What are the projectors called that can stand directly in front of the wall and project the image "straight" to the wall? Rather than projectors which require a certain distance to the wall to project the image onto.
They are called Short Throw Projectors and there are models from most projector vendors.
Short throw projectors have very short throw ratios, the distance from projector to screen compared to the screen size. For example, a projector with a 1.5:1 throw ratio would have to be 7.5 feet back to project a 60-inch diagonal image. Short throw projectors could have a 0.37:1 (based on an Hitachi model) throw ratio and can project the same large image from just 1.4 feet away from the screen.