REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

The estimation of the LED back light lifetime

branko Livada

Vlatacom Institute, Belgrade, branko.livada@vlatacom.com

Abstract: Display light output constancy (luminance level, chromatic performances) during the lifetime is one of the most important requirements especially in the case of ruggedized AMLCD displays. Display backlight design solutions have a key role to fulfill display light output requirements. The backlight reliability and lifetime definitions and influencing factors are discussed. The experimental set-up for LED backlight lifetime determination is described. The LED backlight lifetime determination is based on the experimental set-up using accelerated testing. The lifetime measurement experimental results are presented and discussed. Experimental results are used for backlight LED selection and backlight design recommendations. Experimental results are revisited and discussed in the light of the current standards related to lifetime definition of the solid state light sources and luminaries.

Keywords: Ruggedized displays, Backlight, LED backlight, LED lifetime, Accelerated testing.