Abstract:
A voice acquisition system for a vehicle includes an interior rearview mirror assembly. The mirror assembly may include a microphone for receiving audio signals within a cabin of the vehicle and generating an output indicative of these audio signals. The microphone may provide sound capture for a hands free cell phone system, an audio recording system and/or an emergency communication system. The system may include a control that is responsive to the output from the microphone and that distinguishes vocal signals from non-vocal signals present in the output. The microphone may provide sound capture for at least one accessory of the equipped vehicle, and the accessory may be responsive to a vocal signal captured by the microphone. The interior rearview mirror assembly may include at least one accessory, such as an antenna, a video device, a security system status indicator, a tire pressure indicator display and/or a loudspeaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 11/374,347, filed Mar. 13, 2006, now U.S. Pat. No. 7,468,652, which is a continuation of U.S. patent application Ser. No. 10/792,360, filed Mar. 3, 2004, now U.S. Pat. No. 7,012,507, which is a continuation of U.S. patent application Ser. No. 10/270,830, filed Oct. 15, 2002, now U.S. Pat. No. 6,717,524, which is a continuation of U.S. patent application Ser. No. 09/903,336, filed Jul. 11, 2001, now U.S. Pat. No. 6,466,136, which is a continuation of U.S. patent application Ser. No. 09/396,179, filed Sep. 14, 1999, now U.S. Pat. No. 6,278,377, which is a continuation-in-part of U.S. patent application Ser. No. 09/382,720, filed Aug. 25, 1999, now U.S. Pat. No. 6,243,003, which are hereby incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to an indicator for a vehicle accessory and, more particularly, to an indicator for a microphone for use in receiving an audio signal within a vehicle. 
     Many vehicles today use hands-free cellular telephones or other communication devices to avoid problems which may arise when a driver of a vehicle has to hold a telephone while driving the vehicle. These hand-free devices include a microphone to receive an audio signal from within the vehicle. It is known to include directional or polar microphones in these devices, which constrain the area covered by the microphone to an area where voices would typically originate, such as a driver&#39;s head area. In certain applications, these microphones are implemented in an interior rearview mirror, such that the microphone is positioned in front of the driver and at approximately the same level as the head of the driver. However, the location of the mirror may be at a distance which is beyond the optimal operative range of the microphone, due to the forward slant of the windshield away from the driver and the location at which the mirror is mounted thereto. Furthermore, rearview mirrors are adjustable to account for different sized drivers, which may result in the microphone being directed away from the head of the driver or other occupants, and thus receiving other noises from within the cabin of the vehicle. 
     An additional issue with known mirror-mounted microphones (such as interior rearview mirror assemblies with a microphone located within the movable mirror housing and/or the mirror mounting bracket, such as a header mounting bracket) is that typically, audio or communication devices in vehicles are optional. Accordingly, separate mirror housings and wiring bundles or harnesses are required to accommodate the standard mirror and the optional mirror which includes the microphone or other accessories such as a vehicle alarm status indicator. This leads to a proliferation of parts within the vehicle assembly plants, which further results in increased costs to the vehicle. 
     Many vehicles which offer hands-free communication devices mount the microphones in a headliner console rearward of the windshield and along the ceiling of the interior cabin of the vehicle. By mounting the microphones in the headliner console, the microphones may be in a substantially fixed position and directed toward the driver head area within the vehicle. However, this positions the microphone substantially above the driver where it may not optimally pick up the voice signal of the driver, since the driver&#39;s voice is directed generally forwardly while the driver continues to view the roadway, while the microphone is directed generally downwardly from the ceiling. Furthermore, locating the microphones in a headliner console adds to the vehicle costs, due to additional installation processes and more costly parts, such as additional ceiling trim, console components and the like. Also, locating the microphone in a headliner console fails to avoid the requirement of at least two separate headliner consoles to accommodate the optional microphone verses a console without the microphone. 
     An additional issue with communication devices in vehicles is that when the device is in use, the user may not be certain that the message conveyed is properly received by the other party. This may be especially troublesome when the other party is an automated voice system which responds to a particular voice communication. 
     Therefore, there is a need in the art for a microphone which may be mounted generally forwardly of the driver of the vehicle, and fixedly mounted to maintain proper orientation with respect to the driver of the vehicle. 
     SUMMARY OF THE INVENTION 
     The present invention is intended to provide an indicator for a microphone or accessory module, and preferably for an indicator for a microphone mounted in, at or on an interior rearview mirror assembly to comprise part of an interior rearview mirror system. The microphone or accessory module preferably mounts along an upper, inner edge of the windshield of a vehicle to direct the microphone, which is preferably a polar or directional microphone, generally downwardly and rearwardly toward the driver of the vehicle, and most preferably, towards the head of the driver, in order to best pick up vocal communication from the driver&#39;s mouth. The indicator provides an indication signal, preferably a visual indication signal, to the user of the microphone which indicates whether the voice communication from the user is adequately being received and preferably whether the communication is adequately being discriminated from other audible inputs received by the microphone that are non-vocal. Thus, the indicator provides an indication signal that an adequately high vocal signal to audible non-vocal noise discrimination ratio is occurring. The accessory module is adaptable for use on a vehicle with a rearview mirror which is separately mounted on the interior surface of the windshield such as a button mounted rearview mirror, and may further include a wire cover extending downwardly from the module to the mounting button of the rearview mirror. The wire cover functions to cover any mirror wiring harness which may connect the rearview mirror assembly to a vehicle wiring harness, typically within the headliner of the vehicle. 
