Patent Publication Number: US-2012029290-A1

Title: Endoscope apparatus and optical adapter used in the endoscope apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention The present invention relates to an endoscope apparatus and an optical adapter. 
     2. Description of the Related Art 
     In recent years, endoscopes have been widely used in the medical and industrial fields. 
     An endoscope used in the medical field can observe an organ inside a body cavity that is a site to be examined by inserting an elongated insertion portion into the body cavity. As necessary, the endoscope can perform various kinds of treatment using a treatment instrument that is inserted inside a treatment instrument insertion channel. 
     Further, an endoscope used in the industrial field, by inserting the elongated insertion portion inside a jet engine or pipes of a factory or the like as a site to be examined, can be used for observation to check for the presence of flaws or corrosion or the like at the site to be examined and to perform various kinds of repairs. 
     An objective optical system, an image pickup section that has an image pickup device such as a CCD, and an illumination section that illuminates a site to be examined and the like are provided in a distal end portion of an insertion portion of an endoscope. A configuration is also known in which the objective optical system and the illumination section are provided in a detachable optical adapter at the distal end portion of the insertion portion. 
     Various types of optical adapters are available. Examples thereof include a single lens front-view type, a single lens side-view type, a binocular front-view type, and a binocular side-view type. The various types of optical adapters are appropriately used according to an observation target and an intended use. 
     Generally, to improve an observation performance of an endoscope, cleaning is performed that wipes off dirt that is adhered to an observation window and the like provided on a distal end face of a distal end portion of an insertion portion of the endoscope by ejecting fluid towards the observation window and the like through a spout that is similarly provided in the distal end face. 
     In an endoscope used in the industrial field also, it is necessary to clean an observation window and the like using fluid to improve an observation performance, and in particular, there is a strong need with respect to endoscope apparatuses to which the aforementioned plurality of kinds of optical adapters can be detachably attached. 
     A conventional technology relating to optical adapters in which a conduit for supplying fluid is provided inside the aforementioned types of optical adapters includes, for example, an endoscope apparatus described in Japanese Patent Application Laid-Open Publication No. 2007-195798. 
     The endoscope apparatus described in Japanese Patent Application Laid-Open Publication No. 2007-195798 has a water storage section that stores water inside a lens barrel part that is included in a distal end adapter, and includes a linear adapter-side conduit that is provided in substantially the insertion axis direction. The endoscope apparatus is configured so as to dissipate heat of the lens barrel part that is transmitted from LED chips inside the distal end portion of the insertion portion by adopting a configuration such that water is supplied to the adapter-side conduit from a water supply tube which communicates with the adapter-side conduit, and inside the endoscope insertion portion and stored in the water storage section, and an excessive amount of water flows to a drainage channel. 
     SUMMARY OF THE INVENTION 
     An endoscope apparatus according to one aspect of the present invention includes a plurality of kinds of optical adapters having an illuminating window that radiates an illuminating light and an observation window through which a subject can be viewed, and an endoscope insertion portion having a distal end portion to which the plurality of optical adapters can be detachably attached, wherein: a fluid spout that ejects fluid at least at the observation window, and fluid inlet whose arrangement position is common among the plurality of kinds of optical adapters and that is connected to and communicates with a fluid supply port for supplying the fluid that is arranged on a distal end face of the distal end portion of the endoscope insertion portion are provided in each of the optical adapters; and a fluid supply channel that causes the fluid inlet and the fluid spout to communicate and in which the fluid flows and the fluid spout are configured differently according to a kind of the optical adapter. 
     Further, according to another aspect of the present invention, there is provided a plurality of kinds of optical adapters that can be detachably attached to a distal end portion of an endoscope insertion portion and that have an illuminating window that radiates an illuminating light and an observation window through which a subject can be viewed, wherein: a fluid spout that ejects fluid at least at the observation window, and a fluid inlet that is connected to and communicates with a fluid supply port for supplying the fluid that is arranged on a distal end face of the distal end portion of the endoscope insertion portion are provided in each of the optical adapters; and a fluid supply channel that causes the fluid inlet and the fluid spout to communicate and in which the fluid flows and the fluid spout are configured differently according to a kind of the optical adapter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view that shows a configuration of an endoscope apparatus according to Embodiment 1 of the present invention; 
         FIG. 2  is a perspective view that shows a configuration of a distal end portion of an endoscope insertion portion shown in  FIG. 1 ; 
         FIG. 3  is a front view that shows a configuration of a distal end face of the distal end portion shown in  FIG. 2 ; 
         FIG. 4  is a perspective view of a single lens front-view optical adapter shown in  FIG. 1 , as viewed from a side that is attached to the insertion portion; 
         FIG. 5  is a side view of the single lens front-view optical adapter shown in  FIG. 4 ; 
         FIG. 6  is a front view that shows a configuration of a distal end face of the single lens front-view optical adapter shown in  FIG. 5 ; 
         FIG. 7  is a plan view of the single lens front-view optical adapter shown in  FIG. 5 , as viewed from a side that is attached to an insertion portion; 
         FIG. 8  is a view that shows a distal end face side of the endoscope apparatus to which an optical adapter shown in  FIG. 1  is attached; 
         FIG. 9  is a sectional view along a line A-A in  FIG. 8 ; 
