LED panel Light

LED panel light is a flat panel that generates soft uniform LED light output. It usually come in with area size compatible to fluorescent Troffer ceiling light.  Unlike troffer lamp, LED panel lamp usually thick within 2" vs 5" thick of troffer lamp.
There are two ways to build LED panel light.
One way is to use multiple smaller LED to setup a matrix to make evenly light area light source. With no or little diffuser panel, an area panel can emit light evenly. This method requires circuit running at entire panel area, so it suits smaller panel better.

The other method is to set powerful LED light source at edge of panel, then place special light diffuser plate at entire area. This diffuser panel has special cuts and groves to make light through it distributed evenly. This way, the costly LED circuit won't be very large, more suitable for larger panel. However, this kind of diffuser plate won't be very thin and weights a little bit, and a reflective film at back to make sure light only come out at front. Since some light output is reflective light, so its usable lux per wattage is lower than other directional LED light applications.