OPTICAL SYSTEM

摘要

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.

主权项

1. An optical system, comprising:
an image surface; a stop surface; a first optical stack disposed between the image surface and the stop surface and comprising:
a first optical lens;a partial reflector having an average optical reflectance of at least 30% in a desired plurality of wavelengths; and a second optical stack disposed between the first optical stack and the stop surface and comprising:
a second optical lens;a multilayer reflective polarizer convex along orthogonal first and second axes and comprisingat least one layer substantially optically biaxial at at least one first location on the at least one layer away from an optical axis of the second optical stack and substantially optically uniaxial at at least one second location away from the optical axis; anda first quarter wave retarder disposed between the reflective polarizer and the first optical stack, wherein substantially any chief light ray that passes through the image surface and the stop surface is incident on each of the first optical stack and the second optical stack with an angle of incidence less than about 30 degrees, and wherein the multilayer reflective polarizer has at least one first location having a radial distance, r1, from an optical axis passing through an apex of the multilayer reflective polarizer and a displacement, s1, from a plane perpendicular to the optical axis at the apex, s1/r1 being at least 0.2, and wherein for an area of the reflective polarizer defined by s1 and r1, a maximum variation of a transmission axis of the reflective polarizer is less than about 2 degrees.