An optical system includes a partial reflector having an average optical reflectance of at least 30% in a plurality of wavelengths, an image source disposed to emit image light toward the partial reflector, and a reflective polarizer disposed proximate the partial reflector. The reflective polarizer is curved about two orthogonal axes and can include at least one layer substantially optically uniaxial at at least one location. The image light may be transmitted by the reflective polarizer after it is first reflected by the reflective polarizer. Substantially any chief light ray having at least first and second wavelengths at least 150 nm apart in the plurality of wavelengths and emitted by the image source and transmitted by a stop surface or exit pupil of the optical system has a color separation distance of less than 1.5 percent of a field of view.

An image display device of the present disclosure includes an image light generating device, a first, a second, a third, and a fourth optical unit. A first intermediate image is formed between the first and the third optical unit. A pupil is formed between the second and the fourth optical unit. A second intermediate image is formed between the third and the fourth optical unit. An exit pupil is formed at an opposite side of the fourth optical unit from the third optical unit. The image light generating device includes a first, a second, a third light emitting panel, and a color synthesis element. The color synthesis element is constituted of a cross dichroic prism including a first and a second dichroic film that intersect with each other. Each of the first and the second dichroic film does not have a polarization separation characteristic.

A beam expander including a partial reflector, a reflective polarizer curved about two orthogonal axes and a quarter wave retarder disposed between the reflective polarizer and the partial reflector is described. The beam expander is adapted to receive an input light beam incident on the partial reflector and transmit an expanded output light beam. Illuminators and projection systems including the beam expander are described.

An eye-mounted device includes a contact lens and an embedded imaging system. The front aperture of the imaging system faces away from the user's eye so that the image sensor in the imaging system detects imagery of a user's external environment. The optics for the imaging system has a folded optical path, which is advantageous for fitting the imaging system into the limited space within the contact lens. In one design, the optics for the imaging system is based on a two mirror design, with a concave mirror followed by a convex mirror.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

Optical systems including an image surface and an exit surface are described. First second and third optical lenses, a partial reflector, a multilayer reflective polarizer and a retarder are disposed between the image surface and the exit surface. At least one location on at least one layer of the multilayer reflective polarizer is substantially uniaxially oriented. Each chief light ray that passes from the image surface to the exit surface is incident on the multilayer reflective polarizer with an angle of incidence less than about 30 degrees. The optical system may include a plurality of major surfaces disposed between the image surface and the exit surface where each major surface is convex toward the image surface and where at least six different major surfaces have six different convexities.

An optical system includes a reflective surface, a display adapted to emit image light toward the reflective surface, and a multilayer reflective polarizer disposed proximate the reflective surface. The multilayer reflective polarizer is curved about two orthogonal axes and includes at least one layer that is 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 head-mounted display includes a first optical system and a second optical system disposed proximate the first optical system.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

Optical systems including an image surface, a stop surface, a partial reflector disposed between the image surface and the stop surface, a reflective polarizer disposed between the stop surface and the partial reflector, and a quarter wave retarder disposed between the reflective polarizer and the partial reflector are described. The reflective polarizer is convex along two orthogonal axes. The reflective polarizer may be a thermoformed multilayer reflective polarizer.

An optical stack includes first and second lenses, a partial reflector, a reflective polarizer, and a retarder. The reflective polarizer is curved about two orthogonal axes and includes at least one layer that is substantially optically uniaxial at at least one location. An optical system includes the optical stack disposed between an image surface and an exit surface. The optical system is configured such that substantially any chief ray transmitted from the image surface to the exit surface is first incident on the reflective polarizer at an angle of incidence less than 30 degrees.