A method for scanning a track of a disc-shaped storage medium comprises the steps of: receiving at least one scanning command; calculating energy consumption estimates at different scanning mode settings ; determining a scanning mode setting associated with minimal expected energy consumption; executing said at least one scanning command at the thus determined scanning mode setting. The lamp cup is a two-piece structure; a power driver is further disposed in the power connecting part. The base station may include an impedance matching circuit configured to match an impedance of the power line of the structure, and a receiver coupled to the impedance matching circuit. Since the side and upper surfaces of each fuse element are covered with the silicon nitride film of the same thickness, the film covering the fuse elements has no local weak point. This allows the light delivery pattern or field of view or both to be aggressively steered off-axis to achieve significant increased performance levels. After being notified of exceptions, business partners may provide corrected information or new information to resolve the exceptions.