Patent Publication Number: US-6223060-B1

Title: Voice message recorder and limited range transmitter for use with telephones

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 08/933,022, filed Sep. 18, 1997, now abandoned, which is a continuation of U.S. application Ser. No. 08/677,082, filed Jul. 9, 1996, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 08/516,802, filed Aug. 18, 1995, now U.S. Pat. No. 5,568,538. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to telephone apparatus in general, and more particularly to message recording equipment to be used in conjunction therewith, and still more particularly to limited range transmission of signals for broadcast on a nearby radio receiver. 
     2. Description of the Related Art 
     There are already known various constructions of telephone apparatus, among them, besides the traditional wall-mounted, desk or nightstand units, the so-called cordless telephones that include a base unit and a handset unit that communicate with one another by limited range broadcasting, and the so-called cellular telephones that communicate either with a remote central base unit or directly with an overhead satellite. 
     Regardless of the construction of the telephone apparatus, though, there is often a pronounced need to create a memorandum of, for instance, a name and telephone number of a caller, a time and place of an event to attend, or the like, either while a particular telephone conversation is in progress, or immediately after its conclusion or, generally speaking, at any time. Traditionally, this was accomplished by having a notepad and a writing utensil handy close to the telephone. However, there is a tendency for one or the other, or both, of such items to disappear from its intended location just before a particularly important or crucial piece of information is to be jotted down, so that the telephone user has to interrupt the conversation and try to locate the missing item or a replacement for it. 
     A similar problem also exists when a more recent development in the information recording field, a so-called voice message recorder, is to be used instead of the paper-and-pencil duo. More particularly, message recorders of this type, which are designed to record a number of relatively short messages on digital data storage chips, are relatively small units that are easily misplaced or covered up by other items that may be present at the vicinity of the telephone apparatus, so that the telephone users again have to go to look for them, or fumble through papers and the like trying to locate them, sometimes in a futile effort, before being able to use them. Moreover, as a result of the miniature size and the resulting easy portability of such voice message recording units, it is highly likely that they will be transported to a location distant from its originally intended one, like to a different telephone apparatus or practically anywhere within the apartment or home, leaving the next potential user of the recording unit at a loss where to even start looking for the recording unit. 
     Telephones are finding increased usage in automobiles. Safety concerns dictate that drivers not be distracted by having to manually jot messages down on paper, or to hold a cellular telephone in one&#39;s hand while driving. Being able to record messages by voice alone, and being able to listen to recorded messages and to the voice of the other party on the telephone call without or with minor manual intervention, reduce the risk of automobile accidents. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art. 
     More particularly, it is an object of the present invention to provide a voice recording unit that does not possess the drawbacks of the known recording units of this type. 
     Still another object of the present invention is to devise a voice recording unit of the type here under consideration that is always readily available at the location of a telephone apparatus for use if desired. 
     It is yet another object of the present invention to design the above recording unit in such a manner as to be compatible with existing telephone apparatus of any type. 
     A further object of the present invention is to promote hands-free operation of cellular telephones in automobile environments. 
     A concomitant object of the present invention is so to construct the voice message recording unit of the above type as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation. 
     SUMMARY OF THE INVENTION 
     In keeping with the above objects and others which will become apparent hereafter, one feature of the present invention resides in a telephone apparatus that includes a handset unit having a mouthpiece portion to be located close to the mouth, and an earpiece portion to be situated at the ear, of a user in a use position of the handset unit, and a handgrip portion interconnecting the mouthpiece and earpiece portions, in combination with a voice message recording unit including an electric power source, a voice message recording device, a microphone operative for converting sounds into electrical signals and electrically connected to the voice message recording device for supplying the electrical signals thereto, means for controlling the operation of the voice message recording device in a recording and playback mode, and means for supporting the voice message recording unit on the handset unit so as to be disposed at the general vicinity of the user&#39;s mouth when the handset unit is in its use position. A particular advantage of the present invention as described so far is that, because of the presence of the aforementioned supporting means, the likelihood that the voice message recording unit could be misplaced is significantly reduced if not eliminated altogether. 
     Moreover, the controlling means advantageously include manually actuatable recording and playback controls which are located at one and/or both opposite lateral side regions of the handset unit. These controls are readily accessible to the user. 
