PROJECTION LENS AND PROJECTOR

WIPO Patent Application WO/2012/057110

A1

This projection lens comprises the five groups of a negative first group, a positive second group, a third group, a fourth group, and a positive fifth group in the given order from the enlargement side. A diaphragm is positioned on the reduction side of the lens most on the reduction side of the fourth group; in the power variation from the tele end to the wide end through an intermediate position that satisfies the conditional formula 0.99 < fm/(ft ×fw)1/2 < 1.01, the position of the first group and the fifth group is fixed, and the combined power constantly moves the positive third group and the fourth group from the enlargement side to the reduction side, satisfying the conditional formulae: 7 <ΔTM3/|ΔTM2|, 7 <ΔTW3/| ΔTW2|, 7 <ΔTM4/|TM2|, 7 <ΔTW4/|TW2|, 0.9 <ΔTM4/ΔTM3 < 1.1, 0.9 <ΔTW4/ΔTW3 < 1.1 (ft, fm, and fw are the whole-system focal distances at the tele end, the intermediate position, and the wide end; ΔTM2-4 are the amounts of motion of the second to fourth groups from the tele end to the intermediate position; and ΔTW2-4 are the amounts of motion of the second to fourth groups from the tele end to the wide end).

JP5727513	Zoom lens and imaging device
JP7020925	Zoom lens and image pickup device with it, image pickup system
JP5609994	Zoom lens, imaging optics and digital equipment

INOUE KAZUHIKO (JP)

PCT/JP2011/074505

May 03, 2012

October 25, 2011

Click for automatic bibliography generation  

KONICA MINOLTA OPTO INC (JP)
INOUE KAZUHIKO (JP)

G02B15/20; G03B21/14

JP2004310083A	2004-11-04
JP2007156268A	2007-06-21
JP2010008797A	2010-01-14

SANO SHIZUO (JP)
Shizuo Sano (JP)

View/Download PDF      PDF Help

Previous Patent: MOBILE STATION DEVICE, PROCESSING METHOD, AND INTEGRATED CIRCUIT

Next Patent: AUTOMATIC ANALYSIS DEVICE