Patent ID: 7649471

Claim:
A logic circuit for controlling display lights of a hard disk, the logic circuit turning on only one display light during a normal operation of the hard disk and turning on only another display light during a failure or rebuilding operation of the hard disk, the logic circuit comprising: a flip-flop electrically coupled to the hard disk and receiving a clock signal, a reset signal and a data signal representing a state of the hard disk, the flip-flop generating an output signal in accordance with the clock signal, the reset signal and the data signal, wherein the clock signal and the reset signal are obtained by a timing process of the data signal; a logic gate electrically coupled to the flip-flop and generating a logic signal in accordance with the data signal and the output signal; and a buffer electrically coupled to the logic gate and receiving the logic signal and an action signal representing the normal operation of the hard disk; wherein the logic signal enables the buffer such that the action signal passes through the buffer to drive a normal light during the normal operation of the hard disk, and the data signal drives a failure light during the failure or rebuilding operation of the hard disk.