Elongated collimator for pupil placement

Abstract

An elongated collimator collimates light generated by a microdisplay for coupling to an exit pupil expander of a waveguide. The elongated collimator includes a first portion having four or more freeform surfaces that fold the optical path of the light and then direct the light via total internal reflection through an elongated flat (or nearly flat) second portion of the collimator to form a pupil within a lens of an eyewear display device. The elongated collimator delivers collimated light to a pupil located toward the center of the lens where the light can be collected by an exit pupil expander having a relatively small footprint.

Dependencies are inferred from the claim text.