A processor includes: a data transmission/reception section that reads parameter data unique to a scope from a ROM provided in the scope; a register communication state determination section that determines whether or not the parameter data read from the data transmission/reception section has an error; and a mute control/color bar control section that if a result of the determination by the register communication state determination section indicates that the parameter data has an error, controls an image processing section according to a type of the parameter data having the error.