Zoom mechanism of imaging lens module

A zoom mechanism of imaging lens module, comprising:

• a first lens carrier adapted to fix a lens unit which defines an optical axis, said the first lens carrier having a first cam follower;
• a second lens carrier adapted to fix a lens unit which is coaxial with said optical axis, the second lens carrier having a second cam follower;
• a rotary cylinder having a tubular wall surrounding a passage for holding the first lens carrier and the second lens carrier, the rotary cylinder being coaxial with said optical axis, the rotary cylinder having at least a portion cut out to define a first cam rim and a second cam rim, each cam rim having a guiding rim, a beginning rim and an end rim, wherein the beginning rim and the end rim are formed perpendicular to said optical axis and are arranged to space a certain distance therebetween in circumferential direction and axial direction respectively, the guiding rim connects the beginning rim and the end rim;
• at least one spring urging the first cam follower of the first lens carrier and the second cam follower of the second lens carrier to lean against the first cam rim and the second cam rim respectively;
• a guiding means guiding the first lens carrier and the second lens carrier moving along said optical axis;
• a stationary cylinder having a tubular wall surrounding a passage for holding the rotary cylinder, the stationary cylinder defining a leading slot extending in circumferential direction and radial direction;
• and
• a stem fixed to the rotary cylinder and passing through the leading slot.