Endoscope having an extension guide for observation

Claim 1

An endoscope comprising: an elongated rigid sheath to be introduced in the body cavity, said sheath having a distal end and a base end, a control section housing having a side wall and a pair of end walls, said base end of the sheath being attached to one of the end walls, an extension guide having an open end fixed to the control section housing to communicate with the interior of the housing and an outer free end into which an eyepiece is fitted, said guide being flexible along its length such that it may be bent into a plurality of angular orientations with respect to said housing, and a single optical fiber bundle of an observation system made of many thin glass fibers and having a distal end inserted within the sheath and a base end portion extended into the extension guide through said housing and said open end of the extension guide, said base end portion of the fiber bundle having a mounting base end fixed to the extension guide in a position near to the eyepiece and directly optically connected to the eyepiece without interposing a prism therebetween, said base end portion of said fiber bundle having a flexibility except for the mounting base end and the glass fibers of the remaining portion of the fiber bundle being united together in a rigid glass rod-like fashion.