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

Claim 3:
4. The optical system of claim 1 being configured to display an image to a viewer positioned proximate an exit surface of the optical system, wherein 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 that 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 a central 90% of the bright regions, Id being an average brightness of a central 90% of the dark regions, Ib/Id≥50.