Image forming device
US7315422B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 2005 |
| Grant date | Jan 1, 2008 |
| Priority date | — |
| Expiry date | Oct 4, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143507
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming device is provided with: a zoom lens system TL that performs magnification varying by changing the distance between the lens units; and an image sensor SR that converts an optical image formed by the zoom lens system TL into an electric signal. The zoom lens system TL comprises three lens units of negative, positive, positive configuration. The second lens unit Gr2 comprises three single lens elements of, from the object side, a positive lens element L21, a negative meniscus lens element L22 convex to the object side and a positive lens element L23. A condition 1.0<|P22/P21|<2.0 (P21 is the optical power of the object side positive lens element L21 in the second lens unit GR2, and P22 is the optical power of the negative meniscus lens element L22 in the second lens unit GR2) is satisfied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.