Patent Publication Number: US-2007106119-A1

Title: Endoscope

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an endoscope for industrial and medical purposes to be used with an image pickup adaptor that is attached to the endoscope and comprising electric devices, such as a light emitting diode, on a distal end of an elongated insertion portion to be inserted into a body lumen.  
      2. Description of Related Art  
      Generally, as an endoscope to be used for industrial and medical purposes, an endoscope has been proposed that is used with an image pickup adaptor attached to a distal end of an insertion portion of the endoscope and comprising a light emitting diode (hereinafter, referred to as LED) as an illumination light source for illuminating a subject to be observed inside a body lumen to perform observation and image pickup easily.  
      Since the image pickup adaptor and the insertion portion are separated from each other in such an endoscope, an endoscope has been proposed in which the image pickup adaptor and the insertion portion are conducted by bringing an insertion portion side electrode terminal into contact with a plate spring having an appropriate degree of biasing force in order to ensure a reliable connection between the image pickup adaptor and the insertion portion (for example, Japanese Unexamined Patent Application, First Publication No. 2005-27851 ( FIG. 6 )). In this case, the plate spring and the insertion portion side electrode terminal are formed so that a condition of their contact sufficient to ensure conduction is maintained  
      Meanwhile, in the case where electric power is to be supplied to an electric device such as a LED arranged within the image pickup adaptor, electrode terminals for connection are arranged on both the image pickup adaptor and the insertion portion. In this case, in order to reliably supply electric power to the electric device, both of the electrode terminals need to be reliably brought in contact with each other. Therefore, an endoscope having a structure for establishing contact by bringing an elastic spring in contact with a hard electrode terminal or by using male/female connectors has been proposed (Japanese Unexamined Patent Application, First Publication No. H10-328131 ( FIG. 5 )).  
      Incidentally, in the endoscope mentioned above, following expansion in its application, reduction in an outer diameter of the insertion portion from approximately 12 to 13 mm, used in a general endoscope apparatus, to approximately 0.5 mm, used for inserting into a blood vessel, has been achieved.  
      Against such a background, the image pickup adaptor and the insertion portion are required to have an attachment/removal structure that enables reliable electrical connection, and a connection structure that does not impede a reduction in the diameter of the insertion portion.  
     SUMMARY OF THE INVENTION  
      The endoscope according to the present invention is characterized in that it is an endoscope comprising: an insertion portion formed in an elongated cylindrical shape; a cylindrical shaped image pickup adaptor, the pickup adaptor comprising, an electric device arranged on the distal end side thereof; and a proximal end side of the image pickup adaptor being attached to and removed from the distal end side of the insertion portion, wherein a pair of adaptor side electrode terminals continuous with the electric device are lined up in a direction different to the direction in which the image pickup adaptor and the insertion portion are attached and detached to and from each other, and are arranged on the image pickup adaptor facing in a direction orthogonal to the above direction, and a pair of insertion portion side electrode terminals that respectively come into contact with and are electrically connected to the pair of adaptor side electrode terminals, are arranged on the insertion portion so as to respectively face, and be able to come in contact with, the pair of adaptor side electrode terminals, when the image pickup adaptor is attached to the insertion portion.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, wherein the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are arranged in pairs in a direction different from the direction in which the image pickup adaptor and the insertion portion are attached to and detached from each other.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, wherein the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are arranged so as to face each other in a direction orthogonal to the direction in which the image pickup adaptor and the insertion portion are attached to and detached from each other.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, wherein the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are arranged so as to face each other in a direction inclined at a constant angle to the direction in which the image pickup adaptor and the insertion portion are attached to detached from each other.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, further comprising an aligning section which adjusts the orientation of the image pickup adaptor to the direction in which the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals face each other, when the image pickup adaptor is attached to the insertion portion.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, further comprising a biasing device which adjusts a pressing force of the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals, when the image pickup adaptor is attached to the insertion portion.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, wherein at least one of the pair of insertion portion side electrode terminals and the pair of adaptor side electrode terminals is formed from an elastic member.  
      Preferably, an endoscope according to the present invention is the aforementioned endoscope, wherein the pair of insertion portion side electrode terminals and the pair of adaptor side electrode terminals comprise facing surfaces that face each other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1A  is a perspective view showing an endoscope according to a first embodiment of the present invention when disassembled.  
       FIG. 1B  is a perspective view showing the endoscope according to the first embodiment of the present invention when assembled and housed.  
       FIG. 2A  is an exploded perspective view showing the endoscope according to the first embodiment of the present invention.  
       FIGS. 2B and 2C  are perspective views showing an adaptor of the endoscope according to the first embodiment of the present invention.  
       FIG. 3A  is a longitudinal sectional view showing the adaptor of the endoscope according to the first embodiment of the present invention.  
       FIG. 3B  is a longitudinal sectional view showing a distal end of an insertion portion of the endoscope according to the first embodiment of the present invention  
       FIG. 4  is a longitudinal sectional view showing an adaptor and a distal end of an insertion portion of an endoscope according to a second embodiment of the present invention.  
       FIG. 5A  is an exploded perspective view showing an endoscope according to a third embodiment of the present invention.  
       FIG. 5B  is a longitudinal sectional view showing an adaptor of the endoscope according to the third embodiment of the present invention.  
       FIG. 5C  is a front view seen from a proximal end side showing the adaptor of the endoscope according to the third embodiment of the present invention.  
       FIG. 6A  is an exploded perspective view showing an endoscope according to a fourth embodiment of the present invention.  
      FIG,  6 B is a longitudinal sectional view showing an adaptor of the endoscope according to the fourth embodiment of the present invention.  
       FIG. 6C  is a longitudinal sectional view showing a distal end of an insertion portion of the endoscope according to the fourth embodiment of the present invention.  
       FIG. 7A  is an exploded perspective view showing a principal portion of an adaptor of an endoscope according to a fifth embodiment of the present invention.  
       FIG. 7B  is a longitudinal sectional view showing the adaptor and a distal end of an insertion portion of the endoscope according to the fifth embodiment of the present invention.  
       FIG. 8A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to a sixth embodiment of the present invention.  
       FIG. 8B  is a perspective view showing a principal portion of the distal end of the insertion portion of the endoscope according to the sixth embodiment of the present invention.  
       FIG. 8C  is a longitudinal sectional view showing the distal end of the insertion portion of the endoscope according to the sixth embodiment of the present invention.  
       FIG. 9A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to a seventh embodiment of the present invention.  
       FIG. 9B  is a perspective view showing a principal portion of the adaptor of the endoscope according to the seventh embodiment of the present invention,  
       FIG. 10A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to an eighth embodiment of the present invention.  
       FIG. 10B  is a perspective view showing a principal portion of the adaptor of the endoscope according to the eighth embodiment of the present invention.  
       FIG. 11A  is a perspective view showing a modification of a distal end of an insertion portion of the endoscope according to the eighth embodiment of the present invention  
       FIG. 11B  is a perspective view showing a principal portion of a modification of the adaptor of the endoscope according to the eighth embodiment of the present invention.  
       FIG. 12A  is an exploded perspective view showing an adaptor of an endoscope according to a ninth embodiment of the present invention.  
       FIG. 12B  is a longitudinal sectional view showing the adaptor of the endoscope according to the ninth embodiment of the present invention.  
       FIG. 13A  is an exploded perspective view showing a modification of the adaptor of the endoscope according to the ninth embodiment of the present invention.  
       FIG. 13B  is a longitudinal sectional view showing a modification of the adaptor of the endoscope according to the ninth embodiment of the present invention.  
       FIG. 14A  is an exploded perspective view showing an endoscope according to a tenth embodiment of the present invention.  
       FIG. 14B  is a longitudinal sectional view showing a distal end of an insertion portion according to the tenth embodiment of the present invention.  
       FIG. 14C  is a longitudinal sectional view showing an adaptor according to the tenth embodiment of the present invention.  
       FIG. 15A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to an eleventh embodiment of the present invention.  
       FIG. 15B  is a development view showing a flexible substrate on an insertion portion side of the distal end of the insertion portion of the endoscope according to the eleventh embodiment of the present invention.  
       FIG. 15C  is a perspective view showing a flexible substrate on an insertion portion side of a distal end of an insertion portion of the endoscope according to the eleventh embodiment of the present invention.  
       FIG. 15D  is a peeve view showing the distal end of the insertion portion of the endoscope according to the eleventh embodiment of the present invention.  
       FIG. 15E  is a side view showing an insert flexible substrate on the insertion portion side of the distal end of the insertion portion of the endoscope according to the eleventh embodiment of the present invention.  
       FIG. 15F  is a diagram showing an insert flexible substrate on the insertion portion side of the distal end of the insertion portion of the endoscope according to the eleventh embodiment of the present invention.  
