Abstract:
The present invention provides an interconnect cable having an electroluminescent element disposed therein in order to facilitate locating the interconnect cable. The electroluminescent element is activated by a driver that may be selectively applied to specified driver ports located on end connectors of the cable. The electroluminescent element may be incorporated within the entire length of the cable, or only along selected sections of the cable.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This Application claims the priority of U.S. Provisional Application No. 60/692,868 filed on Jun. 21, 2005, the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to identification of cables that carry electronic signals, and more particularly, the present invention is directed to the identification of patch cables, such as those used in computer and communication networks. 
     BACKGROUND OF THE INVENTION 
     Computer and communication networks rely on patch or interconnect cables to connect components of the networks to one another. To facilitate troubleshooting, maintenance, and reconfiguration of signal paths used within the networks, it is critical that each and every interconnect cable be identified as to its origination and termination. This identification requires recordation of each and every connection. In networks with a large number of interconnected components, keeping accurate track of and managing the connections becomes a significant effort. Network problems may occur if interconnections are not accurately and timely recorded. 
     In the maintenance of patch panels, paper-based documentation is still widely used. With large networks, the documentation may be recorded in the form of record books where each of the connections are manually recorded. Paper-based documentation obviously has disadvantages in terms of required effort and accuracy. 
     Verifying existing connections when network problems arise can be extremely time consuming. When a cable has become inadvertently disconnected from its patch panel, or in the attempt to identify a particular cable within a large network, the recorded documentation may provide some assistance, but the documentation alone does not locate the actual position of the cable or its path between connected components. 
     Automated systems have been developed for monitoring and recording cable connections; however, these known systems require specialized patch panels that monitor connections at the panel, displays on patch panel racks, and LEDs on patch panel ports. Additionally, such systems require special software for administering the patch panel connections. These systems are still deficient in providing the capability to locate an end of a cable that has become disconnected from its port, or a cable that is connected to a port other than the port recorded as being the designated port for the particular cable. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an electroluminescent patch or interconnect cable is provided that quickly and easily allow a user to identify not only the ends of the interconnect cable, but also the actual path that the interconnect cable travels. 
     An electroluminescent fiber is incorporated within the patch cable, preferably partially covered by or encapsulated within the sheath of the interconnect cable. As understood in the art, an electroluminescent fiber or element generally refers to a light producing device wherein a pair of electrodes combined with a semi conductive material, such as phosphor, produce light when an electrical current is applied across the electrodes due to exitation of the phosphor material. Electroluminescent elements are also referred to as cold illumination sources that generally have low operating current requirements, and have a long service life in comparison to conventional light bulbs. 
     The interconnect cable further includes an end connector attached at each end of the cable enabling it to be plugged into the designated panels/components. A driver port is incorporated on each end connector. In order to activate the electroluminescent fiber, a driver is coupled to a selected one of the driver ports. Regardless of whether the end connectors are engaged with a port of a patch panel/component, or are disconnected from a patch panel/component, the user may activate the electroluminescent fiber by applying the driver to one of the driver ports thereby illuminating the portion of the cable in which the electroluminescent fiber is incorporated. 
     Preferably, the driver is provided in the form of a portable device that may be hand carried to the work site, the device including a driver circuit and a power supply. The driver circuit conditions the output of the power supply to match the activation requirements of the electroluminescent fiber to be activated. 
     In one preferred embodiment, the electroluminescent fiber extends the entire length of the interconnected cable. Thus, when the fiber is activated, the entire length of the cable is illuminated. 
     In another embodiment, the electroluminescent fiber may be segmented, and may be incorporated to extend only along selected lengths of the interconnect cable. For example, it may only be necessary to provide illumination at the ends of the cable. Accordingly, the electroluminescent fiber could be provided in two separate segments, one segment being incorporated at each end of the cable. If the fiber is to be provided in segments or sections, the separated segments or sections are joined by a conductor that transmits the driver signal to each of the separated sections. 
     The type of electroluminescent fiber may be chosen which provides the desired illumination intensity, as well as color. When the electroluminescent fiber is incorporated within a sheath of the interconnect cable, the sheath must be at least translucent thereby allowing the electroluminescent fiber to transmit light therethrough. 
