Macro lens
US7009779B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2004 |
| Grant date | Mar 7, 2006 |
| Priority date | — |
| Expiry date | Jan 13, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A macro lens comprised of a front lens group of a retrofocus type and a rear lens group of which component lenses are aligned in the order from the closest to the subject. The front lens group includes a first lens of a negative meniscus lens having its convex surface projecting toward the object, a second lens of a positive lens having its one surface with greater curvature oriented toward the object, a third lens of a positive lens having its one surface with greater curvature oriented toward the object, a fourth lens of a negative lens having its concave surface with greater curvature oriented toward the imaging plane, fifth and sixth lenses of a junction lens in combination of a negative lens with a positive lens, the negative lens having its one surface with greater curvature oriented toward the object, across a space having an aperture stop, and a seventh lens of a positive lens having its one surface with greater curvature oriented toward the imaging plane, the rear lens group including an eighth negative lens and a ninth positive lens, the macro lens providing relations expressed as follows:1.0<|F1|/Ft<1.3 (1)4.0<|Fr|/Ft<6.0 (2)where F1 is a focal length of the first lens…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.