       FIG. 16A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to a twelfth embodiment of the present invention.  
       FIG. 16B  is a perspective view showing the adaptor of the endoscope according to the twelfth embodiment of the present invention.  
       FIG. 16C  is a perspective view showing a flexible substrate of the adaptor of the endoscope according to the twelfth embodiment of the present invention.  
       FIG. 16D  is a side view showing a flexible substrate on which adaptor side electric contact points are arranged of the endoscope according to the twelfth embodiment of the present invention  
       FIG. 16E  and  FIG. 16F  are perspective views showing the distal end of the insertion portion of the endoscope according to the twelfth embodiment of the present invention.  
       FIG. 16G  is an enlarged sectional view showing a principal portion of the distal end of the insertion portion of the endoscope according to the twelfth embodiment of the present invention.  
       FIG. 16H  is an enlarged perspective view showing a principal portion of the distal end of the insertion portion of the endoscope according to the twelfth embodiment of the present invention.  
       FIG. 17A  is a longitudinal sectional view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to a thirteenth embodiment of the present invention.  
       FIG. 17B  is a perspective view showing a principal portion of the distal end of the insertion portion of the endoscope according to the thirteenth embodiment of the present invention.  
       FIG. 17C  is an explanatory diagram showing a balloon of the distal end of the insertion portion of the endoscope according to the thirteenth embodiment of the present invention when inflated.  
       FIG. 17D  is a sectional view showing the balloon of the distal end of the insertion portion of the endoscope according to the thirteenth embodiment of the present invention when inflated.  
       FIG. 18A  is a perspective view showing respectively an adaptor and a distal end of an insertion portion of an endoscope according to a fourteenth embodiment of the present invention.  
       FIG. 18B  is a front view seen from a proximal end side showing the adaptor of the endoscope according to the fourteenth embodiment of the present invention.  
       FIG. 18C  is a front view seen from a distal end side showing the distal end of the insertion portion of the endoscope according to the fourteenth embodiment of the present invention.  
       FIG. 19A  is a perspective view showing a flexible substrate provided for the adaptor of the endoscope according to the third embodiment of the present invention.  
       FIG. 19B  is a perspective view showing a flexible substrate provided for the adaptor of an endoscope according to another embodiment of the present invention.  
       FIG. 20A  is an exploded perspective view showing an endoscope according to another embodiment of the present invention.  
       FIG. 20B  is a perspective view showing the adaptor of an endoscope according to another embodiment of the present invention.  
       FIG. 20C  is a perspective view showing a distal end of an insertion portion of an endoscope.  
       FIG. 21  is a longitudinal sectional view showing the adaptor and the distal end of the insertion portion of the endoscope shown in  FIG. 20 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      A first embodiment according to the present invention is described, with reference to  FIG. 1A  to  FIG. 3B .  
      An endoscope  1  according to the present embodiment comprises, as the principal components thereof, an endoscope main body  3  comprising an elongated insertion portion  2 ; and a drum section  5  around which the insertion portion  2  of the endoscope main body  3  is wound to house it.  
      The endoscope main body  3  is housed inside a casing  6  that accommodates the drum section  5  allowing free rotation, and stored and transported therein.  
      The insertion portion  2  of the endoscope main body  3  comprises an elongated flexible-tube section  7  to be inserted into a lumen of a subject to be observed.  
      An adaptor (image pick up adaptor)  8  on which an electric device such as an illumination light souse is arranged, and a main body distal end section  10  which will be described later, to and from which another adaptor  8 A is attached and detached, are arranged on a distal end of the flexible tube section  7 .  
      The adaptor  8  is a so-called direct view type adaptor in which an objective lens  11  is arranged along a central axis C 1  direction of the adaptor  8  as shown in  FIG. 2A  to  FIG. 2C  and  FIG. 3A  and  FIG. 3B . The objective lens  11  is housed inside a lens cylinder section  12  formed in a substantially cylindrical shape, and it is housed in an outside member  16  formed in a cylindrical shape together with a LED unit (electrical device)  15  on which a plurality of LED chips  13  are arranged.  
      The lens cylinder section  12  comprises a thick cylindrically shaped base section  12 A and a cylinder wall  12 B that is arranged so as to project from a distal end surface  12   a  of the base section  12 A, and whose outer surface has a diameter smaller than that the outer surface of the base section  12 A and whose inner surface is formed so as to have an inner diameter substantially equal to the inner diameter of the base section  12 A. A depressed section  17  having a substantially D shaped cross-sectional shape is formed in a proximal end surface  12   b  of the base section  12 A. The depressed section  17  comprises a side surface section  18  comprising a first plane surface  18   a  that includes one portion of a line segment connecting two points on an outer circumferential surface of the base section  12 A, and of a first curved surface  18   b  that includes one portion of an arc along the outer circumferential surface, and a base section  20 .  
      A flange section  12   c  that projects outward in a radial direction is formed on a periphery section of the proximal end surface  12   b  of the base section  12 A. A connection ring  21  that is engaged with the lens cylinder section  12  so as to be freely rotatable around the central axis C 1 , is arranged on this flange section  12   c.  A female screw section  22  comprising a first female screw section  22 A and a second female screw section  22 B arranged along the central axis C 1 , is formed on an inner surface of the connection ring  21 .  
      The LED unit  15  comprises a flexible substrate  23  formed from soft material in a disc shape on which the plurality of LED chips  13  are mounted; and a thick disc shape aluminum substrate  25  that is formed from a metal material such as aluminum and supports the flexible substrate  23  within the lens cylinder  12 . The LED unit  15  is arranged fitted to the cylinder wall  12 B of the lens cylinder section  12 .  
      An insert hole  25   a  and a through hole  12   d  through which a pair of electric wires (only the anode side is shown in the diagram)  26 , one end of which is electrically connected to the flexible substrate  23 , is inserted substantially in parallel with the direction of the central axis C 1 , are arranged in the aluminum substrate  25  and the base section  12 A of the lens cylinder section  12 , respectively.  
      A pair of adaptor side terminal substrates  27  and  28  is respectively connected to the other end of the pair of the electric wires, and a pair of adaptor side electrode terminals  30  and  31  is arranged on the pair of adaptor side terminal substrates  27  and  28 , respectively.  
      The pair of adaptor side electrode terminals  30  and  31  is respectively arranged in a pair on the first plane surface  18   a  of the depressed section  17  of the lens cylinder section  12  via the pair of adaptor side terminal substrates  27  and  28 , in a direction orthogonal to the direction in which the adaptor  8  and insertion portion  2  attach and detach. This pair of adaptor side electrode terminals  30  and  31  is respectively comprising an adaptor side facing surface (facing surface)  32  that faces inward in the radial direction as a top surface of each of the terminals.  
      The main body distal end section  10  comprises a cylinder section  35  formed in a cylindrical shape on which a male screw section  33  is formed to be screwed into the female screw section  22  of the connection ring  21 . A prowling section  36  that is formed in a substantially D shaped cross-sectional shape and that fits into the depressed section  17  of the adaptor  8 , is arranged on a distal end side of the cylinder section  35 . The protruding section  36  comprises an insertion-portion-side side surface section  37  comprising a second plane surface  37   a  that faces the first plane surface  18   a  of the depressed section  17 , and a second curved surface  37   b  that faces the first curved surface  18   b  of the depressed section; and a distal end surface  38 .  
      A pair of insertion portion side terminal substrates  41  and  42  connected to an electric wire  40  (not shown) that extends from a power supply (such as a battery) in the drum section  5 , are arranged on the second plane surface  37   a  of the protruding section  36  of the main body distal end section  10 . A pair of insertion portion side electrode terminals  43  and  45  that come into contact respectively with the pair of adaptor side electrode terminals  30  and  31  to be electrically connected to the LED unit  15  when the insertion portion  2  is attached to the adaptor  8 , are arranged on the pair of insertion portion side terminal substrates  41  and  42 , respectively. Moreover, a CCD  46  that images an endoscopic subject via the objective lens  11 , is arranged on a central axis C 2  of the protruding section  36 .  
      The pair of insertion portion side electrode terminals  43  and  45  comprises an insertion portion side facing surface (facing surface)  47  that faces inward in the radial direction as a top surface of each of the terminals, so as to face the pair of adaptor side electrode terminals  30  and  31  when the adaptor  8  is attached.  
      A distance between the central axis C 2  and the insertion portion side facing surface  47  is substantially equal to the distance between the central axis C 1  and the adaptor side facing surface  32 , or, the distance to the insertion portion side facing surface  47  is slightly greater than that to the adaptor side facing surface  32 , so that the inert section side facing surface  47  and the adaptor side facing surface  32  can contact with each other.  
