The image processor (20) includes a display oscillation circuit (206) that generates a display clock, and a monitor synchronization signal generating part (207) that generates a monitor display synchronization signal based on the display clock. The endoscope (10) includes an imaging oscillation circuit (111) that generates an imaging clock, pixels (115) that are driven based on the imaging clock, converts optical information into electrical signals and outputs the electrical signals as a digital data of a serial form, and a phase comparator (113) that compare the phase of the monitor display synchronization signal with the imaging clock, and control the oscillation of the imaging oscillation circuit (111).
