Abstract:
An endoscope device includes an objective lens group that is provided at a distal end of an insertion portion that is inserted into a lumen of a subject and is used to observe or photograph the subject, and an illumination device that is provided at a distal end of the insertion portion and illuminates the subject using LED. The illumination device is provided with LED chips and an LED chip supporting block that supports these LED chips, and at least a portion of the objective lens group is mounted on the LED supporting block.

Description:
PRIORITY CLAIM 
     This application is continuation application of a PCT Application No. PCT/JP2005/011634, filed on Jun. 24, 2005, entitled “endoscope device” whose priority is claimed on Japanese Patent Application No. 2004-189288, filed Jun. 28, 2004. The contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an endoscope device having an objective lens group and an LED-based illumination device provided on an insertion portion that is inserted into the lumen of a subject. 
     2. Description of Related Art 
     In endoscope devices that are used in medicine and industry, an objective lens group that is used for observation or for image pickup, and an illumination device that is used to light up the area around a subject inside a lumen are provided at a distal end of an insertion portion that is inserted into the lumen. A device that irradiates light from an externally located light source onto a subject via an optical fiber is widely used for the illumination device, however, in recent years, devices have been developed in which light emitting diodes (referred to below as LED) are directly mounted on the insertion portion, and the area around the subject is lit by light from these LED (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2002-562). 
     In this conventional endoscope device, an objective lens group and a lens adaptor that incorporates LED are removably fitted onto a distal end of the insertion portion, and the plurality of lenses that make up the objective lens group are mounted on a lens supporting block inside the lens adaptor. LED chips are mounted on a front surface of a metal LED supporting block that is shaped like a circular plate with a hole in it, and this LED supporting block is fixed in position by being fitted onto an outer circumference of a circular cylindrical wall that stands upright on the lens supporting block. 
     SUMMARY OF THE INVENTION 
     The endoscope device of the present invention includes: an objective lens group that is provided at a distal end of an insertion portion that is inserted into a lumen of a subject and is used to observe or photograph the subject; and an illumination device that is provided at a distal end of the insertion portion and illuminates the subject using LED. The illumination device is provided with LED chips and an LED chip supporting block that supports these LED chips. At least a portion of the objective lens group is mounted on the LED supporting block. 
     In the endoscope device of the present invention, it is also possible for objective lenses of the objective lens group, excluding the objective lenses that are mounted on the LED supporting block, to be provided on a separate lens supporting block, and for the LED supporting block to be provided such that it can be mounted on or removed from a front surface of the lens supporting block. 
     In the endoscope device of the present invention, it is also possible for the LED supporting block to be connected to the lens supporting block via a positioning device. 
     In the endoscope device of the present invention, it is also possible for an electrical connection portion that is formed by a recess and protrusion engagement for supplying power to the LED chips to be provided between the LED supporting block and the lens supporting block, and the positioning device is formed by the recess and protrusion engagement structure of the electrical connection portion. 
     In the endoscope device of the present invention, it is also possible for the entire objective lens group to be mounted on the LED supporting block. 
     In the endoscope device of the present invention, it is also possible for a lens adaptor that is provided with the LED chips and the LED supporting block to be provided at a distal end of the insertion portion main body of the insertion portion, and for the lens adaptor to be provided with: a substantially cylindrical outer cylinder portion that is placed at a front end portion and through which is inserted the LED supporting block; a substantially cylindrical connecting portion that is inserted through the outer cylinder portion and is fixed to a rear end portion of the outer cylinder portion; and a substantially cylindrical connecting ring that is mounted on the connecting portion so as to be freely rotatable, and that connects the LED supporting block to a distal end of the insertion portion main body such that it can be freely attached thereto and removed therefrom, and for a threaded portion that is screwed onto a distal end of the insertion portion main body to be formed on the connecting ring. 
     In the endoscope device of the present invention, it is also possible for an abutting wall portion that protrudes inwards to be provided at a front end portion of the outer cylindrical portion and, when the LED supporting block is inserted from a rear end portion of the outer cylindrical portion, for a front end portion of the LED supporting block that is positioned at the front in the insertion direction of the LED supporting block to abut against the abutting wall portion. 
     In the endoscope device of the present invention, it is also possible for the LED supporting block to be formed integrally with the outer cylinder portion. 
     In the endoscope device of the present invention, it is also possible for a stopper flange that protrudes inwards in a radial direction to be formed at a front end portion of the outer cylinder portion, and for the stopper flange to abut against a placement surface for the LED chips that is located on a front surface of the LED supporting block. 
     In the endoscope device of the present invention, it is also possible for the placement surface for the LED chips that is located on the front surface of the LED supporting block to be positioned so as to protrude from a front end portion of the outer cylinder portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal cross-sectional view of principal portions illustrating a first embodiment of the present invention. 
         FIG. 2A  is a perspective view showing a state in which the endoscope device of the first embodiment has been disassembled. 
         FIG. 2B  is a perspective view showing a state in which the endoscope device of the first embodiment has been assembled and housed. 
         FIG. 3  is an exploded perspective view of principal portions illustrating the first embodiment. 
         FIG. 4A  is a perspective view of principal portions illustrating the first embodiment. 
         FIG. 4B  is a perspective view of principal portions illustrating a variant example of the first embodiment. 
         FIG. 5  is an exploded perspective view illustrating a second embodiment of the present invention. 