     According to an aspect of the present invention, an audio system for a vehicle comprises a microphone and an indicator. The vehicle has a cabin and a windshield. The microphone is operable to receive audio signals from within the cabin. The audio signals include vocal signals generated by the human voices of vehicle occupants. The indicator is operable to communicate a receiving status of the audio signals to a user of the audio system and is adapted to indicate to the driver and/or other occupants of the vehicle that a voice generated vocal signal is being appropriately received by the audio system that the microphone feeds, and that the vocal signal is being appropriately and substantially discriminated compared to other audible non-vocal signals picked up by the microphone, such as HVAC noise, wind noise, music and the like. The indicator may communicate a receiving status of the microphone and/or a receiving status of another party remote from the vehicle. Thus, the indicator operates to confirm to the driver that verbal inputs/commands/messages/sentences, as spoken by the driver have been received at the microphone and processed by the audio system with sufficient clarity and volume, such that the verbal inputs/commands/messages/sentences have been adequately correctly received. This is of particular importance when the driver and/or occupants of the vehicle are communicating via the microphone/audio system in the vehicle via radio transmission to a receiver remote from the vehicle. Such remote receivers can provide a variety of services that are selected by and/or are dependent on clear and audible voice input received from the vehicular audio system. For example, a concierge-type service can be provided, whereby a restaurant, address, etc., listing can be provided. Also, the vehicle occupant may be voice communicating with an automatic computer based service, such as airline reservation services and the like, where the driver must select menu items through verbal input of an alphanumeric (typically a number) input. Lack of clarity and/or volume and/or the presence of noise may lead to an incorrect selection at the remote receiving party, unbeknownst to the vehicle based driver and/or occupant. The indicator of the present invention thus provides to the driver and/or occupants of the vehicle an indication that verbal input to the audio system in the vehicle is being adequately correctly received by the audio system in the vehicle and/or, more preferably, is being adequately received after transmission to the remote receiver. Thus, by having an adequately clear reception by the remote receiver external to the vehicle confirmed back to the vehicular audio system, and by having this indicated to the driver and/or other occupants by the indicator of the present invention, protection is provided against inadequate communication, even caused by interference during the transmission from the vehicle to the remote receiver or receiving party. 
     According to another aspect of the present invention, an accessory module comprises at least one microphone for receiving audio signals from within a cabin of a vehicle, at least one indicator, and a housing for mounting the microphone. The vehicle includes a windshield, an interior rearview mirror mounted to an interior surface of the windshield, and a headliner extending along an upper edge of the windshield. The indicator is operable to communicate a receiving status of the audio signals to a user of the audio system. The housing for the microphone is preferably mountable between the headliner and the rearview mirror. The microphone and indicator of the accessory module (and any other accessory housed within the accessory module) are electronically connectable to a vehicle wiring within the headliner. Preferably, accessories, such as the microphone and the indicator, are detachably connectable to the vehicle wiring, such as by a plug and socket connector (for example, a multi-pin electrical plug and socket connector system), so that the module can be optionally installed to the vehicle with ease. This is particularly advantageous in circumstances when the interior mirror is a non-electrical mirror, such as a base prismatic mirror. 
     In one form, the rearview mirror is electronically connected to the vehicle wiring harness. Preferably, the accessory module further includes a wire cover to encase a wire harness between the rearview mirror and the accessory module. More preferably, the microphone, indicator and mirror are connectable with the vehicle wiring in the headliner. 
     According to another aspect of the present invention, an accessory module for a vehicle comprises at least one microphone for receiving audio signals from within a cabin of the vehicle, a microphone housing for mounting the microphone, and an interior rearview mirror assembly. The vehicle includes a windshield and a headliner extending along an upper, inner edge of the windshield. The microphone is electronically connectable to a vehicle wiring harness within the headliner. The microphone housing is mountable to the windshield adjacent to the headliner. The mirror assembly includes a mirror wire harness and a mirror housing. The mirror wire harness is electronically connectable to the vehicle wiring harness in the headliner. An indicator may be provided for the audio system to communicate an audio signal receiving status to a user of the audio system. 
     In one form, the mirror assembly further includes a mounting button for mounting the mirror assembly to an interior surface of the windshield. The mounting button may be interconnected to the microphone housing via a wire cover extending between the microphone housing and the mounting button and at least partially encasing the mirror wire harness and/or the mounting button itself. The indicator may be mounted on at least one of the accessory module, the mirror housing, a module/pod attached to the mounting button, and the mounting button. 
     In another form, the microphone housing includes a mirror mounting arm which extends generally downwardly therefrom. The mirror housing is pivotally interconnected to a lower end of the mounting arm. The mirror wire harness is at least partially encased within the mounting arm. 
     Accordingly, the present invention provides an indicator for a microphone or accessory module for use with an audio system, such as a hands-free cellular telephone, audio recording device, emergency communication device or the like. The indicator provides a signal to a user of the audio system which communicates whether a human vocal audio signal being received by the audio system is above a threshold level and/or is at least substantially discriminated from other audible noise, so that the vocal signal to non-vocal audible signals received by the audio system from the microphone exceeds a predetermined threshold ratio. Preferably, this ratio is at least 2:1. Most preferably, this ratio is at least 10:1. The microphone and indicator may be mounted in the vehicle cabin, and preferably is mounted as part of the interior rearview mirror system. The accessory module may contain the microphone and/or the indicator and is preferably mounted above the mirror between the mirror and the headliner of the vehicle, which provides a fixed location of the microphone for maintaining proper orientation of the microphone with respect to the vehicle interior. The indicator may be mounted at the accessory module, a rearview mirror housing, behind the mirror reflector in the housing so as to illuminate through the reflector, a rearview mirror mounting portion or a headliner of the vehicle. Because the accessory module is a separate component from the mirror and headliner, additional mirror or headliner console components for mounting the microphone are not required. The present invention facilitates fewer parts in the assembly plant since the headliner and mirror assembly may be the same part regardless of whether the audio or communication device associated with the invention is to be installed within the vehicle. Furthermore, because the accessory module does not require special headliners or mirrors, the accessory module may be easily installed as an aftermarket device. 
