US Patent 7190204 Logical circuit

A logical circuit receives first and second input signals in which a period of a first logic level partially overlaps, and outputs first and second output signals in which a period of the first logic level does not overlap. The logical circuit comprises a first unit which changes a phase of the first output signal from a second logic level to the first logic level when a change of the first input signal from the second logic level to the first logic level is detected. A second unit changes a phase of the second output signal from the first logic level to the second logic level when the second input signal is detected as being at the first logic level at a time of detection of the change of the first input signal.