         FIG. 6  is an exploded perspective view illustrating a third embodiment of the present invention. 
         FIG. 7  is a longitudinal cross-sectional view of principal portions illustrating a fourth embodiment of the present invention. 
         FIG. 8  is an exploded perspective view illustrating a fourth embodiment of the present invention. 
         FIG. 9  is an exploded perspective view illustrating a fifth embodiment of the present invention. 
         FIG. 10  is a longitudinal cross-sectional view of principal portions illustrating a sixth embodiment of the present invention. 
         FIG. 11  is an exploded perspective view illustrating a sixth embodiment of the present invention. 
         FIG. 12  is a longitudinal cross-sectional view of principal portions illustrating a seventh embodiment of the present invention. 
         FIG. 13  is an exploded perspective view illustrating a seventh embodiment of the present invention. 
         FIG. 14  is a longitudinal cross-sectional view of principal portions illustrating an eighth embodiment of the present invention. 
         FIG. 15  is a perspective view illustrating an eighth embodiment of the present invention. 
         FIG. 16  is an exploded perspective view illustrating an eighth embodiment of the present invention. 
         FIG. 17  is a longitudinal cross-sectional view of principal portions illustrating a ninth embodiment of the present invention. 
         FIG. 18  is a perspective view illustrating a ninth embodiment of the present invention. 
         FIG. 19  is a longitudinal cross-sectional view of principal portions illustrating a tenth embodiment of the present invention. 
         FIG. 20  is a perspective view illustrating a tenth embodiment of the present invention. 
         FIG. 21  is an exploded perspective view illustrating a tenth embodiment of the present invention. 
         FIG. 22  is a longitudinal cross-sectional view of principal portions illustrating an eleventh embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Next, each of the embodiments of the present invention will be described based on the drawings. Note that in the descriptions of the respective embodiments below, the same descriptive symbols are used for identical components and a repeated description thereof is omitted. 
     Firstly, the first embodiment shown in  FIGS. 1 to 4B  will be described. 
     An overall schematic structure of an endoscope device according to the present invention is shown in  FIGS. 2A and 2B . As is shown in these drawings, this endoscope device is provided with an insertion portion  3 , and a box-shaped device main body  5  that houses the insertion portion  3 . A direct-view type of lens adaptor  2  is removably connected to a distal end of a long flexible tube (i.e., an insertion portion main body)  1  of the insertion portion  3 . The flexible tube  1  of the insertion portion  3  is wound onto a drum  4  and this drum  4  is rotatably housed in the device main body  5 . The device main body  5  housing the drum  4  is stored inside a storage case  6  used for carrying the endoscope device. 
     This endoscope device has a CCD (not shown) provided as an image pickup device at a distal end of the insertion portion  3 , and image signals captured by this CCD pass along a signal wire inside the flexible tube  1  and are output to a signal processing circuit (not shown) that is incorporated in the device main body  5 . Signals that have been processed by this signal processing circuit are then projected as video images on an image display unit such a liquid crystal panel or the like. Note that, in addition to the signal processing circuit, a main power supply circuit (not shown) that is connected to a battery power supply and the like are also incorporated in the device main body  5 . 
     As is described above, the lens adaptor  2  is provided at the distal end of the flexible tube  1  in the insertion portion  3  that is inserted into a lumen. More specifically, a connecting plug  9  that is formed from a hard material such as metal is provided at a distal end of the flexible tube  1 , and the lens adaptor  2  is removably provided at a distal end portion of this connecting plug  9 . The aforementioned CCD is provided at the distal end portion of the connecting plug  9  as well as electrodes  10   a  and  10   b  (see  FIG. 1 ) that supply current to the lens adaptor  2 .  FIG. 2  shows a replacement lens adaptor  2 A and a storage pocket  7  in which the lens adaptor  2 A is stored. An insertion portion main body of the insertion portion  3  is formed by portions excluding the lens adaptor  2 , namely, by the flexible tube  1  and the connecting plug  9  and the like. 
     As is shown in  FIGS. 1 and 3 , in the lens adaptor  2 , a lens supporting block  12  and an LED supporting block  13  are housed inside a substantially circular cylinder-shaped adaptor housing (i.e., an outer cylinder portion)  11  so as to be superposed in an axial direction thereof. The overall shape of the lens supporting block  12  is formed substantially as a thick circular cylinder, and principal constituent lenses of an objective lens group  14  (hereinafter, these constituent lenses are called a “first lens group  14   a ”) are housed in an inner circumferential portion thereof. The LED supporting block  13  is formed as a circular plate having a hole therein and having the same outer diameter as the lens supporting block  12 . A plurality of LED chips  15  (LED bare chips in this embodiment) are mounted on a front surface of the LED supporting block  13  via a thin non-conductive plate-shaped component  16 , and the remaining constituent lenses (hereinafter, these constituent lenses are called a “second lens group  14   b ”) of the objective lens group  14  are housed in an inner circumferential portion of the LED supporting block  13 . This LED supporting block  13  is fixed to a front surface of the lens supporting block  12  by an adhesive or the like. Note that the lens supporting block  12  and the LED supporting block  13  are formed from a metal material having excellent thermal conductivity such as aluminum or the like. Moreover, examples of an adhesive agent that may be used as the aforementioned adhesive include silicon having excellent thermal conductivity and a conductive adhesive agent containing metal powder. 
