Fold out bed?

[davemchine]

I have a small room that my daughters use as a tv room. So there is already a couch and tv. It could easily be a guest bedroom on demand if I could find a decent fold out bed that didn't kill everyone's back. I've seen some couches where the back folds down and forms a very firm mattress for a single person but I don't know what it is called. My only other idea would be a folding mattress on some sort of frame.