NL2002752C2

NL2002752C2 - Optical connector cleaning device and method.

Info

Publication number: NL2002752C2
Application number: NL2002752A
Authority: NL
Inventors: Antonie Hoog
Original assignee: Attema Kunststoffenind
Priority date: 2009-04-15
Filing date: 2009-04-15
Publication date: 2010-10-18

Description

P29847NL00/ME

Optical connector cleaning device and method FIELD OF THE INVENTION

5 The invention relates to the field of optical connectors, and more specifically to cleaning of the light transmitting optical coupling faces of the optical fibers in the optical connectors.

BACKGROUND OF THE INVENTION

10

In optical fiber networks, fiber termination units (FTUs) are installed at the premises of a customer or user, which may be a business building or private home, for example.

Technical developments in this field are also referred to as fiber-to-the-home (FTTH) networks. In an (e.g. wall-mounted) FTU, an incoming fiber cable is terminated, which 15 involves a mechanical fixing of the cable, a storage of excess length of the cable, a storage of fiber connections, provision of optical connectors, etc.

An optical connector of the FTU may be connected to an associated and matching optical connector of a further optical fiber, or may e.g. be connected to an optical connector of a processing and/or converting module, such as an opto-electric converter, also indicated as 20 a network terminator (NT). The NT may have a housing separate from the FTU, and also may have a power supply separate from the FTU. The NT enables e.g. data, voice and CATV services to be provided through the fiber optical network.

Optical coupling of an NT to an FTU may be made through a patch cable, however, preference is given to a solution in which the NT and the FTU fit together in such a way that 25 they visually form a unit. This implies that apart from an optical coupling, also a mechanical coupling between the NT and the FTU is to be established. For this purpose, each of the NT and the FTU must have a suitable mechanical interface enabling the intended optical and mechanical coupling.

A coupling of optical fibers is to be made very accurately, since the light transmitting 30 part of an optical fiber has a diameter in the order of micrometers, to be aligned with the light transmitting part of the optical fiber to be coupled. For a reliable optical connection, the optical coupling faces of the optical fibers to be coupled must also be subjected to a predetermined contact pressure.

In private homes in particular, a user who couples optical connectors, such as by 35 installing an NT on an FTU, may be expected neither to have a technical skill, nor to have a -2- manipulative skill. Therefore, any coupling between optical connectors should be extremely simple, and allowing only one way of making the coupling. For this purpose, the interface between the optical connectors should be determined univocally both in an optical sense and in a mechanical sense.

5 In the case of coupling of optical fibers, the coupling faces of the respective optical connectors must be clean in order that a proper optical connection can be made with a negligible or acceptable loss of light, a minimum refraction, and a minimum reflection at the optical interfaces. Here, a problem is present in particular, but not exclusively, at the optical connector of the FTU, since the FTU may have been installed a long time, even years, in a 10 building before an NT or other device having an optical connector is coupled to an optical connector of the FTU. On the other hand, an NT or other device normally is made and bought a short time before its installation, and a simple protective tape over the optical coupling face of the optical connector thereof may provide a sufficient preventive measure to avoid contamination of the optical coupling face.

15 If at least one of the optical coupling faces of an optical connection is contaminated, e.g. by dust or grease, a cleaning is mandatory, using specially designed cleaning materials in a predetermined manner. A skilled person who has been trained to clean optical coupling faces may perform the cleaning task to obtain a desired result. Several hand-held devices for cleaning optical coupling faces have been proposed and marketed. Reference is e.g. made to 20 EP 1 300 709, and to devices marketed under the names of FerruleMate, CLETOP and ReelCleaner using cleaning tapes wiping an optical coupling face, with or without the use of cleaning agents such as alcohol. Further, cleaning sticks are used for wiping an optical coupling face.

The process of cleaning, when using the hand-held devices, is unsuitable to be 25 performed by a lay person, or unskilled person, because of the high accuracy of hand movement required to position the cleaning part of the device on the coupling face and to apply a required contact pressure between the cleaning part and the optical coupling face, and because of the expert check of the degree of cleanliness required which cannot be judged by an unskilled person.

30 According to the above, a problem exists when an unskilled person needs to clean an optical end face of an optical connector in a satisfactory way.

SUMMARY OF THE INVENTION

35 It would be desirable to provide a device and method for cleaning of an optical coupling face. It would also be desirable to provide a device and method for cleaning of an optical coupling face by an unskilled person, or an end-user.

