Patent ID: 8147404

Claim:
An endoscope shape detecting apparatus comprising: a driving block including a plurality of magnetic-field generating elements and driving signal generating section for generating a magnetic field by supplying a driving signal to the plurality of magnetic-field generating elements; a detecting block for detecting the magnetic field generated by the plurality of magnetic-field generating elements using a plurality of magnetic-field detecting elements; a shape calculating block for calculating a shape of an insertion portion by calculating positions of the plurality of magnetic-field generating elements disposed in the insertion portion of an endoscope or the plurality of magnetic-field detecting elements, based on a frequency component corresponding to a frequency of the driving signal in a detection signal detected by the plurality of magnetic-field detecting elements; a frequency setting section for changeably setting oscillation frequency of a reference clock for deciding the frequency of the driving signal, wherein the reference clock whose oscillation frequency is set by the frequency setting section is supplied both to the driving block and the shape calculating block; and a noise detecting section for detecting a noise level based on the detection signal by the plurality of magnetic-field detecting elements in a state where the driving signal is not applied to each of the plurality of magnetic-field generating elements.