Patent ID: 7817353

Claim:
A zoom lens barrel assembly in an optical system, which has at least two zoom lens groups arranged on a first optical axis, the zoom lens barrel assembly changing a distance between the lens groups on the first optical axis to adjust a zoom ratio of the optical system, comprising: a zoom motor; a rotary drive member connected to one end of the zoom motor, the rotary drive member acting as a rotary driving source for moving the second zoom lens group according to the zoom ratio; at least one power transmission gear disposed between the zoom motor and the rotary drive member; a second zoom lens group member coupled with the rotary drive member, wherein the second zoom lens group member performs a linear motion along the first optical axis, supports the second zoom lens group arranged along the first optical axis, and has a second guide lug at one position thereof; a first zoom lens group member supporting the first zoom lens group arranged along the first optical axis, the first zoom lens group member having a first guide lug at one position thereof; a cam member having first and second cam slits, the first cam slit receiving the first guide lug, the second cam slit receiving the second guide lug, wherein the cam member receives a driving force from the second zoom lens group through the second cam slit and slides across the first optical axis, thereby transmitting the driving force to the first zoom lens group member through the first cam slit while causing a change in the distance between the first and second zoom lens group members, and at least one of the first and second cam slits is U-shaped; a cam cover disposed outside the cam member; and a frame, with which the cam cover is coupled to prevent the cam member from being released, wherein the zoom motor is placed in front of a reflective optical device on a basis of the first optical axis, and a portion of a rotary shaft of the zoom motor, protruding beyond the rotary shaft, is rotatably inserted into a hole of the frame.