     These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the microphone module of the present invention; 
         FIG. 2  is a side elevation shown partially in section of the microphone module in  FIG. 1 ; 
         FIG. 3  is a similar side elevation as that in  FIG. 2 , showing an alternate electrical connection and mounting bracket for the microphone module; 
         FIG. 4  is a sectional plan view of the microphone module taken along the line IV-IV in  FIG. 3 ; 
         FIG. 5  is a similar side elevation as that in  FIG. 2 , showing a microphone module without a wire cover but including a self-coiling wire harness; 
         FIG. 6  is an elevation looking forwardly in a vehicle cabin of a microphone module and mirror housing having controls mounted thereon; 
         FIG. 7  is a side elevation shown partially in section of a microphone module and mirror housing having various electrical and/or electronic components therein; 
         FIG. 8  is a similar side elevation as that in  FIG. 2  of an alternate embodiment of the present invention, having a rearview mirror mounted to an arm extending downwardly from the microphone module; and 
         FIG. 9  is a perspective view of an interior rearview mirror incorporating the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now specifically to the drawings, and the illustrative embodiments depicted therein, an accessory or microphone module  10  is mounted adjacent to a vehicle windshield  12 , as shown in  FIG. 1 . Microphone module  10  may be implemented in the vehicle in association with an audio system, such as a cellular telephone, a recording device, such as a dictation system, an emergency communication device, such as the ONSTAR system commercially available in certain General Motors vehicles, or any other audio device which may include a microphone or audio receiving device. Preferably, the manually actuated buttons to operate the ONSTAR system are mounted at a movable housing  16   b  of an interior rear view mirror assembly  16 , such as is shown generally at  13  in  FIG. 1 . The vehicle includes a headliner  14 , which at least partially covers the ceiling of an interior passenger compartment of the vehicle and has a forward edge  14   a  which interfaces with an upper edge  12   a  of windshield  12 . An interior rearview mirror assembly  16  may be mounted to an interior surface  12   b  of windshield  12 , typically at a position spaced downwardly from upper edge  12   a  and the position of module  10 . Microphone module  10  includes at least one microphone  18  which is fixedly secured within a microphone housing  20  and is directed toward an area generally defined by the location of a head of a typical driver of the vehicle. An indicator  72  is included for providing an audio signal receiving status message to a user of the audio system. The message conveys to the user whether the audio signal was adequately received by the microphone  18  and/or a receiving party of the audio system which is remote from the vehicle. The audio system of the vehicle, such as the ONSTAR vehicle system, communicates with the receiving party, typically via a satellite transmission of radio frequencies or via a terrestrial radio frequency transmission system involving multiple receivers, transmitters, and/or repeaters. Microphone module  10  may further include a wire cover  22  which extends downwardly between housing  20  and mirror assembly  16  to encase or cover a mirror wire harness  24 , which may be included in mirror assembly  16  to provide power or control signals to components or accessories which may be mounted within or associated with mirror assembly  16 . 
     As shown in  FIG. 2 , mirror assembly  16  may include a conventional mounting button  16   a  and a mirror housing  16   b  supporting a prismatic, electro-optic or electrochromic reflective element  16   d . Mounting button  16   a  may be adhesively secured to interior surface  12   b  of windshield  12  at a location substantially below forward edge  14   a  of headliner  14  and upper edge  12   a  of windshield  12 , as is known in the art. Mirror housing  16   b  is pivotally mounted to mounting button  16   a  via an arm  16   c , which is pivotally interconnected to button  16   a  or housing  16   b , or both, such that housing  16   b  is pivotally adjustable about mounting arm  16   c . Alternately, mounting arm  16   c  terminates at the vehicle headliner to pivotally mount the mirror assembly to the headliner of the vehicle. Mirror housing  16   b  encases a reflector  16   d  ( FIG. 7 ) for reflecting an image of a scene generally rearwardly of the vehicle to the driver (and with the mirror housing being adjustable by the driver), and a bezel  16   e  which retains reflector  16   d  in housing  16   b , as is well known in the art. Mirror wire harness  24  extends generally upwardly from mirror housing  16   b  to headliner  14  for electrical connection with a vehicle wiring harness  28  ( FIG. 3 ). Mirror wire harness  24  provides electrical power and/or control signals to the mirror assembly  16  or various mirror mounted accessories within assembly  16 , such as power for electro-optic/electrochromic mirrors, interior lights (such as map lights in the mirror housing), and displays such as for compass headings, temperatures, passenger airbag status, or the like. 
     Headliner  14  extends along upper edge  12   a  of windshield  12  and may be a plastic trim panel to secure a fabric ceiling cover and provide an aesthetically pleasing finish between the windshield and the fabric ceiling cover of the vehicle. Alternately, headliner  14  may be a forward portion of the fabric cover or a ceiling console. Headliner  14  may further include other trim or headliner console components (not shown), for storing various articles, such as sunglasses, garage door openers or the like or for housing other components or accessories associated with the vehicle. 
     Indicator  72  is operable with microphone  18  and the audio system to provide a signal to a user of the audio system, typically the driver of the vehicle, which conveys a level of reception of the user&#39;s vocal signal by the audio system. Indicator  72  may be used with microphone  18  as part of an interior rearview mirror system. The interior rearview mirror system may comprise a reflective element positioned in a mirror housing  16   b . The housing  16   b  may be pivotally mounted to a mounting arm  16   c  which terminates at a mirror mount, such as at a mounting button or the like secured to the windshield and/or a mount at a header of the vehicle. The mirror system may include pods, gondolas, modules, or the like, attached to one or more of the housing, arm and mount. The mirror system may further include a wire cover and/or any microphone and/or accessory module. The mirror system may further include indicator  72 , microphone  18  and/or other vehicle accessories mounted at, on or in the mirror assembly  16 , such as at housing  16   b , mounting arm  16   c , mounting button  16   a , or a pod or module attached thereto. Indicator  72  and microphone  18  and/or other accessories may otherwise be mounted at accessory module  10 , without affecting the scope of the present invention. 
     Preferably, indicator  72  provides a receiving status signal in response to a reception of the audio signal by the audio system reaching a threshold level of clarity and/or volume. The signal may communicate the reception status of the microphone, so as to alert the driver to speak up or speak more clearly. Preferably, the indicator signal indicates when a human voice signal is being adequately received by the microphone. Alternately, or in addition to the reception status of the microphone, the indicator signal may communicate the reception status of a receiving party of the communication which is remote from the vehicle, such as another party&#39;s cellular phone or the ONSTAR receiving station. For example, the indicator may be connected to a control (not shown) of the audio system and may receive a signal from the receiving party external to the vehicle, such as from the receiving station of the ONSTAR system, which indicates whether the message sent by the user in the vehicle was adequately received by the ONSTAR system. 
     Preferably, indicator  72  is operable with a control (not shown) which discriminates between vocal signals and other audible inputs received by microphone  18  which are non-vocal. The indicator  72  thus provides a signal that an adequately high voice signal to audible noise discrimination ratio is occurring. The indicator may indicate when an audible signal received by the audio system is above a threshold level. Preferably, the indicator indicates when the audible signal is a vocal signal which is discriminated from other audible noise, such as HVAC noise, wind noise, music and the like, so the vocal signal to non-vocal signal received by the audio system is at or above a predetermined threshold ratio. Preferably, this ratio is at least approximately 2:1. Most preferably, this ratio is at least approximately 10:1. 