     The non-conductive plate-shaped component  16  is formed having substantially the same shape as the front surface of the LED supporting block  13 , and a pair of electrodes  17   a  and  17   b  are embedded in this front surface. In addition, a plurality of LED chips  15  are mounted thereon in a toroidal shape. Front surfaces of the two electrodes  17   a  and  17   b  lie exposed from the non-conductive plate-shaped component  16 , and are joined by wire bonding to the plurality of LED chips  15  that are mounted on the non-conductive plate-shaped component  16 . Wires  18   a  and  18   b  are respectively connected to the electrodes  17   a  and  17   b , and each of these wires  18   a  and  18   b  extend rearward along guide grooves  19  and  20  that are formed on outer surfaces of the LED supporting block  13  and the lens supporting block  12 . Note that, although not shown in the drawings, suitable sealing glass is installed onto the front surface of the LED supporting block  13  including the LED chips  15 . 
     As is shown in  FIG. 1 , a small diameter cylindrical wall  22  stands upright from a rear surface of the lens supporting block  12 , and an electrode substrate  23  in the shape of a circular plate having a hole therein as well as conductive rubber  24  are fitted onto an outer circumference of the cylindrical wall  22 . As is shown in  FIGS. 3 and 4A , a pair of through holes  25   a  and  25   b  that penetrate in the plate thickness direction are formed in the electrode substrate  23 , while a pair of conductor patterns  21   a  and  21   b  that form an electrode are formed on a rear surface of the electrode substrate  23 . As is shown in  FIG. 4A , the respective conductor patterns  21   a  and  21   b  extend so as to curve gently inwards in a radial direction from a portion close to an outer side in the radial direction where the through holes  25   a  and  25   b  are formed. End portions of the respective wires  18   a  and  18   b  are soldered to the respective conductor patterns  21   a  and  21   b  via the corresponding through holes  25   a  and  25   b . Note that, as is shown in  FIG. 4B , it is also possible for the conductor patterns  21   a  and  21   b  to extend from the through hole  25   a  and  25   b  portions directly inwards in the radial direction, and from there to extend in an arc shape that is concentric with the inner circumferential surface of the electrode substrate  23 . A rear conductive rubber  24  is pressed against the respective conductive patterns  21   a  and  21   b.    
     The conductive rubber  24  is formed by embedding conductive components such as nickel particles or gold plated metal particles in a non-conductive rubber material such as silicon rubber in a dotted pattern. Normally, this is known as a dot type of anisotropic conductive rubber or the like. Because the conductive rubber  24  has the above described structure, if the rubber material, which is an elastic object, is pressed in the thickness direction thereof, the conductivity between conductive components whose density has been increased by the resulting compression deformation increases so that conductivity in the thickness direction is allowed. However, because the rubber material is a non-conductive component, a non-conductive state is maintained at this time in directions other than the thickness direction (for example, the circumferential direction) of the rubber material. 
     As is described below, when the lens adaptor  2  is connected, the conductive rubber  24  is pressed from the rear by the electrodes  10   a  and  10   b  of the connecting plug  9 . As a result, only those localized portions that are pressed by the respective electrodes  10   a  and  10   b  become conductive so that only the electrodes of the electrode substrate  23  and the connecting plug  9  that are located in positions facing each other at this time become electrically connected. 
     A substantially circular-cylinder shaped guide component (i.e., joining portion)  26  that protrudes rearwards from the adaptor housing  11  is provided protruding at a rear end portion of the lens supporting block  12 . An enlarged diameter cylindrical wall  27  whose diameter is enlarged in a step shape is formed integrally with a rear portion of this guide component  26 . A circular cylinder-shaped connecting ring  28  is fitted to this enlarged diameter cylindrical wall  27  such that it can be displaced in an axial direction and in a pivot direction. An inward protruding stopper flange  29  against which the step portion of the enlarged diameter cylindrical wall  27  is able to abut is formed integrally with one end portion of the connecting ring  28 . Moreover, a first female thread (i.e., threaded portion)  30  and a second female thread (i.e., threaded portion)  31  are provided a predetermined distance apart in the axial direction on an inner circumferential surface of the connecting ring  28 . 
     Note that, as is shown in  FIGS. 1 and 3 , with the connecting ring  28  placed inside it the guide component  26  is fixed together with a spacer ring  36  by a screw  37  to an inner surface of a rear portion of the adaptor housing  11 . At this time, a front end surface of the guide component  26  is pressed against the rear surface of the electrode substrate  23 . In addition, an inwardly protruding stopper flange  38  is formed at a front end portion of the adaptor housing  11 , and the front end portion of the LED supporting block  13 , which is assembled as a single unit together with the lens supporting block  12  and the electrode substrate  23 , is prevented from being withdrawn by this stopper flange  38 . Accordingly, all three of the LED supporting block  13 , the lens supporting block  12 , and the electrode substrate  23  are sandwiched between the stopper flange  38  and the guide component  26  and, in this state, are fixed inside the adaptor housing  11 . Moreover, as is shown in  FIG. 3 , recessed grooves  33  are formed in a front end portion of the guide component  26  in order to prevent it making contact with the soldered portions on the conductor patterns  21   a  and  21   b.    
