Tuesday, October 20, 2009

LED Applications

Moodwall / Studio Klink and Urban Alliance



H&M Store in Barcelona / Estudio Mariscal

Le Prisme / Brisac Gonzalez

GreenPix: Zero Energy Media Wall

Tank Street Bridge or Kurilpa Bridge

HQ 13 Parisian subway line / Atelier Phileas

“Running Lights” from Salvini Style

LED Staircase Handrail Concept



Monday, October 5, 2009

Light Emitting Materials - EL wire



Electroluminescent wire (often abbreviated to EL wire) is a thin copper wire coated in a phosphor which glows when an AC Current is applied to it. It can be used in a wide variety of applications- vehicle and/or structure decoration, safety and emergency lighting, toys, clothing etc - much as rope light or Christmas lights are often used. Unlike these types of strand lights, EL wire is not a series of points but produces a 360 degree unbroken line of visible light.



EL wire's construction consists of five major components. First is a solid-copper wire core. This core is coated with phosphor. A very fine wire is spiral-wound around the phosphor-coated copper core. This fine wire is electrically isolated from the copper core. Surrounding this 'sandwich' of copper core, phosphor, and fine copper wire is a clear PVC sleeve. Finally, surrounding this thin, clear PVC sleeve is another clear, colored translucent, or fluorescent PVC sleeve.
An electric potential of approximately 90 - 120 volts at about 1000 Hz is applied between the copper core wire and the fine wire that surrounds the phosphor coated copper core. The wire can be modelled as a coaxial capacitor with about 1 nF of capacitance per foot, and the rapid charging and discharging of this capacitor excites the phosphor to emit light. The colors of light that can be produced efficiently by phosphors are limited, so many types of wire use an additional fluorescent organic dye in the clear PVC sleeve to produce the final result. These organic dyes produce colors like red and purple when excited by the blue-green light of the core.
A resonant oscillator is typically used to generate the high voltage drive signal. Because of the capacitance load of the EL wire, using an inductive (coiled) transformer makes the driver a tuned LC oscillator, and therefore very efficient. The efficiency of EL wire is very high, and thus a few hundred feet of EL wire can be driven by AA batteries for several hours.

Link

Live Wire

Glowire

ThatsCoolWire









Light Emitting Materials - OLED

An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is a light-emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors. (Source: Wikipedia)

Philips OLED glow at 100% design fair

Working method



Schematic of a 2-layer OLED: 1. Cathode (−), 2. Emissive Layer, 3. Emission of radiation, 4. Conductive Layer, 5. Anode (+)

A voltage is applied across the OLED such that the anode is positive with respect to the cathode. This causes a current of electrons to flow through the device from cathode to anode. Thus, the cathode gives electrons to the emissive layer and the anode withdraws electrons from the conductive layer; in other words, the anode gives electron holes to the conductive layer.

Soon, the emissive layer becomes negatively charged, while the conductive layer becomes rich in positively charged holes. Electrostatic forces bring the electrons and the holes towards each other and they recombine. This happens closer to the emissive layer, because in organic semiconductors holes are more mobile than electrons. The recombination causes a drop in the energy levels of electrons, accompanied by an emission of radiation whose frequency is in the visible region.

Link

www.oled-info.com

www.oled-info.com/oled-light

Philips' Lumiblade (OLED lighting) panels


CombOLED transparent white OLED