Patent ID: 7663809

Claim:
A compact zoom lens comprising in an order from an object side to an image side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power, wherein the first lens group comprises two lenses, the second lens group comprises three lenses, and the third lens group comprises a single lens, wherein, during zooming from wide angle to telephoto, the distance between the first and second lens groups decreases, the distance between the second and third lens groups increases, and the third lens group moves toward the image side, and wherein the following mathematical inequalities are satisfied: 0.85 < LII f ⁢ ⁢ ω × f ⁢ ⁢ t < 1.0 0.3 < tII f ⁢ ⁢ ω × f ⁢ ⁢ t < 0.4 , 1.5 < fIII f ⁢ ⁢ ω × f ⁢ ⁢ t < 2.0 , where LII indicates the distance the second lens group moves during zooming from a wide-angle position to a telephoto position, tII indicates the thickness of the second lens group from a vertex of the utmost object side of the second lens group to a vertex of the image side of the second lens group, on the optical axis, fIII indicates the overall focal distance of the third lens group, fw indicates the overall focal distance at the wide-angle position, and ft indicates the overall focal distance at the telephoto position.