Abstract:
A substrate connection structure includes: a first substrate having stiffness with a first connector mounted on a front face; a second substrate having stiffness with a second connector detachably attached to the first connector mounted on a front face facing the front face of the first substrate; and a restricting member including a projection portion, the restricting member including a plate-like member and being detachably attachable to the first substrate by being moved along a planar surface of the first substrate, the projection portion projecting from the front face of the first substrate and regulating a position of the second substrate relative to the first substrate in a state in which the restricting member is attached to the first substrate, and limiting a direction in which the second substrate is detached when the second connector mounted on the second substrate is detached from the first connector on the first substrate.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of PCT/JP2013/078164 filed on Oct. 17, 2013 and claims benefit of Japanese Application No. 2012-261196 filed in Japan on Nov. 29, 2012, the entire contents of which are incorporated herein by this reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a substrate connection structure in which a second connector mounted on a second substrate is detachably attachable to a first connector mounted on a first substrate. 
     2. Description of the Related Art 
     Endoscopes are used in, e.g., medical fields and industrial fields. Examples of the endoscopes include what are called electronic endoscopes with an image pickup apparatus incorporated in a distal end portion of an insertion portion thereof. For the electronic endoscopes, there is a demand for image quality enhancement, and thus, e.g., an increase in number of pixels in image pickup devices is being pursued. 
     In the endoscopes, there is a long transmission passage connecting the image pickup apparatus incorporated in the distal end portion of the insertion portion and, for example, a video processor, which is an external apparatus. Therefore, a relay substrate that amplifies a drive signal for an image pickup device is provided inside the endoscope operation portion to enhance the image quality and reduce a diameter of a signal cable inserted inside the insertion portion. 
     Inside the endoscope operation portion, many incorporated endoscope components are inserted in addition to the signal cable. Examples of the incorporated endoscope components include, e.g., a light guide fiber bundle for supplying illuminating light, an air feeding tube included in an air feeding conduit, a water feeding tube included in a water feeding conduit, a dual-purpose tube that serves as a suction conduit and a treatment instrument conduit, and bending wires that make a bending portion perform a bending operation. 
     Thus, the relay substrate is configured to have a small size and is provided in the endoscope operation portion in consideration of assembly and repair workability. 
     For example, Japanese Patent Application Laid-Open Publication No. 2009-277534 indicates a fill-like connector structure that enables reduction in height and space of a connection portion, the connector structure preventing a female connector and a male connector from being separated even when the connector structure is subject to impact or vibration. 
     SUMMARY OF THE INVENTION 
     A substrate connection structure according to an aspect of the present invention includes: a first substrate with a first connector mounted on a front face, the first substrate having stiffness; a second substrate with a second connector mounted on a front face facing the front face of the first substrate, the second connector being detachably attached to the first connector, the second substrate having stiffness; and a restricting member including a projection portion, the restricting member including a plate-like member and being detachably attachable to the first substrate by being moved along a planar surface of the first substrate, the projection portion projecting from the front face of the first substrate and regulating a position where the second substrate is disposed relative to the first substrate in a state in which the restricting member is attached to the first substrate, and limiting a direction in which the second substrate is detached when the second connector mounted on the second substrate is detached from the first connector on the first substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an endoscope; 
         FIG. 2  is a diagram illustrating a relay unit provided inside an operation portion of the endoscope; 
         FIG. 3  is a diagram illustrating a relationship between the relay unit, and a first signal cable and a second signal cable; 
         FIG. 4  is a diagram illustrating a configuration of a housing case and, e.g., a first substrate, a second substrate, the first signal cable and the second signal cable arranged in an inner space of a case body; 
         FIG. 5  is a diagram illustrating a state of connection between the first substrate and the second substrate; 
         FIG. 6  is a diagram illustrating a configuration of the first substrate and a restricting member disposed in a cutout portion of the first substrate; 
         FIG. 7  includes diagrams each illustrating engagement portions of the restricting member; 
         FIG. 8A  is a diagram illustrating a front face of the first substrate with the restricting member disposed in the cutout portion; 
         FIG. 8B  is a diagram illustrating a back face of the first substrate with the restricting member disposed in the cutout portion; 
         FIG. 9  is a diagram illustrating a relationship between the first substrate with the restricting member disposed in the cutout portion, and the second substrate; and 
         FIG. 10  is a diagram illustrating a state in which the first substrate and the second substrate are connected. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the present invention will be described below with reference to the drawings. 
