Abstract:
Telephone sets can be fitted with auxiliary headset features but they will still require mechanical lifters to raise and lower the handset in response to a call. The lifter needs to be in circuit with some portion of the telephone set but it is impractical to modify an unlimited number of disparate set types. To solve this problem, the audio line cord, which is easily detachable, is passed through the lifter system and manually operable remote switch. The switch issues signals in tandem with audio signals on the handset cord and the lifter system differentiates the signals to respond only to switching signals intended to lift or lower the handset from its cradle.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is directed generally to a telephone headset apparatus and more particularly to a manually switch activated headset lifter apparatus which can be retrofitted to existing telephone sets without modification  
       BACKGROUND  
       [0002]     Communication systems for interconnection of a headset or other receiver with telephone systems are well known. Wireless systems add a new dimension to the use of specialized and report receivers interconnected into telephone, including Voice over IP (VOIP) networks. Such systems include a fixed transceiver which is connected to a telephone line with associated hardware to relay signals to and from a remote device. Wireless systems allow substantial freedom of movement during a telephone conversation since the user is not anchored to a telephone cord line. Such wireless systems typically include a base station inserted between the handset and the telephone itself, in effect tapping off the audio signals for transmission to and from the headset. Because the handset remains indirectly connected to the telephone via the wireless base that may contain switching circuits for selecting wireless headset or handset, the user still retains the ability to use the both the original handset and the wireless device.  
         [0003]     In many cases, the user may be located near the telephone set (e.g. to make an outgoing call from the telephone keypad), in which case the user could manually lift the handset to initiate the phone call. However, this may be an inconvenience, as it also requires the user to manually replace the handset at the end of the call.  
       SUMMARY OF THE INVENTION  
       [0004]     Generally, the present invention relates to a system and method of retrofitting an existing telephone set to have a lifter responsive to a switch and being able to install such equipment onto such existing phone set without material modification thereof.  
         [0005]     For example, there is disclosed a method of retrofitting a telephone set having a base unit, a handset, a handset cord connecting the handset to the base unit, and an electrically responsive handset lifter, having the steps of:  
         [0006]     electrically connecting the handset to the base unit via said handset cord through the lifter; and electrically connecting a lifter up/down actuator in said handset cord; and the configuring said lifter to sense the signal from said actuator through said headset cord with quick disconnect and thereby lifting or lowering the handset in response thereto.  
         [0007]     There is also disclosed a system for retrofitting a telephone set for remotely actuating a handset lifter, said telephone set having a base unit, a handset, a handset cord configured to carry audio signals between said base unit and said handset, and a lifter, which includes a command unit for configured to issue an actuation signal to said lifter, said unit being configured to transmit said actuation signal along said audio signal wires in said handset cord, and a sensor associated with said lifter and in circuit with said wires in said handset cord, for detecting said actuation signal from said unit and configured to reject audio signals carried on said wires, and passing said actuation signal through to said lifter for lifting and replacing the handset in response to said command unit.  
         [0008]     Numerous other inventive concepts and embodiments are disclosed and claimed in this document. This summary does not endeavor to touch on all of them. Reference should be had to the full specification and claims.  
     
    
     BRIEF DESCRIPTION OF THE INVENTION  
       [0009]     The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:  
         [0010]      FIG. 1  depicts a functional block diagram of the circuitry to implement a push button activated handset lifter apparatus. 
     
    
       [0011]     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.  
       DETAILED DESCRIPTION  
       [0012]     In general, the present invention is directed to a system, method and apparatus of a push button activated handset lifter device. It is well known that wireless or wired telephone headsets and associated amplifiers normally tap the analog line of a telephone handset than the line cord. The advantage of this arrangement is that, particularly, in digital telephone sets, the proprietary codes used by each set manufacturer need not be know. Furthermore, tapping into the line cord, means that the headset must be a complete phone, not just a handset replacement and the features of the telephone set would also have to be replicated.  