     In contrast, a male thread  32  used for fixing is formed on an outer circumferential surface of the connecting plug  9 . By screwing the first female thread  30  and the second female thread  31  of the connecting ring  28  in sequence onto the male thread  32 , the lens adaptor  2  can be connected to the connecting plug  9 . Namely, if the connecting ring  28  of the lens adaptor  2  is screwed onto the front end portion of the connecting plug  9  and if, in this state, the connecting ring  28  is rotated in a predetermined direction, then any displacement in the axial direction of the connecting ring  28  is restricted by the stopper flange  29  abutting against the step portion of the enlarged diameter cylindrical wall  27 . In this state, the male thread  32  of the connecting plug  9  is fastened in sequence into the first female thread  30  and then the second female thread  31 , and the electrodes  10   a  and  10   b  that protrude from the front end surface of the connecting plug  9  press against the conductive rubber  24  so as to become electrically connected to the conductor patterns  21   a  and  21   b  on the electrode substrate  23  via the conductive rubber  24 . Note that, after the male thread  32  of the connecting plug  9  has been screwed into the second female thread  31 , the engagement thereof with the first female thread  30  is undone, however, the first female thread  30  functions as a stopper to prevent the connecting plug  9  falling out in the unlikely event that the engagement becomes undone between the male thread  32  and the second female thread  31 . 
     The symbols  34  and  35  in  FIG. 1  denote a positioning protrusion and a receiving groove that are formed respectively in the guide cylinder  27  and the connecting plug  9  and that position both  27  and  9  in the rotation direction by engaging with each other. 
     In the endoscope device of the present embodiment, as in the structure described above, the objective lens group  14  that is located on an axial center portion of the lens adaptor  2  is separated into a first lens group  14   a  and a second lens group  14   b , and the second lens group  14   b  is directly mounted on the axial center portion of the LED supporting block  13 . Accordingly, compared with a structure in which the LED supporting block  13  is screwed onto an outer circumference of a separate component housing the objective lens group  14 , it is possible to more easily secure the space needed to position the LED chips  15  on the front surface of the LED supporting block  13 . As a result, it is possible to reduce the outer diameter of the LED supporting block  13  and achieve a reduction in the diameter of the lens adaptor  2  (i.e., the distal end of the insertion portion) without altering the diameter of the objective lens which would affect the optical characteristics. 
     Moreover, in this endoscope device, because the objective lens group is separated and placed on a lens supporting block and an LED supporting block, if necessary, it is possible to separate the lens adaptor  2  and change the combination of the lens supporting block  12  and the LED supporting block  13 . Namely, in this embodiment, it is possible to remove the guide component  26  and the spacer ring  36  from the rear portion of the adaptor housing  11  by undoing the screw  37 , and, in this state, all three of the LED supporting block  13 , the lens supporting block  12 , and the electrode substrate  23  can be removed as a single block from the adaptor housing  11 . Furthermore, by melting the soldered portions or the like, it is possible to replace the LED supporting block  13  or the lens supporting block  12  for ones having different specifications. If only the LED supporting block  13  is to be replaced, then if a plurality of LED supporting blocks  13  are prepared in advance in which the optical characteristics (i.e., the focal length and angle of view and the like) and light distribution characteristics of the objective lens (i.e., the second lens group  14   b ) and the LED chips  15  have been combined so as to be optimally matched, it becomes possible to deal flexibly and easily with a variety of observation specifications. 
     Furthermore, because the connecting ring  28  is mounted on the guide component  26  such that it can rotate freely, when the connecting ring  28  is rotated and the LED supporting block  13  is connected to the distal end of the flexible tube  1 , the LED supporting block  13  and the lens supporting block  12  and the like are not rotated with the connecting ring  28 . Accordingly, the LED supporting block  13  and the lens supporting block  12  can be easily positioned at the distal end of the flexible tube  1 . 
     In the endoscope device of this first embodiment no special positioning structure is provided for the LED supporting block  13  and lens supporting block  12  themselves, and when bonding the two together, the axial centers of the two are made to conform to each other using a jig or the like. However, as in a second embodiment shown in  FIG. 5 , it is also possible to provide positioning projections  40  on one of an LED supporting block  113  and a lens supporting block  112 , and to provide engaging holes  41  that engage with the projections  40  on the other of the two supporting blocks  113  and  112 . When this type of structure is employed, it is possible to easily and reliably align the axial centers of the two supporting blocks  113  and  112  without having to use a dedicated jig or the like. Note that, in this embodiment, the positioning projection  40  and engaging hole  41  constitute a positioning device. 
       FIG. 6  shows a third embodiment of the present invention. In this embodiment, an LED supporting block  213  and a lens supporting block  212  are joined together using a plurality of axially elongated connecting pins  50 . The respective connecting pins  50  are inserted through pin holes  51  that penetrate a non-conductive plate-shaped component  216  and the LED supporting block  213  in the axial direction, and distal end portions thereof that have penetrated the pin holes  51  are screwed into threaded holes  52  in the lens supporting block  212 . In the case of this endoscope device, it is possible using the connecting pins  50  to simultaneously align the axial centers of the LED supporting block  213  and the lens supporting block  212  and also fix the two supporting blocks  213  and  212  together. As a result, compared with when the supporting blocks  213  and  212  are adhered together, there is a huge improvement in the workability of the assembly task. Furthermore, when replacing the LED supporting block  213  and lens supporting block  212  with other supporting blocks, this can be achieved simply by unscrewing the connecting pins  50  so that the replacement task also has a high level of workability. Note also that, in this embodiment, the connecting pins  50 , the pin holes  51 , and the threaded holes  52  constitute a positioning device. 