      An aligning section  48  that adjusts the orientation of the adaptor  8  so that the adaptor side facing surface  32  and the insertion portion side facing surface  47  face each other when the adaptor  8  is attached to the insertion portion  2  with the central axis C 1  and the central axis C 2  aligned on a same axis, is arranged on the first curved surface  18   b  of the depressed section  17  and on the second curved surface  37   b  of the protruding section  36 .  
      The aligning section  48  comprises a groove section  48 A arranged on the second curved space  37   b  of the protruding section  36  and a protruding engaging section  48 B arranged on the first curved surface  18   b  of the depressed section  17  so as to project inward in a radial direction to be engaged with the groove section. The respective terminal substrates are configured in pairs, as described for the pair of adaptor side terminal substrates  27  and  28  and the pair of insertion portion side terminal substrates  41  and  42 , however, two terminals may be arranged on an integrated terminal substrate instead of on the separate terminal substrates.  
      Next, the effects of using the endoscope  1  according to the present embodiment are described.  
      First, the protruding section  36  is inserted into the depressed section  17  with the engaging section  48 B of the depressed section  17  of the adaptor  8  engaged with the groove section  48 A of the protruding section  36 .  
      At this time, the adaptor side facing surfaces  32  of the pair of adaptor side electrode terminals  30  and  31  begin to come into contact with the insertion portion side facing surfaces  47  of the pair of insertion portion side electrode terminals  43  and  45 , and the area of their contact increases as insertion gradually progresses.  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  8  to bring the distal end surface  38  of the protruding section  36  into contact with a bottom section  20  of the depressed section  17  of the lens cylinder section  12 . At this time, the area of contact between the adaptor side facing surface  32  and the insertion portion side facing surface  47  reaches a maximum. Specifically, the pair of insertion portion side electrode terminals  43  and  45  is pressed against the pair of adaptor side electrode terminals  30  and  31  and they are brought in a close contact with each other. Therefore, the pair of adaptor side electrode terminals  30  and  31  is continuous with the pair of insertion portion side electrode terminals  43  and  45  so that the adaptor  8  and the main body distal end section  10  are electrically connected.  
      In this way, a predetermined observation is performed by inserting the insertion portion  2  into a lumen, which is a subject to be observed (not shown).  
      When the observation is finished, the insertion portion  2  is withdrawn from the lumen, and the connection ring  21  and main body distal end section  10  are unscrewed. At this time, the adaptor side facing surfaces  32  of the pair of adaptor side electrode terminals  30  and  31  begin to separate from the insertion portion side facing surfaces  47  of the pair of insertion portion side electrode terminals  43  and  45 , and the adaptor  8  and insertion portion  2  are electrically disconnected.  
      According to the endoscope  1 , the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  43  and  45  can be brought into surface-contact on their respective facing surfaces  32  and  47 , and the area of their contact can be successively increased from the start to the end of attachment. Therefore, the adaptor  8  and the insertion portion  2  can be electrically connected more reliably than in the case of line contact.  
      Here, the pair of adaptor side electrode terminal  30  and  31  and the pair of insertion portion side electrode terminals  43  and  45  are arranged side by side in a direction orthogonal to the direction of attachment and removal, on the first plane surface  18   a  and the second plane surface  37   a,  which have a normal line of different direction from that of the attachment and removal of the adaptor  8 . As a result, when attaching or detaching the adaptor  8 , the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  43  and  45  can be brought in contact at the same time, and wear of the terminals can be minimized for a reasonable number of times that the terminals come in contact.  
      Therefore, the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  43  and  45  can be brought in contact with a reliable contact-force even in the case of small size, and a reduction in the size of the insertion portion  2  and the adaptor  8  can be achieved.  
      Furthermore, since the aligning section  48  is provided, by attaching the insertion portion  2  to the adaptor  8  while positioning by the aligning section  48 , the respective facing surfaces  32  and  47  of the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  43  and  45  can be easily and reliably brought into contact.  
      Next, a second embodiment is described, with reference to  FIG. 4 .  
      Components similar to those in the first embodiment described above are given same reference symbols, and descriptions thereof are omitted.  
      The second embodiment differs from the first embodiment in that an adaptor side facing surface  32  of an adaptor side electrode terminal  30  (only the anode side is shown in the diagram) of a pair of adaptor side electrode terminals, and an insertion portion side facing surface  47  of an insertion portion side electrode terminal  43  (only the anode side is shown in the diagram) of a pair of insertion portion side electrode terminals, that an endoscope  50  according to the present embodiment has, are arranged so as to face each other in a direction angled at a predetermined angle α with respect to a central axis C of an adaptor  51  that is a direction in which an insertion portion  52  is attached to and removed from the adaptor  51 .  
      In a lens cylinder section  53  of the adaptor  51 , a first plane surface  56   a  of a side surface section  56  of a depressed section  55  formed in a proximal end surface  53   b  of a base section  53 A, is formed at an angle with the central axis C 1 , from a bottom section  20  of the depressed section  55  towards a proximal end section  53   b  of the base section  53 A so that a substantially D shaped cross-sectional shape successively becomes greater. The adaptor side electrode terminal  30  and a cathode side terminal (not shown) are arranged side by side in a direction orthogonal to the central axis C 1  on this first plane surface  56   a.    
      On the other hand, in order to maintain the adaptor side facing surface  32  and the insertion portion side facing surface  47  in a state of facing each other, a second plane surface  60   a  of an insertion-portion-side side surface  60  of a protruding section  58  of a main body distal end section  57  is formed at an angle with respect to the central axis C 2 , which is parallel with the central axis C 1 , so that a substantially D shaped cross-sectional shape successively becomes smaller towards an distal end surface  61  of the protruding section  58 .  
      Next, the procedures and effects when using the endoscope  50  according to the present embodiment is described.  
      First, as with the first embodiment, the protruding section  58  is inserted into the depressed section  51 , with the engaging section  48 B (see  FIG. 2 ) of the depressed section  55  of the adaptor  51  engaged with the groove section  48 A of the protruding section  58  of the main body distal end section  57 .  
      At this time, immediately after insertion has begun, since the first plane surface  56   a  and the second plane surface  60   a  are angled at the same angle with respect to the central axis C, the adaptor side facing surface  32  of the adaptor side electrode terminal  30  has not yet come into contact with the insertion portion side facing surface  47  of the insertion portion side electrode terminal  43 .  
      Then the male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  51  to bring the distal end surface  61  of the protruding section  58  into contact with the bottom section  20  of the depressed section  55 . At this time, since the distances from the central axis C to the adaptor side facing surface  32  and to the insertion portion side facing surface  47  are substantially equal, or, the distance to the insertion portion side facing surface  47  is slightly greater than the distance to the adaptor side facing surface  32 , an area of their contact successively increases from the moment the adaptor side facing surface  32  and the insertion portion side facing surface  47  begin to come in contact with each other until screwing in has been completed.  
      As described above, the area of contact reaches a maximum when screwing is complete, and the adaptor side electrode terminal  30  and the insertion portion side electrode terminal  43  are respectively conducted and the adaptor  51  and the main body distal end section  57  are electrically connected.  
      After that, as with the first embodiment, the insertion portion  52  is inserted into a lumen (not shown), which is a subject to be observed, to cry out a predetermined observation.  
      When the observation is finished, the insertion portion  52  is withdrawn from the lumen, and the connection ring  21  and main body distal end section  57  are unscrewed. At this time, the adaptor side facing surface  32  of the adaptor side electrode terminal  30  and the insertion portion side facing surface  47  of the insertion portion side electrode terminal  43  separate, and the adaptor  51  is electrically disconnected from the insertion portion  52 .  
      According to the endoscope  50 , even if the facing surfaces  32  and  47  of the adaptor side electrode terminals  30  and the insertion portion side electrode terminals  43  are not brought into contact at the beginning of attachment of the insertion portion  52  to the adaptor  51 , they can be brought into surface-contact when the adaptor  51  has been fully attached. Therefore, even if attachment and detachment of the adaptor  51  are repeatedly carried out, wear of the electrode terminals  30  and  43  can be suitably suppressed.  
      Next, a third embodiment is described, with reference to  FIG. 5A  to  5 C.  
      Components similar to those in the other embodiments described above are given same reference symbols, and descriptions thereof are omitted.  
      The third embodiment differs from the first embodiment in that a flexible substrate  72  in an adaptor  71  of an endoscope  70  according to the present embodiment comprises an extension section  7 A that is formed in a strip shape and extends from a distal end surface  73   a  side to a proximal end surface  73   b  along a side surface of a lens cylinder section  73 , and the pair of adaptor side electrode terminals  30  and  31  are arranged on a wiring pattern (not shown) formed on the extension section  72 A instead of on the pair of adaptor side terminal substrates  27  and  28 .  
