US Patent 8471807 Calibration of displays having spatially-variable backlight

A display has a screen which incorporates a light modulator. The screen may be a front projection screen or a rear-projection screen. The screen is illuminated with light from an illuminator comprising an array of individually-controllable light sources. The light sources and elements of the light modulator may be controlled to adjust the intensity and frequency of light emanating from corresponding areas on the screen. The display may be calibrated to compensate for differences in intensities of the light sources.