This note covers briefly the background of spectroscopy and the case for the SFH 473X series.
Different ambient sensors differs on their ability to sense specific wavelength and introduce different ambient levels compared to human eye, here’s a general application note from OSRAM. Link here (PDF)
This application note introduces discusses ambient light sensing. The different types of ambient light sensors are described and related to specific applications.
Application note from OSRAM on driving OLEDs with constant current for longer operation. Link here
The operation of OLEDs with electronic drivers is similar to anorganic LEDs for the most part. In a majority of applications, standard LED drivers may be used also for OLEDs. Nevertheless, there are some important basic rules and OLED specific characteristics, that have to be considered.
OSRAM’s filament looking LED application note. Link here (PDF)
SOLERIQ® L38 (GW T3LxF1) is a filament LED with a beam angle of 360deg for indoor retrofit lighting applications. It combines the advantages of modern LED technology with the aesthetics of traditional light bulbs.
The construction of the SOLERIQ® L38 consists of a ceramic based frame with two alloy connectors at both ends. A number of highly efficient LED chips (depending on the lumen package) is mounted on the ceramic based frame and they are electrically connected through wire bonding, covered by a colored diffused silicone resin.
This application note from OSRAM describes the use of the SFH 4780S in iris recognition (iris scanning) as illumination module. Link here (PDF)
Personal authentication is becoming a key requirement for various electronic devices. Besides of the pin number, today most systems are based on so called biometric “properties”. Biometrics can include fingerprints, facial features, retina, iris, voice, fingerprint, palmprints, vein structures, handwritten signatures and hand geometry. All these biometrics have various pros and cons. However, only iris recognition claims to be a ‘hard-to-spoof’ system in combination with an ultra-low false acceptance rate (i.e. one in a million). Additionally, it also features greater speed, simplicity and accuracy compared to other biometric systems. The traits of iris recognition systems rely on the unique patterns of the human iris which are used to identify or verify the identity of an individual.
This application note from OSRAM describes the possible hazards of infrared LEDs (IREDs) used for lamp applications with respect to the IEC-62471 standard and how to classify IREDs according to different risk groups. Link here (PDF)
As the radiated optical power of light emitting diodes (LEDs) has increased in recent years, the issue of eye safety has received an ever-increasing amount of attention. Within this context there has been much discussion about the right safety standard either the laser standard IEC-60825 or the lamp safety standard IEC-62471 to apply to the classification of LEDs. Before mid 2006 all LED applications were covered by the IEC-60825. Today most of the LED applications are covered by the lamp standard. Other than lasers, lamps are only generally defined in this standard as sources made to produce optical radiation. Lamp devices may also contain optical components like lenses or reflectors. Examples are lensed LEDs or reflector type lamps which may include lens covers as well. The status quo is, that for different applications of LEDs, like data transmission or irradiation of objects, different standards have to be used: data transmission IEC-60825 & lamp applications IEC-62471. Both safety standards do not cover general exposure scenarios and are not legally binding.
LEDs are now mostly used in light projection systems due to their low power requirements, long life and robustness. Here’s an app note from OSRAM for proper integrations on these projection LEDs. Link here (PDF)
This application note provides insights into the use of LED light sources for projection applications. An overview of LED projection systems and their benefits is presented, along with a summary of OSRAM Opto Semiconductors LEDs suitable for these applications. Finally, fundamental design issues related to the use of LEDs in projection modules are addressed.