Moisture-insensitive optical touch sensors
US11775021B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 2021 |
| Grant date | Oct 3, 2023 |
| Priority date | — |
| Expiry date | Aug 17, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04109
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic device may have an optical touch sensor that is insensitive to the presence of moisture. The display may present images through a display cover layer. A light source may illuminate an external object such as a user's finger when the object contacts a surface of the display cover layer. This creates scattered light that may be detected by an array of light sensors. A metasurface grating may be used to couple light from the light source into the display cover layer at an angle such that total internal reflection within the display cover layer is sustained across the display cover layer even when the display cover layer is immersed in water or otherwise exposed to moisture. Additional metasurface gratings may be formed on the display cover layer to redirect light propagating within the display cover layer away from edges that might otherwise defeat total internal reflection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.