Patent ID: 8599660

Claim:
An objective lens driving device comprising: an objective lens holder for holding an objective lens; a first tracking coil and a second tracking coil placed on an outer side of a first sidewall portion of the objective lens holder; a third tracking coil and a fourth tracking coil placed on an outer side of a second sidewall portion of the objective lens holder, the second sidewall portion being opposed to the first sidewall portion; an actuator frame for movably supporting the objective lens holder; and a first magnet, a second magnet, a third magnet and a fourth magnet fixed to the actuator frame in order to produce effective magnetic fluxes over effective areas of the first tracking coil, the second tracking coil, the third tracking coil and the fourth tracking coil, respectively, wherein the first tracking coil, the second tracking coil, the third tracking coil and the fourth tracking coil are formed by winding a conducting wire around a first bobbin, a second bobbin, a third bobbin and a fourth bobbin, respectively, the first and second bobbins being sideways projecting parts of the first sidewall portion and the third and fourth bobbins being sideways projecting parts of the second sidewall portion, the first tracking coil and the second tracking coil are tilted to the first sidewall portion, a first protrusion and a second protrusion are provided as projecting parts of the first sidewall portion near the first bobbin and the second bobbin, respectively, and the first tracking coil and the second tracking coil are tilted to the first sidewall portion in such a way that parts of the conducting wires forming the first tracking coil and the second tracking coil are in contact with the first protrusion and the second protrusion, respectively.