         FIG. 10  is a sectional view that shows a modification example of the single lens front-view optical adapter according to Embodiment 1, which shows a configuration of an endoscope apparatus to which the optical adapter is attached; 
         FIG. 11  is a perspective view that shows a configuration of the endoscope apparatus shown in  FIG. 10 ; 
         FIG. 12  is a perspective view that shows a configuration of an endoscope apparatus according to Embodiment 2 of the present invention; 
         FIG. 13  is a perspective view of a single lens side-view optical adapter shown in  FIG. 12 , as viewed from a side that is attached to an insertion portion; 
         FIG. 14  is a side view of the single lens side-view optical adapter shown in  FIG. 13 ; 
         FIG. 15  is a front view that shows a configuration of a distal end face of the single lens side-view optical adapter shown in  FIG. 13 ; 
         FIG. 16  is a plan view of the single lens side-view optical adapter shown in  FIG. 13 , as viewed from a side that is attached to an insertion portion; 
         FIG. 17  is a view that shows a distal end face side of an endoscope apparatus to which the optical adapter shown in  FIG. 13  is attached; 
         FIG. 18  is a sectional view along a line B-B in  FIG. 17 ; 
         FIG. 19  is a perspective view that shows a configuration of an endoscope apparatus according to Embodiment 3 of the present invention; 
         FIG. 20  is a perspective view of a binocular front-view optical adapter shown in  FIG. 19 , as viewed from a side that is attached to an insertion portion; 
         FIG. 21  is a side view of the binocular front-view optical adapter shown in  FIG. 20 ; 
         FIG. 22  is a front view that shows a configuration of a distal end face of the binocular front-view optical adapter shown in  FIG. 20 ; 
         FIG. 23  is a plan view of the binocular front-view optical adapter shown in  FIG. 20 , as viewed from a side that is attached to an insertion portion; 
         FIG. 24  is a view that shows a distal end face side of an endoscope apparatus to which the binocular front-view optical adapter shown in  FIG. 20  is attached; 
         FIG. 25  is a sectional view along a line C-C in  FIG. 24 ; 
         FIG. 26  is a sectional view along a line D-D in  FIG. 24 ; 
         FIG. 27  is a perspective view that shows a configuration of an endoscope apparatus according to Embodiment 4 of the present invention; 
         FIG. 28  is a perspective view of the endoscope apparatus shown in  FIG. 27 , as viewed from a diagonally downward direction in the figure; 
         FIG. 29  is a perspective view of a binocular side-view optical adapter shown in  FIG. 28 , as viewed from a side that is attached to an insertion portion; 
         FIG. 30  is a side view of the binocular side-view optical adapter shown in  FIG. 28 ; 
         FIG. 31  is a front view that shows a configuration of a distal end face of the binocular side-view optical adapter shown in  FIG. 28 ; 
         FIG. 32  is a plan view of the binocular side-view optical adapter shown in  FIG. 28 , as viewed from a side that is attached to an insertion portion; 
         FIG. 33  is a view that shows a distal end face side of the endoscope apparatus to which an optical adapter shown in  FIG. 27  is attached; 
         FIG. 34  is a sectional view along a line E-E in  FIG. 33 ; 
         FIG. 35  is a sectional view along a line F-F in  FIG. 33 ; 
         FIG. 36  is a sectional view along a line G-G in  FIG. 34 ; and 
         FIG. 37  is a sectional view along a line H-H in  FIG. 35 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention are described in detail hereunder while referring to the accompanying drawings. 
     Embodiment 1 
       FIG. 1  to  FIG. 9  illustrate Embodiment 1 of an endoscope apparatus according to the present invention. 
     As shown in  FIG. 1 , an endoscope apparatus  1  of the present embodiment includes a flexible, elongated endoscope insertion portion (hereunder, abbreviated to insertion portion)  2  that is inserted into a body cavity or a structure, and a plurality of kinds of optical adapters  4  that can be detachably attached to a distal end portion  3  provided on a distal end side of the insertion portion  2 . 
     First, a configuration of the distal end portion  3  of the insertion portion  2  will be described using  FIG. 2 ,  FIG. 3  and  FIG. 9 . 
     As shown in  FIG. 2 , a protruding portion  3 A that protrudes in an insertion direction is provided on a distal end side of the distal end portion  3  of the insertion portion  2 . An observation window  11 , an illuminating window  12 , and a fluid supply port  13  that constitute a distal end portion-side connection portion  10  are provided on a distal end side of the protruding portion  3 A. 
     As shown in  FIG. 2  and  FIG. 3 , the observation window  11 , the illuminating window  12 , and the fluid supply port  13  are arranged at previously determined positions. 
     More specifically, as shown in  FIG. 2 , the observation window  11  and the fluid supply port  13  are arranged in first concave portions  3 X provided in the distal end face  3 B of the protruding portion  3 A. The illuminating window  12  is arranged in a second concave portion  3 Y provided in a flat portion  3 C that is formed in a predetermined shape at a more rear position than the distal end face  3 B by notching a portion of the distal end side of the protruding portion  3 A. 
     By adopting this configuration, even if another member contacts the distal end portion  3  of the insertion portion  2  before attaching the optical adapter  4  to the distal end portion  3 , another member does not contact the observation window  11 , the illuminating window  12 , and the fluid supply port  13  that constitute the distal end portion-side connection portion  10 . More specifically, the distal end portion-side connection portion  10  can be protected. 
     Further, as shown in  FIG. 3 , on a plane including the distal end face  3 B and the flat portion  3 C of the protruding portion  3 A, the observation window  11  and the illuminating window  12 , for example, are disposed on a straight line that passes through an axis L of the distal end portion  3 . Further, the fluid supply port  13  is arranged at a previously determined position so as to be adjacent to the observation window  11  and the illuminating window  12 . 
     A positioning groove  15  for performing positioning when fixing the optical adapter  4  is provided on a side face portion of the protruding portion  3 A of the distal end portion  3 . Further, an O-ring  16  is provided on an outer circumferential face of the protruding portion  3 A, at a position on a rear end side of the positioning groove  15 . The O-ring  16  maintains a space between the distal end portion  3  and the optical adapter  4  in a watertight state when the optical adapter  4  is attached to the distal end portion  3 . 
