Patent ID: 8480567

Claim:
An endoscope system comprising: a driver that outputs a differential signal; a differential transmission line that transmits the differential signal outputted from the driver; a pulse transformer including, in order to input the differential signal transmitted by the differential transmission line, two input terminals connected to an end of the differential transmission line; an impedance member including a bypass impedance element connected on an input side of the pulse transformer, to which the differential signal is inputted, in parallel to at least the pulse transformer and having, at a predetermined noise frequency of noise mixed in the differential transmission line, impedance smaller than circuit impedance of a circuit to which the pulse transformer, which is connected in parallel to the bypass impedance element, is connected; and a dielectric disposed between the two input terminals of the pulse transformer and between lines of the differential transmission line such that a distance between the two input terminals of the pulse transformer is equal to inter-line impedance of the differential transmission line.