Abstract:
A communication device and overmold adapted to minimize the feedback, acoustic coupling, and seismic vibration between a speaker and microphone in close proximity, as is typically found in hands-free headsets, is provided. This invention, through the use of specific structures absorbs unwanted noise and sound waves thereby improving the performance of the communication system as a whole. The complete system of this invention is provided in several embodiments, including an embodiment where the microphone is inserted within the overmold structure, an embodiment where the microphone is a boom microphone and an embodiment where the microphone is somewhat remote (a few inches) down from a miniaturized overmold and is provided with an ON/OFF switch.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to devices and methods for decoupling microphones and speakers that are in close proximity to each other. More specifically, this invention relates to devices and methods, which provide microphone-speaker decoupling through the use of an acoustic molded device. 
     2. Description of Related Art 
     A variety of different methods and devices have been proposed for controlling the interference between a speaker—microphone pair in a communications system. Generally however, these devices and methods are ineffective with speakers and microphones in close proximity, while other devices require the use of a material or materials, which are difficult and expensive to manufacture effectively. 
     The reader is referred to the following U.S. patent documents for general background material: U.S. Pat. Nos. 4,334,315, 4,546,267, 4,588,867, 4,696,045, 5,164,984, 5,210,792, 5,222,151, 5,228,092, 5,345,509, 5,448,637, 5,497,182, 5,504,812, 5,511,132, 5,521,982, 5,544,253, 5,586,195, 5,606,607, 5,613,222, 5,659,620, 5,664,014, 5,687,230, 5,692,059, 5,729,615, 5,745,579, 5,757,934, 5,761,298, 5,787,166, 5,790,684, 5,793,865, 5,844,984, 5,845,197, 5,875,251, 5,909,490, 5,933,506, 5,999,822, 6,064,894, 6,069,964, 6,085,113, 6,097,809. Each of these patent documents is hereby incorporated by reference in its entirety for the material contained therein. 
     SUMMARY OF THE INVENTION 
     It is desirable to provide an acoustic decoupling device, that minimizes microphone-speaker interference in a communication device having the microphone in close proximity to the speaker, which has a channel for routing wiring, provides a strain relief and which is composed of materials that are insensitive to both seismic and acoustic vibrations. 
     Therefore, it is an object of this invention to provide a decoupling damping device for use in a communication system that has the microphone and speaker in close proximity, as described and recited in the claims. 
     This and other objects of this invention are achieved by the apparatus herein described and are readily apparent to those of ordinary skill in the art upon review of the following drawings, detailed description and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order to show the manner that the above recited and other advantages and objects of the invention are obtained, a more particular description of the preferred embodiments of this invention, which is illustrated in the appended drawings, is described as follows. The reader should understand that the drawings depict only present preferred and best mode embodiment of the invention, and are not to be considered as limiting in scope. A brief description of the drawings is as follows. 
     FIGS. 1 a  and  1   b  are perspective views of a first present preferred embodiment of this invention. 
     FIGS. 2 a  and  2   b  are perspective break-out drawings showing the first present preferred embodiment of this invention in association with a preferred communication system. 
     FIG. 3 is a perspective view of the assembled system of the first present preferred embodiment of this invention. 
     FIG. 4 is a perspective detail drawing of the first present preferred embodiment of this invention connected to a preferred microphone. 
     FIG. 5 is a perspective detail drawing of the first present preferred embodiment of this invention showing the cable channel and interface to the preferred speaker. 
     FIG. 6 is a perspective detail drawing of a second present preferred embodiment of this invention. 
     FIG. 7 is a perspective detail drawing of a third present preferred embodiment of this invention. 
    
    
     Reference will now be made in detail to the present preferred embodiment of the invention, examples of which are illustrated in the accompanying drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     This invention is an apparatus to dampen interference and feedback from a speaker—microphone pair, which are in close proximity to each other. This invention also provides a routing channel for wiring in a wearable ear set, as well as strain relief. In its present mode, this invention accomplishes seismic vibration control by the careful choice of a semi-rigid (soft) PVC molded overmold part, which absorbs shock waves that tend to travel through the speaker/microphone housing. Also, the use of a semi-rigid, molded part to acoustically isolate the speaker and microphone from each other increases manufacturing yield by minimizing manufacturing variance, thereby increasing communication device quality while reducing manufacturing costs. For the purposes of this disclosure, the terms “cell phone” and “cellular telephone” is to be defined to include any mobile telephone, including but not limited to traditional cellular telephones, PCS telephones, satellite phones, radio phones and wired traditional telephones. 
