JP4017727B2 - The tip of the perspective endoscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distal end portion of a perspective endoscope in which a distal end surface of a distal end portion main body is formed obliquely.
[0002]
[Prior art]
In a perspective endoscope in which the observation optical axis is directed obliquely forward with respect to the axial direction of the distal end main body, generally, the distal end surface of the distal end main body provided at the distal end of the insertion portion is the axis of the distal end main body. The observation window and the illumination window are arranged side by side on the slope.
[0003]
[Problems to be solved by the invention]
The perspective type endoscope can easily observe a portion that is difficult to observe with any of the front-view type and side-view type endoscopes, and is useful depending on the application.
[0004]
However, the perspective endoscope has a drawback that, when inserted into a body cavity, when an obliquely formed distal end surface approaches the mucosal surface, halation occurs on the observation screen and it is difficult to observe.
[0005]
As schematically shown in FIG. 5, when the mucosal surface 100 is in close proximity to the portion opposite to the observation window 92 when viewed from the illumination window 91, the illumination window 91 shining gently is reflected on the mucosal surface. It becomes a secondary point light source 200, and it is considered that the light from the point light source 200 enters the observation screen 93 and causes the halation 300 as shown in FIG.
[0006]
In view of the above, an object of the present invention is to provide a distal end portion of a perspective endoscope in which halation is unlikely to occur during observation inside a body cavity and a good observation image can be obtained.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the distal end portion of the perspective endoscope according to the present invention is formed such that the distal end surface of the distal end main body provided at the distal end of the insertion portion is inclined with respect to the axial direction of the distal end main body. In the perspective endoscope in which the observation window and the illumination window are arranged side by side on the slope, the slope of the slope is formed in the vicinity of the illumination window and on the opposite side of the observation window from the illumination window. Protrusions protruding forward from the surface are provided.
[0008]
A tip cap made of an electrically insulating material surrounding the outer periphery of the tip portion main body may be provided, and the protrusion may be formed by locally projecting the tip cap from the surface of the slope.
[0009]
Further, it is preferable that the protrusion protrudes from the surface of the slope by a height of 0.5 to 3 mm, more preferably 1 to 2 mm, and an antireflection treatment is applied to at least the surface of the protrusion facing the illumination window. It should be given.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
3 is a plan view of the distal end portion of the insertion portion of the endoscope, FIG. 1 is a sectional view taken along line II, and FIG. 2 is a sectional view taken along line II-II.
[0011]
A distal end body 1 made of, for example, stainless steel is connected to the distal end of the bending portion 2 that is formed to be freely bent by remote operation and is provided at the distal end portion of the flexible tube. A tip cap 3 made of an electrically insulating plastic material is joined.
[0012]
The distal end surface of the distal end main body 1 is formed, for example, on a slope 5 that is inclined 45 ° obliquely upward. An observation window 6 and an illumination window 7 are arranged adjacent to each other in the lower half of the slope 5 and are nozzles for selectively ejecting air and water toward the surface of the observation window 6. 8 is arranged above the observation window 6. 9 is an air / water supply tube.
[0013]
An objective optical system 12 including a prism 11 is arranged inside the observation window 6, and an object image 45 ° above the front oblique direction, which is a direction perpendicular to the inclined surface 5, is embedded in the tip body 1. An image is formed on the imaging surface of the imaging device 13 by the objective optical system 12, converted into an electronic signal by the solid-state imaging device 13, and transmitted outside the insertion portion. Note that an optical endoscope using an image guide fiber instead of the solid-state imaging device 13 may be used.
[0014]
An exit end portion of the illumination light guide fiber bundle 14 is disposed inside the illumination window 7, and illumination light emitted from the illumination light guide fiber bundle 14 passes through the illumination window 7 and is irradiated to the subject. The
[0015]
