BACKGROUND OF THE INVENTION AND PRIOR ART The present invention refers to an adapter comprising: an adapter unit having an electric circuit; a first contact member connectable to a first contact member of a first unit ; a second contact member connected to the electric circuit and connectable to a second contact member of the first unit; and a third contact member connected to the electric circuit and being arranged to receive a third contact member of a second unit.

So called hands-free sets are available for various models of mobile phones. However, substantially each model has a hands-free set of its own, which means that each hands-free set is only connectable to a single model of a mobile phone.

This is a disadvantage for the users, since they have to buy a new hands-free set when they change mobile phone. Since such hands-free sets can be rather expensive, it is disadvantageous that they are useful in connection with one single apparatus only.

Furthermore, the such hands-free sets available for mobile phones are not adapted to other electronic equipment, such a computers, portable cassette tape recorders, CD-players, MP3-players, etc.

Another problem is that mobile phones can only operate together with one single hands-free set. Conventional headsets, to be used together with music-apparatuses of

various kinds, computers etc., therefore cannot be connected to a mobile phone.

SUMMARY OF THE INVENTION The object of the present invention is to overcome the problems discussed above. Especially, an object is to provide a device enabling the use of a standard hands-free set together with a plurality of various apparatuses.

This object is obtained by an adapter comprising: an adapter unit having an electric circuit; a first contact member connectable to a first contact member of a first unit; a second contact member connected to the electric circuit and connectable to a second contact member of the first unit; and a third contact member connected to the electric circuit and being arranged to receive a third contact member of a second unit, one of the first unit and the second unit being a set comprising a speaker and a microphone, and the other of the first unit and the second unit being an electronic device, having a speaker output and a microphone input, wherein the electric circuit is arranged to adapt the microphone signal of the second unit to the microphone signal required by the first unit.

Such an adapter makes it possible to connect a hands-free set of an arbitrary kind with any mobile phone. Moreover, by means of such an adapter it is possible to use any mobile phone hands-free set together with any kind of apparatus, such as tape recorders, MP3-players, CD-players, computers etc. The applicability and use of a given hands-free set can thus be expanded. The adapter unit may advantageously be

designed as an adapter box having a casing enclosing at least the electric circuit and possible one or several of the contact members.

According to an embodiment of the invention, the electric circuit comprises a voltage increasing means. By such a voltage increasing means, the relatively low output voltage of said microphone can be adapted to the voltage required by said electronic device. Advantageously, the electric circuit comprises a voltage source, e. g. in the form of a battery.

Moreover, the electric circuit may comprise a resistance in series with the voltage source.

According to a further embodiment of the invention, the electric circuit has a first pole and a second pole, the second contact member has a first pole connected to the first pole of the electric circuit and a second pole connected to the second pole of the electric circuit, and the third contact member has a first pole connected to the first pole of the electric circuit and a second pole connected to the electric circuit. The first contact member of the adapter may have a first pole connected to a third pole of the third contact member of the adapter. Moreover, the first contact member of the adapter may have a second pole connected to the second pole of the third contact member of the adapter.

According to a further embodiment of the invention, the first contact member of the first unit comprises a standard microphone jack. Such a standard jack requires an input signal with a voltage, which is higher than the voltage provided by many microphones, e. g. a microphone of a mobile phone hands-free set. The first contact member of the adapter may then comprise a first male contact member, which is connected to the adapter unit via a first electric cable member. Thus the adapter may comprise a cable connected to

and extending from the electric circuit to a male contact member, preferably a standard microphone plug.

According to a further embodiment of the invention, the second contact member of the first member comprises a standard speaker jack. The second contact member of the adapter may then comprise a second male contact member, which is connected to the adapter unit via a second electric cable member, preferably a standard speaker plug.

According to any one of the preceding claims, the third contact member of the adapter comprises a third female contact member and the third contact member of the second unit comprises a third male contact member. Preferably, the second unit is or includes a mobile phone hands-free set.

Furthermore, the third female contact member of the adapter may be a jack adapted to a mobile phone hands-free set.

