Directional display apparatus
US11442316B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 2021 |
| Grant date | Sep 13, 2022 |
| Priority date | — |
| Expiry date | May 7, 2041 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S40/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A switchable privacy display for an automotive vehicle comprises a spatial light modulator, a first switchable liquid crystal retarder and first passive retarder arranged between a first pair of polarisers and a second switchable liquid crystal retarder and second passive retarder arranged between a second pair of polarisers. The first switchable liquid crystal retarder comprises a homeotropic alignment layer and a homogeneous alignment layer. The second switchable liquid crystal retarder comprises two homeotropic alignment layers or two homogeneous alignment layers. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss to the passenger, whereas off-axis light has reduced luminance to reduce the visibility of the display to off-axis driver leaning towards the display. In a shared mode of operation, the liquid crystal layers are controlled so that off-axis luminance and reflectivity are unmodified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.