Patent Application
20090208174
The invention relates to an apparatus for positioning optical fibers, by means of which, for example, optical fibers can be aligned with respect to one another before a splicing process.
At least two optical fibers are connected by means of a splicing apparatus, in which the ends of the two optical fibers are heated, and are fused to one another. The heating process is generally carried out by means of a corona discharge between two electrode points. The splicing attenuation at the junction point between the two optical fibers is dependent inter alia on precise alignment of the two optical fibers with respect to one another, before the actual heating process. In order to align the ends of the two optical fibers, they are inserted in two mutually opposite optical fiber guides. This results in the two optical fibers to be spliced being aligned roughly with respect to one another.
Fine alignment of the two fibers is carried out, for example, by piezo-components which are arranged under the two optical fiber guides. By application of a voltage to the piezoelectric components, the optical fiber guides, which are connected to them, can be displaced with respect to one another. In this case, temperature fluctuations can also cause the two optical fiber guides to be displaced with respect to one another. Since only a slight displacement of the optical fibers can be achieved by means of the piezo-components, the position changes of the optical fiber guides caused by temperature fluctuations must be compensated for.
If the piezo-component is intended to compensate for optical fiber guide displacements caused by temperature fluctuations, a piezo-component must be used for this purpose which allows large movement changes to be achieved. Piezo-components such as these are, however, very expensive. Further high costs are also incurred by drive circuits for supplying the piezo-components with a high voltage, and by means of complex DC/DC converters.
The object of the present invention is to provide an apparatus for positioning optical fibers, in which the optical fibers can be aligned with respect to one another in a simple and reliable manner.
The object is achieved by an apparatus for positioning optical fibers comprising a supporting plate, comprising a first optical fiber guide, into which at least a first optical fiber can be inserted, comprising a second optical fiber guide into which at least a second optical fiber can be inserted, and comprising a first movement stepping-down apparatus to displace the first optical fiber in a lateral direction transversely with respect to a longitudinal direction of the first optical fiber, which first movement stepping-down apparatus has a first end and a second end. The first optical fiber guide is arranged on an area of the first movement stepping-down apparatus which is closely adjacent to the first end of the first movement stepping-down apparatus. The apparatus furthermore comprises a first drive device which is coupled to the supporting plate and which can cause a change in the position at the second end of the first movement stepping-down apparatus. The first movement stepping-down apparatus is configured to convert the movement change caused by the first drive device at the second end of the first movement stepping-down apparatus to a smaller movement change on the area of the first movement stepping-down apparatus which is closely adjacent to the first end of the first movement stepping-down apparatus.
In an embodiment of the apparatus, a second movement stepping-down apparatus is provided to displace the second optical fiber in a lateral direction transversely with respect to a longitudinal direction of the second optical fiber, which second movement stepping-down apparatus has a first end and a second end. The second optical fiber guide is arranged on an area of the second movement stepping-down apparatus which is closely adjacent to the first end of the second movement stepping-down apparatus. Furthermore, the apparatus has a second drive device, which is coupled to the supporting plate and which can cause a change in the position at the second end of the second movement stepping-down apparatus. The second movement stepping-down apparatus is configured to convert the movement change caused by the second drive device at the second end of the second movement stepping-down apparatus to a smaller movement change on the area of the second movement stepping-down apparatus which is closely adjacent to the first end of the second movement stepping-down apparatus.
Another embodiment of the apparatus comprises a first displacement apparatus to displace the first optical fiber in the longitudinal direction of the first optical fiber, on which first displacement apparatus the first optical fiber guide is arranged, and a third drive device, which is coupled to the supporting plate and causes displacement of the first optical fiber in the longitudinal direction of the first optical fiber by means of a force acting on the first displacement apparatus. The first displacement apparatus is configured such that it produces a restoring force opposing the force caused by the third drive device. The first displacement apparatus is coupled to that area of the first movement stepping-down apparatus which is closely adjacent to the first end of the first movement stepping-down apparatus.
According to another embodiment, the apparatus has a second displacement apparatus to displace the second optical fiber in the longitudinal direction of the second optical fiber, on which second displacement apparatus the second optical fiber guide is arranged. Furthermore, a fourth drive device is provided, which is coupled to the supporting plate and causes displacement of the second optical fiber in the longitudinal direction of the second optical fiber by means of a force acting on the second displacement apparatus. The second displacement apparatus is configured such that it produces a restoring force opposing the force caused by the fourth drive device. The second displacement apparatus is coupled to that area of the second movement stepping-down apparatus which is closely adjacent to the first end of the second movement stepping-down apparatus.
Another embodiment of the apparatus provides a first supporting apparatus on which the first optical fiber guide is arranged. The first supporting apparatus is coupled to the first displacement apparatus. Furthermore, a second supporting apparatus is provided, on which the second optical fiber guide is arranged. The second supporting apparatus is coupled to the second displacement apparatus.
In an embodiment of the apparatus, the first movement stepping-down apparatus has a lever arm with a first end and a second end. The first end of the lever arm of the first movement stepping-down apparatus is connected to the supporting plate. The second end of the lever arm of the first movement stepping-down apparatus can be moved by the first drive device. The second movement stepping-down apparatus has a lever arm with a first end and a second end. The first end of the lever arm of the second movement stepping-down apparatus is connected to the supporting plate. The second end of the lever arm of the second movement stepping-down apparatus can be moved by the second drive device.
A further embodiment of the apparatus has a further first movement stepping-down apparatus to displace the first optical fiber in the lateral direction for the first optical fiber, which further first movement stepping-down apparatus has a first end and a second end. The further first movement stepping-down apparatus is configured to convert a movement change caused at the second end of the further first movement stepping-down apparatus to a smaller movement change on the area of the further first movement stepping-down apparatus which is closely adjacent to the first end of the further first movement stepping-down apparatus. The apparatus also has a further first displacement apparatus to displace the first optical fiber in the longitudinal direction of the first optical fiber as a consequence of a force caused by the third drive device. The further first displacement apparatus is configured such that it produces a restoring force opposing the force caused by the third drive device. The further first displacement apparatus is coupled to that area of the further first movement stepping-down apparatus which is closely adjacent to the first end of the further first movement stepping-down apparatus. The first supporting apparatus is arranged on the further first displacement apparatus.
Furthermore, in the case of the apparatus according to the invention, a further second movement stepping-down apparatus can be provided for displacing the second optical fiber in the lateral direction for the second optical fiber, which further second movement stepping-down apparatus has a first end and a second end. The further second movement stepping-down apparatus is configured to convert a movement change caused at the second end of the further second movement stepping-down apparatus to a smaller movement change on the area of the further second movement stepping-down apparatus which is closely adjacent to the first end of the further second movement stepping-down apparatus. Furthermore, a further second displacement apparatus is provided for displacing the second optical fiber in the longitudinal direction of the second optical fiber as a consequence of a force caused by the fourth drive device. The further second displacement apparatus is configured such that it produces a restoring force opposing the force caused by the fourth drive device. The further second displacement apparatus is coupled to that area of the further second movement stepping-down apparatus which is closely adjacent to the first end of the further second movement stepping-down apparatus. The supporting apparatus on which the second optical fiber guide is arranged on the further second displacement apparatus.
In a further embodiment of the apparatus, the first supporting apparatus is connected to the first displacement apparatus via a bending hinge. The first supporting apparatus is connected to the further first displacement apparatus via a bending hinge. The second supporting apparatus is connected to the second displacement apparatus via a bending hinge. The second supporting apparatus is connected to the further second displacement apparatus via a bending hinge.
In another embodiment of the apparatus, the further first movement stepping-down apparatus has a lever arm with a first end and a second end. The first end of the lever arm of the further first movement stepping-down apparatus is connected to the supporting plate. The second end of the lever arm of the further first movement stepping-down apparatus is moveable. The further second movement stepping-down apparatus has a lever arm with a first end and a second end. The first end of the lever arm of the further second movement stepping-down apparatus is connected to the supporting plate. The second end of the lever arm of the second movement stepping-down apparatus is moveable.
According to an embodiment of the apparatus, the first drive device can cause a movement change at the second end of the lever arm of the further first movement stepping-down apparatus. The second drive device can cause a movement change at the second end of the lever arm of the further second movement stepping-down apparatus.
A further embodiment provides for the lever arms to be in the form of part of the supporting plate and are composed of the same material as the supporting plate.
In one preferred embodiment, a respective area of the lever arms, which area is remote from their respective first end, is stamped out of the supporting plate.
According to a further preferred embodiment of the apparatus according to the invention, the lever arms are connected at their respective first ends to the supporting plate via a respective web.
In another embodiment of the apparatus, the first and the second drive device each have a lifting apparatus to deflect the respective second ends of the lever arms from a plane which is formed by the supporting plate, and have a respective motor to drive the respective lifting apparatus.
According to another embodiment, the respective lifting apparatuses of the first and second drive devices each have an eccentric which can rotate and is moved by a respective one of the motors of the first and second drive devices.
In a further embodiment of the apparatus, the third and the fourth drive device to displace the displacement apparatuses have a respective motor and an eccentric which can rotate. The respective motor of the third and the fourth drive device produces a rotary movement of the respective eccentric of the third and the fourth drive device. The rotary movement of the respective eccentric of the third and the fourth drive device produces a displacement of the displacement apparatuses in the longitudinal direction of the first and the second optical fiber.
According to one preferred embodiment, the displacement apparatuses each have a spring plate.
In one preferred embodiment, the supporting plate is in the form of a printed circuit board on which electrical lines are routed. By way of example, the printed circuit board may be in the form of a glass-fiber-reinforced printed circuit board. It is also possible for the supporting plate to be formed from a plastic or for it to be in the form of a metallic plate. In this case, a printed circuit board, on which electrical lines are routed, is preferably arranged under the supporting plate.
The use of a printed circuit board has the advantage that components such as electrode holders, illumination units to illuminate the optical fiber guides and the splicing area or else monitoring units, such as image processing units, can be arranged by an automatic placement device on the printed circuit board. Furthermore, supply lines to supply components such as these can likewise be integrated on the printed circuit board. There is therefore no need for complex wiring.
A further embodiment of an apparatus for positioning optical fibers, in which the optical fibers can be moved with respect to one another only in a longitudinal direction, comprises a supporting plate, a first optical fiber guide, into which at least a first optical fiber can be inserted, a second optical fiber guide, into which at least a second optical fiber can be inserted, a first displacement apparatus to displace the first optical fiber in a longitudinal direction of the first optical fiber, on which first displacement apparatus the first optical fiber guide is arranged, and a first drive device, which is coupled to the supporting plate and displaces the first optical fiber in the longitudinal direction of the first optical fiber by a force acting on the first displacement apparatus. The first displacement apparatus is configured such that it produces a restoring force opposing the force caused by the first drive device.
In an embodiment of the apparatus, a second displacement apparatus is provided for displacing the second optical fiber in a longitudinal direction of the second optical fiber, on which second displacement apparatus the second optical fiber guide is arranged. Furthermore, a second drive device is provided, which is coupled to the supporting plate and displaces the second optical fiber in the longitudinal direction of the second optical fiber by a force acting on the second displacement apparatus. The second displacement apparatus is configured such that it produces a restoring force opposing the force caused by the second drive device.
The optical fibers 1 and 2 are each inserted in a groove in an optical fiber guide 20a and an optical fiber guide 20b. The optical fiber guides 20a and 20b are respectively arranged in a supporting apparatus 21a and a supporting apparatus 21b. The supporting apparatus 21a is mounted on a displacement apparatus 8a to displace the optical fiber 1 in a longitudinal direction Z of the optical fiber. The displacement apparatus 8a to displace the optical fiber 1 in the longitudinal direction Z of the optical fiber is, for example, in the form of a spring plate 80a. The spring plate 80a is bent by a lever 51a in the direction Z as shown in order to displace the optical fiber guide 20a, to be precise the optical fiber 1, in its longitudinal direction in the direction of the end of the optical fiber 2. The spring plate 80a is bent by means of a drive device A3. There is a cutout, in which an eccentric 50a engages, at one end of the lever 51a. The lever 51a is displaced in the Z direction by a rotary movement of the eccentric, and forces the spring plate 80a with the optical fiber guide 20a in the direction of the optical fiber 2.
The optical fiber guide 20b of the optical fiber 2 is likewise arranged in a supporting apparatus 21b. The supporting apparatus 21b is mounted on a displacement apparatus 8b to displace the optical fiber 2 in its longitudinal direction Z in the direction of the optical fiber 1. The displacement apparatus 8b to displace the optical fiber 2 in its longitudinal direction is preferably in the form of a spring plate 80b. The spring plate 80b can be bent by the action of a force by means of a drive device A4 via a lever 51b such that the optical fiber guide 20b, to be precise the optical fiber 2, is moved in the direction of the optical fiber 1. The lever 51b is displaced by rotation of an eccentric 50b, which engages in a cutout at the end of the lever 51b. The optical fibers can thus be displaced in the negative Z direction by bending the two spring plates 80a and 80b, such that their ends can be brought into contact with one another, for a splicing process.
In order to allow the two ends of the optical fibers 1 and 2 to be aligned precisely with respect to one another, it must also be possible to displace the optical fibers in a lateral direction, transversely with respect to their respective longitudinal direction. In order to displace the optical fiber 1, the spring plate 80a and therefore the optical fiber guide 20a are arranged on a movement stepping-down apparatus 6a to displace the optical fiber 1 in its lateral direction. The movement stepping-down apparatus 6a comprises a lever arm 60a which can be bent about a bending axis 70a. The lever arm 60a is stamped out of the printed circuit board 10 as part of the printed circuit board, and is connected to the rest of the printed circuit board at only one end 61a, via two narrow webs 63a. When a force is applied to the end 62a, the lever arm 60a can be bent about the bending axis 70a, thus also resulting in the optical fiber 1 being displaced in a lateral direction in the optical fiber guide 20a.
In order to displace the optical fiber 2 in a lateral direction, transversely with respect to its longitudinal direction, the spring plate 80b is likewise arranged on a movement stepping-down apparatus 6b to displace the optical fiber 2 in a lateral direction. The movement stepping-down apparatus 6b comprises a lever arm 60b which is connected to the rest of the printed circuit board 10 at only one end 61b, via narrow webs, in a similar manner to the lever arm 60a. Otherwise, the lever arm 60b is stamped out of the printed circuit board. The optical fiber 2 can be displaced in the lateral direction in the optical fiber guide 20b by bending a free end 62b.
According to the invention, the optical fiber, to be precise the optical fiber guides 20a and 20b, are therefore displaced in the longitudinal direction of the respective optical fibers by bending two spring plates 80a and 80b. The two optical fibers are displaced in the lateral direction by bending two lever arms 60a and 60b. The spring plates 80a and 80b as well as the lever arms 60a and 60b therefore replace the previously normal precision guides, for example linear guides with ball bearings. The spring plates as well as the two lever arms allow the adjustment forces acting on them to be stepped down. By way of example, a conventional stepping motor may be used to move the two eccentrics 50a and 50b. A large force applied to the spring plates is stepped down by the restoring force of the spring plates to a small displacement of the optical fibers in their longitudinal direction.
In the same way, the lever arms 60a and 60b for displacing the optical fibers in the lateral direction also result in the forces acting at their ends 62a and 62b being stepped down. A large movement resulting from a large force applied to the ends 62a and 62b of the lever arms can produce a much smaller displacement of the optical fiber guides 20a and 20b which are arranged in the vicinity of the bending axes 70a and 70b at the ends 61a and 61b of the lever arms. The optical fibers can therefore be displaced slightly in their lateral direction by a large force applied to the ends 62a and 62b of the lever arms. The step-down ratio is in this case dependent on the length of the lever arms, and can be chosen within wide ranges.
Movement actuators, such as low-cost stepping motors, or else thermal expansion elements or solenoid actuators, can be arranged at the ends 60a and 60b. These cause the lever arms 60a and 60b to be bent about their bending axes 70a and 70b. Non-linear movement changes on the movement actuators, which are caused, for example, by the surface roughness of the eccentrics of the adjustment motors, are in this case also advantageously stepped down by the step-down ratio of the lever arms. This stepping down is further enhanced by the bending of the lever arms, and by the geometric discrepancy from a straight lever arm resulting from this.
According to the invention, the necessary precision positioning of the optical fibers for the splicing process is therefore achieved by a low-cost, relatively coarse movement mechanism, by bending and by appropriate stepping down. This makes it possible to replace costly elements such as precision guides, precision mechanical parts as well as expensive piezo-components by simpler mechanical parts and drive components. The required precision for alignment of the optical fibers is produced again by stepping down by means of a bending apparatus.
The supporting plate 10 is preferably in the form of a printed circuit board. This makes it possible to solder numerous components onto the printed circuit board, such as the electrode holders with their corona-discharge electrical system. Conductor tracks L40a and L40b on the printed circuit board avoids the previously necessary wiring complexity for the electrode holders. The use of a printed circuit board likewise makes it possible to place numerous components, such as the electrode holders, precisely on the printed circuit board by automatic component placement on the printed circuit board with the aid of the normal automatic placement devices for printed circuit board construction.
The spring plates 80a and 80b are connected to the lever arms 60a and 60b via attachment elements S 5, for example screws or rivets. A motor M2a is fitted in a holder under the eccentric 50a. A further motor M2b is fitted under the eccentric 50b. The motors allow the eccentrics 50a and 50b to be rotated in order to bend the spring plates 80a and 80b in the Z direction.
By way of example, low-cost stepping motors may be used as the motors. In addition to the motors and lifting apparatuses illustrated in
Furthermore, image processing devices C1 and C2, for example CCD cameras, are arranged on the lower face. The beam path of these optics is in the form of a cylinder and ends, as can be seen in
An illumination device 90a to illuminate an insertion area for the optical fiber guide 20a is located on the supporting plate 10 in the area of the electrode holder 20a. An illumination device 90b to illuminate an insertion area for the optical fiber guide 20b is located adjacent to the electrode holder 20b. The insertion areas are, for example, in the form of grooves. A further illumination device 90c to illuminate the splice zone is located under the two ends of the optical fibers to be spliced. By way of example, LEDs may be used as illumination devices for illuminating the insertion areas and the actual splice zone.
If the supporting plate 10 is in the form of a printed circuit board, there is no need for complex wiring for the illumination devices either. Voltage supplies L90a for the illumination device 90a, L90b for the illumination device 90b, and L90c for the illumination device 90c may in this case preferably be integrated directly on the printed circuit board.
A camera chip 30a and a camera chip 30b are preferably arranged on the supporting plate 10 for video monitoring of a splicing process. When a printed circuit board is used as the supporting plate, the voltage supply lines L30a and L30b providing the supply can also in this case be arranged on the printed circuit board.
When a printed circuit board is used as the supporting plate, the illumination devices 90a, 90b, 90c and the camera chips 30a and 30b can also in this case be arranged by automatic placement by means of an automatic placement device. It is likewise possible, instead of using different illumination devices on the printed circuit board 10, to provide one illumination device, for example an LED, whose light beam is passed via various deflection mirrors to the insertion areas of the optical fiber guides, and to the splice zone.
The following text describes a modified arrangement of the apparatus for splicing optical fibers, which is particularly suitable for aligning a plurality of optical fibers, a so-called fiber ribbon, for a splicing process.
In this context,
In this context,
The optical fiber guide 20b is likewise arranged on a supporting apparatus 21b, which is connected via a joint G to the spring plate 80b which is arranged on the lever arm 60b, and is connected to a spring plate 80d which is arranged on the lever arm 60d. The supporting apparatus 21b and therefore the entire fiber ribbon 2′ as well can be displaced in a lateral direction Sy transversely with respect to the longitudinal direction of the fiber ribbon 2′ by simultaneous bending of the loose ends 62b of the lever arm 60b and the loose end 62d of the lever arm 60d. Since the spring plates 80b and 80d are connected to the supporting apparatus 21b via joints G, this also ensures in this case that the individual optical fibers in the fiber ribbon 2′ are not twisted.
The lever arms 60a and 60c are bent via a lifting apparatus H1a and a lifting apparatus H1c. The lifting apparatuses H1a and H1c are preferably in the form of eccentrics, which are connected to the motor M1a via a common connecting shaft. The lever arms 60b and 60d are bent by a rotary movement of two lifting apparatuses H1b and H1d in the form of eccentrics. The eccentrics H1b and H1d are connected to the motor M1b via a common connecting shaft. When deliberate rotation is required for fine positioning of the ribbon lateral axes with respect to one another, then two motors may be used instead of one motor for simultaneous bending of the lever arms 60a and 60c, and of the lever arms 60b and 60d. In this case, by way of example, the lifting apparatus H1c is not connected to the motor M1a via the common shaft. The lifting apparatus H1c is in this case driven by its own motor. The lifting apparatus H1b is likewise not driven by the motor M1b via the common shaft. In this case, this is also driven by its own motor.
The lever arms 60b and 60d are used for displacing the supporting apparatus 21b for the optical fiber guide 20b in the lateral direction Sy of the fiber ribbon 2′. For this purpose, the supporting apparatus 21b is connected to the lever arms 60b and 60d via raised areas which are formed by the limbs of the spring plates 80b and 80d. When a force K is applied to the free end of the lever arms 60b and 60d, the supporting apparatus 21b is displaced in the lateral direction Sy.
A bending hinge, for example the joint G illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102005038937.6 | Aug 2005 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE2006/001443 | 8/17/2006 | WO | 00 | 4/1/2009 |