     Additional features and advantages of the present invention will become more apparent from a review of the following detailed description, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a standard patch panel including a plurality of interconnect cables connected to the patch panel; 
         FIG. 2  is a schematic depiction of an interconnect cable in accordance with embodiments of the present invention; 
         FIG. 3  is an enlarged longitudinal cross-section of  FIG. 2 ; 
         FIG. 3A  is a greatly enlarged cross-section of a portion of  FIG. 3 ; 
         FIG. 4  is a transverse cross-section of the interconnect cable taken along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  illustrates a transverse cross-section of another embodiment of the present invention; 
         FIG. 6  illustrates a prior art electroluminescent fiber construction; and 
         FIG. 7  illustrates another prior art electroluminescent fiber construction. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a prior art patch panel  10  is shown having a mounting plate  12  along with a plurality of numbered connector ports  14  integrated therein. Interconnect cables  16  have corresponding end connectors  18  that are plugged in the respective connector ports  14 . For clarity of illustration, not all of the connector ports are shown with corresponding interconnect cables. The connector ports  14  may be identified by their corresponding number, and may further include port identifiers  20  that serve as additional indicia for identifying the particular connector port. 
     Various cable keepers  22  may be mounted adjacent to the patch panel  10  in order to more orderly maintain the interconnect cables in place; however, as one can appreciate, when a particular patch panel has a great number of interconnect cables connected thereto, the cables become an unmanageable tangle. In some patch panels, particularly in laboratory environments, there may be hundreds of interconnect cables present, making it difficult to troubleshoot and maintain the panel because of the large number of cables present. 
     Referring to  FIGS. 2-5 , the electroluminescent patch cable and system of the present invention are illustrated.  FIG. 2  illustrates an interconnect cable  24  that interconnects a pair of components  25 , such as a patch panel, server computer, switch board, or other known computer or communication components. The interconnect cable  24  features a connector  28  attached at opposite ends of the cable. The interconnect cable  24  has a sheath  30 , and one or more signal lines  26  housed within the sheath. 
     In general, the connectors  28  are configured to interconnect with a mating connector port incorporated upon the network component  25 . Accordingly, it will be appreciated that the interconnect cable  24  can be deployed to permit signals and/or power to be passed between the components  25 . 
     Furthermore, it shall be understood that the particular type of interconnect cable to be provided may be in the form of a ribbon cable, or any other particular configuration as dictated or suggested by the particular application. 
     With reference particularly to  FIG. 3 , the arrangement of the interconnect cable  24  is shown in more detail. Each end connector  28  includes a mechanical mating structure  38 , which may include interconnection points, pins, contact points or some other structure.  FIG. 3  generally illustrates mating structure in the form of pins  29  which allow the ends of the interconnect signal lines  26  to operably connect to the components  25 . The signal lines  26  may comprise electrically conductive signal or optical signal lines. Thus, the interconnect cable  24  in accordance with the embodiments of the present invention may function to operably interconnect devices/components  25  by transferring signals over the signal lines  26 . 
       FIG. 3  also schematically illustrates driver conductors  37  that interconnect the electroluminescent element  32  to a driver receptacle  38 . Preferably, each end connector may incorporate a driver receptacle to permit activation of the element  32  at either end of the cable. A driver  40  engages the interconnect cable via one of the driver receptacles  38 . The driver  40  provides the specified power for activating the electroluminescent element.  FIG. 3  further illustrates an elongate, tubular shaped electroluminescent element having its own cover or sheath  34  that surrounds the electroluminescent element. The sheath/cover  34  may be made of a flexible plastic, vinyl, or other flexible material having a desired color that therefore allows a desired colored light to be emitted from the electroluminescent element. 
       FIGS. 6 and 7  illustrate example constructions of electroluminescent elements that may be used with the present invention. These constructions correspond to those disclosed in the U.S. Pat. No. 6,851,818, this reference being incorporated herein in its entirety for purposes of disclosure of the constructions. Although specific examples are provided in  FIGS. 6 and 7 , it shall be understood that the electroluminescent element of the present invention can be made with other alternative constructions. Therefore, these particular constructions shall not be interpreted as limiting the electroluminescent fiber of the present invention to a particular construction. 
     Referring to  FIG. 6 , a single filament construction is shown. It includes a central wire conductor  50  serving as the inner electrode, an insulating layer  52 , a phosphor layer  54  placed over the insulating layer, and a layer  56  of transparent material having high electrical conductivity and serving as the outer electrode of the electroluminescent fiber. Layer  56  is electrically connected to one side of a voltage source  62  by a wire  60  connected to layer  56 , and the opposite side of the voltage source  62  is connected to the inner electrode  50 . An electrical field is generated for creating luminescence in the phosphor layer  54 . The single filament construction illustrated also further includes the outer light conductive sheath or cover  34  of uncolored or color transparent plastic material to permit transmission therethrough of the light generated within the electroluminescent fiber. The voltage source in the preferred embodiment is provided by the output of driver  40 . The voltage source may be AC, or a pulsed DC. Thus, the electroluminescent element shown in  FIG. 6  can be described essentially as a capacitor with one transparent electrode and a special phosphor material in a dielectric. The phosphor glows when a voltage source is applied across the electrodes. 