     Preferably, indicator  72  provides a visual indication of the quality of the reception of the audio signals. Preferably, indicator  72  is a solid state light emitter such as a light emitting diode (LED), is a phosphorescent element or display or is a tell-tale, such as an LED backlit icon. However, indicator  72  may be an incandescent bulb, an incandescent backlit tell-tale, or any other illumination source, without affecting the scope of the present invention. The indicator may then display when the microphone and/or audio system is receiving and distinguishing or discriminating a good signal. For example, if the signal is adequately received, indicator  72  may be activated to provide an illumination signal to the driver, and if the signal is poor or is breaking up between the vehicle and the receiving end of the communication, the indicator may be deactivated or flashed to alert the user. Indicator  72  may also be operable as another signaling device when the audio system is not in use or is over ridden when it is desired to display the status of another vehicle function. For example, indicator  72  may provide a security system status indication (discussed below) or a status of other operable systems or controls within the vehicle. Preferably, indicator  72  would provide a status indication of a system or control which is not typically activated when the audio system would be in use, such as the security system, which is typically activated when a driver leaves the vehicle. Preferably, the intensity of indicator  72  is modulated dependent upon the vehicle cabin ambient light level. Thus, for example, the indicator intensity is decreased during night time driving conditions to better suit the then darkened cabin lighting environment. This can be achieved such as by use of a photo-detector (such as the ambient and/or glare photodetector commonly used in electrochromic (EC) automatic dimming interior rearview mirror assemblies) or may be tied to the vehicle lighting instrument panel system so that the intensity of indicator  72  dims in tandem with the dimming of, for example, the instrument panel displays. 
     It is further envisioned that the indicator  72  may include multiple light emitters  72   a ,  72   b ,  72   c ,  72   d , and  72   e , as shown in  FIG. 9 . The number of indicators illuminated would then provide an estimate to the user of the strength and/or quality of the audio signal being communicated. For example, if the signal is very strong or clear, all of the multiple light emitters may be illuminated, while if the signal is weak, some number of emitters less than all will be activated, depending on the strength or quality of the signal. Each emitter would be activated in response to a different threshold level of signal quality being received by the audio system. 
     Although indicator  72  is preferably one or more illumination sources, indicator  72  may alternately be an audible source, such as a loudspeaker or the like, which may provide an audio signal to the user of the audio system to alert the user when the signal quality drops below a threshold level of acceptability. The audible source may provide an audible tone when the signal quality deteriorates, or may include a voice chip, such as a digital recording of a human voice message contained on a semi-conductor chip, to tell the user of the system to speak up, repeat the message or speak more clearly. It is further envisioned that the indicator  72  may provide an alphanumeric display, which may provide a printed message or digital rating of signal quality to the user of the audio system. Each message displayed or number in a rating scale would correspond to a different threshold level of signal quality, such as clarity and/or volume. 
     Indicator  72  and microphone  18  may be connected to a control (not shown) which monitors the audio signals received by microphone  18 . The control may be operable to discriminate between different audio signals, such as between voice signals and non-voice signals, such as music, fan noise, and wind noise. The control may be further operable to provide a message via indicator  72  to alert the user of the audio system to turn down a radio in the vehicle, turn down or off a blower for a heating, ventilation and air conditioning system, roll up the windows of the vehicle, and/or adjust other sources of non-voice signals within the vehicle, such as turn signals or the like, in response to a detection of one or more of these non-voice signals. Alternately, or in addition thereto, the control may further be operable to automatically adjust the volume of the radio, the fan speed of the blower, the window setting and the like in response to such a detection. The control and indicator may also alert the user of the system if multiple voices are being received simultaneously, such as via conversations between passengers in the vehicle or conversations on the radio, which may detract from the clarity of the signal being received by the microphone. 
     The audio system and microphone may further include a learning mode, whereby the audio system/microphone combination learns the vocal characteristics of a particular driver or occupant, so that the ratio of vocal signals to non-vocal noise signals received by the system can be enhanced. The learning mode may be operable in a memory system, such as is known in the automotive art, whereby a group of drivers and/or occupants, typically one, two or three individuals, may be recognizable by the audio system. The learning mode may be operable to recognize a particular individual&#39;s voice via the operator selecting the learning mode and speaking a brief message to the microphone. The audio system then receives the individual&#39;s voice message and repeats the message back to the individual via a speaker or alphanumeric display. This process is continued until the message is accurately recognized and repeated by the audio system. The recognized vocal characteristics may then be stored to memory for future use by the individual. A security feature for the audio system and/or any vehicle accessory and/or the vehicle itself can be provided via voice recognition. 
     Preferably, indicator  72  is mounted at, in or on the mirror housing  16   b , either at, within or on or adjacent the bezel  16   e . This is preferred because the driver of the vehicle is typically the person using the audio system, and this location provides optimal visibility of the indicator to the driver, since the mirror housing is adjusted to be directed toward the driver. Indicator  72  may otherwise be mounted in the housing  16   b  and behind the mirror reflector  16   d , so as to illuminate through the reflector. However, as shown in the Figures, indicator  72  may alternately be positioned at accessory module  10 , mirror mounting portion  16   a , or headliner  14 , and may be positioned at any other location where the indicator is visible to the user of the audio system, without affecting the scope of the present invention. It is further envisioned that indicator  72  may be implemented with a microphone  18  which is mounted at mirror housing  16   b  or mirror mounting portion  16   a , as shown in  FIGS. 2 ,  3 ,  7  and  9 , in applications without an accessory module. As shown in  FIG. 2 , microphone  18  and indicator  72  may alternately be positioned at a pod  17 , which may be attached to mounting portion  16   a , arm  16   c , or housing  16   b  of mirror assembly  16 . A speaker  42  may also be included with microphone  18  and indicator  72 , in applications either with or without accessory module. 
     By providing an indication of the receiving status of vocal signals received by the audio system, the present invention significantly reduces the possibility that a message will not be received clearly, correctly, and/or accurately by the receiving party. The vehicle based user of the audio system is alerted immediately if the microphone is not adequately receiving and/or is not adequately/correctly/accurately interpreting the message and/or if the other party to the communication is not adequately receiving the message. Accordingly, the user may speak up or speak more clearly, or adjust the volume of other noises or conversations within the vehicle to correct the reception concerns. The user may also re-send the message if it was not properly being received by the other party. The present invention is especially useful when the other party is an automatic or computer based voice recognition system. The user in the vehicle will be alerted by indicator  72  that the message sent may not have been properly received by the voice system and may then re-send the message or try again later in order to ensure that the message is properly received. 
