CSpace high-resolution volumetric 3D display

Abstract

We are currently in the process of developing a static-volume 3D display, CSpace® display, that has the capability to produce images of much larger size than any other static-volume display currently under development, with up to nearly 800 million voxel resolution. A key component in achieving the size and resolution of the display is the optical system that transfers the pixel data from a standard DMD projection unit to the voxel size required by the display with high contrast and minimal distortion. The current optical system is capable of such performance for only small image sizes, and thus new designs of the optical system must be developed. We report here on the design and testing of a new optical projection system with the intent of achieving performance close to that of a telecentric lens. Theoretical analysis with Zemax allowed selection of appropriate lens size, spacing, and focal length, and identified the need for tilting the assembly to produce the desired beam properties. Experimental analysis using the CSpace® prototype showed that the improved beam parameters allowed for higher resolution and brighter images than those previously achieved, though their remains room for further improvement of the design. Heating of the DMD and its housing components were also addressed to minimize heating effects on the optical system. A combination of a thermo-electric cooler and a small fan produced sufficient cooling to stabilize the temperature of the system to acceptable levels.