Since this an older model that is no longer produced, I assume you are asking a general question.
Ditital TV,Projctors,etc all have a maximum native resoultion that they display.
Compatiably means that will scan convert other resoultions to thier native resoultion.
Here is a link that has a lot of info. John
http://www.cnet.com/4520-7874_1-5102926-1.html?tag=promo2
I'm looking at this projector: JVC DLA-SX21U http://www.projectorcentral.com/JVC-DLA-SX21U.htm
Its native resolution is: 1400x1050 Pixels
Its maximum resolution is: 1600x1200 Pixels
If maximum resolution is the highest input it can accept and scale down to 1400x1050, then how can it be compatible with 1920x1080 HDTV?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic