JP4087587B2 - Mounting structure of optical / electrical composite device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure of an optical / electrical composite apparatus for mounting an optical / electrical composite board in which optical wiring and electrical wiring are mixed on a backplane of a bookshelf type rack.
[0002]
[Prior art]
Along with the high-speed processing of electronic information equipment, it has become necessary to transmit not only electrical signals but also optical signals within the apparatus. As such an optical signal transmission medium, an optical fiber cable is used for connection between optical devices. In this case, when the number of optical wirings increases, these optical fiber cables are bonded onto a flexible film to form a flexible optical wiring board (hereinafter referred to as a fiber sheet), and an optical connector is attached to the tip of the optical fiber cable. The optical wirings are connected through optical connectors.
[0003]
In a conventional optical / electrical device mounting structure, only electrical wiring is formed on the backplane provided on the back of the rack. Therefore, in order to make an optical connection between the optical and electrical composite boards mounted vertically on the backplane, a hole is made in a required portion of the backplane and the rack is connected via an optical connector arranged so as to face the hole. This is carried out by a fiber sheet disposed on the back side of the back plate, and has a configuration independent of the back plane on which only electrical wiring is formed.
[0004]
FIG. 7 is a perspective view showing a conventional mounting structure 1 for an optical / electrical composite apparatus. This will be described with reference to FIG. 1. A reference numeral 2 denotes a bookshelf rack formed in a square tube shape, and a plurality of cooling holes 3 that are also not shown but also have guide rails are provided. It has been. Reference numeral 39 denotes a back plane, which is provided so as to cover the opening on the back side of the rack 2, and above and below the back plane 39, eight square holes 41 arranged in two horizontal rows are formed, Four electrical connectors 13 are fixed between the square holes 41, and an electrical cable 40 is led out from each of the electrical connectors 13.
[0005]
Reference numeral 5 denotes an optical / electrical composite board on which an electronic circuit (not shown) is formed and a fiber sheet (not shown) optically wired is mounted on one surface. An electrical connector 7 electrically connected to the electronic circuit and an optical connector 8 optically connected to the fiber sheet are mounted on the rear end portion of the optical / electrical composite board. Reference numeral 43 denotes a fiber sheet provided on the back side of the backplane 39 and formed with optical wiring. Eight connection portions 43a are led out from the end portions, and the tip portions of the eight connection portions 43a are respectively provided. Optical connectors 42 are optically connected, and these optical connectors 42 are attached to the backplane 39 so as to face the rack 2 from the square holes 41.
[0006]
In such a configuration, when four optical / electrical composite boards 5 (three optical / electrical composite boards 5 are not shown) are inserted from the opening on the front side of the rack 2, the optical / electrical composite board 5 is Then, it is guided to the back side of the rack 2 while being kept upright by a guide (not shown) in the rack 2. When guided to the rear end of the rack 2, the electrical connector 7 and the optical connector 8 of the optical / electric composite board 5 are electrically connected and optically connected to the electrical connector 13 of the backplane 39 and the optical connector 42 of the fiber sheet 43, respectively. Connected. When the optical connector 8 of the four optical / electrical composite boards 5 is optically connected to the optical connector 42 of the fiber sheet 43, the optical optical / electrical composite boards 5 are optically connected to each other via the fiber sheet 43. Is done.
[0007]
[Problems to be solved by the invention]
However, in the mounting structure of the conventional optical / electrical composite apparatus 1 described above, not only the electric cable 40 but also the fiber sheet 43 is disposed in the mounting space on the back side of the backplane 39, so that the rack 2. Since a space for housing the fiber sheet 43 is required on the back side, high-density mounting has been difficult. Further, the space on the back side of the rack 2 is congested and complicated by the electric cables 40 and the fiber sheet 43, making assembly and repair work difficult. Furthermore, since many large square holes 41 for optical connection are formed in the backplane 39, the wiring area of the electrical wiring in the backplane 39 is limited, and the mechanical strength of the backplane 39 cannot be obtained. There was also a problem.