     As illustrated in  FIG. 1 , an endoscope  1  includes an insertion portion  2 , an operation portion  3  and a universal cable  4 . An endoscope connector (not illustrated) is provided at a proximal end portion of the universal cable  4 . The endoscope connector is detachably connected to, for example, a camera control unit, which is an external apparatus. 
     The insertion portion  2  is an elongated member having a long length, which is to be inserted to a site to be observed. The insertion portion  2  includes a distal end portion  6 , a bending portion  7  and a flexible tube portion  8 , which are continuously provided. The distal end portion  6  incorporates an image pickup apparatus including an illumination optical system that includes a light guide (not illustrated) and an image pickup device  9  including, e.g., a CCD or C-MOS. The bending portion  7  is configured so as to bend in, for example, four directions, upward, downward, rightward and leftward. The flexible tube portion  8  is a tubular member having a long length and flexibility. 
     The operation portion  3  includes a combination of a first sheathing body  11  and a second sheathing body  12 . In the first sheathing body  11 , for example, a treatment instrument insertion port  13  is provided. A proximal end portion of the insertion portion  2  is integrally joined and fixed to the distal end side of the first sheathing body  11  via a bend preventing member  10 . 
     At the second sheathing body  12 , e.g., a bending operation portion  14 , various kinds of switches  15 , an air/water feeding button  16  and a suction button  17  are provided. At the bending operation portion  14 , for example, bending operation knobs  14   a  and  14   b  for performing a bending operation of the bending portion  7  are provided. A surgeon turns, for example, the bending operation knob  14   a  in a predetermined direction, whereby non-illustrated bending wires are pulled or loosened to bend the bending portion  7  upward. 
     Note that examples of the various kinds of switches  15  include, e.g., a release switch, a freeze switch and an observation mode selection switch for switching between normal observation and fluorescent observation. 
     As illustrated in  FIG. 2 , a fixed plate  18 , which is an operation portion framework component, is integrally fixed at a predetermined position in the second sheathing body  12  included in the operation portion  3 . The fixed plate  18  includes, for example, a stainless steel. The fixed plate  18  is shaped so that various kinds of components provided in the operation portion  3  can be attached to the fixed plate  18  in an optimum manner. 
     Reference numeral  20  denotes a relay unit. The relay unit  20  includes a housing case  23  including a case body  21  and a cover body  22 . The housing case  23  is detachably attached to a predetermined position in the fixed plate  18  via attachment screws  32   a  and  32   b.    
     As illustrated in  FIG. 3 , a first signal cable  9   a  and a second signal cable  9   b  are connected to the relay unit  20 . 
     An end of the first signal cable  9   a  is connected to, for example, a substrate inside the endoscope connector. The other end of the first signal cable  9   a  is connected to a first drive signal relay substrate (reference numeral  24  in  FIG. 4  and abbreviated as “first substrate”), which will be described later, inside the relay unit  20 . 
     The second signal cable  9   b  extends from the image pickup device  9  provided in the insertion portion  2 . An end of the second signal cable  9   b  is connected to the image pickup device  9 . The other end of the second signal cable  9   b  is connected to a second drive signal relay substrate (reference numeral  25  in  FIG. 4  and abbreviated as “second substrate”), which will be described later, inside the relay unit  20 . 