     The audio system is connected to indicator  72  and microphone  18 . Microphone  18  may share its audio receiving function with a plurality of audio systems, such as a cellular phone, the ONSTAR system, a recording device, such as a digital recording device, and/or other systems which receive audio signals. Preferably, a digital recording device is incorporated in the interior rearview mirror system, such as within the interior rearview mirror housing. One or more functions may be selected at one time. For example, if the microphone is being used with a cellular phone function, it may also be used to provide an input to the recording device. The function of microphone may be manually selected by controls, such as switches or buttons, within the cabin of the vehicle or may be voice selected and controlled. Microphone  18  and the audio system may also be voice activated to further ease the operation of the audio system. This is preferred because it may be difficult to manually activate and control the audio system while driving the vehicle. Also, voice activation of the system substantially precludes the likelihood of leaving the system on when it is not in use, which would drain the vehicle&#39;s battery over time, since the audio system would be automatically deactivated when voices are not received by the microphone. Microphone  18  may also function as a receiver for one or more other vehicular functions and controls, such as voice activated headlamps, alarm systems, radios, cruise control, windows, cellular phones, message recorders, pagers, back up aids, windshield wipers, rain sensors and the like. 
     Optionally, the interior rearview mirror system can include a display of the status of the vehicle tire inflation (such status can be provided by monitoring the ABS braking system and/or by individual tire pressure sensors in the individual vehicle tires). The interior rearview mirror system may also include a PSIR (passenger side inflatable restraint) display for indicating the status of a PSIR. The tire inflation display, the PSIR display or other displays indicating the status of vehicular accessories or functions may be provided at the interior rearview mirror assembly, such as at, on or in the mirror housing, mounting arm, mounting button, or pod/module attached to the housing, arm or mounting button. 
     The interior rearview mirror system may further include a camera and/or display, for providing an image of an area not viewable by the rearview mirror when it is adjusted for driving conditions. Preferably, the camera may be directed toward the rear seats of the vehicle so as to function as a child minder. The portion of the vehicle being viewed by the camera (preferably a CCD and, most preferably, a solid state CMOS camera) is preferably illuminated. Preferably, the video camera selected, such as a CMOS camera, is sensitive in the near-infrared region and so has night vision capability. Most preferably, the illumination is provided (preferably, mounted at and illuminating from the mounting site of the camera itself) by one or more near-infrared illumination sources, such as light emitting diodes which emit efficiently in the near-infrared portion (wavelengths from approximately 0.75 microns to about 1.5 microns), but which do not emit efficiently in the visible portion (wavelengths below approximately 0.75 microns) of the electromagnetic spectrum. Therefore, the interior cabin of the vehicle may be illuminated with radiation in a range which the camera is sensitive to, such that the system can form a clear image of the area on the display, while the cabin is not illuminated with visible light which, at night, may be sufficient to cause glare or discomfort to the driver and/or passengers in the illuminated area. 
     Although the mirror system and/or vehicle is described above as including one or more of a camera, pager system, cellular phone and the like, it is further envisioned that these accessories and others may be portable or dockable with a connecting port of the vehicle or mirror system. An individual or driver of the vehicle may use the personal pager, cellular phone, video camera, electronic personal organizers, such as a PILOT unit or the like, remote from the vehicle, such as at home, in a business office, or the like, and may then dock, plug in or otherwise connect the device to the connecting port for use within the vehicle. The devices may be dockable at the interior rearview mirror assembly, or may be dockable elsewhere in the vehicle, without affecting the scope of the present invention. The dockable device may, when docked into the vehicle, may personalize the controls and functions of the vehicle to suit that individual driver. Thus, features such as seat position, radio station selection, mirror field of view orientation, climate control, and other similar vehicle functions may be set to suit the individual preferences, or restrictions (such as a restriction from use of a cellular phone, or the like) for that particular driver. Such dockable portable devices may be especially useful to provide a security function and/or for tracking, logging, accounting for individual users, such as would be desirable for fleet operators, car rental operators, school bus fleet operators, and the like. 
     Microphone  18  may be mounted to accessory module  10 , which includes wire cover  22  ( FIGS. 1 and 2 ) which extends between a lower edge  20   c  of housing  20  and mounting button  16   a  of mirror  16 . Mirror harness  24  is encased within wire cover  22  to retain harness  24  and provide a finished appearance to the electrical connection of mirror  16  to vehicle wiring harness  28 . Preferably, wire cover  22  is telescopingly extendable and retractable to adapt the length to different mounting locations of mounting button  16   a  relative to headliner  14  on various vehicles. As best shown in  FIG. 2 , wire cover  22  may extend or retract by sliding upwardly or downwardly within housing  20 . This facilitates implementation of microphone module  10  in various vehicles and further facilitates the aftermarket installation of module  10  in vehicles having a button-mounted interior rearview mirror. 
     Microphone module  10  is preferably secured to interior surface  12   b  of windshield  12  at an interface junction  26  between forward edge  14   a  of headliner  14  and interior surface  12   a  of windshield  12 . However, it is envisioned that microphone module  10  may be mounted in other locations. Housing  20  of microphone module  10  is preferably formed with a substantially flat windshield mounting surface  20   a  and a curved, concave headliner surface  20   b , such that housing  20  mounts to windshield  12  along mounting surface  20   a , while headliner surface  20   b  substantially uniformly engages headliner  14  to provide a flush, finished transition between microphone module  10  and headliner  14 . Preferably, housing  20  is adhesively secured to interior surface  12   b  of windshield  12 , such as by bonding, pressuring sensitive adhesives, anaerobic adhesives, double faced tape, or the like. However, microphone module  10  may optionally be mechanically secured to an intermediate mounting bracket adhered to the windshield, or may be connected to the headliner itself, as discussed below, without affecting the scope of the present invention. Microphone module  10  is preferably a plastic molded part, which facilitates forming the part in various shapes to match the headliner/windshield interface and to further facilitate providing the part in different colors to match optional interior colors of the vehicles. 
