Optical system for displaying an object to a viewer
An optical system including one or more optical lenses, at least one retarder layer, a reflective polarizer, and a partial reflector is provided. The at least one retarder layer may include first and second retarder layers having different wavelength dispersion curves. The at least one retarder layer may include a first retarder layer having a non-uniform fast axis orientation and/or a non-uniform retardance.
1. An optical system for displaying an object to a viewer, comprising:
one or more optical lenses having at least one curved major surface;
a reflective polarizer disposed on and conforming to a first major surface of the one or more optical lenses, the reflective polarizer substantially reflecting light having a first polarization state and substantially transmitting light having an orthogonal second polarization state;
a partial reflector disposed on and conforming to a different second major surface of the one or more optical lenses, the partial reflector having an average optical reflectance of at least 20%;
a first retarder layer disposed on and conforming to a third major surface of the one or more optical lenses; and
a second retarder layer disposed on and conforming to a fourth major surface, different than the third major surface, of the one or more optical lenses, such that relative to the first polarization state, the first retarder layer has a substantially uniform orientation and non-uniform retardance across the first retarder layer, and the second retarder layer has a substantially uniform retardance and non-uniform orientation across the second retarder layer.
2. The optical system of claim 1 , wherein the first retarder layer comprises a first spin-coated retarder layer having a smaller average first physical thickness and the second retarder layer comprises a second spin-coated retarder layer having a greater average second physical thickness.
3. The optical system of claim 1 , wherein the first retarder layer has a first wavelength dispersion curve and the second retarder layer has a different second wavelength dispersion curve.
4. The optical system of claim 1 having an optical axis intersecting the first retarder layer at a first origin and the reflective polarizer at a second origin, a light ray propagating along the optical axis passing through the one or more optical lenses, the partial reflector, the reflective polarizer and the first retarder layer without being substantially refracted, wherein the reflective polarizer has orthogonal block and pass polarization states at the second origin, and wherein for a first light ray propagating along the optical axis and incident on the first retarder layer at the first origin and having a predetermined wavelength and the block polarization state, the first light ray comprises the first polarization state when first incident on the reflective polarizer and the second polarization state when second incident on the reflective polarizer, a difference between the first and block polarization states being less than a difference between the second and pass polarization states.
5. The optical system of claim 1 having an optical axis intersecting the first retarder layer at a first origin and the reflective polarizer at a second origin, a light ray propagating along the optical axis passing through the one or more optical lenses, the partial reflector, the reflective polarizer and the first retarder layer without being substantially refracted, wherein for a light ray having the first polarization state at a predetermined wavelength passing through the first origin, the first retarder layer converts the light ray to an elliptically polarized light for the light ray propagating along the optical axis, and to a circularly polarized light for the light ray propagating along a direction oblique to the optical axis.