Patent Publication Number: US-2007112249-A1

Title: Endoscope

Description:
CROSS REFERENCE TO RELATED APPLICATION  
      This application is a continuation application of PCT/JP2005/013571 filed on Jul. 25, 2005 and claims the benefit of Japanese Applications No. 2004-216355 filed in Japan on Jul. 23, 2004, and No. 2004-216356 filed in Japan on Jul. 23, 2004, the entire contents of each of which are incorporated herein by their reference. 
    
    
     BACKDROUND OF THE INVENTION  
      1. Filed of the Invention  
      The present invention relates to an endoscope including an instrument swing table provided at a distal end of an endoscope inserting portion configured to swinging an instrument inserted into an instrument insertion channel provided to the inserting portion and a swing table mechanism configured to remotely operate the instrument swing table from an operating portion.  
      2. Description of the Related Art  
      In recent years, it is widely recognized that a technique of removing an affected region in a body cavity while observing the affected region with an endoscope is useful. The endoscope used for the technique of removing an affected region in endoscope observation is proposed by U.S. Pat. No. 6,458,074 and Japanese Patent Laid-Open No. 2003-204930 for instance.  
      The endoscope proposed by U.S. Pat. No. 6,458,074 is provided with a first forceps raising mechanism configured to raise an instrument in a first direction at a distal end opening of a first instrument insertion channel opened at a distal end of an inserting portion and a second forceps raising mechanism configured to raise an instrument in a second direction different from the first forceps raising mechanism at the distal end opening of a second instrument insertion channel opened at the distal end of the inserting portion. The raising directions of the two forceps raising mechanisms are different directions in at least two combinations. To be more specific, the endoscope allows the instrument which is the forceps used for the technique of removing an affected region to be projected, raised or swung in two different directions from the distal end of the inserting portion under observation by the endoscope.  
      The endoscope proposed by Japanese Patent Laid-Open No. 2003-204930 includes an instrument swing table operating mechanism configured to remotely operate an instrument swing table which is the forceps raising mechanism configured to control the raising direction of the instrument provided at the distal end opening of the instrument insertion channel opened at the distal end of the inserting portion proposed by U.S. Pat. No. 6,458,074 in both directions by using two operating wires. The instrument swing table operating mechanism can remotely operate and control the projection, raising or swinging directions of the instrument projected from the distal end of the inserting portion of the endoscope according to the above-mentioned U.S. Pat. No. 6,458,074 by using two operating wires.  
      Thus, an instrument swing table operating function is the function of raising or swinging the instrument projected from the distal end of the inserting portion in a predetermined direction, where it pulls the two operating wires provided on the instrument swing table for the sake of remotely operating rasing and swinging of the instrument swing table.  
      As for the structure of pulling the operating wires, a rotating operation of a swing table operating knob provided on a user&#39;s side of the operating wires is performed (rotational motion), and the rotational movement of the swing table operating knob is converted to linear motion so as to pull the operating wires.  
     SUMMARY OF THE INVENTION  
      A first endoscope of the present invention is the one comprising: observation means provided at a distal end of an endoscope inserting portion; an instrument insertion channel provided to the endoscope inserting portion; an instrument swing table configured to swing an instrument inserted into the instrument insertion channel and led out of the distal end of the endoscope inserting portion; a swing table operating portion configured to operate the instrument swing table on a user&#39;s side; and a control mechanism configured to control swinging of the instrument swing table so that, when operating the swing table operating portion at a constant speed, a swinging speed in the case where the distal end of the instrument led out of the distal end of the endoscope inserting portion is at a center of a screen of an endoscope image obtained by the observation means is faster than the swinging speed in the case where the distal end of the instrument is in a peripheral part of the screen of the endoscope image.  
      A second endoscope is the one comprising: an instrument insertion channel provided to the endoscope inserting portion; an observation optical system including an observation window provided at a distal end of an endoscope inserting portion; an instrument swing table configured to swing an instrument led out of the distal end via the instrument insertion channel in an approximately horizontal direction or an approximately vertical direction of a screen of an endoscope image picked up by the observation optical system; and an instrument swing table operating portion configured to operate the instrument swing table on a user&#39;s side, wherein, if the swing table operating portion is operated at a constant speed, the distal end of the instrument led out of the distal end moves faster in the case where the distal end of the instrument is at a center of the endoscope image than in the case where the distal end of the instrument is in a peripheral part of the endoscope image. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view showing an overall configuration of an endoscope according to a first embodiment of the present invention;  
       FIG. 2  is a plan view showing a configuration of a distal end of an endoscope inserting portion of the endoscope according to the first embodiment of the present invention;  
       FIG. 3  is a perspective view showing the distal end of the endoscope inserting portion according to the first embodiment of the present invention;  
       FIG. 4  is a plan view showing a distal end component except a front face of an electric insulating cover of the distal end of the endoscope inserting portion according to the first embodiment of the present invention;  
       FIG. 5  is a perspective view showing the configuration of a first instrument swing table provided at the distal end of the endoscope inserting portion according to the first embodiment of the present invention;  
       FIG. 6  is a sectional view showing a cross-section cut at a VI to VI line of  FIG. 1  of the distal end of the endoscope inserting portion for the sake of describing operation according to the first embodiment of the present invention;  
       FIG. 7  is a sectional view showing a relation between a first instrument swing table and an instrument provided at the distal end of the endoscope inserting portion, which is cut at a VII to VII line of  FIG. 2  according to the first embodiment of the present invention;  
       FIG. 8  is a sectional view showing the cross-section of the endoscope inserting portion for the sake of describing the operation as with  FIG. 7  according to the first embodiment of the present invention;  
       FIG. 9  is a sectional view showing an internal configuration of a first swing table operating portion provided to an endoscope operating portion according to the first embodiment of the present invention;  
       FIG. 10  is a plan view viewed from an F direction of  FIG. 9  and showing the internal configuration of the first swing table operating portion provided to the endoscope operating portion according to the first embodiment of the present invention;  
       FIG. 11  is a plan view viewed from a G direction of  FIG. 9  and showing the internal configuration of the first swing table operating portion provided to the endoscope operating portion according to the first embodiment of the present invention;  
       FIG. 12  is a plan view showing a state of having rotationally driven from the state of  FIG. 11  and shows the internal configuration of the first swing table operating portion provided to the endoscope operating portion according to the first embodiment of the present invention;  
       FIG. 13  is an explanatory diagram for describing an operational state of the endoscope according to the first embodiment of the present invention;  
       FIG. 14  is an explanatory diagram for describing a swinging state of the instrument in an endoscope image of the endoscope according to the first embodiment of the present invention;  
       FIG. 15  is an explanatory diagram for describing a swinging operation of the instrument in the endoscope image according to the first embodiment of the present invention;  
       FIG. 16  is an explanatory diagram for describing a cleaning state by the endoscope inserting portion in the endoscope image according to the first embodiment of the present invention;  
       FIG. 17  is a sectional view showing the cleaning state of the distal end of the endoscope inserting portion according to the first embodiment of the present invention;  
       FIG. 18  is a sectional view showing the configuration of the first instrument swing table operating portion of the endoscope according to a second embodiment of the present invention;  
       FIG. 19  is an explanatory diagram for describing an action on an endoscope image screen of the instrument operated-by the first instrument swing table operating portion of the endoscope according to the second embodiment of the present invention;  
       FIG. 20  is a plan view showing the configuration of a distal end face of the distal end of the endoscope inserting portion according to a third embodiment of the present invention;  
       FIG. 21  is a sectional view cut at a section line XXI to XXI of  FIG. 20  and showing the configuration of the distal end of the endoscope inserting portion according to the third embodiment of the present invention;  
       FIG. 22  is an explanatory diagram for describing the screen of the endoscope image observed by the endoscope according to the third embodiment of the present invention;  
       FIG. 23  is a plan view showing the configuration of the distal end of the endoscope according to a fourth embodiment of the present invention;  
       FIG. 24  is a sectional view showing the configuration of the distal end of the endoscope, which is cut at a section line XXIV to XXIV shown in  FIG. 23  according to the fourth embodiment of the present invention;  
       FIG. 25  is a sectional view showing the configuration of the distal end of the endoscope, which is cut at a section line XXV to XXV shown in  FIG. 23  according to the fourth embodiment of the present invention;  
       FIG. 26  is a sectional view for describing a detergent action of the distal end of the endoscope according to the fourth embodiment of the present invention;  
       FIG. 27  is a plan view showing the configuration of the distal end of the endoscope according to a fifth embodiment of the present invention;  
       FIG. 28  is an explanatory diagram for describing the swinging operation of the instrument in the endoscope image of the endoscope according to the fifth embodiment of the present invention; and  
       FIG. 29  is an explanatory diagram for describing an operation of the endoscope according to the fifth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Hereunder, embodiments of the present invention will be described in detail with reference to the drawings. A first embodiment of an endoscope of the present invention will be described by using FIGS.  1  to  16 .  
       FIG. 1  is a perspective view showing an overall configuration of an endoscope according to the present invention.  FIG. 2  is a plan view showing a configuration of a distal end of an endoscope inserting portion of the endoscope.  FIG. 3  is a perspective view showing the distal end of the endoscope inserting portion.  FIG. 4  is a plan view showing a distal end component except a front face of an electric insulating cover of the distal end of the endoscope inserting portion.  FIG. 5  is a perspective view showing the configuration of a first instrument swing table provided at the distal end of the endoscope inserting portion.  FIG. 6  is a sectional view showing a cross-section cut at a VI to VI line of  FIG. 1  of the distal end of the endoscope inserting portion for the sake of describing operation.  FIG. 7  is a sectional view showing a relation between a first instrument swing table and an instrument provided at the distal end of the endoscope inserting portion, which is cut at a VII to VII line of  FIG. 2 .  FIG. 8  is a sectional view showing the cross-section of the endoscope inserting portion for the sake of describing the operation as with  FIG. 7 .  FIG. 9  is a sectional view showing an internal configuration of a first swing table operating portion provided to an endoscope operating portion.  FIG. 10  is a plan view viewed from an F direction of  FIG. 9  and showing the internal configuration of the first swing table operating portion provided to the endoscope operating portion.  FIG. 11  is a plan view viewed from a G direction of  FIG. 9  and showing the internal configuration of the first swing table operating portion provided to the endoscope operating portion.  FIG. 12  is a plan view showing a state of having rotationally driven from the state of  FIG. 11  and shows the internal configuration of the first swing table operating portion provided to the endoscope operating portion.  FIG. 13  is an explanatory diagram for describing an operational state of the endoscope. FIG.  14  is an explanatory diagram for describing a swinging state of the instrument in an endoscope image of the endoscope.  FIG. 15  is an explanatory diagram for describing a swinging operation of the instrument in the endoscope image.  FIG. 16  is an explanatory diagram for describing a cleaning state by the endoscope inserting portion in the endoscope image.  FIG. 17  is a sectional view showing the cleaning state of the distal end of the endoscope inserting portion.  
      First, the overall configuration of the endoscope according to the present invention will be described by using  FIG. 1 . An endoscope  1  according to the present invention mainly comprises an inserting portion  2 , an operating portion  3  provided at a base end of the inserting portion  2  and a universal cord  4  having a light guide and the like connected to the operating portion  3  inserted therein.  
      The inserting portion  2  comprises a flexible tube portion  12  formed by a slender flexible member, a bending portion  14  bending vertically and horizontally and the distal end  5  in order from the base end. The distal end  5  includes a distal end component  51  which is provided with observation means  6 , two illumination windows  7 ,  7 , an air and water nozzle  8  for supplying air and water to the observation means  6 , a front water supply port  9 , a first instrument swing table  10  and a second instrument swing table  11 .  
      The inserting portion  2  is provided with a first instrument insertion channel  15  (refer to  FIG. 2 ) and a second instrument insertion channel  16  (refer to  FIG. 2 ) therein though not shown in  FIG. 1 . A tip of the first instrument insertion channel  15  opens at the first instrument swing table  10  provided on the distal end  5 , and a rear end thereof is communicated with a first opening  17  provided on the operating portion  3 . The tip of the second instrument insertion channel  16  opens at the second instrument swing table  11  provided on the distal end  5 , and the rear end thereof is communicated with a second opening  18  provided on the operating portion  3 .  
      The operating portion  3  incorporates a first swing table operating knob  21  configured to remotely operate the first instrument swing table  10  provided on the base side of the inserting portion  2 , a first swing table operating portion  19  containing a first instrument swing table operating mechanism  20  (refer to  FIG. 9 ) described later configured to swing the first instrument swing table  10  on operating the first swing table operating knob  21 , the first opening  17  and second opening  18  placed as close as possible to the first swing table operating portion  19  and provided on the upside of the first swing table operating portion  19  in the drawing, a gripper  50  provided on the upside of the first opening  17  and second opening  18  in the drawing for an operator to grip the operating portion  3  and a second swing table operating function not shown provided on the upside of the gripper  50  in the drawing configured to remotely operate the second instrument swing table  11 , where a second swing table operating knob  45  as a part of the second swing table operating function is provided outside.  
      Outside the operating portion  3  where the second swing table operating knob  45  is provided, there are an air and water supply control button  46 , a suctioning control button  47 , an image recording button  48 , a bending operating knob  49  and the like. The second swing table operating knob  45  is operated by a left thumb of the operator gripping the gripper  50 , and the first swing table operating knob  21  is provided on the same surface side where the bending operating knob  49  is provided.  
      The first swing table operating knob  21  is provided as close as possible to the first opening  17  on the same surface side where the bending operating knob  49  is provided. The first swing table operating knob  21  is normally operated by a right hand. To be more specific, as for the endoscope  1 , the air and water supply control button  46 , the suctioning control button  47 , the image recording button  48  and the bending operating knob  49  are operated while operating the second swing table operating knob  21  configured to remotely operate the second instrument swing table  11  by gripping the gripper  50  of the operating portion  3  by a left hand LH of the operator (refer to  FIG. 16 ). A right hand RH of the operator performs a forward/backward movement operation of a first instrument  54  and a second instrument  56  inserted through the first instrument insertion channel  15  and the second instrument insertion channel  16  from the first opening  17  and the second opening  18 , an operation of the first swing table operating knob  21  and forward/backward movement and twisting operations of the inserting portion  2 .  
      The configuration of a distal end face of the distal end  5  of the endoscope  1  will be described by using  FIG. 2 . As previously described, the distal end face of the distal end  5  is provided with the observation means  6  approximately at the center of the front face, the two illumination windows  7  placed sandwiching the observation means  6 , the air and water nozzle  8  configured to supply air and water to the observation means  6 , a front water supply port  9  configured to supply water to the front from the distal end  5 , the first instrument swing table  10  and the second instrument swing table  11 .  
      The observation means  6  of the present embodiment comprises an observation optical system and a solid-state image sensing device placed at a focal position of the observation optical system. An arrow P direction in the drawing is an upward direction of a screen of an endoscope image displayed on a monitor not shown based on an image pickup signal of an observed region of which image was picked up by the solid-state image sensing device.  