According to a further embodiment of the invention, the adapter comprises a fourth contact member connectable to a contact member of a separate speaker and a fifth contact member connected to the electric circuit and connectable to a separate microphone. By such a design the adapter may also be connected to a standard headset, wherein the headset or the hands-free set may be used by a user together with any electronic device such as a tape recorder, a computer, a CD- player etc. Moreover, the adapter may comprise a sixth contact member connected to the electric circuit and connectable to a mobile phone, wherein the sixth contact member is arranged to receive a contact member of a mobile phone. By such a design a user have several options, he may use a head set or a hands-free set together with a mobile phone or an electronic device. It is also possible to operate the mobile phone at the same time as the user operates a computer.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is now to be described by means of preferred embodiments and with reference to the accompanying drawings.

Fig 1 discloses a schematically an adapter according to a first embodiment of the invention.

Fig 2 discloses a schematically an adapter according to a second embodiment of the invention.

Fig 3 discloses a schematically an adapter according to a third embodiment of the invention.

Fig 4 discloses a schematically an adapter according to a fourth embodiment of the invention.

Fig 5 discloses a schematically an adapter according to a fifth embodiment of the invention.

Fig 6 discloses a schematically an adapter according to a sixth embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Fig 1 discloses a first embodiment of an adapter comprising an adapter unit 1. The adapter unit 1 comprises a schematically indicated casing 2 forming a separate box. The adapter unit comprises an electric circuit including a voltage source in the form of a battery 3 and a resistance in the form of a resistor 4. Furthermore, the adapter comprises a first contact member 5, which is connectable to a first contact member 6 of a first unit 7, and a second contact member 8, which is connected to the electric circuit 3,4 and connectable to a second contact member 9 of the first unit 7. The first unit 7 is in the first embodiment an electronic device, such as a portable or stationary computer, a CD-player, a tape recorder, an MP3-player, etc.

The first contact member 5 is a standard speaker or earphone plug, wherein the first contact member 6 is a female output member in the form of a standard speaker or earphone jack.

The second contact member 8 is a standard microphone plug, wherein the second contact member 9 is female input member in the form of a standard microphone jack. The first contact member 5 and the second contact member 8 are, in the embodiment disclosed, connected to the box of the adapter unit 1 via a respective electric cable 10,11.

The adapter also comprises a third contact member 13, which is connected to the electric circuit 3,4 and arranged to receive a third contact member 14 of a second unit 15. In the embodiment disclosed, the second unit 15 is a schematically shown mobile phone hands-free set, preferably such a portable hands-free set, which includes a microphone 16 and an earphone or speaker 17 and which is connectable to a mobile phone. The third contact member 13 of the adapter comprises a third female contact member in the form of a jack adapted to receive a plug of a mobile phone hands-free set and mounted in the casing 2. The third contact member 14 of the second unit 15 comprises a third male contact member in the form of a mobile phone hands-free plug.

The electric circuit 3,4 has a first pole 21 and a second pole 22. The second contact member 8 of the adapter has a first pole 25 connected to the first pole 21 of the electric circuit 3,4 and a second pole 26 connected to the second pole 22 of the electric circuit 3,4. The third contact member 13 of the adapter has a first pole 27 connected to the first pole 21 of the electric circuit 3,4 and a second pole 29 connected to the second pole 22 of the electric circuit 3,4. The first contact member 5 of the adapter has a first pole 23, which is directly connected to a third pole 28 of the third contact member 13 of the adapter, and a

second pole 24, which is directly connected to the second pole 29 of the third contact member 13 of the adapter.

The electric circuit 3,4 will in operation adapt the microphone signal of the hands-free set of the second unit 15 to the microphone input signal required by the electronic device, such as a computer, of the first unit 7.

The second embodiment disclosed in Fig 2 differs from the first embodiment only in that the third contact member 13 is adapted to another standard mobile phone hands-free plug, wherein the third contact member 13 includes four separate poles 27,28,29,30 instead of three separate poles. Two of the poles 27,29 are connected to the poles 21 and 22, respectively, of the electric circuit 3,4, and the two other poles 28,30 are directly connected to a respective pole 23, 24 of the first contact member 5.

