DE4219901A1 - Optical fiber end sleeve - Google Patents

Abstract

A terminating sleeve (1) for optical waveguides, having disposed at its distal end (3) an optical waveguide insertion opening leading into an optical waveguide receiving channel (8) disposed in the longitudinal direction in the terminating sleeve (1), the terminating sleeve (1) being formed integrally with a coupling means (6) disposed at the proximal end and serving for coupling and uncoupling light, the optical waveguide receiving channel (8) extending from the optical waveguide insertion opening up to the coupling means (6) and the terminating sleeve (1) inclusive of the coupling means (6) being made from an optically transparent material. The optical coupling means (6) has a convexly curved surface (61) on the side directed towards the terminating end of the terminating sleeve (1). This provides the optical effect of a convex lens by a light beam (15). However, it is also possible to provide other optical effects by a different design of the optical coupling means (6) directed towards the terminating end. For example, thi surface may be a concavely curved surface, e.g. when the optical area of a complementary connector has a larger diameter than the optical coupling means (6) e.g. in case of an optical coupling with a light-emitting diode or a phototransistor in the complementary connector. The surface of the optical coupling means (6) located at the terminating end of terminating sleeve (1), however, may also be a planar surface oriented either perpendicularly to the OWG axis or at an angle thereto. An inclined planar surface may be used when reflections of the light coming from the OWG are to be avoided or at least reduced on the planar surface.

Description

The invention relates to a for fiber optic Connector usable fiber optic termination sleeve and an optical fiber Connector for coupling optical fibers with each other and with optical fibers optical or optoelectronic components.

The term "optical fiber" is used below abbreviated with "LWL".

In the same way as for electrical conductors there is also a need for LWL for inexpensive, functionally reliable connectors with which the fiber can be coupled with each other by the ends of which are to be coupled close together be held appropriately, or with which fiber optics with light emitting or receiving optical or optoelectronic components are coupled can optically send the ends of the fiber optic the or receiving surfaces more optoelectronic Components are kept closely opposite.

To the light transmission losses in connectors Keeping the minimum possible for LWL must be possible Care must be taken that the LWL to be coupled to each other or to the optoelectronic construction elements are centered as precisely as possible and the surfaces to be optically coupled as parallel as possible and be kept close to each other. Because of the  Small diameter of the usual fiber optic is a very high accuracy of mutual radial posi tioning to couple with the connector the fiber optic required. When using conventional Technology for fiber optic connectors proves it in particular for connectors with several FO as almost impossible to get this exact radial and ensure axial positioning.

To overcome this problem are the older ones German patent applications P 41 06 594.8 and P 41 41 009.2 termination devices for an optical fiber have been proposed, each one - here "Ab closing sleeve "called - sleeve-like end element have ment with a through opening is provided, in one end a fiber optic piece is firmly arranged and in the other end End area of the fiber to be closed essentially can be inserted up to the fiber optic piece. The Offenba content of the older applications mentioned by reference to the present application taken.

Both the FO piece and preferably exist the optical fiber to be connected is highly transparent plastic, for example acrylic glass. For the End sleeves are usually optically intrans Parent plastic materials provided. Both Items of the aforementioned older ones Patent applications are therefore an assembly process required, in which the optically non-transparent End sleeve with an optical waveguide piece which is the optical interface both to the FO to be connected and to the counterpart piece of the connector forms. Especially in With regard to the mass production of such connectors there is a need to manufacture  and assembly of such connectors further simplify.

It is an object of the present invention therefore, an end sleeve for an optical fiber and one Fiber optic connectors in proposal to bring that towards the objects of the older ones mentioned Patent applications especially with regard to easier manufacture, assembly and better over wearing properties are advantageous.

This object is achieved for one End sleeve according to the preamble of the patent Proverb 1 by the in its label part specified characteristics. Subclaims 2 to 10 are advantageous developments of the closure sleeve see. Claim 11 is a fiber optic Connector with an end sleeve after one of claims 1 to 10.

The optical fiber end sleeve according to the invention and the fiber optic connectors equipped with it will be available mainly for bidirectional light transmission used.

The invention and developments of the invention, further task aspects and further advantage aspects are now related to an execution form of the invention with reference to the drawing he purifies:

Fig. 1 shows a plan view of a first embodiment of an end sleeve according to the invention.

Fig. 2 shows a longitudinal section through the end sleeve shown in Fig. 1 along the section line II.

Fig. 3 shows a longitudinal section through the end sleeve shown in Fig. 1 ent along the section line II in Fig. 1, the section plane being rotated with respect to those of Fig. 2 by about 90 °.

