Luminous license plate
Self- luminous license plates ( SLN ) or luminous license plates are vehicle license plates that do not have to be illuminated by an external light source in order to be visible and legible in the dark in order to comply with the legal requirements for license plate lighting.
License plates illuminated from behind with incandescent lamps were developed as early as the 1930s, but the space requirement was significantly higher than with the solutions customary at the time, so they were only installed in a few car models and could not be retrofitted.
technology
Deviating from the actual original name, various techniques are mentioned in a context or used improperly in common parlance. For example, backlit vehicle license plates or license plate frames that are sparsely illuminated with LEDs are also referred to as “self-luminous license plates”, even though they are not actually self-luminous license plates.
The following systems are known:
Electroluminescent self-luminous label
In 2002 the Swiss company Lumitec AG developed a specially sealed plastic license plate holder housing together with Eisenacher FER Fahrzeugtechnik , which was presented in 2003 at the 60th IAA in Frankfurt. With this system, the individual black plastic letters and numbers were applied directly to a light-conducting, transparent plastic disc, which was underlaid with an EL film . The system had a compact design, disadvantageous were the extremely high price and the complex production of the lettering. This procedure was the first self-luminous license plate system and for the first time received limited approval from the Ministry of Transport for use on the VW Phaeton . However, the road approval for it expired in 2005. The system was the forerunner of today's self-luminous license plates with electroluminescent foil.
Luminous license plate with EL film
The only license plate that can really be described as a "self-luminous license plate" was developed by the companies Lighttech GmbH and A. Sievers GmbH together with other partners. In this process, the label is embossed directly on a EURO aluminum plate, which has been laminated with a special electroluminescent, so-called EL film and a semi-transparent reflective film. On the back of the license plate is the output of a ribbon cable that is connected to the vehicle's on-board voltage using a 12 V inverter . The system was further developed by A. Sievers GmbH in the 2000s under the name G-elumic and made ready for series production. The Federal Motor Transport Authority first issued this system on February 27, 2007 under ABG no. K555 the official ECE-4 approval for all motor vehicles. The number plates are offered for cars in the size 520 mm × 110 mm and for motorcycles in the size 180 mm × 200 mm.
This system ensures a remarkably bright and even, homogeneous illumination of the entire license plate; this eliminates the standard number plate lighting. The unchanged flat design of the aluminum plate allows it to be installed almost without restriction on any vehicle with almost any standard license plate holder. After initial failures, longer field tests have now confirmed the suitability for everyday use. The disadvantage is currently the higher purchase price.
License plate backlit with LED
The American conglomerate 3M developed a label system backlit with LEDs . For this purpose, a strip equipped with LEDs was built into a plastic frame about 15 mm thick and glued to a transparent plastic board. The specially developed, flexible, reflective, semi-transparent and embossed plastic label was applied to this disc. Then both frame parts were connected to one another. The Federal Motor Transport Authority issued an authorization for this procedure on July 10, 2006 under ABG no. K513 a general type approval. In November of the same year these plates came on the market. However, four years later, in 2010, sales were stopped again.
The disadvantages of this system were, among other things, the bulky construction format, leaks and the associated electrical susceptibility. In addition, the embossing companies required special embossing tools for embossing the flexible plastic labels.
License plate holder illuminated with LED
In December 2008 the company Utsch AG from Siegen brought an illuminated license plate holder called “Erulux” onto the market; under the ABG no. K583 has a general type approval. With this system, the standard aluminum license plate is placed in a two-part, 17 mm thick plastic frame and locked. A conductor surface equipped with 20 LEDs and a transparent plastic disk then ensure sufficient license plate illumination.
The advantage of this system is that every commercially available license plate can continue to be used and changed in the appropriate format. Disadvantages include the slightly higher purchase price, the heavy frame, comparable to the 3M system, not a completely uniform light image and the fact that the license plate has to be removed from the carrier for each main inspection . The light cones of the LEDs are clearly visible and make the center of the license plate appear a little pale.
Luminous license plate with LED
The company Sun-Tec developed a labeling system in which a conventional aluminum plate, a semi-transparent and semi-reflective foil are glued together. In between, a thermoplastic containing an LED-equipped transparent film is stored. These foils are usually also used in transparent LED glasses. This technology allows subsequent embossing of the circuit board, which is about 1.6 mm thicker than a conventional license plate.
The all-round clearly visible LED light cones prove to be a disadvantage. An ABG is not yet known.
background
In most European countries, license plate lighting from the outside using incandescent lamps and, more recently, LEDs is mandatory. The Federal Motor Transport Authority in Germany initially issued an exception regulation for the approval of "self-luminous license plates" until April 29, 2005. In July 2006, the 3M company in Germany first received a general design approval (ABG) for the license plate they had developed.
The basis for this is the changed and accordingly adapted former StVZO, now FZV, under TA22. The approval permit (ABG) currently only exists for attachment to the rear of the vehicle. The standard license plate lighting can be switched off when using an illuminated license plate system.
Advantages and disadvantages
The developers of self-illuminating labeling systems cite the following advantages:
- better readability through even, homogeneous illumination
- Less shadow formation due to the cone of light on the embossed license plate
- better visibility in difficult light and weather conditions
- better visibility from almost all angular positions
- lower power consumption
- more options for the automotive designer
- More cost-effective production of body parts for automobile manufacturers, since the 8 ° angle of inclination required worldwide for license plates at the rear is no longer required.
One disadvantage is the currently still higher price compared to a non-self-illuminating license plate.
Individual evidence
- ↑ G-elumic light label. (No longer available online.) Archived from the original on December 18, 2014 ; Retrieved February 6, 2013 .
- ↑ G-elumic®, self-luminous license plate, luminous films - home page. Retrieved February 6, 2013 .
- ↑ 3M Luminous License Plate (SLN) Innovative license plate celebrates its street premiere . Press release. 3M Germany, March 23, 2006, accessed December 28, 2010 .
- ↑ Product information ERULUX LED license plate frame. Retrieved February 6, 2013 .