LED Lighting

Cree has added 50% more light output to its 3.5×3.5mm ‘XP’ format with the introduction of the four-junction XPH35 series. Something like 1,800 lm is available with the device turned up to its absolute maximum of 1.05A, when it typically drops something over 12.3V (~140 lm/W). At the specified current of 350mA (Vf ~11.3V) output of the highest cool white ...

Dielectrics can conduct more heat than copper, claims Sheffield-based Litecool which achieves LED-cooling with a material it has branded Black X. “It is an incredible material. We have always assumed dielectric materials will hinder the thermal performance of our LED packages but this material actually improves it,” said Litecool engineer Robert Corbin. “The thermal resistances of the LED packages we have ...

Yorkshire LED lighting driver maker Harvard Engineering has added ZigBee wireless control to its range of lighting power supplies. The 33W driver, called CLZ and part of the firm’s CoolLED range, offers dimming down to 1% and includes a 2.4GHz radio – either built-in or remote (pictured). Radio communication allows the driver to tap into Harvard’s ‘EyeNut’ monitoring and management system for ...

Finding a way to deposit vertical dielectric barriers has allowed Litecool of Sheffield to make dramatic cut in LED thermal resistance – from 1.25 to 0.5°C/W is one case – see diagram. Dielectric layers are essential to separate electrical conductors but, with a few notable exceptions like diamond, introduce thermal barriers. Spreading heat before it reaches insulating layers with a ...

Ikea’s venture capital arm has invested in a French firm developing and manufacturing 3D LEDs. Grenoble-based Aledia is developing LEDs  for lighting based on a gallium-nitride-on-silicon technology. Ikea believes there is this low-price LED lighting technology for residential use has the potential of faster implementation of the LED technology, leading to savings for customers. Christian Ehrenborg, managing director of Ikea GreenTech ...

Lumileds announced LM-80 test results for its 3535L mid-power lighting LED. 10,000 hours of tests at 55, 85 and 105˚C showed the device exceeds lumen maintenance requirements for both Energy Star and qualification by the DesignLights Consortium (DLC). Projections based on TM-21-11 predict at least 90% of initial light output (L90) will be maintained for a minimum of 60,000 hours ...

Imec and Fujifilm have demonstrated full-colour OLEDs by using their jointly-developed photoresist technology for organic semiconductors, a technology that enables submicron patterning. This paves the way to producing high-resolution and large organic electroluminescent (EL) displays and establishing cost-competitive manufacturing methods. Organic EL displays can be made thin and flexible with excellent response time and contrast ratio. Products require organic EL displays of high ...

French lab CEA-Leti has demonstrated a way to make high-density micro LED arrays for wearable vision. The LEDs are GaN/InGaN – the technology behind white LEDs – with a pitch of 10µm or less. “Currently available microdisplays for both head-mounted and compact head-up applications suffer from fundamental technology limitations that prevent the design of very low-weight, compact and low-energy-use products,” ...

The remarkable photograph of an LED nano-structure was taken by a PhD student at the Eindhoven University of Technology (TU/e). It was taken with a scanning electron microscope (SEM) and was the winning photograph in a competition held by Oxford Instruments Plasma Technology. The winning photograph was submitted by PhD Candidate Victor Dolores-Calzadilla from the Photonic Integration Group at TU/e. Dolores-Calzadilla ...

Osram is taking on chip-on-board LEDs (CoBs) in MR16 lighting applications with a 7x7mm surface-mount (SMD) array LED named Duris S 10. “In view of the surface-mounted design of the LED, a pc board has to be incorporated in the luminaire. This opens up numerous design options such as integrating thermal fuses, connectors or driver components on the LED board,” ...