A holoprojector is a display technology capable both of 2D image displays on various surfaces and of 3D projecting.
Holoprojectors may for instance be installed in paper bags to allow billboards filled with advertisements to be projected over them.
Most museums have proper 3D projectors that place an image of the item over the actual display so that viewers can get a full look at it without having to move too much.
The Caldari ship captain and scientist Trevor Kekkonen had one of these at his lab office at the CreoDron factory orbiting Atlulle III. When Orsetta Lexmoreau's team had completed the development of one of Trevor's projects, she used some sort of remote control to switch on Trevor's projector to display a blueprint.
The blueprint was presented as a series of three-dimensional images floating over his lab desk, moving rapidly in successive sequence from mathematical equations to subatomic particle diagrams; from molecular compound models to exploded-view engineering drawings of mechanical components; and finally to the animation of those same components converging perfectly with each other to form schematics of the finished product. It then displayed performance and statistical information scrolling down along each side of the image.
Duvolle Laboratories had holograms in meeting rooms. The screensaver was revolving pies and charts. A laser pointer could be used to highlight certain areas of the projection.