A volumetric display from Act Research enables observers to view three-dimensional images without the use of special eyeglasses or helmets. Viewing the images requires no special glasses or helmet. Separate viewers can walk around the display, and all see the image simultaneously from multiple viewpoints. Since the 1960s, the development of volumetric displays has taken various routes, including the use of lasers as a light source. Act Research followed a different approach, modulating light from a metal halide lamp to flash successive picture frames on a rotating two-dimensional screen.
Cost is really the major advantage, especially when projection of color images is considered.
Of course, size and weight advantages of lamps over lasers are also valid. Tsao was attracted to Displaytech's spatial light modulator for its high frame rate. Displaytech is the only choice because they have a high frame rate to create three dimensions. Act Research's current model is a demonstrational prototype that can image medical data in three dimensions. Tsao explored other liquid crystal modulators but found that their frame rates were too slow.