     As the use of cellular telephones has increased in automobiles a corresponding increase in traffic accident rates has occurred resulting from automobile drivers being distracted from the road and/or traffic conditions by the use of their cell phones. Accordingly, the public and lawmakers are demanding either that hands-free headsets be provided or that cell phone use in vehicles be banned. Hands-free headsets are also increasing in use in the office and home environment. Both computer voice recognition and office productivity requirements are increasing the demand for hands-free telephone headsets. Hands-free headsets have often had certain technical problems, often including feedback and cross-talk between the speaker and the microphone due to the relative close proximity of the speaker to the microphone. Addressing the problem of feedback, crosstalk, vibration and the like has been a long-standing need and priority in the headset communication device industry. This invention addresses this problem by providing a near-field speaker/microphone acoustic and seismic vibration dampening device, thereby increasing the effectuality of hands-free headsets for use with both cellular telephones and standard telephone or computer equipment. 
     FIG. 1 a  shows a perspective view of the front of the first preferred device of this invention. Referred to herein as a first overmold  100 , this device is preferably constructed as a single molded PVC part, although alternative materials, including but not limited to soft plastic, rubber, ceramic, high density foam, and the like may be substituted with reduced performance without departing from the concept of this invention. The construction of this present embodiment is as follows. A stem  101  is fixed to the bottom  102  of the mold  103  to provide cable strain relief. The mold  103  has a cavity portion  105  defined by a generally conically shaped wall  104 . A snap ring attachment portion  106  is provided on the outer surface of the conically shaped wall  104 . 
     FIG. 1 b  shows a perspective view of the rear of the first preferred device of this invention. Besides showing the stem  101 , the mold  103 , the conically shaped wall  104  and the snap portion attachment  106 , this view also shows the microphone recess  107 . The microphone recess  107  is formed in the overmold  100  in order to support the desired microphone  202  (see FIGS. 2 a,    2   b ). At the base  109  of the microphone recess  107  is provided a channel  108  for wiring connection between the microphone  202  and the phone connection wire  201  (see FIGS. 2 a,    2   b ). A second wiring channel  110 , in the rear  111  of the microphone recess  107 , provides for the communication of wiring between the speaker  207  and the phone connection wire  201 . 
     FIG. 2 a  shows a front perspective view of a break-out of the component parts of this first preferred device of this invention. The overmold  100  is shown with the stem  101  connected to the phone connection wire  201 . The snap ring  206  is shown in relation to the snap portion attachment  106 , to which it is attached in the complete assembly  300  (see FIG.  3 ). The speaker assembly  207 , having a speaker grill  208  installed therein, is shown in relation to the snap ring  206 , to which it is attached in the complete assembly  300 . A top shell  204  is provided as a top cover for the microphone  202 , which is also shown in proximity to the microphone recess  107 , where it would be installed in the complete assembly  300 . A microphone grill  205  is shown between a microphone opening  209  in the top shell  204  and the microphone  202 , where the microphone grill  205  would be installed in the complete assembly  300 . Behind, and in the complete assembly  300  forming the rear of the assembly, is shown the bottom shell  203 . The bottom shell  203  is adapted to tightly fit to the overmold  100 , as shown in further detail in FIG. 4, to enclose the microphone  202 . 
     FIG. 2 b  shows a rear perspective view of a break-out of the component parts of this first preferred device of this invention. This view provides another perspective of the components of this invention. Specifically, this view gives additional detail on the preferred interface  210  between the speaker  207  and the snap ring  206 , as well as the wiring channel openings  108 ,  110 . 
