Zoom lens device and optical apparatus provided with the same
US6606200B1 · kind B1 · utility
32Cited by
40References
104Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1999 |
| Grant date | Aug 12, 2003 |
| Priority date | — |
| Expiry date | Oct 19, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/145121
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens device including a diffraction optical element constructed in a new way. In a basic form of the invention, the zoom lens device includes in order of lens units from a long conjugate side, at least a first lens unit including the diffraction optical element, a second lens unit which is moved during zooming in order to change the size of an image, and a third lens unit. In this zoom lens device, during zooming at least one of the lens units from the third lens unit onwards is moved in order to correct a change in an image plane which occurs as the magnification changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.