Optical system of collimation notably for helmet display unit
US5453877A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1989 |
| Grant date | Sep 26, 1995 |
| Priority date | — |
| Expiry date | Oct 19, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/017
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The system is designed to be mounted in a air pilot's helmet. It uses a confocal assembly with a first parabolic mirror and a second parabolic mirror, placed downline of a collimation objective which gives a collimated radiation. The first mirror is totally reflective and the second mirror is semi-transparent to simultaneously transmit, by reflection, the collimated radiation and, by transparency, for example the view of the external landscape. These two mirrors are integrated into the ends of a plate with two parallel faces. The collimated radiation penetrates the plate by one of the parallel faces, gets reflected on the first mirror, undergoes a succession of total reflections on the parallel faces and then gets reflected on the second mirror before leaving the plate, still doing so through one of the two faces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.