System and method for using a linear polarizer to reduce optical crosstalk for optical proximity sensors
US9528820B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2012 |
| Grant date | Dec 27, 2016 |
| Priority date | — |
| Expiry date | Sep 30, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/94108
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical proximity sensor often emits light, and detects the photons in the returned light signal. Because light can be reflected and scattered by cover glass and ink layer printed on the cover glass, optical crosstalk is a concern for the optical proximity sensors. In one embodiment, the present disclosure provides an optical proximity sensor including a linear polarizer to cover the photo detector, or a polarizer to cover the light emitting device, or two polarizers to cover both the photo detector and the light emitting device. The polarizer blocks the s-polarized light and only allows the p-polarized light to pass through. Because the scattered light is predominated by the s-polarization, the optical crosstalk may be reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.