     An image pickup unit  24  is provided on a rear side (direction towards the interior of the distal end portion) of the observation window  11 . The image pickup unit  24  includes an objective optical lens group  25 , a solid image pickup device  26 , and a control substrate  27  that are located to the rear of the observation window  11 . A signal wire that transmits a drive control signal of the solid image pickup device  26  through the control substrate  27 , and a signal wire  28  that transmits a video signal of a site to be examined that is generated by the solid image pickup device  26  are connected to the solid image pickup device  26 . The signal wire  28  is provided inside a signal cable  29  that is led out from the proximal end side of the image pickup unit  24 . The signal cable  29  is inserted through the inside of the insertion portion  2  and guided to the inside of an unshown apparatus main body. 
     The illuminating window  12  projects an illuminating light onto an observation site via the optical adapter  4 . A distal end face of a light guide fiber, which is not shown in the drawings, is disposed at a proximal end face of the illuminating window  12 . The light guide fiber is inserted through the inside of the insertion portion  2  and connected to a light source apparatus of the apparatus main body via a connector (unshown). 
     Further, as shown in  FIG. 9 , the fluid supply port  13  is a distal end-side opening of a supply passage  30   a  of an insertion portion-side fluid connection member (hereunder, referred to as “fluid supply section”)  13   b.  An air/water supply conduit  30  for supplying fluid is arranged in a proximal end-side opening of the supply passage  30   a  of the fluid supply section  13   b.  The fluid supply section  13   b  is a pipe member that has a flange portion at a center in the longitudinal direction, and an O-ring  13   a  is disposed at an outer circumference thereof that is further on the distal end side than the flange portion. 
     The air/water supply conduit  30  passes through the inside of the insertion portion  2  and is connected to an unshown air/water supply apparatus inside the apparatus main body. Fluid such as water or air that is supplied from the air/water supply apparatus is delivered to the fluid supply port  13 . 
     When the optical adapter  4  is attached to the distal end portion  3 , a space between the fluid supply port  13  and a fluid inlet  20 , described later, of the optical adapter  4  that is connected to the fluid supply port  13  is maintained in a watertight state by the O-ring  13   a.    
     In this connection, similarly to the fluid supply port  13 , an O-ring may be provided to the observation window  11  and the illuminating window  12 , respectively. In addition to ensuring adherence at the time of connection to the optical adapter-side connection portion  17  (see  FIG. 4 ), the O-ring is configured to absorb a contact force at the time of connection, and prevent breakage or the like occurring due to the contact force. 
     Next, a configuration of the optical adapter  4  is described using  FIG. 1  and  FIG. 4  to  FIG. 9 . 
     Various kinds of optical adapters  4  such as a single lens front-view type, a single lens side-view type, a binocular front-view type, and a binocular side-view type are available as the optical adapter  4 . The optical adapter  4  according to the present embodiment is configured as a single lens front-view adapter for observing a site to be examined that is on the front side in the insertion direction. 
     As shown in  FIG. 1  and  FIG. 4 , the optical adapter  4  has a main body  5  and a retaining ring  6  that has a fitting hole  6 A in which the distal end portion  3  of the insertion portion  2  fits. The optical adapter  4  is configured so as to be integrally fixed to the distal end portion  3  by screwing a female screw portion provided on an inner circumferential face of the retaining ring  6  with a male screw portion provided on an outer circumferential face of the distal end portion  3  in a state in which the distal end portion  3  is fitted in the fitting hole  6 A. 
     As shown in  FIG. 7 , a positioning protruding portion  15 A is provided on the inner circumferential face of the optical adapter  4 . The positioning protruding portion  15 A performs positioning when fixing the optical adapter  4  to the distal end portion  3  of the insertion portion  2  by fitting in the positioning groove  15  provided in the distal end portion  3  (see  FIG. 2 ). 
     As shown in  FIG. 9 , the main body  5  includes an adapter main body  21  in which the retaining ring  6  is pivotably provided at a proximal end portion, and a distal end cover  22  that is a cover member of the adapter main body  21 . 
     As shown in  FIG. 1  and  FIG. 6 , the distal end cover  22  has an opening  5 X that exposes one portion of a distal end face  5 A of the adapter main body  21 . The distal end cover  22  is fixed to the adapter main body  21  by screwing with a fastening screw  4   a  that is arranged on a side portion. 
     As shown by a broken line in  FIG. 6 , a concave portion  200   b  that is included in a fluid supply channel  31  is provided at a previously determined position on a back surface side of the distal end cover  22 . The concave portion  200   b  includes a fluid spout  9  for ejecting fluid towards the observation window  7 . Further, as shown by a broken line in  FIG. 6 , an opening  32   a  of an adapter-side fluid supply conduit  32 , which is described later, which is included in the fluid supply channel  31  is provided on the distal end face  5 A of the adapter main body  21 . The opening  32   a  communicates with the concave portion  200   b  (see  FIG. 9 ). 
     Furthermore, an observation window  7  and an illuminating window  8  that are exposed from the opening  5 X are provided in the distal end face  5 A of the adapter main body  21 . 
     In this connection, although the fluid spout  9  is formed so as to be capable of ejecting fluid towards the observation window  7 , the fluid spout  9  may also be configured to be capable of ejecting fluid not only towards the observation window  7 , but also towards the illuminating window  8  at the same time. 
     According to the present embodiment, as shown in  FIG. 1 ,  FIG. 4  and  FIG. 9 , the optical adapter  4  includes the fluid spout  9  that ejects fluid towards at least the observation window  7 , the fluid inlet  20  that connects to and communicates with the fluid supply port  13  for supplying the fluid that is arranged on the distal end face of the distal end portion of the endoscope insertion portion, and the fluid supply channel  31  that allows the fluid inlet  20  and the fluid spout  9  to communicate and through which the fluid flows. The arrangement position of the fluid inlet  20  is common among the plurality of kinds of optical adapters  4 , while the fluid spout  9  and the fluid supply channel  31  are configured differently according to the kind of the respective optical adapters  4 . 
