Disk loading device for disk player and a method for using the same

A disk loading for loading either a first or second, smaller, disk. The disk loading device comprises a main chassis, a power transmission unit, a slider, a first and second linkage mechanism, a sub-chassis, and a locking lever. The first linkage mechanism guides the first disk to a chucking position while being pushed and moved by the first disk, and moves the slider in connection with the power transmission unit when the first disk is being introduced. The second linkage mechanism connects the slider to the power transmission unit while being pushed and moved by the second disk when the second disk is moved to the chucking position. The sub-chassis is linked to a guide unit which separates the first linkage mechanism from the first disk or the second disk placed on the chucking position. The locking lever selectively locks the movement of the first linkage mechanism or releasing the locking of the first linkage mechanism.