      A depressed section  75  formed in the base section  73 A of the lens cylinder section  73  has a substantially circular shaped bottom section  76  having a diameter smaller than that of the base section  73 A, and a portion between a side surface section  77  and the outer circumferential surface of the base section  73 A forms a thin ring shaped wall section  78 .  
      A through hole  73   d  arranged in the base section  73 A is formed along the central axis C 1  so as to pass through the bottom section  76  in proximity to the side surface section  77  to the distal end surface  73   a  of the lens cylinder section  73 .  
      The through hole  73   d  is formed in a size that allows insertion of the extension section  72 A.  
      An engaging section of an aligning section (not shown) is arranged on the side surface section  77  of the depressed section  75 .  
      The flexible substrate  72  further comprises a disc section  72 B on which a LED chip  13  is arranged, and the extension section  72 A is formed so as to project from one portion of the disc section  72 B and it is bent so as to lie flexibly along a side surface of an aluminum substrate  80 . The pair of adaptor side electrode teals  30  and  31  is arranged in a line in a direction orthogonal to the central axis C 1  on a distal end section of the extension section  72 A, and they are electrically connected to the LED chip  13  arranged on the disc section  72 B via a wiring pattern (not shown).  
      The extension section  72 A has a substantially rectangular cross-sectional shape. As a result, since the side surface section  77  of the depressed section  75  of the lens cylinder section  73  is a curved surface and the side surface of the extension section  72 A is a plane surface, a gap  78 A is formed between the extension section  72 A and the through hole  73   d  when the extension section  72 A is inserted into the through hole  73   d.    
      No hole such as the insert hole  25   a  mentioned in the first embodiment is formed on the aluminum substrate  80 , instead, the outer diameter of the aluminum substrate  80  is formed to be substantially equal to that of the base section  73 A of the lens cylinder section  73 . A groove  80 A having a shape that allows the extension section  72 A of the flexible substrate  72  to be engaged and embedded in the aluminum substrate  80 , is formed in the side space of the aluminum substrate  80 .  
      A strip shaped insertion portion side flexible substrate  82  is connected to the electric wires  40  arranged on an insertion portion  81 , and a pair of insertion portion side electrode terminals  83  and  85  are arranged in a line on a distal end section of the insertion portion side flexible substrate  82 , in a direction orthogonal to the central axis C 2  direction.  
      A cylinder section  87  arranged on a main body distal end section  86  of the insertion portion  81  has an outer diameter that can be fitted into the depressed section  75 . A distal end surface  87   a  of the cylinder section  87  can be brought into contact with the bottom section  76  of the depressed section  75 . A cutaway section  88  of sufficient size to engage the extension section  72 A of the flexible substrate  72  and embed it into the cylinder section  87 , is formed in the side surface of the cylinder section  87 .  
      The cutaway section  88  is formed having a depth such that an end section  82   a  of the insertion portion side flexible substrate  82  extending within the cylinder section  87  can be mounted therein, and such that the distances from the central axis C to the adaptor side facing surface  32  and to the insertion portion side facing surface  47  are substantially equal, or, the distance to the insertion portion side facing surface  47  is slightly greater than the distance to the adaptor side facing surface  32 .  
      Next, the procedures and effects when using the endoscope  70  according to the present embodiment is described.  
      First, with the main body distal end section  86  being engaged with the adaptor  71  by the aligning section (not shown), the cylinder section  87  of the main body distal end section  86  is inserted into the connection ring  21 . At this time, as with the first embodiment, since the distances from the central axis C to the adaptor side facing surface  32  and to the insertion portion side facing surface  47  are substantially equal, or, the distance to the insertion portion side facing surface  47  is slightly greater than the distance to the adaptor side facing surface  32 , the adaptor side facing surface  32  and the insertion portion side facing surface  47  begin to come into contact with each other. Then, the distal end surface  87   a  of the cylinder section  87  and the bottom section  76  of the depressed section  75  of the lens cylinder section  73  are brought into contact with each other by screwing the male screw section  33  and the female screw section  22  together.  
      Since the pair of adaptor side electrode terminals  30  and  31  are arranged on the extension section  72 A of the flexible substrate  72  arranged along the side surface of the lens cylinder section  73 , when attaching the adaptor  71  the extension section  72 A elastically deforms outward in a radial direction within the gap  78 A when the pair of insertion portion side electrode terminals  83  and  85  has come into contact with the pair of adaptor side electrode terminals  30  and  31 .  
      Thus, the adaptor side facing surface  32  and the insertion portion side facing surface  47  come in contact with each other completely, with contact pressure between the facing surfaces  32  and  47  being adjusted by the elastic deformation of the extension section  72 A.  
      After that, the operation is similar to that in the first embodiment.  
      According to the endoscope  70 , effects similar to those achieved in the first embodiment can be achieved.  
      In particular, a frictional force that occurs between the facing surfaces  32  and  47  can be adjusted and the facing surfaces  32  and  47  can be brought into a more suitable contact condition.  
      Next, a fourth embodiment is described, with reference to  FIG. 6A  to  6 C.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The fourth embodiment differs from the third embodiment in that whereas the depressed section  75  is provided on the base section  73 A of the lens cylinder section  73  in the adaptor  71  of the endoscope  70  according to the third embodiment described above, on a base section  92 A of a lens cylinder section  92  in an adaptor  91  of an endoscope  90  according to the present embodiment, a support section  93  is arranged, having a plate width substantially equal to that of the extension section  72 A of the flexible substrate  72 , and being formed to project from a proximal end surface  92   b  of a lens cylinder section  92  and being bendable in a radial direction of the lens cylinder section  92 .  
      The support section  93  has a thickness that allows a gap between itself and an inner wall surface of the connection ring  21 , and is formed in a shape that allows it to be embedded in the cutaway section  88  arranged on the cylinder section  87  of the main body distal end section  86 .  
      A through hole  92   d  of the lens cylinder section  92  is formed not from a distal end surface  92   a  of the base section  92 A but from one portion of the side surface towards the proximal end surface  92   b  in the direction of the central axis C 1  within Me base section  92 A.  
      When inserted into the through hole  92   d,  the extension section  72 A of the flexible substrate  72  projects from the proximal end surface  92   b  and is supported by an inner surface of the support section  93 .  
      The engaging section of the aligning section (not shown) is arranged on an inner surface of the outside member  16 , and the groove section (not shown) is provided on the cylinder section  87  of the main body distal end section  86 .  
      The procedures and effects when using the endoscope  90  is described.  
      As with the third embodiment, the adaptor side facing surface  32  and the insertion portion side facing surface  47  begin to come into contact with each other. The the distal end surface  87   a  of the cylinder section  87  and the proximal end surface  92   b  of the base section  92 A of the lens cylinder section  92  are brought in contact with each other by screwing the male screw section  33  and the female screw section  22  together.  
      At this time, the support section  93  bends outward in a radial direction within the gap when the pair of insertion portion side electrode terminals  83  and  85  and the pair of adaptor side electrode terminals  30  and  31  have come in contact with each other on insertion of the adaptor  91 .  
      Thus, the adaptor side facing surface  32  and the insertion portion side facing surface  47  come in contact with each other completely, with contact pressure between the facing surfaces  32  and  47  being adjusted by the bending of the support section  93 .  
      After that, the operation is similar to that in the first embodiment.  
      According to the endoscope  90 , since the support section  93  is shorter than the wall section  78  in the crosswise direction with respect to the central axis C, and is easier to bend compared to the endoscope  70  according to the third embodiment, the extension section  72 A of the flexible substrate  72  can be deformed more suitably, and frictional force that occurs when the adaptor side facing surface  32  and the insertion portion side facing surface  47  are in contact, can be easily adjusted.  
      Next, a fifth embodiment is described, with reference to  FIGS. 7A and 7B .  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The fifth embodiment differs from the third and fourth embodiments in that a cylindrical shaped flexible substrate  103  to be electrically connected to a flexible substrate  102 , is arranged on an adaptor  101  of an endoscope  100 .  
      A proximal end surface  105   b  of a base section  105 A of a lens cylinder section  105  is a flat surface.  
      The length of an extension section  102 A of the flexible substrate  102  is substantially equal to the thickness of an aluminum substrate  80  in the direction of the central axis C 1 , and a pair of connection terminals  106  and  107  for LED chips  13 , is formed on an outer surface thereof.  
      The cylindrical shaped flexible substrate  103  is formed from a sheet substrate wrapped around in a cylindrical shape so as to cover the outer circumferential surfaces of the extension section  102 A and the lens cylinder section  105 . The length of the cylindrical shape flexible substrate  103  in the direction of the central axis C 1  is formed to be longer than the combined length of the aluminum substrate  80  and the lens cylinder section  105  when these are joined in the central axis C 1  direction. A pattern  108  that extends in the central axis C 1  direction and whose one end side contacts with a pair of connection terminals  106  and  107 , is arranged on an inner surface of the cylindrical shape flexible substrate  103 .  