     Next, a fourth embodiment shown in  FIGS. 7 and 8  will be described. 
     In the endoscope device of this embodiment, the basic structure in which a portion of the objective lenses  14  (i.e., the second lens group  14   b ) is directly mounted on an inner circumferential portion of the LED supporting block  13  and the remaining objective lenses (i.e., the first lens group  14   a ) are mounted on the lens supporting block  12  is the same as in the first embodiment, however, a device that enables the LED supporting block  13  to be easily mounted on or removed from the lens supporting block  12  is further employed. 
     The adaptor housing  311  is separated into a rear portion housing  311   a  that has the guide component  26  mounted on a rear end portion thereof and houses the lens supporting block  12  and the electrode substrate  23  and the like inside it, and a front portion housing  311   b  that is located forward of the rear portion housing  311   a  and houses the LED supporting block  13  and the like inside it. In addition, electrode substrates  60  and  61  are fixed by adhesive respectively to the front surface of the lens supporting block  12  and the rear surface of the LED supporting block  13 , and electrode portions of these electrode substrates  60  and  61  are connected together via a recess and protrusion engagement. 
     Namely, on the electrode substrate  61  on the LED supporting block  13  side, are formed a pair of protruding electrodes  62   a  and  62   a  that protrude rearwards and through holes  63   a  and  63   b  that penetrate in the thickness direction. Wires  18   a  and  18   b  that are drawn forwards from in front of the LED supporting block  13  pass through the through holes  63   a  and  63   b  are connected to the protruding electrodes  62   a  and  62   b . The respective protruding electrodes  62   a  and  62   b  are formed as circular columns that extend in the axial direction of the electrode substrate  61 . In contrast, on the electrode substrate  60  on the lens supporting block  12  side are provided a pair of recessed electrodes  64   a  and  64   b , and wires  318   a  and  318   b  that are drawn from the electrode substrate  23  to the rear are connected to these recessed electrodes  64   a  and  64   b . The recessed electrodes  64   a  and  64   b  are formed at positions corresponding to the protruding electrodes  62   a  and  62   b , and are able to be engaged with the protruding electrodes  62   a  and  62   b  when the axial centers of the lens supporting block  12  and the LED supporting block  13  are aligned. As a result, in this embodiment, the protruding electrodes  62   a  and  62   b  are respectively connected to the recessed electrodes  64   a  and  64   b  by a recess and protrusion engagement. 
     In the endoscope device of this embodiment the same basic operation and effects as those of the first embodiment can be obtained, however, because a structure is employed in which the adaptor housing  311  is separated into a front portion housing  311   a  and a rear portion housing  311   b , and the front portion housing  311   a  can be fitted to and removed from the rear portion housing  311   b , the LED supporting block  13  can be easily replaced from the front surface of the adaptor housing  311 . In particular, in this embodiment, because power is supplied to the LED chips  15  by the recess and protrusion engagement structure formed by the protruding electrodes  62   a  and  62   b  and the recessed electrodes  64   a  and  64   b , it is not necessary for any solder to first be melted before they are removed or fitted. Accordingly, there is a considerable improvement in the workability of the task of replacing the LED supporting block. Moreover, because the recess and protrusion engagement structure formed by the protruding electrodes  62   a  and  62   b  and the recessed electrodes  64   a  and  64   b  also contributes to the positioning that is performed in order to align the axial centers of the LED supporting block  13  and the lens supporting block  12 , it is possible for the apparatus structure to be simplified due to it no longer being necessary to provide a separate positioning portion. 
     Moreover, in all of the embodiments described above, the objective lens group is separated into a first lens group on the lens supporting block side and a second lens group on the LED supporting block side and these lens groups are each mounted on their respective block, however, as in a fifth embodiment shown in  FIG. 9 , it is also possible to form an LED supporting block  413  as a thick circular cylinder and to mount all of the lens elements of the objective lens group  14  in an inner circumferential portion of the LED supporting block  413 . If this type of structure is employed, it is possible to reduce the number of components due to it no longer being necessary to place a separate lens supporting block at a rear portion of the LED supporting block  413 , and there is also an improvement in the workability of the assembly task. 
     Furthermore, as in the aforementioned fifth embodiment, when all of the lens elements (i.e., the first lens group  14   a  and the second lens group  14   b ) of the objective lens group  14  are mounted in an inner circumferential portion of the LED supporting block  413 , by employing a structure in which the LED supporting block  413  and a guide component are inserted from the same direction into a substantially circular cylinder-shaped adaptor housing, it becomes possible to form the LED supporting block and the guide component as a single unit. 
     Namely, as in the sixth embodiment shown in  FIGS. 10 and 11 , it is also possible for a substantially circular cylinder-shaped guide portion (i.e., connecting portion)  453  that has the same outer diameter as an LED supporting block  451  to be formed integrally with the LED supporting block  451  and protruding from a rear end portion thereof. A toroidal step portion  455  is formed on a rear end portion of the guide portion  453  so as to protrude outwards in a radial direction from an outer circumferential surface thereof and abut against the stopper flange  29  of the connecting ring  28 . 
     In this structure, a stopper flange (i.e., abutting wall portion)  459  is formed extending inwards in a radial direction on an inner circumferential surface at a position slightly down from a front end portion of an adaptor housing (i.e., an outer cylindrical portion)  457 . When the LED supporting block  451  is inserted from a rear end portion of the adaptor housing  457 , this stopper flange  459  performs the function of abutting against a front end portion of the LED supporting block  451  that is positioned at the front in the insertion direction. 
