Patent attributes
An optical system for displaying an image to a viewer includes a partial reflector, a reflective polarizer, and a first retarder layer. A light ray propagates along the optical axis and passes through the plurality of optical lenses, the partial reflector, the reflective polarizer, and the first retarder layer without being substantially refracted. For a cone of light incident on the optical system from an object comprising a spatial frequency of about 70, 60, 50, 40, or 30 line pairs per millimeter and filling the exit pupil with a chief ray of the cone of light passing through a center of the opening of the exit pupil of the optical system and making an angle of about 20 degrees with the optical axis, a modulation transfer function of the optical system is greater than about 0.2.
