Optical device designed for the introduction of a collimated image into an observer's visual field and enbaling night vision
US5157548A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1991 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Jul 22, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0156
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The disclosure relates to optical devices enabling daytime vision and night vision of an external scene with, in both cases, the superimposed introduction, into an observer's visual field, of an image given by an image generator. The image given by the light intensifier of a night observation system is processed in the same way as the image given by the image generator, by an auxiliary image-combining optical system which mixes these two images before they reach the main image-combining optical system of the device through which, in night vision, the observer directly sees the external scene. The auxiliary image-combining optical system is designed so that, in night vision, at least the greatest part of the light coming from the image generator reaches the main image-combining optical system. Depending on the embodiment, this result is obtained either with a retractable semi-reflecting mirror or with a semi-reflecting surface selective in frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.