Quantification, assesment and improvement of luminance gradient in rear lightRoadmap toward design o

Mrs.Sara Paroni

AutomotiveLighting Rearlamp Italia

R&D /ELT department

Tolmezzo, Italia

e-mail:sara.paroni@al-lighting.com

Mr.Bertrand de l’Éprevier

AutomotiveLighting Rearlamp France

R&D/ ELTdepartment

Trappes,France

e-mail:bertrand.deleprevier@al-lighting.com

Abstract—Last decade has seen huge progress in terms of light source, moldingtechnologies and optical simulation. The lamp is more and more part of thecustomer signature, recently also as a matter of lit appearance. This hasdriven car manufacturer to define their own criteria for the evaluation. Then thehomogeneity was addressed to the light designer as a “must have”. What weresome wishes from stylist a couple year ago, to emphasis the brand identity andthe appearance perceive quality, is now an entity to consider by objectiverequirements to be managed by optical calculation, simulations andmeasurements.

This paper describeson one hand the approach of Automotive Lighting regarding consideration ofhomogeneity requirements to be applied in the product development process, andon the other hand possible solutions for product optimization.

In the field ofdevelopment process, the investigation of the theoretical meaning of luminancehomogeneity and the associated physical units is described. Also ways tosimulate luminance homogeneity and ways to evaluate OEM criteria are addressed.Finally, an extensive work driven together with the OEM to define some postprocessing methodology and assessment criteria to turn it into a SMARTrequirement is proposed.

Regarding the productoptimization, an overview of which technical solution gives the best appearanceand homogeneity is addressed. The example based on combination of white shell reflectorand opalin diffusion screen is detailed.

The final statementwill give some perspective of future optimization in the development processand the product: refinement of luminance measurement of post-processing,correlation with simulation, optimized technical solution with light guide,light curtain and other light sources.

Keywords:luminance, homogeneity,gradient assement, standardization