     Mirror harness  24  may connect directly to vehicle wiring  28  while an accessory wiring harness  30  may separately connect to the vehicle wiring to provide power and/or control signals to the accessories within accessory module  10 . Alternately, mirror harness  24  may connect to module  10 , which may then be connectable to vehicle wiring  28 , as shown in  FIGS. 3 and 7 . Because microphone module  10  may be a separate module from the headliner and the mirror assembly, and because module  10  is preferably connected to the vehicle wiring independent of wires from the interior rear view mirror assembly to the vehicle wiring, microphone module  10  may be easily removed or accessed for serviceability or replacement without having to remove or replace the mirror assembly. This is a significant advantage over the prior art because if the microphone is damaged, the more expensive components, such as the mirror or headliner console, do not have to be replaced in order to repair or replace the microphone. 
     Microphone module  10  may be mounted to windshield  12  such that microphone  18  is directed downwardly and rearwardly toward the driver&#39;s seat of the vehicle to optimally receive audio signals therefrom. Preferably, microphone  18  is a directional or polar microphone, which limits the audio signal received to signals within the area toward which the microphone is directed. Such microphones are known in the art and are commercially available as an AKG 400 Series or a 501T Series microphone from A.K.G. Acoustics/GMBH in Vienna, Austria. These microphones are operable to receive audio signals from within the targeted area, while substantially reducing or limiting the signals received from outside that area. By mounting microphone  18  within housing  20  and directing microphone  18  downward and rearward toward a typical location of a driver&#39;s head, the audio signal detected by microphone  18  will be dominated by a voice signal from the driver of the vehicle and will substantially limit noise signals originating from other sources, such as the engine, road, wind, HVAC, radio, turn signals and the like. Because microphone  18  may be fixedly mounted within housing  20 , microphone  18  may be optimally directed toward the area of interest, and will not be adjusted or misdirected when the mirror is adjusted for a different driver of the vehicle. 
     Alternately, multiple microphones may be implemented within microphone module  10  to receive various signals from different directions. As is known in the audio art, RMF techniques may be implemented to digitize individual outputs from the multiple microphones and integrate the outputs to establish which outputs are the loudest and which have the presence of human audible signals verses noise. The signals which have the greatest presence of human audible signals may then be selected over the signals of the other microphones, thereby providing a voice signal to the communication device. 
     Microphone module  10  further includes a microphone wire harness  30  ( FIG. 3 ), which extends from microphone  18  through headliner surface  20   b  of housing  20  and into headliner  14 . Microphone  18  is preferably interconnectable to the vehicle harness by microphone harness  30  in a conventional manner. Preferably, microphone harness  30  comprises a pair of wires for microphone  18 . Clearly, however, if multiple microphones are implemented in microphone module  10 , multiple wires (not shown) will correspondingly be required. Furthermore, if indicator  72  is included in module  10 , additional wiring  30   a  ( FIG. 4 ) will also be required. 
     As shown in  FIG. 2 , the audio system may further include a loud speaker  42  for providing an audible signal to the driver and passengers of the vehicle. Speaker  42  may be mounted to housing  20  and includes a wiring harness  43  for electrical connection to the vehicle wiring  28 , similar to microphone  18 . Speaker  42  may be a conventional diaphragm speaker, piezo-electric speaker, such as a piezo-electric ceramic speaker, or the like. Most preferably, speaker  42  is a piezo-electric ceramic moldable speaker. Additional speakers may be mounted within the accessory module  10  or in a pod  17  attached to the mirror mounting bracket  16   a  of the interior rear view mirror assembly. 
     It is further envisioned that the audio system may include multiple microphones and/or speakers positioned at different locations within the vehicle to supplement one another in order to optimally receive and project the audio signals from and to the desired areas within the vehicle. For example, as shown in  FIG. 2 , one or more microphones  18  and/or speakers  42  may be positioned in module  10 , as well as in mirror housing  16   b , in mounting button  16   a , and/or within a pod  17 , which may be mounted to mirror assembly  16  and extends downwardly beneath mirror housing  16   b . Clearly, pod  17  may alternately be positioned above or to either side of mirror housing  16   b , without affecting the scope of the present invention. The microphone  18  and speaker  42  may access and/or share the electronic circuitry of an electro-optic or electrochromic mirror. By providing one or more microphones and speakers within the vehicle, the overall effectiveness of the audio system may be improved, since signals not optimally directed toward the microphone within the module, may be better received by the microphone in the pod, mirror housing, or button. It is further envisioned that one or more indicators  72  may be positioned at one or more locations within the vehicle, such as at the module  10 , mirror housing  16   b , mounting button  16   a , and/or pod  17 , as shown in  FIG. 2 . Microphone  18  and/or speaker  42  may also be positioned at the mirror or pod assemblies in conjunction with microphones or speakers in a module  10  or in applications where the vehicle does not include a microphone module. 
     Although shown as having a microphone  18  within a module  10 , the present invention includes implementation of a microphone  18  and indicator  72  in various locations within the cabin of the vehicle. As shown in  FIG. 9 , microphone  18  and indicator  72  may be mounted to mirror housing  16   b . Alternately, microphone  18  and/or indicator  72  may be mounted to the mirror mounting button  16   a  or at a pod or other mounting device positioned in the vicinity of the mirror assembly  16 . If the audio system includes a speaker and/or a recording device, the speaker and/or recording device may be mounted to the mirror assembly or pod, or may be positioned elsewhere within the cabin of the vehicle, either in the vicinity of the microphone and/or the indicator or remote therefrom. 
     Referring again to  FIG. 3 , microphone module  10  may alternately connect to the vehicle wiring harness  28  via electrical connectors  32  and  33 . For example, a socket  33  may be provided in housing  20  of microphone module  10 , such that vehicle wiring harness  28  may include a corresponding male connector, such as a conventional twelve pin connector, which mates with socket  33 . Microphone harness  30  may then extend from socket  33  to microphone  18 , while remaining within housing  20 . Similarly, mirror harness  24  may extend from socket  33  downwardly through housing  20  and wire cover  22  to mirror assembly  16 . By connecting both the mirror harness  24  and microphone harness  30  to the vehicle harness  28  with connectors  32  and  33 , microphone module  10  further facilitates simplified installation of mirror assembly  16  within the vehicle. 