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To better address one or more of these concerns, in a first aspect of the invention a cleaning device is provided for use in cleaning an optical coupling face of an optical connector assembly, the optical connector assembly comprising a first optical connector having a first optical coupling face, and being connected to a first mechanical interface, and a second 5 optical connector having a second optical coupling face, and being connected to a second mechanical interface, the first mechanical interface and the second mechanical interface being adapted to be coupled to each other in a predetermined way, wherein the cleaning device comprises a cleaning tool configured for cleaning the optical coupling face, and wherein the cleaning device also comprises at least one of the first mechanical interface and 10 the second mechanical interface.

In the present invention, the inventor has realized that the mechanical coupling of the first optical connector with the second optical connector by coupling the first mechanical interface with the second mechanical interface brings about an accurate positioning of the optical coupling faces of the first and second optical connectors relative to each other. Also, 15 this coupling brings about a predetermined contact pressure between the optical coupling faces. This contact pressure is determined by a fixed positioning of the first optical connector relative to the second optical connector, where at least one of the optical coupling faces of the first and the second optical connectors is mounted movably against the pressure of a spring or similar functioning element relative to the corresponding optical connector. When the 20 optical coupling faces are coupled, the movable optical coupling face is moved against the pressure of the spring of similar functioning element to generate a predetermined contact pressure.

Both results, an accurate positioning and a predetermined contact pressure, can be reached by anyone effecting the coupling. Now, by substituting the first optical connector or 25 the second optical connector by a cleaning device, while providing the cleaning device with the first or second mechanical interface, respectively, both an accurate positioning of the cleaning tool of the cleaning device relative to the optical coupling face to be cleaned can be attained, and a predetermined contact pressure between the cleaning tool and the optical coupling face to the cleaned can be attained. Also, the movement leading to the contact of 30 the cleaning tool with the optical coupling face to be cleaned will take place in a predetermined way, thus avoiding any damage from the cleaning tool to the optical coupling face.

Mounting the cleaning device thus has been made equally simple and effective as mounting an optical connector, and a guaranteed degree of cleanliness of a coupling face can 35 be reached by any skilled or unskilled person. After cleaning, the cleaning device may be removed and substituted by an optical connector, possibly including a housing containing a specific processing and/or converting module.

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In another aspect of the invention, a method of cleaning an optical coupling face of an optical connector assembly is provided, the optical connector assembly comprising a first optical connector having a first optical coupling face, and being connected to a first mechanical interface, and a second optical connector having a second optical coupling face, 5 and being connected to a second mechanical interface, the first mechanical interface and the second mechanical interface being adapted to be coupled to each other in a predetermined way, the method comprising: providing a cleaning device comprising a cleaning tool configured for cleaning the optical coupling face, wherein the cleaning device also comprises at least one of the first mechanical interface and the second mechanical interface; coupling 10 the cleaning device to the optical connector comprising the optical coupling face to be cleaned; and cleaning the optical coupling face with the cleaning tool of the cleaning device.

These and other aspects of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like 15 parts.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 depicts a perspective view, taken from a low point of view, of a part of a wall-20 mountable housing having first optical connectors.

Figure 2 depicts a perspective view, taken from a high point of view, as seen in the direction of arrow II in Figure 3, of a front, first lateral, and top side of a movable housing having a second optical connector to be connected with one of the first optical connectors.

Figure 3 depicts a perspective view, taken from a high point of view, as seen in the 25 direction of arrow III in Figure 2, of a back, second lateral, and top side of the movable housing of Figure 2.

Figure 4 depicts a perspective view of the wall-mountable housing of Figure 1 with a movable housing of Figures 2 and 3 mounted on the wall-mountable housing.

Figure 5 depicts a perspective view, taken from a high point of view, of a cleaning 30 device in an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In the description of embodiments, general indications “high”, “low", “front”, “back”, 35 “lateral”, “top”, “bottom”, “below”, “upwards”, etc. are used to indicate one particular orientation of embodiment parts. This particular orientation may be considered as a practical -5- orientation in practical use of the invention. However, various other orientations are possible without departing from the basic inventive idea.

Figure 1 shows a part of a housing 2, such as a cover part. The housing 2 may be wall-mountable. Figure 1 shows a front side 2a, a lateral side 2b, and a bottom side 2c of the 5 housing 2. The housing 2 has a basic rectangular shape with rounded edges and corners, and comprises a rectangular recessed part 4. The recessed part 4 basically is defined by two surfaces 6 and 8, respectively, oriented at right angles relative to each other.

A first one of these surfaces, top surface 6, comprises two rectangular openings 10 which can be closed by respective covers 12 when the covers 12 are rotated in the direction 10 of arrow 14. A snap lock mechanism comprising snap lock parts 16a, 16b is provided to keep the openings 10 closed by the covers 12, if desired.

