Fixed-focus lens
US9470874B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2015 |
| Grant date | Oct 18, 2016 |
| Priority date | — |
| Expiry date | Oct 7, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fixed-focus lens including a first lens group, a second lens group and an aperture stop is provided. The first lens group has a positive refractive power, and includes a first lens, a second lens and a third lens arranged in sequence from a magnified side to a reduced side. The second lens group has a positive refractive power, and includes a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from the magnified side to the reduced side. A product of a refractive power and a slope of a refractive index changing with a temperature change of any one lens of the second lens group is P×(dn/dt), and a sum of P×(dn/dt) of the lenses of the second lens group is less than 0. The aperture stop is disposed between the first lens group and the second lens group.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.