Methods for measuring performance of LCoS microdisplays

Abstract— Liquid‐crystal‐on‐silicon (LCoS) microdisplays have unique measurement requirements not shared by direct‐view flat‐panel displays. We developed a series of measurement techniques for measuring reflectance, contrast ratio, and uniformity of LCoS microdisplays. Reflectance is determined by comparing light reflected off of the microdisplay in its “white” state with that reflected off of a calibrated mirror. Several corrections are applied to take into account polarization differences between the reference measurement and display measurement. Contrast ratio is determined by measuring display reflectance in the “white” and “black” states. Reflectance and contrast data can be reduced to scalar values once the spectral content of the intended illumination source is defined. There are several methods for measuring uniformity of contrast and reflectance. An approach that we have developed closely follows the sampled uniformity measurements outlined by VESA for direct‐view displays (Ref. 1).