Abstract:
According to the invention, a disadvantage in the production cost for producing a wiring board, which may occur when an electrical connector element and a photoelectric conversion connector element are to be surface mounted, is eliminated. A connector has a first unit serving as the electrical connector element, and a second unit serving as the photoelectric conversion connector element which is attachable to and detachable from a rear end portion of the first unit. A first soldering terminal of the surface mount type disposed on the first unit is placed on a side portion of the body, and a second soldering terminal of the surface mount type disposed on the second unit is placed on a rear portion of a holder.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the invention  
           [0002]    The present invention relates to an electrical/photoelectric conversion dual connector.  
           [0003]    2. Description of the Prior Art  
           [0004]    As one of known examples, Japanese Utility Model Publication No. 2-31735 discloses a pin jack with an optical device. In the pin jack with an optical device, a pin type electrical plug and a pin type optical plug can be selectively inserted into and extracted from a through hole of the body which houses contacts, and a holding portion which has a photoelectric conversion device can be attached to and detached from a rear end portion of the body. Soldering terminals which downward protrude are formed on the body and the holding portion. When the pin jack is to be mounted to a wiring board, the soldering terminals are passed respectively through terminal holes of the wiring board and then soldered.  
           [0005]    In a portable apparatus such as a portable telephone or a portable audio reproduction apparatus which has become largely widespread in recent years, an electrical/photoelectric conversion dual connector which can be used for both an electrical connection with a pin type electrical plug and an optical connection with a pin type optical plug is sometimes incorporated. In such a case, it is often advantageous that the connector is mounted in the state where soldering terminals do not protrude from the rear side of the wiring board, i.e., the surface mounted state in view of miniaturization and thinning of the portable apparatus. In some of electrical/photoelectric conversion dual connectors of this kind, as seen in the conventional art example described above, a photoelectric conversion connector element can be attached to and detached from an electrical connector element. In accordance with the function of the portable apparatus, such connectors are classified into those in which it is requested to incorporate only an electrical connector element, and those in which it is requested to incorporate both an electrical connector element and a photoelectric conversion connector element.  
           [0006]    Under these circumstances, a configuration in which a wiring board for surface mounting only an electrical connector element, and that for surface mounting both an electrical connector element and a photoelectric conversion connector element must be individually produced is disadvantageous from the viewpoint of cost.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention has been conducted under such circumstances. It is an object of the invention to provide an electrical/photoelectric conversion dual connector in which the arrangement of surface mount type soldering terminals that are disposed on an electrical connector element and a photoelectric conversion connector element is improved so as to enable one wiring board to be used as that for surface mounting only an electrical connector element and also as that for surface mounting both an electrical connector element and a photoelectric conversion connector element, whereby the cost can be lowered.  
           [0008]    It is another object of the invention to provide an electrical/photoelectric conversion dual connector in which an electrical connector element with which a photoelectric conversion connector element is to be combined is a multipolar one.  
           [0009]    It is a further object of the invention to provide an electrical/photoelectric conversion dual connector in which a photoelectric conversion connector element can be correctly positioned with respect to an electrical connector element, so that both the elements can be surface mounted on a wiring board easily and adequately.  
           [0010]    It is a still further object of the invention to provide an electrical/photoelectric conversion dual connector having a structure which can compensate strength reduction due to miniaturization to satisfy practical strength.  
           [0011]    The electrical/photoelectric conversion dual connector of the invention comprises: a first unit serving as an electrical connector element having an insertion hole in a body into which a contact is incorporated, a pin type optical plug and a pin-type electrical plug being selectively insertable into and extractable from the insertion hole, the pin type optical plug holding an end portion of an optical fiber, the pin-type electrical plug having a terminal that is to be connected to the contact; and a second unit serving as a photoelectric conversion connector element comprising a holder which is attachable to and detachable from a rear end portion of the body of the first unit, and which holds a photoelectric conversion device that, in an attached state, is placed coaxially with an optical axis of the optical fiber held by the pin type optical plug inserted into the insertion hole.  
           [0012]    Both the first and second units are formed as surface mounting type units, a first soldering terminal of a surface mount type disposed on the first unit is placed on a side portion of the body, and a second soldering terminal of the surface mount type disposed on the second unit is placed on a rear portion of the holder.  
