Image pickup system for an endoscope using a first filter matched to a frequency of a fiber array and a second matched to a frequency of an image pickup device

摘要

An image pickup system for endoscopes includes an image guide fiber bundle, a light guide fiber bundle, an imaging lens unit having optical low-pass filters, and a solid-state image pickup device. Further, a first optical low-pass filter having a spatial frequency response depending on an array of fibers of the image guide fiber bundle and a second low-pass filter having a spatial frequency response depending on a sampling frequency of the solid-state image pickup device can also be provided between the image guide fiber bundle and the solid-state image pickup device. Thus, even in the image guide fiber bundle which is different in effective diameter and core diameter and has a disorderly array of fibers, the generation of moiré can be prevented without reducing resolution.