     The configuration of the main portions of the optical adapter  4  will now be described using  FIG. 4  to  FIG. 9 . 
     As shown in  FIG. 4  and  FIG. 7 , an observation window portion  18 , an illuminating window portion  19  and the fluid inlet  20  that constitute the optical adapter-side connection portion  17  are provided on a side that is attached to the distal end portion  3  of the insertion portion  2 , which is the proximal end side of the optical adapter  4 . 
     The observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  are respectively arranged at positions that conform to the arrangement positions of the observation window  11 , the illuminating window  12  and the fluid supply port  13  that constitute the distal end portion-side connection portion  10  of the insertion portion  2 . 
     The observation window portion  18  and the fluid inlet  20  are arranged on a bottom face  5 B of the adapter main body  21  that makes surface contacts with the protruding portion  3 A of the distal end portion  3 . The illuminating window portion  19  is arranged on a protruding portion  5 C that protrudes further in the attaching side direction than the bottom face  5 B. 
     Specifically, as shown in  FIG. 7 , similarly to the connection portion  10  of the distal end portion  3 , the observation window portion  18  and the illuminating window portion  19  are, for example, disposed on a straight line that passes through an axis L 1  of the optical adapter  4 , on a plane including the face of the protruding portion  5 C and the bottom face  5 B of the adapter main body  21 . Further, the fluid inlet  20  is arranged at a previously determined position adjacent to the observation window portion  18  and the illuminating window portion  19 . 
     As shown in  FIG. 9 , objective lenses  18   a  and  23  for observing an observation site are arranged in order from the attaching side in the insertion direction in the observation window portion  18 . The observation window  7  (see  FIG. 1 ) is provided on the front side in the insertion direction of the objective lens  23 . 
     Further, although not shown in the drawings, a light guide or a lens that transmits an illuminating light is arranged in the illuminating window portion  19 . The illuminating window  8  (see  FIG. 1 ) is provided on a front side in the insertion direction of the light guide or the lens. 
     As shown in  FIG. 9 , the fluid inlet  20  is a proximal end-side opening of an inlet passage  200   a  of an adapter-side fluid connection member (hereunder, referred to as fluid inflow portion)  20   a.  A distal end-side opening of the inlet passage  200   a  of the fluid inflow portion  20   a  communicates with the adapter-side fluid supply conduit  32  that is included in the fluid supply channel  31 . 
     The fluid inflow portion  20   a  is a stepped tubular member, and has a protruding portion  20   b  that has a thick diameter that protrudes towards the attaching side direction of the distal end portion  3 . A concave portion is provided in the protruding portion  20   b.  The part of the fluid supply section  13   b  that is on the distal end side than the flange portion is arranged in the concave portion. When the optical adapter  4  is attached to the distal end portion  3 , an end face of the protruding portion  20   b  contacts against the O-ring  13   a  that is arranged at the fluid supply section  13   b,  and presses against the O-ring  13   a  to achieve water-tightness. Thus, fluid that is supplied via the air/water supply conduit  30  is supplied to the adapter-side fluid supply conduit  32  from the fluid supply port  13  via the fluid inlet  20  without leaking to outside. 
     The adapter-side fluid supply conduit  32  is formed in the adapter main body  21  so as to communicate in a straight line the distal end-side opening of the fluid supply section  20   a  and the fluid spout  9 . That is, according to the present embodiment, the fluid supply channel  31  is constituted by the inlet passage  200   a  that is formed in the fluid inflow portion  20   a,  the adapter-side fluid supply conduit  32  that is formed in the adapter main body  21 , the concave portion  200   b,  and the fluid spout  9 . 
     Fluid that is supplied from the fluid supply port  13  to the inlet passage  200   a  via the fluid inlet  20  passes through the adapter-side fluid supply conduit  32  and the concave portion  200   b  and is ejected towards the observation window  7  via the fluid spout  9 . 
     In this connection, similarly to the distal end portion-side connection portion  10 , the observation window portion  18 , the illuminating window portion  19  and the fluid inlet  20  that constitute the optical adapter-side connection portion  17  are provided at positions that are more recessed than a proximal end face  6 B (see  FIG. 5 ) that is formed on an proximal end side of the retaining ring  6  included in the optical adapter  4 . 
     According to this configuration, even if another member contacts the retaining ring  6  of the optical adapter  4  before attaching the optical adapter  4  to the distal end portion  3 , the existence of the outer circumferential edge portion that forms the proximal end face  6 B of the retaining ring  6  prevents the other member from contacting the observation window portion  18 , the illuminating window portion  19  and the fluid inlet  20  that constitute the optical adapter-side connection portion  17 . More specifically, the optical adapter-side connection portion  17  can be protected. 
     Operations of the endoscope apparatus  1  in a state in which the optical adapter  4  having the above configuration is attached to the distal end portion  3  of the insertion portion  2  will now be described using  FIG. 1  and  FIG. 9 . 
     In the endoscope apparatus  1  shown in  FIG. 9 , when fluid such as water or air is supplied to the air/water supply conduit  30  from an unshown air/water supply apparatus, the fluid passes through the fluid supply port  13  and the fluid inlet  20  and is fed to the fluid supply channel  31  formed in the optical adapter  4 . 
     The fluid that is fed to the fluid supply channel  31  is supplied to the inlet passage  200   a  and the adapter-side fluid supply conduit  32 , and is ejected towards the observation window  7  from the fluid spout  9  via the concave portion  200   b  that is formed on a back face of the distal end cover  22  from the opening  32   a  of the adapter-side fluid supply conduit  32 . As a result, dirt adhering to the observation window  7  is removed by the fluid ejected from the fluid spout  9 . 
     Thus, according to the single lens front-view optical adapter  4  of Embodiment 1, since fluid can be appropriately ejected towards the observation window  7  and the like, it is possible to prevent observation from being obstructed by adherents or the like that adhere to the observation window  7 , and the observation performance can be improved. 