           [0013]    When the first soldering terminal of the first unit is placed on a side portion of the body and the second soldering terminal disposed on the second unit is placed on a rear portion of the holder as described above, a soldering land forming region on a wiring board can be divided into a region corresponding to the first soldering terminal, and that corresponding to the second soldering terminal. Therefore, a wiring board having a certain pattern of soldering lands can be used as a wiring board for surface mounting only an electrical connector element, and also as that for surface mounting both an electrical connector element and a photoelectric conversion connector element. This is useful for reducing the kinds of wiring boards to enable the cost to be easily reduced.  
           [0014]    As a preferable mode, the electrical/photoelectric conversion dual connector of the invention may employ a configuration in which the first unit is a multipolar unit comprising a plurality of contacts and a plurality of the first soldering terminals which are continuous respectively to the contacts, part of the first soldering terminals is placed on one lateral side of the body, and other part of the first soldering terminals is placed on another lateral side of the body. According to the configuration, it is possible to provide an electrical/photoelectric conversion dual connector in which the electrical connector element with which the photoelectric conversion connector element is to be combined is a multipolar element.  
           [0015]    As another preferable mode, in the electrical/photoelectric conversion dual connector of the invention, preferably, the holder comprises a pair of right and left arms which forward protrude to be longitudinally fittable into and extractable from the rear end portion of the body, and which, in a fitted state, overlap with right and left outer side faces of the rear end portion of the body, respectively, front end portions of the arms respectively comprise engaging claws which are to be engaged with engagement steps formed on right and left outer side faces of the body, to cooperate with a front end face of the holder to clampingly hold the rear end portion of the body, and a positioning protrusion is disposed integrally on the holder, the positioning protrusion being to be inserted into a recess formed in the rear end portion of the body to overlap with upper and lower wall faces of the recess, thereby restricting a level position of the second unit with respect to the first unit to make a level of a lower face of the second soldering terminal coincident with a level of a lower face of the first soldering terminal.  
           [0016]    According to the configuration, the second unit is correctly positioned with respect to the first unit in the longitudinal, lateral, and vertical directions. Namely, the positioning of the second unit with respect to the first unit in the longitudinal direction is correctly performed by the clamping of the rear end portion of the body due to the cooperation of the front end face of the holder and the engaging claws engaged with the engagement steps. The positioning of the units in the lateral direction is correctly performed by the overlapping of the pair of arms forward protruding from the holder with the right and left outer side faces of the rear end portion of the body. The positioning of the units in the vertical direction is correctly performed by the overlapping of the positioning protrusion of the holder with the upper and lower wall faces of the recess of the body. Since the second unit is vertically positioned with respect to the first unit, the level of the lower face of the second soldering terminal is coincident with that of the lower face of the first soldering terminal, so that adequate soldering in the surface mounting process can be easily performed. Since the second unit is correctly positioned with respect to the first unit in the longitudinal, lateral, and vertical directions as described above, all of the first and second soldering terminals can be correctly placed on all of the soldering lands of the wiring board, respectively.  
           [0017]    As a further preferable mode, in the invention, two or right and left portions of a wall face of the insertion hole in the rear end portion of the body are removed away, the recess is disposed in the rear end portion of the body and outside one of the removed portions with facing the one removed portion, another recess is disposed in the rear end portion of the body and outside another one of the removed portions with facing the other removed portion, the holder comprises an auxiliary protrusion which is to be inserted into the other recess to laterally oppose the positioning protrusion inserted into the recess, and each of the positioning and auxiliary protrusions comprises an arcuately curved face which forms a part of the wall face of the insertion hole in corresponding one of the removed portions. According to the configuration, the positioning and auxiliary protrusions of the second unit are useful for positioning a tip end portion of the pin type optical plug inserted into the insertion hole, with respect to a photoelectric conversion element of the second unit.  
           [0018]    As a further preferable mode, in the invention, it is possible to employ a configuration in which the first unit comprises an odd number of first soldering terminals, the soldering terminals are classified into an even number of first soldering terminals and one first soldering terminal, the one first soldering terminal comprises a plate-like rising piece, and placed on a projection piece which rearward protrudes from one lateral side of the rear end portion of the body, the rising piece overlaps with an inner side of the projection piece, the even number of first soldering terminals are distributed by a same number to lateral sides of the body, and, when the second unit is attached to the first unit, an overlapping portion of the projection piece and the rising piece is fitted into a recess formed in an inner side of one of the arms of the holder.  
           [0019]    According to the configuration, the second unit is laterally positioned with respect to the first unit by the fitting between the recess of the holder and the projection piece of the body which is fitted into the recess. Therefore, the positioning function exerted by the fitting assists the above-mentioned positioning function exerted by the overlapping of the pair of right and left arms with the right and left outer side faces of the body. Even in the case where the pair of right and left arms cannot be provided with high strength because the holder has a very small size, the positioning function by the fitting synergistically cooperates with that by the pair of right and left arms to surely laterally position the second unit with respect to the first unit. Moreover, the projection piece is reinforced by the rising piece which overlaps with the projection piece, and the overlapping portion of the projection piece and the rising piece is backed up by the arm. Even when a force of relatively moving the first and second units in a lateral direction is accidentally applied, therefore, a situation where the projection piece is easily broken can be prevented from occurring. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a front view of a first unit in an embodiment of the invention;  
         [0021]    [0021]FIG. 2 is a view looking in the direction of the arrow II in FIG. 1;  
         [0022]    [0022]FIG. 3 is a view looking in the direction of the arrow III in FIG. 1;  
         [0023]    [0023]FIG. 4 is a view looking in the direction of the arrow IV in FIG. 1;  
         [0024]    [0024]FIG. 5 is a view looking in the direction of the arrow V in FIG. 4;  
         [0025]    [0025]FIG. 6 is a front view of a holder of a second unit in the embodiment of the invention;  
         [0026]    [0026]FIG. 7 is a view looking in the direction of the arrow VII in FIG. 6;  
         [0027]    [0027]FIG. 8 is a view looking in the direction of the arrow VIII in FIG. 6;  
         [0028]    [0028]FIG. 9 is a view looking in the direction of the arrow IX in FIG. 6;  
         [0029]    [0029]FIG. 10 is a section view taken along the line X-X in FIG. 6;  
         [0030]    [0030]FIG. 11 is a section view taken along the line XI-XI in FIG. 7;  
         [0031]    [0031]FIG. 12 is a plan view of an electrical/photoelectric conversion dual connector of the embodiment of the invention;  
         [0032]    [0032]FIG. 13 is a bottom view of the electrical/photoelectric conversion dual connector;  
         [0033]    [0033]FIG. 14 is a side view of the electrical/photoelectric conversion dual connector;  
         [0034]    [0034]FIG. 15 is a circuit diagram of an electric circuit in the first unit; and  
         [0035]    [0035]FIG. 16 is a partial plan view of a wiring board showing an arrangement pattern of soldering lands. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0036]    FIGS.  1  to  5  show a first unit  10  serving as an electrical connector element which is used in an electrical/photoelectric conversion dual connector of an embodiment of the invention.  
         [0037]    The first unit  10  is a multipolar connector element in which a plurality of contacts are incorporated into a body  20  configured by an integrally molded member of a synthetic resin having: a body main portion  21  that is formed into a box-like shape having a rectangular shape in a plan view; and a cylindrical boss portion  22  that forward protrudes from the body main portion  21 . A circular insertion hole  23  is straightly formed so as to elongate over the boss portion  22  and the body main portion  21 . A pin type electrical plug and a pin type optical plug which are not shown can be selectively inserted into and extracted from the insertion hole  23 .  
         [0038]    [0038]FIG. 15 is a circuit diagram of an electric circuit in the first unit  10 . As shown in the figure, the first unit  10  has seven contacts C 1  to C 7  constituting seven poles. First soldering terminals T 1  to T 7  are continuous respectively to the contacts C 1  to C 7 . As can be inferred from FIGS.  1  to  5 , the three front contacts C 1  to C 3  are disposed by using the boss portion  22 , and the four rear contacts C 4  to C 7  are disposed on the body main portion  21 . Among the seven (odd number of) first soldering terminals T 1  to T 7 , the six (even number of) first soldering terminals T 1  to T 6  which are continuous respectively to the contacts C 1  to C 6  are distributed by the same number or three to the one and other sides in the lateral direction W (FIG. 2) of the body main portion  21 . As shown in FIG. 5, the remaining one first soldering terminal T 7  is placed on a projection piece  24  which rearward protrudes from one side in the lateral direction W of a rear end portion of the body main portion  21 , and a plate-like rising piece  47  which is disposed on the first soldering terminal T 7  overlaps with the inner side of the projection piece  24 .  