     This structure will now be described in more detail. A placement surface of the LED chips  15  that have been placed at a front surface of the LED supporting block  451  abuts against the stopper flange  459  of the adaptor housing  457 . Namely, of the non-conductive plate-shaped component  16  that is mounted on a front surface of the LED supporting block  451 , the front surface thereof where the LED chips  15  are located abuts against the stopper flange  459 . 
     As has been described above, by forming the guide portion  453  integrally with the LED supporting block  451 , the number of constituent components of the lens adaptor  452  can be reduced, thereby allowing a reduction in the production costs of the lens adaptor  452  to be achieved and enabling the task of assembling the lens adaptor  452  to be performed easily. Moreover, because it is possible for heat generated from the LED chips  15  to be released to the flexible tube  1  via only two components, namely, the LED supporting block  451  and the connecting ring  28 , heat discharge from the LED chips  15  can be performed efficiently. 
     When this type of structure is employed, because the LED chips  15  are placed further to the front of the adaptor housing  457  than the stopper flange  459  which protrudes inwards in a radial direction, it is possible to prevent any light from the LED chips  15  being blocked by the stopper flange  457 . Accordingly, light can be irradiated over a wide angle by the LED chips  15 . 
     In the structure of this sixth embodiment, a small-diameter cylindrical wall  461  is formed protruding from an inner circumferential edge of a front surface of the LED supporting block  451 , and the non-conductive plate-shaped component  16  is placed on the front surface of the LED supporting block  451  with this cylindrical wall  461  in a state of being inserted in the hole in the non-conductive plate-shaped component  16 . Furthermore, a large-diameter cylindrical wall  463  is formed on the adaptor housing  457  so as to protrude forward beyond the stopper flange  459 . Accordingly, a substantially toroidal recessed portion  465  that is bounded by the pair of cylindrical walls  461  and  463  and by the non-conductive plate-shaped component  16 , and a recessed portion  467  that is bounded by the cylindrical wall  461  of the LED supporting block  451  and the second lens group  14   b  may be filled with a transparent resin or a transparent cover glass may be placed thereon so that the second lens group  14   b  and the LED chips  15  can be protected by the resin or cover glass. 
     In the above described first through fifth embodiments, a pair of wires that supply current to the LED chips  15  are placed at point symmetrical positions on the outer circumferential surface of the LED supporting blocks (see  FIGS. 1 and 3 ), however, as in the sixth embodiment shown in  FIGS. 10 and 11 , it is also possible for a pair of wires  469   a  and  469   b  to be positioned adjacent to each other. 
     Namely, a pair of electrodes  471   a  and  471   b  that are electrically connected to the plurality of LED chips  15  are embedded in the non-conductive plate-shaped component  16  so as to be adjacent to each other. Moreover, the wires  469   a  and  469   b  are connected respectively to the two electrodes  471   a  and  471   b , and each of these wires  469   a  and  469   b  are inserted through a pair of through holes  473   a  and  473   b  that penetrate from a front end portion of the LED supporting block  451  to a rear end portion thereof. The respective wires  469   a  and  469   b  are connected respectively to electrode substrates  475   a  and  475   b  that are provided at a rear end portion of the through holes  473   a  and  473   b , and adaptor electrodes  477   a  and  477   b  that are made from an elastically deformable metal are connected respectively to a rear portion of each of the electrode substrates  475   a  and  475   b.    
     In this structure, in order to supply current to a plurality of LED chips  15 , it is sufficient simply to press the respective adaptor electrodes  477   a  and  477   b  using a pair of electrodes that are provided adjacent to each other at a distal end portion of the connecting plug  9 . 
     In all of the above described embodiments the LED supporting block is inserted from the rear end portion of the adaptor housing, however, the present invention is not limited to this and it is also possible for the LED supporting block to be inserted from a front end portion of the adaptor housing. Namely, as in the seventh embodiment shown in  FIGS. 12 and 13 , it is possible to form a male thread  503  on an outer circumferential surface of an LED supporting block  501 , and to form a female thread  507  on an inner circumferential surface located at a front end position of an adaptor housing (i.e., an outer cylindrical portion)  505 . By then screwing the male thread  503  and the female thread  507  together, the LED supporting block  501  may be mounted on the adaptor housing  505 . Note that, in this structure, a guide component  508  is inserted from a rear end portion of the adaptor housing  505 . 
     A large-diameter step portion  509  that abuts against a front end surface of the adaptor housing  505  is formed on an outer circumferential surface of the LED supporting block  501 . Accordingly, by screwing together the male thread  503  and the female thread  507 , and also causing the step portion  509  to abut against the adaptor housing  505 , relative positioning between the LED supporting block  501  and the adaptor housing  505  can be performed. 
     Moreover, this step portion  509  is located further to the rear in an axial direction than a placement surface of the LED supporting block  501  where the non-conductive plate-shaped component  16  is placed, namely, the placement surface of the LED supporting block  501  is located further to the front than the front end surface of the adaptor housing  505 . Accordingly, the adaptor housing  505  that is located on the outer side in the radial direction of the LED supporting block  501  does not block the light from the LED chips  15 , and it becomes possible to irradiate light from the LED chips  15  over a wide angle. 
