Patent ID: 11874576
Assignee: REALD SPARK, LLC
Field: Optics (Instruments)
Classification: CPC G | IPC F  G

Claim 15:
16. A display device according to claim 1, wherein the plural polar control retarders further comprise two passive retarders which have optical axes in the plane of the two passive retarders that are crossed, the two passive retarders being respectively included in the at least one air gap output retarder and the at least one air gap input retarder, the two passive retarders introducing no net, relative phase shift to orthogonal polarisation components of light passed by the display polariser along the first axis, and a one of the two passive retarders which is arranged in the at least one air gap input retarder being arranged to convert linearly polarised light passed by the display polariser into circularly polarised light.