| US 7,576,927 B2 | ||
| Zoom lens and electronic imaging apparatus incorporating the same | ||
| Fumikazu Kanetaka, Shibuya-ku (Japan); Toshio Takahashi, Shibuya-ku (Japan); and Tomoyuki Satori, Shibuya-ku (Japan) | ||
| Assigned to Olympus Imaging Corp., Tokyo (Japan) | ||
| Filed on Dec. 07, 2007, as Appl. No. 12/1,262. | ||
| Claims priority of application No. 2006-331772 (JP), filed on Dec. 08, 2006. | ||
| Prior Publication US 2008/0170300 A1, Jul. 17, 2008 | ||
| Int. Cl. G02B 9/34 (2006.01) | ||
| U.S. Cl. 359—774 [359/687; 359/758] | 13 Claims |
| 1. A zoom lens, characterized by comprising, in order from its object side, a positive first lens group, a negative second
lens group, a positive third lens group and a positive fourth lens group, wherein zooming is implemented by changing a space
between adjacent lens groups, said first lens group comprises one positive lens, said second lens group comprises two lenses,
and said fourth lens group comprises one positive lens, with satisfaction of the following conditions:
4<Z<8 (1)
80<νd<98 (2)
where Z is a zoom ratio, and
νd is an Abbe constant of a first lens forming the first lens group.
|