Endoscope having a nozzle element for cleaning a lens element
An endoscope with a distal housing element which has a lens element, and with a nozzle element for cleaning the surface of the lens element. The lens element is a curved lens element, the curvature of which protrudes from the housing element in a distal direction. The nozzle element is arranged at the distal side of the distal housing element adjacent to the curved lens element. The nozzle element has a distal nozzle opening in the form of an elongated medium outlet slit directed toward the curved lens element.
1 . An endoscope comprising
a distal housing element having a lens element, and
a nozzle element for cleaning the surface of the lens element;
wherein
the lens element has a convex distalmost lens surface which protrudes from the housing element in a distal direction,
the nozzle element is arranged at a distal side of the distal housing element adjacent to the lens element,
the nozzle element has a distal nozzle opening in the form of an elongated medium outlet slit, directed toward the lens element such that a flow exiting from the nozzle element flows over a side of the distalmost lens surface facing away from the nozzle element,
the distalmost lens surface extends distally beyond the nozzle element, and
the nozzle element is inclined such that the flow exits toward the distal direction.
2 . The endoscope according to claim 1 , wherein
the elongated medium outlet slit extends transverse to an extension direction of the endoscope.
3 . The endoscope according to claim 1 , wherein
the lens element has an area (Fü) to be flowed over, which is formed at least by an entire exposed lens surface,
the distal nozzle opening has a nozzle opening area (Fd),
wherein 30<Fü/Fd<40.
4 . The endoscope according to claim 1 , wherein
the distal nozzle opening has a width which is smaller than a width of the lens element at a proximal edge of the lens element.
5 . The endoscope according to claim 1 , wherein
the distal nozzle opening is aligned with respect to the lens element such that a flow exiting from the distal nozzle opening is directed tangential ±10° with respect to a proximal edge of the lens element.
6 . The endoscope according to claim 5 , wherein
the flow exiting from the distal nozzle opening is directed with respect to the proximal edge of the lens element at an angle of −10°<Ltgü<+20°, wherein
Ltgü is the tangent to the lens surface of the lens element at the proximal edge of the lens element,
a positive angle extends away from the lens element at the proximal edge of the lens element, and
a negative angle extends into the lens element at the proximal edge of the lens element.
7 . The endoscope according to claim 1 , wherein
the distal nozzle opening is arranged proximal to a proximal edge of the lens element.
8 . The endoscope according to claim 1 , wherein
the distal nozzle opening is arranged spaced apart from a proximal edge of the lens element by a distance,
the distance is less than or equal to half a width of the lens element at the proximal edge of the lens element.
9 . The endoscope according to claim 1 , wherein
a curvature of the lens element is spherical or aspherical.
10 . The endoscope according to claim 1 , wherein
the distal nozzle opening forms a single distal opening of the nozzle element.
11 . The endoscope according to claim 1 , wherein
the lens element comprises an area to be flowed over, which is formed by an entire exposed distalmost lens surface, and
the area to be flowed over is greater than a quarter of a cross-sectional area of the endoscope at the distal housing element.
12 . The endoscope according to claim 1 , wherein
the elongated medium outlet slit, has a width (bd) and a height (hd), wherein hd<bd.
13 . The endoscope according to claim 1 , wherein
the elongated medium outlet slit has a width (bd) and a height (hd), wherein hd<1 mm<bd.
14 . The endoscope according to claim 1 , wherein the flow exiting from the nozzle element flows over the side of the distalmost lens surface facing away from the nozzle element due to surface tension.
15 . The endoscope according to claim 1 , wherein the lens element has a spherical curvature and is one of a fish-eye lens or a wide-angle lens.
16 . The endoscope according to claim 1 , wherein an overflow velocity ΔV Ü of the flow exiting from the nozzle element behaves in such a way that the difference in the overflow velocity ΔV Ü =V ümax −V ümin is at most 20% of an average overflow velocity.
17 . The endoscope according to claim 1 , wherein:
the nozzle element has a side wall which is open on a side facing the lens element,
the side wall is covered by a nozzle cover,
a rim of the nozzle cover facing the lens element forms a straight distal boundary of the nozzle opening,
lateral sides of the nozzle opening are each bounded by a portion of the side wall,
a proximal boundary of the nozzle opening is formed by the distal side of the distal housing element, and
the proximal boundary of the nozzle opening is concavely curved toward the distal side.