Behind the openings 10 in the top surface 6 of recessed part 4, first optical connectors 18 are arranged at a predetermined position. Each first optical connector 18 comprises an optical fiber end accommodated in a mechanical fixture, together defining a first optical 15 coupling face 20.

A second one of said surfaces defining the recessed part 4, front surface 8, comprises two broad slots 22. As shown in Figure 1, when the covers 12 do not close the openings 10, the covers 12 are situated in the slots 22. At two opposite edges of each slot 22, pairs of oppositely arranged retaining members 24a and 24b are provided, extending over the slot 22 20 over a limited distance. At the bottom of each slot 22, a snap tongue 26 having a stop rib 28 is provided. The snap tongue 26 is formed by providing the bottom wall of the slot 22 with a generally U-shaped groove 30. Ensuring that the slot bottom wall material is elastic, a pressure on the stop rib 28 at right angles to the bottom wall of the slot 22 will make the snap tongue bend such that the stop rib 28 may lie flush with the slot bottom wall plane.

25 It is noted that in the housing 2, provision may be made to accommodate more or less than the two first optical connectors 18. On the one hand, behind each opening 10, more than one first optical connector 18 may be provided. On the other hand, more or less openings 10 (and associated slots 22) may be provided, where behind each opening 10 one or more first optical connecters are situated. For such an alternative arrangement, the dimensions of the 30 openings 10 may be altered and/or the width of the front surface 8 may be altered.

It is further noted that instead of two pairs of retaining members 24a, 24b in the slot 22, in other embodiments of the housing 2 one pair or more than two pairs of retaining members may be provided. The slot 22 and the retaining members 24a, 24b form at least part of a mechanical interface of the housing 2.

35 Figures 2 and 3 show a movable housing 40 having a front side 40a, a back side 40b, a first lateral side 40c, a second lateral side 40d, a top side 40e, and a bottom side 40f.

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The housing 40 has a basic rectangular shape with rounded edges and corners, and at its top side 40e comprises a rectangular protrusion 42 having a front side 42a, a back side 42b, a first lateral side 42c, a second lateral side 42d, and a top side 42e. At the top side 42e, the protrusion 42 is provided with a second optical connector 44 which is arranged in a 5 predetermined position recessed in the protrusion 42. The second optical connector 44 comprises an optical fiber end (not shown) accommodated in a mechanical fixture (not shown), together defining a second optical coupling face (not shown). In another embodiment, the protrusion 42 may be provided with more than one second optical connector 44.

10 At its back side 40b, the housing 40 is provided with two cams 46, 48. Cam 46 is provided with retaining members 24c at opposite ends of the cam 46, and cam 48 is provided with retaining members 24d at opposite ends of the cam 48. The cams 46, 48 and the retaining members 24c, 24d form at least part of the mechanical interface of the housing 40.

The housing 40 may contain a network terminator device. The network terminator 15 device may comprise an electro-optical converter. The housing 40 may also contain at least one optical fiber connected to the second optical connector 44.

As Figure 4 illustrates, the housing 40 can be mounted on the housing 2 using their respective mechanical interfaces, whereby an optical connection is established between a first optical connector 18 of the housing 2, and a second optical connector 44 of the housing 20 40. It is noted that at least one of the first and the second optical connectors may be mounted in its supporting housing with some play to facilitate the coupling of the first and the second connector even when they are not exactly aligned before the coupling.

To enable mounting the housing 40 in the recess 4 of the housing 2, the width of each cam 46 including its retaining members 24c, and the width of each cam 48 including its 25 retaining members 24d, is about equal to, or slightly smaller than the width of a slot 22. Such widths allow the cams 46,48 to slide in a slot 22, with the side of the cams 46,48 facing away from the housing 40 sliding across the bottom of the slot 22. To insert the cams 46,48 into the slot 22, the cam 46 is moved at right angles to the bottom plane of the slot 22 such that each of its retaining members 24c passes between a retaining member 24a and a 30 retaining member 24b at the same edge of the slot 22. This implies that each of the retaining members 24d of the cam 48 passes into the slot 22 below a retaining member 24b, while the side of the cam 48 facing away from the housing 40 contacts the stop rib 28 of the snap tongue 26, and bends the snap tongue 26 away. As a result, the cams 46, 48 come to contact the bottom of the slot 22. From this position, the housing 40 is slid upwards (in the direction 35 indicated by arrow 50), while maintaining contact between the cams 46, 48 and the bottom of the slot 22, whereby the second optical connector 44 contacts, and connects to the first optical connector 18, and the retaining members 24c, 24d come to lie behind the retaining -7- members 24a, 24b respectively. Thus, in this position the housing 40 cannot be moved at right angles to the bottom plane of the slot 22 any more. When a full optical connector connection has been established, the snap tongue 26 returns to its original position, whereby the stop rib 28 prevents, or at least impedes, the housing 40 to move oppositely to the 5 direction indicated by the arrow 50. With a suitable design of the stop rib 28, the snap tongue 26 must be pressed at its free end in order to be able to release the housing 40 from the housing 2, moving the housing 40 in a direction opposite to arrow 50.