[0008]
The present invention has been made in view of the above-described conventional problems, and a first object is to enable high-density mounting. A second object is to facilitate assembly work and repair work. A third object is to improve the mechanical strength of the backplane.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides a plurality of optical / electrical composite boards on which optical wiring and electrical wiring are mounted, a bookshelf rack that accommodates the plurality of optical / electrical composite boards, and the bookshelf. A light plane comprising a backplane provided on the back of the mold rack and electrically connecting the plurality of optical / electrical composite boards, and a flexible optical wiring board optically connecting the optical / electrical composite boards. In the mounting structure of the electrical composite device, the flexible optical wiring board is mounted on the surface of the backplane facing the rack, and the optical connector and the electrical connector are mounted on the optical / electrical composite board. and optical connections and electrically connected to the electrical connector, the plug-Uni said light-electrical composite board to the backplane The optical connector of the backplane is movably supported in the surface direction of the backplane, and the ferrule in the optical connector and the ferrule of the optical connector of the optical / electrical composite board are engaged with each other. One of the ferrules is supported by the optical connector so as to be movable in the vertical direction of the backplane .
Therefore, there is no flexible optical wiring board behind the back side of the backplane. Further, by plugging in the optical / electrical composite board, the optical connector and the electrical connector of the optical / electrical composite board are optically connected and electrically connected to the optical connector and the electrical connector of the backplane in a lump. Further, when the ferrule of the optical connector of the optical / electrical composite board is fitted to the ferrule of the optical connector of the backplane, the optical connector can move in the surface direction of the backplane and the insertion / extraction direction of the optical / electrical composite board.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which a rack is shifted in a mounting structure 1 for an optical / electric composite device according to the present invention, and FIG. 2 is a perspective view of a main part showing a state in which the optical / electric composite board is also mounted on a backplane. FIG. 3 is an enlarged sectional view of the optical connector of the optical / electrical composite board and the optical connector of the backplane. FIG. 4 is a graph showing the relationship between the radius of curvature and the amount of optical transmission loss when the fiber is bent. 5A is a cross-sectional view showing the mounting structure of the optical connector mounted on the backplane, FIG. 5B is a plan view for explaining the movement of the optical connector, and FIG. 6 is the optical / electric composite board. FIG. 5 is a cross-sectional view of the main part for explaining the fitting operation between the optical connectors of the backplane and the backplane.
In these drawings, the same or equivalent members described in the prior art shown in FIG. 7 described above are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.
[0014]
The feature of the present invention is that, as shown in FIG. 1, the fiber sheet 11 is mounted on the surface 10A of the backplane 10 facing the inside of the rack 2 by bonding or screwing, and only the electrical connector 13 is mounted on the backplane 10. Instead, the optical connector 14 is mounted.
[0015]
As shown in FIG. 3, the optical connector 14 mounted on the backplane 10 includes an MT ferrule 27, a ferrule holder 26 that holds and fixes the MT ferrule 27, and a holder 25 to which the ferrule holder 26 is attached. It is constituted by. The holder 25 is formed in a substantially rectangular tube shape, is provided with a notch 25a in the lower part, and a pair of elastic engagement pieces 25b, 25b facing each other on both sides projecting upward in the figure. Claw portions 25c and 25c facing each other are provided at the front ends of the combined pieces 25b and 25b.
[0016]
The optical connector 14 is mounted on the backplane 10 with the holder 25 standing on the backplane 10 so that the MT ferrule 27 is oriented upward in the drawing, that is, perpendicular to the backplane 10. The connecting portion 11a led out from the fiber sheet 11 is optically connected to the MT ferrule 27 through the notch 25a. Therefore, the connecting portion 11a is in a curved state in a side view, and the curvature radius R is set to be a predetermined value or more. That is, FIG. 4 shows the relationship between the radius of curvature when the optical fiber is bent and the amount of transmission loss of the optical fiber. As can be seen from this figure, the optical transmission loss is not affected by setting the radius of curvature to 20 mm or more in the case of a multimode fiber and to 10 mm or more in the case of a single mode fiber. Therefore, the radius of curvature R is also set to be equal to or greater than these predetermined values so that the optical connecting portion 11a is bent in a range that does not affect the optical transmission loss.
[0017]
The optical transmission loss due to the radius of curvature differs depending on the type of optical fiber (multimode or single mode or the refractive index ratio between the core material and the cladding material of the fiber) and the wavelength of light used. 4 shows an optical fiber used as a communication optical fiber (with a cladding diameter of 125 μm, a core diameter of 50 μm in multimode, 10 μm in single mode, and a refractive index ratio of 0.3 to 0.3). %). For this reason, it goes without saying that the radius of curvature of the allowable loss range suitable for the purpose can be set.
