This investigation demonstrates a novel light-emitting system with an array of blue light-emitting diodes (LEDs). Unlike a conventional lighting system that is constructed from white LEDs, the proposed planar lighting system uses blue LEDs to excite a YAG : Ce3+ yellow phosphor film remotely, yielding a high lumen efficiency with uniform and planar light-emission. The phosphor film herein acts as a wavelength converter and a light diffuser simultaneously. The optical properties of the proposed lighting system, angular color deviation and light-emitting uniformity, are studied. Eventually, a high lumen efficiency (73.0 lm/W) and thin lighting module (7.5 mm-thick) was demonstrated without the use of any conventional diffuser plate or light guiding plate (LGP). A low color deviation (Δu′v′ = 0.025) and a high light-emitting uniformity (Uniformity = 82%) were achieved. Hence, the proposed lighting system exhibited superior optical performance using a compact module.
- Angular color deviation
- indium gallium nitride (InGaN)
- light-emitting diodes (LEDs)
- remote phosphor
- yttrium aluminum garnet (YAG)