Infrared zoom lens assembly having a variable F/number
US5796514A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 1997 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jan 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/4277
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An infrared lens assembly (16) having a variable F/Number. The infrared lens assembly (16) includes a focusing component (33), a collecting component (37), an aperture stop (46), and a diffracting component (41). The focusing component (33) may include a first and a second focusing zoom lens (34, 36) movably mounted in the infrared lens assembly (16). The focusing component (33) and the collecting component (37) may be formed from high dispersion, low index material. The aperture stop (46) may be mounted to the second focusing zoom lens (36) to vary the F/Number between a retracted zoom position and an extended zoom position. The diffracting component (41) may include a diffractive surface to correct color aberrations associated with an infrared waveband. The focusing component (33) and the collecting component (37) cooperate with the diffracting component (41) to focus infrared radiation at an image plane (15) of an infrared detector (18).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.