Patent ID: 9557541
Date: 2017-01-31
CPC Classifications: G02B

Claim:
1. A zoom lens system comprising, sequentially from an object side to an image side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power, wherein the first lens group comprises one negative lens, the second lens group comprises one positive lens, the third lens group comprises a positive lens, the fourth lens group comprises at least one positive lens, and a first condition, 0.03<|f wherein f wherein the first lens group comprises the one negative lens and three first group positive lenses sequentially from the object side to the image side, the second lens group comprises at least three second group negative lenses and the one positive lens, the third lens group comprises the positive lens and a third group cemented lens comprising a third group positive lens and a third group negative lens sequentially provided from the object side to the image side, the fourth lens group comprises the at least one positive lens and at least one negative lens, and wherein a zoom ratio of the zoom lens system is greater than 28.