[0018]
Next, the structure of the optical connector 8 mounted on the optical / electrical composite board 5 will be described with reference to FIG.
The optical connector 8 is generally composed of an MT ferrule 22, a ferrule holder 21 that supports the MT ferrule 22 so as to be movable in the axial direction, and a holder 20 that holds the ferrule holder 21. A compression coil spring 23 is elastically mounted in a hollow portion formed in the ferrule holder 21, and the MT ferrule 22 is biased downward in the figure by the elastic force of the compression coil spring 23, and the MT ferrule 22 and the ferrule Due to the engagement with the holding body 21, dropping from the ferrule holding body 21 is regulated.
[0019]
The ferrule holder 21 has a pair of elastic engagement pieces 21a, 21a facing each other and projecting downward in the figure, and claw portions 21b facing each other at the distal ends of the elastic engagement pieces 21a, 21a. , 21b, and a through hole 21c is formed at the bottom. The holder 20 is formed in a bottomed rectangular tube shape, and a pair of elastic engagement pieces 20a, 20a facing each other is provided on both sides so as to protrude downward in the figure, and the distal ends of these elastic engagement pieces 20a, 20a. Are provided with claw portions 20b, 20b facing each other, and a through hole 20c is formed at the bottom.
[0020]
In such a configuration, the ferrule holder 21 accommodated in the holder 20 is engaged with the claw 20b of the elastic engagement piece 20a of the holder 20 and the claw 21b of the elastic engagement piece 21a of the ferrule holder 21. As a result, it is held by the holder 20. In this state, a gap 24 formed at a distance L is provided between the bottom of the ferrule holder 21 and the bottom of the holder 20. The connecting portion 6a led out from the fiber sheet 6 (see FIG. 2) mounted on the optical / electrical composite board 5 is introduced into the ferrule holder 21 through the through holes 20c and 21c of the holder 20 and the ferrule holder 21. And is optically connected to the ferrule 22. By fixing the side part of the holder 20 on the optical / electrical composite board 5, the MT ferrule 22 is oriented parallel to the optical / electrical composite board 5, and the connection part 6a of the fiber sheet 6 is optical / electrical. Since it extends along the composite board 5, it does not bend.
[0021]
Next, a structure for attaching the optical connector 14 to the backplane 10 will be described with reference to FIG.
In FIG. 4A, corresponding to the position where the optical connector 14 is mounted, mounting holes 10a and 10a are drilled in the backplane 10, and the diameter D of the mounting hole 10a is larger than the diameter d of the bolt 30. A gap 32 is provided between the mounting hole 10 a and the bolt 30. As will be described later, the size of the gap 32 is such that when the optical connector 14 moves in the range of the gap 32, the engagement piece 25 b of the optical connector 14 is replaced with the engagement piece 20 a and the engagement piece 21 a of the optical connector 8. It is set to the range that can be engaged in between.
[0022]
In such a configuration, the bolt 30 is inserted through the hole 25d of the holder 25 of the optical connector 14, the insertion hole 10a of the backplane 10 is further inserted, and the nut 31 is screwed into the tip portion, whereby the optical connector 14 is inserted. Is attached to the backplane 10. The optical connector 14 thus mounted has a gap 32 between the mounting hole 10 a and the bolt 30, so that the backplane 10 is in the range of the gap 32 in the surface direction of the backplane 10. It is supported movably. That is, as shown in FIG. 4B, when the bolt 30 moves in the mounting hole 10a from the position indicated by the two-dot chain line to the position indicated by the solid line, the holder 25 of the optical connector 14 is also indicated by the two-dot chain line. To the position indicated by the solid line.
[0023]
Next, an optical connection operation in the mounting structure 1 of the optical / electrical composite apparatus having such a configuration will be described.
As shown in FIG. 1, when four optical / electrical composite boards 5 (one optical / electrical composite board 5 is not shown) are inserted from the opening on the front side of the rack 2, the optical / electrical composite board 5 is inserted. Is guided to the back side of the rack 2 while being kept upright by a guide (not shown) in the rack 2. When guided to the rear end of the rack 2, the electrical connector 7 and the optical connector 8 of the optical / electric composite board 5 are electrically connected and optically connected to the electrical connector 13 and the optical connector 14 mounted on the backplane 10, respectively. Is done.
