BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and features of the present invention will be clearly understood from the following detailed description when reading with reference to the accompanying drawings wherein:
FIG. 1 is a schematic view of a rigid endoscope system equipped with an observation window cleaning device according to an embodiment of the present invention;
FIG. 2 is a conceptual view of the a rigid endoscope;
FIG. 3 is a perspective view of a pressure pumping type liquid container with a coupling unit attached thereto; and
FIG. 4 is a conceptual view of the coupling unit attached to the pressure pumping type liquid container.