Fixed-focus lens
US7423819B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 2008 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Jan 4, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fixed-focus lens including a first lens group, a second lens group, and a third lens group is provided. The first lens group has a negative refractive power, includes a plurality of lenses, and is disposed between an object side and an image side. The lenses of the first lens group include at least one aspheric lens. The second lens group is disposed between the first lens group and the image side and has a positive refractive power. The third lens group is disposed between the second lens group and the image side and has a positive refractive power. The third lens group includes a first triple cemented lens and a second triple cemented lens arranged from the object side to the image side in sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.