Patent ID: 8781794
Filing Date: 2014-07-15
Classification: G02B,G06F

Abstract:
1. A computer-based method for designing a free space reflective optical surface for use in a head-mounted display that reflects a virtual image of a display surface for viewing at a preselected spatial location by a user's eye, the method comprising using one or more computers to perform the steps of: (a) representing, by the one or more computers, the display surface by a plurality of display objects based on optical properties not tied to a particular substrate or plane; (b) representing, by the one or more computers, the free space reflective optical surface, not tied to a particular substrate or plane, by a plurality of surface elements, each surface element being characterized by (i) a spatial location relative to the display surface, a nominal user's eye, and the preselected spatial location of the virtual image, (ii) a normal, and (iii) a radius of curvature; (c) associating, by the one or more computers, each display object with at least one surface element in the direction of which a virtual image of the display object at the preselected spatial location will be displayed to the nominal user's eye, each surface element being associated with a single display object; (d) for each surface element: (e) calculating a smoothed free space reflective optical surface based on the final spatial locations, the final directions of the normals, and the final radii of curvature of the plurality of surface elements.