Patent ID: 8824064
Filing Date: 2014-09-02
Classification: G02B

Abstract:
1. A zoom lens comprising: a fixing barrel; a cam barrel rotatably received in the fixing barrel; a guiding barrel movably received in the fixing barrel and partially receiving the cam barrel, the guiding barrel being moveable along an optical axis of the zoom lens following the motion of the cam barrel; a first lens group received in the guiding barrel; a second lens group rotatably received in the cam barrel, the first and second lens groups moving along the optical axis of the zoom lens when the cam barrel rotates around the optical axis of the zoom lens in the fixing barrel; a third lens group aligned with the first and second lens groups, and movably received in the fixing barrel and moveable along the optical axis of the zoom lens; and a bracket; wherein the fixing barrel comprises an inner surface which defines three cam barrel guiding recesses, each of the cam barrel guiding recesses is angled from the optical axis of the zoom lens, the cam barrel comprises three first cam pins projecting outwards at evenly intervals on an outer sidewall of the first lens barrel near a rear end of the cam barrel, each of the cam pins engages with a corresponding cam barrel guiding recess of the fixing barrel and slides along the corresponding cam barrel guiding recess when the cam barrel is rotated relative to the fixing barrel, the fixing barrel comprises a first barrel guiding slot, a second barrel guiding slot, and a third barrel guiding slot in its inner surface, the first barrel guiding slot, the second barrel guiding slot, and the third barrel guiding slot are parallel to the optical axis of the zoom lens, the guiding barrel comprises an outer sidewall, an inner sidewall opposite to the inner sidewall, a first sliding pin received in the first barrel guiding slot, a second sliding pin received in the second barrel guiding slot, and a third sliding pin received in the third barrel guiding slot, all of the first, second and third sliding pins respectively extend outwards from an end of the outer sidewall, the guiding barrel is capable of sliding along the optical axis of the zoom lens with respect to the fixing barrel by the first sliding pin, the second sliding pin, and the third sliding pin respectively sliding in the first barrel guiding slot, the second barrel guiding slot, and the third barrel guiding slot, the second lens group comprises a second lens barrel and a second lens received in the second lens barrel, the second lens barrel comprises three third cam pins and three fourth cam pins, each the third and fourth cam pins projects outwards from an outer sidewall of the second lens barrel, the cam barrel defines three second cam grooves and three third cam grooves in its inner sidewall, the cam barrel comprises a front end opposite to the rear end, the second cam grooves and the third cam grooves extend from the rear end to the front end and are angled from the optical axis of the zoom lens, the second cam grooves receive the third cam pin, the third cam grooves receive the fourth cam pin, when the cam barrel is rotated related relative to the fixing barrel, the third cam pins slide in a corresponding second cam groove and the fourth cam pins slide in a corresponding third cam groove, the bracket comprises an annular bottom plate, three bulging portions, three locating plates, three first latching plates and a guiding column, the three bulging portions are perpendicularly extended downwards from the bottom plate in a direction parallel to the optical axis of the zoom lens, the three locating plates are projected outwards from an outer sidewall of the bottom plate in radical directions of the bracket, the guiding column extends from the outer sidewall of the bottom plate in a radical direction of the bracket and is positioned between two neighboring locating plates, the second lens barrel defines three indentions in its outer sidewall in a direction parallel to the optical axis of the zoom lens, each of the bulging portions is received in a corresponding indention, each of the three first latching plates extends outwards from a corresponding locating plate, the fixing barrel also defines a fourth barrel guiding slot, and a fifth barrel guiding slot, the three first latching plates are respectively engaged with the first barrel guiding slot, the third barrel guiding slot, and the fifth barrel guiding slot, and the guiding column is engaged with the second barrel guiding slot.