Patent ID: 11892717
Assignee: REALD SPARK, LLC
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A display device for use in ambient illumination comprising:
a spatial light modulator arranged to output light, wherein the spatial light modulator comprises a display polariser arranged on a side of the spatial light modulator, the display polariser being a linear polariser;
a view angle control arrangement comprising:
an additional polariser arranged on the same side of the spatial light modulator as the display polariser outside the display polariser, the additional polariser being a linear polariser; and
at least one polar control retarder arranged between the display polariser and the additional polariser, the at least one polar control retarder including a switchable liquid crystal retarder comprising a layer of liquid crystal material, and first and second transmissive electrodes on opposite sides of the layer of liquid crystal material, wherein each of the first and second transmissive electrodes is patterned in areas separated by gaps to provide plural addressable regions of the layer of liquid crystal material, at least one of the plural regions being in a shape of a mark for display to an observer.