     In one advantageous embodiment of the present invention, the telephone apparatus further includes a base unit and a telephone cord connected to the base unit and having a modular telephone plug at a free end thereof, and the handset unit has a modular telephone receptacle therein. Then, it is advantageous for the voice message recording unit to further include a casing accommodating all other of its components, and means for establishing electrical connections between the modular telephone plug of the telephone cord and the modular telephone receptacle of the handset unit. Such establishing means advantageously includes an auxiliary modular telephone receptacle in the casing for receiving the plug of the cord, an auxiliary modular telephone plug to be inserted into the receptacle of the handset unit, a short length of telephone cord connected to the auxiliary plug and secured to the casing, and electrically conductive means passing through the interior of the casing and electrically connecting the auxiliary receptacle with the short length of telephone cord. 
     In this context, it is especially advantageous when the handset unit includes a loudspeaker received within its earpiece portion, when the electrically conductive means of the voice message recording unit includes at least one portion forming a part of an electrically conductive path between the base unit and the loudspeaker of the handset unit, and when the voice message recording unit includes at least one output for electric signals representative of previously recorded voice messages, and means for electrically connecting the output to the aforementioned at least one portion of the electrically conductive means. In this manner, a separate loudspeaker for the voice message recording unit can be dispensed with in that the telephone handset unit loudspeaker is shared by the handset unit and the recording unit. 
     According to another advantageous aspect of the present invention, the handset unit includes a handset proper and a flap hingedly connected to the handset, in which case the supporting means supports the voice message recording unit on the flap. The voice message recording unit may then include its own casing that accommodates the other components of the voice message recording unit, in which event the supporting means advantageously includes connecting means connected to one and engaging the other of the casing and the flap. However, in an alternative, the flap may include one shell part hingedly connected to the handset and another shell part secured to the one shell part, the shell parts accommodating the voice message recording unit between themselves to serve as the supporting means. 
     Another advantageous aspect of the present invention is embodied in mounting a casing of the voice message recording unit intermediate the handset and a cellular battery pack. The casing is slim and compact and virtually unnoticeable when so mounted. The manual controls are nevertheless readily accessible from die lateral edge regions of the casing. The casing is readily mountable and demountable from its use position in which it is sandwiched between the handset and the battery pack. 
     It is further advantageous, in accordance with another feature of the present invention, if the voice message recording unit further includes means for processing electrical signals that are representative of voice messages previously recorded and appearing on at least one output of the voice message recording device to convert them into corresponding audible sounds. Such processing means may include a dedicated loudspeaker or an AM/FM transmitter, or both, forming a part of the voice message recording unit and electrically connected with the at least one output of the voice message recording device. The transmitter, if present, is operative for broadcasting AM/FM signals corresponding to the electrical signals for reception at and conversion thereof into the audible signals by a nearby multipurpose radio receiver. If both the loudspeaker and the transmitter are provided, then it is advantageous to provide a selector switch movable between two positions in which it connects the at least one output of the voice message recording device with one of the loudspeaker and the transmitter to the exclusion of the other. 
     Rather than broadcasting recorded messages to the radio receiver, another aspect of this invention is to broadcast the sounds relayed by the voice of the other party (human or machine) on the telephone call to the radio receiver. This is especially advantageous in an automotive environment so that the driver need not hold the telephone loudspeaker to his or her ear in order to listen to the other party, thereby promoting traffic safety. 
