FR2691264A1 - Optical links joining system for coupling to electrical links - has opto-electronic component with fixed coupling able to convert optical signal to electrical signal with several electrical conductors - Google Patents

Abstract

The appts. has a first support (6) and a second support (8). One extremity of the optical contact (2) is connected to the first support and is fixed. The electrical connection (4) is connected to the second support and is terminated by an opto-electronic component (10) which will be optically coupled to the corresponding extremity of the optical component whereas the supports are connected one to the other by appropriate means (9). The component (10) is a photo-emitter or photo-detector. In the case where it is a photo-emitter it converts the electrical signals into optical signals which are then transmitted by the associated optical connection. For the case of the photodetector the signals converted are light and are transmitted through the corresponding electrical connection. Each component is mounted on an element (12) which is supported on a top (14) and with a tubular body (16). The tubular body is open and has two extremities emerging in a housing (22) with base (23). USE - Optoelectronic connection for information transmission systems in aircraft and spacecraft.

Description

SYSTEM FOR CONNECTING OPTICAL BONDS TO
ELECTRICAL CONNECTIONS
DESCRIPTION
The present invention relates to a system for connecting at least one optical link, which is terminated by an optical contact, to at least one electrical connection, which is terminated by an optoelectronic component, this system comprising:
a first support of which each optical contact is solid,
a second support of which each optoelectronic component is integral,
means for fixing the first support to the second support, each optoelectronic component being optically coupled to the corresponding optical contact when the two supports are fixed to one another.

 It is specified that "optoelectronic component" is understood to mean a component capable of converting an electrical signal into a light signal for sending it into the corresponding optical link, or capable of converting a light signal, originating from the corresponding optical link, into a light signal. an electrical signal which is then transmitted by the associated electrical connection.

 In the invention, an electrical connection generally comprises a plurality of electrical conductors whereas an optical connection generally comprises a single optical conductor.

 The invention is particularly applicable to the transmission of information in airplanes and spacecraft.

 Already known from EP-A-0228666 (ALCATEL CIT) corresponding to US-A-4,836,635, a connection system of the kind mentioned above.

 However, this known system is an afocal system which requires two lenses for optically coupling the optoelectronic component to the optical contact.

 The present invention solves the problem of obtaining a good optical gap between each optical contact and the corresponding optoelectronic component without requiring such lenses.

 To solve this problem, the present invention uses precise axial positioning of the optoelectronic component with respect to the optical contact.

 More specifically, the connection system according to this invention, comprising the supports and the fixing means referred to above, is characterized in that it further comprises, for each optical contact, a means of catching the axial play. (That is to say, the play along the axis of the optical contact) that the first support is likely to have with respect to the second support, to have constantly the same determined interval between the optical contact and the corresponding optoelectronic component.

 Thus, when the supports are connected to each other, there is no relative movement between the optical contact and the associated component: a constant distance (preferably optimized) is maintained between them which form, in a way, an optical connector "flowing" in the system, along the axis of the optical contact.

 Preferably, so that there are no constraints on the side of the optical contact or contacts, each optical contact is fixed to the first support, the means of catching the corresponding game is placed in the second support and the part of the link electrical lead that leads to the corresponding optoelectronic component is deformable.

 The deformable portion of the electrical connection may be constituted by a flexible electrical circuit or sliding electrical contacts.

According to a particular embodiment of the system which is the subject of the invention, the means of catching up the game comprises:
- A tubular member open at both ends, which is movable in translation in a bore provided in the second support and a first end, located on the side of the first support comprises an outer shoulder, the optoelectronic component being immobilized relative to this body opposite the second end thereof, the optical contact being insertable into this tubular member by the first end thereof, and
- An elastic means which is between the outer shoulder and an internal shoulder formed in the bore, the elastic means allowing a recoil of the optoelectronic component of an amplitude greater than the maximum axial play.

 Then, in a particular embodiment, the optical contact is terminated by a tip, the means of catching the game further comprises an element comprising a base and a tubular body which extends the base and which is open at both ends, the component Optoelectronics being fixed in the base facing the first of these ends, the tubular body being insertable in the tubular member and the endpiece being nsable in the tubular body by the second end thereof, the optical contact comprising a shoulder through which it abuts against the tubular body when the tip is introduced into the tubular body, the latter comprising a means of immobilization relative to the tubular member.

 In a preferred embodiment of the invention, each element is separable from the corresponding tubular member.

