US 12,353,073 B2
Anti-peeping system, optical laminate, display device, and anti-peeping method
Yuji Toyota, Ibaraki (JP)
Assigned to NITTO DENKO CORPORATION, Ibaraki (JP)
Appl. No. 17/915,710
Filed by NITTO DENKO CORPORATION, Ibaraki (JP)
PCT Filed Mar. 26, 2021, PCT No. PCT/JP2021/013052
§ 371(c)(1), (2) Date Sep. 29, 2022,
PCT Pub. No. WO2021/200723, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-064553 (JP), filed on Mar. 31, 2020.
Prior Publication US 2023/0131221 A1, Apr. 27, 2023
Int. Cl. G02F 1/13 (2006.01); G02F 1/1335 (2006.01); G02F 1/13363 (2006.01)
CPC G02F 1/1323 (2013.01) [G02F 1/133531 (2021.01); G02F 1/133638 (2021.01)] 16 Claims
OG exemplary drawing
 
1. A peeking prevention system comprising:
a display device having a display plane from which to emit polarized light;
a partition to delimit from surroundings a space in which displaying is to be provided by the display device, the partition having a light-transmitting portion through which the inside of the space is viewable; and
an optical stack opposed to the display plane of the display device, wherein,
the light-transmitting portion includes a transparent substrate and a first polarizing layer, the first polarizing layer having a first absorption axis that is parallel to a first direction;
the optical stack includes
a second polarizing layer having a second absorption axis that is parallel to a second direction, the second direction being orthogonal to the first direction, and
a first phase difference layer disposed at a side of the second polarizing layer facing the display plane; and
the first phase difference layer has an in-plane retardation of 4000 nm or more, and
wherein the second polarizing layer and the first phase difference layer are attached together via a first adhesion layer.