In the position of the housing 40 on the housing 2 according to Figure 4, an optimum optical connection is established between the first optical connector 18 and the second optical 10 connector 44 in terms of positioning of the first optical coupling face 20 relative to the second optical coupling face, and in terms of coupling force. This effect can be reached by a proper design and position of the slot 22 and the first optical connector 18 of the housing 2, adapted to the proper design and position of the cams 46, 48 and the second optical connector 44 of the housing 40. During establishment of the optical connection, the protrusion 42 easily 15 enters the opening 10.

For an optimum performance of the optical connection, it is important that the coupling faces of the respective optical connectors abut each other with a predetermined coupling force or contact pressure, that the respective fiber ends are aligned to each other, and that the coupling faces, of the respective optical connectors are clean. The present invention 20 provides for means of cleaning the coupling face of the first optical connector even if this is performed by a non-skilled user, and, in a mechanical inversion, provides for means of cleaning the coupling face of the second optical connector, as will be explained and indicated below.

According to the present invention, and as depicted in Figure 5, a cleaning device 60 25 is provided having a front side 60a, a back side 60b (not visible in the drawing), a first lateral side 60c, a second lateral side 60d (not visible in the drawing), a top side 60e, and a bottom side 60f (not visible in the drawing).

The cleaning device 60 has a basic rectangular shape with rounded edges and corners. The cleaning device 60 has the same mechanical interface to the housing 2 as the 30 housing 40. Accordingly, the cleaning device 60, at the back side 60b thereof, is provided with cams and retaining members identical to the cams 46,48 and retaining members 24c, 24d as explained above with reference to Figures 2 and 3. At the top side 60e, the cleaning device 60 is provided with a protrusion 62 having a cleaning connector 64. The cleaning connector 64 may comprise (part of) a cleaning tool 68 (as schematically indicated by a dashed box), 35 such as a cleaning tape, possibly in a cleaning cassette, or a cleaning stick, as known per se, accommodated in the cleaning device 60. A cleaning action of the cleaning tool 68 may be actuated by a knob 66 which can be pressed or rotated (as schematically indicated by a -8- dashed rotation axis line), for example, where a movement of the knob 66 results, directly or indirectly, in a movement of (part of) the cleaning tool 68.

The cleaning device 60 can be coupled to the housing 2 in the same way as the housing 44, and as illustrated by reference to Figure 4. Thus, the cleaning device 60 and its 5 cleaning tool 68 will assume an accurately predetermined position relative to a first coupling face 20 of a first optical connector 18, and the cleaning tool 68 may exert an accurately determined contact pressure on the first coupling face 20 to reach an optimum cleaning result, even if the cleaning device 60 is not handled by a skilled person, but by an unskilled end-user.

10 Actuating the knob 66 may e.g. move a cleaning tape or a cleaning stick as part of the cleaning tool 68, such as to clean the first optical coupling face 20 of the first optical connector 18. The cleaning device 60 may comprise a power supply, such as a battery, for powering an electric motor to drive the cleaning tool 68, possibly in a preprogrammed manner. In the latter case, the knob 66 may be (coupled to) an electrical switch to turn the 15 cleaning action of the cleaning tool 68 on and off.

As described in detail above, the present invention has the features according to the following clauses.

1. A cleaning device for use in cleaning an optical coupling face of an optical connector assembly, the optical connector assembly comprising a first optical connector 20 having a first optical coupling face, and being connected to a first mechanical interface, and a second optical connector having a second optical coupling face, and being connected to a second mechanical interface, the first mechanical interface and the second mechanical interface being adapted to be coupled to each other in a predetermined way, wherein the cleaning device comprises a cleaning tool configured for cleaning the 25 optical coupling face, and wherein the cleaning device also comprises at least one of the first mechanical interface and the second mechanical interface.

2. The cleaning device according to clause 1, wherein one of the first mechanical interface and the second mechanical interface comprises a slot having slot side walls and a slot bottom, and wherein each slot side wall 30 comprises a first retaining member extending over part of the slot, and wherein the other one of the first mechanical interface and the second mechanical interface comprises a cam having opposite cam side walls and a cam top, and wherein each cam side wall comprises a second retaining member extending from the cam side wall, and wherein the slot is configured to accommodate the cam and the second retaining 35 members, and wherein the first retaining member is provided on the slot side wall at a distance from the slot bottom, and the second retaining member is provided on the cam side wall near the cam top.

