Patent attributes
In addition to varying the luminance and chrominance levels of each voxel in an image, a viewing distance for objects within the image is varied to display a multi-focal, three-dimensional image. The focal distance of the voxels is determined by a depth map that indicates a fixation viewing depth of each object. When the image is viewed, there is a natural correspondence between the accommodation and vergence of the viewer's eye. The focal distance of the voxels displayed in the image are modulated using, for example, one or more dynamically variable focus mirrors or lenses, a plurality of fixed focus mirrors or lenses having different focal distances, a plurality of different length optical paths with different focal distance ranges, or at least one spatial light modulator. Light used to produce the image is scanned in two orthogonal directions either before or after the light is focus modulated.