Abstract: A disc loading device for an optical disc drive that discriminates between standard sized optical discs and other objects. In the disc-loading device, two one-degree-of-freedom detecting arms are disposed near the slot of the optical disc drive. An edge sensor including an emitting component and a receiving component is disposed between two detecting arms. A control unit receives data from the detecting arms and the edge sensor when the edge sensor detects the periphery of an object inserted into the optical disc drive. The data is used to calculate the size of the inserted object. By comparing the measured size with the standard sizes of optical discs, the disc loading device can determine whether or not the inserted object is an optical disc or another object. If the control unit determines that the inserted object is not an optical disc, the object is unloaded.