      The first instrument swing table  10  is communicated with the first instrument insertion channel  15  and horizontally swung in the drawing by two operating wires  32   a ,  32   b . The second instrument swing table  11  is communicated with the second instrument insertion channel  16  and vertically swung in the drawing by one operating wire  32   c . The first instrument swing table  10  is housed in the opening provided only on the front face of the distal end face of the distal end  5  while the second instrument swing table  11  is housed in the opening provided on the front face to a side face of the distal end face of the distal end  5 .  
      The opening on the side face of the distal end  5  is opened in a minimum size not to interfere with a swinging instrument or the second instrument swing table  11 . The first instrument swing table  10  is provided with a first instrument inserting portion  40  configured to insert the instrument inserted from the first instrument insertion channel  15 . The second instrument swing table  11  also has the instrument inserting portion configured to insert the instrument inserted from the second instrument insertion channel  16  formed thereon.  
      The distal end  5  is rigidly formed by a metallic member. An external surface of the distal end  5  is almost entirely covered by an electric insulating cover  52  formed by an electric insulating member. The electric insulating cover  52  is formed in a shape partially swollen outside so as not to contact the first instrument swing table  10  when swinging.  
      Furthermore, the observation means  6  and the first instrument swing table  10  are placed so that a center line Q equally dividing the field of view of the observation means  6  into the right and left and a rotation axis R of the first instrument swing table  10  approximately match horizontally when viewed from the front of the distal end  5 .  
      A fluid delivery passage  9   a  configured to deliver a fluid in an observation direction in front of the distal end  5  is placed on the right side of the first instrument swing table  10  in the drawing and below the second instrument swing table  11  in the drawing. As shown in  FIG. 3 , a delivery direction of the fluid delivery passage  9   a  is approximately parallel with a horizontal swinging direction of the first instrument swing table  10  in the drawing when viewed from the front of the distal end  5 , which is formed to be directed to the center line Q equally dividing the field of view of the observation means  6  into the right and the left.  
      To give a detailed description as to a vertical relation between the opening position of the fluid delivery passage  9   a  and the first instrument swing table  10  in a perpendicular direction in the drawing in particular as against the swinging direction by using  FIGS. 1 and 3 , an opening width  11  of the fluid delivery passage  9   a  in an approximately perpendicular direction to the swinging direction of the first instrument swing table  10  is placed within a width of a vertical swinging range of the instrument when the instrument projected from the first instrument swing table  10  is horizontally swung, that is within a vertical width  12  of the first instrument inserting portion  40  of the first instrument swing table  10 .  
      The delivery direction of the fluid delivery passage  9   a  is set up to pass inside an instrument swinging area indicated by oblique lines in the drawing on horizontally swinging the instrument projected from the first instrument inserting portion  40  of the first instrument swing table  10  so as to be a water supply direction line S 1  which is directed to the center line Q equally dividing an observation field of view of the observation means  6  into the right and left. To be more specific, when viewed from the front of the distal end  5 , the water supply direction line S 1  from the fluid delivery passage  9   a  has its delivery direction set up to be within projected area (shaded area in the drawing) on which the instrument swinging area is projected in front from the distal end face of the distal end  5 .  
      A dashed line G in the drawing in  FIG. 2  indicates the shape of a first channel opening  53  described later when viewed from the front, which is an oval shape longer in a horizontal direction than in a vertical direction.  
      Next, a description will be given by using  FIG. 4  as to housing the first instrument swing table  10  and the second instrument swing table  11  into the distal end component  51  of the distal end  5 .  
       FIG. 4  is a plan view showing a state of removing the electric insulating cover  52  covering the front face of the distal end component  51  shown in  FIG. 2 .  
      The distal end component  51  is provided with a first storage room  28  configured to house the first instrument swing table  10  and a second storage room  29  configured to house the second instrument swing table  11 . The first storage room  28  and the second storage room  29  are coupled in a C portion close to the fluid delivery passage  9   a  in the drawing. The first storage room  28  and the second storage room  29  are coupled in the C portion to facilitate cleaning of the first and second instrument swing tables  10 ,  11  by a cleaning method described later.  
      The configuration of the first instrument swing table  10  will be described by using  FIG. 4 . The first instrument swing table  10  is inserted into a member formed in an overall shape being approximately columnar or elliptic-cylindrical or in the shape of a rectangular column having its one side formed as an arc from the first opening  17  of the operating portion  3  so as to form the first instrument inserting portion  40  from which the instrument inserted into the first instrument insertion channel  15  is led out.  
      A rotation axis hole  42  in which a rotation axis not shown is to be mounted is formed at the center of an undersurface  41  of the first instrument swing table  10 . The undersurface  41  and a top surface  43  of the first instrument swing table  10  have notched faces which are notched in mutually different directions formed thereon. One of the notched faces has a wire terminal member  44   a  of the operating wire  32   a  rotatably mounted thereon while the other notched face has a wire terminal member  44   b  of the operating wire  32   b  rotatably mounted thereon. To be more specific, the two operating wires  32   a ,  32   b  are pulled so that the first instrument swing table  10  can rotate from left to right or right to left in the drawing in reference to the rotation axis hole  42 .  
      The second instrument swing table  11  has approximately the same configuration as that of the first instrument swing table  10 , which can be rotated vertically in the drawing by the operating wire  32   c .  
      Here, a description will be given by using  FIG. 6  as to the relation between the second instrument swing table  11  and the instrument inserted into the second instrument insertion channel  16 .  FIG. 6  is a sectional view cut at a VI to VI line of  FIG. 1  and viewed from the arrow direction in the drawing.  
      The second instrument swing table  11  is rotatably mounted in proximity to the tip of a second channel opening  55   a  to which the second instrument insertion channel  16  is connected. At the center of the second instrument swing table  11 , a second instrument inserting portion  58  into which the second instrument  56  is to be inserted is formed. The second instrument  56  inserted into the second instrument inserting portion  58  and projected into a body cavity from the distal end face of the distal end  5  swings vertically to the range indicated by a two-dot chain line in the drawing by remotely controlling the operating wire  32   c . An amount of projection U of the second instrument  56  from the distal end face of the distal end  5  of the second instrument  56  is a distance suitable for observability and processability of an affected region, such as 15 to 25 mm. The vertical swinging of the distal end of the second instrument  56  should not exceed a vertical observation field of view range Y of the observation means  6 .  
      A setup is made so that the distal end of the second instrument  56  does not reach a height of the horizontal swinging of the first instrument  54  when the second instrument swing table  11  is completely inversed. To be more specific, it is set up in a positional relation in which the first instrument  54  does not contact the second instrument  56  even if the first instrument  54  is horizontally swung by the first instrument swing table  10  in the state of having the second instrument swing table  11  completely inversed and having the second instrument  56  projected straight in an axial direction of the distal end  5 .  
      Next, a description will be given by using  FIGS. 7 and 8  as to the relation between the first instrument swing table  10  and the instrument inserted into the first instrument insertion channel  15 .  FIGS. 7 and 8  are sectional views cut at a section line VII to VII shown in  FIG. 2 .  
      The first instrument swing table  10  is provided to the first channel opening  53  connected to the distal end of the first instrument insertion channel  15  which is communicated with the first opening  17  of the operating portion  3  and contained in the flexible tube portion  12 , the bending portion  14  and to the distal end  5 , and it is rotatably mounted by mounting the rotation axis not shown in the rotation axis hole  42 .  