         [0039]    The soldering terminals T 1  to T 6  which are disposed by three on each of the right and left sides of the body main portion  21  protrude in a plate piece-like manner toward the outer side of the body main portion  21  so that the lower faces of the terminals are substantially flush with the flat lower face of the body main portion  21 . By contrast, the remaining one soldering terminal T 7  protrudes toward the outer side from the lower end of the projection piece  24 , and the level of the lower face of the terminal is coincident with the levels of the lower faces of the other six soldering terminals T 1  to T 6 . Since the lower faces of the seven soldering terminals T 1  to T 7  are in the same level, the soldering terminals T 1  to T 7  can be used as terminals of a surface mounting type device. A positioning protrusion  26  is disposed in each of two or front and rear positions of the lower face  25  of the body main portion  21 . When the protrusions  26  are fitted into two positioning holes  110  of a wiring board  100  which will be described later, the mounting position of the connector on the wiring board  100  can be determined (see FIG. 16).  
         [0040]    As seen from FIG. 5, two portions of the insertion hole  23  in the rear end portion of the body main portion  21  are removed away, and right and left individual recesses  31  and  32  are disposed outside the right and left removed portions  28  and  29 , respectively. The contact C 7  which is continuous to the rising piece  47  protrudes so as to cross the one recess  31 . Upper and lower wall faces  31   a ,  31   b ,  32   a , and  32   b  of the right and left recesses  31  and  32  are formed as flat faces.  
         [0041]    [0041]FIG. 16 is a partial plan view of the wiring board  100  to which the first unit  10  is to be surface mounted. As shown in the figure, the positioning holes  110  into which the two positioning protrusions  26  of the first unit  10  are fitted are opened in the wiring board  100 . A total of seven soldering lands  121  to  127  are formed so as to be distributed on both the sides of the positioning holes  110 . The soldering lands  121  to  127  are formed in positions where, when the positioning protrusions  26  of the first unit  10  are fitted into the positioning holes  110 , the seven soldering terminals T 1  to T 7  of the first unit  10  overlap with the lands, respectively. Therefore, the first unit  10  can be surface mounted to the wiring board  100  in the following manner. The positioning protrusions  26  are fitted into the positioning holes  110 , so that the flat lower face  25  of the body main portion  21  overlaps with the wiring board  100  and the seven soldering terminals T 1  to T 7  overlap with the seven soldering lands  121  to  127 , respectively. Thereafter, the overlapping portions are soldered.  
         [0042]    When a pin type electrical plug is inserted into the insertion hole  23  of the first unit  10  which is surface mounted to the wiring board  100  as described above, the contacts C 1  to C 7  of the body  20  are elastically in contact with plural terminals of the pin type electrical plug to attain electrical conduction, respectively.  
         [0043]    FIGS.  6  to  11  show a holder  60  of a second unit  50  serving as a photoelectric conversion connector element which is used in the electrical/photoelectric conversion dual connector of the embodiment of the invention. FIG. 6 is a front view, FIG. 7 is a view looking in the direction of the arrow VII in FIG. 6, FIG. 8 is a view looking in the direction of the arrow VIII in FIG. 6, FIG. 9 is a view looking in the direction of the arrow IX in FIG. 6, FIG. 10 is a section view taken along the line X-X in FIG. 6, and FIG. 11 is a section view taken along the line XI-XI in FIG. 7. FIG. 12 is a plan view of the electrical/photoelectric conversion dual connector A in which the second unit  50  is attached to the first unit  10 , FIG. 13 is a bottom view of the electrical/photoelectric conversion dual connector A, and FIG. 14 is a side view of the electrical/photoelectric conversion dual connector A.  
         [0044]    As shown in FIG. 7 or  11 , the holder  60  is formed into a hollow box-like shape having an opened lower face. A photoelectric conversion element  61  is housed and held in the holder as shown in FIG. 13, thereby forming the second unit  50 . As shown in FIG. 6, 10, or  11 , a circular opening  68  is formed in a front wall  67  of the holder  60 . As shown in FIG. 12, the photoelectric conversion element  61  which is housed and held in the holder  60  faces the opening  68 .  
         [0045]    A pair of right and left arms  62  and  63  which forward protrude are disposed on the holder  60 . In the state where the second unit  50  is attached to the first unit  10 , as shown in FIG. 12 or  13 , the arms  62  and  63  are fitted onto the outer side of the rear end portion of the body main portion  21  of the first unit  10  to overlap with the right and left outer side faces of the rear end portion of the body main portion  21 . As shown in FIG. 12 or  14 , engaging claws  64  and  65  which are disposed on front end portions of the arms  62  and  63  are engaged with channel-like engagement steps  34  and  35  formed on right and left outer side faces of the rear end portion of the body main portion  21 , respectively, so that a front end face  66  (the front wall  67 ) of the holder  60  butts against a rear end face  36  of the body main portion  21 . When the second unit  50  is attached to the first unit  10 , therefore, the rear end portion of the body main portion  21  is clampingly held by the cooperation of the front end face  66  of the holder  60  and the engaging claws  64  and  65 .  
