Patent ID: 11892718
Assignee: REALD SPARK, LLC
Field: Optics (Instruments)
Classification: CPC G  B | IPC F  G

Claim 0:
1. A display device comprising:
a spatial light modulator arranged to output spatially modulated light;
a display polariser arranged on a side of the spatial light modulator, the display polariser being a linear polariser; and
a view angle control arrangement comprising:
an additional polariser arranged on the same side of the spatial light modulator as the display polariser, the additional polariser being a linear polariser; and
at least one polar control retarder and a polarisation-switch retarder arranged between the display polariser and the additional polariser,

wherein
the polarisation-switch retarder is switchable between a first mode in which the polarisation-switch retarder is arranged to output a first polarisation state and a second mode in which the polarisation-switch retarder is arranged to output a second polarisation state orthogonal to the first polarisation state, and
the view angle control arrangement and display polariser have a profile of transmission by angle having a local minimum in a first direction in the first mode and a local minimum in a second direction in the second mode.