US Patent 11787137 Optical system

An optical system includes a partial reflector having an average optical reflectance of at least 30% in a desired plurality of wavelengths, a display panel disposed to emit image light toward the partial reflector, and a multilayer reflective polarizer disposed proximate the partial reflector. The multilayer reflective polarizer is curved about two orthogonal axes and includes at least one layer substantially optically uniaxial at at least one location. The image light is transmitted by the multilayer reflective polarizer after it is first reflected by the multilayer reflective polarizer. A quarter wave retarder may be disposed between the reflective polarizer and the partial reflector.