     Note that the shape of the fluid spout  9  of the optical adapter  4  is not limited to the shape shown in  FIG. 1  and  FIG. 6 , and the fluid ejecting strength or the ejecting direction can be set as desired by suitably changing the shape thereof. 
     For example, the fluid spout  9  can be configured as shown in  FIG. 10  and  FIG. 11 . In the optical adapter  4  shown in  FIG. 10 , the fluid spout  9  is formed integrally with the adapter main body  21 . As a result, the same actions and advantages as described above can be obtained. 
     According to an optical adapter  4 A of an endoscope apparatus  1 A shown in  FIG. 11 , a fluid spout member  9 A is provided in a fixed condition by means of an adhesive or a welding at a predetermined position on the distal end face  5 A of an adapter main body  22 . The fluid spout member  9 A has a fluid passage and a fluid spout  9   a  that communicate with the opening  32   a  of the adapter-side fluid supply conduit  32 . According to this configuration, although the number of components increases, the same actions and advantages as in the above described Embodiment 1 can be easily obtained. 
     In this connection, according to the present embodiment, the arrangement of the observation window  11 , the illuminating window  12 , and the fluid supply port  13  in the distal end portion  3  of the insertion portion  2  is not limited to the positions shown in  FIG. 3 . For example, the arrangement positions of the observation window  11 , the illuminating window  12 , and the fluid supply port  13  may be suitably changed based on a configuration that is suited to reducing the diameter of the insertion portion  2 . Likewise, the arrangement positions of the observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  in the optical adapter  4  are also not limited to the positions shown in  FIG. 7 . In this connection, when changing the positions, a configuration is adopted such that the arrangement positions of the observation window  11 , the illuminating window  12 , and the fluid supply port  13  that constitute the distal end portion-side connection portion  10  of the insertion portion  2  and the arrangement positions of the observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  in the optical adapter  4  are in conformity with each other. 
     Embodiment 2 
       FIG. 12  to  FIG. 18  illustrate Embodiment 2 of the endoscope apparatus according to the present invention. In this connection, in the following description of an endoscope apparatus  1 B illustrated in  FIG. 12  to  FIG. 18 , components that are the same as in the foregoing Embodiment 1 are denoted by the same reference symbols and a description of those components is omitted, and only portions that are different to that of Embodiment 1 are described. 
     The endoscope apparatus  1 B of the present embodiment has the same insertion portion  2  as those of Embodiment 1. Instead of the single lens front-view type optical adapter  4 , an optical adapter  4 B that is a single lens side-view adapter that performs observation of a site to be examined in a direction orthogonal to the insertion direction is provided on the insertion portion  2 . 
     As shown in  FIG. 12  to  FIG. 18 , a side-view face  33  and an inclined face  34  are provided in the main body  5  of the optical adapter  4 B. The side-view face  33  and the inclined face  34  are formed by notching a part of a side face portion of the main body  5 . The side-view face  33  is oriented in a direction orthogonal to the insertion direction. The inclined face  34  is formed in a diagonal direction with respect to the side-view face  33 . 
     The observation window  7  is provided at substantially the center of the side-view face  33 . Illuminating windows  8  are respectively provided on the two sides of the observation window  7  of the side-view face  33 . 
     A fluid spout member  9 B that has the fluid spout  9   a  is provided on the side-view face  33  side of the inclined face  34 . A flow channel  201   b  that communicates with the fluid spout  9   a  is formed in the fluid spout member  9 B. Another end of the flow channel  201   b  communicates with an adapter-side fluid supply conduit  32 A, described later, which constitutes a fluid supply channel  31 A. 
     Therefore, the configuration is such that when fluid is supplied through the fluid supply channel  31 A, the fluid is ejected towards the observation window  7  from the fluid spout  9   a  of the fluid spout member  9 B. In this connection, similarly to Embodiment 1, an ejecting direction of the fluid spout  9   a  is not limited to the direction of the observation window  7 , and a configuration may be adopted in which fluid is also ejected towards the illuminating windows  8  to thereby enable the ejection of fluid towards the windows  7  and  8 . 
     According to the present embodiment, as shown in  FIG. 13  to  FIG. 16 , the observation window portion  18 , the illuminating window portion  19  and the fluid inlet  20  that constitute the optical adapter-side connection portion  17  are provided on the proximal end side of the optical adapter  4 B in substantially the same condition as in Embodiment 1. 
     The fluid supply channel  31 A of the optical adapter  4 B is used for a single lens side-view type optical adapter, and is formed so that fluid can be appropriately ejected towards the observation window  7  and the like. 
     The fluid supply channel  31 A of the optical adapter  4 B includes the flow channel  201   b  of the fluid spout member  9 B, a groove channel  35 A, an inlet passage  201   a  of a fluid inflow portion  20   a,  and the adapter-side fluid supply conduit  32 A. The fluid inflow portion  20   a  is constituted by the inlet passage  201   a  and the adapter-side fluid supply conduit  32 A. 
     More specifically, as shown in  FIG. 13 ,  FIG. 14 ,  FIG. 16  and  FIG. 18 , a groove channel portion  35  that is one part of the fluid supply channel  31  is provided on a bottom face  5 B that is an end face that has the fluid inlet  20  of the optical adapter  4 B. That is, the groove channel portion  35  constituting the groove channel  35 A that is one portion of the fluid supply channel  31  is formed on the bottom face  5 B of the optical adapter  4 B. 
     As shown in  FIG. 18 , the groove channel portion  35  is formed in a groove shaped by recessing one portion of the bottom face  5 B of the adapter main body  21 , and communicates with the inlet passage  201   a  of the fluid inflow portion  20   a  and the adapter-side fluid supply conduit  32 A. As shown in  FIG. 16 , on a flat surface of the bottom face  5 B, the groove channel portion  35  is formed in a curved shape so as to cause the fluid inlet  20  and the flow channel  201   b  to communicate. 
