Privacy display apparatus
US11109014B2 · kind B2 · utility
2Cited by
52References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 5, 2018 |
| Grant date | Aug 31, 2021 |
| Priority date | — |
| Expiry date | Nov 5, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2013/403
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A privacy display comprises a liquid crystal spatial light modulator, a switchable retarder and a passive compensation retarder arranged between a pair of polarisers. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without change of image contrast, whereas off-axis light has reduced contrast to reduce the visibility of the display to off-axis snoopers over a wide polar angular range. In a wide angle mode of operation, the retardance of the switchable retarder is adjusted so that off-axis contrast is substantially unmodified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.