Front lighting for an energy-harvesting luminous-reflective display and its design considerations

Abstract

The color gamut of a luminous-reflective display (LRD) shrinks when the incident light lacks blue photons. A frontlight unit (FLU) emitting in blue can prevent this and ensure readability in the dark. A one-dimensional model was developed to express spectral fluxes emerging from the subpixels in an energy-harvesting LRD (EH-LRD) in terms of its design parameters and the ambient lighting condition. In the experiment, a luminescent layer stacked on an infrared pass filter was excited by monochromatic light from an edge-lit FLU at 405 nm in the dark. The model roughly reproduced the relative peak intensities measured with the three materials (BBOT, Coumarin 6, and Lumogen F Red 305). It quantifies the trade-off between the two objectives of an EH-LRD: displaying images and harvesting energy. Hence, the model might be used to set goals for future developments of materials and components. © The Authors.Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.