Fig. 4 shows a plan view of the end of the closure sleeve shown in Fig. 1.

Fig. 5 shows a cross section through the end sleeve shown in Fig. 2 along the section line II-II.

Fig. 6 shows a cross section through the end sleeve shown in Fig. 2 along the section line III-III.

Fig. 7 shows a longitudinal section through two end sleeves placed opposite at their respective end.

Fig. 8 shows a second embodiment of an end sleeve according to the invention in longitudinal sectional view.

Fig. 9 shows a third embodiment of an end sleeve according to the invention in longitudinal sectional view.

Fig. 10 shows a longitudinal sectional view of a connector assembly with two plug-in connectors, one of which with two end sleeves of the type shown in Fig. 9 is hen.

FIG. 11 shows a longitudinal side view of the connector arrangement according to FIG. 9.

Fig. 1 shows a plan view of a first exporting approximate shape of a terminating sleeve 1 according to the invention prior to their addition to a closing element by mounting a lock plate (not shown). The end sleeve 1 has essentially three sections, namely at its left in Fig. 1 connector side end, hereinafter called the end, a hollow cylinder part 2 , at its right in Fig. 1, fiber optic insertion side end a Arretierbügelaufnah meteil 3 and in between a middle part 4 .

The structure of the locking bracket receiving part 3 is already explained in the prior patent applications P 41 06 594.8 mentioned above and in particular P 41 41 009.2. Therefore, reference is made here to this extent.

Fig. 2 shows a longitudinal section through the in Fig. Terminating sleeve 1 shown 1 taken along section line II. The direction of this section is indicated in Fig. 5 with Ia-Ia. The sleeve body of the end sleeve 1 is made of a transparent material of optical quality, for example poly carbonate or polymethyl methacrylate (PMMA), preferably also made of the same material as the fiber when using fiber optic material made of plastic. At its terminating end, the terminating sleeve 1 has a coupling surface 5 of an optical coupling device 6 , which in the first embodiment has a convexly curved optical surface 61 . In this embodiment of the end sleeve 1 , an annular groove 7 is arranged in the optical coupling surface 5 , which surrounds the convexly curved surface 61 , so that a circumferential rib 71 is formed which protrudes in the axial direction beyond the convexly curved surface 61 . The circumferential rib 71 thus protects the convexly curved surface 61 and it can also have a positioning function.

In order to facilitate the insertion of the optical fiber from the fiber optic introducer of the terminating sleeve 1 into an essentially longitudinally arranged in the terminating sleeve 1 , the optical fiber receiving channel 8 , the inner surface of the optical fiber receiving channel 8 is in a preferred embodiment with a positioning device in Form of an insertion centering device 9 is provided. The insertion centering device 9 consists, in a particularly preferred embodiment, of three guide ribs 10 a, 10 b, 10 c, the radial spacing of which is evenly spaced apart from one another in the direction of the circumference of the optical fiber receiving channel 8 , in the longitudinal direction parallel in the optical fiber receiving channel 8 longitudinal axis of the fiber-receiving channel 8 to the terminal end of the terminating sleeve 1 decreases toward, so that increases upon insertion of an optical fiber in the optical fiber on acquisition channel 8 the lateral play of the inserted optical fiber with progressive insertion process, until the inserted optical fiber substantially radially centered on the LWL introducer white send page 62 of the optical coupling device 6 on. A contact gel (not shown) with preferably the same refractive index as the LWL material has is preferably arranged between the inserted optical fiber and the side 62 of the optical coupling device 6 pointing toward the optical fiber introducer. The contact gel ensures reliable optical coupling between the optical fiber and the optical coupling device 6 . A contact gel can flow backwards into the spaces 13 remaining between the ribs 10 .

Fig. 3 shows a longitudinal section through the embodiment illustrated in Fig. 1 terminating sleeve 1 along the line II Verbin dung, wherein the cutting plane with respect to that of FIG. Rotated 90 # 2. In this sectional representation 10 has two ribs 10 are a total of three arranged guide fins 10 b visible. The direction of this section is identified in Fig. 5 with Ib-Ib.

Fig. 4 shows a plan view of the terminal end of the firing sleeve 1 shown in Fig. 1 with the convex surface 61 of the annular groove 7 and the circumferential rib 71st

Fig. 5 shows a cross section through the end sleeve 1 shown in Fig. 2 along the section line II-II. The three guide ribs 10 a, 10 b, 10 c are evenly spaced from one another on the wall of the fiber optic receiving channel 8 . The stages 11 a, 11 b, 11 c and 12 a, 12 b, 12 c bring about a smaller and smaller scope for the optical fiber to be introduced towards the end of the end sleeve 1 .

Fig. 6 shows a cross section through the end sleeve 1 shown in Fig. 2 along the section line III-III. Due to the ribs 10 a, 10 b, 10 c remaining between the guide cavities 13 a, 13 b, 13 c, excess contact gel (not shown) can flow off in the direction of the fiber optic insertion of the end sleeve 1 .

Fig. 7 shows a longitudinal section through two opposite end sleeves 1 a, 1 b at their respective end. The between the end sleeves 1 a, 1 b in the form of the adjacent ring grooves 7 a, 7 b forming air space that z. B. the emerging from the end sleeve 1 a light beam 15 in a large angle area in the end sleeve 1 b and the optical fiber 16 b arranged in it is coupled. The circumferential ribs 71 lying one against the other protect the convexly curved surfaces 6 a, 6 b from mechanical damage due to the frictional action of the opposing surfaces.

The previously described first embodiment of an end sleeve according to the invention is characterized in that the optical coupling device 6 , the adjoining positioning device with the guide ribs 10 a, 10 b, 10 c and the rest of the end sleeve 1 are combined to form an integral component, the consists of transparent material in optical quality. In most cases, the best possible permeability of the light waves through the optical coupling device 6 is desired. In these cases, the component is made of highly transparent material. For example, to achieve filter effect, the transparent material can also be colored.

In the above-described first embodiment, the optical coupling device 6 has a convexly curved surface 61 on the side that is white at the end of the end sleeve 1 . The optical effect of a convex lens is thus achieved, as indicated by a light beam 15 in FIG. 7.

However, other optical effects can also be achieved by a different design of the optical coupling device 6 pointing towards the end. For example, this surface can be a concavely curved surface, for example if the optical surface of a mating connector has a larger diameter than the optical coupling device 6 , for example in the case of optical coupling with a light-emitting diode or a phototransistor in the mating connector.

The surface of the optical coupling device 6 located at the end of the end sleeve 1 can, however, also be a flat surface, which is either aligned perpendicular to the fiber optic axis or at an angle to it. An inclined plane surface can be used if reflections of the light coming from the optical fiber on the plane surface are to be avoided or at least reduced.

A second embodiment of an end sleeve according to the invention, the optical coupling device of which is provided on both sides with a plane surface perpendicular to the optical fiber longitudinal axis, is shown in FIG. 8. Otherwise, this embodiment corresponds to the first embodiment shown in FIGS. 1 to 7.

In the two preceding embodiments, the entire one-piece end sleeve is fixed with respect to the optical function of the end of the end sleeve facing surface of the optical coupling device 6 . If you need end sleeves with different optical functions of your optical coupling device for different purposes, you need a corresponding number of different end sleeves. In addition, the entire end sleeve must consist of transparent or even highly transparent material of high optical quality.

An improvement in this respect, bringing a third embodiment of a terminating sleeve 91 OF INVENTION to the invention shown in Fig. 9. This end sleeve is in two parts and has a sleeve body 91 and a part 92 fastened thereon by means of a snap connection. The component 92 contains in one piece an optical coupling device 6 and a positioning device 93 , which adjoins the optical coupling device 6 towards the optical coupling device 6, for radially centering an inserted optical fiber. The interior of the positioning device 93 represents a continuation of the fiber optic receiving channel 8. The positioning device 93 can either be provided with guide ribs (not shown in FIG. 9) or the guide ribs 10 a, 10 b, 10 c of the first two embodiments are the same or are similar. Or the inner wall of the Positionierein device 93 can even effect the radial centering. In this case, the inner diameter of the positioning device 93 can decrease towards the optical coupling device 6 , so that an optical fiber that is introduced is centered more and more radially with increasing distance from the optical coupling device 6 .

The positioning device 93 can, however, also be used for the axial positioning of the optical fiber, in that the optical fiber is fixed axially immovably in the positioning device 93 .

In the embodiment shown in FIG. 9, locking takes place between the component 92 and the sleeve body 91 with the aid of locking projections 94 projecting radially outward from the component 92 and complementary locking recesses 95 in the sleeve body 91 . In the case of the entire wall of the sleeve body 91 passing through recesses 95 Rastaus more preferably Rastvor cracks 94 and locking recesses 95 distributed around the circumference of the component 92 and sleeve body 91st Does not extend the locking recess 95 through the entire wall of the sleeve body 91 through it can be formed as a circumferential locking groove around the inner circumference of the sleeve body 91 and provide the component 92 with a corresponding detent flange around its outer circumference. This enables a particularly simple assembly of the component 92 within the sleeve body 91 , because this assembly is possible in any relative rotational position between the component 92 and the sleeve body 91 .

