Lens driving unit and image photographing module comprising the same

An image photographing module comprising:

• a lens unit supporting at least one lens,
• wherein the lens unit is movable along an optical axis of light of a subject image, and has a guide hole guiding the movement of the lens unit;
• a module supporting unit disposed at the back of the lens unit along the optical axis,
• wherein a driving axis that is movably inserted into the guide hole is coupled to the module supporting unit;
• a shutter unit that controls the amount of light incident on the lens unit and is disposed in front of the lens unit along the optical axis such that the shutter unit is substantially included within the overall perimeter of the lens unit along a plane parallel to the optical axis;
• a lens driving unit that is disposed substantially within the shutter unit or the lens unit when viewed along a plane perpendicular to the optical axis, and coupled to the lens unit within the perimeter of the lens unit along a plane parallel to the optical axis, and includes a curved vibration piezoelectric motor that moves the lens unit along the optical axis using friction with the driving axis;
• a ball guide disposed between the driving axis and the guide hole to reduce friction between the driving axis and the guide hole;
• wherein the ball guide comprises a curved plate and a plurality of balls and
• a coil spring pressing on a single point of the curved vibration piezoelectric motor toward the lens unit and the module supporting unit, the single point being proximate to the driving axis.