Fixed-focus lens
US7859763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2010 |
| Grant date | Dec 28, 2010 |
| Priority date | — |
| Expiry date | Feb 12, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fixed-focus lens includes a first, a second, and a third lens groups arranged in sequence from the enlarged side to the reduced side and having positive refractive powers. The first lens group includes a first, a second, and a third lenses from the enlarged side to the reduced side. The second lens group includes a fourth, a fifth, and a sixth lenses from the enlarged side to the reduced side. The third lens group includes a seventh lens. The lens of the first lens group closest to the enlarged side in the fixed-focus lens has a concave surface. The distance between the lens surface of the second lens group closest to the reduced side and the lens surface of the third lens group closest to the enlarged side is L1. The overall length of the fixed-focus lens is L. The fixed-focus lens satisfies 0.1<L1/L<0.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.