      The first instrument  54  inserted from the first opening  17  and inserted into the first instrument insertion channel  15  and the first channel opening  53  is led out to the affected region in the body cavity located in front of the distal end  5  via the instrument inserting portion  40  of the first instrument swing table  10 . If the operating wires  32   a ,  32   b  of the first instrument swing table  10  having led out the first instrument  54  are pulled by the remote operation, the first instrument  54  horizontally swings in the range indicated by the two-dot chain line in the drawing.  
      As for the horizontal swinging range of the first instrument swing table  10 , however, the distal end of the first instrument  54  being swung should not exceed a field of view range F of the observation optical system of the observation means  6 . As will be described in detail later in the description of the configuration and action of the first swing table operating portion  19  of the operating portion  3 , the swinging of the first instrument swing table  10  is set up so that, when the first swing table operating knob  21  is operated at an even rotation speed, the swinging speed of the distal end of the first instrument  54  is faster in the case where the distal end of the first instrument  54  is at the center of the field of view range of the observation optical system than in the case where it is in both the peripheral parts of the field of view range of the observation optical system.  
      Next, a description will be given by using FIGS.  9  to  12  as to the first swing table operating portion  19  provided on the operating portion  3  configured to swing the first instrument swing table  10  by remote operation.  
      As shown in  FIG. 9 , the first swing table operating portion  19  is provided with the first instrument swing table operating mechanism  20  inside it and provided with the first swing table operating knob  21  which is also a part of the first instrument swing table operating mechanism  20  outside it.  
      The first instrument swing table operating mechanism  20  of the first swing table operating portion  19  includes a swing table operating portion body  22  as a structure and a rotation axis  23  fixed on the swing table operating portion body  22 . On the outside of the rotation axis  23 , an operating knob rotation cylinder  24  fixed on the first swing table operating knob  21  is fitted. The operating knob rotation cylinder  24  is rotatably fitted to the rotation axis  23 . The operating knob rotation cylinder  24  has a rotating plate  25  fitted to the distal end thereof. The rotating plate  25  is also rotatable against the rotation axis  23 . To be more specific, if the first swing table operating knob  21  is rotatively operated, the rotation of the first swing table operating knob  21  is transmitted to the rotating plate  25  via the operating knob rotation cylinder  24 .  
      To the rotating plate  25 , one ends of two L-shaped rods  26   a ,  26   b  are rotatably fitted by wheel pins  27   a ,  27   b  (refer to  FIGS. 11 and 12 ). The other ends of the rods  26   a ,  26   b  are inserted into guide holes  28   a ,  28   b  (refer to  FIGS. 11 and 12 ) formed on the swing table operating portion body  22  to be rotatably fitted to brackets  29   a ,  29   b  (refer to  FIG. 10 ). The guide holes  28   a ,  28   b  provided on the swing table operating portion body  22  are linear slits formed in a longitudinal direction of the swing table operating portion body  22 , where the rods  26   a ,  26   b  are mounted via friction reduction members  30   a ,  30   b  (refer to  FIGS. 11 and 12 ) to be able to move inside the guide holes  28   a ,  28   b  back and forth.  
      To be more specific, it is configured that, if the rotation of the first swing table operating knob  21  is transmitted to the rotating plate  25 , the rods  26   a ,  26   b  are moved in the guide holes  28   a ,  28   b  of the swing table operating portion body  22  by rotational motion of the rotating plate  25  so as to move the brackets  29   a ,  29   b  in a straight line.  
      The brackets  29   a ,  29   b  have wire joining members  31   a ,  31   b  detachably fixed thereon by screws as shown in  FIG. 10 . The wire joining members  31   a ,  31   b  have the ends of the two operating wires  32   a ,  32   b  from the first instrument swing table  10  of the distal end  5  connected and fixed thereto by solder or silver solder. The operating wires  32   a ,  32   b  are covered by operating wire guide tubes  33   a ,  33   b  respectively. The tips of the operating wire guide tubes  33   a ,  33   b  are connected to the distal end  5  in which the first instrument swing table  10  is housed in the form of opening respectively (refer to  FIG. 7 ).  
      The base sides of the wire guide tubes  33   a ,  33   b  are detachably fitted and fixed to the tips of cylinders  35   a ,  35   b  by keeping them watertight via guide tube holding members  34   a ,  34   b  provided on the first swing table operating portion  19 . The cylinders  35   a ,  35   b  are provided on the swing table operating portion body  22  to move the wire joining members  31   a ,  31   b  in a straight line.  
      The swing table operating portion body  22  is provided to an operating portion structure  55  of the operating portion  3  as shown in  FIG. 10 . On the top surface of the swing table operating portion body  22 , there are the two cylinders  35   a ,  35   b  fixed in parallel, into which the two operating wires  32   a ,  32   b  configured to remotely operate the first instrument swing table  10  are inserted respectively. A joining section of the wire joining members  31   a ,  31   b  and the brackets  29   a ,  29   b  is placed in a space different form the space connecting the inserting portion  2  with the operating portion  3 . The cylinders  35   a ,  35   b  are fitted with cleaning water supply tubes  36   a ,  36   b  for cleaning the inside of the operating wire guide tubes  33   a ,  33   b  including the operating wires  32   a ,  32   b . The other ends of the cleaning water supply tubes  36   a ,  36   b  are connected to cleaning bases  38   a ,  38   b  provided on an exterior member  37  of the swing table operating portion  19 . The cleaning bases  38   a ,  38   b  can be connected with a syringe (not shown) so as to send cleaning fluid and the like into the operating wire guide tubes  33   a ,  33   b.    
      Next, a description will be given by using  FIGS. 11 and 12  as to the relation between the rotating plate  25  of which rotation center is the rotation axis  23  and the two rods  26   a ,  26   b.    
      The rotating plate  25  centers on the rotation axis  23 , and has one ends of the rods  26   a ,  26   b  rotatably mounted at symmetrical positions by the wheel pins  27   a ,  27   b . If the first swing table operating knob  21  is turned, the rotating plate  25  turns in conjunction and the rods  26   a ,  26   b  are moved in a straight line by the. guide holes  28   a ,  28   b , which pulls one of the operating wires  32   a ,  32   b  connected to the brackets  29   a ,  29   b  provided on the other ends of the rods  26   a ,  26   b  and pushes out the other by almost the same amount. The swing table operating portion body  22  is provided with stoppers  39   a ,  39   b  for adjusting a rotation range of the rotating plate  25 . It is possible, by adjusting the stoppers  39   a ,  39   b , to regulate the rotation range of the rotating plate  25  and thereby adjust the rotation range of the first instrument swing table  10 .  
      As for the rotational position of the rotating plate  25  shown in  FIG. 11 , the first instrument swing table  10  is in a rotational state shown in  FIG. 7 , where the distal end of the first instrument  54  led out of the first instrument swing table  10  is positioned at the center of the field of view.  
      In the state of the rotational position of the rotating plate  25  in  FIG. 11 , the rods  26   a ,  26   b  are set at the position for maximizing distances L 1 , L 2  (L 1 =L 2 ) shown in the drawing to the rotation center of the wheel pins  27   a ,  27   b  connecting the rotating plate  25  with the rods  26   a ,  26   b  in the direction approximately orthogonal to the axes in the respective directions for moving in a straight line in the rotation range of the rotating plate  25  (indicated by the two-dot chain line in the drawing).  
      To be more specific, if the first swing table operating knob  21  is turned at the same speed, the speed of the linear motion of the rods  26   a ,  26   b  moving in the guide holes  28   a ,  28   b  becomes fastest when the rotating plate  25  reaches the position shown in  FIG. 11 . If the rotating plate  25  is further turned from the position of the rotating plate  25  shown in  FIG. 11 , the speed of the linear motion of the rods  26   a ,  26   b  moving in the guide holes  28   a ,  28   b  gradually decreases so that the rotating plate  25  turns to the position shown in  FIG. 12 . To be more specific, the rotation speed of the first instrument swing table  10  is slowed down by operating from the state shown in  FIG. 11  to the state shown in  FIG. 12 .  