The means for immobilizing the tubular body with respect to the corresponding tubular member may comprise at least one peripheral lug, capable of being retracted with the aid of a standard tool for moving the tubular body towards the outside of the tubular body.
The tubular organ

 There is then a modular connection system, the modularity of which allows the replacement of the active element of each link either during faults or to make circuit modifications without dismantling the equipment.

 Finally, the system according to the invention may comprise, in addition to the first and second supports, another support which carries electrical connection means and which is fixed to the second support, on the side where the insertion of each tubular body takes place. , and sufficiently spaced from the second support to allow the establishment in the latter of each element carrying a component and the electrical connection which corresponds to this component comprises a flexible electrical circuit for connecting this component to the electrical connection means .

 It is thus easy to remove a defective component and replace it without having to remove said other support.

The present invention will be better understood on reading the description of exemplary embodiments given hereinafter only by way of indication and in no way limiting, with reference to the appended drawings in which:
FIG. 1 is a schematic view of a particular embodiment of the object system of FIG.
The invention,
FIG. 2 diagrammatically represents an elementary optical connector of the system of FIG. 1,
FIGS. 3, 3A and 3B illustrate diagrammatically the removal of an element which bears a defective optoelectronic component, and
- Figure 4 schematically illustrates the replacement of this element by a new element carrying another component that works properly.

 The particular embodiment of the system according to the invention, which is schematically represented in FIG. 1, is intended to connect a plurality of optical links 2, terminated by end pieces 58, respectively to a plurality of electrical connections 4.

 The system shown in FIG. I comprises a first support 6 and a second support 8.

 One end of each optical link 2 leads to the first support 6 and is fixed to it, as will be seen better later.

 One end of each electrical connection 4 leads to the second support 8 and ends with an opto-electronic component 10 which is intended to be optically cut at the end of the corresponding optical link 2 when the supports 6 and 8 are fixed. to the other by appropriate means 9.

 The component 10 may be a photo-emitter or a photodetector.

In the case where it is a photo-transmitter, it converts the electrical signals, which reach it by the corresponding electrical connection, into luminous signals which are then transmitted by the
Associated optical link.

 In the case where it is a photodetector, it converts the light signals, which it receives from the associated optical link, into electrical signals which are then transmitted by the corresponding electrical link.

 Each component 10 is mounted in an element 12 which comprises a base 14 and a tubular body 16 extending this base 14.

 This tubular body is open at both ends and one of these two ends opens into a housing 18 formed in the base, as seen in Figure 4.

The component 10 is fixed in this housing 18 so that its active part, which emits or detects light, is opposite the opening of
The end of the tubular body that opens into the housing.

 Housing 22, which is intended to respectively accommodate the bases 14, is made on one side 23 of the second support 8.

 These housing s 22 are respectively extended by bores 24 which are parallel to each other and which open on the opposite side 25 of the second support 8, side by which the ends of the optical links are introduced into the second support 8, as the will see later.

 In FIG. 1, it can be seen that each piercing 24 comprises, on the side 23 of the support 8, a part 26 whose diameter is a little smaller than the diameter of the remainder of this piercing, so that it comprises an internal shoulder 27 which is visible on the side 25 of the support 8 and whose function will be explained later.

 Each bore 24 contains a tubular member 28 which is open at both ends and which is slidable in this bore, the outer diameter of this tubular member being thus only slightly less than the diameter of the portion 26 of the bore.

The end of the tubular member 28, which is located on the side 25 of the support 8, has an outer peripheral shoulder 30 which is opposite
The corresponding internal shoulder 27.

 A "clip" 32 (elastic means) carrying peripheral pins 34 is mounted on the tubular body 16 of each element 12.

Each tubular body 16 is inserted into a tubular member 28, on the side 23 of the support 8, and the lugs of the clip 32 that it carries cooperate with a small internal shoulder of the tubular member to prevent
The outlet of the tubular body 16 after its insertion into the corresponding tubular member.

 An elastic means 36 is placed between each shoulder 30 and the corresponding shoulder 27, this elastic means being, in the illustrated embodiment, a helicoidal spring that passes through the tubular member having this shoulder 30.

In Figure 1, there is shown symbolically, for a better understanding of
The invention, an optical link not connected to the corresponding electrical connection and another optical link which is connected to the corresponding electrical connection, when, in fact, the connections are made simultaneously.

FIG. 1 shows that, in the absence of corresponding optical contact, each base 14 is at the bottom of its housing 22 and that each shoulder 30 is substantially at the level of
The end of the corresponding bore 24, which end is located on the side of the support 8.

