Patent ID: 8491467

Claim:
An endoscope comprising: an insertion section which is configured to be inserted in a body cavity; a distal end section body comprising a distal end section of the insertion section and has at least an observation window at a flat surface of a distal end surface; a first flow path positioned and configured to communicate with a first fluid source so as to supply liquid and has an opening end open to a more outer peripheral side than the observation window on the flat surface of the distal end surface; a second flow path positioned and configured to communicate with a second fluid source so as to supply air and has an opening end open to a more outer peripheral side than the observation window on the flat surface of the distal end surface apart from the opening end of the first flow path; and a nozzle formed in an arcuate shape along an outer peripheral portion of the distal end surface to form a spatial communication between the first flow path and the second flow path so that the liquid supplied from the first flow path and the air supplied from the second flow path are mixed at an area above the arcuate shaped nozzle to yield a mixture fluid, the nozzle having a jet outlet configured to jet out the mixture fluid, passing across the observation window, wherein the jet outlet of the nozzle is disposed offset on the arcuate shaped nozzle formed by the first flow path and the second flow path, the offset from a center equally distant from the opening end of the first flow path and the opening end of the second flow path being closer to the opening end of the second flow path, and the jet outlet of the nozzle is formed in a linearly tapered shape such that an outer opening area of the jet outlet toward the observation window is smaller than an opening area at the spatial communication area.