Patent ID: 7019913

Claim:
A zoom lens barrel, comprising: a first stationary cylinder defining an optical axis, said first stationary cylinder having a guiding cylinder which has a tubular wall surrounding a passage, a guiding and positioning slot being defined in the tubular wall extending along the optical axis, the guiding and positioning slot having a plurality of anchor points and block points alternately arranged on edges thereof; a first lens carrier held in said passage and aligned with said optical axis, said first lens carrier having a driving pole which passes through the guiding and positioning slot and is positioned in one of said anchor points, positions of said first lens carrier being changed by moving the driving pole in the guiding and positioning slot from one of said anchor points to another; a second lens carrier surrounding the guiding cylinder and aligned with said optical axis, said second lens carrier having a retainer and a first guiding slot for the driving pole passing through; a spring, one end of the spring leaning against the first stationary cylinder, the other end leaning against the second lens carrier; and a second stationary cylinder surrounding the second lens carrier, said second stationary cylinder having a stopper and a second guiding slot extending along said optical axis for the driving pole passing through; wherein the spring tends to push the second lens carrier toward a farthest point where the retainer of the second lens carrier engages with the stopper of the second stationary cylinder, and the return of the second lens carrier is driven by the driving pole, which simultaneously compresses the spring.