Three-group zoom lens
US7006300B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2004 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Dec 21, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143507
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens includes three lens groups. The first lens group from the object side has negative refractive power and is formed of two lens components. The second lens group from the object side has positive refractive power and is formed of two lens components. The third lens group is formed of one lens component and has positive refractive power. All but one of the lens components may be lens elements. Only the first and second lens groups move along the optical axis for zooming. At least one lens surface of the second lens group has portions with curvatures of different signs. The zoom lens may include as many as five other aspheric surfaces. The aspheric lenses are made of plastic. The zoom lens may be formed of only the three lens groups and satisfies specified conditions to assure that the zoom lens is compact and favorably corrects various aberrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.