Contact image sensor using switchable bragg gratings
US10216061B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2017 |
| Grant date | Feb 26, 2019 |
| Priority date | — |
| Expiry date | Oct 31, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A contact image sensor comprises: a light source providing a collimated beam; a detector and a switchable grating array comprising first and second transparent substrates sandwiching an array of switchable grating elements with transparent electrodes applied to said substrates, said substrates together providing a total internal reflection light guide. A first transmission grating layer overlays said first substrate. A second transmission grating layer overlays said second substrate. A quarter wavelength retarder layer overlays said second transmission grating layer. A platen overlays said quarter wavelength retarder layer; a polarization-rotating reflecting layer overlaying said first transmission grating layer. An input coupler for directing light from said light source into said light guide and an output coupler for extracting light out of said light guide towards said detector are also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.