         [0046]    As shown in FIG. 6 or  10 , a positioning protrusion  71  protrudes from one side of the front wall  67  of the holder  60  with respect to the opening  68 , and an auxiliary protrusion  72  protrudes from the other side. A recess  73  is formed in a front end portion of the positioning protrusion  71 . The inner face of the positioning protrusion is formed as an arcuately curved face  74  which is forward flared and continuous to the peripheral face of the opening  68 . Also the inner face of the auxiliary protrusion  72  is formed as an arcuately curved face  75  which is forward flared and continuous to the peripheral face of the opening  68 . In the state where the second unit  50  is attached to the first unit  10 , as shown by the phantom lines in FIG. 5 showing the first unit  10 , the positioning protrusion  71  is inserted into the recess  31  of the body main portion  21  to overlap with the upper and lower wall faces  31   a  and  31   b  of the recess  31 , thereby restricting the level position of the second unit  50  with respect to the first unit  10 , and the curved face  74  of the positioning protrusion  71  faces the one removed portion  28  of the insertion hole  23  to form a part of the wall face of the insertion hole  23 . The contact C 7  is to be fitted into the recess  73  of the positioning protrusion  71 . By contrast, the auxiliary protrusion  72  is inserted into the other recess  32 , so that the protrusion laterally opposes the positioning protrusion  71  across the insertion hole  23 , and the curved face  75  of the auxiliary protrusion  72  faces the other removed portion  29  of the insertion hole  23  to form a part of the wall face of the insertion hole  23 . An overlapping portion  48  (see FIG. 5) of the projection piece  24  of the first unit  10  and the rising piece  47  is fitted into a recess  79  formed in the inner side of the one arm  63  of the holder  60  as shown in FIG. 12 or  13 .  
         [0047]    As shown in FIGS.  12  to  14 , the photoelectric conversion element  61  comprises three second soldering terminals T 8 , T 9 , and T 10 . The soldering terminals T 8  to T 10  are placed on a rear portion of the holder  60  with rearward protruding from the lower end edge of the holder  60 . Since the positioning protrusion  71  overlaps with the upper and lower wall faces  31   a  and  31   b  of the recess  31  of the body main portion  21  to restrict the level position of the second unit  50  with respect to the first unit  10 , the levels of the lower faces of the soldering terminals T 8  to T 10  are coincident with those of the lower faces of the first soldering terminals T 1  to T 7 . In this way, the lower faces of the seven soldering terminals T 1  to T 7  of the first unit  10  and the three soldering terminals TB to T 10  of the second unit  50  are in the same level, all the soldering terminals T 1  to T 10  can be used as terminals of a surface mounting type device in the state where the second unit  50  is attached to the first unit  10 .  
         [0048]    As shown in FIG. 16, soldering lands  128  to  130  respectively corresponding to the three soldering terminals T 8  to T 10  of the second unit  50  are formed on the wiring board  100  on which the soldering lands  121  to  127  corresponding to the seven soldering terminals Ti to T 7  of the first unit  10  are formed.  
         [0049]    Next, the operation will be described.  
         [0050]    In the case where the electrical/photoelectric conversion dual connector is requested to exert only the function of an electrical connector and not to exert that of a photoelectric conversion connector, the second unit  50  is omitted, and only the first unit  10  is surface mounted to the wiring board  100  as described above. As a result, when a pin type electrical plug is inserted into the insertion hole  23  of the first unit  10 , the contacts C 1  to C 7  of the body  20  are elastically in contact with plural terminals of the pin type electrical plug to attain electrical conduction and exert only the function of an electrical connector, respectively.  
         [0051]    By contrast, in the case where the connector is requested to exert both the functions of an electrical connector and a photoelectric conversion connector, the second unit  50  is attached to the first unit  10 , and both the units  10  and  50  are surface mounted to the wiring board  100 . The second unit  50  can be attached to the first unit  10  in a procedure in which the second unit  50  is attached to the first unit  10  before the surface mounting, and the units  10  and  50  are then surface mounted, or in another procedure in which the first unit  10  is surface mounted to the wiring board  100 , the second unit  50  is then attached to the first unit  10 , and a process of surface mounting the second unit  50  is thereafter performed.  