         [0013]     A convenient way to allow the user to take the phone off hook (i.e. raise the handset so that the headset system will able to intercept the voice signals) is to provide a manual system for direct actuation of the lifter system which can be added to the analog handset line. This may be in addition to some wireless or other lifter actuator, such as a switch on the lifter, etc. By adding the switch in the handset line, it makes it simple to retrofit any telephone with connectors (usually the RJ modular type) and no further retrofit of the phone is required.  
         [0014]     A functional block diagram embodiment of a push button activated, headset lifter system  100  is depicted in  FIG. 1 . A top level overview of the system operation follows. A standard office telephone  110  connected to a handset jack is connected to headset amplifier unit  120  by interconnect cable  130 . The headset amplifier unit  120  has modular jack  140  shown with  4  leads,  140  A thru  140  D, exiting the connector jack  140 . Leads  140  A &amp;  140  B carry audio signals generated by the microphone unit  150  en route to the telephone  110 , whereas, leads  140  C &amp;  140  D carry audio signals from the phone  110  destined for the headset speaker  160 . The push-button activation unit  170  houses, among other things, the user activated push-button  180 , whose output signal controls the phone handset lifter unit  185 . In this environment, the headset wearer can both answer (pick-up) and terminate (hang-up) phone calls without having to physically interact with the phone handset.  
         [0015]     A problem would arise in the use of a simple push button (make/break) connected to circuitry to raise and lower the handset. An audio (such as a voice) signal, which is simultaneously carried on the line may appear to mimic a signal which the lifting/lowering circuit would see as a signal to initiate such action. Such a false actuation would render the system unreliable.  
         [0016]     To prevent this, create a band pass filter which is configured to block audio signals which may appear as trigger signals. An example of such a signal might be the loud signal used in US telephone system to indicate that a user has left the handset off hook for a predetermined period of time, about 30 seconds. Of course it is necessary to select a bandpass value which is such that it does not interfere with normal audio signals in the narrow voice frequencies and amplitudes which the listener needs to receive.  
         [0017]     Now, a more detailed examination. When the user hears the phone  110  ringing with an incoming call, the user may initiate lifting the phone handset and accepting the call by depressing the manual actuation command unit (in this embodiment a push button, though it could be many type of signal generators)  180  for a predetermined time period, say more than generally 100 milliseconds and less than 2 seconds. The 100 ms wait time is not an absolute. It could be 25 or 50 ms, for example, but the longer the time, the more likely undesirable transient signals will be rejected. The 2 second maximum is likewise not an essential upper end. 0.5 or 1 second, for example could also be selected. The objective is for a human user to hold the switch engaged long enough to send a signal which is clearly not a transient and short enough to be convenient. When push button  180  is closed, resistor  200  discharges capacitor  190  so that current can be drawn through resistor  210 , which in turn activates the up logic circuitry.(capacitor  220  blocks the + DC from entering the headset amp  120 ). The discharging signal  230  is received and analyzed by logic circuit  240 . An active signal generator could be substituted for manual command unit  180  and associated RC circuitry. In the present case a declining exponential pulse is generated with a high peak to make it easily distinguishable from a similar audio signal (although it the preferred embodiment, such signals will be substantially filtered). It is possible to use other, even more distinguishable wave forms, such as square wave pulses, specific analog patterns or even digitally encoded ID signals which can be fully separated from audio. The preferred method recognizes the cost advantages of a simple RC network.  