 The system shown in FIG. 1 also comprises an interconnection card 38 which is for example a printed multi-layer circuit and which is fixed to the support 8, on the side 23 thereof, by means of two spacers such as the spacer 40.

 These two spacers are located on both sides of the housing unit 22.

 The gap between the multilayer circuit 38 and the side 23 of the support 8 is sufficient to allow the passage of an element 12 extracted from the support 8 as will be seen later, when its component 10 is defective, and the establishment of a new element.

 The multilayer circuit 38 carries pins 42 to which the components 10 are connected and may furthermore carry electrical components (not shown).

 Each component 10 comprises a plurality of pins 44 which allow the supply of electrical activation signals of this component, if it is a photo-transmitter, or the output of the electrical signals produced by this component, it is a photo-detector.

 The pins 44 are connected to homologous pins 42 of the multilayer circuit 38 via, for example, a flexible circuit 46 having electrically conductive parallel tracks 48, each track 48 connecting a pin 44 to a pin 42.

 Thus, each electrical connection 4 goes from an opto-electronic component 10 to electrical signal processing means (not shown) via a flexible circuit 46, pins 42 and unrepresented electrical conductors.

 The first support 6 is intended to be placed facing the face 25 of the second support 8 and fixed to the latter with screws 9.

 It can be seen in FIG. 1 that the first support also carries guide pins 50 which, when the supports are connected, pass through the support 8 provided with holes for this purpose.

 Each optical link 2 comprises an optical fiber 52 and comprises, at its end intended to be connected to the corresponding electrical connection, an optical contact 54 forming an elementary mile optical connector 54 provided with a shoulder 56 and terminated by a tip 58.

 The fiber 52, the optical contact 54 and the tip 58 have a common axis which is denoted X.

 The elementary connectors 54 are parallel to each other and are fixed to the first support 6, for example by unrepresented latching means.

 Each elementary connector 54 is intended to be inserted into the corresponding tubular member 28, the end piece 58 of this connector 54 being provided, for its part, to be inserted into the tubular body 16 fixed in this tubular member, until that the shoulder 56 of the connector 54 comes into abutment against this tubular body 16.

 The quality of the coupling of each optical fiber 52 and the corresponding component 10 requires, on the one hand, to place the end of the fiber at a predetermined distance from this component without it being in contact with the latter, which would damage the fiber and the component, and on the other hand to maintain constant this distance called far more interval I.

This is why, as can be seen in FIG. 2, the distance D between the shoulder 56 of the connector 54 and the end of the fiber (end of
The tip 58) is precisely defined so that it is slightly smaller than the distance D1 between the end of the tubular body 16 and the bottom of the housing 18 (FIG. 4), this distance D1 being also precisely defined. , with I = D1-D.

It can be seen in FIG. 1 that, when the optical links are connected to the electrical connections, each shoulder abuts against the corresponding tubular body, which causes a recess of the associated base (towards the outside of its housing 22).
Then, each spring 36 exerts on the corresponding shoulder 30 a force which tends to bring this shoulder towards the side 25 of the support 8, in the vicinity of which it was before the connection of the
Links.

Each spring 36 makes it possible to compensate for the axial play of the first support 6 (to which the connectors 54 are fixed) on the element 12 corresponding to this spring.
More precisely, in order to keep the interval I mentioned above constant despite the longitudinal positional deviations likely to occur between the supports 6 and 8 during the use of the system, it has therefore been provided, in accordance with the invention, a catch-up axial clearance, in the support 8 and for each base 14.

 This play clearance is achieved thanks to the spring 36, in cooperation with the tubular member 28 which forms a guide sleeve of the optical contact 52 and the tubular body 16, to allow simultaneous longitudinal movements thereof, without relative movement between they, the interval I remaining constantly equal to D1-D.

 We will now explain the replacement of a defective component.

 To perform this replacement, we first separate the support 6 from the support 8 to remove the connectors 54 and thus the end pieces 58 of the second support 8 <Figure 2).

 Then, after having placed the second support 8, provided with the multilayer circuit 38, on a working surface 59, the element 12, which carries the defective component, is pushed out of the second support.

 This is accomplished (FIG. 3) by means of a suitable standard tool 60, of elongated tubular shape, the end of which is inserted, by the side 25 of the second support 8, between the tubular member 28, where finds the tubular body 16 of the element 12 considered, and this tubular body 16.

 This tool 60 is provided so that its end comes into contact with the pins 34 to fold them.

 FIG. 3A shows the tool 60 already engaged in the annular space delimited by the member 28 and the body 16, just before contact with the lugs 34.

