Hanging heavy stuff from drywall ceiling?

So I need to hang a 20 pound projector screen from my ceiling. I'm standing here with my screws and drill and I'm terrified. Whats the best way to hang this thing? My stud finder shows a beam of some kind, but I think it is just thin metal. I cant get into the ceiling since i live in an apartment. One day I'll need to take it back down. The screen weights 20lbs, so the screws on the ends would hold 10 each.