United Nations regulations on the replacement of LED light sources for headlamps

The United Nations regulations have made a series of necessary detailed regulations on various technical parameters of the lamp light source to ensure the safe operation of the lighting and signal lamp devices after replacing the light source. In addition to the general technical requirements for the use of light sources for signal and headlamp installations, there are other specific regulations that describe the requirements for replaceable LED light sources for front fog lamps, adaptive headlamp systems, and various headlamps. Related amendments. Therefore, the use of alternative standardized light sources has many advantages.

Compared with other light sources, standardized LED light sources have very detailed specifications including thermal, photometric, and colorimetric parameters, which greatly simplifies the design of headlamps. This article therefore presents the current state of simplification of regulations on light sources. The content is divided into four parts:

Regulations on light sources in UN regulations

There are three main regulations for light sources, which are directed to three different light source technologies:

Regulation No. 37: Incandescent lamps that emit light by thermal radiation

Regulation No. 99: Gas Discharge Source

Regulation No. 128: LED light source

When the gas discharge source was used in the field of automotive lighting, the No. 99 regulation was specifically formulated, considering the special performance of the gas discharge source different from that of the incandescent lamp. At the same time, in order to ensure color rendering, the requirement for the minimum red component of the radiant light is proposed. The illuminating area of ​​the gas discharge source is not as obvious as the heat radiant source, so a special description of the curvature and diffusivity of the arc is also necessary.

The introduction of LED light source technology requires a corresponding increase in regulations. Unlike other light sources, the photometric and colorimetric performance of an LED depends mainly on the temperature of the wafer, and the change in light output with the applied voltage is completely different from that of the heat radiation source. The illuminating characteristics of different LED arrays are different, and the illuminating area characteristics and the light intensity distribution need to be classified.

All three regulations ensure the safe operation of the lighting and signalling devices after replacing the corresponding light source.

Simplification of regulations for light sources

In order to reduce the administrative burden caused by regulatory amendments, the regulatory agencies hope to reduce the number of lighting regulations.

The ideal goal is to be able to incorporate all types of lighting fixtures through a single regulation, to be as technically neutral as possible, to ensure technological innovation from a performance-oriented perspective, and to revise existing regulations in technological innovation.

For light sources, it is not practical to reduce all regulatory simplifications to one by one due to the type and performance complexity mentioned above. But experts have found a way to reduce the regulatory changes to the light source when promoting technological innovation. A large part of the past revisions to regulations have been limited to the introduction of new light source categories, as product specifications for different categories of light sources contain only specific parameters for a particular category and do not focus on how to adapt to other categories of regulations.

The new method shrinks the three light source regulations into management regulations, technical requirements and tests. The definition of the type and category of the light source becomes part of it, making the process of proposing and introducing new categories in the prior art more simplified.

Regulation No. 128 on the LED light source of the headlamp system

Current Regulation No. 128 for LED light sources does not include provisions for headlamp applications. The regulations on front fog lamps and headlights do not give provisions on the use of LED light sources.

In general, when the light source is used for the headlamp function, it is necessary to satisfy the stricter thermodynamic conditions, greater luminous flux, and stricter geometric constraints of the signal lamp. Therefore, experts are further increasing the definition and requirements of the LED light source in the 128 regulations, in order to ensure the safe replacement of the light source, even the most demanding low beam of the beam, can balance the maximum visibility and minimum glare as much as possible.

The introduction of thermodynamic grading and thermal stability testing at the highest allowable temperature can support the optimal performance of the headlamps under practical application conditions. The choice of different thermodynamic grades can be used for different applications, such as motorcycle headlamps with low thermal boundary conditions and vehicle front fog lamps, and multi-function vehicle headlights near the internal combustion engine with high thermal boundary loads.

Specific provisions for the contrast and uniformity of the light-emitting area of ​​the light source can help the headlamp design have a smaller glare level and a more pronounced cut-off line. The regulations therefore specify the minimum contrast (generally greater than halogen lamps) for LED sources used for low beam lights.

The requirement for uniformity reduces the difference in brightness between the crystal cells in the light-emitting region, and avoids the influence of black spots between some crystal cells. In short, the quality of the beam after the replacement of the light source does not decrease.

Finally, observing the strict limits of the color difference of the light source from different angles can avoid interference to road users.

Advantages of replaceable light sources

The application of standardized LED sources in automotive lighting can reduce the complexity of custom headlights and taillights. With the experience of integrated heat radiation source and gas discharge light source, standardized light source can provide suppliers with more choices, promote market development and performance improvement, and bring more stable, reliable and competitive technology development. Supply chain. Unlike non-standard, non-replaceable light sources or light source modules, the use of alternative light sources simplifies the design of automotive lighting manufacturers and enables cost-effective replacement of damaged components.

The detailed provisions of the regulations on all safety-related technical parameters ultimately simplify the quality inspection and approval process for vehicle taillights and headlights. The replacement of light sources or light source modules requires additional additional models for each new model. Technical test.

In other words, the use of alternative and standardized sources makes it easier to implement more simplified performance-oriented lighting regulations.