Electrical connector with light transmission means

Abstract: A modular jack (10,50) is adapted for connecting a cable terminated with a plug to a circuit board (24). The jack includes a housing (12) having a front face (14) with a receptacle (18) for receiving the plug, a rear face (48) and a bottom face (16) adapted for mounting on the circuit board (24). A light guide (40,52) is provided on the housing (12) and includes a front end (40c,52c) at the front face (14) of the housing and a remote end (40d,52d) near the bottom face (16) of the housing for guiding light from a source (34) thereof on the circuit board (24) to the front of the housing.

Description: Field of the Invention This invention generally relates to the art of electrical connectors and, particularly, to an electrical connector which has a built-in light transmission means for visual indication. Background of the Invention Electrical connectors having built-in indicator lights have been known for some time. In these connectors, the indicator lights typically are located at the front of the connector. A typical connector may include an integral LED device to emit a light which indicates an operational function such as the reception or transmission of data or voice signals, verification of a good connection between separate pieces of equipment, indication when power is on or off, indication of a defect in a network transmission or any other state or condition in the equipment with which the connector is operatively associated. Visual light indicating connectors are popular in modular jacks or similar types of connectors commonly used in telecommunications and data networking equipment. These jacks often are mounted on a circuit board to which they are to be connected. Problems have been encountered in incorporating such light indicating devices, such as LED devices, directly onto the connector due to the ever-increasing miniaturization of telecommunications and data networking equipment. There simply is not enough space to mount many LED devices directly on the connector housing. In addition, regardless of the size of the connector or jack, connectors which include light transmitting devices are expensive to manufacture and assembly for an otherwise relatively inexpensive component. Also, integrating active visual indicators can introduce serious electromagnetic interference(EMI), due to the relatively high vertical distance of the associated indicator wiring from the PCB ground plane. The present invention is directed to solving these problems by providing an electrical connector or modular jack which has light indicating capabilities without mounting the source of the light directly on the connector itself. An electrical connector of the kind refered to in the preamble of claim 1 is known from EP-A 0 365 698. The light guide means have extensions for being fixed onto a member which includes circuit board connecting elements shown as terminals and is mounted onto the circuit board. The light guide means is arranged pick-a-back onto such member having the circuit board connecting elements, not inside it. Summary of the Invention With the invention, a better miniaturization of electrical connectors is possible which are capable of transmitting and indicating light for various visual indication purposes. The invention is defind in claim 1. In the exemplary embodiment of the invention, a modular jack is adapted for connecting a cable terminated with a plug to a printed circuit board. The jack includes a housing having a front face with a receptacle for receiving the plug, a rear face and a bottom face adapted for mounting on the printed circuit board. A light guide means is provided on the housing and including a front end at the front face of the housing and a remote end near the bottom face of the housing for guiding light from a source thereof on the printed circuit board to the front of the modular jack. As disclosed herein, the light guide means is provided by a one-piece, L-shaped light pipe independent of the housing. The L-shaped light pipe includes top and rear legs disposed in recessed areas in the outside of top and rear walls of the housing. The generally perpendicular legs of the L-shaped light pipe are joined at a juncture which includes an oblique reflecting surface. The light pipe is a homogeneous structure fabricated of such materials as a substantially clear polycarbonate material. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIGURE 1 is a perspective view of a dual-receptacle modular jack incorporating the concepts of the invention; FIGURE 2 is a front-to-rear vertical section through the modular jack at a location to best illustrate the configuration of one of the L-shaped light pipes, with the jack mounted on a printed circuit board; FIGURE 3 is a fragmented vertical section taken generally along line 3-3 of Figure 2; FIGURE 4 is a fragmented section taken generally along line 4-4 of Figure 3; FIGURE 5 is a side elevational view of a modular jack incorporating an alternate embodiment of light pipe; FIGURE 6 is a rear elevational view of the modular jack of Figure 5; and FIGURE 7 is a side elevational view of one of the light pipes used in the embodiment of the modular jack shown in Figures 5 and 6. Detailed Description of the Preferred Embodiments Referring to the drawings in greater detail, and first to Figure 1, a dual-receptacle modular jack, generally designated 10, incorporates the concepts of the invention. The jack includes a dielectric housing, generally designated 12, which includes a front face 14 and a bottom face 16. A pair of plug-receiving receptacles, generally designated 18, open in front face 14, and the bottom face is adapted for mounting on a printed circuit board. Therefore, the modular jack is adapted for connecting a pair of cables terminated to a pair of plugs, received in receptacles 18, to the printed circuit board. Lastly, jack 10 includes a stamped and formed sheet metal shield, generally designated 20, substantially surrounding the top, sides and rear of housing 12. The shield has downwardly projecting feet 22 for insertion into appropriate holes in the printed circuit board and for solder connection to ground traces on the board and/or in the holes. Referring to Figures 2-4 in conjunction with Figure 1, it can be seen that housing 12 of modular jack 10 is adapted for mounting on a printed circuit board 24 by means of a pair of mounting posts 26 projecting from bottom face 16 of the housing and inserted into appropriate mounting holes 28 in the circuit board. Although only one mounting post 26 is visible in the drawings, two mounting posts are provided at opposite ends of housing 12 and connector 10. As is known, the connector also includes a plurality of contacts or terminals 30 (Fig. 2) projecting into each receptacle 18 for engaging a plurality of contacts on the plug which is inserted into the respective receptacle. The terminals have tail portions 30a extending below bottom face 16 of the housing and into appropriate holes 32 in the circuit board for solder connection to circuit traces on the board and/or in the holes. Before proceeding with a further explanation of the details of modular jack 10, it should be pointed out that the modular jack does not include a light emitting device directly on the jack or connector as is prevalent in the prior art. In contrast, the system of the invention contemplates a light source, such as at least one LED, generally designated 34, mounted on circuit board 24. The LED includes a pair of terminals 34a which extend downwardly through appropriate holes 36 in the circuit board whereby the terminals can be solder connected to appropriate circuit traces on the board and/or in the holes. With modular jack 10 being precisely located on the circuit board by means of mounting posts 26, shield feet 22 and terminal tail portions 30a, precise mounting locations for LED's 34 can be determined prior to mounting the jack onto the board. Turning back to the details of modular jack 10, the jack includes a light guide means in the form of a one-piece, L-shaped light pipe, generally designated 40. In dual-receptacle connector 10, there are two such light pipes for each plug receptacle 18. Each one-piece light pipe is independent of the connector housing 12 and is a homogeneous structure fabricated of such materials as a substantially clear polycarbonate material. More particularly, each L-shaped light pipe 40 defines a top leg 40a and a rear leg 40b which are generally perpendicular to each other. The top leg terminates in a front end 40c of the light pipe which is located at front face 14 of the housing as best seen in Figure 2. Rear leg 40b terminates in a remote end 40d of the light pipe near the bottom face of the housing. Actually, remote end 40d of the light pipe is located immediately above a respective one of the LED's 34. Top and rear legs 40a and 40b, respectively, of the light pipe are located in recessed areas 42 and 44, respectively, in the outside of top and rear walls 46 and 43, respectively, of housing 12. Therefore, the L-shaped light pipe is easily assembled to the housing by laying the pipe into the open recessed areas prior to assembling shield 20 to the housing. Rear leg 40b of the light pipe includes a shoulder 40e which locks to the housing to help hold the light pipe in position. With front end 40c of light pipe 40 being located at front face 14 of the housing, and with remote end 40d of the light pipe being located immediately above a respective one of the LED's 34, the L-shaped light pipe is effective as a light guide means to direct the light from the remote location of the LED to the front of the modular jack. To this end, an oblique reflective surface 49 is formed on the light pipe at a juncture 40f between the generally perpendicular legs 40a and 40b of the light pipe to reflect or deflect the light rays from the bottom LED to the front of the jack. In essence, reflective surface 49 is at a 45° angle to both the axes of perpendicular legs 40a and 40b of the L-shaped light pipe. Referring back to Figure 1, it can be seen that there are four front ends 40c of four light pipes exposed at the front face of the modular jack, two for each plug-receiving receptacle 18 of the dual-receptacle jack. Figure 3 shows two