     Further, the groove channel portion  35  constitutes the groove channel  35 A that is one portion of the fluid supply channel  31  by adhering thereto a cover  35 C that is aligned with a groove of the groove channel portion  35 . 
     A curved shape of the groove channel portion  35  is not limited to the shape shown in  FIG. 13  and  FIG. 16 , and a configuration may be adopted that is appropriately changed in accordance with arrangement positions of the observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  that are suited to reducing the diameter of the optical adapter  4  or the like. 
     Further, to prevent leakage of fluid from the fluid supply channel  31  by means of the groove channel portion  35 , a configuration may be adopted in which, instead of the cover  35 C, for example, an O-ring is provided at an outer circumferential edge portion of the groove channel portion  35  to make a space between the distal end face  3 B of the distal end portion  3  and the bottom face  5 B of the optical adapter  4 B watertight, to thereby seal the groove channel  35 A with greater precision by means of the groove channel portion  35 . 
     The remaining configuration is the same as Embodiment 1. 
     Next, operations of the endoscope apparatus  1 B according to Embodiment 2 will be described. In the endoscope apparatus  1 B shown in  FIG. 18 , fluid such as water or air is supplied to an air/water supply conduit  30  from an unshown air/water supply apparatus. The fluid passes through a fluid supply port  13  and the fluid inlet  20  and is fed to the fluid supply channel  31 A. 
     The fluid that is fed to the fluid supply channel  31 A is supplied to the adapter-side supply conduit  32   a,  the inlet passage  201   a,  the groove channel  35 A formed by the groove channel portion  35 , and the flow channel  201   b  formed in the fluid spout member  9 B, and is sent to the fluid spout  9   a  of the fluid spout member  9 B and ejected towards the observation window  7 . As a result, dirt adhering to the observation window  7  is removed by the ejected fluid. 
     Thus, according to Embodiment 2, even when the optical adapter  4  is a single lens side-view type optical adapter, by providing the fluid supply channel  31 A in the optical adapter it is possible to appropriately eject fluid towards the observation window  7  and the like, and hence the observation performance can be improved. 
     Note that according to the present embodiment also, the shape of the fluid spout  9   a  of the optical adapter  4 B is not limited to the shape shown in  FIG. 12  and  FIG. 15 , and a configuration may be adopted in which the fluid ejecting strength or the ejecting direction is set as desired by suitably changing the shape thereof. 
     Embodiment 3 
     Embodiment 3 of the endoscope apparatus according to the present invention is illustrated in  FIG. 19  to  FIG. 26 . In this connection, in the following description of an endoscope apparatus  1 C illustrated in  FIG. 19  to  FIG. 26 , components that are the same as in the foregoing embodiments are denoted by the same reference symbols and a description of those components is omitted, and only portions that are different to those of the foregoing embodiments are described. 
     The endoscope apparatus  1 C of the present embodiment has the same insertion portion  2  as those of Embodiments 1 and 2. Instead of the above described optical adapter  4 , an optical adapter  4 C that is a binocular front-view adapter for performing binocular observation of a site to be examined that is at a forward position in the insertion direction is provided on the insertion portion  2 . 
     As shown in  FIG. 19  and  FIG. 22 , although the configuration of the main body  5  of the optical adapter  4 C is substantially the same as in Embodiment 1 above, instead of the observation window  7 , a binocular observation window  7 A is provided on the distal end face  5 A of the adapter main body  21 . 
     Further, with respect to the fluid spout  9  formed by the distal end cover  22  also, although the configuration is substantially the same as that of the above Embodiment 1, the shape of the fluid spout  9  is formed in conformity with the binocular observation window  7 A whose area is greater than that of the observation window  7 . 
     More specifically, even in the case of the binocular observation window  7 A that has a large area, the fluid spout  9  is configured so that fluid can be reliably ejected towards the binocular observation window  7 A. 
     According to the present embodiment, since the optical adapter  4 C is a binocular front-view adapter, an objective lens and a binocular optical unit  40  that is required for performing binocular observation of a site to be examined that is forward of the optical adapter  4 C in the insertion direction are arranged in the binocular observation window  7 A. 
     As shown in  FIG. 25 , the binocular optical unit  40  is arranged to a rear of the binocular observation window  7 A, and includes a pair of left and right objective optical lenses  41  that are required in order to capture video of a site to be examined as video light for binocular viewing, and a first objective lens group  42  and a second objective lens group  43  that are arranged to a rear of the objective optical lenses  41 . The observation window portion  18  is arranged to a rear of the second objective lens group  43  via an objective lens  18   a.    
     According to the present embodiment, similarly to Embodiment 1, the observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  that constitute the optical adapter-side connection portion  17  are provided on the proximal end side of the optical adapter  4 C. 
     In this case, as described above, since the binocular optical unit  40  for a binocular front-view is provided inside the main body of the binocular front-view optical adapter  4 C, the length of the main body  5  in the insertion axis direction (longitudinal direction) is increased, and a space to arrange the adapter-side fluid supply conduit  32  for supplying fluid is limited. 
     Although the optical adapter  4 C of the present embodiment is a binocular front-view optical adapter, the optical adapter  4 C includes a fluid supply channel  31 B that can appropriately eject fluid towards the binocular observation window  7 A and the like. 
     The fluid supply channel  31 B of the optical adapter  4 C is formed to include a conduit in which a channel that links the fluid inlet  20  and the fluid spout  9  is curved so as to correspond to a structure of the binocular front-view optical adapter  4 C. 
