US Patent 7542209 Compact head mounted display devices with tilted/decentered lens element

One embodiment of the invention comprises a simplified light-weight head mounted displays comprising an off-axis combiner and imaging optics defining an optical path. The imaging optics comprises a lens group comprising a plurality of lenses in the optical path. The lens group has a first optical axis. Each of said plurality of lenses have optical axes collinear with the first optical axis. The imaging optics further comprises a single lens element in the optical path having a second optical axis that is different from the first optical axis. The single lens element has positive optical power and is the only lens element in the optical path between the lens group and the combiner that has an optical axis collinear with the second optical axis.