     In accordance with another facet of the present invention, the voice message recording unit includes a casing that accommodates its other components, and there is further provided a case for receiving the handset unit. Under these circumstances, the supporting means advantageously includes means for forming a pocket on the exterior of the case for partially receiving the voice message recording unit. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a perspective exploded view of an embodiment of a telephone apparatus and voice recording unit combination of the present invention; 
     FIG. 2 is a simplified block diagram showing certain components of the voice recording unit of FIG.  1  and electrical interconnections between them; 
     FIG. 3 is a perspective view of a modified embodiment of the combination of the present invention as embodied in conjunction with one cordless telephone apparatus construction; 
     FIG. 4 is a block diagram similar to that of FIG. 2 but showing a modification of the recording unit; 
     FIG. 5 is a perspective view akin to that of FIG. 3 but showing the present invention as used in conjunction with a different construction of the cordless telephone apparatus; 
     FIG. 6 is a perspective view of a further modification of the cordless telephone apparatus and of the recording unit associated therewith; 
     FIG. 7 is a broken-away, perspective view of a modification of the telephone apparatus of FIG. 5, equipped with the present invention; 
     FIG. 8 is an exploded, perspective view of another embodiment of a telephone apparatus and voice recording unit combination of the present invention; 
     FIG. 9 is a broken-away, sectional view taken on line  9 — 9  of FIG. 8 after assembly; 
     FIG. 10 is a broken-away, sectional view taken on line  10 — 10  of FIG. 8 after assembly; 
     FIG. 11 is a side elevational view of the embodiment of FIG. 8 after assembly; 
     FIG. 12 is an electrical circuit schematic for use with the embodiment of FIG. 8; and 
     FIG. 13 is an alternative electrical circuit useful for any of the disclosed embodiments of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawing in detail, and first to FIG. 1 thereof, it may be seen that the reference numeral  10  has been used therein to identify a telephone apparatus of the type in conjunction with which the present invention is contemplated to be used. The telephone apparatus  10  itself may be of almost any known construction and configuration, so long as it possesses those features, which will become readily apparent as the present description proceeds, that make it compatible with the concepts embodied in the present invention. In the exemplary embodiment shown, the telephone apparatus  10  is constructed and used as a wall-mounted unit, as it frequently is in household kitchens and similar relatively busy areas where it is typically desired for the telephone apparatus  10  to be out of the way of other activities taking place there, yet to be close at hand for use when needed. However, it will be appreciated that the wall-mounted feature is not critical to the present invention. 
     The illustrated telephone apparatus  10  includes, as one of its main components, a handset unit  11 . The handset unit  11  is shown to include an earpiece portion  12  and a mouthpiece portion  13  that are connected with one another by a handgrip portion  14 . As is customary, the earpiece portion  12  is provided in its interior with a sound generating device including an amplifier and a loudspeaker  12   a , while a microphone is accommodated inside the mouthpiece portion  13 . These electronic devices, as well as others that are contained either within the handset unit  11  or in or on a base unit  15  that constitutes another main component of the telephone apparatus  10 , are of conventional constructions so that they need not be illustrated or discussed here in detail, nor will they be. Suffice it to say that such devices are incorporated in an electronic circuitry that converts sounds picked up by the microphone into electrical signals to be sent from the base unit  15  into a telephone line, and also converts incoming electrical signals from the telephone line into sounds issued by the loudspeaker. 
     As shown, the base unit  15  is provided with a control panel  16  that again is of a known construction so that it need not be explained here in any detail. The illustrated control panel  16  includes a keypad that includes the customary numerical and other keys to be used in dialing remote subscribers and/or sending data to remote computers or the like once the telephone connection with them is established. Here again, the provision of the keypad on the base unit  15  is not critical to the invention; instead, it could be mounted on the handset unit  11  aid particularly on its handgrip portion  14 . The base or wall unit  15  is shown to be provided with two recesses  17  and  18  that partially receive the earpiece portion  12  and the mouthpiece portion  13  of the handset  11  when the latter is “on hook”. 
     What is also shown in FIG. 1 of the drawing is that a telephone cord  19  extends from the base unit  15 . This telephone cord  19  is provided at least at its end that is remote from the base unit  15  with a modular plug  20 . Traditionally, this telephone plug  20  was received and releasably locked in place in a substantially complementarily configured socket  21  that is provided in the mouthpiece portion  13  of the handset unit  11 . That is no longer true when the present invention is being used. 
     Rather, in accordance with the present invention, there is provided a miniature voice recording unit  30  that is interposed between the telephone plug  20  and the telephone socket  21 . As shown, the unit  30  includes a casing  31  that is provided at its one end face with an auxiliary modular telephone socket or receptacle  32 . According to the present invention, the socket  32  is to receive and establish the requisite electrical contacts with the modular plug  20  of the telephone cord  19 . Also, a detangler could be interposed between the socket  32  and the plug  20  so that the telephone cord  19  will not twist and become tangled with itself. 
     Moreover, a telephone cord  33  of a relatively short length extends out of the casing  31  at the opposite end face thereof and carries at its free end that is remote from the casing  31  an auxiliary telephone plug  34 . In further accord with the invention, it is this auxiliary telephone plug  34  that is plugged or inserted into the modular telephone socket  21  of the handset  11  and establishes the necessary electrical contacts therewith. 
     The casing  31  further carries two switches or buttons  35  and  36  that control recording and playback, respectively but not necessarily in that order, and another switch  37  that renders it possible to switch between various information carrying channels, in a manner that is well known. The casing  31  is also provided with perforations  38  that are distributed in an orderly fashion and serve as sound conduits to a microphone that is accommodated inside the casing  31  and hence is not shown here. 