     As shown in  FIGS. 3 and 4 , microphone module  10  may be mechanically secured to window  12  and/or headliner  14 . For example, a bracket  34  may be bonded or otherwise adhesively secured to interior surface  12   d  of windshield  12 . Window surface  20   a  of housing  20  may then be correspondingly formed with bracket  34  to engage the bracket for removable mounting of microphone module  10  to windshield  12 . As best shown in  FIG. 4 , bracket  34  may include a windshield mounting surface  34   a  and a pair of mounting flanges  34   b  which are offset from the position of mounting surface  34   a  and extend laterally outwardly from a pair of sidewalls  34   c , which extend downwardly and rearwardly from mounting portion  34   a . Windshield surface  20   a  of housing  20  may then be correspondingly formed to slidably engage mounting flanges  34   b  of bracket  34 , such that housing  20  is slidable upwardly along bracket  34  until headliner surface  20   b  interfaces with headliner  14 . At that point, one or more mounting pins or fasteners  36  may be inserted through housing  20  and mounting flanges  34   b  to substantially secure the components together. Alternatively, or in addition to fasteners  36 , a headliner fastener  38  ( FIG. 3 ) may extend through headliner surface  20   b  of housing  20  and engage a bracket  40  within headliner  14 , thereby substantially securing housing  20  to both windshield  12  and headliner  14 . Mounting fasteners  36  and  38  may be threaded fasteners or push-pin or snap fit type fasteners, to substantially secure housing  20  to the respective brackets  34  and  40 . It is further envisioned that the mounting bracket and microphone housing may be correspondingly formed to press-fit together or snap or otherwise lock together as the microphone housing is moved to the appropriate mounting location relative to the bracket. Clearly, other mounting brackets and/or fasteners may be implemented to substantially secure microphone module  10  relative to windshield  12  or headliner  14 , without affecting the scope of the present invention. 
     Referring now to  FIG. 5 , microphone module  10  may be implemented without a wire cover. The mirror wiring harness may extend freely downwardly from microphone housing  20  to mirror housing  16   b  or may be adhered or otherwise secured or guided along interior surface  12   b  of windshield  12  and further along arm  16   c  to mirror housing  16   b . Alternately, as shown in  FIG. 5 , a mirror harness  24 ′ may be implemented to provide an aesthetically pleasing spirally-coiled cord, similar to a conventional telephone cord, which extends downwardly from lower end  20   c  of housing  20  and curves rearwardly toward housing  16   b  of mirror assembly  16 . Mirror harness  24 ′ may be electronically connectable with vehicle wiring harness  28  via conventional electrical connectors  32 ′ and  33 ′, while microphone harness  30  is electronically connected with the vehicle wiring harness separately, as discussed above with reference to  FIG. 2 . Clearly, however, mirror harness  24 ′ and microphone harness  30  may be connectable to vehicle wiring harness  28  by any other conventional means, without affecting the scope of the present invention. As discussed above with reference to  FIGS. 2 and 3 , housing  20  may be bonded to, adhesively secured or mechanically fastened to interior surface  12   b  of windshield  12  and/or to headliner  14 . 
     Although specific embodiments of the microphone module of the present invention are shown in  FIGS. 2 through 5  and discussed above, clearly the scope of the present invention includes other means of mounting the microphone module and of covering or guiding the mirror harness between the microphone module and the mirror. For example, the microphone module may be mounted to the windshield between mounting button  16   a  and headliner  14  and have wire covers or the like extending from both upper and lower ends of the module to cover wires between the headliner and the module and further between the module and the mirror assembly. Alternatively, the microphone module may be mounted above and adjacent to the mirror mounting button  16   a  and include a wire cover which extends upwardly therefrom to substantially encase the wires extending from the module to the headliner for connection with the vehicle wiring harness. It is further envisioned that the microphone module may be part of a plastic wire cover extending upwardly from the interior rear view mirror assembly toward the headliner. The wiring harnesses associated with the mirror assembly, the microphone and the indicator may be routed and connected with the vehicle wiring harness by any known means without effecting the scope of the present invention. The microphone, indicator and mirror assembly may be implemented as a single component, which requires fewer assembly plant installation processes, thereby reducing the costs associated with the vehicle manufacture. It is further envisioned that microphone  18  and indicator  72  may be mounted anywhere within the cabin of the vehicle without an accessory module. Preferably, both are positioned forwardly of the driver of the vehicle to optimally receive a voice signal from the driver and to be easily viewed by the driver while looking forwardly. Preferably, the microphone and indicator are mounted at the rearview mirror housing  16   b , the mirror button  16   a , the headliner  14 , and/or a pod attached to the mirror assembly (such as a pod attached to the mirror button mount of the interior rearview mirror assembly), windshield or headliner. 
     Although shown and described above as being implemented with a button mounted interior rearview mirror assembly, an alternate embodiment of the present invention may incorporate a mirror assembly  116  with a microphone module  110 , as shown in  FIG. 8 . Microphone module  110  preferably includes a microphone  118  and a microphone housing  120 , which are substantially similar to microphone  18  and housing  20 , discussed above with respect to microphone module  10 . However, microphone module  110  further includes a mirror mounting arm  122 , which extends generally downwardly from a lower portion  120   c  of housing  120 . Mirror assembly  116  is pivotally mounted to a lower end  122   a  of arm  122  via a conventional ball and socket connection  116   a . A mirror wiring harness  124  extends from mirror assembly  116  upwardly through arm  122  and further through housing  120  and into header  14  of the vehicle for electrical connection with the vehicle wiring harness. A microphone harness  130  may also electronically connect microphone  118  with the vehicle wiring harness, as discussed above with respect to microphone harness  30 . Microphone module  110  and mirror assembly  116  may be electronically connected to the vehicle wiring harness by any known means, without affecting the scope of the present invention. An indicator  172  may be included at module  110  and/or at mirror housing  116  to provide an audio signal receiving status to the driver of the vehicle or user of the audio system, similar to indicator  72 , discussed above. Similar to microphone module  10 , a windshield surface  120   a  of housing  120  may be adhesively or mechanically secured along an interior surface  12   b  of windshield  12 . 
