Multi-focus system for a low light level vision apparatus
US5175651A · kind A · utility
17Cited by
12References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1991 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Mar 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A night vision apparatus 10 includes a first focusing refracting lens 28 which focuses light rays 29 from distant scene 14 onto a light intensifier 30. The kinoform 40 or bifringent lens 78 are disposed in the light path to allow light rays 35 from near scene 18, 20, 22 and 24 to be focused onto light intensifier 30 to form a multi-focus night vision apparatus with increased depth of focus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.