In a groove 15 formed above the illumination window 7, a treatment instrument raising base 17 for changing the protruding direction of the distal end portion of the treatment instrument inserted into the treatment instrument insertion channel 16 is provided by a remote operation on a support shaft 18. It is stored so as to rotate around the center.
[0016]
The tip end surface of the tip cap 3 is entirely formed on the same surface as the inclined surface 5 of the tip end body 1. However, a protrusion 20 that protrudes from the surface of the slope 5 by, for example, 1 to 2 mm is formed on a portion of the distal end surface of the distal end cap 3 that is located on the side opposite to the observation window 6 when viewed from the illumination window 7.
[0017]
Therefore, even when the mucosal surface is in close proximity to the inclined surface 5 in the body cavity, the mucosal surface abuts on the protrusion 20 and does not approach the inclined surface 5 at a position opposite to the observation window 6 when viewed from the illumination window 7. Therefore, the illumination window 7 is not reflected at a position causing halation, and a good endoscopic observation image can be obtained.
[0018]
Therefore, it is desirable that at least the surface of the projection 20 on the side facing the illumination window 7 be subjected to some antireflection treatment such as matte black processing or satin processing.
[0019]
Further, if the height of the projection 20 with respect to the surface of the slope 5 is too low, an anti-halation effect cannot be obtained. Conversely, if the height is too high, the insertion of the endoscope is hindered. The thickness is desirably in the range of about 0.5 to 3 mm.
[0020]
Note that the protrusion 20 needs to be provided on a portion located on the side opposite to the observation window 6 when viewed from the illumination window 7, but the protrusion 20 is extended to the lower portion of the illumination window 7 as shown in FIG. May be provided. However, it is not preferable to provide the observation window 6 in the vicinity of the observation window 6 because it is difficult to remove water droplets from the surface of the observation window 6 and the image quality of the observation is deteriorated.
[0021]
【The invention's effect】
According to the present invention, by providing a projection that protrudes forward from the surface of the slope in the vicinity of the illumination window provided on the slope of the tip body and on the opposite side of the observation window from the illumination window. In that position, the mucosal surface abuts on the projection and cannot approach the slope any further, so that a reflected image of the illumination window cannot be formed at the position causing halation, and a good observation image without halation can be obtained. it can.
[Brief description of the drawings]
FIG. 1 is a side cross-sectional view taken along line II of a distal end portion of a perspective endoscope according to a first embodiment of the present invention.
FIG. 2 is a side cross-sectional view taken along the line II-II of the distal end portion of the perspective endoscope according to the first embodiment of the present invention.
FIG. 3 is a plan view of the distal end portion of the perspective endoscope according to the first embodiment of the present invention.
FIG. 4 is a side sectional view of a distal end portion of a perspective endoscope according to a second embodiment of the present invention.
FIG. 5 is a schematic view showing a usage state of a conventional perspective endoscope.
FIG. 6 is a schematic diagram showing an observation screen of a conventional perspective endoscope.
[Explanation of symbols]
1 Tip Body 3 Tip Cap 5 Slope 6 Observation Window 7 Illumination Window 20 Projection

Claims (4)

A perspective endoscope in which the distal end surface of the distal end main body provided at the distal end of the insertion portion is formed obliquely with respect to the axial direction of the distal end main body, and an observation window and an illumination window are arranged side by side on the inclined surface In
Protrusion projecting forward from the surface of the slope is provided in the vicinity of the illumination window and on the opposite side of the observation window from the illumination window, and at least the surface of the projection facing the illumination window A distal end portion of a perspective endoscope, characterized in that an antireflection treatment is applied to the endoscope. 2. A perspective mold according to claim 1, further comprising a tip cap made of an electrically insulating material surrounding an outer periphery of the tip portion main body, wherein the protrusion is formed by locally projecting the tip cap from the surface of the slope. End of the endoscope. The distal end portion of the perspective endoscope according to claim 1 or 2, wherein the projection protrudes from the surface of the slope by a height of 0.5 to 3 mm. The distal end portion of the perspective endoscope according to claim 3, wherein the protrusion protrudes from the surface of the inclined surface by a height of 1 to 2 mm.

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