     The switches  35  to  37  and the various control circuits in which they are incorporated, as well as the operation of such circuits, are so well known that they need not be discussed here to any greater extent than will be done presently in conjunction with FIG. 2 of the drawing. As shown there, a recorder device  39 , which is of any known construction, preferably including a digital data storage integrated circuit chip, is accommodated in the interior of the casing  31  and is connected by respective electrical leads with the respective switches  35 ,  36  and  37  to enable the latter to control its operation. The recorder device  39  further includes a pair of output terminals that are respectively connected by wires or other electrical conductors  40  to two of the four leads  33  that are shown to extend from the receptacle  32  first through the interior of the casing  31  and then beyond it to the plug  34 . 
     The recorder device  39  also has a pair of input terminals that are electrically connected with an only diagrammatically indicated microphone  41 . A battery  42  that is also mounted in the interior of the casing  31  supplies electric current to the recorder device  39  and via the same to the microphone  41  and to the electrical leads  40 . It should be clear by now, considering the fact that the microphone  41  is accommodated in the casing  31  and a corresponding loudspeaker is conspicuously absent therefrom, that the two leads  33  to which the electrical conductors  40  and hence the output terminals of the recorder unit  39  are connected are those that lead to the aforementioned loudspeaker accommodated in the earpiece portion  12  of the handset unit  11  of the telephone apparatus  10 , and that this loudspeaker consequently doubles up as a loudspeaker for the voice message recording unit  30 . 
     In operation, the telephone apparatus  10 , when it is to be used merely to make telephone calls, can be operated in the usual manner, that is as if the recording unit  30  were not interposed between it and the electrical cord  19 . This is so because unimpeded electrically conductive paths exist through the voice message recording unit  30  from the plug  20  of the cord  19 , which is indicated in FIG. 2 by respective small rectangles representative of the respective electrical contacts of the plug  20 , through the receptacle  32  all the way to the plug  34 . As a result, the voice message recording unit  30  is so to speak transparent to the telephone apparatus  10  under these circumstances. 
     Yet, if the user of the telephone apparatus  10  feels that he or she should record some message of his or her own to serve as a reminder at a later point of time, he or she can do it by simply depressing the appropriate one(s) of the buttons  35 ,  36  and  37  and talking into the microphone  41  through the perforations  38  of the casing  31 . It will be appreciated that, inasmuch as the unit  31  is self-contained as far as the recording function is concerned, the recording can take place even during an ongoing telephone call, or at any other appropriate time, either immediately following a telephone conversation or independently thereof, depending on what triggered the perceived need for using the recording unit  30  for recording the message. On the other hand, since the telephone apparatus  10  and the recording unit  30  share the same loudspeaker (that of the telephone apparatus  10 ) in this particular implementation of the present invention, it is at least more practical to play back the previously recorded messages at a time when the telephone apparatus  10  is not being used for making any telephone calls. 
     Turning now to FIG. 3 of the drawing, it should be self-evident that it reveals an implementation of the present invention in conjunction with a so-called cordless or cellular telephone apparatus including at least a handset unit  11 ′. No distinction will be made now or later between such portable telephone apparatus types inasmuch as the principles of the present invention are the same or at least very similar in both cases. However, a single prime will be used now with each of the reference numerals of this unit  11 ′, and a double prime later, to distinguish them from functionally equivalent parts of the telephone apparatus  10  shown in FIG. 1 of the drawing. 
     Here, the hand-held unit  11 ′ also includes an earpiece portion  12 ′ and a mouthpiece portion  13 ′, but it is also provided on its handgrip portion  14 ′ with a control panel  16 ′ that is equipped with the aforementioned keypad or the like. Moreover, the hand-held or handset unit  11 ′ is shown to be constructed as a so-called “flip”-type telephone unit in that it is equipped with a flap  43  that is hingedly connected with the handset unit  11 ′ proper for pivoting into and out of a position in which it is juxtaposed with the control panel  16 ′. 