The third embodiment disclosed in Fig 3 differs from the first embodiment in that the first contact member 5 of the adapter is designed as a female output contact member in the form of a standard earphone jack. Moreover, the second contact member 8 of the adapter is designed as a female input contact member in the form of a standard microphone jack. The adapter is connected to the first unit 7 in the form of said electronic device via standard cable members 10 and 11. The cable member 10 has a standard earphone plug 6 to be connected to the jack 5, and the cable member 11 has a standard microphone plug 9 to be connected to the jack 8.

The third embodiment also permits the first unit 7 to be realised as a standard headset having a microphone or a speaker. The headset has a separate speaker plug 6 to be connected to the first female contact member 5 of the adapter and a separate microphone plug 9 to be connected to the second female contact member 8 of the adapter. The

second unit 15 may then be realised by a mobile phone connected to the third contact member 13 via a standard mobile phone plug 14. Consequently, the third embodiment of the adapter makes it possible to use any standard headset together with a mobile phone.

The fourth embodiment disclosed in Fig 4 differs from the third embodiment only in that the third contact member 13 is adapted to another standard mobile phone plug, wherein the third contact member 13 includes four separate poles 27,28, 29,30 instead of three separate poles. Two of the poles 27, 29 are connected to the poles 21 and 22, respectively, of the electric circuit 3,4, and the two other poles 28,30 are directly connected to a respective pole 23, 24 of the first contact member 5. For the sake of simplicity, the first unit 7 and the second unit 15 are not disclosed in Fig 4.

The fifth embodiment disclosed in Fig 5 includes an adapter unit 1 comprising a first adapter portion 1'and a second adapter portion 1". The first adapter portion 1' corresponds to the adapter unit 1 of the first embodiment.

The two adapter portions 1'and 1''may be included in the same casing 2 or may be included in a respective separate casing, which is indicated by the partition line 2'. These two separate adapter casings may then be connectable to each other to form a single unit. The second adapter portion If' comprises a fourth contact member 41 connectable to a contact member of a separate earphone or speaker or to an earphone or speaker of a standard headset 43. The second adapter portion 1"also comprises a fifth contact member 42, which, for instance, may be connected to the electric circuit 3,4 by means of an additional conduit 44. The fifth contact 42 member is also connectable to a separate microphone or a microphone of said headset 43. The fourth contact member 41 may, for instance, be directly connected to first contact member 5 via a short circuit conduit 45.

The fourth contact member is a standard female earphone or speaker jack. The fifth contact member 42 is a standard female microphone jack.

Moreover, the adapter portion 1''comprises a sixth contact member 50, which is connected to the electric circuit 3,4 by means of the additional conduit 44 and connectable to a mobile phone 51. The sixth contact member 50 is standard mobile phone plug arranged to be received by a contact member of the mobile phone 51 in the form of a standard mobile phone jack. Consequently, the adapter of to the fifth embodiment may be connect a standard headset 43, a mobile phone hands-free 15, an electronic device such as a computer 7, and a mobile phone 51 to each other in an optional manner. Thus, a user can select to operate the computer by means of the headset or the hands-free set, and/or to operate the mobile phone by means of the headset 43 or the hands-free set 15. It is also possible to switch between operation of the mobile phone 51 or the computer 7, for instance.

The sixth embodiment disclosed in Fig 6 differs from the fifth embodiment only in that the mobile phone jack 50 and the hands-free jack 13 are adapted to another mobile phone standard including four poles in a manner corresponding the second embodiment and the fourth embodiment. For the sake of simplicity, the first unit 7 and the second unit 15 are not disclosed in Fig 4.

The present invention is not limited to the embodiments disclosed herein but may be varied and modified within the scope of the following claims. The adapter is preferably handled as a separate adapter unit. However, it is to be noted that the adapter may also be realised as an adapter unit integrated in any suitable electronic device, such as a computer. Moreover, the adapter can include a plurality of

the second contact members 13 in the form of mobile phone jacks of different kinds, for example the jack13 disclosed in Figs 1 and 2. Then the adapter can be used with various kinds mobile phones from different mobile phone producers.