     In the structure of the seventh embodiment, a small-diameter cylindrical wall  511  is formed protruding from an inner circumferential edge of a front surface of the LED supporting block  501 , and a large-diameter cylindrical wall  513  is formed protruding from an outer circumferential edge of the same front surface. Accordingly, in the same way as in the case of the sixth embodiment, a substantially toroidal recessed portion  515  that is bounded by the pair of cylindrical walls  511  and  513  and by the non-conductive plate-shaped component  16 , and a recessed portion  517  that is bounded by the small-diameter cylindrical wall  511  and the second lens group  14   b  may be filled with a transparent resin or a transparent cover glass may be placed thereon so that the second lens group  14   b  and the LED chips  15  can be protected by the resin or cover glass. 
     Note that, as in this seventh embodiment, when a structure is employed in which the LED supporting block  501  and the guide component  508  are inserted into the adaptor housing  505  from different directions, then the adaptor housing  505  may be formed integrally with the LED supporting block  501 . In this case, it is possible to reduce the number of constituent components of the lens adaptor  519  so that a reduction in production costs of the lens adaptor  519  can be achieved and the task of assembling the lens adaptor  519  can be performed easily. Furthermore, in this case, because components on which the LED chips  15  are mounted, such as the non-conductive plate-shaped component  16  and the LED supporting block  501 , are exposed to the outside, the effect is achieved that heat from the LED chips  15  can be efficiently discharged to the outside. 
       FIGS. 14 to 16  show the eighth embodiment of the present invention. In the endoscope device of this embodiment, the basic structure of the present invention is applied to a side-view type of lens adaptor  551 . In the lens adaptor  551  of this endoscope device, an LED supporting block  555  is inserted from a front end portion of a substantially cylindrical adaptor housing (i.e., an outer cylinder portion)  553 , and a guide component  557  (i.e., a connecting component)  557  is inserted from a rear end portion of the adaptor housing  553 . 
     A flat side surface  553   a  that extends in the longitudinal direction of the lens adaptor  553  is formed on a portion of an outer surface of the front end portion of the adaptor housing  553 . A cut-out portion  559  that is cut out from the front end portion of the adaptor housing  553  is formed in the side surface  553   a . The rear end portion of the adaptor housing  553  is formed in a substantially circular cylinder shape. Furthermore, a step portion  553   b  that connects together the front end portion side surface  553   a  and the rear end portion outer circumferential surface is formed at an intermediate portion of the adaptor housing  553 . 
     An objective lens group  561  and a plurality of LED chips  15  are provided on the LED supporting block  555 . The objective lens group  561  is formed by a first lens group  561   a  that is placed on the guide component  557  side, a second lens group  561   b  that is placed at a position where it is exposed to the outside through a side surface of the LED supporting block, and a prism  561   c  that is placed between the first lens group  561   a  and the second lens group  561   b . The prism  561   c  alters an optical path of light irradiated from the outside into the second lens group  561   b  so that it is irradiated into the first lens group  561   a.    
     The second lens group  561   b  and the plurality of LED chips  15  are arranged in line on a flat side surface  555   a  of the LED supporting block  555 . Specifically, a non-conductive plate-shaped component  567  on which the plurality of LED chips  15  are mounted and the second lens group  561   b  are placed respectively within two recessed portions  563  and  565  that are cut out from the side surface  555   a . The portion above the non-conductive plate-shaped component  567  may be filled with a transparent resin or a transparent cover glass may be placed thereon so that the non-conductive plate-shaped component  567  can be protected by the resin or cover glass. 
     The above described LED supporting block  555  is fixed by a screw  569  to an inner surface in the intermediate portion of the adaptor housing  553 . In a state in which the LED supporting block is fixed to the adaptor housing  553 , the side surface  555   a  of the LED supporting block  555  is exposed to the outside through the cut-out portion  559 , and a single flat surface is formed by the side surface  555   a  of the LED supporting block  555  and the side surface  553   a  of the adaptor housing  553 . 
     A cut-out portion  571  is formed in a front end portion of the guide component  557  that is assembled with the connecting ring  28 . This cut-out portion  571  is formed such that the guide component  557  abuts against both the rear end portion of the LED supporting block  555  and the step portion  553   b  of the adaptor housing  553 . When the guide component  557  is assembled in the connecting ring  28 , it is fixed to an inner surface of a rear portion of the adaptor housing  553  by a screw (not shown). 
     Note that a pair of electrodes  571   a  and  571   b  that are electrically connected to the plurality of LED chips  15  is embedded in the non-conductive plate-shaped component  567  so as to be adjacent to each other. Moreover, wires  573   a  and  573   b  are connected respectively to the two electrodes  571   a  and  571   b , and each of these wires  573   a  and  573   b  are inserted through a guide hole  575  that penetrates from a bottom surface of the recessed portion  563  where the non-conductive plate-shaped component  567  is placed to a rear end portion of the LED supporting block  555 . The respective wires  573   a  and  573   b  are connected respectively to the pair of electrode substrates  475   a  and  475   b  that are provided at a rear end portion of the guide hole  575 , and to the adaptor electrodes  477   a  and  477   b.    
     Accordingly, current can be supplied to the plurality of LED chips  15  by joining the connecting ring  28  to the distal end portion of the connecting plug  9 , and pressing in the respective adaptor electrodes  477   a  and  477   b  using the pair of electrodes  479   a  and  479   b  that are provided adjacent to each other at a distal end portion of the connecting plug. 