     As shown in  FIG. 6 , microphone module  10  may further include manual controls for the audio or communication device associated with microphone  18 , such as buttons  44  for activating and/or adjusting the communication device. Microphone module  10  may further include other manual controls  46  for activating or adjusting other accessories or devices within the vehicle, such as interior or exterior lights, or for selecting a function for microphone  18 , such as a cellular phone versus an emergency communication device or recording device. Mirror housing  16   b  may also include controls, buttons or switches, shown generally at  48 , for selectively activating, deactivating or adjusting one or more accessories associated with the vehicle. For example, controls  48  may activate map reading lights on mirror housing  16   b , temperature displays, compass heading displays or the like, which may be displayed on a portion of mirror housing  16   b  and are thus easily visible to the driver of the vehicle. Alternatively, however, controls  46  and  48  on microphone module  10  and mirror housing  16   b , respectively, may control accessories or lights which are located on or within the vehicle and yet are remote from microphone module  10  and mirror  16 . 
     Referring now to  FIG. 7 , an accessory module  10 ′ may further include multiple accessories, components or devices associated with various control systems of the vehicle and connected with a vehicle control or the vehicle wiring harness. For example, accessory module  10 ′ may include a microphone  18 , an indicator  72 , a loudspeaker  42 , a Global Positioning System (GPS) antenna  50 , a motion sensor  52 , a rain sensor  54 , a video device or camera  56 , an interior light  58 , an automatic toll booth transducer  59 , a security system status indicator  70 , a compass and/or compass sensor  51 , a temperature display and/or temperature sensor  53 , a tire pressure indicator display  55 , a seat occupancy detection antenna and/or transducer  57 , and/or any other devices, components or circuitry which may be useful to mount in accessory module  10 ′. Preferably, camera  56  is a pixelated imaging array sensor, such as a CMOS imaging array or the like, a description of which is disclosed in commonly assigned U.S. Pat. No. 5,670,935, issued to Schofield et al., the disclosure of which is hereby incorporated herein by reference. The module  10 ′ may provide a location for these devices which is highly visible and eases user interface by the driver or passengers of the vehicle. Furthermore, mirror housing  16   b  may also include electrical devices and electronic components, such as other microphones  18 , indicators  72  and loudspeakers  42 , map reading lights  60 , compass  62 , display  64 , trip computer  66 , or other components or devices associated with the vehicle. Mirror harness  24  may provide power and/or control signals to these components or devices and may interconnect with the control circuitry of the devices and of an electrochromic mirror function control circuitry  68  for electronically adjusting the reflectivity of reflector  16   d  within mirror housing  16   b . Display  64  may display vehicle status or information displays, such as compass headings, interior or exterior temperatures, clock display, fuel level display, air bag status display, telephone dial information display, or other status displays of various components or devices associated with the vehicle. Information displayed in display  64  may be selectively displayed by an operator via controls  48  ( FIG. 6 ), or may be cyclically displayed or may be displayed when there is a change in status of one of the devices. 
     It is envisioned that accessory module  10 ′ may further include multiple electrical and/or electronic components, such as those described in commonly assigned, co-pending U.S. patent application Ser. No. 08/918,772, filed Aug. 25, 1997 by Deline et al., now U.S. Pat. No. 6,124,886, and Ser. No. 09/244,726, filed Feb. 5, 1999 by Deline et al., now U.S. Pat. No. 6,172,613, the disclosures of which are hereby incorporated herein by reference. The mirror and/or the microphone module may communicate with these or other devices or components within the vehicle as part of a Car Area Network (CAN) or multiplex system, such as is disclosed in commonly assigned U.S. Pat. No. 5,798,575, issued to O&#39;Farrell et al., PCT International Application published Sep. 25, 1997 under International Publication No. WO 97/34780, by Fletcher et al., PCT International Application No. PCT/IE98/00001, filed Jan. 9, 1998 by John P. Drummond et al. and published Jul. 16, 1998 under International Publication Number WO 98/30415, the disclosures of which are hereby incorporated herein by reference, a Local Interconnect Network (LIN), or similar communications protocols, which may support the control of mechatronic nodes in automotive distributor applications. 
     Accessory module  10 ′ may also include an illumination source  70  for a vehicle security system, such as an intrusion detection system, vehicle alarm system, vehicle antitheft system, or the like. The illumination source may be an incandescent source or a nonincandescent source. Preferably, illumination source  70  is a nonincandescent, solid state source such as a light emitting diode (LED), an electro-luminescent device or the like. The illumination source  70  is operable to blink or flash intermittently when the system is armed. Typically, such systems flash the illumination source rapidly at first for up to approximately 30 seconds (or longer) after arming of the system, and then intermittently flash the illumination source for a continuous period while the system is activated (for example, once every one to two seconds), thereby alerting people within the vehicle that the security system is activated. Optionally, the security system indicator may be provided by indicator  72 . Indicator  72  may provide an audio signal receiving status when the audio system is in use, and then provide a security system status signal when the audio system is deactivated and/or the security system is armed. 
     It is further envisioned that the illumination source for the vehicle security system may be included in a separate module or pod which may be mounted to the microphone or accessory module the mirror assembly, or the vehicle headliner. The illumination source module may be substantially similar to the microphone or accessory module discussed above and may clip or otherwise be mounted to the microphone module. For example, the illumination source module may snap into a mounting aperture in the microphone module or may be adhesively mounted to a side wall of the microphone housing. Alternately, the security system activation status source module may be mounted to the mirror assembly, such as to the mounting button, arm or mirror housing. The illumination source module may then be positioned below, above, or to either side of the mirror housing to facilitate viewing of the illumination source by passengers within the vehicle. The illumination source module may otherwise be mounted to the wire cover of the microphone module such that it is visible above the mirror housing. If the vehicle includes a header mounted mirror assembly, it is further envisioned that the illumination source module may be mounted to, or included as part of, the header mirror mounting bracketry or other mounting device. 
     By providing a vehicle security system illumination source module as a separate component, greater flexibility is achieved by the vehicle manufacturers. The separate security system module avoids the additional expenses required to tool two different mirror cases for vehicles with or without a security system. The optional pod or module with the illumination source may be simply installed as a vehicle option, or as an aftermarket device. Similar to the microphone and accessory modules discussed above, the illumination source module for the security system may further include other components, devices, controls or displays associated with the security system or other systems within the vehicle. It is further envisioned that other pods or modules which include one or more various components or devices associated with other systems or devices of the vehicle may be implemented to facilitate easy installation of the components of the systems either in the assembly plant or as aftermarket devices. 
     Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law.