      The pair of adaptor side electrode terminals  30  and  31  is arranged at the other end side of the wiring pattern  108 .  
      A flange section  110   a  with which the connection ring  21  engages, is arranged on a proximal end of an outside conductor  110 .  
      In a main body distal end section  111 , as with the case of the endoscope  1  according to the first embodiment, electric wires  40  are arranged to extend to the proximity of a distal end of a cylinder section  112 . On the side surface of the cylinder section  112  is arranged a cutaway section  113  in which the insertion portion side terminal substrate  41  on which the insertion portion side electrode terminal  43  is arranged, and a cathode side insertion portion side teal substrate (not shown) on which a cathode side insertion portion side electrode terminal (not shown) is arranged, can both be mounted along the circumferential direction of the side surface of the cylinder section  112 .  
      The procedures and effects when using the endoscope  100  is described.  
      As with the first embodiment, the adaptor side facing surface  32  and the insertion portion side facing surface  47  begin to come into contact with each other. Then, the distal end surface  112   a  of the cylinder section  112  and the proximal end surface  105   b  of the base section  105 A of the lens cylinder section  105  are brought in contact with each other by screwing the male screw section  33  and the female screw section  22  together.  
      At this time, the insertion portion side electrode terminal  43  and the adaptor side electrode terminal  30  begin to come into contact with each other in the direction of the central axis C, and the adaptor side facing surface  32  and the insertion portion side facing surface  47  come into contact with each other completely.  
      Thus, the adaptor  101  is electrically connected to the main body distal end section  111 .  
      According to the endoscope  100 , since the operation of the cylindrical shape flexible substrate  103  according to the present embodiment is similar to that of the wall section  78  of the lens cylinder section  105  according to the third embodiment, an operation and effect similar to that of the endoscope  70  according to the third embodiment can be achieved.  
      Next, a sixth embodiment is described, with reference to  FIG. 8A  to  8 C.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The sixth embodiment differs from the third embodiment in that a rubber member (biasing device)  123  is arranged on a main body distal end section  121  of an endoscope  120  according to the present embodiment, fitted to a cylinder wall  126  formed to project from a distal end surface  125   a  of a cylinder section  125 , to successively increase a pressing pressure between the adaptor side electrode terminal (only the anode side is shown in the diagram)  30  of the pair of adaptor side electrode terminals, and the insertion portion side electrode terminal  83  of the pair of insertion portion side electrode terminals  83  and  85  when the adaptor  71  is attached to an insertion portion  122 .  
      The rubber member  123  is formed in a sectional D shape having a first side surface  123   a  formed from a flat surface and a second side surface  123   b  formed from an arc surface having a diameter substantially equal to that of the cylinder section  125 , and a hole  123   c  to which the cylinder wall  126  of the cylinder section  125  is fitted is arranged in a central section of the rubber member  123 .  
      A distal end surface  123   d  of the rubber member  123  is arranged so as to project slightly from the distal end of the cylinder section  125  of the main body distal end section  121  when the rubber member  123  is fitted to the cylinder wall  126 .  
      An end section  82   a  of an insertion portion side flexible substrate  82  is mounted on the fist side surface  123   a  of the rubber member  123 . At this time, the distance from the central axis C to an insertion portion side facing surface  47  is substantially equal to the distance from the central axis C to an adaptor side facing surface  32 .  
      Next, the procedures and effects when using the endoscope  120  according to the present embodiment is described.  
      First, the cylinder section  125  of the main body distal end section  121  is inserted into the connection ring  21  and the outside member  16  of the adaptor  71  until the distal end surface  123   d  of the rubber member  123  has come in contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  73 .  
      At this time, the insertion portion side facing surface  47  and the adaptor side facing surface  32  are opposed to each other, however, they are not yet in contact with each other.  
      Then, the male screw section  33  of the main body distal end section  121  is screwed together with the female screw section  22  of the connection ring  21 .  
      At this time, a compressive force in the central axis C direction is loaded onto the rubber member  123 , and the rubber member  123  is elastically deformed outward in the radial direction by a resistance force from the cylinder section  125 , so that the outer diameter of the rubber member  123  increases. As a result, the distance from the central axis C to the insertion portion side facing surface  47  changes as the insertion portion side facing surface  47  moves outward in the radial direction. Then, the insertion portion side facing surface  47  begins to come into contact with the adaptor side facing surface  32 .  
      In this way, the area of contact successively increases by the time screwing has been completed and the area of contact reaches a maximum when screwing has been completed, and the adaptor  71  and the insertion portion  122  are electrically connected.  
      According to the endoscope  120 , the area of contact between the adaptor side electrode terminal  30  and the insertion portion side electrode terminal  83  can be increased by deforming the rubber member  123  outward in the radial direction by pressing the rubber member  123 , and each of the corresponding facing surfaces  32  and  47  can be reliably brought into contact with each other. At this time, since the insertion portion side facing surface  47  does not come in contact with the adaptor side facing surface  32  unless the rubber member  123  is compressed, wear in the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be suitably suppressed.  
      Next, a seventh embodiment is described, with reference to  FIG. 9A and 9B .  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The seventh embodiment differs from the third embodiment in that a plate spring section (biasing device, spring member)  133  that is bent in the radial direction to give a pressing force, is arranged in a lens cylinder section  132  in an adaptor  131  of an endoscope  130  according to the present embodiment.  
      The plate spring section  133  is formed by cutting out one portion of a side surface  132   e  along the central axis C 1  from a distal end surface  132   a  of a base section  132 A of the lens cylinder section  132  to a proximal end surface  132   b.  Meanwhile, a hole section  132   f  is formed in the side surface  132   e  of the lens cylinder section  132  where the plate spring section  133  has been cut out. The plate spring section  133  can bend in the radial direction within the hole section  132   f.    
      An end section  133   a  of the plate spring section  133  is formed so as to project into the depressed section  75 .  
      An extension section  135   a  of the flexible substrate  135  is arranged along the outer circumferential surface of the plate spring section  133  and the extension section  135   a  is fixed by being folded back at the end section  133   a  of the plate spring section  133 .  
      The adaptor side electrode terminal  30  (only the anode side is shown in the diagram) is arranged on a top surface of the extension section  135   a  folded back into the depressed section  75 .  
      A disc section  135 B of the flexible substrate  135  is arranged on the distal end surface  132   a  of the base section  132 A of the lens cylinder section  132  and not on an aluminum substrate.  
      On an inner surface of an outside member  136 , a depressed section  136 A is formed to ensure that the range regulated by the outside member  136  allows at least a bending movement in the case where the plate spring section  133  bends and deforms.  
      A sheet elastic body  137  is arranged between the insertion portion side flexible substrate  82  and the cutaway section  88  in the main body distal end section  86 . The thickness of this elastic body  137  is adjusted so that the distance from the central axis C to the adaptor side facing surface  32  becomes shorter than the distance from the central axis C to the insertion portion side facing surface  47 , to a degree that the adaptor  131  can be attached to the main body distal end section  86 .  
      Next, the procedures and effects when using the endoscope  130  according to the present embodiment is described.  
      First, the cylinder section  87  of the main body distal end section  86  is inserted into the depressed section  75  of the adaptor  131  along the aligning section (not shown).  
      At this time, the adaptor side facing surface  32  of the adaptor side electrode terminal  30  begins to come into contact with the insertion portion side facing surface  47  of the insertion portion side electrode terminal  83 . At this time, since a radial direction outward force is loaded onto the adaptor side electrode terminal  30  from the insertion portion side electrode terminal  83 , the plate spring section  133  bends outward in the radial direction within the hole section  132   f,  with the adaptor side facing surface  32  and the insertion portion side facing surface  47  in contact with each other.  
      Meanwhile, since the inward force in the radial direction is loaded onto the inset section side electrode terminal  83  from the adaptor side electrode terminal  30 , the insertion portion side flexible substrate  82  bends inward in the radial direction, compressing the elastic body  137 .  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  131  to bring the distal end space  87   a  of the cylinder section  87  into contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  132 . At this time, the end section  133   a  of the bent plate spring section  133  comes in contact with the depressed section  136 A of the outside member  136 . Then, a radial direction inward force acts on it from the outside member  136 .  
      Therefore, a constant force is maintained, and the area of contact between the adaptor side facing surface  32  and the insertion portion side facing surface  47  is maintained constant, and the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are respectively conducted and the adaptor  131  and the main body distal end section  86  are electrically connected.  
      According to the endoscope  130 , the area of contact between the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be successively increased while adjusting the force by deforming the plate spring section  133  when attaching the adaptor, and wear of the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be suitably suppressed.  
