Invention Grant
US08395847B2 Zoom lens 有权
变焦镜头

Zoom lens
Abstract:
A zoom lens includes sequentially from an object side a first lens group having a negative refractive power; a diaphragm; and a second lens group having a positive refractive power. Zoom from a wide angle edge to a telephoto edge is performed by displacement of the second lens group along an optical axis, toward the object side. Correction of imaging plane variation accompanying the zoom, is performed by displacement of the first lens group along the optical axis. The second lens group includes sequentially from the object side, a positive first lens having at least on aspheric surface and a positive second lens. Furthermore, a first condition υd21>63 and a second condition υd22>70 are satisfied, υd21 being the Abbe number for a d-line in the first lens of the second lens group and υd22 being the Abbe number for a d-line in the second lens of the second lens group.
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