I will save you a lot of time:
- The number of LEDs chosen is w.r.t.
- 1) Even lighting at the sides w.r.t. frame width. That is based on LED emission angle and assuming a cheap flat edge LGP
- You can increase the spacing, decrease the frame width by optical features on the edge. Issue is patents + cost
- 2) Efficiency - running the LEDs at lower current increases efficiency
- The only losses in the assembly are:
- Coupling efficiency (big)
- losses in going across the LGP (small)
- losses in light extraction (dots, etc.) -- again small
- diffuser (bigger)
There are expensive things you can do to increase coupling efficiency, but the best is just to get the LEDs right up against the edge but not touching the LGP. To eliminate the diffuser, you need more dots, etc. and may still not get the best effect. Of course, you can create specific optical structures to direct the light which does not get more light out, but does improve usage. That requires molding, not patterning with a silk or laser.
With the LEDs up against the LGP (almost), coupling efficiency is good and fixture efficiency is also good. Small LEDs are cheap cheap cheap. Reducing their number has limited value. Eliminating the diffuser is useful, but may not give the desired "look". Pattern, pitch, etc. of the dots is virtually meaningless as what is there now works, works well, delivers an even panel and has limited impact on the efficiency.
Commercially no one cares about that last few percent efficiency. They want it inexpensive and that is just what flat panels are today.
If you want more detail on anything, standard consulting rates will apply