      The rotational position of the rotating plate  25  shown in  FIG. 12  is the state where the distal end of the first instrument  54  projected from the first instrument swing table  10  shown in  FIG. 7  is A, that is, the state where it is located in the peripheral part (fully on the right side on the endoscope image) of the field of view shown in  FIG. 8 .  
      It is also possible to turn the rotating plate  25  at a constant speed with an electric motor instead of manually turning the first swing table operating knob  21 .  
      A description will be given by using FIGS.  13  to  16  as to a mucous membrane incision process of the affected region with the instrument based on endoscope observation in the body cavity by using the endoscope of such a configuration.  
      First, as shown in  FIGS. 13 and 14 , a high-frequency knife  57  as the first instrument  54  is inserted into the first instrument insertion channel  15  (not shown in  FIG. 13 ), and a grip forceps  39  as the second instrument  56  is inserted into the second instrument insertion channel  16  (not shown in  FIG. 13 ). And the first and second instrument swing tables  10 ,  11  are swung by the first swing table operating knob  21  and the second swing table operating knob  45  so as to incise the affected region.  
      To begin with, the instrument including an injection needle is inserted into the first instrument insertion channel  15  of the inserting portion  2  of the endoscope  1  inserted to the proximity of the affected region in the body cavity to inject a drug solution such as normal saline into diseased submucosa so as to upheave the entire mucosal layer including the diseased mucous membrane.  
      Next, as indicated by the dotted line in  FIG. 14 , the diseased mucous membrane or its periphery is gripped by using the grip forceps  39  which is the second instrument  56  projected from the second instrument insertion channel  16 . The grip forceps  39  is raised by the second instrument swing table  11  as shown in solid line in the drawing to lift the mucous membrane including the affected area.  
      Next, the high-frequency knife  57  as the first instrument  54  is inserted into the first instrument insertion channel  15  as a replacement, and the first instrument swing table  10  is horizontally swung. And the high-frequency knife  57  is put in contact with a foot or the submucosa of the diseased mucous membrane lifted by the grip forceps  39  to energize and incise it while horizontally swinging it.  
      A description will be given by using  FIG. 15  as to the swinging operation of the high-frequency knife  57  and the grip forceps  39  on the endoscope image of the observation means  6 .  
      The endoscope image of the affected region by the observation optical system of the observation means  6  shown in  FIG. 15  shows the state where the mucous membrane of the affected region is raised upward by the grip forceps  39  vertically swinging on the screen with the second instrument swing table  11  and the state where the high-frequency knife  57  as the first instrument  54  is located on the downside of the mucous membrane of the affected region raised by the grip forceps  39  to incise the submucosa of the affected region by horizontally swinging it with the first instrument swing table  10 .  
      When incising the affected region raised by swinging the grip forceps  39  with the second instrument swing table  11  based on the endoscope image, the first swing table operating knob  21  is turned at a constant speed, and the rotating operation (rotational motion) of the first swing table operating knob  21  is converted to linear motion for pulling the operating wires  32   a ,  32   b  by the first swing table operating portion  19 . And the high-frequency knife  57  is horizontally swung by using the first instrument swing table  10  through the linear motion of the operating wires  32   a ,  32   b . In this case, it is possible to render the swinging speed of the high-frequency knife  57  faster in proximity to a screen center Q of the endoscope image and render it slower in both the peripheral parts of the endoscope image than at the screen center Q.  
      The endoscope image shown in  FIG. 15  is an image obtained from a placement relation between the first instrument swing table  10  and the second instrument swing table  11  as against the observation means  6  shown in  FIG. 2 . As for the placement relation among the observation means  6 , the first instrument swing table  10  and the second instrument swing table  11 , the first instrument swing table  10  and the second instrument swing table  10  may be placed by turning them clockwise by 90 degrees against the center of the observation means  6  for instance. In this case, the endoscope image of  FIG. 15  has the high-frequency knife  57  as the first instrument  54  shown on the right side of the screen of the endoscope image to swing vertically on the screen. The swinging speed of the high-frequency knife  57  in this case is fastest in proximity to a center line  6  equally dividing the screen of the endoscope image vertically. Meanwhile, the grip forceps  39  is shown on the downside of the screen of the endoscope image and horizontally swings on the screen.  
      As described above, the affected region is generally picked up at the center of the screen of the endoscope image to perform cure and treatment. The peripheral part of the screen of the endoscope image is hard to see because it is not a front view, and the image looks distorted due to influence of an aberration of the observation optical system and the like. Thus, in the case of incising the mucous membrane of the affected region shown in the peripheral part of the screen of the endoscope image with the incision instrument such as the high-frequency knife, it is necessary to pay attention to the swinging speed of the instrument in particular.  
      As for the endoscope of the first embodiment of the present invention in comparison, it has a control mechanism of the first instrument swing table operating mechanism  20  so that, when it is rotatively operated at a constant speed by the swing table operating portion including the first swing table operating knob  21  configured to remotely operate on the user&#39;s side the first instrument swing table  10  configured to operate with swing table the first instrument  54  such as the high-frequency knife  57  which is an incision instrument, the swinging speed of the first instrument  54  swung by the first instrument swing table  10  is faster at the center of the screen of the endoscope image and slower in both the peripheral parts of the screen than at the center of the screen. Thus, it is possible to efficiently perform incision work of the affected region displayed at the center of the screen of the endoscope image and carefully perform safe incision work of the affected region displayed in the peripheral parts of the screen.  
      In the case of swinging with a distance to the affected region suitable for observability and curative processability of the first instrument  54  led out of the distal end face of the distal end  5  of the inserting portion  2 , such as 15 to 25 mm, the fastest moving point of the instrument  54  is set up when the distal end of the first instrument  54  reaches the center line equally dividing the field of view of the endoscope image into the right and left (six o&#39;clock direction of a clock according to the first embodiment). For this reason, the operator can easily recognize the fastest point and consequently perform the incision work more safely and efficiently.  
      The stoppers  39   a ,  39   b  configured to regulate the swinging range of the first instrument swing table  10  of the first swing table operating portion  19  is structured to regulate the rotation of the rotating plate  25  which is spatially formable with high strength rather than being provided on the thin rods  26   a ,  26   b . Therefore, the stoppers  39   a ,  39   b  are deformed little by the impact of being frequently hit by the rotating plate  25 . Consequently, the swinging range of the instrument is hardly reduced over time.  
      As for cleaning of the affected area on energization and incision of the submucosa of the diseased mucous membrane with the high-frequency knife  57  as the first instrument  54 , it is performed with cleaning water delivered to the front from the fluid delivery passage  9   a . The cleaning water after the cleaning is aspirated outward with an unshown suction pump by using the first instrument insertion channel  15 .  
      As mentioned above, in general, a tissue of the mucous membrane sticks to a blade edge of the high-frequency knife  57  when incising the diseased mucous membrane with the high-frequency knife  57 . If the incision process is continued in the state of having the tissue stuck thereon, the sticking mucous membrane carbonizes to blunt the high-frequency knife  57 .  
