Light Attenuation Display: Subtractive See-Through Near-Eye Display via Spatial Color Filtering

We present a display for optical see-through near-eye displays based on light attenuation, a new paradigm that forms images by spatially subtracting colors of light. Existing optical see-through head-mounted displays (OST-HMDs) form virtual images in an additive manner-they optically combine the light from an embedded light source such as a microdisplay into the users' field of view (FoV). Instead, our light attenuation display filters the color of the real background light pixel-wise in the users' see-through view, resulting in an image as a spatial color filter. Our image formation is complementary to existing light-additive OST-HMDs. The core optical component in our system is a phase-only spatial light modulator (PSLM), a liquid crystal module that can control the phase of the light in each pixel. By combining PSLMs with polarization optics, our system realizes a spatially programmable color filter. In this paper, we introduce our optics design, evaluate the spatial color filter, consider applications including image rendering and FoV color control, and discuss the limitations of the current prototype.