A lens barrel is disclosed. The lens barrel includes a sleeve having curved groove on an inner side thereof, a lens module having at least one lens and an optical axis having an object end and an image end, and a pin projecting from the lens module and engaged in a curved groove, whereby the lens module is slidably disposed in the sleeve and the sleeve is rotated to move the lens module along the optical axis. The pin has a contact surface contacting the curved groove and a notch is formed on the contact surface.
1. A lens barrel, comprising:
a sleeve having a curved groove on an inner side thereof;
a lens module having at least one lens and an optical axis having an object end and an image end;
a pin projecting from the lens module and engaging the curved groove, whereby the lens module is slidably disposed in the sleeve and the sleeve is rotated to move the lens module along the optical axis, wherein the pin has a contact surface contacting the curved groove and a notch is formed on the contact surface; and
a positioning plane is formed on the contact surface;
wherein the notch is formed on the image end and the positioning plane is formed on the object end.
2. The lens barrel as claimed in claim 1 , wherein the notch comprises a first plane and a second plane adjacent to the first plane, and the first and second planes are adjacent to the contact surface.
3. The lens barrel as claimed in claim 2 , wherein the first plane is parallel to the pin.
4. The lens barrel as claimed in claim 3 , wherein the second plane is parallel to the pin.
5. The lens barrel as claimed in claim 2 , wherein the first plane has a predetermined angle with respect to the pin.
6. The lens barrel as claimed in claim 1 , wherein the pin is tapered, the contact surface is conical, and the curved groove has a tapered cross section corresponding to the contour of the pin.
7. The lens barrel as claimed in claim 1 , wherein the pin is perpendicular to the optical axis.
8. The lens barrel as claimed in claim 1 , wherein the notch is formed on the image end.
9. The lens barrel as claimed in claim 1 , wherein the notch is formed on the object end.
10. A lens barrel, comprising:
a sleeve having a curved groove on an inner side thereof;
a lens module having at least one lens and an optical axis having an object end and an image end;
a pin projecting from the lens module and engaging the curved groove, whereby the lens module is slidably disposed in the sleeve and the sleeve is rotated to move the lens module along the optical axis, wherein the pin has a contact surface contacting the curved groove and a notch is formed on the contact surface; and
a positioning plane is formed on the contact surface;
wherein the notch is formed on the object end and the positioning plane is formed on the image end.