     More specifically, as shown in  FIG. 25  and  FIG. 26 , the fluid supply channel  31 B includes the inlet passage  200   a  of the fluid inflow portion  20   a,  a first supply conduit  44  that is linearly provided along the insertion direction that communicates with the fluid inlet  20 , a second supply conduit  45  that is linearly provided along an opposite direction to the insertion direction from the distal end face  5 A via the fluid spout  9 , the concave portion  200   b,  and the fluid spout  9 . 
     As shown in  FIG. 26 , a central axis of the first supply conduit  44  and a central axis of the second supply conduit  45  are out of alignment with each other in a direction orthogonal to the insertion direction. The first supply conduit  44  and the second supply conduit  45  are caused to communicate by being formed so that a portion of the first supply conduit  44  and a portion of the second supply conduit  45  overlap. 
     The first supply conduit  44  included in the fluid supply channel  31 B is formed by performing a boring operation from the bottom face  5 B side that is the proximal end face of the adapter main body  21 . In contrast, the second supply conduit  45  is formed by performing a boring operation from the distal end face  5 A side of the adapter main body  21  so that one portion of the second supply conduit  45  overlaps with the first supply conduit  44 . Accordingly, there is the advantage that the fluid supply channel  31 B can be formed more simply than the curved fluid supply channel  31 A of Embodiment 2. 
     The remaining configuration is the same as that of Embodiment 1. 
     Next, the operations of the endoscope apparatus  1 C of Embodiment 3 are described. 
     In the endoscope apparatus  1 C shown in  FIG. 26 , when fluid such as water or air is supplied to the air/water supply conduit  30  from an unshown air/water supply apparatus, the fluid passes through the fluid supply port  13  and the fluid inlet  20  and is fed to the fluid supply channel  31 B formed in the optical adapter  4 . 
     The fluid that is fed to the fluid supply channel  31 B passes through the inlet passage  200   a,  the first supply conduit  44 , the second supply conduit  45 , and the opening  32   a  of the adapter fluid supply conduit  32 , and is ejected towards the binocular observation window  7 A from the fluid spout  9  via the concave portion  200   b  formed in the back face of the distal end cover  22 . As a result, dirt adhering to the binocular observation window  7 A is removed by the fluid ejected from the fluid spout  9 . 
     Thus, according to Embodiment 3, even when the optical adapter  4  is a binocular front-view optical adapter, by providing the fluid supply channel  31 B in the optical adapter, it is possible to appropriately eject fluid towards the binocular observation window  7 A and the like, and hence the observation performance can be improved. 
     Note that according to the present embodiment also, the shape of the fluid spout  9  of the optical adapter  4 C is not limited to the shape shown in  FIG. 19  and  FIG. 22 , and a configuration may be adopted in which the fluid ejecting strength or the ejecting direction is set as desired by suitably changing the shape thereof. 
     Further, in addition to the shape of the fluid spout, with respect to the first supply conduit  44  and the second supply conduit  45  of the adapter-side fluid supply conduit  32  also, a configuration may be adopted in which the diameter of the supply conduits is suitably changed so as to obtain a required fluid supply pressure or the like. 
     Embodiment 4 
       FIG. 27  to  FIG. 37  illustrate Embodiment 4 of the endoscope apparatus according to the present invention. In this connection, in the following description of an endoscope apparatus  1 D illustrated in  FIG. 27  to  FIG. 37 , components that are the same as in the foregoing embodiments are denoted by the same reference symbols and a description of those components is omitted, and only portions that are different to those of the foregoing embodiments are described. 
     The endoscope apparatus  1 D of the present embodiment has the same insertion portion  2  as those of Embodiments 1 and 2. Instead of the above described single lens side-view optical adapter  4 B, the insertion portion  2  is provided with an optical adapter  4 D that is a binocular side-view adapter for performing binocular observation of a site to be examined in a direction orthogonal to the insertion direction. 
     As shown in  FIG. 27  to  FIG. 28 , although the configuration of the main body  5  of the optical adapter  4 D is substantially the same as that of the foregoing Embodiment 2, in addition to the side-view face  33  and the inclined face  34 , a second inclined face  34 A that links to the inclined face  34  is newly provided in the optical adapter  4 D. The second inclined face  34 A is formed in a direction that inclines further from the inclined face  34 . 
     Further, the binocular observation window  7 A is provided instead of the observation window  7  (see  FIG. 12 ) on the side-view face  33 . In addition, the two illuminating windows  8  (see  FIG. 12 ) provided on the side-view face  33  are eliminated, and one illuminating window  8  is newly provided on the second inclined face  34 A. 
     More specifically, by adopting a configuration in which the illuminating window  8  is arranged at a position that is further to a rear in the opposite direction to the insertion direction than the binocular observation window  7 A of the optical adapter  4 D, a site to be examined of a wider range can be illuminated and binocular observation can be performed with precision. 
     With respect to fluid spouts  9   a  of a fluid spout member  9 C provided on the side-view face  33  side of the inclined face  34  also, although the configuration thereof is substantially the same as the fluid spout  9   a  of the foregoing Embodiment 2, the fluid spouts  9   a  are formed so as to conform to the binocular observation window  7 A whose area is greater than that of the observation window  7 . 
     More specifically, the fluid spout member  9 C is provided with two fluid spouts  9   a  so that, even in the case of the binocular observation window  7 A that has a large area, fluid can be reliably ejected towards the binocular observation window  7 A. 
     According to the present embodiment, since the optical adapter  4 D is a binocular side-view optical adapter, an objective lens (not shown) and a binocular optical unit  40 A that is required for performing binocular observation of a site to be examined in a direction orthogonal to the insertion direction are arranged in the binocular observation window  7 A. 
     As shown in  FIG. 36 , the binocular optical unit  40 A is arranged to the rear of the binocular observation window  7 A, and includes a pair of left and right objective optical lenses  41  that are required in order to capture video of a site to be examined as video light for binocular viewing, and a first objective lens group  42  and a second objective lens group  43  that are arranged to the rear of the objective optical lenses  41 . The observation window portion  18  is arranged to the rear of the second objective lens group  43  via the objective lens  18   a.    