      Thus, as shown in the endoscope image observed from the observation means  6 , the distal ends of the first instrument  54  and the second instrument  56  swing in the range of the arrows in the drawing as they are swung by the first instrument swing table  10  and the second instrument swing table  11  described above, and the delivery from the fluid delivery passage  9   a  sends the solution to the high-frequency knife  57  as the water supply direction line S 1 . As for the operation, a description will be given by using  FIG. 16  as to the operation of incising the diseased mucous membrane in the body cavity based on the observation by the endoscope image which shows the swinging of the first instrument  54  and the second instrument  56  and the water supply direction line S 1 .  
      If the tissue of the incised mucous membrane sticks to the high-frequency knife  57 , the high-frequency knife  57  is moved to the direction of the water supply direction line S 1  of the fluid delivery passage  9   a  by the first instrument swing table  10  so as to deliver the fluid such as the cleaning water or the air from the fluid delivery passage  9   a . It is possible, by means of the fluid from the fluid delivery passage  9   a , to remove the tissue of the mucous membrane sticking to the high-frequency knife  57  which has been moved to the position of the water supply direction line S 1  of the fluid delivery passage  9   a .  
      To be more specific, if the delivery direction of the front water supply port  9  is the center line (center of the screen) Q equally dividing the field of view of the observation means  6  into the right and left, it is possible, by setting the water supply direction line S 1  penetrating inside the swinging area of the first instrument swing table  10 , to easily move the high-frequency knife  57  as the first instrument  54  on the endoscope image toward the water supply direction line S 1  so as to allow the high-frequency knife  57  to be cleaned by the fluid delivered in front.  
      It is thereby possible to perform an incision action while alternately repeating the mucous membrane incision and cleaning in the state of having the high-frequency knife  57  inserted into the first instrument insertion channel  15 . Therefore, the efficiency of incision operation improves.  
      Conventionally, in the case of cleaning a wide range of the affected area with the cleaning water delivered to the front from the fluid delivery passage  9   a , the water was supplied in front while bending the bending portion  14  of the inserting portion  2 . As for the endoscope of the present invention, however, if the first instrument  54  is swung by the first instrument swing table  10  while sending the cleaning water to the front from the fluid delivery passage  9   a , the cleaning water sent from the fluid delivery passage  9   a  is sent by way of the surface of the first instrument  54 . Therefore, the cleaning water sent through the narrow water supply direction line S 1  from the fluid delivery passage  9   a  is diffused by the first instrument  54  to allow the cleaning of the wide range. Consequently, the cleaning of the wide range is possible by a simple operation of just manipulating the instrument swing table without performing a conventional bending operation.  
      The first instrument swing table  10  of the endoscope of the present invention has the first channel opening  53  connected to the distal end of the first instrument insertion channel  15  as described by using  FIG. 8 . The first channel opening is in an elliptic shape which is longer in the horizontal direction than in the vertical direction when viewed from the front as indicated by the dashed line G in the drawing of  FIG. 2 . For this reason, the first instrument  54  can swing at a wide angle without being sandwiched between the first instrument swing table  10  and the distal end component  51  so as to improve the efficiency of the incision work by the first instrument  54 . An opening width W 1  in the swinging direction of the first channel opening  53  is larger than an inside diameter W 2  of the first instrument insertion channel  15 . It is thereby possible to take a large deflection in the first channel opening  53  of the first instrument  54  swung by the first instrument swing table  10  so that the swinging range of the first instrument  54  can be expanded. As for the vertical opening width of the first channel opening  53 , there is no influence on the swinging of the first instrument  54  even if it is rendered narrower than the swinging direction. Therefore, it is possible to render an outside diameter of the distal end  5  thinner.  
      Furthermore, the opening of the first storage room  28  in which the first instrument swing table  10  is housed is provided with a notched portion  30  with a part of the electric insulating cover  52  in an irregular shape. Therefore, it is possible to swing the first instrument  54  at a wide angle without putting the first instrument  54  and the first instrument swing table  10  in contact with the electric insulating cover  52 . To be more specific, it is possible to provide the endoscope capable of a wide range of incision without increasing the outside diameter of the distal end  5  as much as possible.  
      Furthermore, the opening position of the fluid delivery passage  9   a  is provided at a location of a distance E from the distal end face of the distal end  5 . Therefore, it is possible to secure the minimum distance E between an open end of the fluid delivery passage  9   a  and the mucous membrane by performing the delivery to the front in the state where the distal end  5  is in close contact with or adjacent to the mucous membrane so that a water supply pressure on the mucous membrane can be reduced.  
      And now, it is necessary to clean the endoscope once the observation in the body cavity and curative treatment using the instruments are finished. In the cleaning of the endoscope, it takes a lot of trouble to clean every part of the complicated shape and structure by using a cleaning brush when cleaning the distal end component  51  of the inserting portion  2  of the endoscope  1  having the complicated shape and structure and provided with the instrument swing table. If multiple instrument swing tables are provided, the shape and structure become further complicated and there are some portions where the cleaning brush cannot reach. Thus, the cleaning required a lot of labor and meticulous care.  
      Consequently, the endoscope provided here is the one capable of easily and securely performing the cleaning of the endoscope having the instrument swing table provided at the distal end of the inserting portion. As described above by using  FIG. 4 , the distal end component  51  of the distal end  5  of the inserting portion  2  of the endoscope  1  has the first storage room  28  and the second storage room  29  configured to house the first instrument swing table  10  and the second instrument swing table  11  formed in conjunction in a C portion in the drawing.  
      As shown in  FIG. 17 , a cleaning cap  59  is mountable on the periphery and the distal end face of the electric insulating cover  52  covering the periphery of the distal end component  51  of such shape and structure. The cleaning cap  59  is formed by an elastic material such as rubber, and is detachably mountable on the distal end face and the periphery of the distal end face side of the distal end  5 .  
      When cleaning the distal end  5 , if the cleaning water is sent from the fluid delivery passage  9   a  after mounting the cleaning cap  59 , the cleaning water bounces off the cleaning cap  59  as indicated by the arrow in the drawing, circulates to the first storage room  28  of the first instrument swing table  10  and also circulates from the joining section of C through the first storage room  28  to the second storage room  29  having the second instrument swing table  11  housed therein.  
      To be more specific, if the cleaning water is sent from the fluid delivery passage  9   a  after mounting the cleaning cap  59  on the distal end face side of the distal end  5 , the cleaning water is circulated by the cleaning cap  59  to the first and second storage rooms  28 ,  29  having the first and second instrument swing tables  10 ,  11  housed therein so as to allow the first and second instrument swing tables  10 ,  11  to be securely cleaned.  
      The cleaning water having cleaned the first and second instrument swing tables  10 ,  11  is drained by using the first and second instrument insertion channels  15 ,  16 .  
      In  FIG. 17 , the cleaning cap  59  covers the entire end face of the distal end  5 . However, the cleaning cap  59  has to have at least a position for bouncing the cleaning water sent to the front from the fluid delivery passage  9   a , that is, a wall configured to bounce the cleaning water on the water supply direction line S 1 . The portions other than that may be in a shape having a partial opening. If in such a shape, the cleaning water having cleaned the insides of the first and second storage rooms  28 ,  29  can flow outside from the partial opening. Therefore, it is possible to make it harder for the cleaning water after the cleaning to go into another duct of the distal end  5 .  
      Next, a description will be given by using  FIGS. 18 and 19  as to the endoscope of a second embodiment of the present invention.  FIG. 18  is a sectional view showing the configuration of the first instrument swing table operating portion of the endoscope, and  FIG. 19  is an explanatory diagram for describing the action on the endoscope image screen of the instrument operated by the first instrument swing table operating portion of the endoscope. The same portions as those in FIGS.  1  to  17  are given the same symbols, and a detailed description thereof will be omitted.  
