Noise suppression device for an endoscope

摘要

The noise suppression device is used in an endoscope which operates with a solid-state pick-up element and eliminates external noise which is superimposed in an unwanted manner on the internal image signal which is obtained from the solid-state pick-up element when the signal is transmitted to the imaging unit. The output of the solid-state pick-up element is amplified by a preamplifier and forwarded via a signal transmission device. This signal transmission device consists of two shielded cables and supplies the internal image signal to a differential amplifier via at least one of the cables. This differential amplifier operates in such a manner that the in-phase component is eliminated, as a result of which the external noise, which is induced with the same phase in the shielded cables, is cancelled.