Projection lens system with high resolution and compact size
US8254033B2 · kind B2 · utility
3Cited by
1References
12Claims
0Family size
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Key dates
| Filing date | Dec 14, 2010 |
| Grant date | Aug 28, 2012 |
| Priority date | — |
| Expiry date | Apr 3, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/0035
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection lens system includes, from the magnified side to the reduced side thereof, a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having positive refractive power, and a field lens. The projection lens system satisfies the following conditions: 2.9<TT/f<3.7, and 1.85<f4/f<2.65, where TT is a total length of the projection lens system; f is an effective focal length of the projection lens system; f4 is an effective focal length of the field lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.