     The present invention utilizes the presence of this flap  43 , which traditionally has no electrical or electronic components supported thereon or received therein, for supporting the voice message recording unit  31  of the present invention at a location that is close to the mouth of a user  52  when the flap  43  is in its illustrated flipped-open position. To hold the recording unit  31  in place on the flap  43 , there are provided respective straps  44 . These straps  44  can be constructed as resilient metal components rigidly connected with one and resiliently engaging the other of the unit  31  and the flap  43 , for instance. However, they could also be constituted by any other clamping or fastening components, of which so-called Velcro™ fasteners are just one example. FIG. 3 also shows that the hand-held telephone unit  11 ′ is equipped with an antenna  50 , as is usual in this context. 
     For use with the detached, portable handset unit  11 ′, the message recording device  30 ′ is constructed as a self-contained unit, that is, it is equipped with its own means for reconverting the stored electrical signals representative of the recorded messages into sounds. This is so because the output lines  40  of the recorder  39  can no longer be conveniently connected to the loudspeaker of the handset  11 ′. In the simplest case, a separate loudspeaker  45  is accommodated in the interior of the casing  31 , in which case the output leads  40  of the recorder  39  are directly connected thereto. At this juncture, it is to be mentioned that, while the recorder device  39  is shown to have respective pairs of inputs and outputs connected with the various components such as the switches  35  to  37 , the microphone  41 , the battery  42  etc., in practice it will be usually more convenient to provide a common ground for all of such components, and have just a single input or output on the recorder device  39  for each of them. 
     While FIG. 4 shows the provision of the separate or dedicated loudspeaker  45  in the casing  31 , it shows something more as well, namely the presence of an AM or FM transmitter  46  in the casing  31 . The loudspeaker  45  and the transmitter  46  can be provided as mutually exclusive options each connected directly with the output leads  40  of the recorder  39 . However, it is advantageous to equip the recording unit  30  with both of them, and to provide an additional switch  47  interposed between the output lines  40  and the loudspeaker  45 , on the one hand, and the transmitter  46 , on the other hand, thus enabling the user of the device  30  to select which one of them to use in any particular instance. 
     Obviously, when the loudspeaker  45  is in use, it will generate sounds during playback. However, given the miniature size of the unit  30  and of its components, such sounds may be too faint to be heard in a noisy environment, such as in a moving car. If, however, an AM or FM radio or similar receiver is available at the location at which the playback is to take place, it can be used for generating more readily perceptible sounds, in that the switch  47  is flipped into its position in which it connects the output leads of the recorder  39  exclusively with the transmitter  46 . The latter then transmits signals at a frequency that is not used by any local stations and at a power that is so low as not to have any noticeable impact beyond the immediate vicinity of the handset  11 ′ and of the aforementioned FM receiver. 
     Thus, when the latter is tuned to the transmission frequency of the transmitter  46 , it will amplify the signals broadcast by the transmitter  46  to a level at which the sounds can be heard with sufficient clarity over the background noise. For almost universal use, it is best to tune the transmitter  46  to a frequency that is reserved all over the country for local announcements (usually traffic reports broadcast to the general public), but is being actually used only in certain very limited areas. Advantageous frequencies are 88.1 MHz (FM) and 640 kHz (AM) for stations in the United States, and 88.15 MHz (FM) and 639 kHz (AM) for stations in Europe. The choice between AM and FM and the choice between U.S. and European modes of operation can be made by one or more selector switches. It goes without saying that the power of the transmitter  46  has to be so low as not to interfere with this operation, that is, not to be picked up by other radio receivers located at even a relatively small distance (that between two cars) from the intended receiver and tuned to the same frequency, and that the playback will be possible or effective only outside the areas in which the local announcements are being broadcast. 
     FIG. 5 of the drawing illustrates, in a somewhat simplified manner, how the aforementioned recording unit, which is indicated at 30′ this time, can be incorporated into the flip-type telephone unit or handset  11 ′. In this instance, the flap  43 ′ is shown to consist of two shell-shaped parts  43   a  and  43   b  that are joined together in any known manner. In certain “flip-phone” models, the flap  43 ′ is constructed in that manner to begin with. In that case, the handset  11  can be easily retrofitted with the voice message recording unit  30 ′ of the present invention by simply disconnecting the shell part  43   b  from the shell part  43   a  (the latter being usually the one that is hinged to the handset  11 ′ proper) and either replacing it with a substitute one that has all of the aforementioned components of the voice message recording unit  30 ′ already mounted thereon (as described below in connection with FIG.  7 ), or reconnecting it with the shell part  43   a  after the above components have been sandwiched between the shell parts  43   a  and  43   b , typically in the form of a printed circuit board carrying such individual components as well as the electrical connections between them. 
