Patent ID: 7151637
Filing Date: 2006-12-19
Classification: G02B

Abstract:
1. A zoom lens system comprising, in order from an object side to an image plane side thereof, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, wherein: all spaces between the lens groups are varied while changing magnification, and wherein, the second lens group comprises only four lenses, these four lenses consist of, in order from the object side, a first negative lens, a second negative lens, a third negative lens, and a fourth positive lens, the third lens group comprises only four lenses, these four lenses consist of, in order from the object side, a first positive lens, a second positive lens, a third negative lens, and a fourth positive lens.