     In a state in which the relay unit  20  is attached and fixed to the fixed plate  18 , the first signal cable  9   a  and the second signal cable  9   b  thrust into the housing case  23  from the proximal end face side of the relay unit  20 . 
     Here, e.g., the relay unit  20  and a substrate connection structure provided inside the unit will be described. 
     As illustrated in  FIG. 4 , the housing case  23  includes the case body  21  and the cover body  22  integrally fixed via a fixing screw  33 . The housing case  23  is a shielding case. The case body  21  is configured in a box shape using a shielding member. The cover body  22  is also configured in a box shape using a shielding member. The cover body  22  occludes an opening of the case body  21 . 
     As a result of removing the fixing screw  33  from the housing case  23 , the case body  21  and the cover body  22  are separated from each other in such a manner as illustrated in the figure. In an inner space of the case body  21 , e.g., the first substrate  24 , the second substrate  25 , the first signal cable  9   a  and the second signal cable  9   b  are arranged. 
     As illustrated in  FIG. 5 , a first connector  26  is mounted on a front face that is one surface of the first substrate  24 . A second connector  27  is mounted on a front face of the second substrate  25 . The first substrate  24  and the second substrate  25  are integrally joined and electrically connected by connecting the first connector  26  and the second connector  27 . 
     Reference numerals  28   a ,  28   b  and  28   c  illustrated in  FIGS. 4 and 5  denote projection portions, which are configured so as to stand from a back face that is another surface of the first substrate  24 . Reference numeral  28  indicated in  FIG. 5  denotes a restricting member. 
     The projection portions  28   a ,  28   b  and  28   c  form a regulating portion  28 S that regulates a position where the second substrate  25  is disposed on the front face of the first substrate  24 . In the present embodiment, the projection portions  28   a ,  28   b  and  28   c  are provided so as to surround predetermined three sides of the second substrate  25 . 
     More specifically, the first projection portion  28   a  is provided so as to face a long side of the second substrate  25 . The second projection portion  28   b  is provided so as to be opposed to the first projection portion  28   a  and face the other long side of the second substrate  25 . The third projection portion  28   c  is provided so as to face a short side of the second substrate  25  on which the second connector  27  is mounted. 
     Reference numeral  28   h  in  FIG. 6  denotes a short-side open portion. On the short-side open portion  28   h  in which no projection portions  28   a ,  28   b  and  28   c  are provided in the restricting member  28 , the second signal cable  9   b  extending from the other short side of the second substrate  25  is disposed. 
     Reference numeral  28   d  indicated in  FIGS. 5 and 6  denotes a second cable holding hook. The second cable holding hook  28   d  holds an upper face, in the figure, of the second signal cable  9   b . As a result of the second cable holding hook  28   d  holding the upper face of the second cable  9   b , the cable  9   b  is prevented from being swayed in the arrow Y 5  direction. 
     Consequently, the trouble of the second substrate  25  being detached from the first substrate  24  as a result of the cable  9   b  being swayed in the arrow Y 5  direction is prevented. 
     Reference numeral  28   e  denotes first cable holding hooks. The first cable holding hooks  28   e  hold, e.g., a lower face, in the figure, of the first signal cable  9   a . As a result of the first cable holding hooks  28   e  holding, e.g., the lower face of the first cable  9   a , the cable  9   a  disposed along the back face of the first substrate  24  is prevented from being displaced in a longitudinal direction of the first substrate  24 . 
     Note that electronic components are mounted on at least one of the first substrate  24  and the second substrate  25  to amplify a drive signal for the image pickup device  9  in order to overcome signal deterioration such as attenuation and/or dullness. 
     Reference numeral  29  denotes a cable retainer member. The cable retainer member  29  is a member for positioning and fixing an end portion of the second cable  9   b  at an end portion of the second substrate  25 . 