-9- 3. The cleaning device according to clause 1 or 2, wherein the cleaning device comprises an actuator for activating the cleaning by the cleaning tool.

4. The cleaning device according to clause 3, wherein the actuator comprises a knob.

5 5. The cleaning device according to any of the preceding clauses, wherein the cleaning tool comprises a cleaning tape.

6. The cleaning device according to any of the preceding clauses, wherein one of the first optical connector and the second optical connector is accommodated at a first wall of a housing, wherein the first mechanical interface is provided 10 at a second wall of the housing, and wherein the plane of the first wall is at right angles to the plane of the second wall.

7. A method of cleaning an optical coupling face of an optical connector assembly, the optical connector assembly comprising a first optical connector having a first optical coupling face, and being connected to a first mechanical interface, and a second 15 optical connector having a second optical coupling face, and being connected to a second mechanical interface, the first mechanical interface and the second mechanical interface being adapted to be coupled to each other in a predetermined way, the method comprising: providing a cleaning device comprising a cleaning tool configured for cleaning the optical coupling face, wherein the cleaning device also comprises at least one of the first 20 mechanical interface and the second mechanical interface; coupling the cleaning device to the optical connector comprising the optical coupling face to be cleaned; and cleaning the optical coupling face with the cleaning tool of the cleaning device.

In summary, an inexperienced or unskilled user may clean the first or the second optical 25 coupling face of the optical connector assembly, using a cleaning device which comprises a cleaning tool configured for cleaning the optical coupling face. The cleaning device also comprises one of the first mechanical interface and the second mechanical interface for easy coupling of the cleaning device to one of the second or first optical connectors, respectively, whereby the cleaning device is positioned accurately relative to the optical connector of which 30 the coupling face is to be cleaned.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. A mechanical inversion of the cleaning device 66 and the housing 2, where the cleaning tool and its actuator is accommodated in the 35 housing 2 instead of in the cleaning device 66, is easily conceivable to clean an optical coupling face of an optical connector 44. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and -10- as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

5 The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the 10 claims or the invention.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

A cleaning device for use in cleaning an optical interface of an optical connector assembly, wherein the optical connector assembly comprises a first optical connector with a first optical interface, and which is connected to a first mechanical interface, and comprises a second optical connector with a second optical interface, which is connected to a second mechanical interface, the first and the second mechanical interface being arranged to be coupled to each other in a predetermined manner, the cleaning device comprising a cleaning tool configured for cleaning of the optical interface, and wherein the cleaning device also comprises at least one of the first mechanical interface and the second mechanical interface.

The cleaning device according to claim 1, wherein one of the first mechanical interface and the second mechanical interface comprises a slot with slot side walls and a slot bottom, and wherein each slot side wall comprises a first retaining member extending over a portion of the slot, and wherein the other of the first mechanical interface and the second mechanical interface comprises a cam with opposite cam side walls and a cam top, and wherein each cam side wall comprises a second retaining member extending from the cam side wall, and wherein the slot is configured around the cam and receiving the second retaining members, and wherein the first retaining member is provided on the slot side wall spaced from the slot bottom, and the second retaining member is provided on the ridge side wall near the top ridge.

The cleaning device according to claim 1 or 2, wherein the cleaning device comprises an actuator for activating the cleaning by the cleaning tool. 30

The cleaning device of claim 3, wherein the actuator comprises a button.

The cleaning device according to any of the preceding claims, wherein the cleaning tool comprises a cleaning belt. 35

The cleaning device according to any of the preceding claims, wherein one of the first optical connector and the second optical connector is included at a first 12 wall of a housing, the first mechanical interface being provided at a second wall of the housing and wherein the plane of the first wall is perpendicular to the plane of the second wall.

A method for cleaning an optical interface of an optical connector assembly, wherein the optical connector assembly comprises a first optical connector with a first optical interface, and which is connected to a first mechanical interface, and a second optical connector comprises a second optical interface, which is connected to a second mechanical interface, wherein the first and the second mechanical interface are adapted to be coupled to each other in a predetermined manner, which method comprises: providing a cleaning device comprising a cleaning tool that is configured for cleaning the optical interface, wherein the cleaning device also comprises at least one of the first mechanical interface and the second mechanical interface; coupling the cleaning device to the optical connector comprising the optical interface to be cleaned; and cleaning the optical interface with the cleaning tool of the cleaning device. 20