Zoom lens and imaging apparatus
US7623299B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2004 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | Sep 12, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/145121
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens is provided, which includes a first lens group Gr1 having positive refractive power, a second lens group Gr2 having negative refractive power, which is movable in an optical axis direction mainly for zooming (varying power), a third lens group Gr3 having positive refractive power, a fourth lens group Gr4 having negative refractive power, which is movable in the optical axis direction for correcting fluctuations in focal position during zooming and for focusing, and a fifth lens group Gr5 having positive refractive power, which lens groups are arrayed in order from an object side, wherein the first lens group includes a concave lens, a convex lens, and a triple-cemented lens T1 in which a lens L6 made of special low-dispersion glass is sandwiched in the middle, which lenses are arrayed in order from the object side. Thereby, a range from a super wide-angle area to a super telephoto area can be covered with angles of view of not less than 67 degrees at a wide-angle end and not more than 1.6 degrees at a telephoto end, various aberrations can be favorably corrected while providing a zoom ratio of about 40 times, and a zoom lens excellent in mass productivity can be attaine…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.