Tag Archives: OLED

OLED Lighting in the Auto Industry

In recent years, a number of industries have started using Organic Light-Emitting Diodes (OLEDs) in diverse ways. The automotive industry, in particular, has seen a huge potential in OLEDs. For instance, very soon Audi will be coming up with OLED taillights. At present Audi has presented prototypes of the taillights. At the LOPEC Congress, Audi provides advanced insights into the needs of the automotive industry that the deployment of OLEDs will require to meet, and the future of automotive lighting.

So far, there have been plenty of developments. At LOPEC, Audi demonstrated prototypes of their OLED taillights, which they claim have reached production stage. However, using OLEDs in vehicles has always been a challenge, although OLED lighting installations and table lamps have been around for a while, and these are in use in museums, clubs, and restaurants.

Difficulties of Using OLED in Automobiles

Major hurdles OLEDs have to cross when in use in automobiles are they have to withstand humidity, heat, cold, UV radiation, and constant vibration. All these can reduce the life span of OLEDs drastically. Audi claims to have solved this problem by encapsulating their displays hermetically, which they claim will make the displays as stable as LEDs.

Why Use OLED in Place of LEDs?

Regular LEDs act as point sources of light, and it requires substantial development work for generating an even light from them. On the other hand, OLEDs are evenly radiating sources of light, and they naturally produce a uniform illumination. Moreover, their thickness is only about a millimeter, which makes OLEDs more suitable for automotive design.

Designers find OLED appearance is high quality, both when off and on. This is because it has a simple and clean surface. As design is an important aspect of the automotive industry, it makes OLEDs ideal for such use. Most automobile owners expect a certain lifestyle from their vehicles, apart from its functional use of transportation from point A to point B.

However, for use as turn signals and brake lights, the light intensity from OLEDs is not adequate, and will have to be increased. The automotive industry is also working on using flexible OLEDs. At present many are using glass-based OLEDs, but these are rigid, and using plastic foil substrates as the base for OLED is opening up a whole new world of opportunities for the designers.

Audi is expecting LOPEC will open up a huge bandwidth of business and research institutes for them. They expect to hold discussions with specialists using this breadth of activity, and to meet other OLED manufacturers and materials developers.

What the Future Holds?

In about a decade from now, the world will be witnessing innovations in vehicle lighting that most can only dream about today. As it is, a vehicle’s lighting system already functions as a form of communication—hazard lights, turn signals, brake lights, for example. In the future, driverless cars will need to interact with others on the road with even greater sophistication. One of the visions Audi has is of a three-dimensional OLED display extending the entire tail of the vehicle, on the panel of the body, and integrated OLED within the windshield.

LED Light Guides Equal OLED Performance

The visual impact of OLED panels is hard to resist. Their luminosity is seductively stylish and sleek. Fashion-forward lighting designers prefer the eerily-even silky glow of the OLEDs, even though these are more expensive, have a short lifetime and can be damaged more easily than other light emitting panels. Now GLT or Global Lighting Technologies, with their edge-lit LED-based light guide technology, is about to turn the tables on OLEDs.

The latest product from GLT, a 4×4 inch LED-based light guide, demonstrates this technology specifically. Compared to an OLED panel, the GLT light guide has better durability, higher efficiency, longer life and is cheaper as well.

Applications that would normally use an OLED panel, can easily use the LED-based 4×4 inch square GLT light guide as a more durable and affordable solution. GLT has designed these light guides for use in general lighting applications and they offer diffused light output very similar to that from OLEDs, but at a much lower cost.

Offering enhanced light extraction, the light guide is very thin – only 3.5 mm. The panel itself measures only 2 mm, considerably thinner than products GLT made earlier. When in use, industry standard LEDs will typically light it up from the edges, with only a small frame concealing the LEDs. The current product gives out 250 lumens when fully powered, while the efficiency per watt is over 115 lumens.

GLT produces several types of molded light guides. All the products, including the new 4×4 backlights, are made using an efficient light extraction technology. A high-precision micro-molding process impresses optical features within the light guide. By arranging the features to provide a unique transition area, light spreads uniformly and precisely over each point across the panel. GLT has several standard patterns that they mold into the light guides. They can customize each pattern and meet any application virtually.

GLT develops their light guides in very thin packages and designs mechanical holding features into the backlights. That allows the host application to carry the entire display assembly and if that is not possible, use chip-on-flex or chip-on-glass type of assembly. That helps to reduce the parts count and material and assembly costs.

According to GTL, their light extraction technology delivers better optical performance than that offered by V-groove or stamped, chemical or laser etching and printing processes. Additionally, their process is more repeatable. After having demonstrated their light diffusion technology for a few years, GTL has now incorporated it into some of its high-end lighting products.

With their light diffusion technology, GLT offers a large variety of design options to the luminaire designers. Some of these designs can already be seen in the round 12-inch diameter pendant light. This clever design achieves results remarkably like an OLED. It uses a light guide incorporating LEDs along its inner circumference and they emit light in multiple directions.

Panasonic uses light guides from GLT in commercially available fixtures meant for mounting on ceilings. In the fixture, multiple light guides create discrete distribution patterns. These include spot lighting, downward flood lighting and upward ambient lighting within the room.