Contrast and colorimetry measurements versus viewing angle for microdisplays

The response of a microdisplay device as a function of viewing angle is a major element in the quality of a microdisplay-based system. Such measurements are tricky and time intensive when realized with mechanical equipment. A new system, optimized for microdisplay and based on Fourier Optics is described. It realizes luminance and color coordinates measurement up to +/-30° with 0-360° azimuth angles in one shot (less than one minute) with a resolution better than 0.1 degree. This paper shows how characterization of the microdisplay itself, or combined with its illumination, can be performed for emissive, transmissive, reflective, on and off axis illuminated microdisplay devices. In particular, how its long working distance allows the equipment to carry out measurement even through beam splitter or complicated combination cubes is described. The new tool is shown to be adequate both for R&D and manufacturing teams.