 FIG. 3B shows the tool 60 having folded the lugs 34.

 Thus, by exerting a sufficient force F on the lugs 34, these latter are retracted, by varying their flexibility, to bring them to a diameter smaller than the internal diameter of the tubular member 28 at first and, in a second step the tubular body 16 is pulled out of the tubular member 28 and thus the element 12 of the support 8.

 After which, the flexible circuit 46 associated with the defective component is disconnected from the corresponding pins 42.

 This is done by desoldering, assuming that the conductive tracks 48 of the flexible circuit were soldered to the pins 42.

 It is then possible to remove the defective component mounted in its element 12.

 Next, a new element 12 is inserted into the support 8 instead of the one that has been removed, this new element carrying a new component 10 that functions correctly.

 The new element is blocked in the corresponding tubular member by means of the lugs that this new element comprises and the corresponding pins 42 are welded to the tracks of the flexible circuit associated with the new component.

 Beforehand, of course, the new element 12 and the new component 10 (FIG. 4) carrying its flexible circuit 46 are assembled.

 To do this, the new component is introduced into the housing 18 of the element, with a suitable orientation which can be identified by means of angular deflection means (eg lug on the component and corresponding housing in the base) not shown.

 Before its introduction, the new component is provided at its periphery with a resilient split ring 66 for centering the component in its housing and, after it has been put in place in this housing, the latter is closed and immobilized. component using, for example, a layer 68 (Figure 3) of epoxy thermo-conductive and electro-insulating, intended to promote heat exchange between the component casing and the outside of the support 8.

Claims (8)

 A system for connecting at least one optical link (2) terminated by an optical contact (54) to at least one electrical connection (4) which is terminated by an optoelectronic component (10). comprising:  a first support (6) of which each optical contact (54) is integral,  a second support (8) of which each optoelectronic component (10) is integral,  means (9) for fixing the first support to the second support, each optoelectronic component (10) being optically coupled to the corresponding optical contact (54) when the two supports are fixed to each other, this system being characterized by it furthermore comprises, for each optical contact, means (28, 36) for compensating for the axial clearance that the first support (6) is likely to have with respect to the second support (8), so as to have a constant determined interval between this optical contact and the corresponding optoelectronic component.  2. System according to claim 1, characterized in that each optical contact (54) is fixed to the first support (6), in that the means (28, 36) for catching the corresponding game is placed in the second support (8). ) and in that the portion (46) of the electrical connection (4) which leads to the corresponding optoelectronic component (10) is deformable.  3. System according to claim 2, characterized in that the means of catching the game comprises:  - a tubular member (28) open at both ends, which is movable in translation in a bore (24) provided in the second support (8) and a first end, located on the side of the first support (6), comprises a outer shoulder (30), the optoelectronic component (10) being immobilized with respect to this member, opposite the second end thereof, the optical contact being insertable into this tubular member by the first end thereof, and  - an elastic means (36) which is between the outer shoulder (30) and an inner shoulder (27) formed in the bore (24), this elastic means allowing a recoil of the optoelectronic component of an amplitude greater than the axial play. maximum.  4. System according to claim 3, characterized in that the optical contact (54) is terminated by a tip (58), in that the means of catching the game further comprises an element (12) having a base (14). and a tubular body (16) which extends the base (14) and which is open at both ends, the optoelectronic component (10) being fixed in the base (14) opposite the first of these ends, the body tubular (16) being insertable in the tubular member (28) and the tip (58) being insertable into the tubular body (16) by the second end thereof, the optical contact having a shoulder (56) by Which it comes into abutment against the tubular body (16) when the end piece (58) is introduced into this tubular body (16), the latter comprising means (34) of immobilization with respect to the tubular member (28).  5. System according to claim 4, characterized in that the element (12) is separable from The tubular member (28).  6. System according to claim 5, characterized in that the immobilizing means comprises at least one peripheral lug (34), capable of being retracted with a standard tool to move the tubular body (16) towards the outside of the tubular member (28).  7. System according to any one of claims 2 to 6, characterized in that the deformable portion of the electrical connection (4) is constituted by a flexible electrical circuit (46).  8. System according to any one of claims 4 to 6, characterized in that it further comprises another support (38) which carries electrical connection means (42) and which is fixed to the second support (8), on the side (23) where the insertion of each tubular body (16) takes place, and sufficiently spaced from this second support to allow the introduction, in the latter, of each element (12) carrying a component (10), and in that the electrical connection (4) corresponding to this component comprises a flexible electrical circuit (46) for connecting this component (10) to the electrical connection means (42).