Cascaded display quadruples LCD pixel density
NVIDIA has created a prototype VR display boasting four times the pixel density available in similar headsets. Because the LCD screens in any VR headset are situated close to the eyes of the wearer, large pixels can sometimes be apparent in the images which diminishes the overall VR effect. It has overcome this problem by combining two standard LCD panels together in a cascaded display.
By extracting the layer responsible for the visibility of individual pixels and laying it over another panel of the same type, the pixels on the lower panel become divided into four. When pixel brightness on the top layer changes it also affects the four ‘new’ pixels that the viewer sees, so the NVIDIA had to develop software to correctly translate the feed for each layer.
The method of design means that overall brightness output is lower, but this is not thought to be a problem. On the flipside, the screens can display a faster frame rate if the panels are arranged to refresh out of sync with one another. This enables the headset wearer to see new frames at double the rate each panel is updating.