A synchronous signal conversion circuit converts a first synchronous signal, which is transmitted with a data signal, to a second synchronous signal conforming to a predetermined standard. In the synchronous signal conversion circuit, a transition detection circuit detects transition of the first synchronous signal. A synchronous signal generation circuit generates a second synchronous signal in response to a detection result by the transition detection circuit. An output timing control circuit delays the second synchronous signal generated by the synchronous signal generation circuit so that the second synchronous signal synchronizes with the data signal.