US 12,253,748 B2
Switchable privacy display
Jonathan Harrold, Leamington Spa (GB); Michael G Robinson, Boulder, CO (US); Graham J. Woodgate, Henley-on-Thames (GB); Robert Ramsey, Boulder, CO (US); and Ben Ihas, Boulder, CO (US)
Assigned to RealD Spark, LLC, Boulder, CO (US)
Filed by RealD Spark, LLC, Boulder, CO (US)
Filed on May 1, 2024, as Appl. No. 18/652,672.
Application 18/652,672 is a continuation of application No. 18/643,255, filed on Apr. 23, 2024.
Claims priority of provisional application 63/461,885, filed on Apr. 25, 2023.
Prior Publication US 2024/0361626 A1, Oct. 31, 2024
Int. Cl. G02F 1/13 (2006.01); G02F 1/133 (2006.01); G02F 1/1335 (2006.01); G02F 1/1343 (2006.01)
CPC G02F 1/1323 (2013.01) [G02F 1/13306 (2013.01); G02F 1/133528 (2013.01); G02F 1/13439 (2013.01)] 30 Claims
OG exemplary drawing
 
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;
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;
a switchable diffractive view angle control retarder arrangement arranged between the additional polariser and the display polariser, the switchable diffractive view angle control retarder arrangement comprising a switchable diffractive liquid crystal retarder comprising a layer of liquid crystal material and a transmissive electrode arrangement arranged to drive the layer of liquid crystal material,
wherein the transmissive electrode arrangement is patterned to be capable of driving the layer of liquid crystal material selectively into:
a narrow-angle state in which the layer of liquid crystal material has a structure of orientations which: causes the layer of liquid crystal material to introduce net phase shifts to light having a predetermined polarisation state that are uniform across an area of the layer of liquid crystal material and thereby cause the layer of liquid crystal material to provide no diffractive effect to the light having the predetermined polarisation state; and causes the switchable diffractive view angle control retarder arrangement to introduce net relative phase shifts to orthogonal polarisation components of the light having the predetermined polarisation state that differ along a viewing axis and an inclined axis that is inclined to the viewing axis; and
a wide-angle state in which the layer of liquid crystal material has a structure of orientations which causes the layer of liquid crystal material to introduce net phase shifts to the light having the predetermined polarisation state that vary spatially across the area of the layer of liquid crystal material and thereby cause the layer of liquid crystal material to provide a diffractive effect to the light having the predetermined polarisation state.