      The endoscope of the second embodiment is basically the same as the above-mentioned first embodiment, where it is possible to set the swinging range of the first instrument swing table  10  in the first swing table operating portion  19  to be different.  
      To be more precise, as shown in  FIG. 18 , the rotation range of the rotating plate  25  of the first swing table operating portion  19  is regulated by the stoppers  39   a ,  39   b  to differentiate the horizontal swing range of the first instrument swing table  10 .  
      As shown in the drawing, an adjustment is made by the stopper  39   b  to stop the guide hole  28   b  at the position for maximizing the distance L 2  from a central axis on which the rod  26   b  moves in a straight line to the center of the wheel pin  27   b  rotatively fixing the rod  26   b  on the rotating plate  25 .  
      Thus, an adjustment is made by the stopper  39   b  to stop the leftward rotation of the rotating plate  25  in the drawing at the position for maximizing the distance L 2  between the center of the liner motion of the rod  26   b  and the center of the wheel pin  27   b . And if the rotating plate  25  is rotated rightward in the drawing, the distance L 2  becomes rotatable in the rotation range as indicated by the two-dot chain line in the drawing as in the above-mentioned first embodiment.  
      Thus, if an adjustment is made by the stoppers  39   a ,  39   b  as to the rotation range of the rotating plate  25 , the horizontal swinging on the screen of the high-frequency knife  57  as the first instrument  54  is one-sided swinging only rightward in the drawing from the center line (center of the screen) Q equally dividing the field of view of the endoscope image into the right and left on the screen of the endoscope image observed by the observation optical system of the observation means  6  as shown in  FIG. 11 . In the one-sided swinging, it is possible to render the swinging speed faster in proximity to the center line Q of the screen of the endoscope image and render it slower in the peripheral parts of the screen of the endoscope image than at the center of the screen.  
      Consequently, the swinging of the first instrument  54  is only one-sided. However, it has the same action and effects as those of the aforementioned first embodiment.  
      Next, the endoscope of a third embodiment according to the present invention will be described by using FIGS.  20  to  22 .  FIG. 20  is a plan view showing the configuration of the distal end face of the distal end of the endoscope inserting portion,  FIG. 21  is a sectional view cut at a section line XXI to XXI of  FIG. 20  and showing the configuration of the distal end of the endoscope inserting portion, and  FIG. 22  is an explanatory diagram for describing the screen of the endoscope image observed by the endoscope. The same portions as those in FIGS.  1  to  19  are given the same symbols, and a detailed description thereof will be omitted.  
      As shown in  FIG. 20 , only the first instrument swing table  10  is provided as the instrument swing table on the distal end face of the distal end  5  of the endoscope inserting portion according to the third embodiment. As only the first instrument swing table  10  is provided at the distal end  5 , the rotation axis R of the first instrument swing table  10  does not horizontally match with the center line Q equally dividing the field of view of the observation means  6  into the right and left when viewed from the distal end front of the distal end  5 . As shown in  FIG. 21 , a central axis P 1  of the first instrument  54  inserted into the first instrument insertion channel  15  and straightly led out to the front of the distal end  5  by way of the instrument inserting portion  40  of the first instrument swing table  10  does not horizontally match with the rotation axis R of the first instrument swing table  10  when viewed from the distal end front of the distal end  5 .  
      Thus, in the case where the center line Q in the field of view direction of the observation means  6  and the central axis P 1  of the first instrument  54  straightly led out do not horizontally match with the rotation axis R of the first instrument swing table  10  when viewed from the distal end front of the distal end  5 , the position of the first instrument swing table  10  according to the first swing table operating portion  19  is set up so that the distal end of the first instrument  54  led out of the first instrument swing table  10  is on the center line Q of the field of view of the observation means  6  as indicated in solid line in  FIG. 21 . To be more specific, a setup is made so that, when the distal end of the first instrument  54  shown in  FIG. 21  is positioned on the center line Q of the field of view of the observation means  6 , the distance L 1  (=L 2 ) becomes maximum in the rotation range indicated by the rotating plate  25  of the first swing table operating portion  19  in  FIG. 11 .  
      An angle α 1  in the drawing of  FIG. 21  is a central area in the horizontal direction against the entire horizontal field of view S of the observation means  6 , and is equivalent to approximately ¼ (α=F/4) of the entire field of view F.  
      According to such a configuration, if the first swing table operating knob  21  is turned at a constant speed, it is possible, with the first swing table operating portion  19 , to let the distal end of the first instrument  54  increase the swinging speed in a central area al of the field of view of the observation means  6  and reduce the swinging speed in the peripheral parts beyond the central area al according to the swinging of the first instrument swing table  10 .  
      To be more specific, as to the screen of the endoscope image observed from the observation means  6 , the high-frequency knife  57  as the first instrument  54  can increase the swinging speed in the shaded central area al in the horizontal direction of the field of view on the screen of the endoscope image and reduce the swinging speed in the peripheral parts of the screen on the right and left outside the central area α 1  to be slower than the central area α 1 . Consequently, it is possible to have the same action and effects as those of the aforementioned first embodiment.  
      Next, a description will be given by using FIGS.  23  to  26  as to the endoscope of a fourth embodiment of the present invention.  FIG. 23  is a plan view showing the configuration of the distal end of the endoscope,  FIG. 24  is a sectional view showing the configuration of the distal end of the endoscope, which is cut at a section line XXIV to XXIV shown in  FIG. 23 .  FIG. 25  is a sectional view showing the configuration of the distal end of the endoscope, which is cut at a section line XXV to XXV shown in  FIG. 23 , and  FIG. 26  is a sectional view for describing a detergent action of the distal end of the endoscope. The same portions as those in FIGS.  1  to  22  are given the same symbols, and a detailed description thereof will be omitted.  
      A distal end  5 ′ of the endoscope according to the fourth embodiment has an opening shape and a front water supply direction of the fluid delivery passage  9   a  different from those provided to the distal end  5  of the above-mentioned first embodiment. As shown in  FIG. 23 , as for the opening position of the fluid delivery passage  9   a  provided to the distal end  5 ′ of the second embodiment, the opening width  11  of the fluid delivery passage  9   a  in an approximately perpendicular direction to the swinging direction of the first instrument swing table  10  is placed within a width of a vertical swinging area of the instrument when the instrument projected from the first instrument swing table  10  is horizontally swung, that is, within a vertical width  12  of the first instrument inserting portion  40  of the first instrument swing table  10  as in the above-mentioned first embodiment.  
      The opening shape of the distal end face of the distal end  5 ′ of the fluid delivery passage  9   a ′ is formed in the elliptic shape in the vertical direction in the drawing when the distal end face of the distal end  5 ′ is viewed from the front. To be more specific, the cross-sectional shape of the fluid delivery passage  9   a ′ is formed in the shape vertically expanding toward the distal end face side of the distal end  51  in the drawing as shown in  FIG. 24 . To be more specific, the water supply from the fluid delivery passage  9   a ′ has a water supply form in the elliptic shape of which opening shape is vertically long.  
      As shown in  FIG. 25 , the water supply direction line S 1  of the fluid delivery passage  9   a ′ is not set up to send water to the center line Q equally dividing the field of view of the observation means  6  into the right and left. Instead, it is set up to be approximately parallel therewith. To be more specific, as described by using  FIG. 3 , it has only to be set up to be the water supply direction line S 1  for passing through the swinging area of the first instrument swing table  10 . As the ellipse-shaped water is sent in the swinging area, it becomes possible to remove the mucous tissue sticking to the first instrument  54  swung by the first instrument swing table  10  and clean the affected area in the incision process.  
