Endoscope having optical elements that are resistant to condensation

Claim 1

An endoscope comprising: an insertion section adapted to be inserted within a body cavity of a human subject, and a control section for controlling the operation of the insertion section; a distal end portion for insertion in the body cavity of the human subject, said distal end portion having an illumination window for allowing light from an optical source to be emitted toward the inner wall of the body cavity, and an observation window for receiving the light which has been reflected from the inner wall of the body cavity; light guide means, extending from the insertion section to the control section, for guiding the light from the light source to the illumination window; an eyepiece section located at the control section, to enable the inner wall of the body cavity to be observed from outside of the body cavity; image guide means located within the insertion section, for optically connecting the observation window to the eyepiece; and at least two transparent optical members located between the observation window and the image guide means, said optical members being spaced from one another, said space being filled with a transparent, highly viscous gel-like substance.