       FIG. 7  illustrates another prior art construction for an electroluminescent fiber. More specifically,  FIG. 7  illustrates a two-filament construction, therein generally designated as  32 ′. In this construction, there are two inner electrodes  70  and  72 , each constituting one of the two light generating filaments of the electroluminescent element. Each, filament further includes respective insulating layers  74  and  75 , respective phosphor layers  76  and  77 , and respective transparent electrically conductive layers  78  and  79 . Conductors  82  are used to apply a voltage  84  to the inner electrodes  70  and  72 . The outer light conductive sheath or cover  34  encloses both of the filaments to produce a relatively flat electroluminescent element having the two light generating filaments therein. Use of two light generating filaments produces a higher light output. 
     Referring to  FIG. 3A , the connection between the electrodes of the electroluminescent element and the conductors  37  are illustrated. More specifically,  FIG. 3A  illustrates the present invention adopting the particular construction of the electroluminescent fiber shown in  FIG. 6 . Accordingly, it is shown that the inner electrode  50  and the outer electrode  56  are electrically coupled to the conductors  37  so that when the driver  40  is engaged with the driver port  38 , power is provided to the electroluminescent element  32 . 
     Referring to  FIG. 4 , a cross-section is illustrated wherein the sheath  30  surrounds the plurality of signal lines  26 . The electroluminescent element  32  is shown as being encapsulated within the sheath  30 , thus, the cable maintains a substantially round cross-section. One manner in which to incorporate the electroluminescent element within the sheath  30  is to emplace the element  32  during the molding process of the sheath. Those skilled in the art can envision other ways in which the element  32  may be efficiently formed with the sheath  30 . 
     In yet another embodiment of the present invention as shown in  FIG. 5 , the electroluminescent element  32  may have some portion that remains exposed, and the remaining portion of the electroluminescent element being attached to the sheath. Therefore, the sheath  30  would not have to be translucent or transparent. More specifically, a portion of the sheath  30  that contacts the electroluminescent element  32  has a radial extension  31  that captures the electroluminescent element, but leaves some portion of the outer surface of the electroluminescent element exposed. Accordingly, the sheath  30  does not have to be translucent or transparent, and the portion of the electroluminescent element exposed adequately transmits light. 
     As mentioned above, the driver  40  in accordance with embodiments of the present invention includes a power source  42  and driver circuit  44 . The driver circuit  44  modulates the signal provided by the power source  42  in order to match the activation requirements of the electroluminescent element. It is also contemplated within the present invention that the driver  40  could include a manual switch (not shown) that would allow a user to set the driver  40  to provide the correct power for activation of the electroluminescent element. Preferably, the driver  40  would be a hand-held device having an extension that would conveniently fit within the driver receptacle  38 . By attaching the driver  40  to the receptacle  38 , electrical connection would be made between the output of the driver and the conductor  36  thereby activating the electroluminescent element. 
     In some circumstances, it is desirable to incorporate the electroluminescent element  32  along the entire length of the interconnect cable. In other circumstances it may only be necessary to incorporate the electroluminescent element along selected lengths of the interconnect cable, such as providing the electroluminescent element in two separate segments or sections which extend from the respective end connectors  28 . If the electroluminescent element  32  is to be segmented or separated, the separated segments or sections may be electrically connected by conductors  36 , as shown in  FIG. 2 . The conductors  36  could simply include a pair of wire conductors interconnecting the electrodes of the separated segments thereby conveying power between the separated segments for activation. 
     The advantages of the present invention are clear. Electroluminescent patch cables have been provided that enable a user to positively identify the origination and termination of a particular cable, as well as to trace the path of the cable as it may extend through a complex bundle or group of cables used in a large network. The visual indication provided by the electroluminescent fiber provides an easy means of identification for the user, yet the identification does not require expensive hardware, software, or other supporting components. A hand-held driver also makes identification of cables quick and efficient, and does not require the user to disconnect any cables or otherwise modify or interrupt the particular network in which the cables are found. 
     The particular embodiments described above are intended to explain the best mode presently known in practicing the invention and to enable others skilled in the art to utilize the invention in such or in other embodiments and with various modifications required by their particular application or use of the invention. Therefore, it is intended that the appended claims be construed to include the alternative embodiments to the extent permitted by the prior art.