LED's 34 at opposite sides of one of the plug receiving receptacles 18 in alignment with two remote ends 40d of two light pipes. This exemplifies the advantages of the invention wherein the mounting of LED's or other light sources directly on the connector or jack is totally obviated. More than one indicator light often is used on a single connector. For instance, if indicator lights are used for purpose of testing circuits on a network or communications interface card on which the connector is installed, at least two such indicator lights are required, compounding the problem of lack of space on the connector for the lights and compounding the assembly and manufacturing costs involved in mounting the lights directly on the connector or jack itself. Figures 5-7 show an alternate embodiment of the invention wherein generally L-shaped light pipes are used in a modular jack, generally designated 50, which includes only a single receptacle 18 opening at a front face 14 of the jack housing 12. Again, the housing includes a pair of mounting posts 26 for mounting the jack onto a circuit board. Again, jack 50 incorporates a pair of generally L-shaped light pipes, generally designated 52, defining a top leg 52a and a rear leg 52b, with the top leg defining a front end 52c of the light pipe at front face 14 of the jack, and with rear leg 52b defining a remote end 52d of the light pipe near the bottom face 16 of the jack. The jack and its housing is recessed, as at 54, to accommodate LED's mounted on the printed circuit board separate from the jack. Figure 7 shows one of the light pipes 52 removed from jack 50 for purposes of illustration. Whereas light pipe 40 in the embodiment of Figures 2-4 has generally perpendicular legs joined at a right-angled juncture 40f, requiring the use of oblique reflecting surface 49, legs 52a and 52b of light pipe 52 are joined by a gradually curved juncture 52f. With the light pipe being fabricated of a homogeneous structure, such as of substantially clear polycarbonate material, the outside surfaces of the light pipe around gradual curved juncture 52f are effective to gradually guide the light rays through the juncture from remote end 52d of the light pipe to front end 52c of the light pipe. Therefore, the gradually curved, L-shaped light pipe 52 is effective as a light guide means for directing light from the remote LED to the front face of the connector. In the embodiment of Figures 5-7, the L-shaped light pipes 52 are mounted in jack 50 from the rear of housing 12. Specifically, top legs 52a are inserted into cored-out passages 58 in the housing in the direction of arrow "A" (Fig. 5). When the light pipes are fully inserted, rear legs 52b seat in open vertical recesses 60 at the rear of the housing. It will be understood that the invention may be embodied in other specific forms without departing from the central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims: An electrical connector for mounting on a circuit board (24) which has at least a light source (34) mounted thereon, comprising: a plurality of terminals (30); a housing (12) for mounting the terminals on the circuit board(24);and light guide means (40,52) of general L-shape having a first end (40d, 52d) adjacent the light source (34) and a second end (40c, 52c) extending through a wall for being exposed to view, characterized in that said housing (12) of the connector (10, 50) has a bottom face (16) adapted for mounting on the circuit board (24) with the first end (40d, 52d) of the light guide means (40, 52) facing the light source (34), a front face (14) adapted for exposing the terminals (30) and the second end (40c, 52c) of the light guide means (40, 52), side faces and a top face as well as a rear face, and in that said light guide means (40,52) is shaped as a one piece light pipe or a plurality of such light pipes dependent on the number of light sources (34) on the circuit board (24), each having a top leg (40a, 52a) and a rear leg (40b, 52b) which extend along said top and rear faces of said housing (12). The connector of claim 1 wherein said light pipe (40) is disposed in a recessed area (42,44) in the outside of the top and rear wall (46, 48) of the housing (12). The connector of Claim 2 wherein a shield (20) surrounds the top, side and rear faces of the housing (12) so as to enclose said recessed areas (42,44) The connector of any of claims 1 - 3 wherein said light pipe (40,52) is a homogeneous structure fabricated of substantially clear polycarbonate material. The connector of any of claim 1 - 4 wherein said legs (40a, 40b) extend generally perpendicularly to one another and being joined at a jucture (40f) which includes an oblique reflecting surface (49). The connector of any of claims 1 - 5 wherein said front face (14) is provided with a receptacle (18) for receiving a plug so as to make the connector to a modular jack.

Inventors: KEMPF RANDY JOE, ROBERTS JAMES T, TALEND DONALD R, WALSH CHARLES T, KEMPF, RANDY JOE, ROBERTS, JAMES T., TALEND, DONALD R., WALSH, CHARLES T.
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1998
Main classification: H01R24
IPC codes: H01R13, H01R12, G02B6