      Next, an eighth embodiment is described, with reference to  FIGS. 10A and 10B .  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The eighth embodiment differs from the seventh embodiment in that adaptor side electrode terminals  142  (only the anode side is shown in the diagram) of a pair of adaptor side electrode terminals in an adaptor  141  of an endoscope  140  according to the present embodiment, are formed as plate spring elastic members, and an adaptor side facing surface  143  is arranged at a constant angle α with respect to the central axis C.  
      The adaptor side electrode terminal  142  is formed connected to the extension section  135 A of the flexible substrate  135  and is bent back in the inward radial direction to a constant angle α with respect to the extension section  135 A of the flexible substrate  135 . A space section  142 A is formed at the folding back portion.  
      An engaging groove  146  having a predetermined length along the central axis C 1  from a distal end surface  145   a  towards a proximal end surface  145   b  is arranged in one portion of a side surface  145   e  of a base section  145 A of a lens cylinder section  145 . This engaging groove  146  has a cross-sectional shape into which the extension section  135 A of the flexible substrate  135  can be fitted and embedded. A hole section  145   f  through which the adaptor side electrode terminal  142  arranged on the end section of the extension section  135 A can pass from the outer surface of the lens cylinder section  145  to the side surface section  77 , is formed in an end section  146   a  of the engaging groove  146 .  
      The adaptor side facing surface  143  of the adaptor side electrode terminal  142  and the inset section side facing surface  47  of the insertion portion side electrode terminal  83  do not oppose each other until the adaptor  141  has been attached.  
      Next, the procedures and effects when using the endoscope  140  according to the present embodiment is described.  
      First, the cylinder section  87  of the main body distal end section  86  is inserted into the depressed section  75  of the adaptor  141  along the aligning section (not shown).  
      At this time, the adaptor side facing surface  143  and the insertion portion side facing surface  47  begin to come in contact with each other. At this time, a radial direction outward force is loaded onto the adaptor side electrode terminal  142 , and at first, the extension section  135 A of the flexible substrate  135  bends and deforms outward in the radial direction.  
      As attachment proceeds further, the extension section  135 A of the flexible substrate  135  comes into contact with the depressed section  136 A of the outside member  136  and stops deforming. Thereafter, the adaptor side electrode terminal  142  elastically deforms in a direction in which the space section  142 A becomes smaller. The area of contact between the adaptor side facing surface  143  and the insertion portion side facing surface  47  of the insertion portion side electrode terminal  83  successively increases, and the adaptor side electrode terminal  142  and the insertion portion side electrode terminal  83  become substantially parallel with each other.  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  141  to bring the distal end surface  87   a  of the cylinder section  87  into contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  145 . At this time, the adaptor side facing surface  143  and the insertion portion side facing surface  47  oppose to and come in contact with each other with the area of contact between them maintained constant, and the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are respectively conducted and the adaptor  141  and the main body distal end section  86  are electrically connected.  
      According to the endoscope  140 , by attaching the adaptor  141  to the main body distal end section  86  and deforming the pair of the plate spring adaptor side electrode terminals, the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be brought in contact with each other while increasing the area of contact between them, and wear of both of them can be suitably suppressed.  
      As shown in  FIG. 11A , a pair of insertion portion side electrode terminals  150  and  151  may be formed in a form of a plate spring that is angled at a constant angle α with respect to the central axis C. At this time, as shown in  FIG. 11B , adaptor side electrode terminals  152  and  153  may be formed as metal bodies with the adaptor side facing surfaces  143  opposing to the insertion portion side facing surfaces  47  at the constant angle α with respect to the central axis C.  
      Next, a ninth embodiment is described, with reference to  FIGS. 12A and 12B .  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The ninth embodiment differs from the eighth embodiment in that in an adaptor  161  of an endoscope  160  according to the embodiment, an extension section  162 A and a disc section  162 B of a flexible substrate  162 , are separated from each other and they are both connected by a pair of electric wires  163  and  165 .  
      A plate spring section  166  folded back inward in the radial direction at a constant angle α with respect to the central axis C 1 , is connected to a proximal end of the extension section  162 A. A space section  166 A is formed in a portion where the plate spring section  166  is folded back. An end section side of the extension section  162 A of the flexible substrate  162  is folded back along the plate spring section  166 .  
      The pair of adaptor side electrode terminals  30  and  31  is arranged on a surface of an end section  162   a  of the extension section  162 A that has been folded back to face inward in the radial direction.  
      According to the endoscope  160 , since the pair of adaptor side electrode terminals  30  and  31  are arranged on a top surface of the plate spring section  166  connected to the flexible substrate  162 , and the extension section  162 A and the disc section  162 B are connected to the pair of the electric wires  163  and  165 , an operation and effect similar to that of the eighth embodiment can be achieved.  
      Furthermore, instead of connecting the flexible substrate  162  and the plate spring section  166  with the pair of the electric wires  163  and  165 , as shown in  FIGS. 13A and 13B , the proximal end side of the extension section  162 A may be folded back inward in the radial direction and a flexible substrate  167  having a plate spring extension section  167 A may be provided, while the disc section  162 B of the flexible substrate  162  is left as it is.  
      Next, a tenth embodiment is described, with reference to  FIG. 14A  to  14 C.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The tenth embodiment differs from the the embodiment in that an insertion portion side flexible substrate  172  of a main body distal end section  171  of an endoscope  170  according to the present embodiment is arranged on a distal end of a cylinder section  173 .  
      The insertion portion side flexible substrate  172  comprises a disc section  172 A formed in a disc shape through which electric wires  40  that extend through the cylinder section  173  can pass, and a terminal section  172 B that extends from one portion of the periphery of the disc section  172 A at a constant angle with respect to the central axis C 2 . The disc section  172 A and the terminal section  172 B are integrally formed, and the terminal section  172 B can bend like a plate spring with respect to the disc section  172 A. The pair of insertion portion side electrode terminals  83  and  85  are arranged on a top surface of the terminal section  172 B.  
      An insertion portion side depressed section  175  that can accommodate the insertion portion side flexible substrate  172  is formed in a distal end surface  173   a  of the cylinder section  173  of the main body distal end section  171 . The insertion portion side depressed section  175  comprises a bottom section  176  and a side surface section  177  as is the case with the depressed section  75  of the adaptor  71 , and a second cutaway section  179  for directly connecting the bottom section  176  and the cutaway section  178  is formed in one portion of the side surface section  177 . Furthermore, a groove section of an aligning section (not shown) is formed in the side surface section  177  of tie insertion portion side depressed section  175 .  
      Next, the procedures and effects when using the endoscope  170  according to the present embodiment is described.  
      First, the cylinder section  173  of the main body distal end section  171  is inserted into the depressed section  75  of the adaptor  71  along the aligning section (not shown).  
      At this time, the insertion portion side facing surface  47  and the adaptor side facing surface  32  of the adaptor side electrode terminal  30  (only the anode side is shown in the diagram) begin to come in contact with each other. At this time, since a radial direction inward force is loaded onto the insertion portion side electrode terminal  83 , the pair of insertion portion side electrode terminals  83  and  85  are pressed inward in the radial direction. Therefore, the terminal section  172 B of the insertion portion side flexible substrate  172  bends in a direction along the central axis C, and an area of contact between the insertion portion side facing surface  47  and the adaptor side facing surface  32  increases as they become substantially parallel.  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  71  to bring the distal end surface  173   a  of the cylinder section  173  into contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  73 . At this time, the adaptor side facing surface  32  and the insertion portion side facing surface  47  oppose to and come in contact with each other with the area of contact between them maintained constant, and the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are respectively conducted, and the adaptor  71  and the main body distal end section  171  are electrically connected.  
      According to the endoscope  170 , since the pair of insertion portion side electrode terminals  83  and  85  are arranged on the terminal section  172 B of the insertion portion side flexible substrate  172  that deforms like a plate spring with respect to the disc section  172 A, by attaching the adaptor  71  to the main body distal end section  171  and deforming the terminal section  172 B, the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be brought into contact with each other while gradually increasing an area of contact between them, and wear of them can be suitably suppressed.  
      Next, an eleventh embodiment is described, with reference to  FIG. 15A  to  15 F.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The eleventh embodiment differs from the third embodiment in that an insertion portion side flexible substrate  182  of a main body distal end section  181  of an endoscope  180  according to the present embodiment is arranged so as to be folded back at a distal end of a cylinder section  183 , as shown in  FIG. 15A .  
      As shown in  FIGS. 15B and 15C , the insertion portion side flexible substrate  182  is formed in a rectangular plane plate shape and comprises a first side surface  182   a  that is arranged to be in contact with the cylinder section  183  and upon which a wiring pattern  185  to be connected to the electric wires  40  is formed so as to extend to its distal end side; and a second side surface  182   b  that is a side surface opposite to the first side surface  182   a  and is arranged facing the outward radial direction of the cylinder section  183 .  