     According to the present embodiment, similarly to Embodiment 2, the observation window portion  18 , the illuminating window portion  19 , and the fluid inlet  20  that constitute the optical adapter-side connection portion  17  are provided on the proximal end side of the optical adapter  4 D. 
     As described above, since the binocular optical unit  40 A for a binocular side-view is provided inside the main body of the binocular side-view optical adapter  4 D, the length of the main body  5  in the insertion axis direction (longitudinal direction) is increased, and a space to arrange the adapter-side fluid supply conduit  32  for supplying fluid is limited. 
     Although the optical adapter  4 D of the present embodiment is a binocular side-view optical adapter, the optical adapter  4 D includes a fluid supply channel  31 C that can appropriately eject fluid towards the binocular observation window  7 A and the like. 
     The fluid supply channel  31 C of the optical adapter  4 D is formed to include a conduit in which a channel that links the fluid inlet  20  and the fluid spout  9   a  is curved so as to correspond to the structure of the binocular side-view optical adapter  4 D. 
     More specifically, as shown in  FIG. 30  and  FIG. 34  to  FIG. 37 , the fluid supply channel  31 C includes the inlet passage  200   a  of the fluid inflow portion  20   a,  a first supply conduit  50  that is linearly provided along the insertion direction through the fluid inlet  20 , the concave portion  200   b,  the fluid spouts  9   a,  the conduit  9   c  provided in the fluid spout member  9 C, a second supply conduit  52  that is linearly provided along an opposite direction to the insertion direction and that communicates with the fluid spouts  9   a,  a third supply conduit  51  that is provided in a direction orthogonal to the insertion direction and that causes the first supply conduit  50  and the second supply conduit  52  to communicate, and a fourth supply conduit  53  that is provided in a direction orthogonal to the insertion portion and that causes the conduit  9   c  and the second supply conduit  52  to communicate. 
     The first supply conduit  50  included in the fluid supply channel  31 C is formed by performing a boring operation from the bottom face  5 B side that is the proximal end face of the adapter main body  21 . In contrast, the second supply conduit  52  is formed by performing a boring operation from the distal end face  5 A side of the adapter main body  21 . 
     Further, the third supply conduit  51  is formed by performing a boring operation so as to cause the first supply conduit  50  and the second supply conduit  52  to communicate, from a side face on the proximal end side of the adapter main body  21 . In contrast, the fourth supply conduit  53  is formed by performing a boring operation so as to cause the conduit  9   c,  which supplies fluid to the fluid spout  9   a,  and the second supply conduit  51  to communicate, from a side face on the distal end side of the adapter main body  21 . 
     In this connection, after completing the respective operations to bore the third supply conduit  51  and the fourth supply conduit  53 , hole plugging operations are performed in which the respective openings provided in the side face portions of the adapter main body  21  are sealed using a lid member such as a resin or a filling member such as an adhesive. 
     The remaining configuration is the same as that of Embodiment 2. 
     Next, the operations of the endoscope apparatus  1 D of Embodiment 4 are described. In the endoscope apparatus  1 D shown in  FIG. 37 , when fluid such as water or air is supplied to the air/water supply conduit  30  from an unshown air/water supply apparatus, the fluid passes through the fluid supply port  13  and the fluid inlet  20  and is fed to the fluid supply channel  31 C. 
     As shown in  FIG. 30  and  FIG. 34  to  FIG. 37 , the fluid that is fed to the fluid supply channel  31 C passes through the inlet passage  200   a,  the first supply conduit  50 , the second supply conduit  52 , the third supply conduit  51 , the fourth supply conduit  53 , and the conduit  9   c  of the fluid spout member  9 C, and is ejected towards the binocular observation window  7 A from the two fluid spouts  9   a.  As a result, dirt adhering to the binocular observation window  7 A is removed by the fluid ejected from the fluid spouts  9   a.    
     Thus, according to Embodiment 4, even when the optical adapter  4  is the binocular side-view optical adapter  4 D, by providing the fluid supply channel  31 C in the optical adapter, it is possible to appropriately eject fluid towards the binocular observation window  7 A and the like, and hence the observation performance can be improved. 
     Note that according to the present embodiment also, the shape of the fluid spouts  9   a  of the optical adapter  4 D is not limited to the shape shown in  FIG. 28  and  FIG. 37 , and a configuration may be adopted in which the fluid ejecting strength or the ejecting direction is set as desired by suitably changing the shape thereof. 
     Further, in addition to the shape of the fluid spouts  9   a,  with respect to the first supply conduit  50  to the fourth supply conduit  53  of the fluid supply channel  31 C also, a configuration may be adopted in which the diameter of the supply conduits is suitably changed or the length is changed so as to obtain a required fluid supply pressure or the like. 
     Furthermore, although according to the present embodiment the two fluid spouts  9   a  are configured so as to eject fluid towards only the binocular observation window  7 A, a configuration may also be adopted that enables a fluid to be ejected towards the illuminating window  8  at the same time by, for example, providing a dedicated fluid supply conduit for the illuminating window  8  that branches from the fluid supply channel  31 C as well as a dedicated fluid spout for the illuminating window  8  that communicates with the fluid supply conduit on the second inclined face  34 . 
     Note that, according to the present invention, when a configuration is adopted in which the fluid supply channel  31  bends or curves, the shape of the fluid supply channel  31  is not limited to a shape shown in Embodiments 2 to 4, and even when another shape is adopted, for example, even when the optical adapter  4  has a reduced diameter, the fluid supply channel  31  may be configured using a flexible, elastic conduit or the like that can be freely arranged so as to run along a space inside the optical adapter  4 . 
     The present invention is not limited to the above described embodiments and modification examples, and various changes and modifications are possible within a range that does not depart from the spirit and the scope of the present invention.