Cascaded Displays: Spatiotemporal Superresolution using Offset Pixel Layershttps://research.nvidia.com/publication/cascaded-displays-spatiotemporal-superresolution-using-offset-pixel-layers
I was thinking that you could combine two LCDs to improve contrast and/or implement a scanning backlight. Then, I found this video.
They take two LCDs and make one higher-res and higher-fps display by staggering the refreshes.
They demonstrate its use for a prototype VR head-mounted displays (HMDs) and also used with cascaded LCoS projectors. This could be one way to get higher detail without extra bandwidth (sending 2 frames @ 60fps vs 1 frame @ 120fps) or needing higher-density (see caveat below), higher refresh LCDs.
Caveats: Because of LCD color-filters (subpixels), they actually purposely lowered the resolution on each LCD using either 2x2 or 4x4 groups of pixels, so actual results are no better than the original panels (except for faster refreshes). Second, because of a gap between the two LCDs, viewing angles (parallax) changes the offsets affecting the results (noticeable in the video for the prototype HMD). Timings of the LCoS (or alternatively DMD) projectors may need synchronization for best results. Finally, there may be additional latency added for processing when using staggered refresh mode.