      It is also possible to mount the cleaning cap  59  shown in  FIG. 26  on the distal end  51 . The cleaning cap  59  is mounted on the distal end face side of the distal end  5 ′ on which the fluid delivery passage  9   a ′ is open. Inside the cleaning cap  59 , a concave portion  36  is formed in the portion opposed to the water supply direction line S 1  of the fluid delivery passage  9   a ′ of the distal end  5 ′. The concave portion  36  is partially overlapping the first storage room  28  of the first instrument swing table  10 .  
      If the cleaning water is sent from the fluid delivery passage  9   a ′ to the front with the cleaning cap  59  mounted, the cleaning water bounces off the concave portion  36  of the cleaning cap  59 , circulates in the first storage room  28  to clean the first instrument swing table  10  and also circulates to the second storage room  29  to clean the second instrument swing table  11 .  
      Next, a description will be given by using FIGS.  27  to  29  as to the endoscope of a fifth embodiment of the present invention.  FIG. 27  is a plan view showing the configuration of the distal end of the endoscope,  FIG. 28  is an explanatory diagram for describing the swinging operation of the instrument in the endoscope image of the endoscope, and  FIG. 29  is an explanatory diagram for describing the operation of the endoscope. The same portions as those in FIGS.  1  to  26  are given the same symbols, and a detailed description thereof will be omitted.  
      As for the endoscope of the fifth embodiment, a first instrument swing table  10 ′ and a second instrument swing table  11 , are different from the above-mentioned first instrument swing table  10  and second instrument swing table  11 . The endoscope of the third embodiment has the configuration in which the first and second instrument swing tables of the above-mentioned first embodiment are replaced.  
      As shown in  FIG. 27 , a distal end  5 ″ of the endoscope of the fifth embodiment is provided with the first instrument swing table  10 ′ horizontally swung by one operating wire  32   c , and a second instrument swing table  11 ′ vertically swung by two operating wires  32   a ′,  32   b ′. The first instrument swing table  10 ′ is swung by inserting a first instrument  54 ′ which is a grip forceps while the second instrument swing table  11 ′ is swung by inserting a second instrument  56 ′ which is an incision instrument such as a high-frequency knife. It is the same as the first embodiment except for the first and second instrument swing tables  10 ′ and  11 ′. In particular, the opening position of the fluid delivery passage  9   a  and the water supply direction line S 1  are also the same as those described by using  FIG. 3 .  
      The first instrument inserting portion  40 ′ of the first instrument swing table  10 ′ is in a cylindrical shape covering the entire circumference of the first instrument  54 ′ which is a grip forceps to be inserted not shown. However, it may also be in a partially notched shape. Reference character V in the drawing denotes the first channel opening  53 . If the first instrument  54  is inserted into the first instrument inserting portion  40  in the state where the first instrument swing table  10  is inverted, the first instrument  54  projects by inclining to the fluid delivery passage  9   a  side when viewed from the front.  
      As for swinging motion of the first instrument  54 ′ which is a grip forceps and the second instrument  56 ′ which is a high-frequency knife projected from the first instrument swing table  10  and the second instrument swing table  11 ′ respectively in the endoscope image picked up by the observation means  6  of the endoscope with the configuration of the distal end  5 ″, they swing in the range of the arrows in the drawing and the water supply direction line S 1  for sending the water from the fluid delivery passage  9   a  to the front is recognized as shown in  FIG. 28 .  
      The water supply direction line S 1  sends the water to both the first instrument  54 ′ and the second instrument  56 ′. To be more specific, the water supply direction line S 1  is configured in the direction which penetrates the area in which the swinging area of the first instrument  54 ′ intersects with the swinging area of the second instrument  56 ′.  
      The amount of projection from the distal end face of the distal end  5 ″ of the first instrument  54 ′ and the second instrument  56 ′ is a distance suitable for observability and processability of the affected area, such as 15 to 25 mm.  
      Thus, it is possible to obtain the same action and effects as those of the aforementioned first embodiment even when the first instrument swing table and the second instrument swing table have different configurations.  
      The one operating wire  32   c ′ of the first instrument swing table  10 ′ of the distal end  5 ″, is operated by a swing table operating portion  19 ′ including a first swing table operating knob  21 ′ of an operating portion  3 ′ shown in  FIG. 18  while the two operating wires  32   a ′,  32   b ′ of the second instrument swing table  11 ′ is operated by the second swing table operating knob  45  of the operating portion  31 .  
      As for the operation of the endoscope in general, the first swing table operating knob  21  is provided at a position operable by a right hand on gripping a gripper of the operating portion  3  by a left hand while a second swing table operating knob  21  is provided at a position operable by the left hand as described by using  FIG. 13 .  
      When performing the incision process of the mucous membrane by operating the first swing table operating knob  21  and the second swing table operating knob  21  and swinging the first instrument  54  and the second instrument  56  via the first instrument swing table  10  and the second instrument swing table  11 , the high-frequency knife as an incision instrument is used as the first instrument  54  of the first instrument swing table  10  operated by the first swing table operating knob  21  while the grip forceps as a grip instrument is used as the second instrument  56  of the second instrument swing table  11  operated by the second swing table operating knob  21 . For this reason, as for the incision process of the mucous membrane, there is an overwhelmingly high frequency of operating the first swing table operating knob  21  for swinging the high-frequency knife.  
      Meanwhile, in addition to the operation of the first swing table operating knob  21 , the right hand needs to simultaneously perform the operation of inserting, advancing, retreating and twisting the inserting portion  2  in the body cavity and the operation of inserting, advancing and retreating the first instrument  54  and the second instrument  56  in the first instrument insertion channel  15  and the second instrument insertion channel  16  from the first opening  17  and the second opening  18 .  
      In comparison, the left hand performs the operation of the second swing table operating knob  21 , the operation of the air and water supply control button  46 , the operation of the suctioning control button  47 , the operation of the image recording button  48  and the operation of the bending operating knob  49  and the like of which frequencies of operation are relatively low. Thus, careful operations as well as highly frequent operations are required of the right hand.  
      Thus, the one operating wire  32   c , configured to operate the first instrument swing table  10 ′ of the distal end  5 ″ described by using  FIG. 27  is connected to the swing table operating portion  19 , having the first swing table operating knob  21 ′ provided thereon as shown in  FIG. 29 . And the two operating wires  32   a ′,  32   b , configured to operate the second instrument swing table  11 ′ are connected to the swing table operating portion having the second swing table operating knob  21 ′ provided thereon.  
      Thus, the right hand of high frequencies of various operations performs the operation of lifting the mucous membrane with the grip forceps of the first instrument  54 ′ by the first instrument swing table  10 ′ while the left hand performs a swing table operation of the high-frequency knife of the second instrument  56 ′ by the second instrument swing table  11 . Thus, the right hand can be dedicated to the operation of inserting, advancing, retreating and twisting the inserting portion  2  of the endoscope  1  in the body cavity and the operation of inserting, advancing and retreating the instrument, and the left hand performs the swing table operation of the high-frequency knife so that the incision work can be smoothly performed by the endoscope.  
      The present invention is not limited to the embodiments, but various other deformations may be implemented without departing from the scope thereof in an implementation phase. Furthermore, the embodiments include the inventions of various stages so that various inventions can be extracted by adequately combining multiple configuration requirements which are disclosed.  
      For instance, even if some of the configuration requirements are deleted out of all the configuration requirements indicated in the embodiments, the configuration having the configuration requirements deleted therefrom can be extracted as an invention in the case where the problems described in the means for solving the problem can be solved and the effects described in advantages of the invention can be obtained.