Patent ID: 8564711
Filing Date: 2013-10-22
Classification: G02B,H04N

Abstract:
1. A zoom lens comprising: a first lens group of positive refractive power; a second lens group of negative refractive power; a third lens group of positive refractive power; and a fourth lens group of negative refractive power, and a fifth lens group of positive refractive power arranged in the above-mentioned order from the object side to the image side; wherein, at activation of variable power from the wide angle end to the telescopic end, the first lens group moves so as to get closer to the object side at the telescopic end than at the wide angle end; the third lens group moves so as to get closer to the image side at the telescopic end than at the wide angle end, the forth lens group moves so as to get closer to the object side at the telescopic end than at the wide angle end; and the fifth lens group moves so as to get closer to the image side at the telescopic end than at the wide angle end at activation of variable power from the wide angle end to the telescopic end; and further, at activation of variable power from the wide angle end to the telescopic end, a gap between the first lens group and the second lens group increases; a gap between the second lens group and the third lens group decreases; a gap between the third lens group and the forth lens group increases; and a gap between the forth lens group and the fifth lens group increases; and the conditional formulas (1B), (2B) and (3B) below are satisfied: where ft is focal length at the telescopic end: