DE102004030827B4 - Combined device for cleaning and checking the end surfaces of optical fiber connectors - Google Patents

Abstract

Combined device for automated cleaning and inspection of ferrules for optical fiber connectors, with
A glass fiber adapter (GFA) attached to a housing (GE) for fixing a ferrule (FE) of optical connectors,
A cleaning unit (RE) which, by mechanically moving a suitable cleaning material, cleans the end face of the ferrule (FE) at the end of an optical glass fiber (GF),
- And a test unit for checking the state of the ferrule, comprising a CCD camera (KA) with a lens lens (OL) or a CMOS sensor chip with a lens lens (OL) and an integrated image recognition unit, wherein the integrated Image recognition unit reads out and analyzes the image of the CCD camera or the CMOS chip,
wherein the cleaning unit (RE) is movable on the one hand between a rest position and on the other hand a cleaning position under the ferrule to be cleaned,
wherein the objective lens (OL) of the inspection unit, which is arranged under the ferrule to be cleaned, can be guided away via an objective rail (OS) in order to make room for the cleaning unit (RE), so that the space is ...

Description

The The invention relates to a device for the Cleaning and checking the Condition of the end surfaces of connectors for Optical glass fibers according to claim 1.

With An optical communication system is data by means of light pulses from one or more light sources, usually by LASER are realized, over transfer long distances in a glass fiber. This technique draws is characterized by the fact that the transmission capacity is a multiple of the transmission capacity, the can be achieved in purely electrical communication systems. This happens with the technology of wavelength division multiplexing, in which many wavelength or optical carrier frequencies can be transmitted simultaneously in a glass fiber at the same time, the so-called WDM systems. Here you can 160 wavelengths of light or more simultaneously through the fiber.

Around high transmission ranges With such WDM systems, high transmission powers are achievable per wavelength required in the receiver one enough high signal-to-noise ratio is available, that for a faultless receipt of the transmitted Data is necessary. The one for this necessary services are usually between 3 and 6dBm (2 to 4mW) per wavelength. That means that for WDM systems with 160 wavelengths a total light output of 25 or 28dBm (300 to 600mW) through the fiber is passed. Optical amplifiers, which are usually through Erbium doped fiber amplifier (EDFA) are implemented at regular intervals of 50 to 100km on optical links used for damping to compensate for the power through the fiberglass material. Should be between two optical amplifiers a bigger distance be bridged by up to 200km, can amplification techniques are used, the physical Raman effect for the amplification of exploit optical signals, so-called Raman amplifier. For this is a light output of up to 1 W (30 dBm) in addition in the fiber coupled.

Around Furthermore disorders in the transmission in glass fibers over to prevent long distances, which are due to different propagation paths within The glass fibers are called, so-called single-mode optical fibers used. These are designed to be just an electromagnetic Lightmode can spread in it. To achieve this, may the cross section, in which the light output is guided, only a few microns be.

Becomes now in this small cross section the light output of 160 wavelengths of a Transmit WDM systems, Here are very high power densities of several kilowatts reached per square centimeter. If an optical system with Raman amplifiers is used, For example, the power density can be even higher.

Around the various components of an optical fiber system or of a WDM system and to the transmission fiber to join, connectors are used. This will be the end of the fiber provided with a hard glass ceramic, with very high accuracy flattened, a so-called Ferrul. Press through exact pressing Two ferrules make contact between the two glass fibers. With good workmanship and well-cleaned ferrules can thus be achieved that the loss through this connector is less than 0.1dB (2.3%) the light output is.

Are located However, only slight contamination on the ends of a Ferruls, can the damping between two Glasfa fibers amount to a multiple thereof. is For example, dust on the ferrules, the two ends of the connector can no longer be pressed against each other and there is an air gap in the connector between the glass fibers, which reflections causing the quality the transmission strong impair can. The damping the connector can then be 0.5 dB (12%) or more. By Touch The ferrule in the installation and maintenance of optical communications systems can also Impurities through the skin, such as fat, on the ends get a ferrule. This is also a high attenuation in the Plug connection caused. The optical light output is absorbed or reflected and converted into heat in the case of absorption, which the interfaces the fiber is damaged and thus makes us unusable. This can cause a failure of the optical transmission system to lead. A failure of an optical transmission system is a high cost because troubleshooting is difficult and tedious is and by failures Escape profits.

Therefore, it is very important that the ferrules of optical connectors are cleaned with the utmost care before assembly. Several techniques are already available today. The simplest method is to clean the ferrule ends with optical lens cleaning wipes. Special cleaning tools for optical glass fibers are also available. Meanwhile, complex systems using ultrasound methods are also available (see US 2003/169991 A1 ) to dirt from ends to remove the ferrule.

• – vor dem Reinigungsvorgang muss geprüft werden, ob und welcher Grad der Verschmutzung vorliegt
• – nach dem Reinigungsvorgang muss der Erfolg des Reinigungsvorgangs geprüft werden und weiterhin, ob ein Defekt an der Steckverbindung vorliegt und somit eine einwandfreie Steckverbindung gewährleistet ist. Dies geschieht üblicherweise mit speziellen Mikroskopen, an deren Ende das Ferrul eingesteckt werden kann.

These techniques have in common that in addition to the cleaning process further steps are necessary:

• - Before cleaning, it must be checked if and what degree of contamination is present
• - After the cleaning process, the success of the cleaning process must be checked and continue, if there is a defect in the connector and thus a proper connection is guaranteed. This is usually done with special microscopes, at the end of the ferrule can be inserted.

Out WO 98/14810 A2 a device for the automated construction of an optical fiber connector and its inspection (ADS) is known, which consists of a plurality of functional units and including in the plug connection unit, a device for cleaning the mounted ferrule and in the inspection unit, a device for checking the mounted ferrule and to examine the ferrule on further possible errors. Unlike the device presented here, this is a very large production machine that is not suitable for carrying out installation or maintenance work on WDM systems in their intended place of use. Moreover, in WO98 / 14810 A2 the objective lens (OL) of the test unit in the case of a cleaning process not wegführbar to make room in the case of a cleaning process - the cleaning unit, which can go to their cleaning position and can start the cleaning process. In addition, the lens lens is not in WO98 / 14810 A2 not provided with a protective cover to prevent contamination. In addition are out GB 2 304 276 A and US 2004/0033050 A1 Equipment for cleaning and checking the end surfaces of connectors for optical fibers known. In these devices, however, a manual intervention of the user between the individual cleaning steps, for example by plugging the connector from the cleaning unit to the test unit, is necessary. The automation described in this document is not given in GB 2 304 276 A and US 2004/0033050 A1 ,

• – Inspektion der Glasfaserendfläche
• – Reinigung der Glasfaserendfläche
• – erneute Inspektion der Glasfaserendfläche zu einem Arbeitsschritt reduziert werden. Diese Aufgabe wird mit dem erfindungsgemäßen Gerät nach Anspruch 1 erfüllt. Vorteilhafte Ausgestaltungen ergeben sich aus den Unteransprüchen.

The task is now to provide a device to make inventions, with which the installation and maintenance of WDM systems can be simplified and with the necessary steps described above

• - Inspection of the glass fiber end face
• - Cleaning the glass fiber endface
• - Re-inspection of Glasfaserendfläche be reduced to a single step. This object is achieved with the device according to the invention according to claim 1. Advantageous embodiments emerge from the subclaims.

In the present invention, the two steps for Cleaning a glass fiber endface - with a Microscope the end face check, clean the ferrule and recheck the end face - all in one single device automated.

In an inventive Device will that Ferrul in a matching to the respective connector standard of the ferrule Socket fixed. The end face of the Ferrules are fitted with a matching optics on a CCD camera or a CMOS sensor chip displayed. The image of the camera is from an integrated into the device Microprocessor read out and analyzed. At the same time that will Picture on a likewise in the device built-in monitor output. Detects the image analysis software contamination of the ferrule, so the cleaning process begins. This will be first the closest to the ferrul lying lens (lens) mechanically away from the ferrule and provided with a protective cover. Now a cleaning mechanism pulled up to the ferrule, and the ferrule is cleaned. To completed cleaning, the cleaning mechanism is back in their Rest position moves and the lens will also be back to his Starting position moves. Again a camera shot is taken and the cleaning result is displayed on the monitor and by the Image analysis software checked. If the cleaning process was unsuccessful, the above becomes Procedure repeated.

The Position of either the lens or camera lens or both can be adjusted by a processor-controlled fine drive be that the picture of the ferrule on the opto-electronic Transducer (CCD or CMOS) is sharp and the magnification does not change.

A significant advantage of the device according to the invention is the fact that on the one hand, the duration of the entire cleaning process is reduced and above all by the quick and easy cleaning this is performed at all. Otherwise, cleaning of the ferrule is often "forgotten" or insufficiently performed by service personnel, with consequences as described above.Some telecommunication companies have resorted to critical fiber connections by welding ("splicing") the fiber ends for the above reasons to realize. This in turn has the disadvantage that it is very complicated to exchange or maintain individual components of a WDM system. By a device according to the invention is eliminated the need to weld the glass fibers.

One Another essential advantage of the device according to the invention is the possibility during the in the invention described automatic cleaning process Ferrule perform other activities. There all necessary steps of the cleaning process automatically A microprocessor control can be performed in this Time other important activities be performed, such as a documentation of the work carried out, checking other connections with other methods. An acoustic signal can be used to to the successful implementation indicate the cleaning procedure of the ferrule. Especially advantageous is to see that an integrated image recognition more damage the surface can recognize the ferrule. This can be done by appropriate representation be made visible on the display of the device according to the invention.

hereby can be avoided that a no longer suitable ferrule continues is used, resulting in failures of the system can. Advantageously, the device for cleaning and for checking the end surfaces of connectors for optical fiber easily transportable and durable in one hand.

One embodiment The invention will be explained in more detail below with reference to the drawings.

1 : a possible overall arrangement of the individual components

2 : a possible arrangement of the optics and cleaning mechanics shown.

1 shows an exemplary representation of an inventive device. The device is installed in a housing (GE). For the user from the outside only a liquid crystal screen (LCD), some buttons (TA) to operate the device and a plug adapter for inserting the fiber (GFA, see 2 ) visible, noticeable. Inside the housing GE is located next to the in 2 cleaning / microscopy mechanics explained in more detail an electric accumulator (AK), which provides the energy for the device, so that independent of the power supply operation is ensured. The accumulator feeds the entire electrical components of the device according to the invention. A single board computer (SBC) takes over the entire control of the device. The SBC reads the image from the camera and stores and processes it in its internal memory. The camera image is also output to the liquid crystal monitor (LCD). The TA keys can be used to control the behavior of the SBC. The SBC also controls the cleaning mechanism and the process of the lenses.

2 shows an exemplary representation of the optics and the cleaning unit of the inventive device. The plug-in connection of the glass fiber (GF), at the end of which the ferrule (FE) to be cleaned, is fixed in a corresponding glass fiber adapter (GFA). The optics of the device, consisting of an objective lens (OL), which is mounted on the movable lens holder (OH), and an eyepiece lens (OK), is positioned by means of motors that on the camera (KA) (see 1 ) creates a sharp image of the cleaned ferrule (FE). This is controlled by the image recognition by software. If ferrule fouling (FE) is detected, the entire unit, lens holder (OH) and lens lens (OL) are guided down the lens mount (OS) by a motor to make room for the cleaning unit (RE) , Optionally, the lens mount (OS) can also be arranged horizontally. The cleaning unit (RE) is guided by another motor via the cleaning rail (RS) under the Ferrul (FE) to be cleaned. The cleaning material fixed on the surface of the cleaning unit, which may be realized for example by a lens cleaning cloth, is pressed against the ferrule (FE) from below and moved in the horizontal direction. As a result, a mechanical cleaning of the ferrule (FE) is achieved. When cleaning is complete, the cleaning unit (RE) returns to its original position and the optics are placed back under the ferrule (FE). This can be used to check the success of the cleaning process or to detect damage to the ferrule (FE).

AK

Accumulator / battery

FE

ferrule

GE

casing

GFA

Fiber Adapter

GF

glass fiber

KA

camera

LCD

Liquid crystal screen

OH

lens holder

OK

eyepiece

OIL

objective lens

OS

lens rail

RE

cleaning unit

SBC

single Board computer

TA

keyboard

Claims (9)

Combined device for automated cleaning and inspection of ferrules for optical fiber connectors, comprising: - a fiber optic adapter (GFA) attached to a housing (GE) for fixing a ferrule (FE) of optical connectors, - a cleaning unit (RE), moving by mechanical movement suitable cleaning material cleans the end face of the ferrule (FE) at the end of an optical glass fiber (GF), and a test unit for verifying the state of the ferrule, comprising a CCD camera (KA) with an objective lens (OL) or a CMOS Sensor chip with a lens lens (OL) and an integrated image recognition unit, wherein the integrated image recognition unit reads the image of the CCD camera or the CMOS chip and analyzed, the cleaning unit (RE) on the one hand between a rest position and on the other hand, a cleaning position the ferrule to be cleaned is movable, wherein the arranged under the ferrule to be cleaned lens lens (OL) of Pr a lens (OS) is wegführbar to make the cleaning unit (RE) space, so that the cleaning unit (RE) can take the cleaning position under the Ferrul to be cleaned, with the lens lens (OL) in her weggested Position is provided with a protective cover, wherein the sequence of a first step of checking the state of the ferrule, a second step of cleaning the end face of the ferrule and a third step of verifying the state of the ferrule is automated, and wherein the combined device by means of a electric accumulator is operated. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to claim 1, characterized in that cleaning the ferrule (FE) with a cleaning material stocked Cylinder, which presses on the end face of the ferrule (FE) and while rotating. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to one of claims 1 or 2, characterized that the image of the end face of the ferrule (FE) on the CCD camera (KA) or the CMOS sensor chip storable and electronically processable. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to claim 3, characterized in that the electronically stored and processed image of the ferrule (FE) through a screen (LCD) or a printer or another suitable display medium is viewable. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to claim 3, characterized in that the electronically stored and processed image of a ferrule (FE) is transferable to other electronic storage media. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to one of Claims 1 to 5, characterized that the test unit Detects if the end face the ferrule (FE) on the one hand in a perfect or otherwise is in a damaged or soiled condition. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to claim 6, characterized in that the test unit in the case of a damaged or soiled end surface of the Ferruls (FE) performs an analysis of the flaws. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to claim 6, characterized in that the test unit in the case of a faultless end face of the ferrule (FE), that the second step of the automated cleaning of end face of the ferrule (FE) and the third step of rechecking the Condition of the ferrule can not be performed. Combined device for automated cleaning and inspection of ferrules for connectors Optical glass fibers according to one of claims 1 or 2, characterized that the cleaning material is interchangeable, without any need for readjustment the one in the device existing components is necessary.