Patent ID: 7457060

Claim:
A lens driving device comprising: a lens barrel comprising a lens holder for holding at least one lens therein and an extension part extended from the lens holder; a piezoelectric vibrator providing a driving power necessary for driving the lens barrel, the piezoelectric vibrator comprising a piezoelectric body for being flexed and bent in response to applying the driving power, and a friction member disposed at a leading end of the piezoelectric body in contact with the extension part, to move the lens barrel in a bending direction of the piezoelectric body; a preload member providing resilient force that compresses the piezoelectric vibrator against the extension part, the preload member having a free end thereof in resilient contact with a rear end of the piezoelectric body to maintain contact between the extension part of the lens barrel and the friction member of the piezoelectric vibrator; and a guiding part for guiding movement of the lens barrel in an optical axis direction, the guiding part including a first guide rod having a predetermined length disposed vertically in a first guide groove formed in a portion of the extension part to be movable on a bearing member having upper and lower ball pairs in point contacts with outer surfaces of the first guide groove and outer surfaces of the first guide rod and a retainer having a plurality of upper and lower ball grooves in which the upper and lower balls are rotatably disposed, and a second guide rod having a predetermined length disposed vertically in a second guide groove formed in another portion of the extension part.