Wide angle zoom lens and image pickup device using the same

• Main Authors: Yamada, Yasuharu, Hosoya, Takeshi
• Format: Patent
• Language: English
• Published: 28.06.2011

ffwffwA wide angle zoom lens, includes, from an object side in the following order: a first lens group that has a negative refractive power; a second lens group that has a positive refractive power; and a third lens group. When variable magnification is carried out from a wide angle end to a telephoto end, the first and second lens groups move while the third lens group remains fixed, so that an air space between the first lens group and the second lens group becomes narrow and that a space between the second lens group and the third lens group becomes wide. The first and second lens groups each include at least one positive lens and one negative lens. The third lens group includes one positive or negative meniscus lens whose convex surface faces an image surface. The following conditional expressions (1) and (2) are satisfied: 1.4≦|1|/≦1.8  (1); and 1.7≦2/≦2.1  (2) where f1 is a focal length of the first lens group of the wide angle zoom lens; f2 is a focal length of the second lens group of the wide angle zoom lens; and fw is a focal length of the entire system at the wide angle end of the wide angle zoom lens.