     As illustrated in  FIG. 6 , in the present embodiment, the first substrate  24  and the restricting member  28  are separate members. The restricting member  28  includes the projection portions  28   a ,  28   b  and  28   c  and the cable holding hooks  28   d  and  28   e . In other words, as a result of the restricting member  28  being attached to the first substrate  24 , the projection portions  28   a ,  28   b  and  28   c  are provided so as to stand from the front face of the substrate  24 . 
     The restricting member  28  includes a conductive member or a non-conductive member. If the restricting member  28  is intended to provide a shielding effect, the restricting member  28  includes a metal, such as a stainless steel. On the other hand, if the restricting member  28  is intended to prevent electrical connection with peripheral components, the restricting member  28  includes a resin such as polyacetal. 
     In the restricting member  28 , one relief opening (hereinafter abbreviated as “opening”)  28   m  and a plurality of engagement portions  28   g  are provided in addition to the projection portions  28   a ,  28   b  and  28   c , the cable holding hooks  28   d  and  28   e  and the short-side open portion  28   h.    
     On the other hand, in the first substrate  24 , a cutout portion  30  is formed. The cutout portion  30  is configured so that the restricting member  28  is disposed therein. 
     The engagement portions  28   g  of the restricting member  28  each include a contact surface. The contact surface of each engagement portion  28   g  is brought into contact with a front face or a back face of a cutout long side  31  included in the cutout portion  30  of the first substrate  24 . More specifically, in the present embodiment, a first engagement portion  28   g   1  and a third engagement portion  28   g   3  are brought into contact with and thereby disposed on, for example, the front face of the cutout long side  31 . On the other hand, a second engagement portion  28   g   2  is brought into contact with and thereby disposed on, for example, the back face of the cutout long side  31 . 
     Then, as illustrated in (A) in  FIG. 7 , a bulge portion  28   f  that projects on the contact surface side is provided in the second engagement portion  28   g   2 . The bulge portion  28   f  is formed at a position that is a predetermined distance from an introduction portion having a width that is larger than a thickness of the first substrate  24 . The bulge portion  28   f  is, for example, a hemispherical bulge portion or a linear bulge portion. The hemispherical bulge portion is formed from the side opposite to the contact face side of the second engagement portion  28   g   2  by means of, for example, a punch. The linear bulge portion is formed along a longitudinal direction of the second engagement portion  28   g   2  by means of press work. 
     Note that a distance in width from a top of the bulge portion  28   f  to the contact surface of the first engagement portion  28   g   1  is smaller than the thickness of the first substrate  24 . A distance in width from the top of the bulge portion  28   f  to the contact surface of the third engagement portion  28   g   3  is smaller than the thickness of the first substrate  24 . 
     With such configuration, the restricting member  28  is disposed so as to be pinched to the cutout long side  31  of the first substrate  24  via the engagement portions  28   g   1 ,  28   g   2  and  28   g   3  with a predetermined elastic force. 
     Note that although it has been described above that the bulge portion  28   f  is provided in the second engagement portion  28   g   2 , the bulge portion  28   f  may be provided in each of the engagement portions  28   g   1 ,  28   g   2  and  28   g   3 . 
     Also, as illustrated in (B) in  FIG. 7 , a restricting member  28 A including opposed pinching portions  28   k  may be configured. The opposed pinching portions  28   k  form a retainer portion  28   i  having a width that is smaller than the thickness of the first substrate  24 . The retainer portion  28   i  is formed at a position that is a predetermined distance from an introduction portion having a width that is larger than the thickness of the first substrate  24 . 
     Furthermore, the restricting member  28  may be integrally fixed to the first substrate  24  by means of, e.g., solder, bonding, screws or swaging. 
     The opening  28   m  of the restricting member  28  is a through hole that brings the one surface side and the other surface side of the restricting member  28  into communication with each other. In the present embodiment, the opening  28   m  of the restricting member  28  has a rectangular shape. The opening  28   m  includes long sides and short sides as with the first connector  26  mounted on the first substrate  24 , the first connector  26  including long sides and short sides. 