     It goes without saying that one or the other of the shell parts  43   a  and  43   b  may have to be provided with perforations in order to present sound passageways into and/or out of the interior of the casing that is constituted by the assembled flap  43 ′ in this particular instance. It is also to be understood that, even though this has been omitted from FIG. 5 in order not to unduly encumber the drawing, the flap or casing  43 ′ carries one or more of the aforementioned switches or buttons  35  to  37  and  47  in a manner making them easily accessible from the exterior of the flap  43 ′. While such switches  35  to  37  and/or  47  could be located at one or the other of the major surfaces of the flap  43 ′, it is currently preferred to arrange than at opposite lateral edge regions of the flap  43 ′, that is those edge regions that extend from the hinges to the free end portion of the flap  43 ′, and advantageously close to the latter. 
     A relatively recent development in the field of wireless telecommunications, or at least of cellular communications, is the so-called “flipless” cellular or portable telephone handset unit like that indicated at  11 ″ in FIG.  6 . Of course, since the telephone handset unit  11 ″ of this type is not equipped with a flippable flap, it was necessary to develop different means for supporting the recorder unit  30 ″ on the handset unit  11 ″ at the general vicinity of the mouth of the user of the telephone handset unit  11 ″. 
     Such novel supporting means includes, on a carrying case  48  of leather, vinyl, fabric or other similar natural or synthetic material which may be provided in any event in order to protect the handset unit  11 ″ from damage, shock and/or other undesirable environmental influences, a pouch-like pocket  49 , preferably of a stretch, elastic material, for partially and snugly receiving the recording unit  30 ″. As illustrated, the pocket  49  is situated at the side of the carrying case  48 , extends from close to the bottom to about half-way up the height of the case  48 , and opens in the upward direction as considered in the illustrated orientation that corresponds to that in which the telephone handset unit  11 ″ is being usually used. 
     In this instance, the voice message recording unit  30 ″ has a configuration resembling that of a pen or similar writing utensil, and is inserted into the open end of the pocket  49  from above. Thus, under normal circumstances, the gravity pull will act to keep the voice message recording unit  30 ″ safely in the pocket  49 . However, the voice message recording unit  30 ″ is preferably received in the pocket  49  with a certain amount of frictional engagement so as to prevent it from inadvertently slipping out of the pocket  49  when the telephone handset unit  11 ″ is held in any other than its use position, or when the handset unit  11 ″ is being displaced, possibly with a jerky motion. It may be seen in FIG. 6 that a substantial part of the elongated voice message recording unit  30 ″ projects out of the pocket  49 , and that this projecting part carries at least the switches  35 ″ and  36 ″ and the microphone  41 ″, thus making them accessible for manipulation in the first case, and for unimpeded sound propagation in the second case. 
     FIG. 7 depicts the lower end of a flip-type telephone unit or handset  11 ″Δ modified from that shown in FIG. 5, but still having a flap  54  constructed of two shell parts  54   a  and  54   b.  Shell part  54   a  is hinged to the handset proper, while shell part  54   b  is removably connected to shell part  54   a.    
     The removable shell part  54   b  is advantageously provided with all the aforementioned components of the voice message recording unit mounted thereon. Hence, a user can remove the original factory-installed shell part, and substitute the shell part  54   b  equipped with the recording unit of this invention. Of course, a manufacturer could also supply the telephone unit with the recording unit already built in. 
     FIG. 7 also shows a slide switch  56  and push buttons  58  and  60  located at the lateral edges of the flap  54  to enable the user to have ready access thereto to control the recording unit. 
     FIGS. 8-11 depict another advantageous embodiment  100  for use with a conventional cellular telephone comprising a handset  102  of the type shown in FIGS. 5 and 7, and a battery pack  104  mounted at the rear of the handset. As is conventional in this art, the pack  104  has a pair of elongated slide rails  106 ,  108  which slide along and normally engage a pair of elongated channels  110 ,  112  formed at opposite lateral sides of the handset  102 . A resilient latch  114  (see FIG. 10) on the pack  104  has a latch portion  116  which normally engages with a snap-type action a complementarily configured latching recess  118  formed at the rear of the handset. Electrical contacts on the inner face of the pack  104  (hidden in FIG. 8) make electrical connection to the electrical contacts  120 ,  122  on the inner face of the handset when the pack is mounted so that electrical power is supplied to the handset. 
