We don’t recall having heard the term ‘collimated display’ before, but we’ve seem them in action. These are mirrored projection display that give the viewer a true peripheral vision experience thanks to well-designed optics. Here is a project that [Rob] and [Wayne] have put a ton of time into. It’s their own version of a DIY collimated display that uses a shop vac and Arduino to form the screen shape.
The frame above is the structure that will support the screen. A sheet of mylar was later attached to the edges of that frame. That is pulled into place by the suction of the vacuum. But it needs to be stretched just the right amount or the projected image will be distorted. They’ve got something of a PID controller to manage this. A valve box was built to vary the amount of vacuum suction inside the screen’s frame. A switch positioned behind the mylar sheet gives feedback to the Arduino when the screen reaches the appropriate position and a servo closes off the suction box. If you lost us somewhere in there the description in the clip after the jump will help to clear things up.
Here’s an unrelated project that implements the same concept on a smaller scale.