     In the endoscope device of this embodiment, in the same way as in the endoscope device of the fifth embodiment, because all of the lens elements of the objective lens group  561  are provided on the LED supporting block  555 , it is possible to reduce the number of components due to it no longer being necessary to place a separate lens supporting block at a rear portion of the LED supporting block  555 , and there is also an improvement in the workability of the assembly task. 
     Moreover, because it is no longer necessary to place a separate lens supporting block on the inner side of the LED supporting block  555 , it is possible to reduce the size of the outer diameter of the LED supporting block  555  and achieve a reduction in the size of the lens adaptor  551  without reducing the outer diameter of the objective lens group  561  more than is necessary. 
     As in this eighth embodiment, when a structure is employed in which the LED supporting block  555  and the guide component  557  are inserted into the adaptor housing  553  from different directions, then, as in the ninth embodiment shown in  FIGS. 17 and 18 , a substantially circular cylinder-shaped adaptor housing (i.e., an outer cylinder portion)  581  may be formed integrally with a rear end portion of an LED supporting block  583 . In this case, it is possible to reduce the number of constituent components of the lens adaptor  585 . Accordingly, a reduction in production costs of the lens adaptor  585  can be achieved and the task of assembling the lens adaptor  585  can be performed easily. 
     Moreover, in the eighth embodiment, the LED supporting block  555  is inserted from the front end portion of the adaptor housing  553  (see  FIGS. 14 to 16 ), however, the present invention is not limited to this and, as in the tenth embodiment shown in  FIGS. 19 to 21 , it is also possible for an LED supporting block  601  to be inserted from a rear end portion of an adaptor housing (i.e., an outer cylinder portion)  603  that is formed in a substantially circular cylinder shape. 
     An aperture portion  605  that exposes the plurality of LED chips  15  that are located on a side surface  601   a  of the LED supporting block  601  and a second lens group  561   b  to the outside, and also an end surface wall portion (i.e., an abutting wall portion)  607  that protrudes inwards from an outer surface of the adaptor housing  603  are formed at a front end portion of the adaptor housing  603 . When the LED supporting block  601  is inserted from a rear end portion of the adaptor housing  603 , the end surface wall portion  607  performs the function of abutting against a front end portion of the LED supporting block  601  that is positioned at the front in the insertion direction. 
     In the case of this structure, because it is possible to assemble a lens adaptor  611  by inserting the LED supporting block  601  together with a guide portion (i.e., connecting portion)  609  from the rear end portion of the adaptor housing  603 , as is shown in the drawings, it is possible to form the guide portion  609 , which is assembled with the connecting ring  28 , integrally with the rear end portion of the LED supporting block  601 . 
     Accordingly, the number of constituent components of the lens adaptor  611  can be reduced, thereby allowing a reduction in the production costs of the lens adaptor  611  to be achieved and enabling the task of assembling the lens adaptor  611  to be performed easily. Moreover, because it is possible for heat generated from the LED chips  15  to be released to the flexible tube  1  via only two components, namely, the LED supporting block  601  and the connecting ring  28 , heat discharge from the LED chips  15  can be performed efficiently. Furthermore, because the components on which the LED chips  15  are mounted, such as the non-conductive plate-shaped component  16  and the LED supporting block  501 , are exposed to the outside, the effect is achieved that heat from the LED chips  15  can be efficiently discharged to the outside. 
     Note that, if the efficiency of the heat discharge from the LED chips  15  is not a consideration, then it is also possible, for example, to disconnect the guide component  609  from the LED supporting block  601  and form it using a different component. 
     Moreover, in the eighth and ninth embodiments, all of the lens elements of the objective lens group  561  are mounted on the LED supporting block (see  FIGS. 14 to 16 ), however, the present invention is not limited to this and, as in the eleventh embodiment shown in  FIG. 22 , it is also possible to mount a portion of the objective lens group  561  (i.e., the first lens group  561   a  that is located on the guide component  557  side) on a separate lens supporting block  631 , and to mount the remainder of the constituent lenses (i.e., the second lens group  561   b  and the prism  561   c ) making up the objective lens group  561  on a lens supporting block  633 . 
     An insertion hole that is cut out from a rear surface of the LED supporting block  633  and through which is inserted the lens supporting block  631  is formed in the lens supporting block  633 , and a female thread  635  is formed on an inner circumferential surface of this insertion hole. The lens supporting block  631  is formed in a substantially circular cylinder shape, and a male thread  637  that screws into the female thread  635  of the LED supporting block  633  is formed on an outer circumferential surface of the lens supporting block  631 . Namely, the LED supporting block  633  is able to be fitted onto and removed from the front surface of the lens supporting block  631  via the female screw  635  and the male screw  637 . 
     In the case of this structure, by rotating the lens supporting block  631  relative to the LED supporting block  633  and also moving the position thereof forwards or backwards, it is possible to adjust the focus of the objective lens group  561 . 
     It is also possible to remove the LED supporting block  633  from the front surface of the lens supporting block  631  and replace it, if necessary, with a an LED supporting block that is suitable for another application. At this time, the second lens group  561   b  of the lens supporting block  631  can be shared. 
     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 limited by the foregoing description and is only limited by the scope of the appended claims. 
     The endoscope device of the present invention can be favorably used for industrial and medical applications.