         [0018]     If the logic circuit  240  determines the discharging signal  230  meets the predetermined criterion (time window) to initiate a call answer—i.e. lift UP signal (again, at time delay of more than 100 milliseconds and less than 2 seconds in duration), the logic circuit  240  will output an up command  250  which in turn activates the up switch  260  allowing current  270  to flow through the lifter motor  280  in the appropriate direction to begin physically lifting the phone handset. The lifter motor  280  may lift the phone handset until the Up Cycle Stop Sensor  290  senses the handset has reached a predetermined height (which may be determined by any number of sensor devices known in the art) and may then initiate a stop command  300  which may disengage the up switch  260  and halt the lifter motor  280 . With the handset now lifted (i.e. off hook state) above the threshold to allow for an incoming call to be received, the audio signal exits the phone  110  and traverses interconnect cable  130  to the headset amplifier  120 . The incoming audio signal is then routed from the headset amp  120  as a differential output signal applied to leads  140  C &amp;  140  D. The audio signal on leads  140  C &amp;  140  D traverses in order the headset connector  310 , coiled wire  320 , and the push-button activation unit  170  en route to headset speaker unit  160 . Wherein, capacitor  220  on wire lead  140  D serves as a coupling capacitor to pass the audio signal and block D.C. and/or transient discharging signals  230  generated by the push-button activation unit  170  as explained earlier, and resistor  410  on wire lead  140  C has a sufficiently large resistance, typically much greater than 300 ohms, so as not load down the audio signal en route to speaker  160 . And furthermore, the low pass filter circuitry comprised of resistor  210  and capacitor  330  shunts the audio signal on lead  140  D to ground just prior to the phone handset lifter unit  185 , thereby ensuring the audio signal might not inadvertadly trigger the logic unit  240  to issue an erroneous handset up/down command.  
         [0019]     Note that a digital (i.e., non-analog) version of this system is possible. The RC circuit would be replaced by known switching circuits with timers. Similarly, the user can hang-up and terminate phone calls by depressing the same push button  180  used to pick-up the original call. In this scenario, when the user wishes to terminate the call and replace the handset to its resting “down” position, the user may depress the push button  180  for a predetermined time period, say greater than 200 milliseconds (ms), but there are other options. The UP signal could be say 100 ms to 2 sec (or others as mentioned above) and a DOWN signal could be issued when the switch is activated for longer than the down signal (in this case &gt;2 second). Another scenario is the UP and DOWN signals are of the same length (for example &gt;100 ms,&lt;2 seconds, but toggle between up and down. This is a simpler construction but can be a bit confusing for the user. As before, this action discharges the energy stored in capacitor  190  through resistors  200  and  210 , (capacitor  220  blocks the discharging signal from entering the headset amp  120 ). The discharging signal  230  is received and analyzed by logic circuit  240 .  
         [0020]     If the logic circuit  240  determines the discharging signal  230  meets the predetermined criterion to initiate a call hang-up (time period greater than 2 ms in duration), the logic circuit  240  will output a down command  340  which in turn activates the down switch  350  allowing current  360  to flow through the lifter motor  280  in the appropriate direction to begin physically lowering the phone handset. The lifter motor  280  may then lower the phone handset until the Down Cycle Stop Sensor  370  senses the handset has reached a predetermined height and may then initiate a stop command  380  which may disengage the down switch  260  and halt the lifter motor  280 . In the example described above, the DOWN signal is inhibited during the lifting of the headset, and similarly, the UP signal is inhibited while the lifter device  100  is going down. This may, for example, ensure that the user does not mistakenly terminate a call pick-up by inadvertently hitting the push button  180  while the lifter is raising the handset.  
         [0021]     The above embodiment describes the push button activated, headset lifter device  100  utilizing analog electronics. A digital embodiment can also be envisioned where, for example, the logic circuit  240  in digital format may be programmed to recognize a single depression of the push button  180  as a request to answer the phone  110  when ringing, and a rapid sequence of two or more depressions of the push button  180  to signal a request to terminate the call and hang up. Many other variations can also be envisioned, for example a hybrid system part analog/part digital wherein the discharging signal via capacitor  190  may be digitized within the push button activation unit  170 , prior to transmission to a digital logic unit  240 .  
         [0022]     Another important feature of the present invention are the quick disconnect connectors  390  and  400  as incorporated in the push button activation unit  170 .  
         [0023]     These quick disconnect connectors may allow for the push button activation unit  170  to be easily retro-fitted into pre-existing telephone headset systems originally sold without the push-button activated call answering/call hang-up capability.  
         [0024]     As noted above, the present invention is applicable to telephone headset systems and is believed to be particularly useful for a quick disconnect push button activated headset lifter apparatus. The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification. The claims are intended to cover such modifications and devices.