Abstract:
A vibrating device for alerting a phone user of an incoming call includes a receiver of an electric signal representing the incoming call, and a converter which renders the electric signal into a mechanical movement that is felt by the skin of the user as a sensational touching. The converter contains a magnetostrictive generator controlled by an electric signal representing incoming signals. A telephone set incorporates the vibrating device into its ringer.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a field of telecommunications. More specifically, it relates to portable phones. Still more specifically, the present invention relates to novel method and apparatus for alerting a user of such a phone of an incoming call. 
     2. Description of the Related Art 
     For a number of years, portable phones have been well known. They are fed by a battery (-s) which makes them capable of being operative with no wire connection to a base unit. There are several kinds of such portable phones, cordless phones, radio phones, cellular phones, and pagers being exemplary of this category. 
     The portable phones are equipped with electronic ringers notifying users of incoming calls. However, situations can be easily imagined where an audible ringer would be noisy and thus inappropriate. During meetings, operations, at night, etc., any unexpected sound can be worrisome for those not involved. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the invention is to provide a method of and an apparatus for alerting a phone user of an incoming call, the method and apparatus keeping all the advantages of prior art whereas being free of its disadvantages. 
     A further object of the invention is to provide a method of and an apparatus for alerting a phone user of an incoming call, the alert being non-audible. 
     Still further object of the present invention is to provide a method of and apparatus for alerting a phone user by magnetic means for an incoming call, the magnetic means being magnetostrictive means. 
     According to the invention, a method of alerting a phone user of incoming calls is provided, the method comprising the steps of receiving an electric signal representing the incoming call and converting the electric signal into mechanical movement that can be felt by the skin of the user. 
     The electro-mechanical converting is proposed to perform by magnetostrictive means. 
     An apparatus for alerting a phone user of incoming calls is provided according to the present invention, the apparatus comprising means for receiving an electric signal representing the incoming call and means for converting said electric signal into mechanical movement that is sensationally touching for the user. 
     The converting means are magnetostrictive means. 
     The magnetostrictive means includes a magnetostrictive generator. 
     The magnetostrictive generator comprises a transformer, having a core made of a material exhibiting high magnetostrictive properties and primary and secondary windings wound around the core, and a switch controlled by the electric signal representing the incoming call. The primary and secondary windings are connected in series and paralleled by a capacitor, the parallel connection being connected in series with the switch. The primary winding is fed from an electric energy source. 
     The core is fixed at its one side while the other side is left free for movement. 
     The core is specifically made of annealed vanadium permendur. 
     Also, according to the present invention, a phone set is provided comprising an antenna connected to a receiver, a microcontroller (μcontroller) connected to the receiver and to a user interface, as well as a ringing device and a speaker circuitry connected to the μcontroller. The ringing device includes a magnetostrictive generator, to thus ensure that incoming calls be received in a physically sensible rather than in an acoustic mode. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     These and other objects, features and intended advantages of the invention will be more readily apparent by reference to the ensuing detailed description in conjunction with the accompanying drawings wherein: 
     FIG. 1 shows a schematic diagram of a magnetostrictive generator used for converting electric signals according to the present invention; 
     FIG. 2 illustrates a magnetostrictive transducer employed in the generator of FIG. 1; 
     FIG. 3 is a representation of a hysteresis loop generated in the operation of the transducer of FIG. 2; and 
     FIG. 4 depicts a structural diagram of a phone set using the generator of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a magnetostrictive generator  10  constructed in accordance with a broad aspect of the invention includes an autotransformer  12  having a primary winding  14  connected in series with a secondary winding  16 , the both windings being wound around a common core (not shown) formed of a material exhibiting high magnetostrictive properties. A tap  18  between the windings  14  and  16  is connected to a battery  20 . A capacitor  22  is connected in parallel with the primary and secondary windings  14 ,  16  of the transformer  12 . A transistor  24  is connected in series with the primary winding  12  and controlled from an input  26  through an isolating capacitor  28 . A storage capacitor  30  and a limiting resistor  32  connected in series are placed in parallel to the transformer  12  and a controlling junction of the transistor  24 . 
     In operation, briefly, when an electric signal appears at the input  26 , the transistor  24  opens and a current begins to flow through the primary winding  14  of the transformer  12 . Since the winding  12  and  14  are wound on the common core, the voltage developed across the primary winding  14  produces in turn a voltage across the secondary winding  16 , and the combination of the voltages across the windings  14 ,  16  is applied to charge the commutating capacitor  22 . During the most of the time the commutating capacitor  22  is being charged, the core of transformer  12  is in an nonsaturated state so it has a relatively high inductance and, therefore, the current flowing in the loop comprising the primary and secondary windings  14 ,  16  of the transformer  12  and the communicating capacitor  22  is relatively low. 