         [0052]    The second unit  50  is attached to the first unit  10  in the following manner. The pair of right and left arms  62  and  63  of the second unit  50  are fitted from the rear side of the first unit  10  to the outer side of the rear end portion of the body main portion  21  of the first unit, and the engaging claws  64  and  65  of the arms  62  and  63  are engaged with the engagement steps  34  and  35  of the body main portion  21 , so that the rear end portion of the body main portion  21  is clampingly held by the cooperation of the front end face  66  of the holder  60  and the engaging claws  64  and  65 . As a result, the positioning protrusion  71  of the second unit  50  is fitted into the one recess  31  of the body main portion  21  to overlap with the upper and lower wall faces  31   a  and  31   b  of the recess, and hence the level position of the second unit  50  with respect to the first unit  10  is restricted to make the levels of the lower faces of the second soldering terminals T 8  to T 10  coincident with those of the lower faces of the first soldering terminals T 1  to T 7 . Irrespective of which one of the procedures is employed, therefore, the first soldering terminals T 1  to T 7  and the second soldering terminals T 8  to T 10  can be soldered easily and adequately to the soldering lands  121  to  127  and  128  to  130  of the wiring board  100 , to allow the first unit  10  and the second unit  50  to be easily surface mounted.  
         [0053]    In the case where the first unit  10  and the second unit  50  are surface mounted to the wiring board  100  in this way, when a pin type electrical plug is inserted into the insertion hole  23  of the first unit  10 , the contacts C 1  to C 7  of the body  20  are elastically in contact with plural terminals of the pin type electrical plug to attain electrical conduction, whereby the function of an electrical connector is exerted. When a pin type optical plug (not shown) is inserted into the insertion hole  23  of the first unit  10 , the optical axis of an optical fiber held in the pin type optical plug is placed coaxially with the photoelectric conversion element  61  of the second unit  50 , and hence the pin type optical plug is optically connected to the photoelectric conversion element  61  of the second unit  50 , whereby the function of a photoelectric conversion connector is exerted.  
         [0054]    In this case, the positioning of the second unit  50  with respect to the first unit  10  in the longitudinal direction is correctly performed by the clamping of the rear end portion of the body main portion  21  due to the cooperation of the front end face  66  of the holder  60  and the engaging claws  64  and  65  engaged with the engagement steps  34  and  35 . The positioning of the units in the lateral direction is correctly performed by the overlapping of the pair of right and left arms  62  and  63  of the holder  60  with the right and left outer side faces of the rear end portion of the body main portion  21 . The positioning of the units in the vertical direction is correctly performed by the overlapping of the positioning protrusion  71  of the holder  60  with the upper and lower wall faces  31   a  and  31   b  of the one recess  31  of the body main portion  21 . Therefore, the optical axis of the optical fiber held in the pin type optical plug which is inserted into the insertion hole  23  of the first unit  10  is correctly placed coaxially with the photoelectric conversion element  61  of the second unit  50 . This is useful for preventing the function of a photoelectric conversion connector from being lost. Since the curved face  74  of the positioning protrusion  71  and the curved face  75  of the auxiliary protrusion  72  form a part of the wall face of the insertion hole  23  in the two right and left removed portions of the insertion hole  23 , the pin type optical plug is allowed to be easily held to an adequate position, by the positioning function exerted by the curved faces  74  and  75 . This is useful also for preventing the function of a photoelectric conversion connector from being lost.  
         [0055]    As shown in FIG. 12 or  13 , the overlapping portion  48  of the projection piece  24  of the first unit  10  and the rising piece  47  is fitted into the recess  79  formed in the inner side of the one arm  63  of the holder  60 , thereby producing a state where the overlapping portion  48  is backed up by the arm  63 . Even when a pin type electrical plug or a pin type optical plug is elastically in contact with the contact C 7  which is continuous to the rising piece  47  of the overlapping portion  48  to elastically press the rising piece  47  in a lateral direction, therefore, the projection piece  24  of the overlapping portion  48  is not deformed nor broken.  
         [0056]    The invention can be embodied in various other manners without departing the spirit or principal features of the invention. The embodiment described above is a mere exemplification in every respect, and is not restrictively construed. The scope of the invention is to be determined solely by the appended claims, and not limited by the description of the specification. All modifications and changes belonging to the range of equivalence of the appended claims are within the scope of the invention.  
         [0057]    The entire disclosure of Japanese Patent Application No. 2001-391493 filed on Dec. 25, 2001 including specification, claims, drawings and summary are incorporated herein by reference in its entirety.