US Patent 11573420 Augmented reality systems with dynamic see-through transmittance control

An augmented display system with dynamic see-through transmittance control is disclosed. The augmented display system includes: an augmented display screen; a tandem electrochromic (EC) filter disposed over the augmented display screen. The tandem EC filter includes a first window having a dominant first transmittance characteristic and a second window having a dominant second transmittance characteristic; and an augmented display transmittance controller configured to individually control the activation of the first window and the second window of the tandem EC filter, wherein the augmented display transmittance controller is configured to: determine from an ambient light sensor output the transmittance required from the first window and the second window for a selected augmented display luminance; and apply appropriate drive voltage waveforms to the first window and the second window to achieve the determined transmittance.