     In the present embodiment, dimensions of the long sides and the short sides of the opening  28   m  are set to predetermined dimensions, which are larger than those of the first connector  26 . 
     Here, a procedure for assembling a relay unit  20  will be described. 
     A worker prepares, e.g., a first substrate  24 , a second substrate  25 , a restricting member  28 , a case body  21 , a cover body  22  and a fixing screw  33 . Signal wires in a first cable  9   a  are connected to connection portions (see reference numeral  24   t  in  FIG. 8B ) of the first substrate  24 . Signal wires in a second cable  9   b  are connected to connection portions (not illustrated) of the second substrate  25 . 
     First, the worker disposes the restricting member  28  in a cutout portion  30  of the first substrate  24 . Here, as indicated by arrow Y 6   a  in  FIG. 6 , the worker disposes a first connector  26  in the opening  28   m  and places the restricting member  28  on a front face of the first substrate  24 . Here, engagement portions  28   g   1 ,  28   g   2  and  28   g   3  are disposed in the cutout portion  30  without being in contact with a cutout long side  31 . 
     Next, the worker disposes the engagement portions  28   g   1 ,  28   g   2  and  28   g   3  disposed in the cutout portion  30 , on the cutout long side  31  in such a manner that the engagement portions  28   g   1 ,  28   g   2  and  28   g   3  pinch the cutout long side  31 . Thus, as indicated by arrow Y 6   b  in  FIG. 6 , the worker moves the restricting member  28  along a plane of the first substrate  24  to dispose the engagement portions  28   g   1 ,  28   g   2  and  28   g   3  on the first substrate  24 . 
     Then, as illustrated in  FIGS. 8A and 8B , the first engagement portion  28   g   1  and the third engagement portion  28   g   3  are brought into contact with and thereby disposed on a front face of the cutout long side  31  and a bulge portion  28   f  of the second engagement portion  28   g   2  is brought into contact with and thereby disposed on a back face of the cutout long side  31 , whereby the restricting member  28  is disposed so as to be pinched to the cutout long side  31  of the first substrate  24 . As a result, the restricting member  28  is detachably attached to the first substrate  24  without using an adhesive or screws. 
     Next, the worker connects a second connector  27  on the second substrate  25  to the first connector  26  on the first substrate  24 . Here, as illustrated in  FIG. 9 , the worker views and checks positions of a regulating portion  28 S including three projection portions  28   a ,  28   b  and  28   c , a short-side open portion  28   h  and the first connector  26  and determines a direction of the second substrate  25  according to the positions. 
     Subsequently, the worker disposes the second substrate  25  in the regulating portion  28 S. The worker connects the second connector  27  to the first connector  26  and disposes the second signal cable  9   b  extending from the short-side open portion  28   h  in the second cable holding hook  28   d.    
     As a result, as illustrated in  FIG. 10 , connection between the first substrate  24  and the second substrate  25  is completed. 
     In this connection state, the restricting member  28  disposed on the first substrate  24  so as to be pinched to the substrate  24  is prevented from coming off from the first substrate  24  by the second substrate  25 . 
     Next, the worker disposes the first substrate  24  with the restricting member  28  disposed thereon and the second substrate  25  connected thereto in an inner space of the case body  21 . 
     As a result, as illustrated in  FIG. 4  above, e.g., the first substrate  24 , the second substrate  25 , the first signal cable  9   a  and the second signal cable  9   b  are arranged in the inner space of the case body  21 . 
     Next, the worker puts the cover body  22  on the case body  21  to make an opening of the body  21  be occluded by the cover body  22 . Then, the cover body  22  and the case body  21  are integrally fixed to each other via a fixing screw  33 . 
     As a result, the relay unit  20  that houses the first substrate  24  and the second substrate  25  in the housing case  23  is configured. 
