Reflective optical stack for privacy display
US10303030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2018 |
| Grant date | May 28, 2019 |
| Priority date | — |
| Expiry date | Jul 18, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10K59/50
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A privacy display comprises a polarized output spatial light modulator, reflective polarizer, switchable liquid crystal retarder and polarizer. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. Further, display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction and increased frontal reflectivity to ambient light. In a wide angle mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.