US 11,921,367 B2
Marks for privacy display
Jonathan Harrold, Upper Heyford (GB); Graham J. Woodgate, Henley-on-Thames (GB); Michael G. Robinson, Boulder, CO (US); Robert A. Ramsey, Boulder, CO (US); and Ben Ihas, Boulder, CO (US)
Assigned to RealD Spark, LLC, Boulder, CO (US)
Filed by RealD Spark, LLC, Beverly Hills, CA (US)
Filed on Oct. 13, 2022, as Appl. No. 17/965,344.
Application 17/965,344 is a continuation of application No. 17/954,225, filed on Sep. 27, 2022.
Claims priority of provisional application 63/250,580, filed on Sep. 30, 2021.
Prior Publication US 2023/0116008 A1, Apr. 13, 2023
Int. Cl. G02F 1/1343 (2006.01); G02F 1/01 (2006.01); G02F 1/13 (2006.01); G02F 1/1333 (2006.01); G02F 1/1335 (2006.01); G02F 1/1337 (2006.01); G02F 1/1347 (2006.01); G09G 3/34 (2006.01); G09G 3/36 (2006.01)
CPC G02F 1/1323 (2013.01) [G02F 1/0136 (2013.01); G02F 1/133374 (2021.01); G02F 1/133536 (2013.01); G02F 1/133618 (2021.01); G02F 1/1337 (2013.01); G02F 1/134309 (2013.01); G02F 1/134318 (2021.01); G02F 1/134327 (2013.01); G02F 1/13439 (2013.01); G02F 1/13471 (2013.01); G09G 3/3406 (2013.01); G09G 3/36 (2013.01); G09G 2310/0297 (2013.01); G09G 2320/068 (2013.01); G09G 2330/021 (2013.01); G09G 2358/00 (2013.01); G09G 2360/16 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A display device for use in ambient illumination comprising:
a spatial light modulator arranged to output light, wherein the spatial light modulator comprises an output polariser arranged on an output side of the spatial light modulator, the output polariser being a linear polariser;
a view angle control arrangement comprising:
an additional polariser arranged on an output side of the output polariser, the additional polariser being a linear polariser;
a reflective polariser arranged between the output polariser and the additional polariser, the reflective polariser being a linear polariser; and
at least one polar control retarder arranged between the reflective 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 at least one 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; and
a control system arranged to control the spatial light modulator and to apply voltages across the first and second transmissive electrodes for driving the layer of liquid crystal material,
wherein the control system is arranged to be operable in plural modes of operation, including:
a wide-angle operational display mode, in which the control system controls the spatial light modulator to display an operational image and applies voltages across the first and second transmissive electrodes that drive the layer of liquid crystal material into a same state in different regions such that the operational image is visible at a wide angle and a narrow angle, and the mark is not visible at the narrow angle or the wide angle;
at least one narrow-angle operational display mode, in which the control system controls the spatial light modulator to display an operational image and applies voltages across the first and second transmissive electrodes that drive the layer of liquid crystal material into states in different regions such that the operational image is visible at the narrow angle but not at the wide angle, and the mark is not visible at the narrow angle; and
at least one mark display mode in which the control system applies voltages across the first and second transmissive electrodes that drive the layer of liquid crystal material into different states in different regions such that the mark is visible, wherein the at least one mark display mode includes a mark display mode in which the control system controls the spatial light modulator to display no image and applies voltages across the first and second transmissive electrodes that drive the layer of liquid crystal material into different states in different regions such that the mark is visible at the wide angle but not at the narrow angle.