Patent ID: 11927783
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. An optical system comprising:
one or more optical lenses;
a partial reflector disposed on and conforming to a curved major surface of the one or more optical lenses;
a reflective polarizer disposed on and conforming to a major surface of the one or more optical lenses and comprising a plurality of polymeric layers, each polymeric layer having an average thickness of less than about 500 nm, such that for a substantially normally incident light in a predetermined wavelength range extending at least from about 450 nm to about 600 nm:
the partial reflector has an average optical reflectance of at least 30%; and
the plurality of polymeric layers has an average optical reflectance Rs for a first polarization state, 50%≤Rs≤95%, and an average optical transmittance Tp≥80% for an orthogonal second polarization state; and

an exit surface, the optical system configured to display an image to a viewer positioned proximate the exit surface;
such that for an incident cone of light having a full cone angle of at least 10 degrees that is incident on the optical system from an object comprising a spatial frequency of less than about 1 line pair per millimeter, and exits the optical system through the exit surface as an exiting cone of light, when the exiting cone of light is imaged proximate the exit surface, the image has a plurality of alternating bright and dark regions, Ib being an average brightness of central 50% regions of the bright regions, Id being an average brightness of central 50% regions of the dark regions, Ib/Id≥50.