Patent ID: 6990673

Claim:
A slot-in optical disc drive comprising: a chassis having a slot for receiving an object; two detecting arms rotatably disposed in the chassis in proximity of the slot and adapted to contact and move along the periphery of the object when it is inserted into the slot, the two detecting arms generating first and second position data, respectively; a first edge sensor disposed in the chassis between the two detecting arms for detecting the periphery of the object and generating third position data; a control unit for receiving the first, second and third position data when the first edge sensor detects the periphery of the optical disc, calculating the size of the object according to the first, second, third position data, and a principle of geometry that three points on the periphery of a circle define an arc for calculating its radius; a second edge sensor for detecting the periphery of object and generating a fourth position data, and the control unit receiving the fourth position data, an updated second position and an updated third position data when the second edge sensor detects the periphery of the optical disc, calculating the size of the object according to the fourth, second, third position data, and a principle of geometry that three points on the periphery of a circle define an arc for calculating its radius; and a roller assembly controlled by the control unit for loading and unloading the object; wherein the control unit comparing the size of the object with standard sizes for optical discs, and the control unit controls the roller assembly to continue loading the object when it is standard sized, and controls the roller assembly to unload the object when it is not standard sized.