      As shown in  FIG. 15D , the distal end side of the insertion portion side flexible substrate  182  is folded back towards the first side surface  182   a  side in a direction angled at a constant angle α with respect to the central axis C 2 , and creates a space section  182 A, and can elastically deform until the first side surface  182   a  comes into contact with itself.  
      The pair of insertion portion side electrode terminals  83  and  85  is arranged on the second side surface  182   b  so as to be separated from the distal end of the wiring pattern  185  by a predetermined distance as shown in  FIG. 15E . First contact points  187  that correspond to the respective electrode terminals  83  and  85  are arranged in positions on the first side surface  182   a  where the pair of insertion portion side electrode terminals  83  and  85  are arranged.  
      Second contact points  188  that face the first contact points  187  when the distal end side of the insertion portion side flexible substrate  182  is folded back, are arranged on the distal end of the wiring pattern  185 .  
      A conductive rubber sheet (biasing device, rubber member)  189  that has a conducting property in a pressed direction when pressed, is arranged in the space section  182 A formed when the distal end section of the insertion portion side flexible substrate  182  is folded back, as shown in  FIG. 15E .  
      The conductive rubber  189  here is constructed with conductive members such as nickel particles or gold plated metal particles or the like embedded in a dotted pattern in an insulating rubber material such as silicone rubber, and it is generally referred to as a dot type anisotropic conductive rubber and so forth. In this conductive rubber  189 , when the rubber material, which is an elastic body, is pressed in a thickness direction, a conducting property between the conductive members increases as they become highly dense due to compressive deformation of the rubber material and thereby conduction in the thickness direction is allowed. At this time, since the rubber material is an insulating member, insulation in directions other than the thickness direction of the rubber material (for example, the circumferential direction) is still maintained.  
      Next, the procedures and effects when using the endoscope  180  according to the present embodiment is described.  
      First, the cylinder section  183  of the main body distal end section  181  is inserted into the depressed section  75  of the adaptor  71  shown in  FIG. 15F  along the aligning section (not shown).  
      At this time, the insertion portion side facing surfaces  47  of the pair of insertion portion side electrode terminals  83  and  85  and the adaptor side facing surfaces  32  of the pair of adaptor side electrode terminals  30  and  31  begin to come in contact with each other.  
      At this time, since a radial direction inward force is loaded onto the folded-back distal end portion of the insertion portion side flexible substrate  182 , the distal end portion deforms in a direction which becomes substantially parallel with the central axis C 2 , making the space section  182 A smaller. Then, the conductive rubber  189  is sandwiched by the first contact points  187  and the second contact points  188 , and compressed and deformed.  
      As a result, a degree of contact between the conductive rubber  189  and the wiring pattern  185 , and contact between the conductive rubber  189  and the pair of insertion portion side electrode terminals  83  and  85  increases, and the conducting property of the conductive rubber  189  in the radial direction increases to electrically connect the pair of insertion portion side electrode terminals  83  and  85  and the wiring pattern  185 .  
      At the same time, the area of contact between the insertion portion side facing surface  47  and the adaptor side facing surface  32  successively increases.  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  71  to bring the distal end surface  183   a  of the cylinder section  183  into contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  73 . At this time, the adaptor side facing surface  32  and the insertion portion side facing surface  47  oppose to and come in contact with each other with the area of contact between them maintained constant, and the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  83  and  85  are conducted, respectively, and the adaptor  71  and the main body distal end section  181  are electrically connected.  
      According to the endoscope  180 , when the pair of insertion portion side electrode terminals  83  and  85  are electrically connected with the wiring pattern  185  of the same insertion portion side flexible substrate  182 , by pressing to deform the conductive rubber  189  in response to the attachment of the adaptor, the condition of electrical connection between the pair of insertion portion side electrode terminals  83  and  85  and the wiring pattern  185  can be gradually improved.  
      Meanwhile, since the conductive rubber  189  elastically deforms while the adaptor  71  is being attached to the main body distal end section  181 , then as with the seventh embodiment, the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  83  and  85  can gradually be brought in contact with each other while the area of their contact gradually increases and wear of both of them can be suitably suppressed.  
      Next, a twelfth embodiment is described, with reference to  FIG. 16A  to  16 G.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The twelfth embodiment differs from the eleventh embodiment in that a pair of adaptor side electrode terminals  192  and  193  of an adaptor  191  of an endoscope  190  according to the present embodiment shown in  FIGS. 16A and 16B  are formed as coil springs (elastic members), the diameters of which become smaller towards the inside in the radial direction, and are arranged on the extension section  72 A of the flexible substrate  72  as shown in  FIGS. 16C and 16D .  
      A cutaway depressed section  198  is formed inward in the radial direction on a top surface of a cutaway section  197  formed in a cylinder section  196  of a main body distal end section  195  as shown in  FIGS. 16E and 16F .  
      A distal end of an insertion portion side flexible substrate  200  is arranged so as to project from a proximal end side of an insertion portion  201  into the cutaway depressed section  198 .  
      As shown in  FIG. 16G , a conductive rubber  202  is mounted in the cutaway depressed section  198 . A pair of metal plates  203  and  205  are arranged on this conductive rubber  202  as shown in  FIG. 16H , with the middle portion of the plates folded back at the distal end of the conductive rubber  202 , one end of the inward radial direction side of the plates being in contact with the wiring pattern  185  of the insertion portion side flexible substrate  200 , and the other end of the outward radial direction side of the plates having the pair of insertion portion side electrode terminals  83  and  85  arranged thereon. In other words, the pair of insertion portion side electrode terminals  83  and  85  and the insertion portion side flexible substrate  200  can be electrically brought in contact with each other via the pair of the metal plates  203  and  205  and the conductive rubber  202 .  
      The thickness of the conductive rubber  202  when it is not compressed is adjusted so that the distance between the pair of insertion portion side electrode terminals  83  and  85  and the central axis C 2  is greater than the distance between the central axis C 1  and the distal end section  206  of the adaptor side electrode terminals  192  and  193 , and shorter than the distance from the central axis C 1  to an attachment surface of the pair of adaptor side electrode terminals  192  and  193 .  
      Next, the procedures and effects when using the endoscope  190  according to the present embodiment is described.  
      First, the cylinder section  196  of the main body distal end section  195  is inserted into the deposed section  75  of the adaptor  191  along the aligning section (not shown), and the pair of insertion portion side electrode terminals  83  and  85  and the pair of adaptor side electrode terminals  192  and  193  begin to come into contact with each other.  
      A radial direction inward force from the pair of insertion portion side electrode terminals  83  and  85  is loaded onto the pair of adaptor side electrode terminals  192  and  193 , causing them to compress and deform. At this time, since the coil diameters of the pair of adaptor side electrode terminals  192  and  193  become successively smaller, the area of their contact with the pair of insertion portion side electrode terminals  83  and  85  successively increases as they are compressed.  
      Meanwhile, the pair of insertion portion side electrode terminals  83  and  85  receives a radial direction inward pressing force from the pair of adaptor side electrode terminals  192  and  193 . As a result, the conductive rubber  202  is compressed in the plate thickness direction via the pair of the metal plates  203  and  205 , and the pair of the metal plates  203  and  205  is pressed to the insertion portion side flexible substrate  200  side. Thus, while the area of their contact successively increases, the conducting property of the conductive rubber  202  in the compression direction increases.  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  191  to bring the distal end surface  196   a  of the cylinder section  196  into contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  73 . At this time, the area of contact between the pair of adaptor side electrode terminals  192  and  193  and the pair of insertion portion side electrode terminals  83  and  85  reaches a maximum, and the adaptor  191  and the main body distal end section  195  are electrically connected.  
      According to the endoscope  190 , as with the eleventh embodiment, the pair of insertion portion side electrode terminals  83  and  85  comes into electrical contact with the wiring pattern  185  of the insertion portion side flexible substrate  200  via the conductive rubber  202 , and their contact condition can be gradually improved. At this time, since the pair of adaptor side electrode terminals  192  and  193  itself elastically deforms, the area of contact between the pair of adaptor side electrode terminals  192  and  193  and the pair of insertion portion side electrode terminals  83  and  85  can be more smoothly increased while they are brought in contact with each other.  
      Next, a thirteenth embodiment is described, with reference to  FIG. 17A  to  17 D.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The thirteenth embodiment differs from the third embodiment in that a balloon (biasing device)  215  that bends the distal end side of the insertion portion side flexible substrate  82  exposed in a cutaway section  213  in the radial direction when it is supplied with air/air is removed to inflates it/deflate it, is arranged in the cutaway section  213  arranged in a cylinder section  212  of a main body distal end section  211  of an endoscope  210  according to the present embodiment as shown in  FIG. 17A .  