In the embodiment shown in FIG. 9, only the component 92 with the positioning device 93 and the optical coupling device 6 , which in the embodiment shown in FIG. 9 has a concavely curved surface, need to be made of transparent material of optical quality. The sleeve body 91 can be made of any other material, the optical properties th are irrelevant.

In the embodiment according to FIG. 9, different components 92 with different coupling surfaces of the optical coupling device 6 and / or from different transparent material can be kept available, whereas only a single type of sleeve body 91 is required. The desired variant of the component 92 is inserted into the sleeve body 91 .

Of course, other types of connection between sleeve body 91 and component 92 are possible than the snap connection shown in FIG. 9. Examples are an adhesive connection, a welded connection, a friction adhesion connection and a screw connection.

FIGS. 10 and 11 show in Längsquerschnittdar position or in longitudinal side view of a fiber optic connector assembly Ver which come in the two ferrules in Fig. 9 type shown used. Apart from differences in connection with the end sleeves, the connector arrangement shown in FIG. 10 corresponds to that of the fiber optic connector arrangement which is shown in FIG. 1 of the already mentioned older patent application P 41 41 009.2 Darge. With regard to the detailed description and explanation, reference is therefore made to this earlier patent application, the disclosure content of which is made the subject of the disclosure of the present application by reference to this earlier application. In the following brief description of the connector arrangement shown in FIG. 10, the reference numerals used in FIG. 1 are used for easier comparison with the older patent application, but each increased by 100.

The fiber optic connector arrangement shown in FIG. 10 in longitudinal section has a plug connector 111 , with which two fiber optic cables 113 are terminated, and a mating connector 115 , in which a photo transistor 117 and a light-emitting diode (LED) 119 are accommodated. The plug connector 111 has a connector housing 121 , which is crossed by two adjacent passage channels 123 . A terminating sleeve 1 according to the invention is located in the connection-side end of each passage 123 opposite the counterpart connector 115 . The end of one of the two optical fibers 113 is inserted into their optical fiber receiving channel 8 . At one end of each end sleeve 1 remote from the mating connector 115, there is one end of a helical spring 131 which is supported at the other end on a radial shoulder 113 in the respective passage 123 .

In a fiber optic insertion-side opening of the connector 111 at its end opposite the connector end ent a strain relief plug 135 is inserted, which also has the function of a sealing plug. Through the strain relief plug 135 pull two fiber optic channels 137 through which the optical fibers 113 are passed. The strain relief plug 135 has radial outer beads 139 protruding from its outer circumference and radial inner beads 141 projecting into the fiber optic channels 137 . The outer beads 139 and the inner beads 141 seal the FO 113 . At its end facing the connector side, the strain relief plug 135 is provided with two cylindrical connecting pieces 143 , the interior spaces of which form a continuation of the fiber optic channels 137 .

The LWL 113 have an optical waveguide core, which is surrounded by a cladding, which is provided to improve the light-guiding properties of the LWL. The cladding is surrounded by a protective plastic jacket. In the embodiment of an optical fiber connector arrangement shown in FIG. 10 with two-part end sleeves according to FIG. 9, the plastic sheath together with the optical fiber surrounded by it extends to the fiber optic-leading side 62 of the optical coupling device 6 of the end sleeve 1 .

In the area between the coil spring 131 and the strain relief plug 135 , a crimp sleeve 145 is provided on each FO 113 . Each crimp sleeve 145 has a first crimping zone 147 crimped around the associated connection piece 143 of the strain relief plug 135 and a second crimping zone 149 crimped around the adjacent region of the optical fiber 113 . At one end facing the coil spring 131 , each crimp sleeve 145 is provided with a cylindrical locking region 151 , from the diametrically opposite sides of which a locking lobe 153 to the second crimping zone 149 is inclined. The locking lances 153 interact with a correspondingly positioned, radial locking shoulder 155 in the associated passage 123 .

Particularly when the connector arrangement and the FO 113 are to be accommodated in an environment with mechanical shocks, vibrations, etc., for example in motor vehicles, the light-conducting cores of the FO 113 are also made of plastic, preferably acrylic glass.

In order to hold the optical fiber 113 securely in the terminating sleeve 1 after it has been fully inserted into the optical fiber receiving channel 8 , an essentially U-shaped locking bracket is provided, the legs of which are formed by two locking forks, namely a locking fork 161 on the connector side and a locking fork on the insertion side 163 . The two locking forks 161 and 163 each extend vertically from a web of the locking bracket parallel to the longitudinal axis of the LWL 113 . Each locking fork 161 , 163 has a clamping slot for clamping the locking fork 161 or 163 on the plastic jacket of the FO 113 . The two Arre animal forks 161 and 163 each sit in a steckver connection-side fork receiving opening 165 and in a fiber optic insertion-side fork receiving opening 167 .

In the manner explained in more detail in the already mentioned P 41 41 009.2, the helical spring 131 can be used to ensure that both the optical fiber 113 is pressed against the opposite side 62 of the optical coupling device 6 and the coupling surface 5 of the terminating sleeve 1 optimally against this associated optoelectronic or optical component is pressed.

In the exemplary embodiment considered in FIG. 10, the optical fibers 113 are each optically coupled to an optoelectronic component via the associated end sleeves 1 . The connector 111 can also cooperate with a mating connector, with which fiber optic cable is also completed. In this case, the coupling surfaces 5 of the terminating sleeves of the connector 111 are optically coupled in the manner shown in FIG. 7 with the coupling surfaces of terminating sleeves 1 of the mating connector. A basic example of this type, although with different types of end sleeves, is shown in Fig. 1 of the aforementioned P 41 06 594.

When in Fig. Side view of a fiber optic connector assembly 11 shown in FIG. 10 are the connector 111 and the mating connector fixed to 115 in a known manner to a housing wall 201 having therein a through hole 202 for the housing of the mating connector 115. Legs 203 of the mating connector 115 , which are preferably formed by legs of optoelectronic components housed in the mating connector 115 , are connected to a circuit board 204 . The connector 111 has a cover cap 205 on the optical fiber insertion side, which is connected to the housing of the connector 111 by means of a bayonet catch.

Claims (11)

1. For fiber optic (FO) connector used bare fiber end sleeve ( 1 ), which has a fiber optic one leading and an opposite from the final end, with an axially extending fiber optic receiving channel ( 8 ), the fiber optic one leading is open, characterized

• - That the fiber optic receiving channel ( 8 ) is closed in the region of the end by an optical coupling device ( 6 ), which is used for light transmission from an optical fiber in the fiber optic receiving channel ( 8 ) end through the end of the end sleeve ( 1 ),
• - That one of the optical coupling device ( 6 ) adjacent positioning device ( 10 a, 10 b, 10 c; 93 ) for positioning the fiber optic end within the fiber optic receiving channel ( 8 ) is provided, and
• - That the optical coupling device ( 6 ) and the positioning device ( 10 a, 10 b, 10 c; 93 ) are formed as a one-piece component made of transparent material of optical quality.

2. Optical fiber end sleeve, according to claim 1, characterized in that the end sleeve ( 1 ) including the one-piece component is formed in one piece from the transparent material. 3. FO terminating sleeve according to claim 1, characterized in that the one-piece component ( 92 ) from the rest of the terminating sleeve ( 1 ) is separate and mountable component. 4. FO terminating sleeve according to claim 3, characterized in that only the one-piece component ( 92 ) consists of transparent material of optical quality. 5. Optical fiber end sleeve according to claim 3 or 4, characterized in that the one-piece component ( 92 ) on the rest of the end sleeve ( 1 ) by means of snap connection ( 94 , 95 ) can be fastened. 6. FO terminating sleeve according to one of claims 1 to 5, characterized in that the coupling surface ( 5 ) facing the end of the optical coupling device ( 6 ) is formed by a flat surface ( Fig. 8). 7. FO terminating sleeve according to one of claims 1 to 5, characterized in that the coupling surface ( 5 ) of the optical coupling device ( 6 ) facing the end has a curved surface, in particular a concave or a convex surface ( 61 ). 8. FO terminating sleeve according to claim 7, characterized in that the coupling surface ( 5 ) can be surrounded by a projecting over it annular shoulder ( 71 ). 9. FO terminating sleeve according to one of claims 1 to 8, characterized in that the optical coupling device ( 6 ) is designed as a wavelength filter, for example by coloring its transparent material. 10. optical fiber end sleeve according to one of claims 1 to 9, characterized in that as a positioning device for radially centering the optical fiber in the optical fiber receiving channel ( 8 ) a plurality of circumferentially equally spaced, in the longitudinal direction parallel guide elements ( 10 a, 10 b, 10 c) are seen before, the clear distance of which narrows towards the optical coupling device ( 6 ). 11. FO connector ( 111 ) with a connector housing for receiving at least one FO ( 113 ), which can be coupled with an optical fiber, an optical component or an optoelectronic component in a mating connector ( 115 ), with at least one in the longitudinal direction of the Passage channel ( 123 ) for a fiber optic cable ( 113 ), characterized in that at least one end sleeve ( 1 ) according to one or more of claims 1 to 11 is arranged in the plug-in end region of the connector housing.