     As the charge upon the commutating capacitor  22  increases to a sizable value, the core of the transformer  12  saturates, and the inductance decreases to a lower value at which it can no longer support the high voltage across the capacitor  22 . Discharge of the energy stored in the commutating capacitor  22  through windings  14 ,  16  causes the current flowing through both the windings  14 ,  16  to substantially increase that drives the core further into saturation. The secondary winding  16  is formed of a much larger number of turns than the primary winding  14  and is connected so that the flux is additive when the commutating capacitor  22  is discharging. Thus, the large current flow back through the winding  16  further increases the magnetic field intensity in the core. At this point, the transistor  24  turns off due to a negative charge applied by the discharge through the RC chain  30 - 32 . The circuit is allowed to ring down until the circuit energy is dissipated, and the very large magnetic field intensity causes deformation of the highly magnetostrictive core of the transformer  12 . 
     The operation of the circuit of FIG. 2 can be further appreciated from inspection of the BH curve shown in FIG.  3 . Initially, the circuit begins operation around the origin of the BH on the B axis curve at point “A”. When the switch  26  is closed and the capacitor  27  begins to discharge through the primary winding  21  of the transformer  20 , the magnetic field intensity linearly increases until the transformer core reaches saturation at point “B”. Once the core of the transformer  20  reaches saturation, and the commutating capacitor  22  begins discharging because the core inductance of the transformer will no longer support the high voltage across the capacitor, the current sharply increases to thereby drive the core of the transformer  20  into hard saturation as illustrated at point “C” of the BH curve. Before reaching the point “C”, the switch  26  is opened. It is at the point “C” of the saturation of the core that its magnetostriction or deformation is greatest. The acoustic pulse is generated by the compression of the fluid created by the deformation of the core. As the circuit energy dissipates its inductance switches to the high state at point D. By now the current flow has started in the opposite direction. The core&#39;s BH valves follow the core material BH curve to point “E” somewhere on the curve. Because of the current reversal, the commutating capacitor has charged partially at point “F” at which the current has peaked. The circuit again establishes its neutral or at rest position, the “B” field is reduced so that the circuit comes to rest on the BH curve at point “G” which will lie somewhere on the B axis. Thereafter the processes are again repeated. The point on the vertical axis of the BH curve at which the transformer comes to rest is a function of the supply voltage, the time it takes to reach saturation from the rest position on the BH curve and the reset time. It should be noted that the BH curve which is generated is of a square loop configuration, that is, the BH curve has an essentially parallelogram configuration with flat upper and lower extremes and steeply rising sides. This is referred to herein as a “square loop” property. 
     Referring now to FIG. 2, the autotransformer  12  is shown with the primary winding  14  and the secondary winding  16  wound around a core  34 . It has been found in the construction of the transformer  12  that the fabrication of the transformer about a rolled cylindrical core of annealed vanadium permendur is particularly well suited to provide the high magnetostriction (and deformation) required. It is to be understood that other magnetic materials known in the art by their magnetostrictive properties can also be used for the core. 
     The windings  14 ,  16  and the left side of the core  34  are rigidly fixed. The right side of the core  34  is free to move when the magnetic field intensity causes deformation of the core. This flex can be felt by the user&#39;s skin as a sense of touch when the apparatus is placed into the phone and carried by the user. 
     Referring now to FIG. 4 where a typical digital cellular phone set  36  is shown incorporating the present invention, the phone set  36  comprises an input  38  with an antenna  40  connected to a receiver  42 , a μcontroller  44  connected to the output of the receiver  42 , a user interface circuitry  46  tied with the μcontroller  44 , a ringing device  48  and an earpiece amplifier and speaker portion  50 . In accordance with the principles of the present invention, the ringing device  48  incorporates a magnetostrictive generator  52  of the type described in the above. 
     In operation, an incoming signal is captured by the antenna  40  and sent to the receiver  42  where it is converted into a binary code. The binary code is read by the μcontroller  44  and processed as directed by its own internal software and by signals provided through the user interface  46 . In accordance with the operator&#39;s instructions that are input from the circuitry  46  into the μcontroller  44 , the latter sends an activation command to either the earpiece amplifier and speaker portion  50  or to the device  48  comprising the magnetostrictive generator  52 . The activation command is terminated when instructed through the user interface by the operator. When the activation command is received by the magnetostrictive generator  52 , the generator is activated in the manner described in the above to create a large magnetic field intensity. This results in the deformation of the core  34  that can be felt by the skin of the user carrying the phone set  36  while being unheard by anybody. 
     The foregoing description of the invention has been directed primarily to a particular preferred embodiment in accordance with the requirements of the patent statutes and for purposes of explanation and illustration. It will be apparent, however, to those skilled in the art that modifications and changes in the specifically described and illustrated method and apparatus may be made without departing from the scope and spirit of the invention which is thus not restricted to the particular form illustrated and described, but covers all the modifications which may fall within the scope of the following claims.