Patent Number: 7,535,650

Title: Zoom lens, image pickup apparatus, and personal digital assistant

Abstract: A zoom lens, in order from an object side, includes a first lens group having a negative refracting power, a second lens group having a positive refracting power and an aperture stop. When zooming from a wide-angle end to a telephoto end, at least the first lens group and the second lens group move, so that an interval between the first lens group and the second lens group can become small and an interval between the second lens group and an image plane can become large. The second lens group has at least three positive lenses and two negative lenses and at least one of the three positive lenses is an aspheric positive lens and an Abbe's number of the glass type: .nu..sub.d and an anomalous dispersion of the glass type: .DELTA..theta..sub.g,F satisfy conditions: .nu..sub.d>80.0 (1) .nu..theta..sub.g,F>0.025 (2).

Inventors: Ohashi; Kazuyasu (Funabashi, JP)

Assignee: Ricoh Company, Ltd.

International Classification: G02B 9/14 (20060101)

Expiration Date: 2021-05-19 0:00:00