[0024]
In this way, the optical / electrical composite board 5 that is electrically connected and optically connected is mounted vertically on the backplane 10 and is pulled out in the direction opposite to the insertion direction, so that the electrical connection and the optical connection are released. It has a plug-in unit structure that can be removed from the opening on the front side. Therefore, the optical connector 8 and the electrical connector 7 of the optical / electric composite board 5 are optically connected to the optical connector 14 and the electrical connector 13 of the backplane 10 by plug-in operation of the optical / electric composite board 5. And because it is electrically connected, usability is improved.
[0025]
Next, the state when the optical connector 8 of the optical / electrical composite board 5 is optically connected to the optical connector 14 mounted on the backplane 10 will be described with reference to FIG.
In FIG. 5A, the optical / electrical composite board 5 inserted into the rack 2 is further inserted from the state in which the MT ferrule 22 of the optical connector 8 faces the MT ferrule 27 of the optical connector 14, thereby the optical connector 8. Moves in the direction of arrow A in the figure. As shown in FIG. 2B, the engagement piece 25b of the optical connector 14 enters between the engagement piece 20a and the engagement piece 21a of the optical connector 8, and the MT ferrule 27 and the MT ferrule 22 come into contact with each other. .
[0026]
Further, when the optical / electrical composite board 5 is inserted, the optical connector 8 moves in the direction of arrow A in the figure as shown in FIG. The engagement between the claw 20b of the engagement piece 20a and the claw 21b of the engagement piece 21a is released. Accordingly, since the ferrule holder 21 of the optical connector 8 becomes movable with respect to the holder 20 of the optical connector 8, the MT ferrule 22 is pressed and moved by the MT ferrule 27 in the direction of arrow B in the figure. Therefore, the compression coil spring 23 is compressed, and the MT ferrule 22 is pressed toward the MT ferrule 27 by the elastic force of the compression coil spring 23, and the MT ferrule 27 and the MT ferrule 22 are fitted by this pressing force. Connect optically. At the same time, the claw 25c of the engaging piece 25b of the optical connector 14 engages with the claw 21b of the engaging piece 21a of the optical connector 8, as shown in FIG. Is locked to the holder 25 of the optical connector 14. Accordingly, the state of optical connection between the MT ferrule 27 and the MT ferrule 22 is maintained.
[0027]
Further, in FIG. 5C, when the MT ferrule 27 and the MT ferrule 22 are fitted, the optical connector 14 is supported so as to be movable in the surface direction of the backplane 10 as described above with reference to FIG. As a result, the position of the MT ferrule 27 of the optical connector 14 is finely adjusted, so that the fitting is reliably performed.
[0028]
In general, in a structure in which a plurality of electrical connectors 7 and optical connectors 8 mounted on the optical / electrical composite board 5 are connected to a plurality of electrical connectors 13 and optical connectors 14 mounted on the backplane 10 of the rack 2, There are slight variations in the joining positions between these electrical connectors 7 and 13 and between the optical connectors 8 and 14. In particular, since connection between optical connectors requires high-precision alignment of μm or less, the optical / electrical composite board 5 can be collectively connected to the optical connector and the electrical connector by plug-in operation. A structure that absorbs this variation is required. As in the present invention, the optical connector 14 can move in the horizontal direction on the surface of the backplane 2 and the optical connector 8 can move in the vertical direction, so that variations can be absorbed.
[0029]
In addition, when the MT ferrule 22 of the optical connector 8 moves, the connection portion 6a optically connected to the MT ferrule 22 is deformed from the initial state, but the fiber sheet is used so that the deformation does not cause an optical transmission loss. The fixing position to the optical / electric composite board 5 and the total length of the connecting portion 6a are taken into consideration. Similarly, when the optical connector 14 moves in the plane direction of the backplane 10, the connection portion 11a optically connected to the MT ferrule 27 is deformed from the initial state, but the deformation does not cause an optical transmission loss. The fixing position of the fiber sheet 11 to the backplane 10 and the total length of the connection portion 11a are considered.
[0030]
As described above, the fiber sheet 11 is mounted on the inner surface of the backplane 10, and not only the electrical connector 13 but also the optical connector 14 is mounted on the surface 10 </ b> A facing the inner side of the rack 2 of the backplane 10. Since there is no need for a space for housing the fiber sheet 11 in the mounting space on the back side, high-density mounting is possible. Further, since the fiber sheet 11 is not present behind the back side of the rack 2, assembly work and repair work are facilitated. Furthermore, since it is not necessary to provide a large hole for optical connection in the backplane 10, the mechanical strength of the backplane 10 can be improved.