      The distal end section of the insertion portion side flexible substrate  82  is mounted on the balloon  215 . An air tube  216  for supplying air to or removing supplied air from the balloon  215 , is arranged along the electric wires  40  within an insertion portion  217 , one end of the air tube being connected to the balloon  215  and the other end connected to an air source (not shown).  
      The procedures and effects when using The endoscope  210  is described.  
      First, the cylinder section  212  of the main body distal end section  211  is inserted into the depressed section  75  of the adaptor  71  along the aligning section (not shown). At this time, the insertion portion side electrode terminal  83  on the anode side of the pair of insertion portion side electrode terminals  83  and  85  is not yet in contact with the adaptor side electrode terminal  30  of the pair of adaptor side electrode terminals (only the anode side is shown in the diagram).  
      The male screw section  33  is screwed into the female screw section  22  of the connection ring  21  of the adaptor  71  to bring the distal end surface  212   a  of the cylinder section  212  in contact with the bottom section  76  of the depressed section  75  of the lens cylinder section  73 , and air from an air source (not shown) is introduced into the air tube  216  and is supplied into the balloon  215 .  
      At this time, as shown in  FIG. 17B  to  FIG. 17D , the balloon  215  begins to expand outward in the radial direction, and the distal end section of the insertion portion side flexible substrate  82  mounted on the balloon  215  bends as a curved surface along the expanded surface of the balloon  215 . Then the insertion portion side electrode terminal  83  moves outward in the radial direction to press the adaptor side electrode terminal  30  outward in the radial direction. As a result, the area of contact between the insertion portion side electrode terminal  83  and the adaptor side electrode terminal  30  successively increases.  
      Thus, the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are respectively conducted with each other and the adaptor  71  and the main body distal end section  211  are electrically connected.  
      According to the endoscope  210 , an effect similar to that of the other embodiments in which the electrode terminals are biased in the radial direction by a spring member can be achieved. In particular, since a biasing force is given to the balloon  215  by supplying it with air, the performance of the biasing device can be maintained for a longer period of time compared to the case of providing a constant biasing device.  
      Next, a fourteenth embodiment is described, with reference to  FIG. 18A  to  18 C.  
      Components similar to those in the other embodiments described above are given the same reference symbols, and descriptions thereof are omitted.  
      The fourteenth embodiment differs from the third embodiment in that a pair of adaptor side electrode terminals  30  and  31  in an adaptor  221  of an endoscope  220  according to the present embodiment, is arranged side by side in the radial direction from the outer circumferential surface of the adaptor  221  towards the central axis C 1  as shown in  FIGS. 18A and 18B , and a pair of insertion portion side electrode terminals  83  and  85  arranged on a main body distal end section  222  are also arranged side by side in the same direction.  
      That is, an extension section  223 B of a flexible substrate  223  is formed so as to project from a disc section (not shown) towards the proximal end side taking the radial direction of the disc section as a crosswise direction. Then, on side surfaces of an aluminum substrate (not shown) and a base section  226  of a lens cylinder section  225 , instead of a through hole, a slit (not shown) is arranged, that respectively engages with the extension section  223 B to stop the extension section  223 B from projecting from the outer surface when arranged so that the crosswise direction of the extension section  223 B substantially matches the radial direction of the side surfaces of the aluminum substrate and the base section  226  of the lens cylinder section  225 .  
      A support section  230  that projects inward in the radial direction to support the extension section  223 B projecting from the slit, is arranged on a side surface section  228  of a depressed section  227  of the lens cylinder section  225 . At this time, the adaptor side facing surfaces  32  of the pair of adaptor side electrode terminals  30  and  31  are arranged to face in the circumferential direction of the lens cylinder section  225 .  
      As shown in  FIG. 18C , an engaging groove  232  into which the support section  230  can be inserted, is formed on the side surface of the cylinder section  231  at the main body distal end section  222 , from the side surface towards the inside in the radial direction. Then, when the adaptor  221  is attached to the main body distal end section  222 , the insertion portion side flexible site  233  is arranged on a side surface  232   a  of the engaging groove  232  so that the pair of adaptor side electrode terminals  30  and  31  faces the pair of insertion portion side electrode terminals  83  and  85 .  
      Here, the width of the engaging groove  232  is sufficient for the adaptor side facing surfaces  32  of the pair of adaptor side electrode terminals  30  and  31  and the insertion portion side facing surfaces  47  of the pair of insertion portion side electrode terminals  83  and  85  to come into contact with each other when the adaptor  221  is attached with the pair of insertion portion side electrode terminals  83  and  85  arranged on the side surface  232   a.    
      The endoscope  220  is not comprising the aligning section seen in the respective embodiments mentioned above, and the support section  230  has a function as an engaging section, and the engaging groove  232  has a function as a groove section.  
      Next, the procedures and effects when using the endoscope  220  according to the present embodiment is described.  
      First, with the support section  230  of the adaptor  221  being engaged in the engaging groove  232  of the main body distal end section  222 , the cylinder section  231  of the main body distal end section  222  is inserted into the connection ring  21 .  
      At this time, the adaptor side facing surface and the insertion portion side facing surface begin to come in contact with each other, and the area of their contact increases with insertion as they gradually come into contact in the attachment direction.  
      Then, the distal end surface  231   a  of the cylinder section  231  and the bottom section  235  of the depressed section  227  of the lens cylinder section  225  are brought into contact with each other by screwing the male screw section  33  and the female screw section  22  together.  
      At this time, the area of contact between the adaptor side facing surface  32  and the insertion portion side facing surface  47  reaches a maximum, and the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  83  and  85  are conducted, respectively, and the adaptor and the main body distal end section  222  are electrically connected.  
      According to the endoscope  220 , the pair of adaptor side electrode terminals  30  and  31  and the pair of insertion portion side electrode terminals  83  and  85  can be brought into surface contact on their respective facing surfaces, and the area of their contact can be successively increased from the start to the end of attachment. Therefore, the adaptor  221  and the main body distal end section  222  can be electrically connected more reliably than in the case of line contact.  
      Moreover, since an aligning section is not provided, the number of parts can be reduced and assembly can be improved.  
      The technical range of the present invention is not limited to the embodiments mentioned above, and various modifications may be made without departing the scope of the invention.  
      For example, in the third embodiment described above, when the extension section  72 A of the flexible substrate  72  is pressed outward in the radial direction, the extension section  72 A moves in the radial direction within the gap  78 A formed between the extension section  72 A and the side sake section  77  of the depressed section  75  of the lens cylinder section  73 . However, in the case where the extension section is formed from a soft member, the gap may be filled in with an adhesive agent.  
      In this case, since one portion part way along the extension section bends, instead of the end section of the extension section moving in the radial direction when attached, the degree of this bend adjusts the pressure of contact between the pair of adaptor side electrode terminals and the pair of the insertion portion side electrode terminals, and an effect similar to that of the above embodiments can be achieved.  
      Moreover, in the space section  166 A of the plate spring section  166  arranged on the flexible substrate  162  according to the above ninth embodiment shown in  FIG. 19A , as shown in  FIG. 19B , an elastic body (biasing device)  240  may be arranged, angled at a constant angle.  
      In this case, the pair of insertion portion side electrode terminals (not shown) can be pressed by an elastic force that occurs when the elastic body  240  deforms with deformation of the plate spring section  166 , and the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals can be brought into contact with each other more reliably as a result.  
      Furthermore, in the above embodiments, the pair of adaptor side electrode terminals and the pair of insertion portion side electrode terminals are respectively arranged in pairs in a direction orthogonal to the direction in which the adaptor and the insertion portion are attached to each other. However, arrangement of the electrode terminals is not limited to the direction described above, and it may be a direction substantially the same as the direction in which the adaptor and the insertion portion are attached to each other. For example, as shown in  FIG. 20A ,  FIG. 20B  and  FIG. 21 , the pair of adaptor side electrode terminals  251  and  252  of an endoscope  250  may be arranged on the flexible substrate  162  according to the above ninth embodiment along a direction orthogonal to the central axis C, which is a direction in which an adaptor  253  and a main body distal end section  255  are attached to each other. In this case, on the main body distal end section  255 , a pair of insertion portion side electrode terminals  257  and  258  is arranged on one insertion portion side terminal substrate  256  arranged on the second plane surface of the protruding section  36  so as to respectively face the pair of insertion portion side electrode terminals  251  and  252 .  
      Moreover, as shown in  FIG. 20C , a pair of insertion portion side electrode terminals  261  and  262  of a main body distal end section  260  may be arranged in a line in a direction diagonal to the central axis C 2 . In this case, the pair of adaptor side electrode terminals (not shown) is also arranged diagonally so as to face the pair of insertion portion side electrode terminals  261  and  262 .  
      While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.