     As described so far, the handset and pack are entirely conventional and need no extended discussion. Commercial cellular telephones of this type are currently being marketed by Motorola, Inc., Ericsson, Inc. and Nokia, Inc. What is new is the detachable mounting of a casing  130  between the inner faces of the handset and battery pack. The casing  130  is a slim, compact module having a generally rectangular parallelepiped shape. One face of the module, i.e., the one that faces the inner face of the handset, is provided with a pair of elongated slide tracks  132 ,  134  analogous to slide rails  106 ,  108 . Slide tracks  132 ,  134  slide along and engage the channels  110 ,  112  in the same manner as the slide rails  106 ,  108  (see FIG.  9 ). The opposite face of the module, i.e., the one that faces the inner face of the pack, is provided with a pair of elongated passages  136 ,  138  analogous to the channels  110 ,  112 . The passages  136 ,  138  receive the slide rails  106 ,  108  of the pack. The resultant sandwich-type mounting is shown in FIGS. 9-11. 
     The casing  130  also has a resilient latch member  140  analogous to latch  114 . The latch member  140  has a latch part  142  analogous to latch portion  116 . The latch part  142  engages with snap action the latching recess  118 . The casing  130  also has a latch cavity  143  analogous to latching recess  118 . The latch portion  116  engages the latching recess  118  with a snap action in an assembled condition of use. Electrical contacts  144 ,  146  on one face of the casing  130  make electrical contact with non-illustrated contacts on the pack to supply electrical power to electrical components in the casing. The opposite face of the casing  130  also has electrical contacts which connect to electrical contacts  120 ,  122  to complete the delivery of power to the handset. 
     The mounting of the casing  130  is accomplished much like the pack is mounted on the handset, with a combination “slide and locking” action. To remove the casing  130 , one pushes the latch member  140  to its dashed line position in FIG.  10 . This pushing action causes the latch part  142  to pivot about living hinge  141  rearwardly out of the latching recess, again in a manner analogous to the operation of the resilient latch  114  and its latching portion  116 . Mounting of the casing  130  is quick and easy. No modification to the handset and the pack is required or desired. 
     The electrical components mounted within the casing  130  can, for example, be the voice recording unit components described above. As shown in FIG. 12, the message recording device  150  has an input connected to a microphone  152 , and its output connected to either an on-board local speaker  154 , or to a transmitter  156  for transmission to a nearby radio receiver, such as a car radio, depending on the position of the selector switch S. The transmitter can be AM or FM, tunable to either U.S. or European stations, as described above. 
     The manual controls, e.g., play  160 , record  162 , rewind  164  and fast forward  166 , are mounted at the lateral edge regions of the casing (see FIGS.  8  and  11 ) for ease of accessibility. An on-board set of batteries  168  may be optionally provided, which is especially useful as a backup power supply in case the main pack  104  fails. 
     Rather than using the transmitter  156  to broadcast messages recorded by the recording device  150 , the casing  130  can house components that broadcast any electrical signal indicative of sound, including the voice of the other party (human or machine) on the telephone call. As shown in FIG. 13, the cellular telephone  102  which, of course, is a transceiver receives telephone signals and rather than, or in addition to, conducting these signals to an on-board loudspeaker, these signals are amplified in amplifier  170  and conducted to an AM transmitter  172  or an FM transmitter  174  depending on the selections made by the AM/FM selector switch  176  and the U.S./European selector switch  178 . The amplified signals are transmitted by the selected transmitter under low power, e.g., less than 5 watts, to the automobile radio which receives the signals and broadcasts them over the radio&#39;s speakers with an amplitude sufficient for the driver to hear the ongoing conversation over the telephone, all without having to hold the handset up to the driver&#39;s ear. 
     A telephone battery charger  180  may optionally be used to charge the battery pack, or charge batteries within the casing, or to directly power the components within the casing. The charger  180  is advantageously plugged into the cigarette lighter receptacle. In the preferred application, the components are automatically normally de-energized or “off” to minimize battery drain. Transmission occurs only when a conversation is started, e.g., when the telephone call is initiated by depressing the “send” key. 
     It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above. 
     While the present invention has been described and illustrated herein as embodied in specific constructions of a voice message recording unit and a limited range transmitter for use in conjunction with a variety of telephone apparatus, it is not limited to the details of this particular construction, since various modifications and structural changes may be made without departing from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.