[0031]
In the present embodiment, the optical connection between the optical connectors 8 and 14 and the ferrules 22 and 27 is the connection portions 6a and 11a provided on the fiber sheets 6 and 11, but the optical fiber itself may be peeled off. Good. Further, although the ferrules 22 and 27 are MT ferrules that are multi-core ferrules, similar effects can be obtained when single-core ferrules such as MU ferrules and SC ferrules are used. Further, in order to move the optical connector 14 in the surface direction of the backplane 10, the mounting hole 10 a formed larger than the diameter of the bolt 30 is provided on the backplane 10 side, but provided on the holder 25 side of the optical connector 14. Also good. Further, although the MT ferrule 22 of the optical connector 8 is movable, the MT ferrule 27 of the optical connector 14 may be movable.
[0032]
【The invention's effect】
As described above, according to the present invention, since there is no need for a space for housing the flexible optical wiring board on the back side of the rack in the mounting space on the back side of the backplane, high-density mounting is possible. Further, since the flexible optical wiring board is not provided in the space on the back side of the rack, assembly work and repair work are facilitated. Furthermore, since it is not necessary to provide a large hole for optical connection in the backplane, the mechanical strength of the backplane can be improved. Also, by plugging in the optical / electrical composite board, the optical connector / electrical connector on the optical / electrical composite board can be optically and electrically connected to the optical connector and electrical connector on the backplane at the same time. Will improve. In addition, the fitting state between the ferrule of the optical connector of the optical / electrical composite board and the ferrule of the optical connector of the backplane becomes good, and the loss of optical transmission is reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which a rack is shifted in a mounting structure for an optical / electrical composite apparatus according to the present invention.
FIG. 2 is a perspective view of a main part showing a state in which an optical / electrical composite board is mounted on a backplane in the optical / electrical composite device mounting structure according to the present invention;
FIG. 3 is an enlarged cross-sectional view showing an optical connector of an optical / electrical composite board and an optical connector of a backplane in the mounting structure of the optical / electrical composite device according to the present invention.
FIG. 4 is a diagram showing the relationship between the radius of curvature and the amount of optical transmission loss when a fiber is bent.
5A is a cross-sectional view showing a mounting structure of an optical connector mounted on a backplane in the optical / electrical composite device mounting structure according to the present invention, and FIG. 5B is a movement of the optical connector. It is a top view for demonstrating.
FIG. 6 is a cross-sectional view of the main part for explaining the fitting operation between the optical connectors of the optical / electrical composite board and the backplane in the mounting structure of the optical / electrical composite device according to the present invention.
FIG. 7 is a perspective view showing a mounting structure of a conventional optical / electrical composite apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mounting structure of optical / electrical composite apparatus, 2 ... Rack, 5 ... Optical / electrical composite board, 6, 11 ... Fiber sheet, 6a, 11a ... Connection part, 7, 13 ... Electrical connector, 8, 14 ... Optical connector DESCRIPTION OF SYMBOLS 10 ... Backplane, 10a ... Mounting hole, 20, 25 ... Holder, 21, 26 ... Ferrule holder, 22, 27 ... MT ferrule, 23 ... Compression coil spring, 30 ... Bolt.

Claims (1)

A plurality of optical / electrical composite boards on which optical wiring and electrical wiring are mounted, a bookshelf type rack for storing the plurality of optical / electrical composite boards, and the plurality of optical / electrical boards provided on the back of the bookshelf type rack In the mounting structure of an optical / electrical composite apparatus, comprising: a backplane that electrically connects the electrical composite boards; and a flexible optical wiring board that optically connects the optical / electrical composite boards. The board is mounted on the surface of the backplane facing the inside of the rack, the optical connector and the electrical connector are mounted on the optical / electrical composite board, and the optical connector and the electrical connector are optically connected and electrically connected . The optical / electrical composite board has a plug-in unit structure with respect to the backplane, and the backplane light The connector is supported so as to be movable in the plane direction of the backplane. When the ferrule in the optical connector and the ferrule of the optical connector of the optical / electrical composite board are fitted, one of these ferrules is attached to the optical connector. A mounting structure for an optical / electrical composite device, characterized in that it is supported so as to be movable in the vertical direction .

Images