     The configuration in which the first substrate  24  and the second substrate  25  are housed in the housing case  23  reliably maintains the connection between the first substrate  24  and the second substrate  25  in the case and prevents the restricting member  28  disposed so as to be pinched from coming off. 
     Here, detachment of the second substrate  25  from the first substrate  24  will be described with reference to  FIG. 10 . 
     When a worker detaches the second substrate  25  from the first substrate  24 , the worker views and checks the positions of the regulating portion  28 S including three projection portions  28   a ,  28   b  and  28   c , and the second cable holding hook  28   d  provided at the first substrate  24  to confirm a direction in which the second substrate  25  is detached. 
     After the confirmation, the worker takes off the second signal cable  9   b  disposed in the second cable holding hook  28   d . Subsequently, the worker gradually moves the second signal cable  9   b  in the arrow Y 5  direction in  FIG. 5  while holding a cable retainer member  29  and an end portion of the second signal cable  9   b.    
     Then, the second substrate  25  is gradually inclined, whereby the second connector  27  and the first connector  26  are gradually disconnected. Then, the second substrate  25  is inclined to a predetermined position, whereby the second connector  27  is detached from the first connector  26 , and the second substrate  25  and the first substrate  24  are separated from each other. 
     As described above, the cutout portion  30  is configured in the vicinity of the first connector  26  mounted on the first substrate  24 , and the restricting member  28  including the regulating portion  28 S including the projection portions  28   a ,  28   b  and  28   c , the short-side open portion  28   h  and the second cable holding hook  28   d  is provided in the cutout portion  30 . As a result, a direction in which the second substrate  25  can be moved when the second substrate  25  is detached from the first substrate  24  is regulated by the projection portions  28   a ,  28   b  and  28   c.    
     Accordingly, the worker can easily confirm the direction in which the second substrate  25  is detached by viewing and checking the positions of the regulating portion  28 S including the three projection portions  28   a ,  28   b  and  28   c  and the second cable holding hook  28   d , which are provided in the first substrate  24 . As a result, the trouble of the second substrate  25  being detached in a wrong direction when the worker performs substrate detachment work to detach the second substrate  25  is prevented. 
     Also, when the worker connects the second substrate  25  to the first substrate  24 , the worker can dispose the second substrate  25  to be attached to the first substrate  24 , in a correct direction relative to the first substrate  24  by viewing and checking the positions of the regulating portion  28 S including the three projection portions  28   a ,  28   b  and  28   c , the short-side open portion  28   h  and the first connector  26 , which are provided on the first substrate  24 . 
     Accordingly, subsequently, the worker connects the second connector  27  to the first connector  26 , and disposes the second signal cable  9   b  extending from the short-side open portion  28   h  in the second cable holding hook  28   d , enabling easy and reliable connection between the first substrate  24  and the second substrate  25 . 
     Also, as a result of the engagement portions  28   g  being provided at the restricting member  28 , the worker can easily dispose the restricting member  28  on the first substrate  24  without preparing, e.g., solder, an adhesive or screws and without performing, e.g., soldering work, bonding work, thread connection work or swaging work. 
     Note that if the restricting member  28  includes a conductive member, a ground pattern  28   p  is provided on a part of a back face of the first substrate  24 , the part corresponding to the bulge portion  28   f  of the second engagement portion  28   g   2 , which is illustrated in  FIG. 8B , to electrically connect the ground pattern  28   p  and the restricting member  28 . In addition, shielding wires in the first signal cable  9   a  are collected in a bundle and connected to the first cable holding hooks  28   e.    
     This configuration enables an increase in shielding effect. 
     Note that a ground pattern  28   p  electrically connected to the first engagement portion  28   g   1  and a ground pattern  28   p  electrically connected to the third engagement portion  28   g   3  may be provided on the first substrate  24 , respectively. 
     Note that the present invention is not limited only to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.