     FIG. 3 shows a front perspective view of a fully assembled first embodiment  300  of this invention. The overmold  100  is shown with the snap ring  206  fitted thereto. Fixed to the snap ring  206  is the speaker  207 , with the speaker grill  208  fitted therein. The speaker  207  is held in place to the snap ring  206  by a clip  301 . The top shell  204  along with the bottom shell  203  are fitted to the overmold  100 . The stem  101  is shown between the phone wire connection  201  and the overmold  100 . In this present preferred embodiment of this invention  300  the components are fixed together by friction fit along with the clip  301 . Envisioned alternative means of fixing the components together include, but are not limited to, adhesive, screws, bolt, pins, welds, pressure press and the like. The overmold  100  is typically made of a soft PVC plastic material and the shell components  203 ,  204  are presently made of ABS plastic, although alternative materials such as soft plastic, rubber, ceramic or metal can be substituted without departing from the concept of this invention. The microphone  202  is a standard commercial miniaturized microphone. The speaker  207 , similarly is a standard commercial miniaturized speaker. The snap ring  206  is presently made of ABS plastic, although alternatively it could be made of other synthetic materials, rubber or metal. 
     FIG. 4 shows a perspective detail drawing of the first present preferred embodiment of this invention connected to a preferred microphone. This view shows the routing of wiring  401 ,  402  within the provided channels  108 ,  110 . Wiring  401  provides the electrical connection between the microphone  202  and the telephone connection wiring  201 . The wiring  402  between the speaker  207  (see FIGS. 2 a,    2   b  and  3 ) is shown extending through the opening  110  and into the overmold  100 . The bottom shell  203  connects to rear portion  410  of the overmold  100  by fitting the bottom edge  404  into the first overmold slot  405 . While the top shell  204  connects to the rear portion  410  of the overmold  100  by fitting the rear edge  408  into the second overmold slot  409 , between the rear portion  401  of the overmold  100  and the interior fitting  403  of the overmold  100 . The bottom shell  203  is fitted to the top shell  204  by inserting the top edge  406  into the top slot  407  of the top shell  204 . While these fittings are typically held in place by a friction fit, adhesive, screws, pins, bolts and welds may be substituted or added without departing from the concept of this invention, and should be considered as within the means of fittings. 
     FIG. 5 shows a perspective detail drawing of the first present preferred embodiment of this invention showing the cable channel and interface to the preferred speaker. A mold cavity  503  is provided with a wiring recess  508 , a post recess  507 , a overmold rear portion recess  506 , a overmold recess  505  and a split core pin recess  504 . A split core pin, having a first side  502   a  and a second side  502   b  is provided to fit within the cavity  105  of the overmold  100  and is shown with the speaker wiring  402  carried within. 
     FIG. 6 shows a perspective detail drawing of a second present preferred embodiment of this invention. This second embodiment  600  employs a boom microphone  609  connected via a cable  608  to the overmold inner housing  601 . An overmold outer housing  610 , comprising a rear portion  607  and a top portion  606 , is fixed to the overmold inner housing  601 . As in the first embodiment, shown assembled in FIG. 3, the speaker grill  603  is attached  602  to the snap ring  604 , which is a part of the  605  ABS inner shell. This embodiment  600  makes use of a boom microphone  609  rather than the miniaturized microphone  202  of the first embodiment  300 . 
     FIG. 7 shows a perspective detail drawing of a third present preferred embodiment of this invention. This embodiment  700  uses an “EarBud” speaker/microphone system, with a speaker assembly  703  sized to fit within a user&#39;s ear, connected to a small overmold assembly  704 ,  705 . The overmold post  708  provides the strain relief between the internal wiring (not shown) of the speaker assembly  703  with the external wiring  706 , which electrically connects the speaker  703  to the microphone housing  707 . The microphone housing  707  is provided with a microphone on/off selection button/switch  701 , which permits the user to turn off the microphone  709  during conversation. The telephone cable connection  702  is provided from the microphone  709  and includes both wiring to the microphone  709  and the speaker  703 . 
     The foregoing description is of several example embodiments of the invention as presently envisioned by the inventors and has been presented for the purposes of illustration and description of the best mode of the invention currently known to the inventors. This description is not intended to be exhaustive of all possible embodiments, nor is it intended to limit the invention to the precise form, connections or choice of components described herein. Obvious modifications or variations are possible and are foreseeable in light of the above teachings. These embodiments of the invention were chosen and described to provide illustrations of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated by the inventors. All such modifications and variations are intended to be within the scope of the invention. The scope of the patent protection of this invention should be determined by the appended claims when they are interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.